分级框架锚杆支护边坡的稳定性分析

Stability Analysis of Slope Supported by Graded Frame Anchor Rod

【目的】为探究云南勐绿高速公路某分级框架锚杆支护边坡的稳定性。【方法】采用FLAC3D建立三维数值模型,对边坡分别在未支护和支护工况下进行稳定性分析。选取支护边坡中部断面,对该断面中的锚杆(锚索)轴力进行监测,研究锚杆(锚索)轴力沿长分布的特性。【结果】结果表明:未支护边坡有极大可能沿潜在滑动面发生失稳破坏,分级框架锚杆支护结构能够有效抑制边坡整体位移,改善坡体内部塑性区分布,提高边坡的安全系数;锚杆锚固边坡内部根据锚杆发挥的不同作用分为主动区和被动区;锚索最大轴力处于自由段,锚固段内轴力分布并不均匀,呈递减趋势。【结论】研究表明框架锚杆组合结构对边坡具有良好的支护效果。

[Purposes]This paper aims to investigate the stability of slope supported by graded frame anchor rod at Menglv Expressway,Yunnan.[Methods]A three-dimensional numerical model was built using FLAC3D to analyse the stability of the slope under unsupported or supported conditions.The central section of the supported slope was selected and the axial force of the anchor rods(anchor cables)in this section was monitored to investigate the characteristics of the distribution of the axial force of the anchor rods(anchor cables)along the length.[Findings]The results show that the unsupported slope had a high possibility of sliding damage along the potential sliding surface;the graded frame anchor support structure could effectively suppress the overall displacement of the slope,improve the distribution of the plastic zone inside the slope and increase the safety factor of the slope;the internal part of the anchor rods anchored slope was divided into active and passive zones according to the different roles played by the anchor;the maximum axial force of the anchor cable was in the free section,and the distribution of the axial force in the anchored section was uneven and showed a decreasing trend.[Conclusions]This study shows that the combined frame anchor structure had excellent support effect on the slope.