某重载铁路隧道地应力测试与反演分析

浩吉铁路如意隧道在施工期间部分段落出现拱顶开裂,初支混凝土剥落、掉块等破坏现象,初步认为与隧道所处地应力环境关系密切.为了准确掌握如意隧道围岩的初始应力状态和工程区地应力分布特征,在隧道内进行水压致裂地应力测试的基础上,采用有限单元法开展隧道三维地应力场回归反演分析.研究结果表明:(1)回归反演计算值与实测值之间的相对...

Measurement and Regression Analysis of the Tunnel Geostress of a Heavy Haul Railway

During the construction of Haolebaoji-Ji’an Railway,the cracking of arch crown,spalling of initial concrete and falling of blocks occurred in some sections of Ruyi tunnel.The preliminary analysis showed that the damages were closely related to the in-situ stress environment of the tunnel.In order to accurately grasp the initial stress state of surrounding rock of Ruyi tunnel and the characteristics of in-situ stress distribution,based on the in-situ test of hydraulic fracturing in the tunnel,the regression analysis of three-dimensional in-situ stress field of the tunnel was carried out by using the finite element method.The research results show that:(1)The relative error between the regression inversion calculation value and the measured value is less than 20%,and the inversion result of the in-situ stress field in the study area is reasonable;(2)the maximum in-situ stress in the section with prominent deformation and failure of Ruyi tunnel is less than 5 MPa.Due to the weak surrounding rock and large excavation section,the surrounding rock has extrusion deformation,it is necessary to take targeted prevention measures.