过厚层填土嵌岩桩承载力性状试验研究

为研究过厚层填土嵌岩桩承载力相关特性，本文以南宁市第三中学国际学校工程为依托，对两根嵌岩桩进行现场静载荷试验，分析了试桩桩身轴向力、桩身侧摩阻力和桩端阻力随荷载的变化规律。试验结果表明：当试桩顶部有竖向荷载时，桩周土岩层的侧摩阻力和桩端岩层的端承力共同构成嵌岩桩承载力。随着深度的增大，试桩截面轴力渐渐减小，当桩顶的荷载越大时，相应轴力递减速率也更快。在过厚土层中，成桩充盈系数偏大，中风化粉砂岩端阻力占总加载量比重小，因此施工过程应严格控制泥浆护壁的泥浆稠度，加强沉渣厚度检测，并建议采用桩底注浆技术，以保证端阻的充分发挥。

Experimental Study on Bearing Capacity of Rock-Socketed Piles Covered by Overfilled Soil

In order to study the characteristics of bearing capacity of rock-socketed piles covered by overfilled soil, this paper carries out static compression tests on two rock-socked piles in the project of Nanning No.3 Middle School international school, and analyzes the variation law of axial force, lateral friction resistance of pile body and resistance of pile tip with load. The test results show that the lateral friction resistance of the soil layer around the pile and the end bearing capacity of the pile tip together constitute the bearing capacity of the rock-socketed pile with the vertical load. As the depth increases, the axial force of the test pile gradually decreases. When the load on the pile top increases, the corresponding axial force decreases faster. In overfilled soil, pile filling coefficient is relatively large, and the end resistance of medium-weathering siltstone occupies a small proportion of the total loading load. Therefore, during the construction process, the mud thickness of the mud retaining wall should be strictly controlled, and the detection of sediment thickness should be strengthened. it is suggested that the grouting technology of pile bottom should be adopted to give full play to the resistance of pile tip.