文献类型：期刊文献

中文题名：基于纳米划痕试验的砂岩结构面宏-微观摩擦系数关系研究

英文题名：Relationship between macro and micro friction coefficients of sandstone structural surface based on nano-scratch test

作者：郑爽[1];雍睿[1,2];杜时贵[1,2];何智海[1];钟祯[1];章莹莹[2];眭素刚[3]

机构：[1]绍兴文理学院土木工程学院,浙江绍兴312000;[2]宁波大学岩石力学研究所,浙江宁波315211;[3]中国有色金属工业昆明勘察设计研究院有限公司,云南昆明650000

年份：2023

卷号：44

期号：4

起止页码：1022

中文期刊名：岩土力学

外文期刊名：Rock and Soil Mechanics

收录：CSTPCD、、ESCI(收录号：WOS:000989320900009)、EI(收录号：20232314185741)、Scopus、CSCD2023_2024、WOS、北大核心、CSCD、北大核心2020

基金：This work was supported by the National Natural Science Foundation of China (42177117) and the Open Fund of Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province (ZJRMG-2018-Y-03).

语种：中文

中文关键词：摩擦系数;微观尺度;直剪试验;纳米划痕;RSF定律

外文关键词：friction coefficient;microscale;direct shear test;nano-scratch;RSF law

中文摘要：基本摩擦系数是影响岩体结构面抗剪强度的重要参数。常规室内试验方法所确定的基本摩擦系数往往受矿物成分、温度等因素影响,为系统揭示结构面的基本摩擦性质,分别研究了砂岩宏观摩擦系数与微观摩擦系数,并建立了两者的关系。首先,通过X射线衍射、纳米压痕试验确定砂岩矿物组分与力学参数。其次,采用倾斜试验、直剪试验开展摩擦系数的宏观尺度研究,对规格为10 cm×10 cm×5 cm的平直结构面试样开展直剪试验,分别施加1、2、3、8、12 MPa的恒定法向应力,研究表明,摩擦系数随法向应力增加呈对数降低趋势,随剪切速率增加呈对数增长趋势。再次,采用纳米划痕试验开展摩擦系数的微观尺度研究,研究表明,低荷载条件下,长石矿物摩擦系数随荷载增加表现出先降低后保持不变的趋势,石英矿物摩擦系数随荷载增加表现出先降低后增加的趋势;此外,随着剪切速率的增加,两种矿物的摩擦系数在低荷载条件下呈增长的趋势,在高荷载条件下基本保持稳定。最后,基于摩擦系数的宏-微观摩擦系数试验结果,采用速度-状态摩擦(RSF)定律建立红砂岩基本摩擦系数与矿物摩擦系数的线性回归方程,并通过直剪试验验证了该经验关系的可靠性,其误差范围为0.17%~0.91%。研究结果为基本摩擦系数的测定与取值提供了新思路。

外文摘要：Basic friction coefficients are important parameters affecting the shear strength of structural surface in rock masses. The basic friction coefficient determined by conventional laboratory test methods is influenced by mineral composition, temperature, and other factors. To systematically reveal the basic frictional properties of structural surfaces, the macro and micro friction coefficients of sandstone were investigated separately, and their relationship was established. First, mineral components and mechanical parameters of the sandstone were determined by X-ray diffraction and nanoindentation tests. Second, the friction coefficient in the macro scale was examined by tilt test and direct shear test, and the direct shear test was carried out on flat structural surface specimens dimensioning 10 cm×10 cm×5 cm subjected to constant normal stresses of 1, 2, 3, 8, and 12 MPa. The results show that the friction coefficient decreases in the logarithmic form as the normal stress rises, whereas it increases in the logarithmic form as the shear rate grows. Then, the friction coefficient in the micro scale was examined using nano-scratch test, and the results show that the friction coefficients of feldspar minerals first decrease and then remain unchanged with increasing load under low load conditions, and the friction coefficients of quartz minerals first decrease and then increase with increasing load. In addition, the friction coefficients of both minerals show an increasing trend with increasing shear rate under low load conditions, and remain stable under high load conditions. Finally, based on the macro-micro friction coefficient test results, the rate-and state-dependent friction(RSF) law was used to establish the linear regression equation linking the basic friction coefficient of red sandstone and the mineral friction coefficient, and the reliability of this empirical relationship was verified by the direct shear test with errors ranging from 0.17% to 0.91%. This study provides a new idea for the determination of the basic friction coefficient.