权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development in numerical modeling and evaluation of hazard for slope deformation and failure

边坡变形破坏危害数值模拟与评价研究进展

基本信息

批准号：
20560462
负责人：
NISHIMURA Tsuyoshi
金额：
$ 2.25万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

Rockfall and slope failure pose serious hazards to roads and facilities in regional areas. The aim of this study is to build a procedure to evaluate the zone at risk using numerical simulation. This paper reports numerical procedures for (1) rockfall and (2) progressive failure in slope.(1) This study has adopted a spring-dashpot-slider system to model the bouncing phenomenon, occurring when boulders impact on the slope. The normal and tangential components (R_<en>, R_<et>) of restitution coefficient are expressed using the micro-properties (k_n, k_t η_n, η_t) of the system and the kinetic conditions.A small-scale free-fall-rebound test using a sphere boulder in laboratory was conducted. The results show that R_<et> increase with the ncrease of the incoming angle and the newly developed program can capture the increase of R_<et>. Parametric mulations have been performed at different spatial resolutions using sets of synthetic biplanar slopes haracterized by mean inclination and local asperities. The influence of controlling factors on the dispersion of rockfall rajectory has been evaluated by conducting 3D simulation. Finally, a rockfall encounter analysis is proposed using he numerical method developed in this study.(2) A numerical modeling of progressive failure in slope using the distinct element analysis has been developed. The numerical modeling consists of two stages. The first is to get the mechanical properties of synthetic specimens omposed of circular rigid elements with the bonded effect between elements. The second is to analyze deformation of a reduced-scale rock slope under the gravity increased condition. With the calibrated properties of the synthetic specimen being unchanged, evolution of displacements and the resulting initiation of failure surface in the slope odel are displayed. The modeling can give a possible failure volume of rock slope based on the geometrical data and strength properties, such as cohesion and internal friction angle.

落石及斜坡崩塌对区内道路及设施构成严重危险。本研究的目的是建立一个程序，以评估区域的风险，使用数值模拟。本文报道了（1）岩石崩落和（2）边坡渐进破坏的数值方法。(1)本研究采用弹簧-阻尼器-滑块系统来模拟巨石撞击斜坡时的弹跳现象。利用<en><et>系统的微观性质（k_n，k_t η_n，η_t）和动力学条件，给出了恢复系数的法向和切向分量（R_，R_）。计算结果表明，R_<et>（？）随入射角的增大而增大，新开发的程序可以捕捉到R_（？）的增大<et>。参数模拟已进行了不同的空间分辨率，使用合成双平面斜率harcharacterized平均倾角和局部粗糙集。通过三维数值模拟，分析了控制因素对落石运动轨迹离散性的影响。最后，提出了一个落石遭遇分析，使用在这项研究中发展的数值方法。(2)建立了边坡渐进破坏的离散元数值模拟方法。数值模拟包括两个阶段。第一种是考虑单元间的粘结效应，得到由圆形刚性单元组成的综合试件的力学性能。二是对一个缩比岩质边坡在重力增加条件下的变形进行了分析。在合成试件标定参数不变的情况下，展示了边坡模型中位移的演化过程和由此产生的破坏面的形成过程。该模型可以根据边坡的几何参数和强度特性（如粘聚力和内摩擦角）给出边坡可能的破坏体积。