夯扩CFG桩受力特性的三维数值分析
|
摘要
CFG桩复合地基自从1988年立项研究以来,由于该项技术在施工工艺上具有施工速度快、工期短、质量容易控制、工程造价低等特点,经过二十年的工程实践已经获得工程界的一致认可,并被广泛的应用于地基处理。
本文结合南充市川北医学院住院楼的CFG桩复合地基处理工程,利用数值模拟和多元统计的方法对夯扩CFG的受力特性进行了探讨和研究。分析采用的方法是先对实验数据进行分析,然后在此基础上建立施工场地的三维数值模型,利用数值分析的方法分析各种因数对夯扩CFG桩受力特性的影响,之后再以数值分析的数据采用超趋势面的分析方法研究多个因素同时变化对夯扩CFG桩承载特性的影响。
首先,通过现场实验数据对夯扩CFG复合地基桩的轴力传递和桩土荷载分担比进行了分析,选取了短期观测实验的五根桩进行分析,通过对桩土荷载分担比的线形拟合发现,除其中一根桩由于初始桩土荷载分担比相差较大外,其它几根桩拟合程度都很好,表明其线形特征比较明显,可以用直线拟合,并且其斜率与其所处位置关系不大。
其次,运用数值模拟的方法对施工现场实验进行模拟,通过改变各影响参数分析其对桩体轴力,桩土荷载分担和负摩擦阻力的影响。分析发现桩身轴力最大值基本上与桩半径的增加成线形关系,但是由于地层不同,不同部位的桩的线形关系并不一样,其斜率并不相等。
最后利用多元统计中的超趋势面分析原理,对单因素的数值模拟结果进行拟合超趋势面,然后对多因素同时影响的CFG桩的受力特性进行分析,直观的观察到不同因素之间是如何相互作用的。分析表明桩长及桩半径对桩的轴力影响较大,褥垫层厚度较大时对桩的轴力影响较小,桩身刚度对桩轴力的影响较小,调整桩长和桩径可以取得桩体轴力的最小值。
The time of the CFG pile composite foundation research is about 20 year, since the first research to it in 1988.In these years,because this technology has the quickly construction speed, the time of construction is short, the quality easy to control and the building cost of projects is low, it has received the engineering's high praise and was widely used in foundation treatment.
This article analysised and discussed the force characteristic of it base on the the CFG pile compound ground treatment project of Nanchong Northern Sichuan Province Medical School hospital buiding. The analysis method used by this article is experiment data analysis at the first step. Then creat three-dimensional model based on the first step to analyse the rammed expanded CFG pile. Afterward uses the hyper-trend surface by numerical simulation's data the analysis method to study the influence which caused by many factors simultaneously change to the rammed expanded CFG pile.
First, it was studied that the axial force transmission and the load shares ratio of pile and soil by the experiment data analysis. And it was Selected the short-term observation experiment's five piles to carry on the analysis. Through compare the load shares ratio curve of pile and soil to straight line found that except one pile having big error at Initial time all pile's load shares ratio curve are similar to straight line. It indicated that its linear characteristic is quite obvious and could use the straight line to replaces the cuve and the slope ratio of it is irrelevant with its position.
Secondly, execute simulation using numerical simulation's method to simulate the construct-location experiment. By the way to changes each influence parametric analysis its influence to the pile axial force, the load shares ratio of pile and soil and negative friction force. Through the analysis found that the pile a axial force maximum value basically increases at the linear relations with the pile radius, but because the stratum is different, at different positon pile's linear relations are dissimilar and its slope ratio is not equal.
Finally, useing multi-dimensional statistics' hyper-trend surface analysis principle,created a hyper-trend surface with the single factor's numerical simulation result. Then analised the CFG pile's force characteristic at the multi-factors affects, to observe the interaction of different factors. The analysis indicated that the pile length and the pile radius are big influence factors to the pile axial force. When mattress thickness is big it has small infuence to the pile axial force. The pile rigidity has small inflence to the pile axial force. by adjustment the pile length and the pile diameter may obtain the the minimum value of the pile axial force.
