渗透各向异性对基坑工程性状的影响研究
|
摘要
天然沉积的土体在结构构造上呈现出各向异性特征,因而在渗透上也呈现出各向异性特征。基于比奥固结理论,开发出了考虑渗流与土骨架变形耦合的三维基坑有限元程序,分别分析竖向渗透系数不变时和水平向渗透系数不变时渗透各向异性对基坑变形的影响。研究表明,无论是水平向渗透系数不变还是竖向渗透系数不变时,随着渗透各向异性系数的增大,支护结构的水平位移都增大,坑外较远距离处的地表沉降都减小;但对于坑底隆起变形,则是当水平向或者竖向渗透系数不变时,另一个方向的渗透系数越大,坑底的隆起变形量越大。因此,在进行基坑工程建设时,应考虑渗透各向异性的影响。
Natural sedimentary soil shows the characteristics of anisotropy in fabric structure,thus also shows the characteristics of anisotropy in permeability. Based on Biot's consolidation theory,a three-dimensional finite element program for excavation was developed considering the coupling of seepage and deformation of soil skeleton. The effect of anisotropic permeability on the behavior of excavation was analyzed when the vertical or horizontal permeability coefficient of soil is constant respectively. Studies show that the horizontal displacement of supporting structure increases and ground settlement at a certain distance from retaining structure decreases with the increase of permeability anisotropy coefficient. However,when the horizontal or vertical permeability coefficient is constant,heave deformation of pit base is larger with the increase of permeability coefficient on another direction. Therefore,anisotropic permeability of soil should be considered when an excavation is constructed.
Natural sedimentary soil shows the characteristics of anisotropy in fabric structure,thus also shows the characteristics of anisotropy in permeability. Based on Biot's consolidation theory,a three-dimensional finite element program for excavation was developed considering the coupling of seepage and deformation of soil skeleton. The effect of anisotropic permeability on the behavior of excavation was analyzed when the vertical or horizontal permeability coefficient of soil is constant respectively. Studies show that the horizontal displacement of supporting structure increases and ground settlement at a certain distance from retaining structure decreases with the increase of permeability anisotropy coefficient. However,when the horizontal or vertical permeability coefficient is constant,heave deformation of pit base is larger with the increase of permeability coefficient on another direction. Therefore,anisotropic permeability of soil should be considered when an excavation is constructed.
引文
[1]Dafalias Y F,Papadimitriou A G,Li X S.Sand plasticity model accounting for inherent fabric anisotropy[J].Journal of Engineering Mechanics,2004,130(11):1319-1333.
[2]Li X S,Dafalias Y F.A constitutive framework for anisotropy sand including non-proportional loading[J].Geotechnique,2004,54(1):41-55.
[3]Gao Z W,Zhao J D,Li X S,Dafalias Y F.Constitutive modeling of fabric anisotropy in sand[A]//International Symposium on Geomechanics from Micro to Macro[C].IS-Cambridge,2014:621-626.
[4]邱珍锋.砂泥岩混合料各向异性渗透特性试验研究[D].重庆:重庆交通大学,2013.(Qiu Zhenfeng.Experimental study on anisotropic permeability characteristics of sandstone-mudstone particle mixture[D].Chongqing:Chongqing Jiaotong Universtiy,2013.(in Chinese))
[5]闫小波.软岩各向异性渗透特征及力学特征的试验研究[D].上海:同济大学,2006.(Yan Xiaobo.Experimental study on permeability characteristics and mechanical properties of soft rock[D].Shanghai:Tongji University,2006.(in Chinese))
[6]Sun J P,Zhao Z Y.Effects of anisotropic permeability of fractured rock masses on underground oil storage caverns[J].Tunneling and Underground Space Technology,2010,25(5):629-637.
[7]Wang H L,Chu W J,He M.Anisotropic permeability evolution model of rock in the process of deformation and failure[J].Journal of Hydrodynamics,2012,24(1):25-31.
[8]黄大中,谢康和,应宏伟.渗透各向异性土层中基坑二维稳定渗流半解析解[J].浙江大学学报(工学版),2014,48(10):1802-1808.(Huang Dazhong,Xie Kanghe,Ying Hongwei.Semi-analytical solution for two-dimensional steady seepage around foundation pit in soil layer with anisotropic permeability[J].Journal of Zhejiang University(Engineeringscience),2014,48(10):1802-1808.(in Chinese))
[9]Li Y Q,Zhou J,Xie K H.Environmental effects induced by excavation[J].Journal of Zhejiang University Science A:2008,9(1):50-57.
