预应力锚固岩体地震响应规律的离心振动试验分析

Centrifugal Vibration Test Analysis of Seismic Response Laws of Prestressed Rock Mass

摘要:

为了探明锚固边坡随地震加速度变化的响应规律和锚索本身在地震作用下的具体响应过程,借助中国水利水电科学研究院配置的离心振动台试验设备,通过开展离心机模型试验,研究了简谐地震波作用下锚固边坡的位移变化过程,以及不同位置锚索、同一锚索不同点位的应变响应过程与规律。研究结果表明:边坡竖向位移与锚索应变值震荡频率和输入地震加速度频率同步性较好;锚索的应变和受力呈现出自上而下递减的状态,滑面附近的锚索需要发挥更大的加固作用。随着地震烈度的增大,锚索发挥更大的加固作用,也体现出了锚索的被动支护作用。该试验得到了锚固边坡在地震作用下的坡体位移并分析了锚索响应规律,也验证了离心模型试验对此类问题研究的较强适用性。

Abstract:

In order to clarify the response patterns of the anchored slope under the variation of seismic acceleration and the specific response process of the anchor cable under the action of earthquakes, by using the centrifugal vibration test equipment configured by the China Water Resources and Hydropower Research Institute, centrifugal model tests were carried out to study the displacement change process of the anchored slope under the action of harmonic seismic waves, as well as the strain response process and patterns of different positions of the anchor cable and different points of the same anchor cable under the action of earthquakes. The research results show that the oscillation frequency of the vertical displacement of the slope and the strain value of the anchor cable is in good synchronization with the input seismic acceleration frequency; the strain and force of the anchor cable show a decreasing state from top to bottom, and the anchor cables near the sliding surface need to play a greater reinforcing role. With the increase of seismic intensity, the anchor cable plays a greater reinforcing role, and also demonstrates the passive support function of the anchor cable. This test obtained the analysis of the displacement and response patterns of the slope and anchor cables under the action of earthquakes for the anchored slope, and also verified the strong applicability of the centrifugal model test for the research of such problems.