基于ABAQUS的微承压水引发基坑突涌的模拟分析
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摘要
随着城市化进程的迅猛发展,大量的基坑工程应运而生,地下水的处理作为基坑工程中的重要环节也备受关注,开展微承压水作用下基坑渗流场的数值模拟,可为基坑开挖地下水问题处理提供理论依据.本文结合实际工程,基于ABAQUS软件,建立了承压非完整井的数值模型,针对微承压水引起的局部区域的坑底突涌,分析了井深和距突涌点径向距离两个因素对减压效果的影响.研究表明,在止水帷幕的基坑工程中,降水引起的土层附加应力增加,是造成基坑底部土体竖向变形的主要原因;降水引起的基坑渗流易造成基坑支护结构变形、失稳;坑内减压降水井对坑外渗流场的影响很小;坑内减压井对坑底突涌的治理效果显著,且井深越深、井点距离突涌点越近,对突涌点的减压效果越好.
With the process of urbanization,a large number of excavation engineering came into being,and the treatment of groundwater as an important link in excavation engineering is also concerned. The numerical simulation of the seepage field of the foundation pit under the action of micro-contract pressure water can provide a theoretical basis for the treatment of the groundwater in excavation of foundation pits. In this paper,based on the actual project based on ABAQUS software,a numerical model for incomplete pressure wells is established,for pit inrush in local areas caused by micro bearing pressure water,the effect of two factors on the decompression effect,the depth of the well and the radial distance from the inrush point,was analyzed. Research shows that in the foundation pit engineering of the water-stop curtain,the vertical deformation of the soil at the bottom of the foundation pit caused by the increase of additional stress caused by precipitation is the main reason. The seepage of foundation pit caused by precipitation can easily cause deformation and instability of foundation pit supporting structure;The dewatering pit in the pit has little effect on the seepage field outside the pit. The decompression well in the pit has a significant effect on the treatment of pit bottom inrush,and the deeper the well is,the closer the well point is to the point of the inrush point,the better the decompression effect is on the inrush point.
With the process of urbanization,a large number of excavation engineering came into being,and the treatment of groundwater as an important link in excavation engineering is also concerned. The numerical simulation of the seepage field of the foundation pit under the action of micro-contract pressure water can provide a theoretical basis for the treatment of the groundwater in excavation of foundation pits. In this paper,based on the actual project based on ABAQUS software,a numerical model for incomplete pressure wells is established,for pit inrush in local areas caused by micro bearing pressure water,the effect of two factors on the decompression effect,the depth of the well and the radial distance from the inrush point,was analyzed. Research shows that in the foundation pit engineering of the water-stop curtain,the vertical deformation of the soil at the bottom of the foundation pit caused by the increase of additional stress caused by precipitation is the main reason. The seepage of foundation pit caused by precipitation can easily cause deformation and instability of foundation pit supporting structure;The dewatering pit in the pit has little effect on the seepage field outside the pit. The decompression well in the pit has a significant effect on the treatment of pit bottom inrush,and the deeper the well is,the closer the well point is to the point of the inrush point,the better the decompression effect is on the inrush point.
引文
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[7]张飞,李镜培,杨博,唐耀.黏性隔水层基坑突涌机制的离心模型试验[J].岩石力学与工程学报,2013,32(3):598-604.
[8]殷宗泽.土工原理[M].北京:中国水利水电出版社,2010.
[2]左宇军,李术才,秦泗凤,李利平.动力扰动诱发承压水底板关键层失稳的突变理论研究[J].岩土力学,2010(8):2361-2366.
[3]廖志恒.承压水上膏体充填开采底板采动破坏特征[J].煤矿安全,2018,49(4):185-188.
[4]薛森,李文平,郭启琛,刘士亮,孙梦雅,范宝江.基于FAHP-GRA评价方法的顶板承压含水层富水性预测研究[J].金属矿山,2018(4):168-172.
[5]白继文,刘人太,蒋宇静,蔚立元,张红军,李卫.条带充填置换开采围岩变形及承压水导升规律[J].采矿与安全工程学报,2018,35(2):352-358.
[6]中华人民共和国行业标准. JGJ120-2012建筑基坑支护技术规程[S].北京:中国建筑工业出版社,2012.
[7]张飞,李镜培,杨博,唐耀.黏性隔水层基坑突涌机制的离心模型试验[J].岩石力学与工程学报,2013,32(3):598-604.
[8]殷宗泽.土工原理[M].北京:中国水利水电出版社,2010.