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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 ordinary anti-slide piles, the anti-slide piles of anchor rod can greatly reduce the internal force of piles due to the presence of the top anchor rod. However, the calculation method is not yet perfect at present. Therefore, Very necessary. The test results of the failure mode of the anti-slide piles are introduced. The test is carried out in a self-made model box. The model piles are composed of 4 model piles and one anchor rod is arranged at the top of each pile. The load mode is piled up. Force, the model has a certain number of earth pressure inside the box, strain gauge and displacement meter. From the deformation and stress of the pile, the failure of the pile is mainly plastic bending damage, the failure point is located above the front slip surface of the pile, and the failure moment is mainly provided by the anchor rod tension, the pressure of the pile back soil and the soil resistance before the pile ; From the variation curve of anchor rod, the anchor rod force is not completely in the axial tensile state, but in the combined state of bending and axial pulling, the force is mainly located in the range of about 40 cm on both sides of the sliding surface , The stress concentration position is approximately 20 cm on both sides of the sliding surface. From the analysis of strain, the anchor bar first enters the plastic yield state and the second is the pile reinforcement. In addition, after unloading, under the positive tension state , For the pile and anchor bar, the deformation has a certain degree of recovery.