公路隧道通风竖井岩爆机制颗粒流模拟研究  

Particle flow simulation of rock burst mechanism for highway tunnel ventilation shaft

作　　者：徐士良[1,2,3] 朱合华[2,3] 

机构地区：[1]安徽建筑工业学院岩土工程系,合肥230022 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]同济大学地下建筑与工程系,上海200092

出　　处：《岩土力学》2011年第3期885-890,898,共7页Rock and Soil Mechanics

摘　　要：根据工程地质资料分析,岩爆是秦岭公路隧道2号通风竖井施工过程中的主要难题。岩爆机制是指岩爆发生的物理过程,与岩石的颗粒大小、颗粒胶结和粒间孔隙等结构特征密切相关。根据颗粒流基本理论和竖井混合片麻岩的基本力学特性,进行混合片麻岩细观颗粒参数标定研究。颗粒大小不是一个自由参数,通过颗粒流模拟的相似比分析,采用强度折减方法进行竖井岩爆机制的颗粒流模拟。研究表明,岩爆孕育的细观机制为平行于开挖面的微裂纹萌生—微裂纹扩展、聚合—宏观裂纹的形成,为压致张剪断裂破坏,主要是由张拉裂纹扩展、聚合引起的,是一个渐近破坏过程。研究成果为竖井岩爆稳定性分析提供初步依据。Rock burst is a serious problem during the excavation process of the ventilation shaft No.2 of Qinling highway tunnel according to the analysis of in-situ engineering geological condition.Rock burst mechanism is a physical process related to the rock microstructure including particle diameter,particle cement and particle void,etc.The microscopic parameters of mixed gneiss are calibrated based on the theory of particle flow and basic macroscopic mechanic properties of mixed gneiss.The analysis of similarity criteria about particle flow simulation is conducted because particle diameters are not free parameters and then the rock burst mechanism is simulated using particle mechanics approach and strength reduction method.The results show that the rock burst mechanism is a progressive failure process including crack initiation,crack propagation,crack coalescence and formation of macroscopic fracture.The failure type is compression-induced tensile-shear failure;and it is dominantly tensile cracking.The results provide preliminarily references for stability analysis of rock burst of ventilation shaft.

关 键 词：岩爆机制 颗粒流 离散元 隧道工程 通风竖井 

分 类 号：TU452[建筑科学—岩土工程]