[10]李玉岐.考虑渗流影响的基坑工程性状研究[D].杭州:浙江大学,2005.(Li Yuqi.Studies on the behavior of foundation pit with excavation considering seepage[D].Hangzhou:Zhejiang University,2005.(in Chinese))
[11]李玉岐,周旋,谢康和.坑外荷载对软土地区基坑开挖变形性状的影响[J].建筑科学与工程学报,2016,33(4):97-102.(Li Yuqi,Zhou Xuan,Xie Kanghe.Influence of outside load on deformation behavior of foundation pit excavation in soft soil area[J].Journal of Architecture and Civil Engineering,2016,33(4):97-102.(in Chinese))
[12]Yin Z Z,Zhu H,Xu G H.A study of deformation in the interface between soil and concrete[J].Computers and Geotechnics,1995,17(1):75-92.
[13]李玉岐,周健,谢康和.基坑开挖卸载诱发的渗流分析[J].岩土工程学报,2006,28(10):1259-1262.(Li Yuqi,Zhou Jian,Xie Kanghe.Analysis of seepage induced by excavation[J].Chinese Journal of Geotechnical Engineering,2006,28(10):1259-1262.(in Chinese))
[2]Li X S,Dafalias Y F.A constitutive framework for anisotropy sand including non-proportional loading[J].Geotechnique,2004,54(1):41-55.
[3]Gao Z W,Zhao J D,Li X S,Dafalias Y F.Constitutive modeling of fabric anisotropy in sand[A]//International Symposium on Geomechanics from Micro to Macro[C].IS-Cambridge,2014:621-626.
[4]邱珍锋.砂泥岩混合料各向异性渗透特性试验研究[D].重庆:重庆交通大学,2013.(Qiu Zhenfeng.Experimental study on anisotropic permeability characteristics of sandstone-mudstone particle mixture[D].Chongqing:Chongqing Jiaotong Universtiy,2013.(in Chinese))
[5]闫小波.软岩各向异性渗透特征及力学特征的试验研究[D].上海:同济大学,2006.(Yan Xiaobo.Experimental study on permeability characteristics and mechanical properties of soft rock[D].Shanghai:Tongji University,2006.(in Chinese))
[6]Sun J P,Zhao Z Y.Effects of anisotropic permeability of fractured rock masses on underground oil storage caverns[J].Tunneling and Underground Space Technology,2010,25(5):629-637.
[7]Wang H L,Chu W J,He M.Anisotropic permeability evolution model of rock in the process of deformation and failure[J].Journal of Hydrodynamics,2012,24(1):25-31.
[8]黄大中,谢康和,应宏伟.渗透各向异性土层中基坑二维稳定渗流半解析解[J].浙江大学学报(工学版),2014,48(10):1802-1808.(Huang Dazhong,Xie Kanghe,Ying Hongwei.Semi-analytical solution for two-dimensional steady seepage around foundation pit in soil layer with anisotropic permeability[J].Journal of Zhejiang University(Engineeringscience),2014,48(10):1802-1808.(in Chinese))
[9]Li Y Q,Zhou J,Xie K H.Environmental effects induced by excavation[J].Journal of Zhejiang University Science A:2008,9(1):50-57.
[10]李玉岐.考虑渗流影响的基坑工程性状研究[D].杭州:浙江大学,2005.(Li Yuqi.Studies on the behavior of foundation pit with excavation considering seepage[D].Hangzhou:Zhejiang University,2005.(in Chinese))
[11]李玉岐,周旋,谢康和.坑外荷载对软土地区基坑开挖变形性状的影响[J].建筑科学与工程学报,2016,33(4):97-102.(Li Yuqi,Zhou Xuan,Xie Kanghe.Influence of outside load on deformation behavior of foundation pit excavation in soft soil area[J].Journal of Architecture and Civil Engineering,2016,33(4):97-102.(in Chinese))
[12]Yin Z Z,Zhu H,Xu G H.A study of deformation in the interface between soil and concrete[J].Computers and Geotechnics,1995,17(1):75-92.
[13]李玉岐,周健,谢康和.基坑开挖卸载诱发的渗流分析[J].岩土工程学报,2006,28(10):1259-1262.(Li Yuqi,Zhou Jian,Xie Kanghe.Analysis of seepage induced by excavation[J].Chinese Journal of Geotechnical Engineering,2006,28(10):1259-1262.(in Chinese))