本文结合南充市川北医学院住院楼的CFG桩复合地基处理工程,利用数值模拟和多元统计的方法对夯扩CFG的受力特性进行了探讨和研究。分析采用的方法是先对实验数据进行分析,然后在此基础上建立施工场地的三维数值模型,利用数值分析的方法分析各种因数对夯扩CFG桩受力特性的影响,之后再以数值分析的数据采用超趋势面的分析方法研究多个因素同时变化对夯扩CFG桩承载特性的影响。
首先,通过现场实验数据对夯扩CFG复合地基桩的轴力传递和桩土荷载分担比进行了分析,选取了短期观测实验的五根桩进行分析,通过对桩土荷载分担比的线形拟合发现,除其中一根桩由于初始桩土荷载分担比相差较大外,其它几根桩拟合程度都很好,表明其线形特征比较明显,可以用直线拟合,并且其斜率与其所处位置关系不大。
其次,运用数值模拟的方法对施工现场实验进行模拟,通过改变各影响参数分析其对桩体轴力,桩土荷载分担和负摩擦阻力的影响。分析发现桩身轴力最大值基本上与桩半径的增加成线形关系,但是由于地层不同,不同部位的桩的线形关系并不一样,其斜率并不相等。
最后利用多元统计中的超趋势面分析原理,对单因素的数值模拟结果进行拟合超趋势面,然后对多因素同时影响的CFG桩的受力特性进行分析,直观的观察到不同因素之间是如何相互作用的。分析表明桩长及桩半径对桩的轴力影响较大,褥垫层厚度较大时对桩的轴力影响较小,桩身刚度对桩轴力的影响较小,调整桩长和桩径可以取得桩体轴力的最小值。
The time of the CFG pile composite foundation research is about 20 year, since the first research to it in 1988.In these years,because this technology has the quickly construction speed, the time of construction is short, the quality easy to control and the building cost of projects is low, it has received the engineering's high praise and was widely used in foundation treatment.
This article analysised and discussed the force characteristic of it base on the the CFG pile compound ground treatment project of Nanchong Northern Sichuan Province Medical School hospital buiding. The analysis method used by this article is experiment data analysis at the first step. Then creat three-dimensional model based on the first step to analyse the rammed expanded CFG pile. Afterward uses the hyper-trend surface by numerical simulation's data the analysis method to study the influence which caused by many factors simultaneously change to the rammed expanded CFG pile.
First, it was studied that the axial force transmission and the load shares ratio of pile and soil by the experiment data analysis. And it was Selected the short-term observation experiment's five piles to carry on the analysis. Through compare the load shares ratio curve of pile and soil to straight line found that except one pile having big error at Initial time all pile's load shares ratio curve are similar to straight line. It indicated that its linear characteristic is quite obvious and could use the straight line to replaces the cuve and the slope ratio of it is irrelevant with its position.
Secondly, execute simulation using numerical simulation's method to simulate the construct-location experiment. By the way to changes each influence parametric analysis its influence to the pile axial force, the load shares ratio of pile and soil and negative friction force. Through the analysis found that the pile a axial force maximum value basically increases at the linear relations with the pile radius, but because the stratum is different, at different positon pile's linear relations are dissimilar and its slope ratio is not equal.
Finally, useing multi-dimensional statistics' hyper-trend surface analysis principle,created a hyper-trend surface with the single factor's numerical simulation result. Then analised the CFG pile's force characteristic at the multi-factors affects, to observe the interaction of different factors. The analysis indicated that the pile length and the pile radius are big influence factors to the pile axial force. When mattress thickness is big it has small infuence to the pile axial force. The pile rigidity has small inflence to the pile axial force. by adjustment the pile length and the pile diameter may obtain the the minimum value of the pile axial force.
