多级框架锚索和抗滑桩联合作用下边坡抗震性能的振动台试验研究

发布时间：2018-03-12 19:13

  本文选题：锚索　切入点：预应力损失　出处：《岩土力学》2017年02期 　论文类型：期刊论文

【摘要】：基于原型边坡设计了大型振动台模型试验,通过监测锚索轴力、桩身土压力、坡体加速度和坡面位移时程,研究多级锚索框架梁与双排抗滑桩组合结构加固含软弱夹层岩质边坡的地震动力特性。试验结果表明:在0.15g El Centro地震波激振时锚索预应力产生损失,最大损失比为23%,建议对变形等级要求较高的边坡在锚索抗震设计时适当提高预应力初始值1.2~1.3倍;沿边坡不同高度布置的锚索其轴力响应峰值几乎同一时刻到达,而峰值增加比例呈现出空间非一致性,在锚索抗震设计时应以坡体中部抗滑桩为界将边坡分为上、下区分别考虑;坡脚抗滑桩受荷段、锚固段土压力均随着输入地震波峰值加速度的增加而增大,主动土压力分布规律将由"上小下大"转变成"上大下小"的形状,被动土压力Ⅰ、Ⅱ区的分界点将向桩体下部发展;锚索与抗滑桩在地震时表现为协同工作机制,工程设计中要充分考虑地震效应对桩锚下滑力分担比的影响。该研究成果可为更加合理地考虑地震区锚索框架梁与抗滑桩组合支护结构的设计提供指导。
[Abstract]:A large-scale shaking table model test was designed based on the prototype slope. Through monitoring the axial force of the anchor cable, the earth pressure of the pile, the acceleration of the slope body and the time history of the displacement of the slope, The seismic dynamic characteristics of multi-stage anchor cable frame beam combined with double-row anti-slide pile for strengthening rock slope with weak intercalation are studied. The experimental results show that the prestressing force of anchor cable is lost when the seismic wave is excited by 0.15 g El Centro. The maximum loss ratio is 23. It is suggested that the pre-stressed initial value should be increased by 1.2 to 1.3 times in the seismic design of Anchorage cable, and the peak value of axial force response of the anchor cable with different height of the slope should be reached almost at the same time. The proportion of peak value increase shows spatial inconsistency. In seismic design of Anchorage cable, the slope should be divided into upper and lower sections by taking the anti-slide pile in the middle of the slope as the boundary, and the bearing section of the anti-slide pile at the foot of the slope should be considered separately. The earth pressure in Anchorage section increases with the increase of the peak acceleration of the input seismic wave. The distribution of active earth pressure will change from "upper small to lower big" to "upper big and lower small". The boundary point of area 鈪，

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