充填岩石节理剪切力学特性及强度经验公式研究  

Shear mechanical properties and empirical formula of infilled rock joints

作　　者：高福洲 张俊云[1] 罗晓龙 翟恪祥 张乐 黄锐[1,2] 武小菲 GAO Fuzhou;ZHANG Junyun;LUO Xiaolong;ZHAI Kexiang;ZHANG Le;HUANG Rui;WU Xiaofei(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Highway Planning Survey and Design Institute Ltd.,Chengdu 610041,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]四川省公路规划勘察设计研究院有限公司,四川成都610041

出　　处：《岩土工程学报》2025年第3期608-617,共10页Chinese Journal of Geotechnical Engineering

基　　金：四川省交通运输科技项目(2021-A-02);四川省科技计划项目(2021YFS0321)。

摘　　要：研究充填岩石节理的剪切力学特性对工程岩体的稳定性评价具有重要意义。为此,开展考虑法向应力σ_(n)、充填厚度t、节理粗糙度系数JRC影响下的充填岩石节理大型直剪试验,分析了剪切破坏特征、剪切特征曲线和峰值剪切强度τ_(p)的演化规律,在此基础上建立了充填岩石节理峰值剪切强度经验公式。研究表明:充填岩石节理的剪切破坏位置以充填介质与节理岩壁接触面破坏为主;其剪切应力-剪切位移曲线通常在σ_(n)≥600k Pa,t≤5mm且JRC≥6.36条件下出现剪切应力峰值点;在充填度Δ=1.12时充填岩石节理峰值剪切强度τ_(p)与充填介质剪切强度τ_(i)相近,随着Δ进一步增大,τ_(p)降低至τ_(i)以下;充填岩石节理峰值剪切强度经验公式中引入描述充填介质与节理岩壁接触面相互作用对τ_(p)影响的参数W,公式计算值与试验值相对误差平均值δ≤9.01%。The investigation of the shear mechanical properties of infilled rock joints is of significant importance for the stability assessment of engineering rock formations.In this study,the large-scale direct shear tests on infilled rock joint specimens are conducted considering the influences of normal stress(ns),infilled thickness(t)and joint roughness coefficient(JRC).The evolution patterns of the shear failure characteristics,shear characteristics curves and peak shear strength are analyzed.Based on these findings,an empirical formula for the peak shear strength of infilled rock joints is established.The study reveals that the shear failure location of the infilled rock joint is primarily at the contact interface between the infilled medium and the rock joint wall.The shear stress-shear displacement curve of the infilled rock joint typically exhibits a shear stress peak when σ_(n)≥600 kPa,t≤5 mm,and JRC≥6.36.At an infilled ratioΔof 1.12,the peak shear strength of the rock joint(τ_(p))is close to that of the infilled medium(τ_(i)),AsΔfurther increases,τ_(p)decreases below τ_(i).The parameter W is introduced into the empirical formula for the peak shear strength of the infilled rock joint to describe the interaction occurring at the contact surface between the infilled medium and the rock joint wall,capturing the influences on the peak shear strength of the infilled rock joint.The calculated values by the empirical formula exhibit an average relative errorδof≤9.01%compared to the test ones.

关 键 词：充填岩石节理 大型直剪试验 充填厚度 节理粗糙度系数 峰值剪切强度 

分 类 号：TU43[建筑科学—岩土工程]