引文
[1]张爱军,谢定义等,复合地基三维数字分析[B],科学出版社,2004,(2)
[2]刘汉东,张勇,贾金禄,岩土工程数值计算方法[B],黄河水利出版社,1995(12)
[3]DuncanJM,Chang.Non-linear analysis of stresses and strain in solils.In:Proc.Journal of MFD.ASCE,1970,96SM(5):1629-1653
[4]池跃君,宋二祥,陈肇元,刚性桩复合地基在不同荷载下的桩土分担特性[J],天津大学学报,2003(3)
[5]杨素春,CFG桩桩土应力比及褥垫层厚度研究[J],工业建筑,2004(6)
[6]冯震,王连俊,王娜,丁铭绩,刘升传,CFG桩横向荷载作用下竖向沉降和承载力的试验研究[J],北京交通大学学报,2007(4)
[7]肖兵,张敏勇,平板载荷试验应思考的几个问题[J],岩土力学,2003(S1)
[8]贺武斌,梁仁旺,王奎华,关于半刚性桩复合地基若干问题的研究[J],水利学报,2003(5)
[9]周龙翔,童华炜,王梦恕,张顶立,复合地基褥垫层的作用及其最小厚度的确定[J],岩土工程学报,2005(7)
[10]Balaam N P.Settlement Analysis of Soft Clays Reinforced with Granular Pile.1977
[11]Balaam N P et.alThe Behaviour of Foundation Supported by Clay Stabilised by Stone Columns.Proc.of 8th ECSMFE,1983,1
[12]HIBBITTD,KARLSSON,SORENSEN.ABAQUS theorymanual[M].Pawtucket,USA:Hibbitt,Karls2 son&SorensenInc,2000.
[13]THOMAS H R,ZHOU Z.An analysis of factors that govern the minimum time step size to be used in the finite element analysis of diffusion problems[J].Communications in Numerical Methods in Engineering,1998,14(9):809-819.
[14]VAN L H,VERMEER P A.Automatic step size correction for non-associated plasticity problem[J].International Journal for Numerical Methods in Engineering,1990,29:578-579.
[15]姜蓉,李昌宁,软土地基CFG桩加固技术[J],交通运输工程学报,2004(3)
[16]王凤池,朱浮声,康玉梅,陈百铃,复合地基沉降的模型预测[J],东北大学学报(自然科学版),2004(10)
[17]潘星,CFG桩复合地基沉降计算探讨[J],岩土力学,2005(S1)
[18]张建伟,戴自航,CFG桩复合地基褥垫层效用的有限元分析[J],岩土力学,2005(S1)
[19]何结兵,洪宝宁,丘国锋,高速公路CFG桩复合地基褥垫层作用机理研究[J],岩土力学,2004(10)
[20]孟文清,焦健,曹东源,未确知有理数在CFG桩复合地基设计中的应用[J],路基工程,2007(3)
[21]Yamamoto K,Otani J.Bearing Capacity Analysis of Reinforced Foundation Ground,Proceedings of the ninth international conference on computer methods and advances in geomechanics,Blakely,1997,3,2339-2344
[22]张丽华,于晓东,牛芩涛,高层建筑CFG桩复合地基沉降的全过程安全控制[J],煤炭工程,2006(10)
[23]张晗,王士杰,冯利军,朱常志,LS-SVM在CFG桩复合地基承载力预测中的应用[J],河北农业大学学报,2007(1)
[24]张京穗,彭勇波,刘章军,基于模糊层次分析的CFG桩复合地基辅助神经网络设计[J],西安建筑科技大学学报(自然科学版),2006(3)
[25]齐宏伟,李文华,基于BP算法的CFG桩复合地基承载力的神经网络预测[J],工业建筑,2005(S1)
[26]朱志刚,北京夕照寺小区4-住宅楼CFG桩复合地基质量问题分析处理[J],岩石力学与工程学报,2005(1)
[27]王浩,路永平,胡社荣,北京市中心区CFG桩复合地基场地区划[J],工程勘察,2007(4)
[28]刘伟,洪福亮,北京科技大学高层学生公寓楼地基的CFG桩加固[J],工业建筑,2005(S1)
[29]叶焱,CFG短桩复合地基在将府家园建筑群地基处理中的应用[J],建筑科学,2005(3)
[30]马骥,张震,张东刚,等,碎石桩和CFG桩联合加固地基的工程应用[J],施工技术,2007(8)
[31]郑晓,廖志浓,地震作用下CFG桩复合地基动力特性分析[J],铁道建筑,2007(8)
[32]廖文彬,CFG桩复合地基在严重液化地基处理中的应用[J],中国农村水利水电,2005(4)
[33]刘新福,京津城际轨道工程试验段CFG桩施工工艺及质量控制[J],铁道建筑,2007(4)
[34]王丰胜,芜湖长江大桥南岸接线工程CFG桩复合地基承载力评价[J],合肥工业大学学报(自然科学版),2005(11)
[35]黄丰,代书学,何勇,CFG桩在苏通大桥预制场地基处理中的运用[J],施工技术,2005(S1)
[36]何结兵,洪宝宁,丘国锋,高速公路CFG桩复合地基褥垫层作用机理研究[J],岩土力学,2004(10)
[37]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)
[38]中国建筑西南勘察研究院.夯扩干硬性混凝土桩复合地基工程特性的试验研究现场实验报告
[39]徐之纶.弹性力学,第四版(上册)[M].北京:高等教育出版社,2006.
