下伏基岩堆积体边坡抗滑桩加固前后地震响应特征离心模型试验

发布时间：2018-02-01 02:45

本文关键词： 边坡工程下伏基岩堆积体边坡抗滑桩模型试验离心振动台地震响应　出处：《岩石力学与工程学报》2017年06期 　论文类型：期刊论文

【摘要】：为研究抗滑桩加固上覆堆积体——下伏基岩二元结构边坡的抗震机制,开展2组1∶50比尺的离心振动台模型试验,以对比分析下伏基岩堆积体边坡在抗滑排桩加固前后的地震响应特征与抗滑桩的桩身弯矩分布规律。试验时,输入4级加速度峰值连续增大的El Centro波,监测边坡模型坡面与坡体内的加速度响应、坡顶沉降变形以及抗滑桩上静、动弯矩的分布。试验结果显示由于抗滑桩抑制了上覆堆积体的下滑,坡顶的加速度峰值(PGA)放大系数、加速度反应谱以及竖向沉降变形均有不同程度的降低。抗滑桩一方面加固了上覆堆积滑体另一方面在坡体内产生了地震波的反射叠加效应,使得边坡水平响应加速度放大系数出现了桩前增大桩后减小的现象。下伏基岩堆积体边坡坡顶沉降与Arias烈度在抗滑排桩加固前后均具有良好的正相关线性关系。地震荷载作用过程中抗滑桩动力响应弯矩变化幅值明显大于地震作用后的静弯矩增量,且静弯矩与动弯矩变化幅值的分布均在基岩面附近达到峰值,易在基岩面附近造成抗滑桩的破坏,类似工况下抗滑桩的抗震配筋设计应充分考虑这一特点。
[Abstract]:In order to study the aseismic mechanism of anti-slide pile strengthening the slope of dualistic structure of overlying accumulation-lower voluminous rock, two groups of centrifugal shaking table tests with 1:50 scale were carried out. The characteristics of seismic response and the distribution of pile bending moment of anti-slide pile before and after reinforcement are analyzed by comparing the seismic response characteristics of the slope of voluminous rock accumulation body before and after the reinforcement of the anti-slide pile, and the distribution of bending moment of the anti-slide pile. An El Centro wave with the peak value of the 4th order acceleration is input to monitor the acceleration response of the slope model and the slope body, the settlement deformation of the slope top and the static state of the anti-slide pile. The distribution of dynamic bending moment. The test results show that the peak acceleration of the top of the slope is PGA-magnifying factor because the anti-slide pile suppresses the sliding of the overlying accumulation. The acceleration response spectrum and vertical settlement and deformation are reduced to some extent. Anti-slide piles reinforce the superimposed sliding body on the other hand it produces the reflection and superposition effect of seismic waves in the slope body. The acceleration magnification factor of the horizontal response of slope appears the phenomenon that the pile front increases and the pile decreases after the pile. The settlement of the slope top and Arias intensity of the lower voluminous accumulated body slope have good positive correlation before and after the reinforcement of the anti-slide row pile. The amplitude of moment variation of dynamic response of anti-slide pile is obviously larger than the increment of static moment after earthquake action. The distribution of the amplitude of static and dynamic bending moment reaches the peak near the bedrock surface, and it is easy to cause the damage of anti-slide pile near the bedrock surface. The seismic reinforcement design of anti-slide pile under similar conditions should be fully taken into account.
【作者单位】：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(41372314)~~
【分类号】：P315;TU473.1
【正文快照】： 1引言堆积体主要是由滑坡堆积、残坡堆积、崩坡堆积、冲洪堆积等第四系堆积作用形成的地质体,属于斜坡变形破坏后继续运动阶段的产物[1],在我国西南地区广泛分布。堆积体一般经历了斜坡的继续运动过程,具有比较特殊的空间结构,堆积体与基岩往往明确分离,基覆界面清晰,堆积体

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