摘要
水力耦合作用下结构面抗剪强度降低是诱发顺倾滑坡的主要原因之一,因此,研究浸水与应力共同作用下的结构面剪切力学行为可以帮助解译顺倾边坡的滑移失稳机制。以研山铁矿东帮顺倾含水边坡为工程背景,开展了不同浸水时长及应力水平共同作用后的贯通结构面剪切试验,在分析结构面剪切应力及应力—位移曲线变化规律的基础上,分别采用非线性回归及分阶段拟合方法构建了浸水与应力共同作用后的结构面剪切应力拟合公式及剪切本构模型。研究结果表明:①随着浸水时长和预应力增大,结构面峰值及残余剪切应力、黏聚力和内摩擦角呈现负指数型下降趋势,黏聚力劣化程度明显高于内摩擦角;②浸水时长及浸水过程中施加的预应力均会对结构面的剪切应力产生影响,且预应力大小的影响程度略高于浸水时长;③浸水、应力共同作用后,剪切法向应力的增加不仅提高了峰前阶段的剪切刚度,还降低了峰后阶段的刚度下降速率;④以屈服点、峰值点及残余应力点为分割点构建的新型剪切本构模型显著优于传统剪切本构模型,更加适用于描述浸水及应力共同作用后的结构面剪切行为。研究成果为理解和预测结构面控制型浸水边坡滑移失稳过程提供了坚实的试验基础,有助于提升对浸水边坡稳定性评估的科学性和准确性。
The reduction of shear strength of structural planes under the combined effect of water and stress is one of the main reasons for inducing dip-slope landslides.Therefore,studying the shear mechanical behavior of structural planes under the combined action of water and stress can help interpret the sliding instability mechanism of dip slopes.Taking the east slope of the Yanshan Iron Mine as the engineering background,shear tests of through structural planes under different water immersion durations and stress levels were carried out.Based on the analysis of the variation laws of shear stress and stress-displacement curves of structural planes,the shear stress fitting formula and shear constitutive model of structural planes under the combined action of water and stress were constructed by using nonlinear regression and piecewise fitting methods respectively.The research results show that:①With the increase of water immersion duration and pre-stress,the peak and residual shear stress,cohesion and internal friction angle of structural planes show a negative exponential decline trend,and the deterioration degree of cohesion is significantly higher than that of internal friction angle;②Both water immersion duration and pre-stress applied during water immersion have an impact on the shear stress of structural planes,and the influence degree of pre-stress is slightly higher than that of water immersion duration;③After the combined action of water and stress,the increase of shear normal stress not only improves the shear stiffness in the pre-peak stage,but also reduces the stiffness decline rate in the post-peak stage;④The new shear constitutive model constructed by taking the yield point,peak point and residual strength point as the dividing points is significantly superior to the traditional shear constitutive model and is more suitable for describing the shear behavior of structural surfaces after the combined action of water immersion and stress.The research results provide a solid ex-perimental basis for understanding and predicting the sliding instability process of water-immersed slopes controlled by structural planes,and are helpful to improve the scientificity and accuracy of the stability assessment of water-immersed slopes.
作者
张鹏海
贺忠媛
杨天鸿
刘溪鸽
侯俊
ZHANG Penghai;HE Zhongyuan;YANG Tianhong;LIU Xige;HOU Jun(School of Resource and Civil Engineering,Northeastern University,Shenyang 110819,China;Changchun Gold Research Institute Co.,Ltd.,Changchun 130012,China)
出处
《金属矿山》
北大核心
2025年第5期145-153,共9页
Metal Mine
基金
“十四五”国家重点研发计划项目(编号:2022YFC2903903)
国家自然科学基金项目(编号:52174070)。
关键词
水力作用
岩石结构面
剪切变形
本构关系
hydraulic action
rock structural planes
shear deformation
constitutive relation
