软土蠕变对隧道结构荷载及变形的影响分析

摘要

软土的蠕变特性会削弱土拱效应,导致作用在隧道结构的土压荷载及隧道变形随时间发生变化.文章考虑软土的粘滞性,选取时间硬化法则与Druker-Prager屈服准则耦合的蠕变模型,结合上海地区软粘土的室内三轴流变试验数据,采用数值分析软件ABAQUS建立有限元模型,分析软土蠕变特性对隧道-地层接触压力的影响以及隧道的变形与内力等随时间的变化规律,并进一步探讨软土蠕变对土拱效应以及隧道长期受力性能的影响,研究结果对软土隧道设计中长期荷载的合理取值具有重要意义.%The creep property of soft soil can weaken the soil-arch effect, leading to the variation of the load and deformation of the tunnel lining with time. Considering the viscosity of soft soil, a creep model coupling with time hardening rule and the Druker-Prager yield criterion was adopted, and a finite-element model was established us-ing numerical analysis software ABAQUS to analyze the effect of soft soil creep on the contact pressure between the tunnel and stratum, tunnel deformation and internal force varying with time based on the data obtained from an in-door tri-axial rheological test of Shanghai soft soil. The influence of soft soil creep on the soil-arch effect and long-term mechanical properties of the lining is discussed in this paper.