半明半暗隧道洞口段力学特征分析与现场监测  

MECHANICAL CHARACTER ANALYSIS AND IN-SITU MONITORING FOR PORTAL SECTION OF HALF-BURIED TUNNEL

作　　者：伍毅敏[1] 王飞[2] 邹正明[3] 吕康成[1] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]安徽省交通规划设计研究院,安徽合肥230041 [3]安徽省交通投资集团,安徽合肥230011

出　　处：《岩石力学与工程学报》2008年第S1期2873-2882,共10页Chinese Journal of Rock Mechanics and Engineering

摘　　要：由于结构复杂和荷载多变,不同条件下的半明半暗隧道洞口段在各施工阶段的力学行为差异很大,给施工和监控带来很大困难。根据洞口段结构承受水平荷载和垂直荷载的比重不同,将半明半暗洞口分为受推型、受压型和推压组合型3类。应用有限元软件对3类结构进行数值模拟,研究不同条件下半明半暗洞口的位移和应力分布规律,得到其在不同施工阶段的受力变形特征,掌握各类结构在不同施工阶段的薄弱部位,并提出监测要点。根据研究得出的监测要点,对4处实体工程进行现场监测,结果表明:(1)结构的实际位移和应力分布与理论分析结果相符;(2)结构破坏部位和破坏形式与理论分析相符;(3)根据相应结构类型的受力变形机制选取合理处治措施,能够有效地控制结构异常变形。研究结果可供类似工程设计、施工和现场监测参考。Due to the complicated structure and the influence of multiple disturbance of surrounding rock in period of construction,the mechanical behaviors of portal section of half-buried tunnel differ greatly in different construction stages,which brings great difficulties to construction and monitoring. According to the proportion of horizontal and vertical loads borne by the structure,the portal of the half-buried tunnels is divided into three types,i.e. thrust portal,compression portal and combined thrust-compression portal. Numerical simulation is carried out to research the distribution and the developing law of displacement and stress under different conditions. By analyzing the mechanical characters,the weakest positions are detected and the essential monitoring items are also listed in different stages of construction for different types of structures. Based on these results,in-situ monitoring is carried out in four actual highway tunnel engineering. In-situ monitoring results indicate that:(1) the distribution and the developing law of displacement and stress agree with the theoretical results perfectly;(2) the positions and failure modes of structures accord with the theoretical results;and (3) abnormal deformation of structures can be effectively controlled by adopting reasonable measures according to the deformation mechanism of corresponding structure under load. The presented conclusions can provide references for design,construction and in-situ monitoring of similar tunnels.

关 键 词：隧道工程 洞口 半明半暗隧道 力学分析 现场监测 

分 类 号：U451[建筑科学—桥梁与隧道工程] U456.3[交通运输工程—道路与铁道工程]