摘要
为研究隧道开挖过程中临空面块体的稳定情况,进一步探究在其结构面具有胶结强度情况下块体的稳定性,运用黏聚力模型模拟具有填充和胶结的结构面的抗拉强度和黏聚强度,以及相应的滑移和脱开行为。选取甘肃北山某典型花岗岩研究区域搜索出的块体,以及获得的结构面参数区间,分4种方案研究块体的稳定性,同时考虑初始地应力、开挖诱导的二次地应力等因素的影响。方案1赋予抗拉强度和黏聚强度一个很小的数值,从而可以分析块体仅受结构面摩擦应力影响下的稳定性;方案2、3、4分别考虑不同位置的块体可能的失稳情况,通过调整不同块体结构面的抗拉强度和黏聚强度,分析块体稳定性。分析结果表明:黏聚力模型能较好地模拟具有填充和胶结的结构面的抗拉强度和黏聚强度,并且能模拟结构面的滑移和脱开行为,可作为块体稳定性分析计算的工具;此外,也为模拟胶结结构面损伤随时间的渐进性发展提供一个新思路。
The stability of the block of free face during tunnel excavation and the stability of the block under the condition of structural surface with cohesive strength are very important.Hence,the cohesive force model is used to simulate the tensile strength and cohesive strength of the filled and cemented structural surfaces and the corresponding sliding and detachment behaviors.The block selected from a typical granite area in Beishan,Gansu,as well as the structural surface parameter interval obtained are used to study the stability of block by 4 schemes;meanwhile,the influences of initial ground stress and secondary ground stress induced by excavation are considered.In scheme 1,the tensile strength and cohesion strength are given by a small value so as to analyze the stability of the block under the influence of friction stress on the structural surface.In the other three schemes,the possible instability of block at different positions is considered respectively,and the stability of the block is analyzed by adjusting the tensile strength and cohesive strength of different structural surface of block.The analytical results show that:the cohesive force model can simulate the tensile strength and cohesive strength of the filled and cemented structure surfaces commendably,and can simulate the sliding and detachment behavior of the structure surface as well,which can be used as a tool for block stability analysis and calculation;in addition,the results can provide a new idea to simulate the progressive development of cemented structural surface damage with time.
作者
骆健
章杨松
李晓昭
LUO Jian;ZHANG Yangsong;LI Xiaozhao(School of Science,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China;School of Earth Sciences and Engineering,Nanjing University,Nanjing 210093,Jiangsu,China)
出处
《隧道建设（中英文）》
北大核心
2018年第12期1975-1982,共8页
Tunnel Construction
基金
国防科技重点项目(科工二司[2015]297号)
国家重点基础研究发展计划(973计划)(2013CB036001)
关键词
隧道
黏聚力模型
胶结结构面
抗拉强度
黏聚强度
块体稳定性
tunnel
cohesive force model
cemented structural surface
tensile strength
cohesive strength
block stability
