地震动强度增大过程中边坡土体的损伤演化及其计算方法研究  

Study on Damage Evolution and Calculation Method of Slope Soil During the Increase of Ground Motion Intensity

作　　者：贾文君[1] JIA Wenjun(Gansu Vocational and Technical College of Communications,Lanzhou 730070,China)

机构地区：[1]甘肃交通职业技术学院,兰州730207

出　　处：《华南地震》2022年第3期116-122,共7页South China Journal of Seismology

基　　金：甘肃省教育厅2019年度高等学校创新能力提升项目(2019A-229)。

摘　　要：地震作用下边坡失稳破坏过程也是土体损伤变形演化过程,当前边坡模型试验中土体损伤的定量计算方法尚未提出;研究以兰州新区职教园区内一填方边坡为原型,开展了地震动强度逐级增大条件下边坡失稳破坏的模型试验,研究边坡变形失稳过程中相关物理量随地震动强度的变化规律,进而提出土体损伤的计算公式。研究结果发现:在地震动强度增大过程中,坡肩土体损伤变形最为显著,传递函数频谱随地震动强度增大呈现有规律的减小变化,土体阻尼比随地震强度增大呈现指数函数增大变化,据此提出了基于归一化阻尼比的土体损伤量计算公式,该公式计算的土体损伤量也呈现指数函数增大变化,反映了地震动作用下土体的非线性损伤变形破坏过程。文中提出的土体损伤量计算方法可为基于模型试验的边坡稳定性评价提供理论依据。The process of slope instability and failure under earthquake is also the evolution process of slope soil damage and deformation. At present,the quantitative calculation method of soil damage in slope model test has not been proposed. Taking a filling slope on the west side of a college campus in Higher Vocational Education Zone of Lanzhou New Area as the prototype,the model tests of slope instability under the gradually increasing the ground motion intensity is carried out. In the process of slope deformation and instability,the variation law of transfer function spectrum with ground motion intensity is analyzed and studied,and then the calculation method of soil damage is put forward. The results show that the damage and deformation of the soil at the slope shoulder is the most significant in the process of increasing the ground motion intensity,the frequency spectrum of the transfer function decrease regularly with the increase of the ground motion intensity, and the damping ratio of the soil in this area changes exponentially with the increase of ground motion intensity. Therefore,a formula for calculating the amount of soil damage based on the normalized damping ratio is proposed,and the amount of soil damage calculated by the formula also shows the law of exponential function increase,reflecting the nonlinear damage,deformation and failure process of soil mass under the ground motion. The calculation method of soil damage proposed in this paper could provide a theoretical basis for slope stability evaluation based on model test.

关 键 词：黄土边坡 模型试验 地震动 土体损伤 

分 类 号：P642.22[天文地球—工程地质学]