定流量下承压层环向非完整井流理论及应用  

Theory and application of circularly partial penetrating well flow in a confined aquifer under constant pumping rate

作　　者：黄大中[1] 谢康和[1] 应宏伟[1] 胡安峰[1] 

机构地区：[1]浙江大学岩土工程研究所,软弱土与环境土工教育部重点实验室,浙江杭州310058

出　　处：《浙江大学学报（工学版）》2012年第8期1437-1443,共7页Journal of Zhejiang University：Engineering Science

基　　金：浙江省自然科学基金重点资助项目(Z5080175)

摘　　要：考虑井壁沿环向一部分不透水,建立定流量下承压层环向非完整井模型,应用Laplace变换和Fourier变换得到井流问题的半解析解,并获得特殊情况下的近似解.基于所得半解析解,分析环向非完整区对流场状况的影响以及影响程度沿径向的分布和随时间的变化.计算结果表明,环向的非完整性使流场产生明显的空间分布差异,会导致定流量井流实验时应用完整井理论估算得到的含水层参数产生偏差.针对这一问题,提出减小误差的方法.环向非完整井的流场特性可用于基坑降水,以增加基坑内的降水深度而减小基坑外的降水深度,通过算例对降水效果进行验证.Considering part of the well wall was impervious in the circular direction, a circularly partial penetrating well model in a confined aquifer under constant pumping rate was set up. A semi-analytical solution of the well flow problem was obtained using Laplace transform and Fourier transform technique, and approximate solutions were available in some special situations. The effects of circularly partial penetrating area on flow field were analyzed based on the semi-analytical solution. The distribution of the degree of the effects in the radial direction and the development of those with time were also analyzed. The calculations show that great disturbs on flow field could be caused by circularly partial penetration, which would result in estimation errors of aquifer parameters when using full penetrating well theory in the constant discharge pumping test. A modified method was proposed for the flow field of circularly partial penetrating well could be used for dewate problem. The character of the ring in the foundation pit, to increase the drawdown in the pit and decrease the drawdown out of the pit. The results of pit dewatering using this method were examined through the calculations of an example.

关 键 词：环向非完整井 半解析解 积分变换 井流试验 基坑降水 

分 类 号：TU46[建筑科学—结构工程]