东非珊瑚礁砾砂地区PHC桩静载荷试验研究

Static Load Test of PHC Piles Constructed in Coral Reef Gravel Area in East Africa

珊瑚礁砾砂层在肯尼亚、坦桑尼亚等东非国家普遍存在,且埋藏较浅。该地区某水工项目为高桩梁板式结构,采用PHC桩作为桩基础。通过对项目桩长45 m、桩径800 mm;桩长39 m、桩径1 000 mm的2根PHC试验桩进行沉桩规律总结,并对试验桩进行高应变测试、海上锚桩法压桩静载荷试验、拔桩试验和侧摩阻力试验,探讨了珊瑚礁砾砂岩层PHC桩基桩的持力层选择、压向/拔向侧阻力折减系数及与规范中的强风化软质岩侧阻力值对比,为该地区PHC桩沉桩施工及理论研究提供指导。

Coral reef gravel layer is widely distributed at shallow depth in such East African countries as Tanzania and Kenya.Based on a PHC piled structure on beam and slab built in the above area,pile-driving rules are summarized by testing a 45 m×800 mm PHC piles and a 39 m×1000 mm PHC piles,completed with high-strain test,static load test of offshore anchor pile,tensile pile test and side-friction resistance test.Analysis is carried out for the selection of supporting layer for PHC foundation pile driven into coral reef gravel stratum,lateral resistance reduction coefficient in pressing and pulling direction in comparison with that of strongly weathered soft rock specified in the related standard.The results will guide the construction and theoretical research of PHC pile construction in this area.