摘要
我国的高速公路、铁路建设近年来突飞猛进,建设投资不断地增加,规模不断地扩大,随着我国高速公路逐步向中西部地区的延伸,出现了越来越多的高填方路基。与一般的较低路基相比,高填方路基填筑高度大、填筑面积和土石方工程量大、自重大。要求路堤本身具有足够的整体强度和稳定性,并控制总沉降量和沉降速率,如果不能满足使用要求,将严重影响交通安全及运输速度。
对于软土地区的高填方路基,在填筑过程中会产生较大的超孔隙水压力,由于软土的渗透系数较小,造成超孔隙水压力消散速度较慢,土体的有效应力增长缓慢,影响路基变形的稳定性。高填方路基变刚度处理技术中的无砂混凝土小桩后处理阶段,有排水固结以及胶结和竖向增强置换多重作用,适用于处理饱和软土、粉质粘土、粘性土、素填土、杂填土的公路路基。
本文通过总结现有的高填方路基处理方法及其计算理论,就高填方路基变刚度处理技术展开研究:
研究了高填方路基变刚度处理技术的工作机理,认为无砂混凝土小桩后处理阶段可以有效地消散路堤填筑过程中产生的超孔隙水压力。使用有限元程序进行了高填方路基变刚度处理机理的数值模拟,研究了在路基填土过程中路基底部的孔隙水压力变化规律,以及处理过程中的路堤沉降和变形。进行了高填方路基变刚度技术工作性能的数值模拟,对高填方路基变刚度处理不同工况进行了计算,重点分析了关键工况的路基沉降、位移规律,以及粉喷桩和无砂混凝土小桩的应力分布规律。
对高填方路基变刚度处理技术的关键参数进行对比计算,分析了变刚度高填方路基处理适用的土体,对比了进行不同处理方式情况下的高填方路基沉降变形特点,重点分析了不同桩长、桩体模量、桩间距情况下的路基处理效果,就路堤位移、桩体应力、超孔隙水压力等方面进行了研究。
在现有复合地基研究的基础上,探讨了高填方路基变刚度处理技术的设计,并讨论了其关键技术参数的计算方法。
结合工程实测数据,分析了变刚度处理技术对高填方路基的处理效果,为变刚度处理机理的研究提供了一定的数据支持。
根据目前的研究成果,对高填方路基变刚度处理技术的发展前景和尚需进一步研究的课题进行了阐述。
With the fast development of China's freeway and railway constructions in recent years, both construction investment and scale are unceasingly expanding. Along with highway constructions gradually outspreading, there are more and more high-fill embankments in the mid and west area of China. Compared with normal road embankment, high-fill road embankment owns large height, wide fill area, and large quantities of conditions. Then request embankment itself has enough strength and stability, and control of total settlement and sedimentation rate, if cannot meet the demands, will seriously affect traffic safety and transportation speed.
For freeway high-fill embankment in soft soil area, excess pore pressure is created during the fill process, because of the small permeability coefficient, excess pore water pressure dissipate slowly, so as the additional effective soil stress. Then influence the stability of roadbed deformation. The variable stiffness processing technology for high-fill road embankment, which has post treat period using non-sand concrete micro-pile, can speed up drainage ratio and cementing and vertical displacement. The technology can be used in the road embankment of saturated soft soil, silt clay, clay, plain fill, miscellaneous fill.
Based on summarizing the existing high-fill embankment processing method and calculation theory, variable stiffness treatment technology of Embankment treatment is studied:
The mechanism of high-fill embankment variable stiffness technology is studied, and convinced that non-sand pile treatment can dissipate the excess pore pressure creating during the fill process. By using FEM to study the mechanism for high-fill Embankment post treatment, the variation of the excess pore pressure, embankment settlement and deformation with the processing of the fill are calculated and analyzed.
The variable stiffness high-fill Embankment work performance is studied by numerical simulation, different processing conditions are calculated. The key conditions of the embankment settlement, displacement, and the stress distribution regularity of cement-jetted pile and non-sand concrete micro-pile are analyzed.
The technology of variable stiffness processing parameters is analyzed, and the applicability, deformation under different treatment is studied. The embankment behavior is simulated by changing the pile length, pile body modulus, pile spacing. The research concentrates on embankment displacement, pile stress and excess pore pressure, etc.
Based on the researches of composite foundation nowadays, probing into the variable stiffness high-fill road design and calculation method of processing technology, and the key parameters are discussed.
Combined with site measurement data, this paper analyzes the treatment effect of variable stiffness high-fill Embankment post-treatment technology; the research provides data for the mechanism studies.
According to the current research, some advises are discussed for the further research of variable stiffness post-processing high-fill Embankment technology.
