点夯夯沉量分析研究

Analysis of Settling Amount of Point Compaction

深圳某拟建加工厂场区原地形高差大,需平整场地。根据场平填土厚度大的特点,对回填土采用强夯处理,夯击能为4000kN·m,试夯累计夯沉量达到1.45～1.88m。在对夯击数与累计夯沉量的回归、夯击能消耗、夯沉量估算的夯锤底接触应力及压强传递进行分析后得出,夯击数与累计夯沉量呈三次方函数关系;前几夯夯沉量大,以冲切密实浅层土为主,土体压缩消耗能量比例大,后几夯,夯沉量小,能量以增加超孔隙压力和振动波的形式加固深层土体和消散;夯锤与土体作用时间仅为0.06～0.01s,接触应力可达4～20MPa,大部分接触应力为超孔隙压力所承担和传递,因而未破坏土体结构的结论。

The original terrain elevation difference is very large in a factory of Shenzhen. In order to flat ground,the dynamic compaction （4 000 kN· m） was used for consolidation of foundation soil. The tamping compression is up to 1.45-1.88 m depth and tamping compression is a function of cubic. Most of compression is tamped by preceding blow, so the shallow soil is reinforced. Energy increases the excess pore pressure and vibration wave in the form of reinforcement and dissipation of deep soil during the last few hit. The tamping compression is up to 4-20 MPa in a very short contact time （0.06-0.01 s）. So to protect the soil structure,the excess pore pressure commitment and delivery most of impact compresses.