Under the impact of a large hammer, a high signal noise ratio of the force and velocity can be acquired in the high-strain dynamic testing. 高应变动力试桩法采用数吨重锤锤击，同时实测了桩顶的力信号和速度信号，具有很高的信噪比。
Free falling heavy rammer was used in former piling constructions, but the piling depth and pile pipe diameter were comparatively small. 在以往的施工中采用重锤下落打桩，打桩的深度和桩管的直径都比较小。
