Abstract

Junked tires encased slags pile composite foundation (JTES pile composite foundation for short) is a new method for treating soft soil ground. To study the vertical load-settlement characteristics and load-transfer mechanism of JTES pile composite foundation, vertical static load comparison tests in different loading conditions were investigated herein. The test results show that, the load-settlement curve of the JTES pile composite foundation changed slowly. And compared with the uncovered equal section slag pile composite foundation and natural foundation, its ultimate bearing capacity increased about 22.2% and 57.1%, respectively. While settlement of JTES pile composite foundation was reduced by 12.2% and 23.1% compared to that of the other two foundations. The axial force and lateral friction resistance of JTES pile were abruptly changed. The abrupt change rates of axial force of JTES piles were 35.4%, and the lateral friction with change rate of 40.8%. The pile-soil stress ratio of the JTES pile composite foundation was in 2 ∼ 4. Then, the calculated settlements of JTES pile composite foundation were proposed. The difference between model test results and calculation values was about 10%. The results can provide important references for the design and construction of JTES pile composite foundation in soft soil improvement.

摘要

废旧轮胎包渣桩复合地基（简称JTES桩复合地基）是一种处理软土地基的新方法。为研究JTES桩复合地基竖向荷载沉降特性及荷载传递机理，开展了不同荷载工况下的竖向静荷载对比试验。试验结果表明，JTES桩复合地基的荷载-沉降曲线变化缓慢。与裸露等截面矿渣桩复合地基和天然地基相比，其极限承载力分别提高了约22.2%和57.1%。而JTES桩复合地基的沉降量较其他两种地基分别降低了12.2%和23.1%。JTES桩的轴力和侧摩阻力发生突变。JTES桩轴力突变率为35.4%，侧摩力突变率为40.8%。JTES桩复合地基的桩土应力比为2∼4，提出了JTES桩复合地基的沉降计算方法。模型试验结果与计算值相差约10%。研究结果可为软土改良中JTES桩复合地基的设计与施工提供重要参考。