波动承压水下基坑底部弱透水层的非Darcy渗流分析

展开
  • 1.浙江大学 滨海和城市岩土工程研究中心;浙江省城市地下空间开发工程技术研究中心;软弱土与环境土工教育部重点实验室,杭州  310058
    2.浙江大学城市学院 土木工程系,杭州  310015
应宏伟(1971-),男,江西省萍乡市人,教授,现就任于河海大学,主要从事岩土工程方面的教学和科研工作.E-mail: ice898@zju.edu.cn.

收稿日期: 2019-02-12

  网络出版日期: 2020-12-31

基金资助

国家自然科学基金项目(51678523);国家自然科学基金青年项目(51808492)

Analysis of Non-Darcy Flow in Aquitard at Bottom of Foundation Pit Under Fluctuation of Confined Water

Expand
  • 1.Research Center of Coastal and Urban Geotechnical Engineering; Engineering Research Center of Urban Underground Development of Zhejiang Province; MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China
    2.Department of Civil Engineering, Zhejiang University City College, Hangzhou 310015, China

Received date: 2019-02-12

  Online published: 2020-12-31

摘要

为了更好地解释由承压水引起的基坑突涌现象,从渗流固结的角度出发,将Hansbo非 Darcy 渗流方程引入饱和土的Terzaghi一维固结方程中.采用有限差分法,求得由波动承压水引起的超孔压数值解,并将其退化到Darcy渗流情况与已有解析解进行对比,分析了非Darcy参数、承压水波动周期和初始水位对弱透水层超孔压变化规律的影响.结果表明:在波动承压水作用下,弱透水层中的超孔压随波动时间的延长而增加,若干周期后达到稳定波动状态.非Darcy渗流试验常数和直线段的起始水力坡降越大,超孔压的传递滞后现象越明显,振幅越小;承压水波动周期越长或者初始水位越高,超孔压的振幅越大;基坑底板承受的初始承压水位越高,超孔压受到承压水变化的影响越明显.工程应用的实例表明,考虑土体非Darcy因素时可以适当降低承压水位的设计下降深度.

本文引用格式

应宏伟, 许鼎业, 王迪, 章丽莎 . 波动承压水下基坑底部弱透水层的非Darcy渗流分析[J]. 上海交通大学学报, 2020 , 54(12) : 1300 -1306 . DOI: 10.16183/j.cnki.jsjtu.2019.036

Abstract

In order to better explain the phenomenon of foundation pit inrush caused by confined water, the Hansbo non-Darcy seepage theory was introduced into the Terzaghi one-dimensional saturated soil consolidation equation. Finite difference methods were applied to the numerical solution of excess pore pressure caused by the fluctuation of confined water. Then, the numerical solution was reduced to Darcy seepage and compared with the analytical solution. The effects of non-Darcy parameters, fluctuation periods of confined water, and initial water levels on the variation of excess pore pressure in the aquitard were analyzed. The results show that the excess pore pressure in aquitard volatility increases over time under the fluctuation of confined water, and reaches a stable fluctuating state after several cycles. The greater the initial hydraulic gradient and test constant of non-Darcy, the more obvious the hysteresis phenomenon of excess pore pressure, and the smaller the amplitude. The longer period of pressure water fluctuation or the higher the initial water level, the greater the amplitude of excess pore pressure oscillation. In addition, when the base is subjected to higher levels of initial confined water, the excess pore pressure in aquitard becomes more susceptible to the change of confined water pressure. The application of a case indicates that the designed drawdown depth of the confined water level could be reduced if the non-Darcy factor is considered.