[40]刘波,韩彦辉(美国).FLAC原理、实例与应用指南.人民交通出版社,2006.
[41]胥泽银,郭科.多元统计方法及其程序设计.成都:四川科学技术出版社,1999.
[42]李玉梅,袁里,彭森,等.P元Q次超趋势面的算法研究及在油藏描述中的应用[J].西安石油学院学报(自然科学版),2002(4):15-16
[43]中国农业科学研究院研究生院.正交设计[M/OL]
[44]闫明礼,张东刚,CFG桩复合地基技术及工程实践(第二版)[B],中国水利水电出版社,2006(10)
[45]FLAC3D Online Manual[EB].Minneapolis,Minnesota 55401 USA:Itasca Consulting Group,Inc,2003:81-103[2007,3]
[2]刘汉东,张勇,贾金禄,岩土工程数值计算方法[B],黄河水利出版社,1995(12)
[3]DuncanJM,Chang.Non-linear analysis of stresses and strain in solils.In:Proc.Journal of MFD.ASCE,1970,96SM(5):1629-1653
[4]池跃君,宋二祥,陈肇元,刚性桩复合地基在不同荷载下的桩土分担特性[J],天津大学学报,2003(3)
[5]杨素春,CFG桩桩土应力比及褥垫层厚度研究[J],工业建筑,2004(6)
[6]冯震,王连俊,王娜,丁铭绩,刘升传,CFG桩横向荷载作用下竖向沉降和承载力的试验研究[J],北京交通大学学报,2007(4)
[7]肖兵,张敏勇,平板载荷试验应思考的几个问题[J],岩土力学,2003(S1)
[8]贺武斌,梁仁旺,王奎华,关于半刚性桩复合地基若干问题的研究[J],水利学报,2003(5)
[9]周龙翔,童华炜,王梦恕,张顶立,复合地基褥垫层的作用及其最小厚度的确定[J],岩土工程学报,2005(7)
[10]Balaam N P.Settlement Analysis of Soft Clays Reinforced with Granular Pile.1977
[11]Balaam N P et.alThe Behaviour of Foundation Supported by Clay Stabilised by Stone Columns.Proc.of 8th ECSMFE,1983,1
[12]HIBBITTD,KARLSSON,SORENSEN.ABAQUS theorymanual[M].Pawtucket,USA:Hibbitt,Karls2 son&SorensenInc,2000.
[13]THOMAS H R,ZHOU Z.An analysis of factors that govern the minimum time step size to be used in the finite element analysis of diffusion problems[J].Communications in Numerical Methods in Engineering,1998,14(9):809-819.
[14]VAN L H,VERMEER P A.Automatic step size correction for non-associated plasticity problem[J].International Journal for Numerical Methods in Engineering,1990,29:578-579.
