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工程科学与技术:2021,53(3):43-52
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基于振动台试验的含软弱夹层堆积体边坡动力响应规律与失稳破坏现象研究
(1.西南交通大学 土木工程学院,四川 成都 610031;2.中铁二院工程集团有限责任公司 地勘院 四川 成都 610031)
Research on Dynamic Response and Instability Failure Phenomenon of Deposit Slope with Weak Interlayer Based on Shaking Table Test
(1.School of Civil Eng., Southwest Jiaotong Univ., Chengdu 610031, China;2.Geological Prospecting Inst., Railway Second Academy Eng. Group Co., Ltd., Chengdu 610031, China)
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投稿时间:2020-11-02    修订日期:2021-05-08
中文摘要: 针对川藏铁路沿线典型潜在滑坡灾害点,设计完成了几何相似比为1∶10的含软弱夹层堆积体高陡边坡振动台试验,从堆积体边坡失稳破坏现象与动力响应规律等方面开展了系统研究,得出以下结论:边坡滑塌是一个均衡渐进的过程,地震初期,在重力和地震力耦合作用下,滑体表面出现土体剥落;随着地震动持续,滑体顶部开裂,滑体表面裂缝增多并向前缘锁固段发展;最终,锁固段发生渐进性破坏,滑动面贯通,滑体从前缘剪出口滑出形成滑坡;以坡脚处的加速度峰值为基准,在不同烈度汶川卧龙地震波作用下,堆积体高陡边坡临空面方向、竖直方向上PGA沿着高程均有不同程度的放大,且边坡临空面方向上加速度放大性大于竖直方向上的。不论是边坡临空面方向还是竖直方向,随着输入地震动峰值的增大,加速度放大系数沿高程逐渐增大,在PGA为0.4g时达到峰值;滑床与滑体间运动的不一致性是诱发滑坡的一项主控影响因素,在堆积体滑塌前,堆积体内临空面的加速度峰值及其傅里叶幅值大于滑床,且两者的卓越频带基本一致;当堆积体开始滑塌时,堆积体内临空面的加速度峰值及其傅里叶幅值小于滑床,且卓越频带逐渐向低频转移,而滑床内的加速度傅里叶谱的主频和幅值基本不变。
Abstract:Aiming at the typical potential landslide disaster points along the Sichuan-Tibet Railway, a shaking table test of a high-steep deposit slope with weak interlayer was design and completed with a geometric similarity ratio of 1∶10. Systematic research has been carried out from the aspects of instability failure phenomenon and dynamic response of deposit slope. The conclusions are as follows: The landslide is a balanced and gradual process. At the beginning of the earthquake, under the influence of gravity and seismic force, the soil on the surface of slope began to peel off; as the ground motion continued, the top of the sliding body cracked, and the cracks on the surface of the sliding body increased and developed at the front edge locking section; finally, the locking section was damaged, the sliding surface was penetrated, and the sliding body slid out from the cutting outlet of the leading edge to form a landslide. Based on the PGA of the foot of slope, under the action of Wenchuan-Wolong seismic waves of different intensities, the PGA along the elevation of high-steep deposit slope had different degrees of magnification in the direction of the free surface and the vertical direction, the acceleration amplification effect on the free surface direction of slope was bigger than that on the vertical direction. Regardless of whether it was in the surface direction or the vertical direction of the slope, with the increase of the input ground motion peak value, the acceleration amplification factor gradually increased with elevation, and reached the peak value when the PGA was 0.4g. The inconsistency of the movement between the sliding bed and the sliding body was one of the main controlling factors that induced landslides. Before the accumulation body collapses, the acceleration peak value and the Fourier amplitude of the surface of the deposit slope were greater than that of the sliding bed, and the excellent frequency bands of the two were basically the same. When the accumulation body begins to collapse, the acceleration peak value and the Fourier amplitude of the accumulation body surface were smaller than that of the sliding bed, and the superior frequency band gradually shifted to low frequency, while the main frequency and amplitude of the Fourier spectrum of acceleration in the sliding bed were basically unchanged.
文章编号:202000935     中图分类号:    文献标志码:
基金项目:中铁二院工程集团有限责任公司科研项目(KYY2019145(19-20));四川省科技计划项目(2020YJ0253);四川省教育厅科研项目(16ZB0012);国家自然科学基金项目(5207082465)
作者简介:第一作者:杨长卫(1987-),男,副研究员,博士.研究方向:高速铁路防灾减灾与岩土工程抗震等.E-mail:1209732335@qq.com;通信作者:王栋,E-mail:278946257@qq.com
引用文本:
杨长卫,郭雪岩,刘阳,王栋.基于振动台试验的含软弱夹层堆积体边坡动力响应规律与失稳破坏现象研究[J].工程科学与技术,2021,53(3):43-52.
YANG Changwei,GUO Xueyan,LIU Yang,WANG Dong.Research on Dynamic Response and Instability Failure Phenomenon of Deposit Slope with Weak Interlayer Based on Shaking Table Test[J].Advanced Engineering Sciences,2021,53(3):43-52.