高速铁路饱和粉土液化地基抗震加固试验研究
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摘要
我国是地震多发国家,历史上发生六级以上地震的地震带多达23个,其中五个地震带非常活跃,这五个地震带正在进入活跃期,其分布区域遍及我国的东北、华北、青藏高原南部和西南地区。大量的宏观震害调查表明：在液化区内,地基土的地震液化是引起上部结构物及构造物破坏的主要原因之一,由于直接振动而引起的结构震害则很少,甚至没有。因此,液化造成灾害的严重性很早就得到了人们的关注。
京沪通道是维系我国国民经济发展的大动脉,是连接京津地区和长江三角洲两大经济区的枢纽,京沪地区GDP占全国总量的40%,沿线人口占全国人口1/4以上。建设京沪高速铁路对缓解既有京沪铁路运力长期严重紧张局面,形成我国铁路客运专线网,促进我国经济社会发展具有重要意义。
从京沪高速铁路地层勘查结果看出,该线路须经过大面积液化土区域,且这些区域位于7～9度高烈度区,在地震作用下均可能发生液化。根据“小震不坏,中震可修,大震不倒”的设计原则,为防止因地震引起的地基土液化、路基破坏和沉降,导致列车长期中断运行,有必要对高速铁路液化土地基抗震加固技术进行深入的研究。
本文结合京沪高速铁路的建设,开展了对饱和粉土地基这一类可液化土地基在地震作用下的动力特性研究,提出了一种新型液化土地基-路基抗震加固结构,使用了碎石桩桩网加固工法和CFG桩桩网加固工法对高速铁路饱和粉土液化地基进行了初步设计,并通过室内动三轴试验、大比例模型振动台试验以及数值模拟等方法,对加固前后的饱和粉土地基动力特性和地基路基整体抗震稳定性进行了深入的研究,得出了以下结论：
(1)通过三轴剪切试验研究了饱和粉土加固前后的静力强度和应力应变特性,试验结果表明：
①加固前(干密度1.46g/cm3,下同)的饱和粉土应力应变曲线呈典型应变硬化性曲线,而加固后(干密度1.586g/cm3,下同)的饱和粉土应力应变曲线呈软化型特征；
②饱和粉土的抗剪强度随围压的增加而增大,且加固后的饱和粉土各项强度指标均较加固前有所提高,说明固结围压和密实度对于提高饱和粉土的抗剪切变形能力作用显著。
(2)通过循环振动三轴剪切试验,研究了高速铁路饱和粉土液化地基加固前后的液化动力特性,试验结果表明：
①饱和粉土动强度和液化强度随围压的增加而增大,随循环震次的增加而减小加固后饱和粉土的动强度和液化强度高于加固前,且围压越低,动强度和液化强度提高幅度越大,围压分别为50kPa、100kPa和150kPa时,加固后的饱和粉土动强度和液化强度分别提高了约5倍、3倍和2倍；
②饱和粉土动剪应力比随循环震次的增加而减小,加固后的饱和粉土动剪应力比大于加固前动剪应力比,所不同的是,加固前饱和粉土动剪应力比随围压的增加而增大,而加固后饱和粉土的动剪应力比却随围压的增加而减小,且围压越低,动剪应力比提高幅度越大；
③饱和粉土的振动孔压发展规律与初始固结围压无关；加固前饱和粉土孔压发展规律与砂土液化孔压发展规律比较一致,即在振动液化前期,大约占完全液化时间的80%的时间段内,孔压发展相对比较平缓,而在后期剩余的20%的时间段内,孔压迅速上升,并最终达到完全液化；加固后的饱和粉土孔压发展规律则完全不同,其在振动初期仅占完全液化时间的不到1/20的时间段内,孔压比迅速上升至0.6,而在随后的时间段内,孔压发展缓慢,整个孔压发展过程符合典型的幂指数发展规律；
④饱和粉土的动剪模量随动剪应变的增加而减小,动剪模量与动剪应变均呈双曲线关系,加固后饱和粉土的动剪模量大于加固前的动剪模量,并且动剪应变越小,动剪模量的提高幅度越大,当动剪应变大于10-2量级时,加固前后饱和粉土的动剪模量逐渐趋于一致；
⑤饱和粉土阻尼比随其动剪应变的增大而增大,阻尼比与动剪应变符合双曲线模型,加固后的饱和粉土阻尼比要小于加固前的阻尼比,且动剪应变越大,阻尼比减小幅度越大。
(3)针对饱和粉土这一类可液化地基,提出了一种新型液化土地基-路基抗震加固结构,通过大比例模型振动台试验进行了加固效果的验证,申请并获得了相关专利。该结构包括加固桩、水泥级配碎石加筋垫层和加筋土路堤三部分,整体结构使得桩-水泥级配碎石加筋垫层结构地基与加筋路堤本体联结成一个相互作用的有机整体,增加了地震时地基-水泥级配碎石加筋垫层-路基的变形协调性,大大提高了地基路基的整体抗震性能；参照上述加固结构,以沉降变形为控制原则,分别采用了碎石桩桩网结构和CFG桩桩网结构两种加固形式对京沪高铁饱和粉土液化地基进行了初步设计。
(4)通过大比例模型振动台试验,首次对高速铁路饱和粉土液化地基加固前后的响应加速度、超静孔压、剪切变形、垫层和路堤土工格栅应变、地基路基沉降变形和地基内部液化流动等方面进行了综合分析与验证,试验结果表明：
①对于同一测点来说,当加载加速度增大时,其响应加速度也随之增大；当加载加速度逐渐增大到一定值时,地基中同一竖直线上各测点的响应加速度随距离振动台台面高度的增加而增大,在黏土层中,响应加速度几乎与台面加速度相当或者增加很小,但在粉土层中,响应加速度的增加速率很快,说明粉土液化对响应加速度起到了放大作用,但黏土层却对此几乎没有影响；
②未加固地基的响应加速度放大系数分布云图在两侧路肩之间的地基路基范围内(Ⅰ区)呈现上凸状,并且随加载加速度的增加,上凸愈加明显,尤其是路堤部分放大系数云图更是呈尖凸状,在两侧边坡覆盖范围内(Ⅱ区)响应加速度放大系数分布云图基本呈水平状；而加固后的地基,响应加速度放大系数分布云图在Ⅰ区基本呈现水平状或微凸状分布,在Ⅱ区呈衰减型趋势。这说明加固措施的使用,提高地基路基的整体刚度的一致性,明显减小了路基中心与两侧路肩之间地基路基(Ⅰ区)的响应加速度差异,使得地基路基的动力响应趋于均衡,增加了其整体的抗震性能；
③未加固地基和CFG桩桩网加固地基的响应加速度放大倍率随加载加速度的增大而先增大后减小直至趋于稳定,而碎石桩桩网加固地基却表现出与之不同的结果,其响应加速度放大倍率始终随加载加速度的增大而增大；在加载加速度不超过某个定值时,加固后的地基响应加速度倍率明显减小,且碎石桩桩网加固地基减小更为明显,说明碎石桩桩网加固地基更能有效抑制饱和粉土地基的加速度放大效应,提高地基的抗震性能；但当加载加速度超出这个定值时,碎石桩桩网加固地基的抗震效果却反而不及未加固地基,而CFG桩桩网加固地基对饱和粉土地基加速度放大的抑制作用依然优于未加固地基；
④同一竖直线上不同埋设深度处的超静孔压随埋设深度的增加而增大,同一水平线上不同位置处的超静孔压随距离路基中心水平距离的增大而减小；随着加载加速度的增加,地基中各点的超静孔压先逐渐增大到某一峰值孔压,然后随加载加速度的增加稍稍减小并趋于稳定,未加固地基、碎石桩桩网结构加固地基和CFG桩桩网加固地基达到超静孔压峰值所对应的加载加速度分别为0.283g、0.252g和0.161g,相同位置处的超静孔压峰值以未加固地基为最大,碎石桩桩网结构次之,CFG桩桩网结构最小,这同时也反映了地基土所承受的上覆有效应力以未加固地基为最大,碎石桩桩网结构次之,CFG桩桩网结构最小
⑤三种类型地基中黏土层的累积侧向剪切位移在各次加载时均处于较小水平,几乎不发生剪切变形。在加载加速度较小,不足以引起地基液化时,粉土层的累积侧向位移也几乎为零,但当加载加速度足以引起地基液化时,三种类型地基的粉土层累积侧向剪切位移均随距离台面高度的增大而大幅增加；三种类型地基最大剪切位移均随加载加速度的增大而增加；在加载加速度不大于约0.36g时,碎石桩桩网加固地基的最大剪切位移均小于其他两种类型地基,其抗剪切变形能力最强,CFG桩桩网加固地基次之,未加固地基的抗剪切变形能力最差；当加载加速大于0.36g时,加固处理后的地基最大剪切位移仍小于未加固地基,但碎石桩桩网地基的抗剪切变形能力却要弱于CFG桩桩网加固地基；
⑥垫层土工格栅最大应变随加载加速度的增加而先增大后逐渐趋于稳定,在各次加载时,未加固地基和CFG桩桩网加固地基垫层土工格栅最大应变均表现出中间大两侧小的特性,而碎石桩桩网加固地基垫层土工格栅最大应变分布则表现出中间小两侧大的特性,且分布最为均匀,未加固地基垫层土工格栅两侧应变差异最大；
⑦未加固地基和碎石桩桩网加固地基的路堤边坡中距离加筋垫层最近的一层土工格栅应变随加载加速度的变化趋势大致与加筋垫层土工格栅随加载加速度的变化趋势一致,但其应变绝对值与加筋垫层的格栅应变相比却很小,除此之外,边坡内其他各层土工格栅基本没有变形；对于CFG桩桩网加固地基,路堤边坡各层土工格栅的应变随加载加速度的变化均与加筋垫层土工格栅的应变发展规律十分相似,最大应变也与加筋垫层格栅应变相差不大,但各层格栅的应变大小却没有规律。
⑧随加载加速度的增大,路堤累积变形越来越大,未加固地基的路堤沉降、坡脚水平位移和竖向隆起最大,而加固地基的路堤累积变形明显减小,其中,碎石桩桩网加固地基的路堤变形最小
⑨对比三种类型地基加载结束后的最终累积沉降,未加固地基的最终累积沉降和差异沉降最大,CFG桩桩网加固地基次之,碎石桩桩网加固地基最小；
⑩对比三种类型地基内部液化流动情况,未加固地基除坡脚处发生上浮外,其他各处均有不同程度的下沉；加固后的地基浅层均有不同程度的下沉,地基深层则出现上浮,且同一水平位置的各浮球位移差异不大；对比加固后地基内部浮球位移情况,碎石桩桩网加固地基浅层沉降更小,且比较均匀,深层地基不同深度处桩间土上浮位移量差异最小；
(5)引入太沙基固结理论和砂井地基固结Barran解,结合循环振动三轴剪切试验所得到的液化动力特性和孔压增长曲线,首次推导了碎石桩桩网加固地基在地震作用下的孔压发展和消散的半解析解,计算结果与振动台试验结果一致性较好。
(6)采用有限元软件分析计算了加固前后地基液化区域的扩展及其抗震稳定性,结果表明：
①在相同级别输入加速度时,加固后的地基液化区域面积较加固前的地基液化区域面积明显减小,同等情况下,碎石桩桩网加固地基的液化区域面积最小,CFG桩桩网加固地基次之；
②三种类型地基路基的抗震稳定性最小安全系数均随输入加速度的增加而减小；未加固地基的整体抗震稳定性最小安全系数在各级输入加速度下均小于1.0,而加固后的地基整体抗震稳定性大幅度提高,在各级输入加速度下其最小安全系数均大于1.5,尤其是CFG桩桩网加固地基的抗震稳定性提高最为显著。
China is an earthquake-prone country, there are23seismic zones on which earthquakes (Ms≥6) occurred in history, five of which are very active and entering a period of earthquake. These seismic zones distribute in northeast china, north china, southwest china and south of the Qinghai-Tibet plateau. A large number of macro-earthquake damage surveys show that:in liquefied zones, destruction of the upper structure was mainly due to the soil liquefaction caused by earthquake; few or nothing is directly caused by earthquake. Therefore, the severity of liquefaction hazards has long been concerned.
