地震力作用下边坡稳定性分析及加固效果评价

The earthquake force under the action of slope stability analysis and reinforcement effect evaluation

以天水市三阳川地区某黄土路基高边坡为研究对象,从当地多年以来发生地震状况考虑,采用GeoStudio软件进行数值模拟分析计算出其边坡的稳定性,并对失稳边坡采用锚杆加固,评价其加固效果。结果表明:(1)该边坡在静力状态下处于稳定状态,当输入峰值加速度为0.25 g的水平地震作用时,采用时程分析法、Newmark法两种评价方法显示边坡均已失稳,其中时程分析表明最小安全系数仅为0.83,Newmark法可知边坡产生的永久位移为2.02 cm;(2)将时程分析法和拟静力法得到的安全系数进行分析可知,采用平均安全系数过高的估计了安全系数,而将最小动力安全系数作为评价标准最为安全;(3)对失稳边坡采用锚杆加固,针对锚杆的入射角度不同进行数值模拟计算,计算结果显示,当锚杆入射角度为19°时加固效果最好,其加固后安全系数为1.25。另外,在地震力作用下锚杆加固时,采用三种方法评价得到,M-P法可能过高的评估了边坡的稳定性,Janbu法较为保守,采用Bishop法评价比较合理。

Taking a high slope of a loess roadbed in Sanyangchuan area of Tianshui city as a study,considering the earthquake conditions occurring in the area for many years,the stability of the slope is calculated by numerical simulation analysis using GeoStudio software,and the destabilized slope is reinforced with anchors to evaluate the reinforcement effect,the results show that:(1)the slope is in a stable state in static state,when the input peak acceleration of 0.25 g of the horizontal When the peak acceleration is 0.25 g,the slope is in a stable state under the static condition,and when the peak acceleration is 0.25 g,the slope is in a stable condition under the seismic action,the two evaluation methods of time-range analysis and Newmark method show that the slope is destabilized,in which the time-range analysis shows that the minimum safety coefficient is only 0.83,and the Newmark method shows that the slope produces a permanent displacement of 2.02 cm.(2)Comparing the safety coefficients obtained by the time-range analysis and the proposed static method,we can see that the use of the average safety coefficient is over-estimation.(3)The stabilized slope is reinforced by anchors,and numerical simulations are carried out for different angles of incidence of anchors,and the results show that the best reinforcement effect is achieved when the angle of incidence of anchors is 19°,and the coefficient of safety after reinforcement is 1.25.At the same time,the three methods are used in the evaluation of the reinforcement of anchors under the action of seismic force,which indicates that the M-P method may be overestimate the stability of the slope,and Janbu method is more conservative,while the evaluation using Bishop method is more reasonable.