摘要
以沪昆高铁壁板坡特长隧道合分修段大跨断面为工程背景,应用MIDAS/GTS建立不同尺寸大跨断面以及高速铁路普通双线隧道断面的二维计算模型,对施工过程中围岩及支护结构力学特性进行了研究,并对比分析初支混凝土轴向应力计算值与实测值。结果表明:右上台阶施工是大跨断面采用中隔壁法开挖时决定隧道结构稳定的重要工序,断面尺寸是影响大跨断面围岩变形的主要因素,分步开挖、及时施作仰拱能有效改善大跨断面墙脚处应力集中、优化结构受力,保证围岩与支护结构的稳定。
Taking the large profile construction of forked part in the Bibanpo extra-long tunnel on Shanghai-Kunming high speed railway as the engineering background,2D numerical calculation model of tunnel sections with different large profile in common double lines of high speed railway was built to study the mechanical properties of surrounding rocks and supporting structures during the construction process and compare the calculated and measured values of initial supporting concrete axial stress by using MIDAS/GTS.The results show that the construction of right-upper bench is a decisive process for tunnel structure stability with large profile by CD excavation method,the section size is the main factor that affects the surrounding rock deformation of large profile tunnel,excavation by steps and inverted arch construction in time could improve the stress concentration at the wall foot of large profile,optimize the structure stress and ensure the stability of surrounding rock and supporting structure.
出处
《铁道建筑》
北大核心
2016年第10期55-58,共4页
Railway Engineering
关键词
高速铁路隧道
大跨断面
合分修
力学特性
数值计算
High speed railway tunnel
Large profile
Forked part
Mechanical properties
Numerical calculation
