实际工程中基坑渗流量的估算仍采用JGJ 120—2012《建筑基坑支护技术规程》推荐的算式,而规范中的大井法并没有考虑隔水层之上悬挂止水帷幕对基坑渗流的影响。基于Schwarz-Christoffel映射理论,建立隔水层之上悬挂止水帷幕基坑渗流简化模型,并考虑成层土条件下的等效渗透系数,推导出理想边界下该类基坑渗流量式。以云南某基坑为例,运用简化模型推导的算式计算基坑渗流量,与实际渗流量进行比较,以此验证模型的有效性。
At present,the seepage discharge of an excavation with pensile curtain on reliable impermeable layer is calculated by the formula recommended by the specification.However,the big well method in the specification does not consider the influence of pensile curtain.Based on theory of Schwarz-Christoffel mapping,a simplified model of seepage was built.Then through considering the equivalent permeable coefficient of soil layers,the expression of seepage discharge of the excavation with ideal boundary conditions was derived.In order to verify the validity of the model,the model was used to calculate the seepage discharge of an excavation in Yunnan,and the calculated value was compared with the actual value.