| 岩层倾角对顺倾向边坡地震效应的影响 |
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| 引用本文： | 丁梓涵,赵其华,彭社琴,陈继彬,喻豪俊.岩层倾角对顺倾向边坡地震效应的影响[J].西北地震学报,2015,37(4):956-962. |
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| 作者姓名： | 丁梓涵 赵其华 彭社琴 陈继彬 喻豪俊 |
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| 作者单位： | 地质灾害防治与地质环境保护国家重点实验室, 四川成都 610059;地质灾害防治与地质环境保护国家重点实验室, 四川成都 610059;成都理工大学环境与土木工程学院, 四川成都 610059;成都理工大学环境与土木工程学院, 四川成都 610059;成都理工大学环境与土木工程学院, 四川成都 610059 |
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| 基金项目： | 国家重点基础研究发展计划(2011CB013501);长江学者和创新团队发展计划(IRT0812) |
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| 摘 要： | 利用FLAC3D软件模拟地震作用下不同岩层倾角的顺倾向边坡,对比坡面峰值加速度放大系数、峰值位移、地震作用结束后坡体剪应变增量的变化规律,探讨岩层倾角对顺倾边坡地震效应的影响。研究表明:(1)在水平地震波作用下,坡面水平峰值加速度放大作用随岩层倾角增大而线性减小;(2)当岩层倾角小于软弱岩层内摩擦角时,坡面峰值位移较小且变化规律受岩层倾角影响不明显,当岩层倾角大于软弱岩层内摩擦角且小于30°时坡面峰值位移增大,大于60°时减小;(3)岩层倾角小于坡角时,残余剪应变增量最大值集中在坡面中下部软弱岩层处,反之,剪应变增量最大值出现在整个坡面并呈弧形区。
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| 关 键 词： | 岩层倾角 数值模拟 顺倾向层状岩质边坡 地震效应 |
| 收稿时间： | 2014/8/20 0:00:00 |
Impact of Dip Angle of Rock Stratum on Seismic Response of Consequent Slope |
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| DING Zi-han,ZHAO Qi-hu,PENG She-qin,CHEN Ji-bin and YU Hao-jun.Impact of Dip Angle of Rock Stratum on Seismic Response of Consequent Slope[J].Northwestern Seismological Journal,2015,37(4):956-962. |
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| Authors: | DING Zi-han ZHAO Qi-hu PENG She-qin CHEN Ji-bin and YU Hao-jun |
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| Institution: | State Key Laboratory of Geo-hazard Prevention and Geo-environment Protection, Chengdu 610059, Sichuan, China;State Key Laboratory of Geo-hazard Prevention and Geo-environment Protection, Chengdu 610059, Sichuan, China;College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, Sichuan, China;College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, Sichuan, China;College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, Sichuan, China |
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| Abstract: | The southwest of China is located in a seismically active area, and in recent years earthquakes exceeding 7.0 magnitude have occurred in many locations in Yunnan and Sichuan provinces. In addition, the consequent stratified rock slope is developed well in the southwest of China, and this means that the strike and inclination direction of the slope is same as that of the rock stratum. Instability and failure of the consequent stratified rock slope is common during the construction of railways, highways, and water conservancy and hydropower engineering projects in the southwest of China. This is an urgent engineering construction problem which must be recognized and solved as soon as possible. Currently, there are certain researches being conducted on the seismic effects of this kind of slope, and the methods being used focus on the analysis of mechanical systems and model experiments. In these studies, the range of the rock stratum''s dip angle is not sufficiently comprehensive and do not fully represent the seismic effects of dip angle of the rock stratum on the slope. Nor is the thickness of the rock layer in numerical simulations sufficiently precise, which affects the accuracy of the numerical simulation results. Using FLAC3D software, in this study we simulated the consequent stratified rock slope for different dip angles of rock stratum(0°~90°) and detailed the thickness of the stratum(sandstone is 1 m thick, weak mudstone is 0.1 m thick) under seismic action. We then contrasted the regulation of the peak acceleration amplification factor, peak displacement, and shear strain increment after seismic action, and explored the impact of the rock stratum''s dip angle on the seismic effect of the consequent stratified rock slope. This analysis will help to explain the instability mechanisms and slope failure modes, and lay the groundwork for disaster prevention in consequent stratified rock slopes. The study results are as follows:First, the peak horizontal acceleration amplification factor, which is relative to the slope toe, increases with increase in slope height, with the maximum occurring at the slope shoulder. This rule conforms to existing experimental conclusions. Then, under the effect of horizontal seismic action, slope horizontal peak acceleration amplification, which is relative to the initial seismic waves, decreases linearly with increase in the dip angle of the rock stratum. Second, when the dip angle of the rock stratum is less than the internal friction angle of weak rock stratum, the slope peak displacement is small and the influence of the dip angle is not obvious. When the dip angle of the rock stratum is larger than internal frictional angle of weak rock stratum, the slope peak displacement will increase at first and then decrease with increases in the dip angle. This displacement increases when the dip angle of the rock stratum is less than 30°, and decreases when the dip angle of the rock stratum is larger than 60°. Third, when the dip angle of the rock stratum is less than the slope angle, the maximum value of the slope residual shear strain increment after seismic action is concentrated in the soft rock in the middle and lower segments of the slope. When the dip angle of the rock stratum is larger than the slope angle, the maximum value of the residual shear strain increment after seismic action will be in the whole slope, thus forming an arc zone. |
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| Keywords: | dip angle of rock stratum numerical simulation consequent stratified rock slope seismic effect |
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