文档介绍：软弱围岩隧道施工中的弹塑性数值模拟
陈瑛
(单位,中铁十一局一公司襄樊)
摘要: 以乔庄隧道的软弱围岩段实体建模,应用有限元程序对其施工全过程进行二维弹塑性数值模拟,得到了初期支护和二次衬砌等支护构件的受力和围岩位移收敛状况。另外,现场实际量测拱顶下沉和拱腰水平收敛值以及支护受力与计算数据的相互比较表明,两者变化规律吻合较好。说明采用现场动态监控量测与有限元仿真模拟相结合的方法可为隧道衬砌设计和施工的安全可靠性提供科学依据和技术指导。
关键词: 公路隧道;软弱围岩;动态监测;有限元模拟
中图分类号:U456 文献标识码:
Elastoplastic Numerical Calculating in Soft surrounding rock section During Construction process
Chen ying
(, Xiang fan 邮编, China)
Abstract: The tunnel in soft surrounding rock was modeled based on Qiaozhuang Tunnel, and two-dimensional elastoplastic numerical simulation is conducted for construction process. The convergence deformations of surrounding rocks, the stresses of initial and secondary lining are obtained. In addition, comparison of arch crown settlement, horizontal convergence of haunch and stress of lining between in-situ testing data puting ones shows that the variation laws fit preferably. These results shows that not only the in-situ dynamic measurements but also the analysis of FEM be important for essful construction of the tunnel under soft surrounding rock mass.
Key words:Highway tunnel; soft surrounding rock mass; dynamic monitoring; FEM simulation
0 引言
以新奥法修建的公路隧道中,隧道浅埋软弱段具有埋深浅、围岩稳定性差和受力复杂的特点,施工中稍有不慎就会造成围岩的过大变形而导致失稳。因此,对于隧道浅埋软弱段围岩在施工中的沉降及位移变化规律的研究非常重要[1-4]。而目前对此研究的方法有以下3种:现场量测方法;模型试验方法;数值模拟方法。3 种方法各有利弊,互为补充。本文以数值模拟为主,对隧道施工全过程进行模拟,同时结合现场实测数据对计算结果进行对比,以检验、分析结果的合理性。
1 工程地质概况
乔庄隧道为单向分