动静荷载下层状围岩隧道应力集中分布特征  

Characteristic of stress concentration distribution in layered rock of tunnel under dynamic and static load

作　　者：杨玉民 蒋楠 姚颖康 周传波[1] 蒙贤忠 赵茉溪 YANG Yumin;JIANG Nan;YAO Yingkang;ZHOU Chuanbo;MENG Xianzhong;ZHAO Moxi(Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Precision Blasting,Jianghan University,Wuhan 430056,China;Hubei Key Laboratory of Blasting Engineering,Jianghan University,Wuhan 430056,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]江汉大学省部共建精细爆破国家重点实验室,湖北武汉430056 [3]江汉大学爆破工程湖北省重点实验室,湖北武汉430056

出　　处：《浙江大学学报(工学版)》2025年第2期319-331,401,共14页Journal of Zhejiang University:Engineering Science

基　　金：国家自然科学基金资助项目(42102329,52478525);湖北省自然科学基金杰出青年资助项目(2024AFA092);湖北省重点研发计划资助项目(2021BAD004);武汉市重点研发计划资助项目(2024050802030155).

摘　　要：针对圣加旺水电站层状围岩引水隧道工程,设计物理模型相似试验,考虑不同的静荷载、动荷载及围岩倾角,采用LSDYNA分析层状岩体应力波的传播特性及分布特征.通过正交试验分析不同因素对围岩峰值应力及二次平衡应力的敏感性,基于量纲分析建立多因素影响下应力预测模型,确定围岩安全荷载控制范围.结果表明,高地应力条件下隧道围岩存在初始应力集中,动力扰动对应力集中数值的影响显著,应力波波阵面受层理的影响呈不连续分布.动、静载与围岩峰值应力、二次平衡应力呈正线性相关,围岩峰值应力及二次平衡应力随倾角增大呈“∧”型分布,不同因素对围岩峰值应力及二次平衡应力的敏感性顺序均为动载>静载>倾角.当围岩倾角为90°(0°)、75°(15°)、60°(30°)及45°时,静载极限值分别为0.731、0.555、0.479及0.456 MPa,动载极限值分别为0.624、0.523、0.477及0.463 MPa.The similar test of physical model was designed aiming at the diversion tunnel project of layered surrounding rock of San Gavan Hydropower Station.LSDYNA was used to analyze the propagation characteristics and distribution characteristics of stress wave in layered rock mass by considering the static load,dynamic load and the dip angle.The sensitivity of different factors to the peak stress and secondary equilibrium stress of surrounding rock was analyzed by orthogonal test.A stress prediction model under the influence of multiple factors was established based on the dimensional analysis in order to determine the safety load control range of surrounding rock.Results showed that there was initial stress concentration in the surrounding rock of tunnel under high ground stress.The dynamic load had a significant impact on the value of stress concentration.The stress wave front was discontinuously distributed due to the influence of bedding.The dynamic and static loads were positively linearly correlated with the peak stress and secondary equilibrium stress.The peak stress and secondary equilibrium stress showed'∧'type distribution with the increase of dip angle.The sensitivity order of different factors to the peak stress and secondary equilibrium stress was dynamic load>static load>dip angle.The static load limit values were 0.731,0.555,0.479 and 0.456 MPa respectively,and the dynamic load limit values were 0.624,0.523,0.477 and 0.463 MPa respectively when the dip angle was 90°(0°),75°(15°),60°(30°)and 45°.

关 键 词：动静荷载 层状岩体 应力集中 量纲分析 安全控制 

分 类 号：U45[建筑科学—桥梁与隧道工程]