岩质反倾边坡局部锚杆加固分析方法研究

Analytical approach of counter tilt rock slopes locally reinforced by fully grouted bolts

全长黏结型锚杆作为一种有效且经济的加固手段,在边坡工程中得到广泛的应用。基于最新提出的岩质反倾边坡弯曲倾倒破坏分析方法和极限平衡理论,建立锚杆局部加固后该类边坡的力学模型和稳定性分析方法,给出加固后的边坡安全系数计算公式,并将理论分析结果与离散元(UDEC)计算结果进行对比分析。研究结果表明:理论解与UDEC计算的数值解具有较高的一致性,两者相互得到了验证;用全长黏结型锚杆加固岩质反倾边坡时,最优加固位置位于叠合倾倒区内,具体位置与边坡的物理力学参数、锚杆锚固参数有关;减小锚杆与层面的夹角,能够充分发挥锚杆对层面的阻滑作用,进而提高加固效果。

The reinforcement of fully grouted bolts is widely used in slope engineering due to its proven efficacy and low cost. Based on the newly proposed approach of stability analysis of counter tilt rock slopes upon flexural-toppling failure,a mechanical model of such slopes reinforced by fully grouted bolts was established. The formula of slope safety factor after reinforcement was given. In addition,the comparison between the theoretical method and discrete element method（UDEC） was made. The simulated results are consistent with those obtained with the analytical method. The optimal reinforcement position is located in the superimposed toppling zone and the precise location is related to the parameters of slope and anchoring. Reducing the angle between the bolt and discontinuity can make the full use of the shear resistance of bolt.