The traffic channel between Beijing and Shanghai is an important artery to maintain china's economic development and it is also a transportation hub connecting Beijing-Tianjin region and Yangtze River Delta region, the two major economic zones of China. Beijing-Shanghai region's GDP accounts for40%of the national total and it's population accounts for over25%of the total, therefore, it is of great significance to carry out construction of Beijing-Shanghai High-Speed Railway, which can ease a serious shortage of long-term transportation capacity burdened by the existed Beijing-Shanghai railway, form national railway passenger line network, and promote social and economic development.
The results of geologic survey of Beijing-Shanghai High-Speed Railway area show that, a vast zone with liquefied saturated silt existed in this area which lies in highly seismic region of Ⅶ,Ⅷor Ⅸ. According to the principle of no break under light seismicity, repairable under intermediate seismicity and no collapse under intense seismicity, preventing long time interruption of trains resulted from foundation soil liquefaction, subgrade destroy and settlement during the earthquake, it is necessary to carry out a deep research on seismic reinforcement technology of liquefied foundation for High-Speed Railway.
Combined with the construction of Beijing-Shanghai High-Speed Railway, researches were carried out to study dynamic characteristics of saturated silt foundation under earthquake. A new seismic reinforced foundation-subgrade was proposed for liquefied region. And two types of foundation treatment corresponded to the new subgrade, gravel piles-net and CFG piles-net, were preliminary designed. Through a series of experiments including dynamic triaxial and large scale model shaking table tests, and numerical simulation, indepth research was conducted to study the dynamic characteristics and integral seismic stability of saturated silt foundation before and after being reinforced, and the following conclusions were obtained:
1. The results of triaxial shear tests studying on the static strength and stress-strain behavior of saturated silt before and after reinforcement are shown that:
1.1The stress-strain relationship of saturated silt before reinforcement(dry density1.46g/cm3, the same thereafter)shows a typical strain hardening curve, on the other hand it(dry density1.586g/cm3, the same thereafter) shows a strain softening curve after reinforcement;
1.2The shear strength of saturated silt increases with the increase of confining pressure, and after reinforcement all strength indexes of saturated silt are higher than those before reinforcement. The results indicate that consolidation confining pressure and density of saturated silt are important to improve resistance strength of silt to shear deformation.
2. The results of cyclic triaxial tests studying on the dynamic characteristics of saturated silt of High-Speed Railway before and after reinforcement for the first time are shown that:
2.1Both liquefaction strength and dynamic strength of saturated silt increase with the increase of confining pressure, and decrease with times of cyclic loading. Both liquefaction strength and dynamic strength of saturated silt after reinforcement are higher than those before reinforcement, and the lower confining pressure is, the greater increase rate of liquefaction strength and dynamic strength of reinforced saturated silt is, for instance, specimens under confining pressure of50kPa,100kPa and150kPa, the liquefaction strength and dynamic strength of reinforced saturated silt increase by about5times,3times and2times respectively, comparing with unreinforced specimens;
2.2Dynamic shear stress ratio of saturated silt decreases with times of cyclic loading, and dynamic shear stress ratio of reinforced saturated silt is higher than that of unreinforced silt. Dynamic shear stress ratio of unreinforced saturated silt increases with the increase of confining pressure, but reinforced silt decreases, and the lower confining pressure is, the greater increase rate of dynamic shear stress ratio is;
2.3The pore-water pressure development of saturated silt has nothing to do with the initial consolidation confining pressure:The development pattern of pore-water pressure of unreinforced saturated silt against time is the same as that of sand, namely, during pre-liquefaction, which accounts for about80%of the whole liquefaction period, the development of pore-water pressure is relatively flat, while the rest about20%of the liquefaction period, pore-water pressure increases rapidly and eventually gets full liquefaction; But for reinforced saturated silt, the development pattern of pore-water pressure is completely different from that of above, during of pre-liquefaction, which accounts for less than1/20of the liquefaction period, pore-water pressure increases rapidly to60%of its peak value, and then during the subsequent time, it slowly reaches the peak, the pore-water pressure development process of reinforced saturated silt is in line with the typical exponential law;
2.4The dynamic shear modulus of saturated silt decreases with the increase of its dynamic shear strain, and the curve of its dynamic shear modulus and dynamic shear strain shows a hyperbolic relationship; The dynamic shear modulus of reinforced silt is greater than that of unreinforced, and the smaller dynamic shear strain is, the greater increase rate of dynamic shear modulus is, when the magnitude of dynamic shear strain is greater than10-2, both of dynamic shear modulus of unreinforced and reinforced silt become more and more consistent;
2.5The damping ratio of saturated silt increases with the increase of its dynamic shear strain, and the curve of its damping ratio against dynamic shear strain is in line with the hyperbolic model. The damping ratio of reinforced saturated silt is less than that of unreinforced, and the larger dynamic shear strain is, the greater decrease rate of its damping ratio is.
3. For the saturated silt foundation which may be liquefied, a brand new patented foundation-subgrade structure was proposed. This structure included three parts-piles, cushion reinforced by cement, graded broken stone and geogrids and subgrade reinforced by geogrids. In the structure, subgrade, foundation reinforced by piles and cushion were connected into a whole interaction, which increased the deformation compatibility of foundation-cushion-subgrade during earthquake, and greatly improved the integral seismic performance of the foundation-subgrade; With reference to above reinforcement structure, on the principle of settlement deformation control, preliminary reinforcement designs were carried out for liquefied saturated soil foundation of Beijing-Shanghai High-Speed Railway by using two kinds reinforcement forms, gravel piles-net structure and CFG piles-net structure.
4. By lager-scale model shaking table tests, for the first time comprehensively analyzed and verified the characteristics of saturated soil liquefied foundation of High-Speed Railway before and after reinforcement, which included response acceleration, pore-water pressure, shear deformation, geogrids strain within cushion and subgrade, foundation-subgrade deformation and liquefaction flow within foundation etc, the results show that:
4.1For the same measured point, when table acceleration increases, response acceleration of the structure also increases. When table acceleration increases to a certain value, the response acceleration increases along the vertical profile of foundation from top to bottom. In the clay layer, the response acceleration is almost equal to table acceleration, however, in silt layer, the response acceleration increases quickly. It shows that silt soil liquefaction play a role in amplifying response acceleration but clay soil don't.
4.2For unreinforced foundation, the amplification coefficient contours of response acceleration show convexity in the foundation-subgrade under both sides of the shoulder(zone I), and the greater this convex curvature is, the greater table acceleration is, moreover, the contours even show sharp convex in the subgrade. However, the contours show horizontal in the foundation-subgrade under both sides of the slope (zone II). For reinforced foundation, the amplification coefficient contours of response acceleration show horizontal or slightly convex in zone I, and decaying trend in zone II. That show these reinforcement measures improve the consistency of the foundation-subgrade stiffness, significantly reduce the response acceleration difference between zone I and zone II, smooth dynamic response of foundation-subgrade and increase seismic performance of structure;
4.3With the increase of table acceleration, amplification coefficients of response acceleration of unreinforced foundation and CFG piles-net structure foundation first increase and then decrease to a stable value, but that of gravel piles-net structure foundation always increase; When table acceleration is less than a certain value, the amplification coefficients of response acceleration of reinforced foundation significantly reduce comparing with that of unreinforced foundation, and the coefficients decrease more apparent in the gravel piles-net foundation. The results show that:gravel piles-net structure is more effective on inhibiting the response acceleration from being amplified and improving the seismic performance of foundation than CFG piles-net structure in saturated silt foundation; However, when table acceleration exceeds this value, the seismic performance of foundation reinforced by gravel piles-net is worse than that of unreinforced, but that of reinforced by CFG piles-net is still better than that of unreinforced.
4.4Pore-water pressure increases vertically with the increase of its depth and decreases horizontally with the increase of its position from the center of subgrade; with the increase of table acceleration, pore-water pressures in foundation first increases to its peak, then decreases and at last tends to stabilize. When pore-water pressures of unreinforced foundation, gravel piles-net structure foundation and CFG piles-net structure foundation reach their peak, their corresponding table acceleration are0.283g,0.252g and0.161g, and in the same position, the pore-water pressure is the largest in unreinforced foundation, next is that in gravel piles-net structure foundation, and the smallest is that in CFG piles-net structure foundation.
4.5At each table acceleration level, the clay layer lateral shear displacement is small around zero. When table acceleration is too small to cause foundation liquefaction, the accumulative lateral displacement of silt layer is almost zero too, but when table acceleration is large enough to cause foundation liquefaction, lateral shear displacement increases with the increase of its vertical distance from the table; The maximum shear displacement increases with the increase of table acceleration; When table acceleration is less than about0.36g, the maximum shear displacement of gravel piles-net structure foundation is less than that of the other two types of foundations, it has the strongest resistance to shear deformation, followed by CFG piles-net structure foundation, the worst is unreinforced foundation; However, when table acceleration is more than about0.36g, the maximum shear displacement of reinforced foundation is still less than that of unreinforced, but the resistance to shear deformation of gravel piles-net structure foundation is less than that of CFG piles-net structure foundation;
4.6With the increase of table acceleration, the maximum geogrids strain of cushion first increases and then gradually stabilizes. The maximum geogrids strain distribution in unreinforced foundation and CFG piles-net structure foundation shows decreasing charact-eristics from the middle to both sides, but that in gravel piles-net structure foundation shows increasing characteristics from the middle to both sides and the most uniform, comparing with the largest geogrids strain difference between both sides and the middle in unreinforced foundation.
4.7In unreinforced foundation and gravel piles-net structure foundation, the geogrids strain in bottom layer of subgrade changes in line with that of the cushion geogrids with the increase of table acceleration, but its absolute value is very small comparing to the latter, in addition, the other layers geogrids have no deformation; For CFG piles-net structure foundation, the geogrids strain development in each layer of subgrade is similar to that in the cushion with the increase of table acceleration, its the maximum strain almost equals to the latter's, but the geogrids strain in each layer has no rule to follow.
4.8With the increase of table acceleration, the accumulated deformation of subgrade increases. At each table acceleration, the accumulated subgrade deformation of reinforced foundation, including subgrade settlement, horizontal and vertical displacement at the base of subgrade, significantly reduces comparing with that of unreinforced foundation, and that of gravel piles-net structure foundation is the smallest.
4.9Comparing the final accumulated deformation of the three types of foundations after loading, that of unreinforced foundation is the largest, followed by CFG piles-net structure foundation, the smallest is gravel piles-net structure foundation.
4.10In unreinforced foundation, in addition to showing uplift at the toe of slope, the others show different degrees of subsidence; In reinforced foundation, the upper foundation shows different degrees of subsidence, the subsoil shows uplift, and the vertical displace-ment of each float ball at the same horizontal level is almost the same; Comparing the floating balls displacement in reinforced foundation, the shallow settlement of gravel piles-net structure foundation is smaller and more even, the upward displacement difference is also smaller at different foundation depths;
5. Based on Terzaghi's consolidation theory and Barran's analytic solution of sand-drained ground consolidation, for the first time derived the semi-analytic solution of buildup and dissipation of pore-water pressures in gravel piles-net structure foundation subjected to earthquake, combined with the dynamic characteristics and the development pattern of pore-water pressures obtained by cyclic triaxial tests, and its results were in good agreement with the results of shaking table tests.
6. Using finite element software, analyzed liquefaction zone expansion and calculated integral seismic stability of the foundation-subgrade before and after reinforcement, then the results show that:
6.1At the same input acceleration, the liquefaction zone area of reinforced foundation reduces significantly than that of unreinforced, furthermore, the smallest liquefaction zone area is in gravel piles-net structure foundation and the next is in CFG piles-net structure foundation.
6.2The minimum safety factors of seismic stability of three types of foundations both decrease with the increase of input acceleration; At each input acceleration, the minimum safety factor of seismic stability of unreinforced foundation is less than1.0, and the integral seismic stability of reinforced foundation substantial increases and the minimum safety factor is greater than1.5, in particular, the seismic stability of CFG piles-net structure foundation improves the most significantly.
