摘要
工程岩体边坡中伴生着大量随机裂隙,开挖卸荷很容易导致裂隙扩展,最终导致边坡失稳.但卸荷边坡稳定性涉及断裂力学、岩体力学、地质工程、水力学等多个学科,很难精确分析.针对裂隙岩体边坡,借助离散元方法定义裂隙密度,分析应力水平、台阶高度、裂隙密度等不同因素对边坡卸荷程度的影响.研究结果表明:开挖过程中,当应力水平由0.5 MPa增至2 MPa时,开挖面处最小主应力由0.01 MPa增加到0.2 MPa,最大位移由1.4 cm增加到6.5 cm;随着台阶高度减小,卸荷产生的拉应力区范围减小,变形主要位于中下部岩体;当裂隙密度增大时,边坡最大位移由1.4 cm增至5.5 cm,裂隙沿着优势面贯通趋势越明显.研究成果可为裂隙岩体边坡开挖卸荷变形控制提供参考.
There are a large number of random cracks in the engineering rock slope.Excavation unloading can easily lead to the expansion of cracks and ultimately lead to the instability of the slope.However,the stability of unloading slope involves many disciplines such as fracture mechanics,rock mechanics,geological engineering and hydraulics,and it is difficult to analyze accurately.In this paper,the fracture density of fractured rock slope is defined by discrete element method,and the influence of different factors such as stress level,step height and fracture density on the unloading degree of slope is analyzed.The results show that when the stress level increases from 0.5 MPa to 2 MPa,the minimum principal stress increases from 0.01 MPa to 0.2 MPa,and the maximum displacement increases from 1.4 cm to 6.5 cm.With the decrease of bench height,the range of tensile stress area caused by unloading decreases,and the deformation is mainly located in the middle and lower rock mass.When the crack density increases,the maximum displacement of the slope increases from 1.4 cm to 5.5 cm,and the trend of the crack penetrating along the dominant surface is more obvious.The research results can provide reference for the control of excavation unloading deformation of fractured rock slope.
作者
罗沙
朱珍德
石崇
LUO Sha;ZHU Zhende;SHI Chong(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China;Research Institute of Geotechnical Engineering,Hohai University,Nanjing 210024,China)
出处
《河南科学》
2022年第12期1919-1926,共8页
Henan Science
基金
国家自然科学基金重点项目(41831278)
国家自然科学基金面上项目(51679071)。
关键词
岩质边坡
开挖卸荷
裂隙扩展
颗粒离散元
rock slope
excavation unloading
crack propagation
granular discrete element
