不同埋深盾构隧道开挖面稳定问题数值模拟

发布时间：2018-01-06 00:05

本文关键词：不同埋深盾构隧道开挖面稳定问题数值模拟　出处：《东南大学学报(自然科学版)》2017年01期 　论文类型：期刊论文

【摘要】：通过对照物理模型试验,采用二维颗粒流程序(PFC2D)对不同埋深和不同密度条件下的盾构掘进过程进行数值模拟,从而分析开挖面前方土体破坏机理.首先通过研究支护力和地表沉降的变化规律,将模型箱试验结果和数值模拟结果进行对比分析,分别确定了极限支护力;利用二维颗粒流程序对土拱效应进行研究,揭示了开挖面前方土体的失稳破坏机理.结果表明,支护力和地表沉降的变化规律都可分为2个阶段,且不受埋深条件的影响;发生局部失稳破坏后,土拱继续向上发展最终导致整体失稳破坏;埋深比较小时,未能形成土拱,而埋深比较大时,滑动区与土拱区随埋深比的增大而增大.数值模拟结果与模型箱试验结果基本一致,验证了采用纵面进行颗粒流模拟的可行性,因此可利用PFC2D进行深入颗粒流模拟.
[Abstract]:Through the control of the physical model test, using two-dimensional particle flow code (PFC2D) numerical simulation of shield tunneling process in different depth and different density conditions, so as to analyze the failure mechanism of soil before the excavation face. Firstly, the change law of supporting force and the surface subsidence, the model test results and numerical simulation results are compared analysis, determined the limit support pressure; flow on the soil arching effect is studied by using two-dimensional particle, reveals the soil before the excavation face failure mechanism. The results show that the variation of supporting force and ground settlement can be divided into 2 stages, and is not affected by the buried condition occurred; the local buckling, soil arching to development eventually lead to global instability; the depth is small, failed to form a soil arch, and the buried depth is large, the sliding area and soil arching region with depth ratio increased The numerical simulation results are basically consistent with the model box test results, which verifies the feasibility of particle flow simulation with longitudinal surfaces. Therefore, PFC2D can be used for in-depth particle flow simulation.

【作者单位】：东南大学岩土工程研究所;
【基金】：国家自然科学基金资助项目(51578147,51278099)
【分类号】：U455.43
【正文快照】： 近年来,盾构施工技术由于具有施工机械化程度高、对周围环境影响小、施工快速等优势得到了广泛应用[1].施工时,既要保持开挖面稳定性,还要在控制地基的沉降同时避免支护力过小造成的前方土体过大沉降(甚至坍塌)和支护力过大可能导致的地表隆起.周小文等[2]针对开挖面稳定问题

【相似文献】