深厚砂性土地基竖向高频振动致密机理及地基加固设计

高频振动致密是一种地基处理的新技术。该法应用高频振动锤在振动探杆顶施加竖向激振力,在振动杆轴周围产生剪切波(S波)及压缩波(P波),在高频振动力的作用下,土体中的振动探杆由此上下反复振动,在S波和P波的作用下,最终逐步地提高其周围土体密实度。在详细介绍该法的加固机理、施工原理以及与振冲法区别的基础上,提出适用于该法处理的土质条件并采用颗粒离散元分析结果进行分析说明以及相应的设计和检测方法。最后指出了该技术有待于进一步研究的几个理论问题。

MECHANISM AND DESIGN METHOD OF GROUND IMPROVEMENT BY RESONANCE COMPACTION METHOD

The resonance compaction method(MRC),using high frequency hydraulic vibratory hammer and MRC compaction probe,is one of the most efficient way of vibratory compaction method for deep granular soils.The probe is oscillated in the vertical direction and the vibration energy is transmitted to the surrounding soil along the entire probe surface.Then soils compaction is caused by vertically polarized shear waves.In the paper,mechanism of high frequency deep vibratory compaction method for deep granular soil densification was studied.Mitchell’s method,which classified soils with respect to the grain size distribution,and Massarsch’s method based on the cone penetration test,were modified to preferably assess the compactability of deep granular soil.The design method of construction scheme was put forward for MRC.