高速铁路螺杆桩复合地基桩侧摩阻力原位试验研究

结合太焦高速铁路螺杆桩复合地基工程,开展螺杆桩复合地基桩侧摩阻力原位测试试验,通过分析获得的螺杆桩单桩静荷载-桩顶沉降曲线以及桩身内力分布曲线,研究高速铁路复合地基中螺杆桩侧摩阻力演化规律及螺杆桩的荷载传递过程。结果表明:螺杆桩-土接触面荷载传递过程可划分为弹性、弹塑性和极限状态3个阶段,弹性阶段桩侧摩阻力比小于等于0.5,弹塑性阶段桩侧摩阻力比为0.5~0.7,极限状态阶段桩侧摩阻力比为0.7~1.0;螺杆桩直杆段和螺纹段侧摩阻力演化规律为,在弹性阶段螺纹段侧摩阻力小于直杆段侧摩阻力,在弹塑性阶段螺纹段侧摩阻力接近直杆段侧摩阻力,在极限状态阶段螺纹段侧摩阻力大于直杆段侧摩阻力。

In-Situ Test Study on Lateral Friction of Screw Pile Composite Foundation of High Speed Railway

In-situ tests on the lateral friction of screw pile composite foundation were performed on Tai-Jiao high speed railway in order to investigate the evolution of the lateral friction and load transfer process of screw pile in high speed railway composite foundation by analyzing the obtained static-load and pile top settlement curve of single screw pile and the internal force distribution curve of pile body.Results show that the load transfer process of the pile-soil interface of screw pile can be divided into three stages as elastic stage,elastic-plastic stage and limit state stage.In elastic stage,the lateral friction ratio of screw pile is less than or equal to 0.5.In elastic-plastic stage,the lateral friction ratio of screw pile is 0.5~0.7.In limit state stage,the lateral friction ratio of screw pile is 0.7~1.0.The evolution for the lateral fiction of the straight and threaded sections of screw pile can also be divided into three stages.In elastic stage,the lateral fiction of the threaded section is less than that of the straight section.In elastic-plastic stage,the lateral friction of the threaded section is very close to that of the straight section.In limit state stage,the lateral friction of the threaded section is larger than that of the straight section.