锚固的双重孔隙–裂隙岩体流变模型及其地下洞室二维有限元分析  

A bolted rheological model for dual-pore-fracture rock mass and 2D FEM analyses for underground cavern

作　　者：张玉军[1] 张维庆 ZHANG Yujun;ZHANG Weiqing(State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China;China Railway Tunnel Survey and Design Institute Co., Ltd., Tianjin 300133, China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中铁隧道勘测设计院有限公司,天津300133

出　　处：《岩石力学与工程学报》2018年第A01期3300-3309,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51379201);国家重点基础研究发展计划(973)项目(2010CB732101)~~

摘　　要：针对所提出的双重孔隙–裂隙介质西原流变模型,建立相应的锚固体模型,给出将锚杆材料的弹性模量、抗剪强度等效均化到锚固体中的数学表达式。模拟一个假定的矩形地下洞室,就毛洞、使用不同厚度的锚固单元和杆单元的工况,进行二维有限元计算,分析、对比围岩中的位移、应力及塑性区。其结果显示:系统锚杆对洞周位移有一定约束作用,但不与其长度成正比,与杆单元相比锚固单元对位移的约束作用要明显;锚固区有明显的应力集中现象,而随锚杆长度的增加围岩中应力分布及量值也有一定的变化;系统锚杆使得围岩中的塑性区明显减小,但其作用也不与其长度成正比;而对同样长度锚杆分别使用锚固单元和杆单元时,所得的塑性区面积接近,但分布形状有所不同。Aiming at Nishihara model to describe the rheological characteristics of dual-pore-fracture media suggested by the author,a corresponding bolted body model was established,and the mathematical expressions were given for distributing uniformly the elastic modulus and shearing strength of bolt material into the bolted body. Simulating a hypothetical rectangular underground cavern,the 2 D FEM analysis were carried out on the cases of cavern without bolting and with bolted body elements as well as with bar elements,respectively,and the displacements,stresses and plastic zones in the surrounding rock mass were analyzed and compared. The results show that the systematic bolting has certain restriction on the displacements of cavern boundary,but this effect is not proportional to the bolt length,and it is more obvious for the case with bolted body elements than for that with bar elements;there are obvious stress concentration phenomena in the bolted zones,and the distributions and values of stresses in the surrounding rock also have some changes with increase of the bolt length;the systematic bolting makes the plastic zones in the surrounding rock decrease obviously,but this effect also is not proportional to the bolt length;using bolted body elements and bar elements for the bolts with same length respectively,the areas of plastic zones obtained are close to each other,but the distribution shapes have some differences.

关 键 词：数值分析 双重孔隙–裂隙岩体 黏弹塑性 锚固体模型 地下洞室 有限元分析 

分 类 号：O241[理学—计算数学]