Research on parameter inversion for foundation pit dewatering in the Beijuma River Regulation and Storage Project

Abstract:

As a key facility of the Beijing-Tianjin-Hebei flood control system， the Beijuma River Regulation and Storage Project faces three major technical challenges in foundation pit dewatering： highly permeable pebble strata， complex riverside boundaries， and the ineffectiveness of traditional water inflow prediction methods. In this study， a triple cross-validation method combining pumping tests， foundation pit dewatering tests and numerical simulation is adopted to realize accurate inversion of hydraulic conductivity. Initial parameters are obtained through pumping tests of dewatering wells； the feasibility of high-intensity pumping and drainage is verified by a collaborative open drainage system with 36 wells during foundation pit dewatering tests. A three-dimensional seepage model is built on the GMS platform， and the hydraulic conductivity is determined via inversion using a water level residual feedback mechanism. The study verifies that for deep foundation pits in pebble strata， the numerical simulation-driven parameter inversion method can accurately characterize complex boundaries and realize closed-loop verification between parameters and dewatering effects， providing a scientific basis for water inflow prediction.