京沪通道是维系我国国民经济发展的大动脉,是连接京津地区和长江三角洲两大经济区的枢纽,京沪地区GDP占全国总量的40%,沿线人口占全国人口1/4以上。建设京沪高速铁路对缓解既有京沪铁路运力长期严重紧张局面,形成我国铁路客运专线网,促进我国经济社会发展具有重要意义。
从京沪高速铁路地层勘查结果看出,该线路须经过大面积液化土区域,且这些区域位于7～9度高烈度区,在地震作用下均可能发生液化。根据“小震不坏,中震可修,大震不倒”的设计原则,为防止因地震引起的地基土液化、路基破坏和沉降,导致列车长期中断运行,有必要对高速铁路液化土地基抗震加固技术进行深入的研究。
本文结合京沪高速铁路的建设,开展了对饱和粉土地基这一类可液化土地基在地震作用下的动力特性研究,提出了一种新型液化土地基-路基抗震加固结构,使用了碎石桩桩网加固工法和CFG桩桩网加固工法对高速铁路饱和粉土液化地基进行了初步设计,并通过室内动三轴试验、大比例模型振动台试验以及数值模拟等方法,对加固前后的饱和粉土地基动力特性和地基路基整体抗震稳定性进行了深入的研究,得出了以下结论：
(1)通过三轴剪切试验研究了饱和粉土加固前后的静力强度和应力应变特性,试验结果表明：
①加固前(干密度1.46g/cm3,下同)的饱和粉土应力应变曲线呈典型应变硬化性曲线,而加固后(干密度1.586g/cm3,下同)的饱和粉土应力应变曲线呈软化型特征；
②饱和粉土的抗剪强度随围压的增加而增大,且加固后的饱和粉土各项强度指标均较加固前有所提高,说明固结围压和密实度对于提高饱和粉土的抗剪切变形能力作用显著。
(2)通过循环振动三轴剪切试验,研究了高速铁路饱和粉土液化地基加固前后的液化动力特性,试验结果表明：
①饱和粉土动强度和液化强度随围压的增加而增大,随循环震次的增加而减小加固后饱和粉土的动强度和液化强度高于加固前,且围压越低,动强度和液化强度提高幅度越大,围压分别为50kPa、100kPa和150kPa时,加固后的饱和粉土动强度和液化强度分别提高了约5倍、3倍和2倍；
②饱和粉土动剪应力比随循环震次的增加而减小,加固后的饱和粉土动剪应力比大于加固前动剪应力比,所不同的是,加固前饱和粉土动剪应力比随围压的增加而增大,而加固后饱和粉土的动剪应力比却随围压的增加而减小,且围压越低,动剪应力比提高幅度越大；
③饱和粉土的振动孔压发展规律与初始固结围压无关；加固前饱和粉土孔压发展规律与砂土液化孔压发展规律比较一致,即在振动液化前期,大约占完全液化时间的80%的时间段内,孔压发展相对比较平缓,而在后期剩余的20%的时间段内,孔压迅速上升,并最终达到完全液化；加固后的饱和粉土孔压发展规律则完全不同,其在振动初期仅占完全液化时间的不到1/20的时间段内,孔压比迅速上升至0.6,而在随后的时间段内,孔压发展缓慢,整个孔压发展过程符合典型的幂指数发展规律；
④饱和粉土的动剪模量随动剪应变的增加而减小,动剪模量与动剪应变均呈双曲线关系,加固后饱和粉土的动剪模量大于加固前的动剪模量,并且动剪应变越小,动剪模量的提高幅度越大,当动剪应变大于10-2量级时,加固前后饱和粉土的动剪模量逐渐趋于一致；
⑤饱和粉土阻尼比随其动剪应变的增大而增大,阻尼比与动剪应变符合双曲线模型,加固后的饱和粉土阻尼比要小于加固前的阻尼比,且动剪应变越大,阻尼比减小幅度越大。
(3)针对饱和粉土这一类可液化地基,提出了一种新型液化土地基-路基抗震加固结构,通过大比例模型振动台试验进行了加固效果的验证,申请并获得了相关专利。该结构包括加固桩、水泥级配碎石加筋垫层和加筋土路堤三部分,整体结构使得桩-水泥级配碎石加筋垫层结构地基与加筋路堤本体联结成一个相互作用的有机整体,增加了地震时地基-水泥级配碎石加筋垫层-路基的变形协调性,大大提高了地基路基的整体抗震性能；参照上述加固结构,以沉降变形为控制原则,分别采用了碎石桩桩网结构和CFG桩桩网结构两种加固形式对京沪高铁饱和粉土液化地基进行了初步设计。
(4)通过大比例模型振动台试验,首次对高速铁路饱和粉土液化地基加固前后的响应加速度、超静孔压、剪切变形、垫层和路堤土工格栅应变、地基路基沉降变形和地基内部液化流动等方面进行了综合分析与验证,试验结果表明：
①对于同一测点来说,当加载加速度增大时,其响应加速度也随之增大；当加载加速度逐渐增大到一定值时,地基中同一竖直线上各测点的响应加速度随距离振动台台面高度的增加而增大,在黏土层中,响应加速度几乎与台面加速度相当或者增加很小,但在粉土层中,响应加速度的增加速率很快,说明粉土液化对响应加速度起到了放大作用,但黏土层却对此几乎没有影响；
②未加固地基的响应加速度放大系数分布云图在两侧路肩之间的地基路基范围内(Ⅰ区)呈现上凸状,并且随加载加速度的增加,上凸愈加明显,尤其是路堤部分放大系数云图更是呈尖凸状,在两侧边坡覆盖范围内(Ⅱ区)响应加速度放大系数分布云图基本呈水平状；而加固后的地基,响应加速度放大系数分布云图在Ⅰ区基本呈现水平状或微凸状分布,在Ⅱ区呈衰减型趋势。这说明加固措施的使用,提高地基路基的整体刚度的一致性,明显减小了路基中心与两侧路肩之间地基路基(Ⅰ区)的响应加速度差异,使得地基路基的动力响应趋于均衡,增加了其整体的抗震性能；
③未加固地基和CFG桩桩网加固地基的响应加速度放大倍率随加载加速度的增大而先增大后减小直至趋于稳定,而碎石桩桩网加固地基却表现出与之不同的结果,其响应加速度放大倍率始终随加载加速度的增大而增大；在加载加速度不超过某个定值时,加固后的地基响应加速度倍率明显减小,且碎石桩桩网加固地基减小更为明显,说明碎石桩桩网加固地基更能有效抑制饱和粉土地基的加速度放大效应,提高地基的抗震性能；但当加载加速度超出这个定值时,碎石桩桩网加固地基的抗震效果却反而不及未加固地基,而CFG桩桩网加固地基对饱和粉土地基加速度放大的抑制作用依然优于未加固地基；
④同一竖直线上不同埋设深度处的超静孔压随埋设深度的增加而增大,同一水平线上不同位置处的超静孔压随距离路基中心水平距离的增大而减小；随着加载加速度的增加,地基中各点的超静孔压先逐渐增大到某一峰值孔压,然后随加载加速度的增加稍稍减小并趋于稳定,未加固地基、碎石桩桩网结构加固地基和CFG桩桩网加固地基达到超静孔压峰值所对应的加载加速度分别为0.283g、0.252g和0.161g,相同位置处的超静孔压峰值以未加固地基为最大,碎石桩桩网结构次之,CFG桩桩网结构最小,这同时也反映了地基土所承受的上覆有效应力以未加固地基为最大,碎石桩桩网结构次之,CFG桩桩网结构最小
⑤三种类型地基中黏土层的累积侧向剪切位移在各次加载时均处于较小水平,几乎不发生剪切变形。在加载加速度较小,不足以引起地基液化时,粉土层的累积侧向位移也几乎为零,但当加载加速度足以引起地基液化时,三种类型地基的粉土层累积侧向剪切位移均随距离台面高度的增大而大幅增加；三种类型地基最大剪切位移均随加载加速度的增大而增加；在加载加速度不大于约0.36g时,碎石桩桩网加固地基的最大剪切位移均小于其他两种类型地基,其抗剪切变形能力最强,CFG桩桩网加固地基次之,未加固地基的抗剪切变形能力最差；当加载加速大于0.36g时,加固处理后的地基最大剪切位移仍小于未加固地基,但碎石桩桩网地基的抗剪切变形能力却要弱于CFG桩桩网加固地基；
⑥垫层土工格栅最大应变随加载加速度的增加而先增大后逐渐趋于稳定,在各次加载时,未加固地基和CFG桩桩网加固地基垫层土工格栅最大应变均表现出中间大两侧小的特性,而碎石桩桩网加固地基垫层土工格栅最大应变分布则表现出中间小两侧大的特性,且分布最为均匀,未加固地基垫层土工格栅两侧应变差异最大；
⑦未加固地基和碎石桩桩网加固地基的路堤边坡中距离加筋垫层最近的一层土工格栅应变随加载加速度的变化趋势大致与加筋垫层土工格栅随加载加速度的变化趋势一致,但其应变绝对值与加筋垫层的格栅应变相比却很小,除此之外,边坡内其他各层土工格栅基本没有变形；对于CFG桩桩网加固地基,路堤边坡各层土工格栅的应变随加载加速度的变化均与加筋垫层土工格栅的应变发展规律十分相似,最大应变也与加筋垫层格栅应变相差不大,但各层格栅的应变大小却没有规律。
⑧随加载加速度的增大,路堤累积变形越来越大,未加固地基的路堤沉降、坡脚水平位移和竖向隆起最大,而加固地基的路堤累积变形明显减小,其中,碎石桩桩网加固地基的路堤变形最小
⑨对比三种类型地基加载结束后的最终累积沉降,未加固地基的最终累积沉降和差异沉降最大,CFG桩桩网加固地基次之,碎石桩桩网加固地基最小；
⑩对比三种类型地基内部液化流动情况,未加固地基除坡脚处发生上浮外,其他各处均有不同程度的下沉；加固后的地基浅层均有不同程度的下沉,地基深层则出现上浮,且同一水平位置的各浮球位移差异不大；对比加固后地基内部浮球位移情况,碎石桩桩网加固地基浅层沉降更小,且比较均匀,深层地基不同深度处桩间土上浮位移量差异最小；
(5)引入太沙基固结理论和砂井地基固结Barran解,结合循环振动三轴剪切试验所得到的液化动力特性和孔压增长曲线,首次推导了碎石桩桩网加固地基在地震作用下的孔压发展和消散的半解析解,计算结果与振动台试验结果一致性较好。
(6)采用有限元软件分析计算了加固前后地基液化区域的扩展及其抗震稳定性,结果表明：
①在相同级别输入加速度时,加固后的地基液化区域面积较加固前的地基液化区域面积明显减小,同等情况下,碎石桩桩网加固地基的液化区域面积最小,CFG桩桩网加固地基次之；
②三种类型地基路基的抗震稳定性最小安全系数均随输入加速度的增加而减小；未加固地基的整体抗震稳定性最小安全系数在各级输入加速度下均小于1.0,而加固后的地基整体抗震稳定性大幅度提高,在各级输入加速度下其最小安全系数均大于1.5,尤其是CFG桩桩网加固地基的抗震稳定性提高最为显著。
China is an earthquake-prone country, there are23seismic zones on which earthquakes (Ms≥6) occurred in history, five of which are very active and entering a period of earthquake. These seismic zones distribute in northeast china, north china, southwest china and south of the Qinghai-Tibet plateau. A large number of macro-earthquake damage surveys show that:in liquefied zones, destruction of the upper structure was mainly due to the soil liquefaction caused by earthquake; few or nothing is directly caused by earthquake. Therefore, the severity of liquefaction hazards has long been concerned.
The traffic channel between Beijing and Shanghai is an important artery to maintain china's economic development and it is also a transportation hub connecting Beijing-Tianjin region and Yangtze River Delta region, the two major economic zones of China. Beijing-Shanghai region's GDP accounts for40%of the national total and it's population accounts for over25%of the total, therefore, it is of great significance to carry out construction of Beijing-Shanghai High-Speed Railway, which can ease a serious shortage of long-term transportation capacity burdened by the existed Beijing-Shanghai railway, form national railway passenger line network, and promote social and economic development.
The results of geologic survey of Beijing-Shanghai High-Speed Railway area show that, a vast zone with liquefied saturated silt existed in this area which lies in highly seismic region of Ⅶ,Ⅷor Ⅸ. According to the principle of no break under light seismicity, repairable under intermediate seismicity and no collapse under intense seismicity, preventing long time interruption of trains resulted from foundation soil liquefaction, subgrade destroy and settlement during the earthquake, it is necessary to carry out a deep research on seismic reinforcement technology of liquefied foundation for High-Speed Railway.
