压力型锚杆支护滑坡的地震动力响应特性研究

STUDY ON DYNAMIC RESPONSE OF LANDSLIDE SUPPORTED BY PRESSURE-TYPE ANCHOR UNDER EARTHQUAKE

为研究地震作用下锚固滑坡的动力响应特征及压力型锚杆的受力机制,采用ABAQUS有限元软件建立了压力型锚杆联合格构梁支护的锚固滑坡模型,在此基础上,分析了锚固滑坡的加速度响应规律、地震动参数对加速度响应的影响以及压力型锚杆的受力特征等。结果表明:地震作用下锚固滑坡具有明显的高程放大效应,坡顶响应最强;不同类型的地震波作用时,由于其频谱特性的差异,锚固滑坡的加速度响应不同,锚固滑坡对输入地震波的低频段存在放大作用,对高频段具有滤波作用;随地震波幅值的增大,锚固滑坡的加速度响应呈先减小后增大的趋势。对于同一根锚杆而言,锚杆杆体轴力分布较均匀;对于同列不同排的锚杆而言,各排锚杆杆体的轴力值差异较大,自上而下呈"C"型分布,底排锚杆和顶排锚杆承担大部分荷载。研究结果对于压力型锚杆支护滑坡的抗震设计具有一定的指导意义。

In order to study dynamic response of anchorage landslide and mechanical behaviors of pressure-type anchor under earthquake, the finite element software ABAQUS was adopted and an anchorage landslide model supported by pressure-type anchor and lattice beam was established. On that basis, the acceleration response law of anchorage landslide, the effect of ground motion parameters on acceleration response of the model, and the mechanical behaviors of pressure-type anchor under earthquake were researched respectively. The results indicated that anchorage landslide had elevation amplification effect from bottom to top along with the landslide, and the acceleration response in crest was the strongest. Due to the spectrum characteristics of earthquake, acceleration response is different under different seismic waves. The anchorage landslide had an amplifying effect on lower frequency band and an attenuation function on higher frequency band. With the increase of loading amplitude, the acceleration response of anchorage landslide decreased first and then increased. For the same anchor, axial force distribution was nearly uniform; however, for the anchors at different elevation, axial force of anchors had a great difference, and the strain distribution of anchor body shows the “C”-type from bottom to top. The bottom anchor and the top anchor bear most of the loads. The research results could provide a reasonable foundation for the design of the pressure-type anchor under earthquake.