桩—网复合地基变形性状和桩土应力比研究
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摘要
桩-网复合地基适用于软土地基和路基的处理,其特点是“桩-网-土”三者的协同工作,在网、桩和土变形协同作用下,桩土荷载分担比发生变化。桩-网复合地基具有沉降变形小、施工快、工后沉降易于控制、稳定性高、不需预压期、工期短、施工方便等优点。在天然地基上,通过科学合理的设计桩-网复合地基可以较多的减少用桩的数量进而降低工程造价实现良好的经济效益。因此对桩-网复合地基的工作机理进行研究是十分必要的。
论文首先在总结前人研究成果的基础上分析了桩-网复合地基的工作机理,以及土工合成材料的加固机理。然后,本文叙述了土拱理论和薄板变形理论。在桩-网复合地基中,基于土拱理论、薄板变形理论和Winkler弹性地基理论,提出了桩-网复合地基工后沉降计算方法和桩土应力比计算方法,由于该计算模型考虑了桩-网复合地基各组成部分之间的相互作用,能够更准确地反映出桩-网复合地基的工作机理,同时克服了传统算法中“两者不能同时未知”的缺陷,并通过工程算例验证了本文方法的正确性,对于实际工程的应用提供一定的理论依据。
利用有限元软件对桩-网复合地基进行了模拟。分析了桩体、土体、桩间距、桩径等参数变化对桩-网复合地基沉降的影响,进一步分析了桩-网复合地基的工作性状。论文所得主要结论如下:
(1)土工格栅的设置能有效地减小竖向沉降,土工格栅的设置更有效地限制路堤的侧向变形。
(2)桩-网复合地基最大沉降量发生在两桩中心顶部。最大沉降量随着荷载的增加而增加。
(3)最大沉降量随土模量的增大而减小,减小幅度较大。
(4)沉降值相同时,桩-网复合地基比普通复合地基桩间距明显要大。验证了疏桩理论的设计思想。
Pile-net composite foundation is especially suited for soft foundation treatment, its characteristics is that pile and soil share the loads with the cooperation of piles, soil and net. It has many advantages, such as small settlement, ease controlled post-construction, high stability, no precompression, shorten construction, and so on. We can cut down the number of piles and construct cost, on the natural foundation, by scientific and rational design, which can accomplish projects with thetremendous economy benefit.
At the beginning of the thesis, some conclusions on pile-net composite foundation are provided. Working mechanism of pile-net composite foundation and reinforcement mechanism of geotechnical synthetic materials are analysised.There are also a short introduction on the soil arch theory and deformation plate theory .Based on the Soil arch theory, Deformation plate theory and Winkler model, the method is proposed for calculating residual settlement and pile-soil stress ratio of pile - net composite foundation. Because of considering the interaction of the various components of the pile - net composite foundation, the theoretical model shows the working mechanism of the pile - net composite foundation more accurately and overcame the shortcomings of traditional methods. At last, the model was verified by an engineering example and provided the basis for the practical engineering.
And then pile - net composite foundation are simulated using finite element software. From the results of simulation, we get to know some rules about the pile - net composite foundation. Here are some results :
(1) The vertical settlement and lateral deformation are decreased effectively by setting the geotechnical grille.
(2) The maximum settlement of pile - net composite foundation appears at the top of center between two piles. The maximum settlement of pile - net composite foundation increases when the load increases.
(3) The maximum settlement of pile - net composite reduces substantially when the soil modularincreases.
(4) With the same settlement , the pile distance of pile - net composite foundation is longer than normal composite foundation’s .
论文首先在总结前人研究成果的基础上分析了桩-网复合地基的工作机理,以及土工合成材料的加固机理。然后,本文叙述了土拱理论和薄板变形理论。在桩-网复合地基中,基于土拱理论、薄板变形理论和Winkler弹性地基理论,提出了桩-网复合地基工后沉降计算方法和桩土应力比计算方法,由于该计算模型考虑了桩-网复合地基各组成部分之间的相互作用,能够更准确地反映出桩-网复合地基的工作机理,同时克服了传统算法中“两者不能同时未知”的缺陷,并通过工程算例验证了本文方法的正确性,对于实际工程的应用提供一定的理论依据。
利用有限元软件对桩-网复合地基进行了模拟。分析了桩体、土体、桩间距、桩径等参数变化对桩-网复合地基沉降的影响,进一步分析了桩-网复合地基的工作性状。论文所得主要结论如下:
(1)土工格栅的设置能有效地减小竖向沉降,土工格栅的设置更有效地限制路堤的侧向变形。
(2)桩-网复合地基最大沉降量发生在两桩中心顶部。最大沉降量随着荷载的增加而增加。
(3)最大沉降量随土模量的增大而减小,减小幅度较大。
(4)沉降值相同时,桩-网复合地基比普通复合地基桩间距明显要大。验证了疏桩理论的设计思想。
Pile-net composite foundation is especially suited for soft foundation treatment, its characteristics is that pile and soil share the loads with the cooperation of piles, soil and net. It has many advantages, such as small settlement, ease controlled post-construction, high stability, no precompression, shorten construction, and so on. We can cut down the number of piles and construct cost, on the natural foundation, by scientific and rational design, which can accomplish projects with thetremendous economy benefit.
