带承台单桩动刚度的试验研究

采用激振法和冲击激励法对广州珠江电厂燃气(LNG)联合循环工程4根带承台的冲孔灌注桩进行现场试验,试验内容包括:单桩竖向、单桩水平-旋转耦合受迫振动试验和自由扭转振动。根据现场试验的结果,给出单桩抗压动刚度、抗剪动刚度、抗弯动刚度、抗扭动刚度和单桩扭转振动、单桩竖向振动和水平-回转耦振动的阻尼比的测试结果。同时,研究带承台单桩动刚度和阻尼比随桩长的变化规律,为大型动力机器基础的振动和隔振设计提供技术依据。但在现场试验时,因周围环境对测量结果有一定的干扰,为了能有效地去除环境干扰和其他模态的影响,使测试数据可靠,采用跟踪滤波、平均和模态识别技术,大大提高测试数据的精度和可靠性。

EXPERIMENTAL STUDY ON DYNAMIC STIFFNESS OF SINGLE PILE WITH CUSHION CAP

The vertical pressure tests and horizontal torsion tests for four boring piles with cushion cap at a Guangzhou Power Plant by vibrate-excitation are performed;and the compressive stiffness,shear stiffness,bending stiffness and torsion stiffness of single pile are analyzed.The achieved results can provide a technical base for vibration and vibration isolation design of great dynamical machine foundation,adopting the tracking filtering,average and modality identification technique.During the in-situ testing,for the negative effects of the ambience,the tracking filtering,average,and summation modality identification techniques are adopted to remove the interferences of the ambience and other negative effects.Therefore,the precision and the reliability of the test data can be improved effectively;and the test data are validated.