分层降水及极端降雨条件下基坑围护结构及邻近公路路基变形规律研究

陈旺; 于朝阳; 陈建清; 朱超; 庄妍

doi:10.13928/j.cnki.wrahe.2025.11.017

水利水电技术（中英文） ›› 2025, Vol. 56 ›› Issue (11) : 213 -229. DOI: 10.13928/j.cnki.wrahe.2025.11.017

工程地质

分层降水及极端降雨条件下基坑围护结构及邻近公路路基变形规律研究

陈旺 ¹^,²^,³ ,
于朝阳 ¹^,²^,³ ,
陈建清 ¹^,² ,
朱超 ¹^,²^,³ ,
庄妍 ⁴^,⁵

作者信息 +

Research on the deformation response analysis of foundation pit retaining structure and adjacent highway subgrade under stratified dewatering and extreme rainfall conditions

Wang CHEN ¹^,²^,³ ,
Chaoyang YU ¹^,²^,³ ,
Jianqing CHEN ¹^,² ,
Chao ZHU ¹^,²^,³ ,
Yan ZHUANG ⁴^,⁵

Author information +

文章历史 +

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摘要

【目的】为探究极端降雨条件下基坑分层降水对基坑围护结构及临近公路路基稳定性的影响，【方法】基于盐城市铁路客运枢纽深基坑工程构建三维有限元分析模型，并采用现场实测数据验证模型的准确性；通过系统分析基坑分层降水及开挖过程中基坑围护结构的侧移量、混凝土支撑的支撑轴力及临近公路路基沉降量的变化规律，揭示了基坑分层降水及极端降雨条件对基坑围护结构侧移量及临近公路路基沉降量的影响规律。【结果】结果表明：考虑基坑分层降水条件下墙体的最大侧移量比未考虑时增加了约7%~45%,墙体最大弯矩增加了约5%~13%;在开挖过程中未考虑基坑分层降水的路基表面沉降量显著小于考虑基坑降水条件下路基表面的沉降量；当降雨条件由大雨(28.15 mm/d)增至大暴雨(100.80 mm/d)时基坑围护结构侧移量增加了约40%,当降雨条件由暴雨(50.00 mm/d)增至大暴雨(100.80 mm/d)时路基坡脚和坡肩处的最大水平位移分别增加了约35%和142%;在极端降雨条件下(100.80 mm/d)随着墙体嵌入深度的增加，墙体最大侧移量降幅由13%降至6%,路基边坡各区域的最大水平位移均呈逐渐减小的变化规律。随着内支撑水平距离的减小，墙体的大侧移量降低约9%,路基的边坡最大位移量降低约11%。【结论】极端降雨条件下基坑分层降水对基坑围护结构及临近公路路基的稳定性均具有显著影响，建议在深基坑施工过程中(尤其是在雨季)适当增加基坑围护结构的嵌入深度或减小内支撑的水平间距，可实现较好的控制基坑围护结构及邻近建筑物的稳定性。

Abstract

[Objective] To investigate the impact of stratified dewatering in a foundation pit under extreme rainfall conditions on the stability of the foundation pits retaining structures and the adjacent road embankment, [Methods]a three-dimensional finite element analysis model was constructed based on the deep foundation pit project of the Yancheng Railway Passenger Hub. The accuracy of the model was validated using field measurement data. By systematically analyzing the variation patterns of lateral displacement of the retaining structures, axial force of the concrete supports, and settlement of the adjacent road embankment during the stratified dewatering and excavation processes, the influence of stratified dewatering and extreme rainfall conditions on the lateral displacement of the retaining structures and the settlement of the adjacent road embankment was revealed. [Results] The results show that, under stratified dewatering conditions, the maximum lateral displacement of the retaining walls increased by approximately 7% to 45%, and the maximum bending moment increased by about 5% to 13% compared to the scenario without considering stratified dewatering. During the excavation process, the surface settlement of the road embankment without considering stratified dewatering was significantly smaller than that with stratified dewatering. When the rainfall condition increased from heavy rain(28.15 mm/d) to heavy downpour(100.80 mm/d), the lateral displacement of the retaining structures increased by about 40%. When the rainfall condition increased from heavy rain(50.00 mm/d) to heavy downpour(100.80 mm/d), the maximum horizontal displacements at the toe and shoulder of the road embankment slope increased by about 35% and 142%, respectively. Under extreme rainfall conditions(100.80 mm/d), as the embedment depth of the wall increased, the reduction in the maximum lateral displacement of the wall decreased from 13% to 6%, and the maximum horizontal displacements in various regions of the road embankment slope showed a gradually decreasing trend. As the horizontal distance of the internal supports decreased, the large lateral displacement of the wall reduced by about 9%, and the maximum displacement of the road embankment slope decreased by about 11%. [Conclusion] Stratified dewatering in foundation pits under extreme rainfall conditions has a significant impact on the stability of the retaining structures and the adjacent road embankment. It is recommended to appropriately increase the embedment depth of the retaining structures or reduce the horizontal spacing of the internal supports during deep foundation pit construction, especially during the rainy season, to achieve better control over the stability of the retaining structures and adjacent buildings.