承压水降压引起的上覆土层沉降分析-岩土工程学报.PDFVIP

33 卷 1期 岩 土 工 程 学 报 Vol.33 No.1 2011 年 .1 月 Chinese Journal of Geotechnical Engineering Jan. 2011 压水降压引起的上覆土层沉降分析 龚晓南，张 杰 (浙江大学软弱土与环境土工教育部重点实验室，浙江 杭州 310058) 摘 要：如何评估承压水降压引起的地面沉降是工程界十分关心的问题。深基坑开挖前及过程中，所进行的降压导致 深层承压水头下降，使地层应力重新分布产生地面沉降。针对顶板完全隔水的承压水层，运用完整井理论提出了反映 承压水降压 用的附加分布力公式，在Mindlin 解的基础上，推导出了承压水降压附加分布力 用下的地面沉降公式。 讨论了上覆土层厚度、上覆土层弹性模量、承压水水头降深和承压层导水系数对沉降的影响。工程实例表明，根据本 文方法得到的承压水降压引起的地面沉降较小，与工程基坑开挖后的实际表现一致。 关键词：承压水；降压；上覆土层；沉降；Mindlin 位移解 中图分类号 TU473.3 文献标识码：A 文章编号：1000 –4548(2010)01 –0145 –05 作者简介：龚晓南( 1944 – ) ，男，浙江金华人，从事地基处理方向的研究。E-mail: xngong@ 。 Settlement of overlaying soil caused by decompression of confined water GONG Xiao-nan, ZHANG Jie (Key Laboratory of Soft Soils and Geoenviromental Engineering of Ministry of Education, Zheji ang University, Hangzhou 310058, China) Abstract: How to estimate the settlement caused by pressure-relief of confined water has been a research focus in the academic and engineering fields. During the process of pumping confined water, the drop of hydraulic head leads to the decrease of uplift force, and produces extra stress on overlaying soil, resulting in the settlement of the ground. As the permeability coefficient is very small, the roof of the confined aquifer is supposed to be impermeable. By calculating steady flow of fully penetrated well of confined water, the additional force acting on the overlaying soil, which is caused by pressure-relief of confined water, is studied. Above all, the effects of some parameters on the settlement are studied, such as the thickness, modulus of the overlaying soil, head difference and transmissibility of the confined aquifer. Through an example, the settle