堆载作用下地铁车站深基坑开挖模拟与实测数值分析

Numerical Simulation and Measurement Analysis of Deep Foundation Pit Excavation of Subway Station Under Surcharge

依托合肥市轨道交通5号线黄河路车站基坑工程,采用FLAC3D对其进行三维建模并计算,模拟将土方堆放在基坑两侧的工况,研究桩体侧向位移、结构内力等指标的变化情况,分析堆载对基坑稳定性的影响幅度,并将数值模拟结果与现场监测数据进行对比。结果表明:在相同的开挖深度下,堆载的存在对桩体侧向变形、桩体应力以及支撑轴力都产生了较大的影响。数值模拟结果与现场监测结果相应的分布规律和趋势一致,误差较小,能较为全面地反映基坑的变形特性。

Based on the foundation pit engineering of Huanghe Road Station of Hefei railway Line 5,FLAC3D is used to carry out 3D modeling and calculation.The working condition of stacking earthwork on both sides of the foundation pit is simulated.The changes of lateral displacement piles,internal force and other indicators are studied,and the influence of the surcharge on the stability of the foundation pit is analyzed.The numerical simulation results are compared with the field monitoring data.The results show that:at the same excavation depth,the pile lateral deformation,pile stress and supporting axial force are greatly affected by the surcharge.The numerical simulation results are consistent with the distribution laws and trend of the field monitoring results,thus can comprehensively reflect the deformation characteristics of the foundation pit.