卢应发, 张凌晨, 张玉芳, 李健, 刘珉玮, 朱蕾. 边坡渐进破坏多参量评价指标[J]. 工程力学, 2021, 38(3): 132-147. DOI: 10.6052/j.issn.1000-4750.2020.05.0286
引用本文: 卢应发, 张凌晨, 张玉芳, 李健, 刘珉玮, 朱蕾. 边坡渐进破坏多参量评价指标[J]. 工程力学, 2021, 38(3): 132-147. DOI: 10.6052/j.issn.1000-4750.2020.05.0286
LU Ying-fa, ZHANG Ling-chen, ZHANG Yu-fang, LI Jian, LIU Min-wei, ZHU Lei. MULTI PARAMETER EVALUATION INDEX OF PROGRESSIVE FAILURE OF LANDSLIDE[J]. Engineering Mechanics, 2021, 38(3): 132-147. DOI: 10.6052/j.issn.1000-4750.2020.05.0286
Citation: LU Ying-fa, ZHANG Ling-chen, ZHANG Yu-fang, LI Jian, LIU Min-wei, ZHU Lei. MULTI PARAMETER EVALUATION INDEX OF PROGRESSIVE FAILURE OF LANDSLIDE[J]. Engineering Mechanics, 2021, 38(3): 132-147. DOI: 10.6052/j.issn.1000-4750.2020.05.0286

边坡渐进破坏多参量评价指标

MULTI PARAMETER EVALUATION INDEX OF PROGRESSIVE FAILURE OF LANDSLIDE

  • 摘要: 传统的强度折减法就是以强度折减表征岩土体破坏后区的软化力学行为,该折减系数实质为描述边坡的整体稳定系数,但物理意义不明显。边坡稳定性是一个与众多因素相关的复杂科学课题,当边坡局部处于破坏后区应力状态时,其整体并不一定发生破坏,这种由破坏区和非破坏区组成的整体实质为非稳定力学系统,难以用连续介质力学的方法获得真实解。该研究提出了描述边坡点、面(滑面)和体(滑体)的多参量稳定性评价指标;定义了点破坏、面破坏(破坏面积比、破坏应力率、破坏应变率、摩擦力变化系数、正压力变化系数、下滑力变化系数、滑面位移变化系数等)和体破坏(富余摩阻力稳定系数、主推力稳定系数、富余摩阻力稳定系数、综合位移稳定系数、富余位移稳定系数等)边坡多参量稳定性评价指标,用来对边坡点破坏、滑面扩展、连通等实施全方位演化过程描述。并充分利用部分强度折减法、理想弹塑性模型、全过程本构模型等揭示滑坡点、面和体多参量随位移和力的变化规律;以传统和推广的不平衡推力条分法为例,利用多参量描述边坡的渐进破坏过程,揭示了在边坡临界状态一步一步移动过程中点、面及体的全过程多参量稳定性演化特征。大冶市桃花山边坡计算结果表明:多参量稳定性评价指标可以较好地描述桃花山边坡各特征量的演化规律,且基于理想弹塑性模型的部分强度折减条分法点、面描述参量(破坏率、破坏比等)的值小于全过程剪应力-应变本构模型的值,边坡整体稳定系数(主推力法、综合位移法和富余位移法)描述指标大于全过程剪应力-应变本构模型,但富余摩阻力法稳定系数则相反等。该研究重点是建立了边坡多参量稳定性评价指标,并使传统的稳定系数可以和该文建议的方法加以比较,为边坡监测预警提供了理论支撑。

     

    Abstract: The traditional strength reduction method (SRM) uses strength reduction to characterize the softening mechanical behavior of rock and soil after failure. The reduction coefficient is essentially a description of the overall stability coefficient of the slope, but its physical significance is not obvious. The stability of slope is a complex scientific subject related to many factors. When the local part of slope is in the state of failure stress, its whole failure may not happen, and the entire system composed of failure zone and non-failure zone is essentially in the state of an unstable mechanical state. It is difficult to obtain the real solution by the method of continuum mechanics. A multi- parameter evaluation index is put forward to describe the stability of the point, the surface (sliding surface) and body (sliding body) of slope. The definitions for point failure and surface failure (failure area ratio, failure stress rate, failure strain rate, etc.) are also presented. The different coefficients are developed, such as coefficient of frictional resistance, coefficient of normal force, coefficient of sliding force, coefficient of displacement along sliding surface, etc., for describing the law of force and displacement change. The safety factors of the entire slope are also clarified, such as surplus frictional resistance method, main thrust method, surplus frictional force method, comprehensive displacement method, surplus displacement method, and so on. It is possible to describe the all-round evolution process of slope by using the multi- parameter evaluation index. Under the condition of making full use of the partial strength reduction method (PSRM), or the perfect elasto-plastic model (PEPM), and the complete process constitutive model (CPCM), the multi parameters of point, surface and body of slope can be obtained with the change of displacement and force. Taking the traditional and extended unbalanced thrust method as an example, the progressive failure process of slope can be described by using the multi- parameters and can reveal the characteristics of the critical stress state movement step by step. The calculation results of Taohuashan slope in Huangshi City of Hubei Province show that: the multi parameter evaluation index can describe the evolution law of progressive failure of the slope, the values of the point and surface multi- parameters obtained by PSRM with the PEPM are smaller than that obtained with the CPCM; and the overall safety factors of the main thrust method, comprehensive displacement method and surplus displacement method using the PEPM are larger than that of the CPCM, but the stability coefficient of surplus frictional force method is opposite, etc. The focus of this study is to establish the slope multi-parameter stability evaluation index, and to make the traditional stability coefficient can be compared with the method proposed in this paper, which provides a theoretical support for slope monitoring and early warning.

     

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