参考文献

[1] MILLIGAN V, LO K Y. Observations on some basal failures in sheeted excavations[J]. Canadian Geotechnical Journal, 1970, 7(2): 136-144.
[2] 车灿辉,张智博,刘实. 南京长江漫滩地区某深基坑突水原因分析及治理[J]. 岩土工程技术,2014, 28(4): 183-187.
[2] CHE Canhui, ZHANG Zhibo, LIU Shi. Analysis and management of confined water inrush of a deep foundation pit the floodplain area of Nanjing Yangtze River[J]. Geotechnical Engineering Technique, 2014, 28(4): 183-187.
[3] 徐长节,徐礼阁,孙凤明,等. 深基坑承压水的风险控制及处理实例[J]. 岩土力学,2014, 35(Sup.1): 353-358.
[3] XU Changjie, XU Lige, SUN Fengming, et al. Risk control and dealing example of confined water of deep foundation pit[J]. Rock and Soil Mechanics, 2014, 35(Sup.1): 353-358.
[4] ZHOU P P, LI G M, LU Y D.Numerical modeling of tidal effects on groundwater dynamics in a multi-layered estuary aquifer system using equivalent tidal loading boundary condition: Case study in Zhanjiang, China[J]. Environmental Earth Sciences, 2016, 75(2): 1-16.
[5] 付丛生,陈建耀,曾松青,等. 滨海地区潮汐对地下水位变化影响的统计学分析[J]. 水利学报,2008, 39(12): 1365-1376.
[5] FU Congsheng, CHEN Jianyao, ZENG Songqing, et al. Statistical analysis on impact of tide on water table fluctuation in coastal aquifer[J]. Journal of Hydraulic Engineering, 2008, 39(12): 1365-1376.
[6] HONG Y, NG C W W, WANGL Z. Initiation and failure mechanism of base instability of excavations in clay triggered by hydraulic uplift[J]. Canadian Geotechnical Journal, 2015, 52(5): 1-10.
[7] 丁春林. 软土地区承压水基坑突涌稳定计算法研究综述[J]. 地下空间与工程学报,2007, 3(2): 333-338.
[7] DING Chunlin. Summary of study on calculation method of inrushing for confined water foundation pit in soft soil area[J]. Chinese Journal of Underground Space and Engineering, 2007, 3(2): 333-338.
[8] 王玉林,谢康和,卢萌盟,等. 受承压水作用的基坑底板临界厚度的确定方法[J]. 岩土力学,2010, 31(5): 1539-1544.
[8] WANG Yulin, XIE Kanghe, LU Mengmeng, et al. A method for determining critical thickness of base soil of foundation pit subjected to confined water[J]. Rock and Soil Mechanics, 2010, 31(5): 1539-1544.
[9] 章丽莎,应宏伟,谢康和,等. 动态承压水作用下深基坑底部弱透水层的出逸比降解析研究[J]. 岩土工程学报,2017, 39(2): 295-300.
[9] ZHANG Lisha, YING Hongwei, XIE Kanghe, et al. Analytical study on exit gradient at base aquitard of deep excavations under dynamic artesian water[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(2): 295-300.
[10] CONTE E, TRONCONE A. Soil layer response to pore pressure variations at the boundary[J]. Géotechnique, 2008, 58(1): 37-44.
[11] CAVALERA L. Consolidation under cyclic variation of boundary pore pressure[J]. Rivista Italiana Geotecnica, 1977, 11(4): 187-205.
[12] 刘凯,文章,梁杏,等. 一维低渗透介质非达西渗流实验[J]. 水动力学研究与进展A辑,2013, 28(1): 81-87.
[12] LIU Kai, WEN Zhang, LIANG Xing, et al. One-dimensional column test for non-Darcy flow in low permeability media[J]. Chinese Journal of Hydrodyna-mics, 2013, 28(1): 81-87.
[13] DENG Y E, XIE H P, HUANG R Q, et al. Law of nonlinear flow in saturated clays and radial consolidation[J]. Applied Mathematics and Mechanics, 2007, 28(11): 1427-1436.
[14] HANSBO S. Consolidation equation valid for bothDarcian and non-Darcian flow[J]. Géotechnique, 2001, 51(1): 51-54.
[15] 李传勋,徐超,谢康和. 考虑非Darcy渗流和应力历史的土体非线性固结研究[J]. 岩土力学,2017, 38(1): 91-100.
[15] LI Chuanxun, XU Chao, XIE Kanghe. Nonlinear consolidation of clayed soil considering non-Darcy flow and stress history[J]. Rock and Soil Mechanics, 2017, 38(1): 91-100.
[16] 刘忠玉,闫富有,王喜军. 基于非Darcy渗流的饱和黏性土一维流变固结分析[J]. 岩石力学与工程学报,2013, 32(9): 1937-1944.
[16] LIU Zhongyu, YAN Fuyou, WANG Xijun. One-dimensional rheological consolidation analysis of saturated clay considering non-Darcy flow[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(9): 1937-1944.
[17] 时刚,刘忠玉,李永辉.循环荷载作用下考虑非达西渗流的软黏性土一维流变固结分析[J]. 岩土力学,2018, 39(Sup.1): 521-528.
[17] SHI Gang, LIU Zhongyu, LI Yonghui. One-dimensional rheological consolidation of soft clay under cyclic loadings considering non-Darcy flow[J]. Rock and Soil Mechanics, 2018, 39(Sup.1): 521-528.
[18] 张文生. 科学计算中的偏微分方程有限差分法[M]. 北京: 高等教育出版社,2006: 245-249.
[18] ZHANG Wensheng. Finite difference methods for partial differential equations in science computation[M]. Beijing: Higher Education Press, 2006: 245-249.
文章导航

/