基于土体刚度和蒙特卡洛法的基坑开挖对既有市政道路沉降影响分析

Analysis on Influence of Foundation Pit Excavation on Settlement of Existing Municipal Road Based on Soil Stiffness and Monte Carlo Method

摘要:

随着城市建设工程的持续增加，城市地下空间开发和市政设施建设产生的交叉也越来越多，许多基坑工程会在周边市政道路已经建成的条件下进行施工，基坑施工对既有市政道路产生一定的沉降影响，市政道路产生附加变形和附加应力降低了沥青路面的疲劳寿命。针对宁波市某基坑工程施工对近接市政道路的影响为工程背景，基于Plaxis数值模拟平台采用考虑小刚度的土体硬化本构模型，分析基坑的施工和简化的交通荷载对市政道路的受力变形的影响。在此基础上，采用蒙特卡洛法和数值模拟结果对道路结构层厚度进行随机选取，以沉降量为控制指标计算出疲劳寿命对该市政道路结构层给出了优化结果。

Abstract:

With the continuous increase of urban construction projects, there are more and more intersections in the development and construction of urban underground space and municipal facilities. Many foundation pit projects will be constructed under the condition that surrounding municipal roads have been built. The construction of foundation pit has a certain settlement impact on the existing municipal roads. The additional deformation and stress of municipal roads will reduce the fatigue life of asphalt pavement. Taking the influence of foundation pit construction on adjacent municipal road in Ningbo as the engineering background, based on Plaxis numerical simulation platform, the soil hardening constitutive model considering small stiffness is adopted to analyze the influence of foundation pit construction and simplified traffic load on the stress deformation of municipal road. On this basis, Monte Carlo method and numerical simulation results are used to randomly select the thickness of the road structure layer. The settlement is taken as the control index to calculate the fatigue life, and the optimization results are given for the municipal road structure layer.