多头夯扩桩扩大头夯扩影响范围研究

Study on Tamping-enlarging Scope of Influence by Expanded End of Rammed Pedestal Pile

多头夯扩桩的承载力由桩侧摩擦力、桩身扩大头承载力和桩端扩大头承载力构成,主要以桩身扩大头承载力和桩端扩大头承载力为主;而夯扩提高扩大头阻力的作用范围集中在夯扩加密土的影响半径之内。扩大头夯扩影响土体范围是很难直接确定的。笔者通过室内模型试验对砂土中多头夯扩桩扩大头的影响范围进行了研究。得出了以下结果:扩大头形状为近似圆球形状或腰鼓形,其夯扩挤密影响范围类似于球体状;扩大头下方的挤密效果最佳,很大程度上提高了地基土体承载能力。

The bearing capacity of Ram-compaction Multiple Expanded Pedestal Piles is composed of pile side friction force, the pile head expansion head bearing capacity and the pile end expansion bearing capacity, mainly to the pile head to expand the head bearing capacity and the pile end to ex the head bearing capacity：The scope of the expansion of the head resistance is concentrated within the head pand the radius of influence of the rammed soil. It is difficult to directly determine the extent of the affected soil. In this paper, the influence of the indoor model test on the influence of the expanded head of Ram- compaction Multiple Expanded Pedestal Piles in the sand was studied. It obtained that the expanded head shape was approximate sphere shape or drum shaped, the compaction of impact compaction range was similar to the sphere shape： the compacting effect expanded the head at the bottom was best, which greatly improved the bearing capacity of foundation soil.