At the beginning of the thesis, some conclusions on pile-net composite foundation are provided. Working mechanism of pile-net composite foundation and reinforcement mechanism of geotechnical synthetic materials are analysised.There are also a short introduction on the soil arch theory and deformation plate theory .Based on the Soil arch theory, Deformation plate theory and Winkler model, the method is proposed for calculating residual settlement and pile-soil stress ratio of pile - net composite foundation. Because of considering the interaction of the various components of the pile - net composite foundation, the theoretical model shows the working mechanism of the pile - net composite foundation more accurately and overcame the shortcomings of traditional methods. At last, the model was verified by an engineering example and provided the basis for the practical engineering.
And then pile - net composite foundation are simulated using finite element software. From the results of simulation, we get to know some rules about the pile - net composite foundation. Here are some results :
(1) The vertical settlement and lateral deformation are decreased effectively by setting the geotechnical grille.
(2) The maximum settlement of pile - net composite foundation appears at the top of center between two piles. The maximum settlement of pile - net composite foundation increases when the load increases.
(3) The maximum settlement of pile - net composite reduces substantially when the soil modularincreases.
(4) With the same settlement , the pile distance of pile - net composite foundation is longer than normal composite foundation’s .
引文
[1]龚晓南.复合地基理论及工程应用[M].杭州:中国建筑工业出版社,2002.
[2]饶为国.桩网复合地基原理及实践[M].中国水利水电出版社,2004.
[3]陈凯杰.桩-网复合地基工作性状的研究[D],2006
[4]杨明辉,赵明华,吴亚中.基于正交理论的土工格栅垫层碎石桩复合地基优化设计[J].公路,2004.
[5]铁路地质和路基工程科技信息中心.粉喷桩的工程特性与设计计算方法研究专辑.铁路地质与路基,2000(1)
[6]饶为国:桩-网复合地基工后沉降的三点推算法[J]岩土工程界,2001.
[7]王钊、王协群.土工合成材料加筋地基设计中的几个问题.岩土工程学报,2000.
[8] LOVE J P,BURDHJ, MILLIGANGWE, et al·Analyticand Model Studies of Reinforcement of a Layer of GranularFon a Soft Clay subgrade [J].Canadian Geotechnical Journa 1987 ,24 (3):611-622.
[9]王亚玲,周玉利。土工格栅加筋半刚性基层材料的抗弯拉强度试验[J].长安大学学报;自然科学版,2006,26(5):26-29.
[10]陈艳平,赵明华,陈昌富,等。土工格室碎石垫层-碎石桩复合地基相似模型试验[J].中国公路学报,2006,19(1):17-22.
[11]杨晓华,戴铁丁,许新桩。土工格室在铁路软弱基床加固中的应用[J].交通运输工程学报,2005,5(2):42-46.
[12]周志刚,郑健龙,李强,土工加筋材料处治填挖交界路基非均匀沉降设计方法研究[J].中国公路学报,2003,16(1):27-31.
[13] Low B K ,et al. Slip circle analysis of reinforced embankments on soft ground. Geotextiles and Geomembranes. 1990,9(2):165-181.
[14]土工合成材料工程应用手册编委。土工合成材料工程应用手册。北京:中国建筑工业出版社,1994.
[15] Kaniraj S R,et al. Reinforcement force in embankment on soft soils. In : Proc of the Inter Sym on Earth Reinforcement Practice, Japan,1992.245-250
[16]王凤池,朱浮生,石刚,层状土中桩体复合地基载荷沉降关系[J].辽宁工程技术大学学报,2004,23(1):49-52.
[17]铁道部第四勘察设计院.粉喷桩得工程特性与实用设计计算方法[J].土工基础(增刊),1999.
[18]李培全.深层搅拌桩复合地基荷载试验问题得探讨[J].工程质量,2001,9:23～24.
[19]肖溟等深层搅拌桩复合地基可靠度分析[J].浙江大学学报,2000,4:351～354.
[20]洪昌华等.深层搅拌桩复合地基的概率分析[J]岩土工程学报,2000,3:279～283.
[21]何胜辉等.深层搅拌桩复合地基的优化设计与应用实例[J].广东土木与建筑,2002,8,13～15.
[22]谢飞胜等.粉喷桩复合地基承载特性试验研究[J]长沙铁道学院学报,2000,4:66～69.
