冲刷深度对单桩自振频率影响的试验分析初探  

Preliminary Investigation on the Influences of Scour Depth on Natural Frequencies of a Single Pile

作　　者：贾承岳[1,2] 梁发云[1,2] 王玉[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《结构工程师》2013年第1期114-117,共4页Structural Engineers

基　　金：国家自然科学基金(41172246);中央高校基本科研业务费专项资金资助项目

摘　　要：直接量测基础冲刷深度比较困难,通过桩基振动频率推测冲刷深度是一种可行的方法。采用瞬态激发方式使埋在土中的单桩产生振动,分别利用固定在桩头和埋入土中的加速度传感器记录振动信号。通过改变单桩整体埋深来模拟整体冲刷,在桩周放坡开挖模拟局部冲刷,测试单桩的振动频率,初步得到单桩自振频率随冲刷深度和冲刷形态变化的规律。试验研究表明,单桩自振频率随冲刷深度增加而降低,整体冲刷对单桩自振频率的影响略大于局部冲刷。The scour depth under the waterlevel for bridge piles is difficult to be detected directly. It may be possible ato estimate the scour depth of a single pile through the relations between scouring depth and natural vibration frequency. Single pile vibration was excited by transient excitation and acceleration sensors fixed on pile head and in soil recorded responses. General scour depth was simulated by changing the embedded depth of single pile and the local scour depth is simulated by excavating around the pile step by step. Natural vibration frequencies of the pile were obtained from the data. The relationship between embeded depth and natural vibration frequency was established, which can be used as a reference value for further research. The tests showed that natural frequencies of the single pile reduce with the scour depth increasing ; and the general scour affect the natural frequency of single pile greater than the local scour.

关 键 词：瞬态激振 冲刷 单桩 模型试验 自振频率 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]