厚壁蝶形弹簧用于基桩动力测试的技术研究

Technical Research on Thick Wall Belleville Spring for Dynamic Testing of Foundation Piles

针对基桩高应变动力试桩法应力测试环节中存在的混凝土非线性造成应力测试失真,采用组合锤时测力方法信号存在信号尖刺多、峰值异常的问题,研制了一种通过将蝶形弹簧安装在桩顶上,应变传感器安装在蝶形弹簧上,加速度传感器安装在桩头上,测试重锤在冲击过程中蝶形弹簧的应变,通过压力机标定试验的结果,转换为高应变桩身应力的技术,可以有效避免传统高应变测试过程中由于混凝土开裂或出现严重塑性变形导致力信号失真以及组合锤锤上测力信号异常的情况。

Aiming at the distortion of the stress test caused by the nonlinearity of concrete in the stress test link of the high strain dynamic pile test method of the foundation pile,and the problem of many signal spikes and abnormal peaks in the signal of the force test method when the combined hammer is used,a method is developed to test the strain of the butterfly spring during the impact process by installing the butterfly spring on the pile top,installing the strain sensor on the butterfly spring,and installing the acceleration sensor on the pile head,The technology of converting the results of the press calibration test into the high strain pile stress can effectively avoid the distortion of the force signal caused by the concrete cracking or serious plastic deformation in the traditional high strain test process and the abnormal situation of the force signal measured on the combined hammer.