Land subsidence caused by pits seepage erosion of deep foundation with suspended diaphragm walls in Shanghai
ZHANG Xing-sheng1, LU Yao-ru2, WANG Jian-xiu2, WONG Henry3, LIU Qi2
1. Institute of Resources and Environment, North China Institute of Water Resources and Electric Power, Zhengzhou 450011, China; 2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 3. Dé partement Gé nie Civil et Bâ timent, Université de Lyon, Ecole Nationale des Travaux Publics de l’ Etat, Vaulx-en-Velin 69120, France
Abstract：According to analysis of the phenomenon of internal erosion of soils, the phenomenon of internal erosion of soils is that some soil particles departing from soil skeletons become fluidized ones sharing the same velocity with fluid phase. A physical model for the internal erosion of soils is established, and the correspoding constitutive equation is given. The land subsidence caused by the internal erosion of soils owing to pumping confined groundwater is discussed during the construction of third-class deep foundation pits. The numerical model depends on a practical deep foundation pit consisting of 8 layers of soils of Shanghai area. Based on the mathematical-physical model, four governing equations and the finite element numerical method, the calculated results demonstrate that the internal erosion will cause additional land subsidence and deformation.
张兴胜, 卢耀如, 王建秀, 刘琦. 上海悬挂式地下连续墙基坑渗流侵蚀引起的沉降研究[J]. 岩土工程学报, 2014, 36(zk2): 284-290.
ZHANG Xing-sheng, LU Yao-ru, WANG Jian-xiu, WONG Henry, LIU Qi. Land subsidence caused by pits seepage erosion of deep foundation with suspended diaphragm walls in Shanghai. Chinese J. Geot. Eng., 2014, 36(zk2): 284-290.
[1] 吴林高. 工程降水设计施工与基坑渗流理论[M]. 北京: 人民交通出版社, 2003. (WU LG. Design and construction of dewatering engineering and theory of pit seepage[M]. Beijing: China Communication Press, 2003. (in Chinese)) [2] WANG Jian-xiu, FENG Bo, LIU Yan, et al. Controlling subsidence caused by de-watering in a deep foundation pit[J]. Bull Eng Environ, 2012, 71: 545-555. [3] ZHANG X S, WONG H, LEO C J, et al. A thermodynamics-based model on the internal erosion of earth structures[J]. Geotechnical and Geological Engineering, 2013, 31: 479-492. [4] OLIVIER Coussy. Poromechanics[M]. West Sussex: John wiley & Sons Ltd, 2004. [5] PAPAMICHOS E, VARDOULAKIS I. Sand erosion with a porosity diffusion law[J]. Computers and Geotechnics, 2005, 32(1): 47-58. [6] JEAN Lemaitre. A course on damage mechanics[M]. Verlag Berlin: Springer, 1991. [7] REDDI L N, LEE I M, BOONALA M V S. Comparison of internal and surface erosion using flow pump tests on a sand-kaolinite mixture[J]. Geotechnical Tesitng Journal, 2000, 23(1): 116-122.