Combined with the construction of Beijing-Shanghai High-Speed Railway, researches were carried out to study dynamic characteristics of saturated silt foundation under earthquake. A new seismic reinforced foundation-subgrade was proposed for liquefied region. And two types of foundation treatment corresponded to the new subgrade, gravel piles-net and CFG piles-net, were preliminary designed. Through a series of experiments including dynamic triaxial and large scale model shaking table tests, and numerical simulation, indepth research was conducted to study the dynamic characteristics and integral seismic stability of saturated silt foundation before and after being reinforced, and the following conclusions were obtained:
1. The results of triaxial shear tests studying on the static strength and stress-strain behavior of saturated silt before and after reinforcement are shown that:
1.1The stress-strain relationship of saturated silt before reinforcement(dry density1.46g/cm3, the same thereafter)shows a typical strain hardening curve, on the other hand it(dry density1.586g/cm3, the same thereafter) shows a strain softening curve after reinforcement;
1.2The shear strength of saturated silt increases with the increase of confining pressure, and after reinforcement all strength indexes of saturated silt are higher than those before reinforcement. The results indicate that consolidation confining pressure and density of saturated silt are important to improve resistance strength of silt to shear deformation.
2. The results of cyclic triaxial tests studying on the dynamic characteristics of saturated silt of High-Speed Railway before and after reinforcement for the first time are shown that:
2.1Both liquefaction strength and dynamic strength of saturated silt increase with the increase of confining pressure, and decrease with times of cyclic loading. Both liquefaction strength and dynamic strength of saturated silt after reinforcement are higher than those before reinforcement, and the lower confining pressure is, the greater increase rate of liquefaction strength and dynamic strength of reinforced saturated silt is, for instance, specimens under confining pressure of50kPa,100kPa and150kPa, the liquefaction strength and dynamic strength of reinforced saturated silt increase by about5times,3times and2times respectively, comparing with unreinforced specimens;
2.2Dynamic shear stress ratio of saturated silt decreases with times of cyclic loading, and dynamic shear stress ratio of reinforced saturated silt is higher than that of unreinforced silt. Dynamic shear stress ratio of unreinforced saturated silt increases with the increase of confining pressure, but reinforced silt decreases, and the lower confining pressure is, the greater increase rate of dynamic shear stress ratio is;
2.3The pore-water pressure development of saturated silt has nothing to do with the initial consolidation confining pressure:The development pattern of pore-water pressure of unreinforced saturated silt against time is the same as that of sand, namely, during pre-liquefaction, which accounts for about80%of the whole liquefaction period, the development of pore-water pressure is relatively flat, while the rest about20%of the liquefaction period, pore-water pressure increases rapidly and eventually gets full liquefaction; But for reinforced saturated silt, the development pattern of pore-water pressure is completely different from that of above, during of pre-liquefaction, which accounts for less than1/20of the liquefaction period, pore-water pressure increases rapidly to60%of its peak value, and then during the subsequent time, it slowly reaches the peak, the pore-water pressure development process of reinforced saturated silt is in line with the typical exponential law;
2.4The dynamic shear modulus of saturated silt decreases with the increase of its dynamic shear strain, and the curve of its dynamic shear modulus and dynamic shear strain shows a hyperbolic relationship; The dynamic shear modulus of reinforced silt is greater than that of unreinforced, and the smaller dynamic shear strain is, the greater increase rate of dynamic shear modulus is, when the magnitude of dynamic shear strain is greater than10-2, both of dynamic shear modulus of unreinforced and reinforced silt become more and more consistent;
2.5The damping ratio of saturated silt increases with the increase of its dynamic shear strain, and the curve of its damping ratio against dynamic shear strain is in line with the hyperbolic model. The damping ratio of reinforced saturated silt is less than that of unreinforced, and the larger dynamic shear strain is, the greater decrease rate of its damping ratio is.
3. For the saturated silt foundation which may be liquefied, a brand new patented foundation-subgrade structure was proposed. This structure included three parts-piles, cushion reinforced by cement, graded broken stone and geogrids and subgrade reinforced by geogrids. In the structure, subgrade, foundation reinforced by piles and cushion were connected into a whole interaction, which increased the deformation compatibility of foundation-cushion-subgrade during earthquake, and greatly improved the integral seismic performance of the foundation-subgrade; With reference to above reinforcement structure, on the principle of settlement deformation control, preliminary reinforcement designs were carried out for liquefied saturated soil foundation of Beijing-Shanghai High-Speed Railway by using two kinds reinforcement forms, gravel piles-net structure and CFG piles-net structure.
4. By lager-scale model shaking table tests, for the first time comprehensively analyzed and verified the characteristics of saturated soil liquefied foundation of High-Speed Railway before and after reinforcement, which included response acceleration, pore-water pressure, shear deformation, geogrids strain within cushion and subgrade, foundation-subgrade deformation and liquefaction flow within foundation etc, the results show that:
4.1For the same measured point, when table acceleration increases, response acceleration of the structure also increases. When table acceleration increases to a certain value, the response acceleration increases along the vertical profile of foundation from top to bottom. In the clay layer, the response acceleration is almost equal to table acceleration, however, in silt layer, the response acceleration increases quickly. It shows that silt soil liquefaction play a role in amplifying response acceleration but clay soil don't.
4.2For unreinforced foundation, the amplification coefficient contours of response acceleration show convexity in the foundation-subgrade under both sides of the shoulder(zone I), and the greater this convex curvature is, the greater table acceleration is, moreover, the contours even show sharp convex in the subgrade. However, the contours show horizontal in the foundation-subgrade under both sides of the slope (zone II). For reinforced foundation, the amplification coefficient contours of response acceleration show horizontal or slightly convex in zone I, and decaying trend in zone II. That show these reinforcement measures improve the consistency of the foundation-subgrade stiffness, significantly reduce the response acceleration difference between zone I and zone II, smooth dynamic response of foundation-subgrade and increase seismic performance of structure;
4.3With the increase of table acceleration, amplification coefficients of response acceleration of unreinforced foundation and CFG piles-net structure foundation first increase and then decrease to a stable value, but that of gravel piles-net structure foundation always increase; When table acceleration is less than a certain value, the amplification coefficients of response acceleration of reinforced foundation significantly reduce comparing with that of unreinforced foundation, and the coefficients decrease more apparent in the gravel piles-net foundation. The results show that:gravel piles-net structure is more effective on inhibiting the response acceleration from being amplified and improving the seismic performance of foundation than CFG piles-net structure in saturated silt foundation; However, when table acceleration exceeds this value, the seismic performance of foundation reinforced by gravel piles-net is worse than that of unreinforced, but that of reinforced by CFG piles-net is still better than that of unreinforced.
4.4Pore-water pressure increases vertically with the increase of its depth and decreases horizontally with the increase of its position from the center of subgrade; with the increase of table acceleration, pore-water pressures in foundation first increases to its peak, then decreases and at last tends to stabilize. When pore-water pressures of unreinforced foundation, gravel piles-net structure foundation and CFG piles-net structure foundation reach their peak, their corresponding table acceleration are0.283g,0.252g and0.161g, and in the same position, the pore-water pressure is the largest in unreinforced foundation, next is that in gravel piles-net structure foundation, and the smallest is that in CFG piles-net structure foundation.
4.5At each table acceleration level, the clay layer lateral shear displacement is small around zero. When table acceleration is too small to cause foundation liquefaction, the accumulative lateral displacement of silt layer is almost zero too, but when table acceleration is large enough to cause foundation liquefaction, lateral shear displacement increases with the increase of its vertical distance from the table; The maximum shear displacement increases with the increase of table acceleration; When table acceleration is less than about0.36g, the maximum shear displacement of gravel piles-net structure foundation is less than that of the other two types of foundations, it has the strongest resistance to shear deformation, followed by CFG piles-net structure foundation, the worst is unreinforced foundation; However, when table acceleration is more than about0.36g, the maximum shear displacement of reinforced foundation is still less than that of unreinforced, but the resistance to shear deformation of gravel piles-net structure foundation is less than that of CFG piles-net structure foundation;
4.6With the increase of table acceleration, the maximum geogrids strain of cushion first increases and then gradually stabilizes. The maximum geogrids strain distribution in unreinforced foundation and CFG piles-net structure foundation shows decreasing charact-eristics from the middle to both sides, but that in gravel piles-net structure foundation shows increasing characteristics from the middle to both sides and the most uniform, comparing with the largest geogrids strain difference between both sides and the middle in unreinforced foundation.
4.7In unreinforced foundation and gravel piles-net structure foundation, the geogrids strain in bottom layer of subgrade changes in line with that of the cushion geogrids with the increase of table acceleration, but its absolute value is very small comparing to the latter, in addition, the other layers geogrids have no deformation; For CFG piles-net structure foundation, the geogrids strain development in each layer of subgrade is similar to that in the cushion with the increase of table acceleration, its the maximum strain almost equals to the latter's, but the geogrids strain in each layer has no rule to follow.
4.8With the increase of table acceleration, the accumulated deformation of subgrade increases. At each table acceleration, the accumulated subgrade deformation of reinforced foundation, including subgrade settlement, horizontal and vertical displacement at the base of subgrade, significantly reduces comparing with that of unreinforced foundation, and that of gravel piles-net structure foundation is the smallest.
4.9Comparing the final accumulated deformation of the three types of foundations after loading, that of unreinforced foundation is the largest, followed by CFG piles-net structure foundation, the smallest is gravel piles-net structure foundation.
4.10In unreinforced foundation, in addition to showing uplift at the toe of slope, the others show different degrees of subsidence; In reinforced foundation, the upper foundation shows different degrees of subsidence, the subsoil shows uplift, and the vertical displace-ment of each float ball at the same horizontal level is almost the same; Comparing the floating balls displacement in reinforced foundation, the shallow settlement of gravel piles-net structure foundation is smaller and more even, the upward displacement difference is also smaller at different foundation depths;
5. Based on Terzaghi's consolidation theory and Barran's analytic solution of sand-drained ground consolidation, for the first time derived the semi-analytic solution of buildup and dissipation of pore-water pressures in gravel piles-net structure foundation subjected to earthquake, combined with the dynamic characteristics and the development pattern of pore-water pressures obtained by cyclic triaxial tests, and its results were in good agreement with the results of shaking table tests.
6. Using finite element software, analyzed liquefaction zone expansion and calculated integral seismic stability of the foundation-subgrade before and after reinforcement, then the results show that:
6.1At the same input acceleration, the liquefaction zone area of reinforced foundation reduces significantly than that of unreinforced, furthermore, the smallest liquefaction zone area is in gravel piles-net structure foundation and the next is in CFG piles-net structure foundation.
6.2The minimum safety factors of seismic stability of three types of foundations both decrease with the increase of input acceleration; At each input acceleration, the minimum safety factor of seismic stability of unreinforced foundation is less than1.0, and the integral seismic stability of reinforced foundation substantial increases and the minimum safety factor is greater than1.5, in particular, the seismic stability of CFG piles-net structure foundation improves the most significantly.
引文
[1]胡聿贤.地震工程学[M].北京：地质出版社,2006.
[2]中国科技情报研究所.地基的地震效应和砂土液化译文选辑[M].北京：科学技术文献出版社,1978.
[3]陈一全,连峰,付飞营,等.黄河下游冲积粉土地震液化判别研究[J].山东建筑大学学报,2006,21(6)：490-491.
[4]钟龙辉.轻亚粘土地震液化判别方法的分析[J].岩土工程学报,1980,3(3)：.32-36.
[5]王余庆.轻亚粘土地震液化的判别[C]//地基与工业建筑抗震论文集.北京：地震出版社,1984.
[6]Ishihara K. Liquefaction and flow failure during earthquake[J]. Geotechnique,1993, 43(6):351-415.
[7]Seed H B. Design problems in soil liquefaction[J]. Journal of the Geotechnical Engineering Division, ASCE,1987,113(GT8):827-845.
[8]Seed H B, Booker J B. Stabilization of potentially liquefiable sand deposits using gravel drains[J]. Journal of the Geotechnical Engineering Division, ASCE,1977,103(GT7): 757-768.
[9]王晨燕.我国第一个史载文献最详细的8级地震-元朝山西省洪洞赵城地震[J].文史月刊,2010,No.7：10.
[10]师新明.国外地震砂土液化研究[J].铁道工程学报,1990,No.3：148.
[11]王景明.唐山地震的地面破坏效应[J].地震研究,1987,10(4)：451.
