锚固岩石边坡地震稳定性拟动力分析

Seismic stability of anchored rock slope using pseudo-dynamic method

地震易发地区的锚固岩石边坡,需要研究其地震稳定性。对于锚固典型岩石边坡,在考虑水平与竖向地震力、张裂缝积水深度、坡顶超载、锚索倾角、锚索位置、锚索拉力及静水与动水压力等的条件下,运用拟静力和拟动力方法分别推导了不同工况条件下其抗滑和抗倾覆地震安全系数。分析表明,竖向向上地震力有利于锚固岩石边坡的抗滑稳定,而竖向下的地震力有利于锚固岩石边坡的抗倾覆稳定;在相同工况条件下,当岩体放大系数等于1.0时,拟动力与拟静力方法所得锚固岩石边坡地震安全系数相差无几,但是,当岩体放大系数逐渐增大时,拟动力方法所得地震安全系数越来越明显地小于拟静力方法所得地震安全系数。因此,在抗震设计当中适当的考虑岩体放大系数,将会有利于锚固岩石边坡的安全设计。

In seismic prone areas,it is necessary to study seismic stability of anchored rock slope.For anchored typical rock slope,the seismic safety factor of anchored rock slope against sliding and overturning failures is deduced by pseudo-static method and pseudo-dynamic method,respectively,in the different working conditions,considering both horizontal and vertical seismic forces,depth of water in tension crack,surcharge,dip angle of rock bolt,rock bolt position,tension force of rock bolt,and both hydrostatic and hydrodynamic pressures.The conclusions can be drawn that the upward vertical seismic force is conducive to the stability of anchored rock slope against sliding failure;but the downward vertical seismic force is conducive to the stability of anchored rock slope against overturning failure;in the same working conditions,the pseudo-dynamic and pseudo-static safety factors are all the same as the amplification factor is equal to 1.0;but the pseudo-dynamic safety factor is more and more obvious less than the pseudo-static safety factor as the amplification factor gradually increases.In seismic design,it will be beneficial to the safety design of anchored rock slope by appropriately considering the amplification factor.