文献类型：期刊文献

中文题名：基于小波分析的岩石节理剪切特性研究

英文题名：STUDY ON SHEAR BEHAVIOR OF WAVY ROCK JOINTS FROM WAVELET ANALYSIS

作者：李博[1];许久俊[1];钟杰[1];周宇[1];李迎春[2]

机构：[1]浙江省岩石力学与地质灾害重点实验室,绍兴文理学院,绍兴312000;[2]大连理工大学土木工程学院,大连116024

年份：2022

卷号：30

期号：3

起止页码：975

中文期刊名：工程地质学报

外文期刊名：Journal of Engineering Geology

收录：CSTPCD、、CSCD2021_2022、北大核心、CSCD、北大核心2020

基金：浙江省自然科学基金资助项目(资助号:LR19E090001);国家自然科学基金(资助号:42011530122,42077252)。

语种：中文

中文关键词：节理;一阶大起伏;二阶小凸起;剪切强度;小波分析法

外文关键词：Rock joint;First-order waviness;Second-order unevenness;Shear strength;Wavelet analysis

中文摘要：岩体工程中,节理面的轮廓特征是决定节理岩体剪切特性的重要因素,既往研究发现节理的表面轮廓可分解为一阶大起伏和二阶小凸起,且两者在剪切特性中发挥不同的作用。为了定量分析两阶表面特征对节理剪切强度的影响,本文通过小波分析法分解节理表面,并利用二维颗粒流数值模拟结合直剪试验验证,研究了具有不同起伏角(4°、8°、12°、16°、20°)波形节理面的细观破坏模式以及波面参数对剪切特性的影响规律。结果表明,波长对剪切强度影响较小,而起伏角是决定节理剪切强度的关键因素,随着起伏角增大剪切强度和摩擦角线性增大;直剪切过程中裂纹数量随法向应力的增大而增加,以拉伸裂纹为主;一阶大起伏与二阶小凸起的波形起伏角和摩擦角正相关。以上研究成果为预测节理岩体强度提供了理论支撑,对保障边坡、隧道等岩体工程的安全稳定性具有参考价值。

外文摘要：In rock engineering,the shear behavior of jointed rocks mainly depends on the surface characteristics of joints.It has been found that rock joint surfaces can be decomposed into a first-order waviness and a second-order unevenness,which play different roles in the shear behavior.To quantitatively estimate their influences,we first used wavelet analysis to decompose granite joints and red sandstone joints,then counted the wavelength and undulation angle of the waviness and unevenness.A reasonable parameter research scheme was designed to investigate the shear characteristics of the two types of joints.Based on the 3D printing technology,rock-like samples were prepared,and laboratory direct shear tests and two-dimensional particle flow code(PFC;)numerical simulations were conducted.To reliably replicate the mechanical behavior of jointed rocks,the parallel bond contact model was used to mimic the rock sample.The smooth-joint contact model was used to reproduce the rock joints with undulation angles of 4°,8°,12°,16°,and 20°.The meso-failure mode and shear mechanical properties of jointed rocks during the shear process were analyzed.The influence of the undulation angle and normal stress was revealed.The specific results and conclusions are as follows.(1)The unevenness model is less likely to crack under low normal stress.Under high stress,for the waviness and unevenness models with a larger undulation angle,the cracks gradually propagate to the deep part of the sample.For the waviness model under low normal stress and unevenness model under high stress,the cracks are mainly parallel to the shear direction.For the waviness model under high normal stress,the cracks far from the undulation toe are almost perpendicular to the uphill slope,while the cracks near the toe are almost parallel to the shear direction.(2)The tensile cracks dominate,accompanied by a small amount of shear cracks,the amount of cracks increases with the increasing normal stress.Fewer cracks were identified under low normal stresses.In the case of high normal stress,the number of cracks increases sharply.In addition,the shear strength of the waviness is higher than that of the unevenness with the same undulation angle and under the same normal stress.(3)The undulation angle and normal stress are the key factors determining the shear strength,and the influence of wavelength is negligible.The predicted empirical formula for shear strength of joints was established,which considers the undulation angleθ,the normal stressσ;,and the uniaxial compressive strength JCS:■.The model has been preliminarily verified through direct shear tests on jointed granite and red sandstone.(4)The relationship between the undulation angle and the friction angle of the waviness is y=0.7727x+12.88,and for the unevenness is y=0.706x+12.808.These findings provide theoretical support for predicting the strength of jointed rock masses,and are of significance for ensuring the safety and stability of rock engineering(e.g.,slope and tunnel).