隧道初期支护与微型桩组合结构CRD工法内力计算探讨  

Discussion on Internal Force Calculation of CRD Construction Method for Tunnel Initial Support and Micro-pile Composite Structure

作　　者：杨晔 Yang Ye(CCCC First Highway Consultants Co.,Ltd.,Xi'an,Shaanxi 710065)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710065

出　　处：《工程技术研究》2022年第19期10-12,74,共4页Engineering and Technological Research

摘　　要：文章依据高速公路三车道隧道Ⅴ级软弱松散围岩CRD工法,参照《公路隧道设计规范》(JTG 3370.1—2018)中有关深、浅埋隧道计算公式确定围岩压力,CRD工法中每个台阶初期支护每榀钢拱架均采用双层微型桩群桩约束墙脚,考虑与围岩的摩阻力并采用大型通用有限元程序计算结构内力。根据计算结果,支护与微型桩组合结构按照CRD工法,分步结构均可以承载60%~100%的围岩压力,相较传统规范CRD工法有了大幅提升。According to CRD construction method of grade V weak and loose surrounding rock of three-lane expressway tunnel, the surrounding rock pressure is determined with reference to the calculation formula of deep and shallow buried tunnels in Highway Tunnel Design Specification(JTG 3370.1-2018). In the CRD construction method, each steel arch frame of each step initial support adopts double-layer micro-pile group piles to restrain the foot of the wall. Considering the friction resistance with the surrounding rock, the large general finite element program is used to calculate the internal force of the structure. According to the calculation results, the support and micro-pile composite structure can bear 60%-100% of the surrounding rock pressure according to the CRD construction method, which is greatly improved compared with the traditional standard CRD construction method.

关 键 词：隧道初期支护 微型桩 组合结构 CRD工法 内力计算 

分 类 号：U455.7[建筑科学—桥梁与隧道工程]