为探究h型桩加固边坡的动力响应及破坏特征,本文以四川康定某铁路沿线堆积体边坡为原型,开展大型振动台模型试验,探究了坡体在多次地震作用下其加速度和频谱响应规律,分析了强震作用下加固边坡的破坏模式及桩身破坏特征.结果表明:随地震荷载强度增大,边坡内部及坡表加速度均沿高程表现出不同程度放大效应;基岩与滑体发生不协调变形,进而导致其傅里叶频谱的响应差异增大;h型桩加固边坡表现出张拉-剪切-滑移式的复合破坏模式;在 h 型桩支护体系中,h型桩横梁与短桩连接处为薄弱点,1～3 号桩体均在此处发生损伤破坏;边缘桩体对内部结构具有支撑和约束作用,降低了内部桩的破坏;相较于传统抗滑桩,h型桩破坏后,其后排桩仍能提供抗滑力,支护体系表现出一定的残余支护能力.
Study on Dynamic Response Characteristics and Failure Mode of h-Type Pile Reinforced Slope
In order to explore the dynamic response and failure characteristics of the slope reinforced by h-type piles,a large-scale shaking table model test was carried out based on the accumulation slope along a railway in Kangding,Sichuan Province.The acceleration and spectral response of the slope under multiple earthquakes were explored,and the failure mode and pile failure characteristics of the reinforced slope under strong earthquakes were analyzed.The results show that with the increase of seismic load intensity,the acceleration in the slope shows different degrees of amplification effect along the elevation with that at the slope surface.The uncoordinated deformation of bedrock and sliding body leads to the increase of the response difference of Fourier spectrum.The h-type pile reinforced slope shows a tensile-shear-slip composite failure mode.In the h-type pile support system,the connection between the h-type pile beam and the short pile is a weak point.The No.1～3 piles in the model test are damaged in this mode.The edge pile has a supporting and restraining effect on the internal structure,which reduces the damage of the internal pile.Compared with the traditional anti-slide pile,the rear row pile can still provide anti-slide force after the h-type pile is destroyed,and the support system shows a certain residual support capacity.
shaking tableside slope supporth-type piledynamic responsemode of failure
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