摘要
岩石结构面表面形貌由宏观起伏体(一级)和表面微凸体(二级)两级形貌共同组成,剪切过程中各级形貌的剪切特性不尽相同。结合三维激光扫描技术、3D打印技术和模拟材料批量制作了模型结构面,开展了不同法向应力条件下的直剪试验。试验结果表明:相同法向应力条件下,二级形貌剪切磨损接近总体形貌,且大于一级形貌;不同法向应力条件下,剪切前后两级粗糙参数平均变化率随法向应力增加而逐渐增加,其中一级粗糙参数平均变化率ηI为1.99%~4.03%,二级粗糙参数平均变化率η为5.97%~8.16%;进一步基于“余弦相似性”原理计算余弦夹角以评价剪切前后结构面形貌相似性,发现二级形貌余弦夹角波动最大,一级形貌余弦夹角与总体形貌余弦夹角较接近,验证了二级形貌的剪损特性和一级形貌的剪胀特性。上述研究可为结构面抗剪强度的评价提供参考意义。
The surface morphology of rock joints is composed of two-order morphology, including macroscopic undulation components(first-order) and asperities of joint surfaces(second-order), and different morphologic components contribute differently to the shear characteristics during the shearing process. 3D laser scanning, 3D printing technology and similar materials are adopted to produce different model joints in batches, and direct shear tests are carried out under different normal stress conditions. The test results show that under the same normal stress, the second-order morphology shear wear is close to the overall morphology and greater than the first-order morphology. Under different normal stresses, the average variation rate of the two-order roughness parameters gradually increases with the increase of the normal stress before and after shearing. The average variation rate of the first-order roughness parameters ηI is 1.99%~4.03%, and that of the second-order roughness parameters ηis 5.97%~8.16%. The cosine angle is calculated based on the principle of "cosine similarity" to evaluate the similarity of the joints before and after shearing. The cosine angle of the second-order morphology fluctuates most, the cosine angle of the first-order morphology is close to the overall morphology, and the shear wear characteristics of the second-order morphology and the shear dilatancy characteristics of the first-order morphology are verified. The above results are of reference significance for the evaluation of the shear strength of joints.
作者
刘丹
张博文
洪陈杰
黄曼
杜时贵
罗战友
LIU Dan;ZHANG Bo-wen;HONG Chen-jie;HUANG Man;DU Shi-gui;LUO Zhan-you(School of Civil Engineering,Shaoxing University,Shaoxing 312000,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Civil Engineering and Environment,Ningbo University,Ningbo 315000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2022年第8期1434-1442,I0005,I0006,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(41427802,41572299)
浙江省自然科学基金项目(LY18D020003)。
关键词
岩石结构面
两级形貌
两级粗糙参数
直剪试验
剪切特性
rock joint
two-order morphology
two-order roughness parameter
direct shear test
shear property
