滑坡防治格构梁锚固系统振动台模型试验  

Shaking table model test for framed anchors in landslide prevention

作　　者：汪班桥[1] 李楠[1] 门玉明[1] 张妙芝 WANG Ban-qiao, LI Nan, MEN Yu-ming, ZHANG Miao-zhi(School of Geology Engineering and Geomatics, Chang＇an University, Xi＇an, Shaanxi 710054, Chin)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《岩土力学》2018年第3期782-788,796,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.41440021);中央高校基本科研业务费专项资金项目(No.2014G1261049)~~

摘　　要：为研究地震作用下锚固系统的动力响应,采用振动台进行格构梁锚杆支护滑坡模型试验。试验分别输入汶川波、EL Centro波、正弦波作为地震激励,监测锚杆轴力、坡体加速度和位移时程,研究锚固滑坡在地震作用下的动力响应差别、不同位置锚杆在地震作用下的受力机制。结果表明:低量级地震波(0.05 g^0.40 g)作用下,坡脚相对坡体的其他部位,浅表效应表现明显,坡脚滑面由于反复的揉搓作用,更容易出现裂缝,影响整个锚固体的稳定;建议在拟静力法设计的基础上,在滑坡坡脚密集地打入短锚杆或土钉以平衡坡脚滑面处出现的不协调往复运动。高量级地震波作用(0.6 g^0.8 g)下,坡肩处坡表效应表现明显、坡顶滑面处裂缝宽度不断增长,更易出现崩裂、崩滑等现象;建议加长坡顶的第1排锚杆,以抑制坡顶滑面处裂缝的下切发展;同时在坡顶面垂直地打入短锚杆或种植根系发达的植物护坡。格构梁锚固系统不会出现素土边坡的整体性破坏,强震作用下,首先是坡脚锚杆的承载能力受到损伤,顶层锚杆的抗拉力则因坡顶面及上表面的拉裂急剧增长。研究结果为更加合理地进行锚杆抗震设计提供了良好的基础。In order to study the dynamic responses of anchorage system under earthquake,the model of landslide supported by anchor bars and lattice beam is carried out using shaking table. The difference of dynamic response of anchor bars in different locations and the mechanism behavior of anchor bars under earthquake are studied by inputting waves of Wenchuan earthquake, EL Centro earthquake and sine seismic wave to monitor the axial force of anchor bars, landslide acceleration and landslide displacement. The results suggest that under low level earthquake loading（0.05 g^0.40 g）, the surface effect of slope toe is more obvious than other parts of the landslide, and the sliding surface near slope toe is prone to fracturing because of repeated rubbing and cutting. Based on pseudo-static method design, it is advised that short anchors or soil nails should be driven into toe slope in order to balance the uncoordinated reciprocating motion of sliding surface near slope. Under high level earthquake loading（0.6 g^0.8 g）, the surface effect of slope shoulder is more obvious, the fracture in sliding surface near slope top is longer and wider than before, and the sliding surface is more likely to crack or collapse. It is advised that the first-row anchors should be extended in order to restrain the development of cracks in slope sliding surface. Meanwhile, using short anchors or growing plants with developed root system at top of the slope is necessary to protect the slope. Slope with anchorage system is not prone to as-a-whole slope damage like plain soil slope, and under high level earthquake loading, firstly anchors in slope toe are damaged, and then tensile force of top anchors sharply rises due to cracks caused by pulling force at the top surface of slope. The results provide a reasonable foundation for the design of anchor bars under earthquake.

关 键 词：滑坡 锚固系统 地震作用 动力响应 振动台试验 

分 类 号：P642[天文地球—工程地质学]