【摘要】 通过大型振动台试验,对滑面附近位置处的动土压力峰值分布规律进行了分析。由于地震信号具有持时短、非平稳性等特点,为分析其在不同频带的动力响应情况,利用小波包分析频带划分均匀能力和时频局部化性质,对水平向加载的El波进行了分解,从而对其频谱特性进行了研究。试验结果表明:滑面附近位置处动土压力常常最大,且动土压力在沿桩身高度25 cm及45 cm处均出现了突变,在实际工程中应重点关注这两个位置;对微型桩动土压力影响较大的频段主要为第一频带(0.1～6.26Hz)和第二频带(6.26～12.51Hz),在工程应用中应避免这两个频带的地震波与微型桩发生共振;沿桩身高度25 cm处,后排微型桩山侧及河侧的动土压力值均要大于前排微型桩山侧及河侧的动土压力值;而在沿桩身高度45 cm处,前排微型桩山侧及河侧的动土压力值均要大于后排微型桩山侧及河侧的动土压力值。更多还原

【Abstract】 Through the large-scale shaking table test,the distribution of peak pressure near the sliding surface was analyzed.The seismic signal has the characteristics of short duration and non-stationarity.Based on the characteristics,the horizontal-loaded El waves were decomposed to analyze the dynamic response in different frequency bands by using wavelet packet analysis,which has the properties of uniform frequency band division and time-frequency localization.The test results show that the dynamic soil pressure is usually highest at the position near the sliding surface.Moreover,the dynamic soil pressure is abrupt at the heights of 25 cm and 45 cm along the pile body,respectively,which should be paid attention to in practical engineering.The frequency bands those greatly affect the dynamic pressure of micro-piles are the first frequency band(0.1-6.26 Hz)and the second frequency band(6.26-12.51 Hz).In the engineering application,the resonance between the seismic waves in these two frequency bands and the micro-piles should be avoided.At 25 cm of pile height,the dynamic soil pressure values on the hill and river sides of micro-piles at the rear row are higher than those of micro-piles in the front row,while at 45 cm of pile height,the dynamic soil pressure values on the hill and river sides of micro-piles in the front row are higher than those of micro-piles at the rear row.更多还原