摘要
支护体系是隧道稳定性的保障,支护体系的合理性应根据隧道的围岩条件、地形条件、水文条件和施工工法等来进行判断。依托某软弱围岩连拱隧道工程,借助大型有限差分软件FLAC3D模拟不同支护参数下隧道开挖施工,研究分析在不同支护参数下隧道围岩变形规律及结构受力特征,最终比选出连拱隧道最为合理的支护参数。研究结果表明,不同初支厚度下结构内力分布规律基本一致,拱顶处初支受拉最大,拱肩处初支受压最大,当支护厚度由30 cm增加到40 cm时,初支受压由13.5 MPa减小到12.4 MPa,虽然初支厚度的增加可削弱应力集中现象,但改善效果并不明显。同时,不同初支厚度下围岩位移变化历程基本一致,拱顶处出现最大沉降,拱腰处出现最大水平收敛,随着初支厚度的增加,围岩位移略有减小,但减小幅度不大。综合考虑施工安全和经济性,最终选择30 cm厚初喷混凝土。
The support system is the guarantee of the stability of the tunnel.The rationality of the support system should be judged according to the surrounding rock conditions,terrain conditions,hydrological conditions and construction methods of the tunnel.Based on a multi-arch tunnel project with weak surrounding rock,this paper simulates the tunnel excavation construction under different supporting parameters with the help of large-scale finite difference software FLAC 3D,studies and analyzes the deformation law and structural stress characteristics of tunnel surrounding rock under different supporting parameters,and finally selects the most reasonable supporting parameters of multi-arch tunnel.The results show that the internal force distribution of the structure under different initial support thicknesses is basically the same.The initial support at the vault is the largest in tension,and the initial support at the arch shoulder is the largest in compression.When the support thickness increases from 30 cm to 40 cm,the initial support compression decreases from 13.5 MPa to 12.4 MPa.Although the increase of the initial support thickness can weaken the stress concentration phenomenon,the improvement effect is not obvious.At the same time,the displacement history of surrounding rock under different initial support thicknesses is basically the same.The maximum settlement occurs at the vault and the maximum horizontal convergence occurs at the arch waist.With the increase of initial support thickness,the displacement of surrounding rock decreases slightly,but the decrease is not large.Considering the construction safety and economy,the initial shotcrete with a thickness of 30 cm was finally selected.
作者
肖杨
蒲松
Xiao Yang;Pu Song(Chongqing Survey and Design Institute Co.,Ltd.,Chongqing 400023,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China)
出处
《山西建筑》
2023年第20期153-156,共4页
Shanxi Architecture
关键词
软弱围岩
连拱隧道
数值分析
力学特性
支护参数
weak surrounding rock
double-arch tunnel
numerical analysis
mechanical properties
support parameters
作者简介
肖杨(1989-),男,硕士,工程师,从事隧道工程方面的研究。