引文
[1]王晋明,李国华,孙林.高填方路基沉陷分析及防治措施[J].林业科技,2002,27(1):59~61.
[2]张劲超.高路堤路面水泥稳定层纵向开裂成因及注浆加固处理分析[J].中外公路,2007,27(2):52~54.
[3]聂重军,郑俊杰.高速公路桥头跳车原因分析及防治措施[J].公路,2004(3):109~112.
[4]朱明双,朱向荣,王金昌.桥头软基现浇筒桩处理现场试验分析[J].土木工程学报,2006,39(8):102~106.
[5]马凡.CFG桩复合地基降低高填方路基沉降的计算及应用.公路,2006(2):84~86.
[6]张洁,王攀.预应力混凝土管桩在深厚软土路基中的应用[J].路基工程,2006(4)56~58.
[7]程贤志,张广明.不同加固方案在软土路基处治中的应用效果比较[J].公路,2007(7):113~115.
[8]杨卫东,朱立增.堆载预压处理高速公路高填土路基技术分析[J].公路交通技术,2006(4):1~5.
[9]曹永琅,丛建,吴晓峰.高速公路超软土地基的真空预压加固研究[J].岩土力学,2003,24(5):771~775.
[10]管殿聆,阎万里.冲击式压路机在湿陷性黄土高填方重载路基上的应用[J].铁道标准设计,2001,21(11):24~25.
[11]黄生根,张希浩,曹辉,彭从文.地基处理与基坑支护工程[M].武汉:中国地质大学出版社,2004.
[12]任福松,杜卫乾.PHC管桩在软基处理中的应用[J].交通标准化,2007(11):48~52.
[13]王斌,徐泽中.预应力管桩在高速公路拼接工程软基处理中的设计方法[J].公路,2004(2):84~88.
[14]马凡.CFG桩复合地基降低高填方路基沉降的计算及应用[J].公路,2006(2):84~86.
[15]张洁,王攀.预应力混凝土管桩在深厚软土路基中的应用[J].路基工程,2006(4)56~58.
[16]刘景政、杨素春、钟冬波.地基处理与实例分析[M].北京:中国建筑工业出版社,1998.
[17]郑俊杰,刘志刚,吴世明.石灰桩复合地基固结分析[J].华中理工大学学报,2000,28(5):111~113.
[18]李明杰.李鹏,靳明.高填方路堤复合地基处治研究[J].中外公路,2005,25(3)21~23.
[19]程贤志,张广明.不同加固方案在软土路基处治中的应用效果比较[J].公路,2007(7):113~115.
[20]冯伟凯,眭爱宏,陈振国.高填方车站大面积软土地基整治技术[J].路基工程,铁道标准设计,2003(增刊):184~186.
[21]李道生.高填方地段强夯处理湿陷性黄土夯击参数的选择[J].路基工程,2005(1)25~28.
[22]蔡业青,刘朝权,舒翔.钢花管注浆加固山区高填土路基、台背工艺探讨[J].中外公路,2006,26(3):48~51.
[23]王安舜,李存良,胡琴.堆载预压在高填方施工中的应用[J].西部探矿工程,2005(2):32~33.
[24]杨卫东,朱立增.堆载预压处理高速公路高填土路基技术分析[J].公路交通技术,2006(4):1~5.
[25]V. Tandjiria, B. K. Lowb. C.l. Teh. The Effect of reinforcement force distribution on stability of embankments [J]. Geotextiles and Geomembranes,2002 (20):423~443.
[26]Dennes. T. Bergadoa, Pham V. Longb, B. R. Srinivasa Murthy. A case study of geotextile-reinforced embankment on soft ground[J]. Geotextiles and Geomembranes,2002, 20:343~365.
[27]Jose Leitao Borges, Antonio Silva Cardoso. Overall stability of geosynthetic-reinforced embankments on soft soils[J]. Geotextiles and Geomembranes,2002,20:395~421.
[28]Sean D. Hinchberger, R. Kerry Rowe. Geosynthetic reinforced embankments on soft clay foundations:predicting reinforcement strains at failure[J]. Geotextiles and Geomembranes 2003,21,151~175.
[29]B. S. Bakir, E. Akis. Analysis of a highway embankment failure associated with the 1999 Duzce, Turkey earthquake[J]. Soil Dynamics and Earthquake Engineering,2005,25, 251-260.
[30]A. K. Sinha, Vasant G. Havanagi, Sudhir Mathur. Inflection point method for predicting settlement of PVD improved soft clay under embankments[J]. Geotextiles and Geomembranes,2007,25:336~345.
[31]Allen Lunzhu Li, R. Kerry Rowe. Effects of viscous behavior of geosynthetic reinforcement and foundation soils on the performance of reinforced embankments[J]. Geotextiles and Geomembranes,2008,26:317~334.
