地震荷载下预应力锚固边坡离心振动模型试验研究

Centrifugal vibration model test of prestressed anchored slope subjected to earthquake load

预应力锚索作为边坡支护的重要技术,已经在边坡加固中得到了广泛应用,但锚固岩质边坡在地震荷载作用下的响应机制以及锚索受力变形规律还不明确。为此,开展了预应力锚固边坡离心振动模型试验,系统介绍了模型相似设计、模型设计与制作、地震荷载施加等试验关键技术,并以紫坪铺水库泄洪洞进口岩质边坡为原型,开展了简谐地震波作用下的锚固边坡离心模型试验。对试验结果进行了分析,并对该离心振动试验的主要影响因素进行了探讨。研究结果表明:地震作用下预应力锚索发挥了较强的被动支护作用,且越靠近滑面处应力应变响应越明显;边坡竖向位移与应力应变值的响应情况随地震烈度的改变产生明显变化。研究成果可为今后离心振动模型试验的开展提供参考与借鉴。

As an important support method,prestressed anchor cable is widely used in slope reinforcement.However,the response mechanism of the anchored rock slope as well as the stress and deformation law of the anchor cable under seismic load are still unclear.In this paper,the key technologies of the centrifugal vibration model test were introduced,which included model similarity design,model manufacture,and application of seismic load.Based on the rocky inlet slope at the spillway tunnel of Zipingpu Reservoir,a centrifugal model test of the anchored rock slope under action of the simple harmonic seismic wave was performed.The test results were analyzed,and the main influencing factors of this trial were discussed.The results show that the prestressed anchor cable plays a strong role in passive support.The closer the prestressed anchor cable is to the sliding surface,the more obviously the stress and strain response appears.There is also a significant change in the vertical displacement of the slope and the stress and strain response of the anchor cable as the seismic intensity changes.This study may provide an important reference for centrifugal vibration tests in the future.