[12]刘恢先.唐山大地震震害(一)、(四)[M].北京：地震出版社,1986：339、393.
[13]孙锐,袁晓铭.第11届国际土动力学和地质工程会议及第13届世界地质工程会议砂土液化研究综述[J].世界地震工程,2006,22(1)：16-20.
[14]Casagrande A. Characteristics of cohesionless soils affecting the stability of slope and earth fills [J]. Journal of the Boston Society of Engineerings,1936,23(1):257-276.
[15]Casagrabde A. Liquefaction and cyclic deformation of sands, a critical review[C]// Proc.of 5th Pan-American conf. on Soil Mechanics and Foundation Engineering, Buenosaires:1975.
[16]Castro G. Liquefaction and cyclic mobility of saturated sands[J]. Journal of the Geotechnical Engineering Division, ASCE,1975,101(6):551-569.
[17]马斯洛夫.土力学问题(1954)[M].北京：建筑工程出版社,1959：1-85.
[18]HUANG Wen-xi. Investigation on stability of saturated sand foundation and slope against liquefaction[C]//Proc. of 5th international conf. on soil mechanics and foundation engineering, Paris,1961,Ⅱ:629-631.
[19]Seed H B, Lee K L. Liquefaction of saturated sands during cyclic loading[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1966,92(6):105-134.
[20]Seed H B. Soil liquefaction and cyclic mobility evaluation for level ground during earthquakes[J]. Journal of the Geotechnical Engineering Division, ASCE,1979, 105(2):201-255.
[21]Castro G. Liquefaction of Sands[M]. Cambridge:Harvard University,1969.
[22]Castro G, Seed H B, Keller T O, et al. Steady-state strength analysis of lower San Fernanda dam slide[J]. Journal of the Geotechnical Engineering Division, ASCE,1992, 118(3):406-427.
[23]谢定义.土动力学[M].西安：西安交通大学出版社,1988.
[24]Committee on Soil Mechanics of the Geotechnical Engineering Division. Definition of terms related to liquefaction by the Committee on Soil Mechanics of the Geotechnical Engineering Division[J]. Journal of the Geotechnical Engineering Division, ASCE, 1978,104(GT9):1-10.
[25]赵成刚,尤昌龙.饱和砂上液化与稳态强度[J].上木工程学报,2001,34(3)：90-96.
[26]鲁晓兵.垂直荷载作用下饱和砂土的液化分析[D].北京：中国科学院力学研究所,1999.
[27]汪文韶.土的动力强度和液化特性[M].北京：中国电力出版社,1995.
[28]Kramer S L, Seed H B. Initiation of soil liquefaction under static loading conditions [J]. Journal of Geotechnical Engineering, ASCE,1988,114(4):412-430.
[29]钱家欢.土工原理与计算[M].北京：中国水利水电出版社,1996：524.
[30]张克绪.饱和砂土的液化应力条件[J].地震工程与工程震动,1984,4(1)：100-108.
[31]刘成宇.土力学[M].北京：中国铁道出版社,2000：302-303.
[32]王星华,周海林.砂上液化动稳态强度分析[J].岩石力学与工程学报,2003,22(1)：96-102.
[33]聂守智.在动荷载作用下饱和砂土的液化及其强度[J].岩土工程学报,1980,2(3)：64-73.
[34]陈春霖,张慧明.饱和砂土三轴试验中的若干问题[J].岩土工程学报,2000,22(6)：660-663.
[35]ZHANG H. Steady state behavior of sands and limitations of the triaxial tests [D]. Ottawa:University of Ottawa,1997.
[36]Bishop A W, Green E G. The influence of end restraint on the compression strength of a cohesionless soil[J]. Geotechnique,1965,15(3):243-266.
[37]Roscoe K H, Schofield A N, Wroth C P. Correspondence on "On the yielding of soils" [J]. Geotechnique,1959,9(3):72.
[38]Lade P V. Initiation of static instability in the submarine Nerlerk berm[J]. Canadian Geotechnical Journal,1993,30(6):895-904.
[39]Lade P V. Static instability and liquefaction of loose fine sandy slopes[J]. Journal of Geotechnical Engineering, ASCE,1992,118(1):51-71.
[40]Lade P V, Yamamuro J A. Effects of nonplastic fines on static liquefaction of sands[J]. Canadian Geotechnical Journal,1997,34(6):918-928.
[41]Yamamuro J A, Lade P V. Static liquefaction of very loose sands[J]. Canadian Geo-technical Journal,1997,34(6):905-917.
[42]Seed H B, Tokimatsu K, Harder L F, et al. Influence of SPT procedures in soil liquefaction resistance evaluations[J]. Journal of Geotechnical Engineering, ASCE, 1985,111(12):1425-1445.
[43]Troncoso J H. Failure risks of abandoned tailings dams[C]//International Commission on Large Dams. Proc. Int. Sym. On Safety and rehabilitation of Tailings dams, Paris, 1990:82-89.
[44]Puri V K. Liquefaction behavior and dynamic properties loessial soils[D]. Columbia: University of MissouriRolla,1984.
[45]Puri V K. Liquefaction aspects of loessial soils[R]//EERI. Proc. of 4th US National Conference on Earthquake Engineering,1990,3:755-762.
[46]Sandoval J. Liquefaction and settlement characteristics of silty soils[D]. Columbia: University of MissouriRolla,1989.
[47]Prakash S, Sandoval J. Liquefaction of low plastic silts[J]. Soil Dynamic and Earthquake Engineering,1992,71(7):373-397.
[48]GUO Tian-qiang, Shamsher P. Liquefaction of silts and silt-clay mixtures[J]. Journal of Geotechnical Engineering, ASCE,1999,125(8):706-710.
[49]阮永芬,陈昆梅,韦敏才.粉土地震液化等级评判的人工神经网络技术应用[J],昆明理工大学学报,2000,25(4)：63-65.
[50]牛琪瑛,裘以惠,史美筠.粉土抗液化特性的试验研究[J].太原工业大学学报,1996,27(3)：5-9.
[51]Koester J P. Effects of fines type and content on liquefaction potential of low tomedium plasticity fine-grained soils[C]//Central United States Earthquake Consortium. Proc. of 19th Nat. Earthquake Conf, Tennessee,1993:67-75.
[52]甘霖.粉质壤土动三轴试验分析[C]//栾茂田.第五届全国土动力学学术会议论文集,大连：大连理工出版社,1998：176-180.
[53]Yamamuro J A, Covert K M. Monotonic and cyclic liquefaction of very loose sands with high silt content[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,2001,127(4):314-324.
[54]Polito C P, Martin Ⅱ J R. Effects of nonplastic fines on the liquefaction resistance of sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,2001, 127(5):408-415.
[55]Thevanayagam S, Fiorillo M, Liang J. Effect of non-plastic fines on undrained cyclic strength of silty sands[J]. Soil Dynamics and Liquefaction, ASCE,2000:77-91.
[56]Thevanayagam S. Effect of fines and confining stress on steady state strength of silty sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,1998, 124(6):479-491.
[57]Thevanayagam S, Mohan S. Intergranular state variables and stress-strain behavior of silty sands[J]. Geotechnique,2000,50(1),1-23.
[58]陈存礼,谢定义.偏应力往返作用下饱和砂上变形特性的试验研究[J].岩石力学与工程学报,2005,24(4)：669-675.
[59]陈存礼,谢定义.球应力往返作用下饱和砂土变形特性的试验研究[J].岩石力学与工程学报,2005,24(3)：513-520.
[60]陈存礼,谢定义.不排水条件下饱和砂土的应力比与应变比之间关系的试验研究[J].陕西水力发电,1999,15(2)：6-9.
[61]孔亮,段建立,郑颖人.慢速往复荷载下饱和砂土变形特性试验研究[J].工程勘察,2001,No.5：1-4.
[62]栾茂田,徐成顺,郭莹,等.静力与动力组合应力条件下饱和松砂变形特性的试验研究[J].土木工程学报,2005,38(3)：81-86.
[63]郭莹,栾茂田,何杨,等.主应力方向循环变化对饱和松砂不排水动力特性的影响[J].岩土工程学报,2005,27(4)：403-409.
[64]谢永涛,张鸿儒.不同路径下饱和砂土的动力特性模型[J].大坝观测与土工测试,2001,25(1)：43-45.
[65]孙锐,袁晓铭.地震荷载下饱和砂土孔压增长时程计算方法[J].地质工程与工程振动,2006,26(3)：261-263.
[66]王星华,周海林.固结比对饱和砂土液化的影响研究[J].中国铁道科学,2001,22(6)：121-126.
[67]周海林,王星华.动三轴实验中的饱和砂土孔隙水压力分析[J].铁道学报,2002, 24(6)：93-98.
[68]于濂洪,王波.饱和粉土振动孔隙水压力的试验研究[J].大连大学学报,1999,20(4)：59-62.
[69]于洪治.饱和粉土振动孔隙水压力发展规律[C]//吴世明.第四届全国土动力学学术会议论文集,杭州：浙江大学出版社,1994：107-110.
[70]冯秀丽,叶银灿,马艳霞,等.动荷载作用下海底粉土的孔压响应及其动强度[J].青岛海洋大学学报,2002,32(3)：429-433.
[71]曹宇春,王天龙.上海粉土液化特性及孔压模型的试验研究[J].上海地质,1998,67(3)：60-64.
[72]陈国兴,刘雪珠.南京粉质黏土与粉砂互层土及粉细砂的振动孔压发展规律研究[J].岩土工程学报,2004,26(1)：79-82.
[73]Alba P A, Chan C K, Seed H B. Sand liquefaction in large-scale simple shear tests [J]. Journal of the Geotechnical Engineering Division, ASCE,1976,102(9):909-927.
[74]左元明,郭家禄,魏汝龙.振动单剪仪的研制和调试[J].岩土工程学报,1980,2(1)：78-86.
[75]魏汝龙,郭家禄,左元明.往复荷载下饱和粉砂土中的孔隙水压力[J].土木工程学报,1983,16(1)：22-32.
[76]Sherif M A, Tsuchiya C, Ishibashi I. Saturation effects on initial soil liquefaction [J]. Journal of the Geotechnical Engineering Division, ASCE,1977,103(8):914-917
[77]Ishibashi I, Sherif M A. Soil liquefaction by torsional simple shear device[J]. Journal of the Geotechnical Engineering Division, ASCE,1974,100(8):871-888
[78]Alarcon-Guzman, Leonards G A, Chameau J L. Undrained monotonic and cyclic strength of sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE, 1988,114(10):1089-1109.
[79]徐干成,谢定义,郑泽民.饱和砂土振动扭剪孔隙水压力的研究[J].西北水资源与水工程,1992,3(2)：1-11.
[80]Finn W D L, Bhatia S K. Prediction of seismic pore-water pressures[C]//Proceedings of 10th International Conference on Soil Mechanics and Foundation Engineering, Rotterdam,1981,3:201-221.
[81]赵冬.振动扭剪试验中饱和砂的动力特性研究[J].岩土工程学报,1989,11(2)：88-94.
[82]Ishimoto M, Iida K. Determination of elastic constants of soils by means of vibration methods[J]. Bulletin of the Earthquake Research Institute, Tokyo Imperial University, 1937, Vol.15.
[83]Casagrande A, Corso J M, Wilson S D. Report to waterways experiment station on the 1949-1950 program of investigation of effect of long-time loading on the strength of clay and shales at constant water content[R]//Contract Report of U.S. Army Engineer Waterways Experiment Station, Cambridge:Harvard University,1950, No.3-3.
[84]Stevens H W. Suggested method of test for some viscoelastic properties of materials, especially frozen and nonfrozen soils, under vibratory loads[J]. Special Procedures for Testing Soil and Rock for Engineering Purposes,1970, No.6:530-546.
[85]Hardin B O, Drnevich V P. Shear modulus and damping in soil:Measurement and parameter effects[J]. Journal of the Soil Mechanics and Foundations Division, ASCE, 1972,98(6):603-624.
[86]徐瑞旻.共振柱试验程式视窗化之研究[D].台南：国立成功大学,2002.
[87]郭家禄,施萍.饱和砂剪切模量和阻尼比在GZ-1型共振柱仪上的测定[J].大坝观测与土工测试,1985,9(1)：44-49.
[88]姜朴,孙德安.砂土的共振柱试验与液化剪应力[J].水利学报,1987,No.7：68-70.