[32]Dennes T. Bergado, Chairat Teerawattanasuk.2D and 3D numerical simulations of reinforced embankments on soft ground[J]. Geotextiles and Geomembranes,2008,26:39~ 55.
[33]T. Tanchaisawat, D. T. Bergado, P. Voottipruex. Numerical simulation and sensitivity analyses of full-scale test embankment with reinforced lightweight geomaterials on soft Bangkok clay [J]. Geotextiles and Geomembranes,2008,26:498~511.
[34]K. ADALIER, A. PAMUK, T. F. ZIMMIE. Earthquake retrofit of highway/railway embankments by sheet-pile walls[J]. Geotechnical and Geological Engineering,2004,22: 73~88.
[35]S. Murugesan, K. Rajagopal. Geosynthetic-encased stone columns:Numerical evaluation[J]. Geotextiles and Geomembranes 2006,24:349~358.
[36]H. G. Poulos, F. ASCE. Design Charts for Piles Supporting Embankments on Soft Clay[J]. Journal of Geotechnical and Geoenvironmental Engineering,2007,133 (5) 493~501.
[37]Sari W. Abusharar, Jun-Jie Zheng, Bao-Guo Chen, Jian-Hua Yin. A simplified method for analysis of a piled embankment reinforced with geosynthetics[J]. Geotextiles and Geomembranes,2009,27:39~52.
[38]Sari W. Abusharar, Jun-Jie Zheng, Bao-Guo Chen. Finite element modeling of the consolidation behavior of multi-column supported road embankment[J]. Computers and Geotechnics,2009,36:676~685.
[39]J. S. Sharma, M. D. Bolton. Centrifugal and numerical modelling of reinforced embankments on soft clay installed with wick drains[J]. Geotextiles and Geomembranes,2001,19:23~ 44.
[40]Jose Leitao Borges. Three-dimensional analysis of embankments on soft soils incorporating vertical drains by finite element method[J]. Computers and Geotechnics,2004,31:665~ 676.
[41]R. Kerry Rowe, C. Taechakumthorn. Combined effect of PVDs and reinforcement on embankments over rate-sensitive soils[J]. Geotextiles and Geomembranes,2008,26:239~ 249.
[42]Tuan Anh Tran, Toshiyuki Mitachi. Equivalent plane strain modeling of vertical drains in soft ground under embankment combined with vacuum preloading[J]. Computers and Geotechnics,2008,35:655~672.
[43]Abdulazim Yildiz. Numerical analyses of embankments on PVD improved soft clays[J]. Advances in Engineering Software,2009,40:1047~1055.
[44]童怀峰.高填方路基后处理机理及优化设计[D].郑州:郑州大学土木工程学院,2005.
[45]郭院成,周同和.高速公路高填方软基后处理机理与实践研究[J].哈尔滨建筑大学学报,2002,35(6):116~119.
[46]郭院成,张浩华,周同和.高速公路高填方软基处理方法的对比分析[J].郑州大学学报(工学版),2002,23(2):31~33.
[47]郭院成,张浩华,张军.软土高填方路基后处理方案的优化设计[J].河南科学,2003,21(5):640~643.
[48]张浩华.软土高填方路基后处理技术及工程应用研究[D].郑州:郑州大学土木工程学院,2004.
[49]刘海涛.黄土地区桥头跳车处理新方法研究[D].郑州:郑州大学土木工程学院.2004
[50]童怀峰,杨淑慧,郭院成.高填方路基基于变形控制的后处理优化设计[J].河南科学,2005,23(6):870~873.
[51]童怀峰,郭院成,张浩华.无砂混凝土小桩后处理高填方软基的固结过程分析[J].河南科学,2005,23(5):66~69.
[52]童怀峰,郭院成.无砂混凝土小桩后处理技术在软土地基的应用[J].路基工程,2006(6):64~65.
[53]应荣华,郑健龙.老路拓宽沉降规律ANSYS有限元分析[J].公路,2006(4):140~143.
[54]肖伟,王建西,马斌.京津城际永乐站CFG桩复合地基沉降有限元分析[J].铁道建筑,2007(7):75~77.
[55]王秀格,乔兰,于德水.强夯法处理湿陷性黄土路基效果的数值分析[J].施工技术,2007,36(增刊):374~378.
[56]孙献国.粉喷桩与土工格栅联合加固技术的数值模拟分析研究[J].公路交通科技,2004(5):47~49.
[57]陶连金,张印涛,邹祖银等.黄土加筋路堤的数值模拟及性能分析[J].公路交通科技,2006,23(12):32~36.
[58]蒋鑫,凌建明.软土地区桩柱式路基力学行为的数值模拟[J].交通运输工程学报,2007,7(6):70~75.
