基于3DEC的岩质高边坡三角体稳定性分析

Analysis of the Stability of Rock High Slope Triangles Based on 3DEC

两面临空的岩质边坡容易产生三角体稳定问题,受开挖卸荷作用的影响,路堑岩质高边坡的三角体稳定问题是突出的。连云港某路堑岩质高边坡开挖高度近200 m,在开挖过程中采取了喷锚支护措施,然而锚杆轴力的监测数据表明,对于规模较大的三角体,其稳定问题仍然突出,影响高速公路的安全运营。为此,在查清三角体边界条件的基础上,采用赤平极射投影法对代表性三角体稳定性进行定性分析,并采用3DEC数值模拟,分析该三角体的锚杆支护效果。结果表明,3DEC与赤平极射投影的分析结果具有较高的一致性,并被锚杆轴力监测数据所验证。

The rock slope with free faces on both sides will have to deal with the issue of triangle stability,which is prominent in rock high slope at cuttings for the effect of excavation load.In Lianyungang,a rock high slope at a cutting with excavation height of nearly 200 m was protected by taking measures of combined bolting and shotcrete in the excavation process.However,the monitoring data of anchor bolt axial force show that for the large-scale triangles,the stability problem is still outstanding and will affect the safe operation of expressway.Therefore,on the basis of identifying the conditions of the triangle boundary,the stability of the representative triangles was qualitatively analyzed with the equatorial horizon projection method,and the effect of anchor bolt support was analyzed by 3DEC numerical simulation.It turns out that the analysis results of 3DEC and the equatorial horizon projection are highly consistent and verified by the monitoring data of anchor bolt axial force.