[89]Yokel F Y, et al. Liquefaction of sands during earthquakes[C]//Proc. of Int. Sym. on Soils under Cyclic and Transient Loading, The Cyclic Strain Approach, Swansea,1980.
[90]DeAlba P, Baldwin K, Janoo V. Elastic-wave velocities and liquefaction potential [J]. Journal of Geotechnical Testing:1984,7(2).
[91]徐亦敏,姜朴.在上工测试中共振柱的应用[J].河海大学学报,1991,19(6)：36-41.
[92]徐存森,吴俊璧.用扭转单剪/共振柱仪测定某核电站饱和原状砂的动剪切模量[J].大坝观测与土工测试,1996,20(5)：36-39,50.
[93]王权民,李刚,陈正汉.厦门砂土的动力特性研究[J].岩土力学,2005,26(10)：1628-1632.
[94]蒋阴鲁,舘山腾,山田孝弘,小岛謙一,澤田亮.不整形地盤の液状化对策工実験[C]//土木學會第55回年次学術講演會論文集,束京：丸善(株)出版事業部,2000：Ⅲ-B-204.
[96]日本建投省土木研究所.液化封策工法開發共同研究報告書[R].束京：1997.
[97]Sasaki Y, Taniguchi E. Shaking table tests on gravel drains to prevent liquefaction of sand deposits[J]. Soils and Foundations,1982,22(3):1-14.
[98]Susumu I, Katsuhiko K, Setsuo N, et al. Large scale model tests and analysis of gravel drains[C]//Proceedings of 9th World Conference on Earthquake Engineering, August 2-9,1988, Tokyo-Kyoto, JAPAN:Ⅲ-4-3-14.
[99]Tanaka Y, Kokusho T, Esashi Y. Effects of gravel piles on stabilizing a sand deposit susceptible to liquefaction:Part2. On the designing method of gravel piles with finite permeability[R]//Rep. Cent. Res. Inst. Elec. Pow. Ind,1983.
[100]Miyajima M, Yoshida M, Kitaura M. Small scale tests on countermeasures against liquefaction for pipelines using gravel drain system[C]//U.S.NCEER. Proceedings of the 4th Japan-USA workshop on earthquake resistant design of lifeline facilities and countermeasures for soil liquefaction, Aug,1992, New York, USA, Technical Report NCEER:1-92-0019.
[101]Tokimatsu K, Yoshimi Y. Effects of vertical drains of the bearing capacity of saturated sand during earthquakes[C]//Proceeding of Int. Con. of Engineering for Protection from Natural Disserts, Bangkok,1980:643-655.
[102]王士风.建筑物可液化砂基用砾石排水桩抗震加固的试验研究[D].北京：冶金部研究总院,1984.
[103]景立平,崔杰,李志云,等.粉土液化的小型振动台试验研究[J].地震工程与工程振动,2004,24(3)：145-151.
[104]Yoshimi Y, Tokimatsu K. Settlement of buildings on saturated sand during earthquakes[J]. Soils and Foundations,1977,17(1):23-38.
[105]门福录,崔杰,景立平,等.建筑物饱和砂土地基地震液化判别的简化分析方法[J].水利学报,1998,No.5：33-38.
[106]陈文华,门福录,景立平,等.有建筑物存在的饱和砂土地基液化振动台模拟实验研究[J].地震工程与工程振动,1998,18(4)：54-59.
[107]Sasaki Y, Taniguchi E. Large scale shaking table tests on the effectiveness of gravel drains for liquefiable sand deposits[C]//Cakmak A S, Abdel-Ghaffar A M, Brebbia C A, eds. Proceedings of the conference on soil dynamics and earthquake engineering, Southampton, UK, Rotterdam,1982:843-857.
[108]Igor K, Prevost J H. Dynamic effects in saturated layered soil deposit:centrifuge modeling[J]. Soil Dynamics and Earthquake Engineering,1992,11(8):485-496.
[109]Sekiguchi H, Phillips R. Generation of water waves in a drum centrifuge[C]//Ko, ed. Proceedings of International Conference on Centrifuge 1991, Rotterdam,1991: 343-350.
[110]Scott R S, Richard H L, Mary E H. The influence of high confining stress on the cyclic behaviour of saturated sand[J]. Soil Dynamics and Liquefaction,2000:35-58.
[111]Sekiguchi H, Kita K, Sassa S, et al. Generation of progressive fluid waves in a geo-centrifuge[J]. Geotechnical Testing Journal,1998,21(2):95-101.
[112]閆澍旺,邱长林,孙宝仓,等.波浪作用下海底软黏土力学性状的离心模型试验研究[J].水利学报,1998,No.9：95-101.
[113]Zeng X W. Several important issues related to liquefaction study using centrifuge [J]. Physics and Mechanics of Soil Liquefaction,1999:283-293.
[114]Fujii N. Development of and electromagnetic centrifuge earthquake simulator[C]// Ko, ed. Proceedings of International Conference on Centrifuge 1991, Balkma, Rotterdam,1991:351-353.
[115]Ledbetter R H, Butler G D, Steedman R S. Investigations on the behaviour of liquefying soils[J]. Physics and Mechanics of Soil Liquefaction,1999:295-306.
[116]Ko H Y, Dewoolkar M M. Modelling liquefaction in centrifuge[J]. Physics and Mechanics of Soil Liquefaction,1999:307-322.
[117]Sassa S, Sekiguchi H. Wave-induced liquefaction of beds of sand in a centrifuge [J]. Geotechnique,1999,49(5):621-638.
[118]Fiegel G L, Kutter B L. Liquefaction mechanism for layered soils[J]. Journal of the Geotechnical Engineering Division, ASCE,1994,120(4):737-755.
[119]Miyamoto J, Sassa S, Sekiguchi H. Wave-induced liquefaction and changes in void ratio profile with depth[J]. Physical modeling in geotechnics,2002:259-264.
[120]Mourad Z, Ahmed W E, Zeng X W, et al. Mechanism of liquefaction response in sand-silt dynamic centrifuge tests[J]. Soil Dynamics and Earthquake Engineering, 1999,18(1):71-85.
[121]Madabhushi S P G, Scho field A N. Centrifuge modeling of tower structures on saturated sands subjected to earthquake perturbations[J]. Geotechnique,1993,43(4): 555-565.
[122]Taboada U, Victor M, Dobry R. Centrifuge modeling of earthquake-induced lateral spreading in sand[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1998,124(12):1195-1206.
[123]White R V, lambe P C. Effect of boundary conditions upon centrifuge experiments using ground motion simulation[J]. Geotechnical Testing Journal,1986,9:61-71.
[124]Zeng X W, Schofield A N. Design and performance of an equivalent-shear-beam container for earthquake centrifuge modeling[J]. Geotechnique,1996,46(1):83-102.
[125]Fiegel G L, Hudson M, Idriss I M, et al. Effect of model containers on dynamic soil response[C]//Leung C. F, Lee F. H, Tan S, eds. Proc. of Int. Con. on Centrifuge 1994, Balkema, Rotterdam,1994:145-150.
[126]Madabhushi S P G. Effect of pore fluid in dynamic centrifuge rnodeling[C]//Leung C F, Lee F H, Tan S, eds. Proceedings of International Conference on Centrifuge 1994, Balkema, Rotterdam,1994:127-132.
[127]日本铁道総合技衍研究所.铁道構造物等設計標準·同解說(土構造物)[S].束京：丸善(株)出版事業部,1992.
[128]日本铁道総合技術研究所.铁道構造物等設計標準·同解說(省力轨道土構造物)[S].束京：丸善(株)出版事業部,1999.
[129]日本铁道総合技衍研究所.铁道構造物等設計標準·同解說(抗震設計)[S].東京：丸善(株)出版事業部,1999.
[130]日本铁道総合技衍研究所.搅拌混合基楚(機械搅拌方式)設計·施工の手引き[S].束京：1987.
[132]衡朝阳,何满潮,裘以惠.含黏粒砂土抗液化性能的试验研究[J].工程地质学报,2001,9(4)：339-344.
[133]中铁四院地路处.京沪高速铁路液化土地基加固技术试验研究—路基试验工程设计方案[R].武汉：2004.
[134]GDS Instruments Ltd. GDS软件操作用户手册[M].U.K.：2004.
[135]南京水利科学研究院土工研究所.土工试验技术手册[M].北京：人民交通出版社,2003.
[136]严栋,蒋关鲁,刘先峰,李华明.京沪高速铁路饱和粉土液化特性试验研究[J].岩土力学,2008,29(12)：3337-3341.
[137]Seed H B, Martin P P, Lysmer J. Pore-water pressure changes during soil liquefaction [J]. Journal of the Geotechnical Engineering Division, ASCE,1976,102(GT4): 325-326.
[138]蒋关鲁,张俊兵,李华明.高速铁路液化土地基-路基抗震加固构造：中国,ZL200920176876.6[P].2010-7-21.
[139]日本土質工学会.補强土工法[M].東京：土質工学会,1986.5.
[140]Finn W D L, Fujita N. Piles in liquefiable soils:seismic analysis and design issues[J]. Soil Dynamics and Earthquake Engineering,2002,22(9):731-742.
[141]蒋关鲁,刘先峰,张建文,赵如意.高速铁路液化土地基加固的振动台试验研究[J].西南交通大学学报,2006,41(2)：190-196.
[142]刘先峰,蒋关鲁,张建文.CFG桩加固液化土地基的振动台试验研究[J].路基工程,2006,No.6：54-56.
[143]李华明,蒋关鲁,刘先峰.CFG桩加固饱和粉土地基的动力特性试验研究[J].岩土力学,2010,31(5)：1550-1554.
[144]李华明,蒋关鲁,刘先峰.饱和粉土地基CFG桩加固前后动力特性试验研究[J].铁道建筑,2009,No.6：70-72.
[145]李华明,蒋关鲁,刘先峰.京沪高速铁路饱和粉土液化地基加固效果研究[J].路基工程,2009,No.3：12-13.
[146]Seed H B, Idriss I M. A simplified procedure for evaluation soil liquefaction potential [J]. Journal of the Geotechnical Engineering Division, ASCE,1971,97(2): 201-255.
[147]Barron R A, et al. Consolidation of fine-grained soils by drain wells[R]//Tans. Am. Soc. Civ. Eng., ASCE,1948,113:718-742.
[148]Prater E G, Studer J. Some considerations on the seismic behaviour of rockfill dams[C]//The 13th International Congress on Large Dams, New Delhi, India,1979, Vol.11:1097-1113.
[149]徐志英.地震期孔隙水压力变化估算方法[J].水利学报,1981,No.4：68-72.
[150]殷宗泽.土的沉降与固结[M].北京：中国电力出版社,1998：32-33.
[151]Kramer S. Geotechnical Earthquake Engineering[M]. Prentice-Hall. Inc, U.S.A.: 1996.
[152]Ishibashi I, Zhang X. Unified dynamic shear modulus and damping ratios of sand and clay[J]. Soils and Foundations,1993,33(1):182-191.
[153]DeAlba P, Chan C K, Seed H B. Determination of soil liquefaction characteristics by large-scale laboratory tests[R]//Report EERC, Earthquake Engineering Research Center, University of California, Berkeley,1975:75-14.
[154]Lee K L, Albaisa A. Earthquake induced settlements in saturated sands[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1974:100(GT4).
[155]Youd T L, Idriss I M, Hynes M E, et al. Liquefaction resistance of soils:summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, ASCE,2001:127(10):817-833.
[156]Seed H B, Peacock W H. Test procedure for measuring soil liquefaction characteristics [J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1971,97(SM8): 1099-1119.
[2]中国科技情报研究所.地基的地震效应和砂土液化译文选辑[M].北京：科学技术文献出版社,1978.
[3]陈一全,连峰,付飞营,等.黄河下游冲积粉土地震液化判别研究[J].山东建筑大学学报,2006,21(6)：490-491.
[4]钟龙辉.轻亚粘土地震液化判别方法的分析[J].岩土工程学报,1980,3(3)：.32-36.
[5]王余庆.轻亚粘土地震液化的判别[C]//地基与工业建筑抗震论文集.北京：地震出版社,1984.
[6]Ishihara K. Liquefaction and flow failure during earthquake[J]. Geotechnique,1993, 43(6):351-415.
[7]Seed H B. Design problems in soil liquefaction[J]. Journal of the Geotechnical Engineering Division, ASCE,1987,113(GT8):827-845.