[59]马南飞.高速公路软土路基沉降规律监测及FLAC模拟[J].西安建筑科技大学学报,2007,27(2):251~254.
[60]程栋栋,闫澍旺,侯晋芳等.桩与土工格栅联合作用对高速公路路堤地基承载力影响的有限元分析[J].岩士力学,2007,28(增刊):886~890.
[61]俞永华,谢永利,杨晓华等.土工格室柔性搭板处治的路桥过渡段差异沉降三维数值分析[J].中国公路学报,2007,20(4):12~18.
[62]谢永利,俞永华,杨晓华.土工格室在处治路基不均匀沉降中的应用研究[J].中国公路学报,2004,17(4):7~10.
[63]孙吉主,高晖.ABAQUS在软基固结过程分析中的应用[J].岩土力学,2007,28(增刊):919~922.
[64]段仲沅,甄精莲,贾瑞晨等.基于ABAQUS预测某深基坑支护结构变形及其加固措施[J].施工技术,2007,36(11):60~62.
[65]年廷凯,栾茂田,蒋景彩.基于强度折减弹塑性有限元法的抗滑桩加固边坡稳定性分析[J].岩土力学,2007,28(增刊):558~562.
[66]雷学文,陈凯杰.桩-网复合地基承载及变形特性的有限元分析[J].岩土力学,2007,28(增刊):819~822.
[67]刘金砺,迟铃泉.桩土变形计算模型和变刚度调平设计[J].岩土工程学报,2000,22(2):151~157.
[68]陈龙珠,梁发云.变刚度复合地基处理的有限元分析[J].工业建筑,2003,33(11)1~4.
[69]乔京生,步启军,马卫华等.变刚度复合地基的可行性研究[J].铁道建筑,2006(5):49~51.
[70]乔京生,周红星,袁则循.变刚度复合地基力学性状的模型试验研究[J].西安建筑科技大学学报(自然科学版),2009,39(4):479~483.
[71]张武,高文生.变刚度布桩复合地基模型试验研究[J].岩土工程学报,2009,31(6):905~910.
[72]雷金波,向东德,姜弘道.柔性基础下复合地基研究现状分析[J].金属矿山,2005,345(3):49~51.
[73]鲁绪文.路堤荷载下长短桩复合地基加固深厚软土路基的试验与研究[D].南京:南京水利科学研究院,2007.
[74]范跃武,周同和,范永丰.“柔性基础”刚性桩复合地基试验分析与变形计算[J].建筑结构学报,2007,28(6):203~209.
[75]杨庆光,刘杰,张可能,何杰.深厚软土中水泥土长短桩复合地基承载特性试验[J].中国公路学报,2008,21(3):19~23.
[76]郭院成,李明宇.长短桩复合地基桩土应力比的力学计算方法[J].公路交通科技,2009,26(2):37~41.
[77]凌华才,鄂海清,李勇泉等.高速公路扩建工程中长短桩复合地基加固软基的数值分析[J].中外公路,2009,29(4):31~34.
[78]童怀峰.高填方路基加宽后处理技术及变形性状研究[D].郑州:郑州大学土木工程学院,2008.
[79]胡中雄.土力学与环境土工学[M].上海:同济大学出版社,1997.
[80]刘展.ABAQUS6.6基础教程与实例详解[M].北京:中国水利水电出版社,2008.
[81]石亦平,周玉蓉.ABAQUS有限元分析实例详解[M].北京:机械工业出版社,2009.
[82]庄茁,曲小川,廖剑辉等.基于ABAQUS的有限元分析和应用[M].北京:清华大学出版社,2009.
[83]廖公云,黄晓明.ABQUS有限元软件在道路工程中的应用[M].南京:东南大学出版社,2008.
[84]费康,张建伟.ABAQUS在岩土工程中的应用[M].北京:中国水利水电出版社,2010.
[85]曹金凤,石亦平.ABAQUS有限元分析常见问题解答[M].北京:机械工业出版社,2009.
[86]地基处理技术规范(JGJ79-2002)[S].北京:中国建筑工业出版社,2002.
[87]黄生文.公路工程地基处理手册[M].北京:人民交通出版社,2005.
[88]Jie Huang, Jie Han.3D coupled mechanical and hydraulic modeling of a geosynthetic-reinforced deep mixed column-supported embankment[J]. Geotextiles and Geomembranes, 2009,27:272-280.
[89]李彰明.软土地基加固的理论、设计与施工[M].北京:中国电力出版社,2006.
[90]投石压浆无砂砼小桩加固地基技术规程(ATQB02-2006)[S].郑州:河南安泰科技有限公司,2006.
[91]王丽艳,袁新明.微型桩复合地基沉降和动力特性研究[J].水利学报,2005,36(12):1492~1497.