盾构隧道对邻近建筑桩基影响的时间相关性

Time Dependence of Shield Tunnel on Adjacent Pile Foundation

引入等代层的概念,并将扰动区土体处理为粘弹性介质,采用数值模拟的方法分析了盾构隧道施工后对邻近建筑物桩基的时间相关性影响。建立了隧道和邻近建筑及其桩基的力学计算模型,通过对特征时刻的桩基水平位移值的研究,分析了既有隧道和邻近建筑各计算参数对桩基的影响。研究表明,盾构隧道对邻近建筑物及桩基的影响是时间相关的,隧道在开挖后一段时间内对周边建筑及桩基产生影响,其影响时间的长短与周边土体的粘弹性性质以及隧道和邻近建筑的参数有关。

By introducing in the concept of equivalent substitute layer, in which the soil is counted as a viscoelastic mass, the time dependence effect of shield tunnel on the adjacent building＇s pile foundation is analyzed through numerical method. Thus the mechanics model of shield tunnel and the adjacent pile foundation are set up. By studying the horizontal displacement values of the pile foundation at characteristic times, the effect of computation parameters of the existing tunnel and adjacent building is also analyzed. This research shows that the effect of shield tunnel on the adjacent building＇s pile foundation is time dependent, because the adjacent structure and the pile foundation are affected in a certain period of time even after the shield was excavated, and this affected time is related to the viscoelastic property of soil, the parameters of the existing tunnel and structure.