[15]姜蓉,李昌宁,软土地基CFG桩加固技术[J],交通运输工程学报,2004(3)
[16]王凤池,朱浮声,康玉梅,陈百铃,复合地基沉降的模型预测[J],东北大学学报(自然科学版),2004(10)
[17]潘星,CFG桩复合地基沉降计算探讨[J],岩土力学,2005(S1)
[18]张建伟,戴自航,CFG桩复合地基褥垫层效用的有限元分析[J],岩土力学,2005(S1)
[19]何结兵,洪宝宁,丘国锋,高速公路CFG桩复合地基褥垫层作用机理研究[J],岩土力学,2004(10)
[20]孟文清,焦健,曹东源,未确知有理数在CFG桩复合地基设计中的应用[J],路基工程,2007(3)
[21]Yamamoto K,Otani J.Bearing Capacity Analysis of Reinforced Foundation Ground,Proceedings of the ninth international conference on computer methods and advances in geomechanics,Blakely,1997,3,2339-2344
[22]张丽华,于晓东,牛芩涛,高层建筑CFG桩复合地基沉降的全过程安全控制[J],煤炭工程,2006(10)
[23]张晗,王士杰,冯利军,朱常志,LS-SVM在CFG桩复合地基承载力预测中的应用[J],河北农业大学学报,2007(1)
[24]张京穗,彭勇波,刘章军,基于模糊层次分析的CFG桩复合地基辅助神经网络设计[J],西安建筑科技大学学报(自然科学版),2006(3)
[25]齐宏伟,李文华,基于BP算法的CFG桩复合地基承载力的神经网络预测[J],工业建筑,2005(S1)
[26]朱志刚,北京夕照寺小区4-住宅楼CFG桩复合地基质量问题分析处理[J],岩石力学与工程学报,2005(1)
[27]王浩,路永平,胡社荣,北京市中心区CFG桩复合地基场地区划[J],工程勘察,2007(4)
[28]刘伟,洪福亮,北京科技大学高层学生公寓楼地基的CFG桩加固[J],工业建筑,2005(S1)
[29]叶焱,CFG短桩复合地基在将府家园建筑群地基处理中的应用[J],建筑科学,2005(3)
[30]马骥,张震,张东刚,等,碎石桩和CFG桩联合加固地基的工程应用[J],施工技术,2007(8)
[31]郑晓,廖志浓,地震作用下CFG桩复合地基动力特性分析[J],铁道建筑,2007(8)
[32]廖文彬,CFG桩复合地基在严重液化地基处理中的应用[J],中国农村水利水电,2005(4)
[33]刘新福,京津城际轨道工程试验段CFG桩施工工艺及质量控制[J],铁道建筑,2007(4)
[34]王丰胜,芜湖长江大桥南岸接线工程CFG桩复合地基承载力评价[J],合肥工业大学学报(自然科学版),2005(11)
[35]黄丰,代书学,何勇,CFG桩在苏通大桥预制场地基处理中的运用[J],施工技术,2005(S1)
[36]何结兵,洪宝宁,丘国锋,高速公路CFG桩复合地基褥垫层作用机理研究[J],岩土力学,2004(10)
[37]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)
[38]中国建筑西南勘察研究院.夯扩干硬性混凝土桩复合地基工程特性的试验研究现场实验报告
[39]徐之纶.弹性力学,第四版(上册)[M].北京:高等教育出版社,2006.
[40]刘波,韩彦辉(美国).FLAC原理、实例与应用指南.人民交通出版社,2006.
[41]胥泽银,郭科.多元统计方法及其程序设计.成都:四川科学技术出版社,1999.
[42]李玉梅,袁里,彭森,等.P元Q次超趋势面的算法研究及在油藏描述中的应用[J].西安石油学院学报(自然科学版),2002(4):15-16
[43]中国农业科学研究院研究生院.正交设计[M/OL]
[44]闫明礼,张东刚,CFG桩复合地基技术及工程实践(第二版)[B],中国水利水电出版社,2006(10)
[45]FLAC3D Online Manual[EB].Minneapolis,Minnesota 55401 USA:Itasca Consulting Group,Inc,2003:81-103[2007,3]