Evaluation of optimized depth of waterproof curtain to mitigate negative impacts during dewatering
Evaluation of optimized depth of waterproof curtain to mitigate negative impacts during dewatering
复制标题
评估防水幕优化深度以减轻脱水过程中的负面影响
DOI：
10.1016/j.jhydrol.2019.123969
复制
发表时间：
2019-10-01
影响因子：
6.4
通讯作者：
Shen, Shui-Long
中科院分区：
文献类型：
--
作者：
Wang, Xu-Wei;Yang, Tian-Liang;Shen, Shui-Long
为保证多含水层基坑的稳定性，通常采用帷幕与抽威尔斯井联合降水。然而，脱水可能导致环境问题。采用数值模拟的方法研究了止水帷幕与抽威尔斯井相互作用对周围环境的影响。在模拟中，地下连续墙穿过降水含水层的深度（D）和抽水威尔斯井的过滤长度（L）是变化的。近似水力坡降（Δ i）或基坑外地表沉降（S）与帷幕深度比R-D（D与降水承压含水层厚度H-a之比）或反滤长度比R-L（L/H-a）的关系可分为3个变化部分，即初期平缓、中期急剧和后期平缓。提出了R-D和R-L的三个值，即有效值、建议值和控制值。R-D和R-L应在有效值和对照值之间变化。在实际工程中综合考虑，推荐了R-D和R-L的建议值。根据R-L值，可通过线性方程计算出R-D的有效值、建议值和控制值。
Dewatering using a combination of waterproof curtain and pumping wells is commonly adopted to ensure the stability of foundation pits in multi-aquifer strata. However, dewatering is likely to result in environmental problems. This paper investigates the impact on surroundings owing to the interaction between the waterproof curtain and pumping wells by numerical simulation. The depth of the diaphragm wall penetrating the dewatering aquifer (D) and the filter length of pumping wells (L) are varied in the simulation. The relationship between approximate hydraulic gradient (Delta i) or ground settlement outside the foundation pit (S) with curtain depth ratio R-D (D over the thickness of the dewatering confined aquifer H-a) or filter length ratio R-L (L/H-a) can be divided into three change parts, namely initial gradual, middle sharp and final gentle part. Three values of R-D and R-L, namely effective, suggested and control value, are proposed. R-D and R-L should vary between the effective and control value. The suggested value of R-D and R-L, is recommended in actual engineering by comprehensive consideration. The effective, suggested and control value of R-D can be calculated by a linear equation according to the value of R-L.