摘要
颗粒材料系统在剪切过程中存在应力突变的情况,为了探究颗粒材料在剪切过程中的宏观力学响应与其细观参数的内在联系,通过室内直剪试验,研究了颗粒材料系统在受压剪作用下的粘滑(stick-slip)行为。将玻璃微珠作为颗粒材料进行了不同正应力下的直剪试验,并引入率态摩擦模型(RSF)对试验结果进行了定量分析,通过强度阶跃试验得到了率态摩擦模型相关参数。试验结果表明:(1)不同正应力下的粘滑曲线变化趋势基本相同,并呈现周期性的规律,但粘滑导致的应力降和周期随正应力的减小而减小;(2)在施加的压力范围内,通过计算得到其刚度比κ均小于1,且κ随正应力的增大而减小,这说明该颗粒材料满足失稳判据,试验现象与理论预测相符。成果为研究地震发生机理提供了思路,据此可推测断层的粘滑失稳及地震发生是由于断层面的滑移速度瞬时改变引起的,κ值越小其峰值粘滑速率越大,同时产生的应力降和粘滑周期越大。
In order to explore the internal relationship between the macro mechanical response of granular materials in the shear process and their micro parameters,the stick-slip behavior of granular materials under compression and shear was studied through indoor direct shear test.Glass beads were used as granular materials to conduct direct shear test under different normal stresses,and the rate state friction model(RSF)was introduced to quantitatively analyze the test results,and the relevant parameters of the rate state friction model were obtained through the strength step test.The experimental results show that:(1)the variation trend of the stick-slip curve under different normal stresses is basically the same and shows a periodic pattern,but the stress drop and period caused by stick-slip decrease with the decrease of normal stress;(2)within the applied pressure range,the stiffness ratioκis calculated to be less than 1,andκdecreases with the increase of normal stress.This indicates that the granular material meets the instability criterion,and the experimental phenomenon is consistent with theoretical predictions.This provides ideas for studying the mechanism of earthquake occurrence,and based on this,it can be inferred that the stick-slip instability of faults and the cause of earthquakes are caused by the instantaneous change of slip velocity at the fault plane.The smaller theκvalue,the greater the peak stick-slip rate,and the greater the stress drop and stick-slip period generated.
作者
刘建生
熊文勇
邓翔浩
傅力
童立红
Liu Jiansheng;Xiong Wenyong;Deng Xianghao;Fu Li;Tong Lihong(Jiangxi Transporation Engineering Group Co.,Ltd.,Nanchang 330028,Jiangxi,China;Jiangxi Intelligent Maintenance Engineering Technology Research Center of Bridge,Nanchang 330028,Jiangxi,China;Institute of Geotechnical Engineering,School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,Jiangxi,China)
出处
《岩土工程技术》
2023年第4期449-454,共6页
Geotechnical Engineering Technique
基金
江西省交通运输厅科技项目(2021H0004)
江西省教育厅课题(GJJ210618)
江西省科技合作专项项目(20212BDH81034)。
关键词
颗粒材料粘滑现象
直剪试验
速率状态摩擦模型
失稳破坏模式
particle stick-slip phenomenon
direct shear test
rate state friction model
instable destruction mode
