置换率对刚-柔性桩复合地基的影响

Influences of different replacement ratios on composite foundation with rigid-flexible piles

为了研究桩置换率对刚-柔性桩复合地基性能的影响程度,在温州地区进行了多个大型刚-柔性桩复合地基静荷载试验.在静荷载试验中对刚性承压板下压力盒进行同步检测,根据检测成果比较不同置换率下刚-柔性桩复合地基沉降情况,分析置换率对刚-柔性桩复合地基的桩土应力、桩土应力比以及荷载分担比的影响.检测结果表明:复合地基中刚性桩置换率对沉降特性影响较大,增大刚性桩置换率会明显减小沉降.刚-柔性桩复合地基中刚性桩在承载方面发挥重要作用,刚性桩置换率越高作用越明显.复合变形模量随复合地基中桩置换率减小而减小.刚性桩置换率越高,刚性桩承载力发挥度越小,柔性桩承载力发挥度越大,土承载力发挥度越小.

In order to study the influence of pile replacement ratio on the performance of composite foundation with rigid-flexible piles, lots of static load tests were carried out in Wenzhou. Pressure cells beneath bearing plate were monitored in the static load test. On basis of test results, the composite foundation settlement with different replacement ratios was investigated, and the influences of different replacement ratio on stress, pilesoil stress ratio and pile-soil load sharing ratio were analyzed. Test results indicate that the rigid pile replacement ratio influences settlement characteristics largely, and the settlement is reduced obviously with the increment of rigid pile replacement. Rigid pile plays an important role in the load bearing in composite foundation. The deformation module is reduced with reduction of rigid pile replacement ratio. When the pile replacement ratio is higher, the rigid pile bearing capacity display is smaller, the flexible pile bearing capacity display is bigger, and the soil bearing capacity display is smaller.