不同卸荷速率条件下砂岩分级卸荷力学特性试验研究  

Experimental Study on the Mechanical Properties of Sandstone under Different Unloading Rates

作　　者：王旭 陈兴周[1] 张浩[2] 陈莉丽 杨冲 杜威 WANG Xu;CHEN Xingzhou;ZHANG Hao;CHEN Lili;YANG Chong;DU Wei(College of Architecture and Civil Engineering, Xi'an University of Science and Technology,Xi'an 710054;PowerChina Northwest Engineering Corporation Limited,Xi'an 710065)

机构地区：[1]西安科技大学建筑与土木工程学院,西安710054 [2]中国电建集团西北勘测设计研究院有限公司,西安710065

出　　处：《西北水电》2021年第5期21-25,共5页Northwest Hydropower

基　　金：国家自然科学基金项目(51979218、U1965107);陕西省自然科学基金项目(2018JM5188).

摘　　要：工程开挖活动是诱发隧洞围岩产生应力释放的主要因素,借鉴岩体结构力学和卸荷岩体力学思想,结合某隧道的场区环境,依托THMC多场耦合三轴试验系统开展了室内卸荷试验。考虑到隧洞开挖过程中,围岩总体存在上覆荷载变化较小,侧向约束迅速变小的受力特征,确定了轴压恒定与围压逐级减小的加卸载方式。结合工程分部开挖方式与强度诱导原岩应力释放,存在不同强度量级的现象,实施了考虑卸荷速率的分级卸荷试验。Engineering excavation is the main factor that induces stress release in the surrounding rock of the tunnel.With reference to the ideas of rock mass structural mechanics and unloading rock mass mechanics,combined with the field environment of a tunnel,the THMC multi-field coupled triaxial test apparatus is deployed to conduct indoor unloading test.Considering that the loading of the surrounding rock is featured by small changes in the overburden load and rapid reduction of lateral constraints during the tunnel excavation,the loading and unloading method with constant axial pressure and gradual decrease of confining pressure is determined.With consideration of the phenomena that the excavation method and intensity of divisional works inducing stress release of the original rock mass at various intensity levels,a graded unloading test considering the unloading rate is conducted.

关 键 词：隧洞开挖 卸荷岩体 分级卸荷 力学特性 

分 类 号：TD313[矿业工程—矿井建设]