刚-柔性桩复合地基中桩荷载传递规律试验研究

为了解刚-柔性桩复合地基中刚性桩和柔性桩的荷载传递规律，在温州地区选择了2幢采用刚-柔性桩复合地基的建筑物进行原位试验。试验前在钻孔灌注桩桩身埋设了钢筋应力计，在水泥搅拌桩桩身埋设了振弦式应变计，在建筑物施工过程中同步检测传感器的变化情况。试验结果表明，不同部位及不同类型桩荷载传递规律不同，中部刚性桩摩阻力相对于边部刚性桩重心下降，刚性桩荷载传递长度大于柔性桩。无褥垫层刚-柔性桩复合地基中部刚性桩在层数低时会出现负摩阻力，有褥垫层刚-柔性桩复合地基中在施工期间始终存在负摩阻力。中部桩端承力要高于边部桩端承力。

Research on in-situ tests of pile load transfer behaviors in composite foundation with rigid- flexible piles

In order to study load transfer mechanism of rigid pile and flexible pile in composite foundation with rigid-flexible piles, in-situ tests are carried out for the two buildings with this new composite foundation in Wenzhou. Stress meters are embedded along cast-in-place pile shaft; and strain meters are embedded along cement mixing pile shaft. Sensors are monitored in the process of construction. The test results show there are different rules between rigid pile and flexible pile; the gravity central point of central rigid pile friction force is lower than that of edge rigid pile; central rigid pile in composite foundation without cushion appears negative friction force at few floors; while central rigid pile in composite foundation with cushion has negative friction force throughout construction. Furthermore, central pile bearing capacity at pile tip is larger than that of edge pile.