低能级强夯在安哥拉Quelo砂中的应用

针对安哥拉具浸水软化和湿陷的Quelo砂，采取不同夯击能（1 000、2 000 kN·m）和不同工况（天然、最优含水率）4种组合方案进行强夯加固对比试验，分析了强夯前、后各试验场地Quelo砂干密度、孔隙比、重型动力触探击数以及湿陷系数等指标的变化规律，提出了Quelo砂地基土在不同工况下的强夯影响深度、有效加固深度建议值和修正系数a。试验结果表明，在增湿的条件下较低能级强夯时Quelo砂的物理力学指标虽然能够显著提高，但湿陷性消除不明显，夯击能足够高时湿陷性才能够进一步被消除，增湿条件下消除Quelo砂湿陷性的强夯施工存在一个夯击能阀值。

Application of low energy level dynamic compaction method to Angola Quelo sand

This study conducted a series of indoor and outdoor tests on Quelo sand in Angola, which has the characteristics of water softening and collapsibility. Four combination schemes with different levels of tamping energy(1 000, 2 000 kN·m) and different working conditions(natural, optimal moisture content) are adopted to carry out comparative consolidation tests. The variation rules of dry density, void ratio, heavy dynamic penetration number DPT(N63.5) and collapsibility coefficient of Quelo sand before and after dynamic compaction are analyzed. Furthermore, Suggested values of the impact depth, the effective reinforcement depth and the correction coefficient α of Quelo sand are proposed under different dynamic compaction programs. The experimental results show that although the physical mechanics indexes of Quelo sand can be significantly improved with the lower tamping energy level under the condition of humidification; however, its collapsibility can not eliminated obviously. Only when the tamping energy is high enough, the collapsibility of Quelo sand can be further eliminated. And there is a threshold of tamping energy in the dynamic compaction for eliminating the collapsibility of Quelo sand under humidification conditions.