[23]李化然.水泥粉喷桩基设计[J].江苏煤炭,1999,4:29～30.
[24]雷学文,谭峰屹.粉喷桩单桩复合地基承载特性的有限元分析[J].岩土力学,2003,(1):526～528.
[25]龚晓南。复合地基理论及工程应用[M].北京:中国建筑工业出版社,2002:13-14.
[26]陈湘兴,闫雪峰。形成复合地基的条件[J].建筑科学,2001,17(2):5-13.
[27]国家行业标准。建筑桩基技术规范(JGJ94-94)[S].北京:中国建筑工业出版社,1994:5-80。
[28]阎明礼,张东刚。CFG桩复合地基处理技术及工程实践。北京:中国水利水电出版社,2001.
[29]刘景政.地基处理与实例分析。北京:机械工业出版社。2000
[30]叶观宝,叶书麟。地基加固新技术。北京:机械工业出版社,1999
[31]沙祥林,地基处理方法[P].中国专利:ZL 94 1 02594.2 1994-03-16。
[32]周德泉,张可能,刘宏利。组合桩型复合地基计算与应用分析[J].岩土力学,2004(9)。
[33]周德泉,张可能,刘宏利。组合桩型复合地基桩、土受力特性的试验对比与分析[J].岩石力学与工程学报,2005(5)。
[34]孙宏林,王祥,李丹.土工材料与高速铁路路基工后沉降控制[J].铁道勘察;2005.1:36~41。
[35]蒋关鲁詹永祥等.无碴轨道桩板结构路基设计理论及计算理论的探讨[A].武汉:长江出版社,2005:398~401。
[36] Jones C J,Lawson C R, Ayres D J. Geotextile reinforced piled embankment[A].Geotextiles, Geomembrances and Relate Produces[C].Balkema,1990.155-159.
[37] Han J,Akins K.Use of geogrid-reinforce and pile-supported earth structures[A].Proceeding of International Deep Foundation Congress[C]Frlando,Fl,002.668-679.
[38]张明等桩-网复合路基变形机理的数值分析[J].华东公路2008
[39]芮瑞,夏元友桩–网复合地基与桩承式路堤的对比数值模拟[J] .岩土工程学报2007
[40]吕关明.浅谈深层水泥搅拌桩.科学技术与工程20055(12):845一84
[41]龚晓南.形成竖向增强体复合地基的条件[J].地基处理,1995.9.
[42]吴东云.水泥土桩复合地基中合理设置垫层的探讨[J].建筑技术开发,2001,28(2):12-13.
[43]琚旭光等.土工合成材料加筋垫层作地基处理的工程实践[J].煤矿开采,2001,(47):80-82.
[44]王军.水泥土搅拌桩中垫层设置的试验研究[J].工程建设与设计,2004,(1):40-42.
[45]林晓玲,周连明,吴建东等.土工织物加筋垫层的应用研究[J].岩土力学,2000,21(3):252-255.
[46]李小青,潘鸿宝.复合地基柔性垫层作用分析[J].探矿工程,2001,(3):6-8.
[47]刘杰,张可能.复合地基中垫层作用机理[J].中南工业大学学报,2001,32(6):568-572.
[48] Terzaghi K.Theoretical soil mechanics[M]. New YorkJohn Wiley&Son, 1943.
[49]贾海莉,王成华,李江洪.关于土拱效应的几个问题[J].西南交通大学学报,2003,38(4):398一402.
[50]肖宏.高速铁路无碴轨道桩网结构路基研究[D].成都:西南交通大学.2007
[51]饶为国,江辉煌,侯庆华.桩-网复合地基工后沉降的薄板理论解[J]水利学报,2002
[52]龚晓南.21世纪岩土工程发展展望[J].岩土工程学报,2000,22 (2):238~242.
[53]饶为国等.桩-网复合地基工后沉降的薄板变形模拟[J].水利学报,2002,№.4
[2]饶为国.桩网复合地基原理及实践[M].中国水利水电出版社,2004.
[3]陈凯杰.桩-网复合地基工作性状的研究[D],2006
[4]杨明辉,赵明华,吴亚中.基于正交理论的土工格栅垫层碎石桩复合地基优化设计[J].公路,2004.
[5]铁路地质和路基工程科技信息中心.粉喷桩的工程特性与设计计算方法研究专辑.铁路地质与路基,2000(1)
[6]饶为国:桩-网复合地基工后沉降的三点推算法[J]岩土工程界,2001.
[7]王钊、王协群.土工合成材料加筋地基设计中的几个问题.岩土工程学报,2000.
[8] LOVE J P,BURDHJ, MILLIGANGWE, et al·Analyticand Model Studies of Reinforcement of a Layer of GranularFon a Soft Clay subgrade [J].Canadian Geotechnical Journa 1987 ,24 (3):611-622.
