公路隧道最优开挖方法探讨分析  

Discussion and Analysis of the Optimal Excavation Method for Highway Tunnel

作　　者：徐东强[1] 张永潭 李晨 袁勇超[1] 

机构地区：[1]河北工业大学土木与交通学院,天津市300401 [2]中国建筑第六工程局有限公司,天津市300457

出　　处：《公路》2017年第5期242-248,共7页Highway

基　　金：河北省交通运输厅2013年度科研项目;项目编号201302025

摘　　要：结合隧道洞口过渡段不合理的开挖方式极易导致洞口段塌方的现状,以承赤高速公路第十九标段锥子山1号隧道右线工程为依托,通过FLAC^(3D)数值模拟的方法对V_2级围岩浅埋隧道采用单侧壁导洞法、预留核心土法、双侧壁导洞法、台阶法等4种开挖方法进行研究,通过对比分析隧道围岩位移与应力、衬砌结构位移与应力、塑性区体积,得出以下结论:单侧壁导洞法开挖会造成偏压,所得偏压量可为以后类似地质条件隧道开挖提供参考;开挖方法是否适合工程条件与其应力释放率大小及释放集中程度有直接关系,初步推断应力释放率有与围岩位移成正比、与围岩应力成反比的关系;双侧壁导洞法应力释放缓和,围岩、衬砌、锚杆位移与应力控制均是4种方法中最优的,塑性区发展控制也较为理想,认定为V_2级围岩浅埋隧道开挖最合理方法。In light of the fact that tunnel entrance transition section excavation means, with practical project of Zhuizishan No. 1 Tunnel on may easily collapse with improper Contract Section 19 of Chengde-Chifeng Expressway as background, the authors use the numerical simulation method of FLAC3D to study shallow tunnel in V2-Grade Rock, four excavation methods models are respectively established： the single- side Drift Law, core reserved earth Law, double side Drift Law, step method. By comparison and analysis of the displacement and stress of tunnel surrounding rock, displacement and stress of lining structure, the axial force of bolt, the plastic zone, etc. the following main conclusions are drawn： the single-side Drift Law will cause bias of rock, the obtained bias can provide reference for tunnel excavation with similar geological condition in the future; whether the excavation method is suitable for the engineering conditions is directly related to the stress release rate and the concentration degree of the stress release, it is preliminarily deduced that stress release rate is proportional to the displacement of surrounding rock, and inversely proportional to the stress of surrounding rock; and the double side Drift Law is regarded as the most reasonable construction method of shallow tunnel in V2-Grade Rock, because of its best control of displacement and stress of rock, lining, bolt and stress release rate, as well as development of plastic zone.

关 键 词：隧道 V2级围岩 开挖方法 应力释放 衬砌 分析 

分 类 号：U453.1[建筑科学—桥梁与隧道工程]