[8]Seed H B, Booker J B. Stabilization of potentially liquefiable sand deposits using gravel drains[J]. Journal of the Geotechnical Engineering Division, ASCE,1977,103(GT7): 757-768.
[9]王晨燕.我国第一个史载文献最详细的8级地震-元朝山西省洪洞赵城地震[J].文史月刊,2010,No.7：10.
[10]师新明.国外地震砂土液化研究[J].铁道工程学报,1990,No.3：148.
[11]王景明.唐山地震的地面破坏效应[J].地震研究,1987,10(4)：451.
[12]刘恢先.唐山大地震震害(一)、(四)[M].北京：地震出版社,1986：339、393.
[13]孙锐,袁晓铭.第11届国际土动力学和地质工程会议及第13届世界地质工程会议砂土液化研究综述[J].世界地震工程,2006,22(1)：16-20.
[14]Casagrande A. Characteristics of cohesionless soils affecting the stability of slope and earth fills [J]. Journal of the Boston Society of Engineerings,1936,23(1):257-276.
[15]Casagrabde A. Liquefaction and cyclic deformation of sands, a critical review[C]// Proc.of 5th Pan-American conf. on Soil Mechanics and Foundation Engineering, Buenosaires:1975.
[16]Castro G. Liquefaction and cyclic mobility of saturated sands[J]. Journal of the Geotechnical Engineering Division, ASCE,1975,101(6):551-569.
[17]马斯洛夫.土力学问题(1954)[M].北京：建筑工程出版社,1959：1-85.
[18]HUANG Wen-xi. Investigation on stability of saturated sand foundation and slope against liquefaction[C]//Proc. of 5th international conf. on soil mechanics and foundation engineering, Paris,1961,Ⅱ:629-631.
[19]Seed H B, Lee K L. Liquefaction of saturated sands during cyclic loading[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1966,92(6):105-134.
[20]Seed H B. Soil liquefaction and cyclic mobility evaluation for level ground during earthquakes[J]. Journal of the Geotechnical Engineering Division, ASCE,1979, 105(2):201-255.
[21]Castro G. Liquefaction of Sands[M]. Cambridge:Harvard University,1969.
[22]Castro G, Seed H B, Keller T O, et al. Steady-state strength analysis of lower San Fernanda dam slide[J]. Journal of the Geotechnical Engineering Division, ASCE,1992, 118(3):406-427.
[23]谢定义.土动力学[M].西安：西安交通大学出版社,1988.
[24]Committee on Soil Mechanics of the Geotechnical Engineering Division. Definition of terms related to liquefaction by the Committee on Soil Mechanics of the Geotechnical Engineering Division[J]. Journal of the Geotechnical Engineering Division, ASCE, 1978,104(GT9):1-10.
[25]赵成刚,尤昌龙.饱和砂上液化与稳态强度[J].上木工程学报,2001,34(3)：90-96.
[26]鲁晓兵.垂直荷载作用下饱和砂土的液化分析[D].北京：中国科学院力学研究所,1999.
[27]汪文韶.土的动力强度和液化特性[M].北京：中国电力出版社,1995.
[28]Kramer S L, Seed H B. Initiation of soil liquefaction under static loading conditions [J]. Journal of Geotechnical Engineering, ASCE,1988,114(4):412-430.
[29]钱家欢.土工原理与计算[M].北京：中国水利水电出版社,1996：524.
[30]张克绪.饱和砂土的液化应力条件[J].地震工程与工程震动,1984,4(1)：100-108.
[31]刘成宇.土力学[M].北京：中国铁道出版社,2000：302-303.
[32]王星华,周海林.砂上液化动稳态强度分析[J].岩石力学与工程学报,2003,22(1)：96-102.
[33]聂守智.在动荷载作用下饱和砂土的液化及其强度[J].岩土工程学报,1980,2(3)：64-73.
[34]陈春霖,张慧明.饱和砂土三轴试验中的若干问题[J].岩土工程学报,2000,22(6)：660-663.
[35]ZHANG H. Steady state behavior of sands and limitations of the triaxial tests [D]. Ottawa:University of Ottawa,1997.
[36]Bishop A W, Green E G. The influence of end restraint on the compression strength of a cohesionless soil[J]. Geotechnique,1965,15(3):243-266.
[37]Roscoe K H, Schofield A N, Wroth C P. Correspondence on "On the yielding of soils" [J]. Geotechnique,1959,9(3):72.
[38]Lade P V. Initiation of static instability in the submarine Nerlerk berm[J]. Canadian Geotechnical Journal,1993,30(6):895-904.
[39]Lade P V. Static instability and liquefaction of loose fine sandy slopes[J]. Journal of Geotechnical Engineering, ASCE,1992,118(1):51-71.
[40]Lade P V, Yamamuro J A. Effects of nonplastic fines on static liquefaction of sands[J]. Canadian Geotechnical Journal,1997,34(6):918-928.
[41]Yamamuro J A, Lade P V. Static liquefaction of very loose sands[J]. Canadian Geo-technical Journal,1997,34(6):905-917.
[42]Seed H B, Tokimatsu K, Harder L F, et al. Influence of SPT procedures in soil liquefaction resistance evaluations[J]. Journal of Geotechnical Engineering, ASCE, 1985,111(12):1425-1445.
[43]Troncoso J H. Failure risks of abandoned tailings dams[C]//International Commission on Large Dams. Proc. Int. Sym. On Safety and rehabilitation of Tailings dams, Paris, 1990:82-89.
[44]Puri V K. Liquefaction behavior and dynamic properties loessial soils[D]. Columbia: University of MissouriRolla,1984.
[45]Puri V K. Liquefaction aspects of loessial soils[R]//EERI. Proc. of 4th US National Conference on Earthquake Engineering,1990,3:755-762.
[46]Sandoval J. Liquefaction and settlement characteristics of silty soils[D]. Columbia: University of MissouriRolla,1989.
[47]Prakash S, Sandoval J. Liquefaction of low plastic silts[J]. Soil Dynamic and Earthquake Engineering,1992,71(7):373-397.
[48]GUO Tian-qiang, Shamsher P. Liquefaction of silts and silt-clay mixtures[J]. Journal of Geotechnical Engineering, ASCE,1999,125(8):706-710.
[49]阮永芬,陈昆梅,韦敏才.粉土地震液化等级评判的人工神经网络技术应用[J],昆明理工大学学报,2000,25(4)：63-65.
[50]牛琪瑛,裘以惠,史美筠.粉土抗液化特性的试验研究[J].太原工业大学学报,1996,27(3)：5-9.
[51]Koester J P. Effects of fines type and content on liquefaction potential of low tomedium plasticity fine-grained soils[C]//Central United States Earthquake Consortium. Proc. of 19th Nat. Earthquake Conf, Tennessee,1993:67-75.
[52]甘霖.粉质壤土动三轴试验分析[C]//栾茂田.第五届全国土动力学学术会议论文集,大连：大连理工出版社,1998：176-180.
[53]Yamamuro J A, Covert K M. Monotonic and cyclic liquefaction of very loose sands with high silt content[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,2001,127(4):314-324.
[54]Polito C P, Martin Ⅱ J R. Effects of nonplastic fines on the liquefaction resistance of sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,2001, 127(5):408-415.
[55]Thevanayagam S, Fiorillo M, Liang J. Effect of non-plastic fines on undrained cyclic strength of silty sands[J]. Soil Dynamics and Liquefaction, ASCE,2000:77-91.
[56]Thevanayagam S. Effect of fines and confining stress on steady state strength of silty sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE,1998, 124(6):479-491.
[57]Thevanayagam S, Mohan S. Intergranular state variables and stress-strain behavior of silty sands[J]. Geotechnique,2000,50(1),1-23.
[58]陈存礼,谢定义.偏应力往返作用下饱和砂上变形特性的试验研究[J].岩石力学与工程学报,2005,24(4)：669-675.
[59]陈存礼,谢定义.球应力往返作用下饱和砂土变形特性的试验研究[J].岩石力学与工程学报,2005,24(3)：513-520.
[60]陈存礼,谢定义.不排水条件下饱和砂土的应力比与应变比之间关系的试验研究[J].陕西水力发电,1999,15(2)：6-9.
[61]孔亮,段建立,郑颖人.慢速往复荷载下饱和砂土变形特性试验研究[J].工程勘察,2001,No.5：1-4.
[62]栾茂田,徐成顺,郭莹,等.静力与动力组合应力条件下饱和松砂变形特性的试验研究[J].土木工程学报,2005,38(3)：81-86.
[63]郭莹,栾茂田,何杨,等.主应力方向循环变化对饱和松砂不排水动力特性的影响[J].岩土工程学报,2005,27(4)：403-409.
[64]谢永涛,张鸿儒.不同路径下饱和砂土的动力特性模型[J].大坝观测与土工测试,2001,25(1)：43-45.
[65]孙锐,袁晓铭.地震荷载下饱和砂土孔压增长时程计算方法[J].地质工程与工程振动,2006,26(3)：261-263.
[66]王星华,周海林.固结比对饱和砂土液化的影响研究[J].中国铁道科学,2001,22(6)：121-126.
[67]周海林,王星华.动三轴实验中的饱和砂土孔隙水压力分析[J].铁道学报,2002, 24(6)：93-98.
[68]于濂洪,王波.饱和粉土振动孔隙水压力的试验研究[J].大连大学学报,1999,20(4)：59-62.
[69]于洪治.饱和粉土振动孔隙水压力发展规律[C]//吴世明.第四届全国土动力学学术会议论文集,杭州：浙江大学出版社,1994：107-110.
[70]冯秀丽,叶银灿,马艳霞,等.动荷载作用下海底粉土的孔压响应及其动强度[J].青岛海洋大学学报,2002,32(3)：429-433.
[71]曹宇春,王天龙.上海粉土液化特性及孔压模型的试验研究[J].上海地质,1998,67(3)：60-64.
[72]陈国兴,刘雪珠.南京粉质黏土与粉砂互层土及粉细砂的振动孔压发展规律研究[J].岩土工程学报,2004,26(1)：79-82.
[73]Alba P A, Chan C K, Seed H B. Sand liquefaction in large-scale simple shear tests [J]. Journal of the Geotechnical Engineering Division, ASCE,1976,102(9):909-927.
[74]左元明,郭家禄,魏汝龙.振动单剪仪的研制和调试[J].岩土工程学报,1980,2(1)：78-86.
[75]魏汝龙,郭家禄,左元明.往复荷载下饱和粉砂土中的孔隙水压力[J].土木工程学报,1983,16(1)：22-32.
[76]Sherif M A, Tsuchiya C, Ishibashi I. Saturation effects on initial soil liquefaction [J]. Journal of the Geotechnical Engineering Division, ASCE,1977,103(8):914-917
[77]Ishibashi I, Sherif M A. Soil liquefaction by torsional simple shear device[J]. Journal of the Geotechnical Engineering Division, ASCE,1974,100(8):871-888
[78]Alarcon-Guzman, Leonards G A, Chameau J L. Undrained monotonic and cyclic strength of sands[J]. Journal of Geotechnical & Geoenvironmental Engineering, ASCE, 1988,114(10):1089-1109.
[79]徐干成,谢定义,郑泽民.饱和砂土振动扭剪孔隙水压力的研究[J].西北水资源与水工程,1992,3(2)：1-11.
[80]Finn W D L, Bhatia S K. Prediction of seismic pore-water pressures[C]//Proceedings of 10th International Conference on Soil Mechanics and Foundation Engineering, Rotterdam,1981,3:201-221.
[81]赵冬.振动扭剪试验中饱和砂的动力特性研究[J].岩土工程学报,1989,11(2)：88-94.
[82]Ishimoto M, Iida K. Determination of elastic constants of soils by means of vibration methods[J]. Bulletin of the Earthquake Research Institute, Tokyo Imperial University, 1937, Vol.15.
[83]Casagrande A, Corso J M, Wilson S D. Report to waterways experiment station on the 1949-1950 program of investigation of effect of long-time loading on the strength of clay and shales at constant water content[R]//Contract Report of U.S. Army Engineer Waterways Experiment Station, Cambridge:Harvard University,1950, No.3-3.
[84]Stevens H W. Suggested method of test for some viscoelastic properties of materials, especially frozen and nonfrozen soils, under vibratory loads[J]. Special Procedures for Testing Soil and Rock for Engineering Purposes,1970, No.6:530-546.
