肯尼亚珊瑚礁灰岩地区钢管桩终锤标准

Stopping criteria for steel pipe piles in coral reef limestone area of Kenya

针对肯尼亚珊瑚礁灰岩地区某水工项目钢管桩原设计收锤标准与施工情况不符的问题,进行新收锤标准下沉桩规律的研究,采用海利公式理论计算、高应变试验及锚桩法静载荷试验方法,并结合项目1440根基桩的实际沉桩工作,得出钢管桩在珊瑚礁灰岩地区的推荐收锤标准:1)珊瑚礁灰岩地区钢管桩沉桩施工时收锤控制推荐采用贯入度控制为主、设计桩尖高程为辅的原则;2)打入式开口钢管桩施工,采用锤芯质量20 t、锤芯跳高1.2 m时,φ1 200 mm×12 mm、φ1 200 mm×18 mm、φ1 200 mm×24 mm钢管桩推荐收锤贯入度分别为12~18、7~10、4~8 mm/击。对肯尼亚珊瑚礁灰岩地区钢管桩沉桩施工具有指导作用。

In view of the unreasonable standard of the original design of steel pipe piles in the coral reef limestone area of Kenya,we study the law of the new standard of the sinking of steel pipe piles,and obtain the recommended standard of the sinking steel pipe piles in the coral reef limestone area based on the theoretical calculation by Haili formula,the high-strain test,the static load test of anchor pile,and combining with the sinking construction of 1 440 steel pipe piles: 1) The final set shall be the main stopping criteria and design pile tip level as minor one in the coral reef limestone area in Kenya;2) 12 ~ 18,7 ~ 10 and 4 ~ 8 mm/blow can be the final set respectively for the φ1 200 mm×12 mm、φ1 200 mm×18 mm、φ1 200 mm×24 mm steel pipe piles with20 t-hammer and 1.2 m drop height.The study result may serve as a reference for the sinking construction of steel pipe piles in the coral reef limestone area in Kenya.