北拒马河调蓄工程基坑降水参数反演研究

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

摘要:

北拒马河调蓄工程作为京津冀防洪体系的关键设施，其基坑降水面临强透水卵石地层、临河边界复杂及传统涌水量预测方法失效三大技术挑战。本研究采用抽水试验-基坑降水试验-数值模拟三重交叉验证方法，实现渗透系数的精准反演：通过降水井抽水试验获取初始参数；结合基坑降水试验中36口井协同明排系统验证高强度抽排可行性；基于GMS平台构建三维渗流模型，通过水位残差反馈机制反演确定渗透系数。研究证实针对卵石地层深基坑，数值模拟驱动的参数反演方法可实现复杂边界精准刻画与参数-效果闭环验证，为涌水量预测提供科学依据。

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.