地震作用下压力型锚杆格构梁破坏特征试验

发布时间：2018-06-27 10:30

本文选题：道路工程 + 边坡锚固系统　；参考：《中国公路学报》2017年05期

【摘要】：为研究强震作用下边坡锚固系统的抗震作用及破坏特征,采用振动台模型试验,分别输入汶川波、EL-Centro波、正弦波作为地震激励,监测坡体加速度、锚杆和格构梁的应变,研究加固滑坡在强震作用下的动力响应差异以及不同位置锚杆和格构梁在地震作用下的受力特征。结果表明:强震作用下,坡脚剪切松弛区的形成导致坡脚首先进入塑性区,坡脚锚杆的承载能力受到影响,坡脚处的横梁出现拉弯变形;由于潜在滑面的存在,坡体上部土体易发生张拉破坏,坡顶首层锚杆受拉作用增强,中上部的格构梁和锚杆存在明显的不协调性,坡顶的首层横向格构梁发生拉弯变形;与横梁相比,竖梁的弯应变较小,各层的应变差值不大,与锚杆的协调性较好;建议在拟静力法设计的基础上,在锚固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;加长设计坡顶的第1层锚杆,以抑制坡顶滑面处的拉张裂缝;同时在坡体顶面垂直地打入短锚杆、微型桩或种植根系发达的植物护坡,且在格构梁设计时应多考虑横梁的拉弯变形。
[Abstract]:In order to study the earthquake resistance and failure characteristics of slope Anchorage system under strong earthquake, the vibration table model test was used to input Wenchuan wave EL-Centro wave and sine wave as seismic excitation to monitor the slope acceleration, the strain of anchor rod and lattice beam. The difference of dynamic response of reinforced landslide under strong earthquake and the stress characteristics of anchors and lattice beams in different positions under earthquake are studied. The results show that under strong earthquake, the formation of shear relaxation zone at the foot of the slope leads to the first entry of the slope foot into the plastic zone, the bearing capacity of the anchor rod at the foot of the slope is affected, and the beam at the foot of the slope is subjected to tension and bending deformation, due to the existence of the potential sliding surface. The soil in the upper part of the slope is prone to tensile failure, the tensile action of the anchors at the top of the slope is enhanced, the lattice beam and the anchor rod in the middle and upper part of the slope are not in harmony, and the transverse lattice beam of the top of the slope is subjected to tensile bending deformation, which is compared with the transverse beam. The flexural strain of vertical beam is small, the strain difference of each layer is small, and the coordination with anchor is better. It is suggested that based on the design of pseudostatic method, The short anchor rod or soil nailing is used to balance the incongruous reciprocating movement at the sliding surface of the slope foot, and the first layer anchor rod of the slope top is extended to restrain the tension crack of the slope top slide surface. At the same time, the short anchor rod, micro-pile or plant with developed root system should be inserted vertically on the top of the slope to protect the slope, and the strain of the beam should be considered in the design of the lattice beam.
【作者单位】：长安大学地质工程与测绘学院;
【基金】：国家自然科学基金项目(41440021,41102177) 中央高校基本科研业务费专项资金项目(310826175029)
【分类号】：U416.14

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