Numerical evaluation of a 70-m deep hydropower station foundation pit dewatering

Abstract

The average depth of Yamansu hydropower station foundation pit is 70 m. The foundation pit was excavated with ve-level slopes. The lowering of groundwater level is signi cant for excavation. Drainage and pumping were adopted in dewatering. Pumping tests were performed to reverse hydraulic parameters and calibrate numerical models. Numerical simulations were performed to evaluate the dewatering scheme. In the rst stage, powerhouse tailrace canal was excavated and utilized as a drainage channel to lower the groundwater level. The drawdown and hydraulic gradient were evaluated to prevent potential water inrush, erosion, piping, and slope failure. In the second stage, cutoff wall and pumping wells were evaluated to lower the groundwater level. The in uences of depth, permeability, and thickness of the cutoff wall were evaluated. Dewatering scheme was revised accordingly based on the evaluation. The optimized dewatering scheme, which can be referred by similar engineering, was performed and veri ed successfully.

Research on the Optimal Design of Retaining Piles of a Wide Metro Tunnel Foundation Pit Based on Deformation Control

“…The deformation curve of the retaining piles on each side contains 11 undetermined coefficients, while the deformation coordination condition contains only one system of linear equations. Thus, solving Equation (10) gives an analytical solution space for the undetermined coefficients, as shown in Equation (11).…”

“…Therefore, understanding and controlling deformation is not only a technical requirement but also a safety imperative. Most scholars have explored the deformation curve using branch simulation methods, optimizing design parameters by analyzing these curves [1,2,4,[6][7][8][9][10][11][12][13][14]. These methods focus on fine-tuning the design to achieve minimal deformation while maintaining structural integrity.…”

“…Current optimization designs are primarily applied in waterproof curtain and largescale deep foundation pit engineering, focusing on structural strength and waterproof functionality [1,9,11,[15][16][17][18][19]. There are also studies that have made significant contributions by using optimization techniques to improve soil quality (Yuan et al, 2024a(Yuan et al, , 2024b, 2023 [20][21][22]).…”

Numerical analysis of metro station pit dewatering and its influence

“…Thus, studying the influence of foundation pit dewatering on the project site and surrounding environment is necessary. Currently, empirical formulas and numerical simulation methods are often used to analyze the influence of the deformation of strata and the land subsidence caused by dewatering on the surrounding buildings and underground pipelines (Zhou et al, 2010;Wang et al, 2013;Pujades et al, 2017;Wang et al, 2022). The deep foundation pit dewatering and ground settlement are efficiently analyzed via the water-soil coupling consolidation theory and three-dimensional finite element method.…”

Numerical Study on the Influence of Aquitard Layer Distribution and Permeability Parameters on Foundation Pit Dewatering

“…With the continuous development of modern civil engineering, the issue of excavation has become increasingly important, whether for urban construction or hydraulic engineering needs [1][2][3]. Excavation, especially the deep ones, is critical to the safety of structures.…”