城市区域复杂环境条件下的深基坑工程往往涉及复杂的承压水处理问题,当承压含水层深度较大且采用悬挂帷幕结合坑内减压降水方案时,需合理评估承压水降水对周边环境的影响,而其关键是要确定合理的水文地质参数。本文结合位于长江漫滩地貌单元的某深基坑工程,在基坑实施前针对其深厚承压含水层开展了现场群井抽水试验,根据单井抽水试验的解析方法给出了初步的水文地质参数,在此基础上,建立了群井抽水试验的地下水渗流数值分析模型,基于反演分析确定了合理的水文地质参数,为分析基坑承压水降水对周边环境影响提供了直接依据。

Deep foundation pit engineering under complex environmental conditions in urban areas often involves complex confined water treatment problems. When the confined aquifer is relatively deep and only the scheme of hanging curtain combined with pit decompression water can be adopted, it is necessary to assess the impact of confined water precipitation on surrounding environment. And one of the key problem is to determine reasonable hydrogeological parameters. Based on a deep excavation project located in the Yangtze River floodplain geomorphic unit, a field pumping test of multiple wells was carried out for its thick confined aquifer. The preliminary hydrogeological parameters were given according to the analytical method of single well pumping test. On this basis, a numerical analysis model of groundwater seepage for multiple well pumping test was established, and reasonable hydrogeological parameters were determined based on back analysis. It provided a direct basis for analyzing the impact of confined water dewatering on the surrounding environment.