膨胀土边坡入渗稳定性分析与锚杆支护参数研究

Research on Stability and Anchor Support Parameters of Expansive Soil Slope Under the Condition of Seepage

裂隙的存在是膨胀土边坡在降雨条件下极易失稳的重要因素。为探索膨胀土边坡在降雨条件下渗流场变化特点与稳定性,进行了0,2m与4m裂隙深度下的边坡饱和-非饱和渗流有限元数值模拟,在渗流分析基础上进行基于极限平衡法的膨胀土边坡稳定性分析与锚杆支护参数研究。分析结果表明,裂隙的存在及发展对膨胀土边坡降雨入渗与孔隙水压力分布有显著影响;裂隙开裂越深,表层边坡体越易形成暂态饱和区,同时边坡越趋于不稳定;裂隙发育膨胀土边坡滑坡滑面具有浅层性等特点,锚杆长度、锚固角度、锚固位置等参数变化对降雨下膨胀土边坡安全系数的影响与一般土质边坡有所区别;在分析基础上,提出了合理的锚杆布置方式,以期对膨胀土边坡锚杆布置设计提供建议和参考。

Fissure is an important factor of expansive soil slope instability under rainfall. In order to explore the seepage field characteristics and stability of expansive soil slope under the condition of rainfall, slope saturated and unsaturated simulation is done under 0, 2,4m fissure depth, and the expansive soil slope stability and the bolt support parameters analysis based on limit equilibrium method is carried out. Analysis results show that： the existence and development of fissures of expansive soil slope has significant effect on rainfall infiltration and pore water pressure distribution ; the more depth fissure of slope body, the more easy to form a transient saturated zone, at the same time the more unstable slope; fissure expansive soil slope landslide sliding surface has the characteristics such as shallow features. Parameters change such as anchor rod, anchor length, anchor angle position have different influence on expansive soil slope safety factor under rainfall. On the basis of analysis, the reasonable way of anchor arrangement is put forward, in order to provide anchor arrangement design and reference suggestions for expansive soil slope.