| 地震动参数对斜坡加速度动力响应规律的影响 |
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| 引用本文： | 刘汉香,许强,范宣梅.地震动参数对斜坡加速度动力响应规律的影响[J].地震工程与工程振动,2012,32(2):41-47. |
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| 作者姓名： | 刘汉香 许强 范宣梅 |
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| 作者单位： | 1. 成都理工大学地质灾害防治与地质环境保护国家重点实验室(成都理工大学),四川成都,610059
2. International Institute for Geo-information Science and Earth Observation(ITC), University of Twente, Enschede, The Netherlands |
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| 基金项目： | 国家重点基础研究发展计划课题项目，教育部创新团队发展计划项目，地质灾害防治与地质环境保护国家重点实验室自主研究课题项目 |
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| 摘 要： | 2008年‘5.12’汶川大地震诱发斜坡地质灾害在空间分布上表现出了明显的高程效应和岩性效应。本文采用上硬下软和上软下硬两种典型岩性组合斜坡模型,完成了1:100比尺的振动台试验。文中重点分析了地震波类型(频谱)、激振方向和地震动三参数对斜坡模型水平向加速度动力响应规律的影响。分析结果表明:(1)水平单向激振时,15Hz正弦波和汶川地震波作用下的高程放大效应主要体现在斜坡模型中上段,两者在上软下硬组合斜坡模型中产生了近乎相同的水平向加速度动力响应规律,原因主要在于两者的卓越频率接近。(2)模型对合成向汶川地震波的放大作用依次超过单向水平向和竖直向汶川波的作用,且合成向与水平单向汶川地震波的作用规律基本相同。(3)随着振动强度增加,模型对低频波的放大作用增强。(4)在合成向汶川地震动作用下,随着振动强度增加,模型各高程处的水平向加速度峰值(PGA)逐渐增加,其相应的放大系数在模型中上段逐渐降低至2.0以下,最终趋于平缓,表明模型沿高程向的放大效应逐渐减弱。此外,各参数对模型的水平向加速度响应因模型自身的岩性组合结构而异,随着振动强度增加,上硬下软斜坡模型中上部的水平向速度响应值基本保持在1.0～2.7倍于上软下硬斜坡模型中上部的水平向加速度响应值这一水平。
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| 关 键 词： | 斜坡 振动台试验 地震波方向 激振方向 地震动强度 加速度动力响应规律 |
Effects of seismic parameters on acceleration responses of slopes |
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| LIU Hanxiang
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XU Qiang
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FAN Xuanmei.Effects of seismic parameters on acceleration responses of slopes[J].Earthquake Engineering and Engineering Vibration,2012,32(2):41-47. |
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| Authors: | LIU Hanxiang XU Qiang FAN Xuanmei |
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| Institution: | 1.State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection,Chengdu University of Technology,Chengdu 610059,China; 2.International Institute for Geo-information Science and Earth Observation(ITC),University of Twente,Enschede,The Netherlands) |
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| Abstract: | Evident topographic effect and lithological effect were observed in spatial distribution of secondary geo-hazards caused by ’May 12’ Wenchuan earthquake in 2008.Two model slopes composed of different lithology combinations with high strength materials overlying low strength materials and low strength materials overlying high strength materials,are designed to conduct a shaking table test with the geometric scale of 1:100.The effect of seismic parameters on horizontal acceleration responses of two model slopes has been analyzed in detail.Results show that:(1) when in horizontal input motion only,the topographic amplification effects under sine waves of 15 Hz vibration frequency and real waves only occur in the middle to the top part of models.Moreover,the response rules resemble each other in the model with low strength materials overlying high strength materials due to the similar dominant frequencies.(2) Under real waves,the effects under complex direction excitation are basically stronger than those in horizontal motion only and vertical motion only in sequence,and response rules under the first two conditions are similar in curve shape.(3) as input intensity increases,the amplification effects are strengthened in the lower frequencies.(4) under the complex direction excitation of real waves,the peak horizontal accelerations at each elevation demonstrate increase tendency,while their corresponding amplification factors decrease gradually in the upper part of models until the values keep stable bellow 2.0,indicating the decay of the topographic effect.In addition,effects of seismic parameters on horizontal acceleration responses of model slopes vary with the lithology combination,and as input intensity increases,the effects on the model with high strength materials overlying low strength materials are 1.0～2.7 times stronger than those on the model with low strength materials overlying high strength materials in the middle to the top part. |
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| Keywords: | slopes shaking table test wave kinds excitation directions input intensity dynamic acceleration response |
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