论文部分内容阅读
设计并完成前后排抗滑桩加固滑坡桥基的振动台模型试验。通过输入不同频率、加速度峰值的正弦波,分析振动时桥墩基桩、抗滑桩的受力变形规律,以及PGA放大系数变化特性。试验结果显示,当滑体为可塑的粉质黏土时,后排抗滑桩桩后土压力峰值分布随台面加速度峰值变化,由三角形逐渐变为倒三角形;由于桥墩、后排抗滑桩间距很小,两者相互作用增强,桥墩基桩受到较大的动力荷载影响,随着台面振动加速度峰值增加,桥墩基桩的应变最大值从桩顶下移至滑面附近;当正弦波加速度峰值相等时,频率越高,土体黏滞阻尼越小,滑坡的PGA放大系数越大,相应云图呈层状分布,同时高频振动波使土体产生较小的位移和变形,导致滑坡推力也较小;振动波在向上传播时,土体存在滤波效应,自振频率附近的频谱幅值会被放大。
Design and Implementation of Shaking Table Model Test of Anti - Slide Piles Reinforced Landslide Bridge Foundation. Through the input of sine wave with different frequency and peak acceleration, the force and deformation of bridge pier pile and anti-slide pile during vibration are analyzed, and the variation characteristics of PGA amplification coefficient are analyzed. The test results show that when the slide body is silty silty clay, the peak pressure distribution of rear soil anti-slide pile changes with the change of the peak acceleration of the platform, and the triangle gradually becomes the inverted triangle. Because of the pier, The interaction between the two is stronger and the pile foundation subjected to greater dynamic loads. As the peak acceleration of the deck increases, the maximum strain of the bridge pile foundation moves downward from the pile top to the sliding surface. When the peak acceleration of the sine wave is equal , The higher the frequency is, the smaller the soil viscous damping is. The larger the PGA amplification coefficient of the landslide, the corresponding cloud pattern is layered distribution. At the same time, the high-frequency vibration waves cause smaller displacements and deformations of the soil, resulting in more landslide thrust When the vibration wave propagates upward, there is a filtering effect on the soil, and the amplitude of the spectrum near the natural frequency will be amplified.