[9]王亚玲,周玉利。土工格栅加筋半刚性基层材料的抗弯拉强度试验[J].长安大学学报;自然科学版,2006,26(5):26-29.
[10]陈艳平,赵明华,陈昌富,等。土工格室碎石垫层-碎石桩复合地基相似模型试验[J].中国公路学报,2006,19(1):17-22.
[11]杨晓华,戴铁丁,许新桩。土工格室在铁路软弱基床加固中的应用[J].交通运输工程学报,2005,5(2):42-46.
[12]周志刚,郑健龙,李强,土工加筋材料处治填挖交界路基非均匀沉降设计方法研究[J].中国公路学报,2003,16(1):27-31.
[13] Low B K ,et al. Slip circle analysis of reinforced embankments on soft ground. Geotextiles and Geomembranes. 1990,9(2):165-181.
[14]土工合成材料工程应用手册编委。土工合成材料工程应用手册。北京:中国建筑工业出版社,1994.
[15] Kaniraj S R,et al. Reinforcement force in embankment on soft soils. In : Proc of the Inter Sym on Earth Reinforcement Practice, Japan,1992.245-250
[16]王凤池,朱浮生,石刚,层状土中桩体复合地基载荷沉降关系[J].辽宁工程技术大学学报,2004,23(1):49-52.
[17]铁道部第四勘察设计院.粉喷桩得工程特性与实用设计计算方法[J].土工基础(增刊),1999.
[18]李培全.深层搅拌桩复合地基荷载试验问题得探讨[J].工程质量,2001,9:23～24.
[19]肖溟等深层搅拌桩复合地基可靠度分析[J].浙江大学学报,2000,4:351～354.
[20]洪昌华等.深层搅拌桩复合地基的概率分析[J]岩土工程学报,2000,3:279～283.
[21]何胜辉等.深层搅拌桩复合地基的优化设计与应用实例[J].广东土木与建筑,2002,8,13～15.
[22]谢飞胜等.粉喷桩复合地基承载特性试验研究[J]长沙铁道学院学报,2000,4:66～69.
[23]李化然.水泥粉喷桩基设计[J].江苏煤炭,1999,4:29～30.
[24]雷学文,谭峰屹.粉喷桩单桩复合地基承载特性的有限元分析[J].岩土力学,2003,(1):526～528.
[25]龚晓南。复合地基理论及工程应用[M].北京:中国建筑工业出版社,2002:13-14.
[26]陈湘兴,闫雪峰。形成复合地基的条件[J].建筑科学,2001,17(2):5-13.
[27]国家行业标准。建筑桩基技术规范(JGJ94-94)[S].北京:中国建筑工业出版社,1994:5-80。
[28]阎明礼,张东刚。CFG桩复合地基处理技术及工程实践。北京:中国水利水电出版社,2001.
[29]刘景政.地基处理与实例分析。北京:机械工业出版社。2000
[30]叶观宝,叶书麟。地基加固新技术。北京:机械工业出版社,1999
[31]沙祥林,地基处理方法[P].中国专利:ZL 94 1 02594.2 1994-03-16。
[32]周德泉,张可能,刘宏利。组合桩型复合地基计算与应用分析[J].岩土力学,2004(9)。
[33]周德泉,张可能,刘宏利。组合桩型复合地基桩、土受力特性的试验对比与分析[J].岩石力学与工程学报,2005(5)。
[34]孙宏林,王祥,李丹.土工材料与高速铁路路基工后沉降控制[J].铁道勘察;2005.1:36~41。
[35]蒋关鲁詹永祥等.无碴轨道桩板结构路基设计理论及计算理论的探讨[A].武汉:长江出版社,2005:398~401。
[36] Jones C J,Lawson C R, Ayres D J. Geotextile reinforced piled embankment[A].Geotextiles, Geomembrances and Relate Produces[C].Balkema,1990.155-159.
[37] Han J,Akins K.Use of geogrid-reinforce and pile-supported earth structures[A].Proceeding of International Deep Foundation Congress[C]Frlando,Fl,002.668-679.
[38]张明等桩-网复合路基变形机理的数值分析[J].华东公路2008
[39]芮瑞,夏元友桩–网复合地基与桩承式路堤的对比数值模拟[J] .岩土工程学报2007
[40]吕关明.浅谈深层水泥搅拌桩.科学技术与工程20055(12):845一84
[41]龚晓南.形成竖向增强体复合地基的条件[J].地基处理,1995.9.
[42]吴东云.水泥土桩复合地基中合理设置垫层的探讨[J].建筑技术开发,2001,28(2):12-13.
[43]琚旭光等.土工合成材料加筋垫层作地基处理的工程实践[J].煤矿开采,2001,(47):80-82.
[44]王军.水泥土搅拌桩中垫层设置的试验研究[J].工程建设与设计,2004,(1):40-42.
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