水平厚层状岩质边坡地震动力破坏过程颗粒流模拟

发布时间：2018-03-21 01:45

本文选题：边坡工程　切入点：水平厚层状岩质边坡　出处：《岩石力学与工程学报》2017年09期 　论文类型：期刊论文

【摘要】：基于二维颗粒流软件(PFC2D)的人工合成岩体技术,研究岩桥长度和节理间距不同组合形式下的含水平断续节理厚层状岩质边坡在地震作用下的破坏模式、动力响应规律以及岩桥段应力演化特征。研究结果显示:地震动作用下,含水平断续节理厚层状岩质边坡主要发生溃散型破坏、拉裂滑移块体倾倒混合破坏和拉裂水平滑移混合破坏;水平断续节理是控制边坡动力稳定性的关键因素。节理间距对边坡破坏模式起控制性作用:当节理间距较小时,易发生溃散型破坏;当节理间距较大时,易发生拉裂滑移块体倾倒破坏和拉裂水平滑移混合破坏。岩桥长度和节理间距共同控制着边坡岩体破碎程度,从而控制着边坡失稳破坏时滑动面的个数,当节理间距很小或者节理间距较大、岩桥长度较小时,发生单滑动面破坏;当节理间距和岩桥长度均较大时,发生双滑动面破坏。在地震动力作用下,岩桥段首先发生破坏,随后各节理间也产生破坏并贯通。岩桥长度和节理间距对边坡动力响应均产生一定影响,随着节理间距减小、岩桥长度增大,峰值位移、峰值速度增大,对加速度PGA放大系数的影响区域集中在边坡坡表、坡脚等部位。地震作用下,含水平断续节理厚层状岩质边坡岩桥段应力演化、裂纹萌生与输入的地震波加速度具有良好的一致性。
[Abstract]:Based on the technology of synthetic rock mass based on two-dimensional particle flow software (PFC2D), the failure mode of thick layered rock slope with horizontal intermittent joints in different combination forms of bridge length and joint spacing under seismic action is studied. The dynamic response law and stress evolution characteristics of rock bridge section are studied. The results show that collapse failure occurs mainly in thick layered rock slope with horizontal intermittent joints under the action of ground motion. The collapse mixed failure and horizontal slip failure of the tension crack and slip block; Horizontal discontinuous joint is the key factor to control the dynamic stability of slope. The joint spacing plays a controlling role in slope failure mode: when the joint spacing is small, it is prone to collapse failure, and when the joint spacing is large, The rock bridge length and joint spacing control the degree of rock mass breakage together, thus controlling the number of sliding surfaces when the slope is unstable. When the joint spacing is small or the joint spacing is large, the single sliding plane failure occurs when the rock bridge length is small, and when the joint spacing and the rock bridge length are both large, the double sliding plane failure occurs. The rock bridge length and the joint spacing have a certain influence on the slope dynamic response. With the decrease of the joint spacing, the rock bridge length increases, the peak displacement and the peak velocity increase. The influence area of acceleration PGA magnification factor is concentrated in the side slope table, slope foot and so on. Under the earthquake, the stress evolution of thick layered rock slope with horizontal intermittent joints is obtained. The crack initiation is in good agreement with the input seismic acceleration.
【作者单位】：中国地质大学(武汉)工程学院;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金资助项目(51209198)~~
【分类号】：TU45

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