嵌岩桩竖向荷载性能分析及设计

The Analysis of Vertical Load Bearina Capacity and Design of Socketed Pile

就《桥规》中嵌岩桩承载力计算公式的一些不足之处进行了探讨,提出了改进的计算公式。改进公式中将覆盖土层的摩阻力作为单桩承载力的一部分,并在计算嵌固力和端阻力时,采用了与《桥规》相异的修正系数,它们考虑了桩的长细比、桩底岩土的影响,即给出了桩的嵌固力和端阻力随嵌岩深度变化而需要的修正。因而该式比《桥规》提供的嵌岩桩计算公式更为合理、经济,同时可加快工程的施工进度。

Combining the author’s practical experience, According to chorfcoming of some specification, the improved calculating formula of rock-embedded pile’s bearing capacity, ure proposed then analyzed influencing factors per parameter in formula. In the improved formula, the soil’s friction force around pile was regarded as a part of pile’s bearing capacity. And when calculating embedded force and end-bearing force, the formula adopted the correction coefficients that were differ from the standard. The correction coefficients took into account for slenderness ratio of pile and rock state in the bottom of pile, that is to say the correction coefficients presented the improvement of change for embedded force and end-bearing force following the socketed length. So the improved formula was more economic and reasonable than the formula provided by JTJ024-85. In the end, combining the pile’s design information of Shuanghekou bridge, the paper adopted two methods, the formula provided by JTJ024-85 and the improved formula, to do the calculation of pile’s socketed length and bearing capacity, and analyzed the results. The socketed length could be shortened effectively. So it could greatly cut the pile’s length, decreased the concrete used, reduced the work of piles and quickened the construction.