锚杆抗滑桩破坏模式的试验研究  

Experimental study on failure modes for anti-slide piles with a single anchor

作　　者：李寻昌[1,2] 门玉明[1,2] 张涛[1] 刘洪佳 严静平[1] 

机构地区：[1]长安大学地质工程与测绘工程学院安全工程系,陕西西安710054 [2]西部矿产资源与地质工程教育部重点实验室,陕西西安710054

出　　处：《岩土工程学报》2011年第5期803-807,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(40272116);国土资源大调查项目(1212010914021);中央高校基本科研业务费专项(CHD2010JC058);长安大学基础研究支持计划专项基金资助;西部矿产资源与地质工程教育部重点实验室资助

摘　　要：与普通抗滑桩相比,锚杆抗滑桩由于桩顶锚杆的存在,虽可以极大减小桩身内力,但其计算方法目前还不是很完善,因而开展这方面的试验研究就显得十分必要。介绍了锚杆抗滑桩破坏模式的试验成果,试验在自制的模型箱内进行,模型桩共4根,每根桩顶均布设一个锚杆,加载方式采用堆载,为了获得桩体变形和受力,模型内部设有一定数量的土压力盒、应变片和位移计。从桩体变形和受力来看,桩的破坏主要为塑性弯折破坏,破坏点位于桩前滑面以上,破坏弯矩主要由锚杆拉力、桩背土压力和桩前土体抗力来提供;从锚杆变化曲线来看,锚杆受力并不完全处于轴向受拉状态,而是处于弯曲和轴拉这两种的组合状态,受力主要位于滑面两侧40 cm左右的范围内,应力集中位置大致位于滑面两侧20 cm位置处;从应变分析来看,锚杆钢筋首先进入塑性屈服状态,其次才是桩体钢筋;另外,卸载后,在正的受拉状态下,对于桩体和锚杆钢筋,变形均有一定程度的恢复。Compared with common anti-slide piles,the anchor on the top of a new kind of pill anti-slide piles with a single anchor can greatly reduce their internal forces,but the calculation method is not perfect at present.Thus the experimental study on the anti-slide piles with a single anchor is necessary.The results from experiments on failure modes for the anti-slide piles with a single anchor are introduced.The tests are conducted in a self-made model box.There are four model piles with anchors on their top,and loading method is heaped load.In order to obtain the pile deformation and stress,a number of earth pressure boxes,strain gages and displacement meters are arranged inside the model.From the angle of the pile deformation and stress,the failure point lies above the sliding surface,and breaking bending moment is mainly supplied by the pulling forces of anchors,the soil pressure from the back of the piles as well as the soil resistance from the front of the piles.From the changing curve of the anchor,the stress is from the combinations of bending and axial tensile,not completely in axial tensile condition.The range of stress is mainly around 40 cm at both sides of slipping surface with stress concentration of 20 cm at both sides.From the analysis of strain,the anchor steel is the first in the plastic yield state,and the pile body steel follows.In addition,there is a certain recovery of deformation for pile body and anchor steel under the forward tension condition after unloading.

关 键 词：锚杆抗滑桩 试验研究 破坏模式 塑性弯折破坏 

分 类 号：TU473.1[建筑科学—结构工程]