增强型预应力混凝土离心桩承载性状对比试验分析
Comparative study on bearing capacity of enhanced pretensioned spun concrete piles and conventional pipe piles
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摘要: 在软土地区,传统管桩存在桩侧摩阻力低、桩身连接方式落后、抗弯抗拉性能差等缺点,其应用有较大的局限性。增强型预应力混凝土离心桩(简称“增强型离心桩”)是在传统管桩基础上开发的一种新桩型。介绍了增强型离心桩的构造、生产工艺和桩身连接方式等,通过单桩静载荷试验表明,与同桩径、同桩长的传统管桩相比,增强型离心桩的单桩竖向极限承载力可达普通管桩的1.23倍,单桩抗拔极限承载力能提高73.3%左右。增强型离心桩通过调整普通管桩桩侧形状,有效发挥桩侧摩阻力,改善桩基承载性能,具有明显的经济效益和社会效益。Abstract: The application of the traditional pretensioned spun concrete pile (TPSCP) is limited in soft soils for its lower shaft resistance, backward connection method, weak bending-resistance and tensile properties. The enhanced pretensioned spun concrete pile (EPSCP) is developed on the basis of TPSCP, and its conformation, construction technology and a set of mechanical bonding joints are introduced. According to the static load tests, the results are as follows: (1) the vertical allowable load capacity of single EPSCP can be 1.23 times as much as that of TPSCP under the same pile diameter and pile length; (2) Compared with that of the TPSCP with the same diameter and length, the vertical ultimate uplift resistance of single EPSCP is increased by 73.3%. It is shown that the shaft resistance of the EPSCP can be improved by setting the ring and longitudinal rib along the pile shaft, and its compressive and tensile characters are ameliorated. So the application of the EPSCP can be extended for its better economic efficiency and social benefits with broad prospects.