[85]Hardin B O, Drnevich V P. Shear modulus and damping in soil:Measurement and parameter effects[J]. Journal of the Soil Mechanics and Foundations Division, ASCE, 1972,98(6):603-624.
[86]徐瑞旻.共振柱试验程式视窗化之研究[D].台南：国立成功大学,2002.
[87]郭家禄,施萍.饱和砂剪切模量和阻尼比在GZ-1型共振柱仪上的测定[J].大坝观测与土工测试,1985,9(1)：44-49.
[88]姜朴,孙德安.砂土的共振柱试验与液化剪应力[J].水利学报,1987,No.7：68-70.
[89]Yokel F Y, et al. Liquefaction of sands during earthquakes[C]//Proc. of Int. Sym. on Soils under Cyclic and Transient Loading, The Cyclic Strain Approach, Swansea,1980.
[90]DeAlba P, Baldwin K, Janoo V. Elastic-wave velocities and liquefaction potential [J]. Journal of Geotechnical Testing:1984,7(2).
[91]徐亦敏,姜朴.在上工测试中共振柱的应用[J].河海大学学报,1991,19(6)：36-41.
[92]徐存森,吴俊璧.用扭转单剪/共振柱仪测定某核电站饱和原状砂的动剪切模量[J].大坝观测与土工测试,1996,20(5)：36-39,50.
[93]王权民,李刚,陈正汉.厦门砂土的动力特性研究[J].岩土力学,2005,26(10)：1628-1632.
[94]蒋阴鲁,舘山腾,山田孝弘,小岛謙一,澤田亮.不整形地盤の液状化对策工実験[C]//土木學會第55回年次学術講演會論文集,束京：丸善(株)出版事業部,2000：Ⅲ-B-204.
[96]日本建投省土木研究所.液化封策工法開發共同研究報告書[R].束京：1997.
[97]Sasaki Y, Taniguchi E. Shaking table tests on gravel drains to prevent liquefaction of sand deposits[J]. Soils and Foundations,1982,22(3):1-14.
[98]Susumu I, Katsuhiko K, Setsuo N, et al. Large scale model tests and analysis of gravel drains[C]//Proceedings of 9th World Conference on Earthquake Engineering, August 2-9,1988, Tokyo-Kyoto, JAPAN:Ⅲ-4-3-14.
[99]Tanaka Y, Kokusho T, Esashi Y. Effects of gravel piles on stabilizing a sand deposit susceptible to liquefaction:Part2. On the designing method of gravel piles with finite permeability[R]//Rep. Cent. Res. Inst. Elec. Pow. Ind,1983.
[100]Miyajima M, Yoshida M, Kitaura M. Small scale tests on countermeasures against liquefaction for pipelines using gravel drain system[C]//U.S.NCEER. Proceedings of the 4th Japan-USA workshop on earthquake resistant design of lifeline facilities and countermeasures for soil liquefaction, Aug,1992, New York, USA, Technical Report NCEER:1-92-0019.
[101]Tokimatsu K, Yoshimi Y. Effects of vertical drains of the bearing capacity of saturated sand during earthquakes[C]//Proceeding of Int. Con. of Engineering for Protection from Natural Disserts, Bangkok,1980:643-655.
[102]王士风.建筑物可液化砂基用砾石排水桩抗震加固的试验研究[D].北京：冶金部研究总院,1984.
[103]景立平,崔杰,李志云,等.粉土液化的小型振动台试验研究[J].地震工程与工程振动,2004,24(3)：145-151.
[104]Yoshimi Y, Tokimatsu K. Settlement of buildings on saturated sand during earthquakes[J]. Soils and Foundations,1977,17(1):23-38.
[105]门福录,崔杰,景立平,等.建筑物饱和砂土地基地震液化判别的简化分析方法[J].水利学报,1998,No.5：33-38.
[106]陈文华,门福录,景立平,等.有建筑物存在的饱和砂土地基液化振动台模拟实验研究[J].地震工程与工程振动,1998,18(4)：54-59.
[107]Sasaki Y, Taniguchi E. Large scale shaking table tests on the effectiveness of gravel drains for liquefiable sand deposits[C]//Cakmak A S, Abdel-Ghaffar A M, Brebbia C A, eds. Proceedings of the conference on soil dynamics and earthquake engineering, Southampton, UK, Rotterdam,1982:843-857.
[108]Igor K, Prevost J H. Dynamic effects in saturated layered soil deposit:centrifuge modeling[J]. Soil Dynamics and Earthquake Engineering,1992,11(8):485-496.
[109]Sekiguchi H, Phillips R. Generation of water waves in a drum centrifuge[C]//Ko, ed. Proceedings of International Conference on Centrifuge 1991, Rotterdam,1991: 343-350.
[110]Scott R S, Richard H L, Mary E H. The influence of high confining stress on the cyclic behaviour of saturated sand[J]. Soil Dynamics and Liquefaction,2000:35-58.
[111]Sekiguchi H, Kita K, Sassa S, et al. Generation of progressive fluid waves in a geo-centrifuge[J]. Geotechnical Testing Journal,1998,21(2):95-101.
[112]閆澍旺,邱长林,孙宝仓,等.波浪作用下海底软黏土力学性状的离心模型试验研究[J].水利学报,1998,No.9：95-101.
[113]Zeng X W. Several important issues related to liquefaction study using centrifuge [J]. Physics and Mechanics of Soil Liquefaction,1999:283-293.
[114]Fujii N. Development of and electromagnetic centrifuge earthquake simulator[C]// Ko, ed. Proceedings of International Conference on Centrifuge 1991, Balkma, Rotterdam,1991:351-353.
[115]Ledbetter R H, Butler G D, Steedman R S. Investigations on the behaviour of liquefying soils[J]. Physics and Mechanics of Soil Liquefaction,1999:295-306.
[116]Ko H Y, Dewoolkar M M. Modelling liquefaction in centrifuge[J]. Physics and Mechanics of Soil Liquefaction,1999:307-322.
[117]Sassa S, Sekiguchi H. Wave-induced liquefaction of beds of sand in a centrifuge [J]. Geotechnique,1999,49(5):621-638.
[118]Fiegel G L, Kutter B L. Liquefaction mechanism for layered soils[J]. Journal of the Geotechnical Engineering Division, ASCE,1994,120(4):737-755.
[119]Miyamoto J, Sassa S, Sekiguchi H. Wave-induced liquefaction and changes in void ratio profile with depth[J]. Physical modeling in geotechnics,2002:259-264.
[120]Mourad Z, Ahmed W E, Zeng X W, et al. Mechanism of liquefaction response in sand-silt dynamic centrifuge tests[J]. Soil Dynamics and Earthquake Engineering, 1999,18(1):71-85.
[121]Madabhushi S P G, Scho field A N. Centrifuge modeling of tower structures on saturated sands subjected to earthquake perturbations[J]. Geotechnique,1993,43(4): 555-565.
[122]Taboada U, Victor M, Dobry R. Centrifuge modeling of earthquake-induced lateral spreading in sand[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1998,124(12):1195-1206.
[123]White R V, lambe P C. Effect of boundary conditions upon centrifuge experiments using ground motion simulation[J]. Geotechnical Testing Journal,1986,9:61-71.
[124]Zeng X W, Schofield A N. Design and performance of an equivalent-shear-beam container for earthquake centrifuge modeling[J]. Geotechnique,1996,46(1):83-102.
[125]Fiegel G L, Hudson M, Idriss I M, et al. Effect of model containers on dynamic soil response[C]//Leung C. F, Lee F. H, Tan S, eds. Proc. of Int. Con. on Centrifuge 1994, Balkema, Rotterdam,1994:145-150.
[126]Madabhushi S P G. Effect of pore fluid in dynamic centrifuge rnodeling[C]//Leung C F, Lee F H, Tan S, eds. Proceedings of International Conference on Centrifuge 1994, Balkema, Rotterdam,1994:127-132.
[127]日本铁道総合技衍研究所.铁道構造物等設計標準·同解說(土構造物)[S].束京：丸善(株)出版事業部,1992.
[128]日本铁道総合技術研究所.铁道構造物等設計標準·同解說(省力轨道土構造物)[S].束京：丸善(株)出版事業部,1999.
[129]日本铁道総合技衍研究所.铁道構造物等設計標準·同解說(抗震設計)[S].東京：丸善(株)出版事業部,1999.
[130]日本铁道総合技衍研究所.搅拌混合基楚(機械搅拌方式)設計·施工の手引き[S].束京：1987.
[132]衡朝阳,何满潮,裘以惠.含黏粒砂土抗液化性能的试验研究[J].工程地质学报,2001,9(4)：339-344.
[133]中铁四院地路处.京沪高速铁路液化土地基加固技术试验研究—路基试验工程设计方案[R].武汉：2004.
[134]GDS Instruments Ltd. GDS软件操作用户手册[M].U.K.：2004.
[135]南京水利科学研究院土工研究所.土工试验技术手册[M].北京：人民交通出版社,2003.
[136]严栋,蒋关鲁,刘先峰,李华明.京沪高速铁路饱和粉土液化特性试验研究[J].岩土力学,2008,29(12)：3337-3341.
[137]Seed H B, Martin P P, Lysmer J. Pore-water pressure changes during soil liquefaction [J]. Journal of the Geotechnical Engineering Division, ASCE,1976,102(GT4): 325-326.
[138]蒋关鲁,张俊兵,李华明.高速铁路液化土地基-路基抗震加固构造：中国,ZL200920176876.6[P].2010-7-21.
[139]日本土質工学会.補强土工法[M].東京：土質工学会,1986.5.
[140]Finn W D L, Fujita N. Piles in liquefiable soils:seismic analysis and design issues[J]. Soil Dynamics and Earthquake Engineering,2002,22(9):731-742.
[141]蒋关鲁,刘先峰,张建文,赵如意.高速铁路液化土地基加固的振动台试验研究[J].西南交通大学学报,2006,41(2)：190-196.
[142]刘先峰,蒋关鲁,张建文.CFG桩加固液化土地基的振动台试验研究[J].路基工程,2006,No.6：54-56.
[143]李华明,蒋关鲁,刘先峰.CFG桩加固饱和粉土地基的动力特性试验研究[J].岩土力学,2010,31(5)：1550-1554.
[144]李华明,蒋关鲁,刘先峰.饱和粉土地基CFG桩加固前后动力特性试验研究[J].铁道建筑,2009,No.6：70-72.
[145]李华明,蒋关鲁,刘先峰.京沪高速铁路饱和粉土液化地基加固效果研究[J].路基工程,2009,No.3：12-13.
[146]Seed H B, Idriss I M. A simplified procedure for evaluation soil liquefaction potential [J]. Journal of the Geotechnical Engineering Division, ASCE,1971,97(2): 201-255.
[147]Barron R A, et al. Consolidation of fine-grained soils by drain wells[R]//Tans. Am. Soc. Civ. Eng., ASCE,1948,113:718-742.
[148]Prater E G, Studer J. Some considerations on the seismic behaviour of rockfill dams[C]//The 13th International Congress on Large Dams, New Delhi, India,1979, Vol.11:1097-1113.
[149]徐志英.地震期孔隙水压力变化估算方法[J].水利学报,1981,No.4：68-72.
[150]殷宗泽.土的沉降与固结[M].北京：中国电力出版社,1998：32-33.
[151]Kramer S. Geotechnical Earthquake Engineering[M]. Prentice-Hall. Inc, U.S.A.: 1996.
[152]Ishibashi I, Zhang X. Unified dynamic shear modulus and damping ratios of sand and clay[J]. Soils and Foundations,1993,33(1):182-191.
[153]DeAlba P, Chan C K, Seed H B. Determination of soil liquefaction characteristics by large-scale laboratory tests[R]//Report EERC, Earthquake Engineering Research Center, University of California, Berkeley,1975:75-14.
[154]Lee K L, Albaisa A. Earthquake induced settlements in saturated sands[J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1974:100(GT4).
[155]Youd T L, Idriss I M, Hynes M E, et al. Liquefaction resistance of soils:summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, ASCE,2001:127(10):817-833.
[156]Seed H B, Peacock W H. Test procedure for measuring soil liquefaction characteristics [J]. Journal of the Soil Mechanics and Foundations Division, ASCE,1971,97(SM8): 1099-1119.