摘要
节理粗糙度及吻合状态不仅直接影响节理力学性质,也对岩体的动态压缩性质有重要影响。首先采用水泥砂浆材料浇制不同粗糙度的完全吻合和不吻合节理岩体试样,然后使用分离式霍普金森杆系统对所制试样进行冲击试验研究节理岩体的动态压缩性质,同时利用高速摄像机及数字图像相关方法进行观测和计算去探究节理岩体动态破坏过程。结果表明:(1)给定冲击荷载下,节理面粗糙度对完全吻合型节理试样的动态压缩强度和平均模量影响不大,但对不吻合型节理试样影响较大;(2)不吻合型节理表现出非线性动态压缩闭合特点,其闭合特性不仅受到节理面粗糙度的影响,而且与节理的具体形貌特征相关;(3)应力波在通过完全吻合型节理岩体的能力时受到节理面粗糙程度的影响不大,而不吻合节理岩体试样则表现出随着JRC增大而增大的趋势;(4)节理岩体破坏与节理面的不规则凸起有关,节理壁凸起与应力波的相互作用引起节理面凸起处出现应力集中效应。拉应力引起张拉裂纹,而后裂纹扩展,直至贯通,岩体发生劈裂破坏坏。
The surface roughness and matching state of joints have an important influence on the dynamic mechanical properties of rock masses. This paper used cement mortar materials to make fully-matched and mismatched jointed samples with different roughness,and carried out impact tests on the samples by using the split Hopkinson pressure bar system(SHPB). At the same time,a high-speed camera and the digital image correlation method were used to explore the dynamic failure process of rock masses. The results show that,under a given impact load,the jointed roughness has little effect on the dynamic compressive strength and the average modulus of the fully-matched jointed rock-like specimens but has a greater influence on the mismatched jointed rock-like specimens. Mismatched joints exhibit nonlinear closure characteristics under stress wave,which is not only affected by the joint roughness but also related to joint specific morphological characteristics. With increasing the joint roughness,the ability of the stress wave to through the mismatched jointed rock mass increases,while the fully-matched jointed rock mass showed little effect. The failure of jointed rock mass is related to the irregular bulge of the joint surface. Specifically,The interaction between the stress waves and the bulge on the joint walls leads to the stress concentration in the vicinity of the bulge. The dramatical tensile stress initiates cracks,then these cracks develop,and splitting failure occurred.
作者
闫亚涛
李建春
YAN Yatao;LI Jianchun(School of Civil Engineering,Southeast University,Nanjing,Jiangsu 211189,China;Engineering Research Center of Safety and Protection of Explosion and Impact of Ministry of Education,Southeast University,Nanjing,Jiangsu 211189,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第6期1132-1144,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金杰出青年基金项目(41525009)
国家自然科学基金重点项目(41831281)
中央高校基本科研业务费专项资金项目(3205002010A2)。
作者简介
闫亚涛(1991-),男,2014年毕业于河南理工大学能源科学与工程学院,现为博士研究生,主要从事岩体动力学方面的研究工作。E-mail:ytyan@seu.edu.cn;通讯作者:李建春(1971-),女,博士,现任教授、博士生导师。E-mail:jcli@seu.edu.cn。
