Engineering Transactions, 63, 4, pp. 383-396, 2015

Analysis of Distribution Model of Matric Suction of Land Subsidence Caused by Foundation Pit Dewatering

Donglin WANG
School of Civil Engineering Anhui Jianzhu University

By the soil matrix suction distribution under one-dimensional steady-state flow, soil permeability coefficient ks, infiltration intensity q and initial groundwater table factors that influence the matric suction of unsaturated soil were analyzed in this paper. Based on unsaturated soil mechanics theory, ground subsidence caused by dewatering was calculated for typical pits and the impact of non-saturated soil matrix suction value on ground subsidence was taken into consideration. The results has shown that under steady infiltration conditions (q/ks < 0), the deformation of subsidence in unsaturated zone was bigger than the initial suction with still water distribution (q/ks= 0), while under stable evaporation conditions (q/ks > 0), the deformation of subsidence in unsaturated zones was smaller than the initial suction with still water distribution. In addition, as the groundwater table was lower, the influence of distribution patterns of the initial matrix suction in unsaturated soil on deformation of ground subsidence was greater.
Keywords: unsaturated soil; matrix suction; land subsidence; foundation pit dewatering
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Chen X.-X., Luo Z.-J., Zhou S.-L., Influences of soil hydraulic and mechanical parameters on land subsidence and ground fissures caused by groundwater exploitation, Journal of Hydrodynamics, 26, 1, 155–164, 2014.

Hu X., Song D., Wang S. et al., Analysis of correlation between groundwater exploitation and subsidence in certain areas along Beijing-Shanghai high-speed railway, Chinese Journal of Rock Mechanics and Engineering, 30, 9, 1738–1746, 2011.3. Zhou N.-Q., Tang Y.-Q., Lou R.-X., Jiang S.-M., Numerical simulation of deep foundation pit dewatering and land subsidence control of Xujiahui Metro Station, Chinese Journal of Geotechnical Engineering, 33, 12, 1951–1956, 2011.

Shan H.Y., Lo W.J., Deformation characteristics of shallow aquifer soils, [in:] Proceedings of the Second International Conference on Unsaturated Soils, Beijng, China, 125–130, 1998.

Wang D., Luan M., Yang Q., Application of unsaturated soil constitutive model, Rock and Soil Mechanics, 29, 12, 3311–3317, 2008.

Wang D., Luan M., Yang Q., Experimental study on volume change of unsaturated soils and its application to estimation of subsidence, Journal of Disaster Prevention and Mitigation Engineering, 27, 3, 307–311, 2007.

Fredlund D.G., Rahardjo H., Soil mechanics for unsaturated soils, John Wiley & Sons Press, New York, 1993.

Qian J.-H., Ying Z.-Z., The principle and calculation of earthwork, NANJing: China Waterpower Press, 1996.

Jin X.-R., Yu J-L., Zhu S.-C., Analysis of behaviors of settlement of pit’s surrounding soils by dewatering, Rock and Soil Mechanics, 26, 10, 1575–1581, 2005.

Van Genuchten M.Th., A closed-form equation for predicting the hydraulic conductivity for unsaturated soils, Journal of the Soil Science Society of America, 44, 892–892, 1980.

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