摘要
目前反射波法桩基动测资料分析主要根据时域内直观分辨,定性评价,其手段过于简单,不能充分利用测试信号内含信息;同时,当原始信号受到"干扰"影响时,该方法有效性大受影响.反射波法桩基动测信号中常见"干扰"信号包括环境及电气噪声、土阻力干扰、桩身浅部缺陷反射信号等.有效信号与各种"干扰"信号的主要区别在于他们的时-频特性不同;通过选择合适的小波基函数对原始信号进行小波分析,实现信号时频分解,可以区分不同物理本质的信号成分,结合场地条件分辨有效信号与干扰信号,再通过对"噪声"时段及频段的抑制,可以实现信号消噪,改善信号质量,从而提高桩基动测资料分析水平.
Pile integrity testing method ,a low strain method for pile integrity testing ,is now widely employed in construction fields.So,the results of the tests must also be accurately evaluated. Now,the interpretations of the pile top velocity traces in time domain is a simple visual inspection of the data by an experienced engineer intuitively and the method is too simplified and can not make full use of the inherent content of the recorders, especially when the recorders are polluted by noises.The noise is usually composed of ambient noise ,electric noise and resistance created by soils around the shaft.The difference between the useful component and the noise of the signal lies in the time-frequent characteristic. The signal are decomposed in the time～frequent domain by use of the spline waveletd of order and, the different type of noise can be differentiated.So, by setting the coefficient of specific time and frequence band to zero, the reconstruction signal can remove the unwaned signal component. It can greatly improve the effect of interpretation about pile integrity testing.
出处
《西安建筑科技大学学报（自然科学版）》
CSCD
2004年第1期25-28,共4页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
陕西教育厅基金项目(02JK124)
关键词
样条小波
桩基
应力波
spline wavelet
pile foundation
stress waves
