滑坡防治独立微型桩性状的大型物理模型试验研究

Large scale model test study on single micropile in landslide reinforcement

通过进行独立微型桩与滑坡相互作用的大型物理模型试验,采用土压力盒、位移计和应变片等测试手段,研究滑坡作用下独立微型桩的受力情况、变形破坏模式及弯矩分布规律等。试验结果表明:独立微型桩的破坏部位位于滑面附近,破坏模式为弯曲与剪切相结合的破坏;滑面上下各15倍桩径的范围内桩土相互作用较明显,此范围外的桩身与周围土体基本共同变形;独立微型桩发生破坏时的桩顶位移量约为1/4倍桩径,且破坏后的微型桩依然有抗滑能力,主要由桩身配筋的拉力提供;独立微型桩的桩身弯矩分布形式不同于普通抗滑桩,弯矩主要分布在滑面附近,且受荷段承受反弯矩。

A large scale model test about single micropile and landslide was carried out.The force,damage form and bending moment of single micropile for landslide reinforcement are studied by several testing tools.The test results show that the damage form of single micropile is cutting and bending failure near the slip surface.The interaction effect between micropile and soil mass is obvious in the scope of fifteen times pile diameters above and down the slip surface,while unconspicuous outside the scope.The displacement of the micropile top is one-quarter of pile diameters when the single micropile damages.The damaged micropile still has skid-resisting capacity which provided by the pulling resistance of the steel.The bending moment of single micropile is different from that of the anti-slide pile.The bending moment of single micropile lies near the slip surface and the pile body above the slip surface effects negative bending moment.