海洋工程中大直径超长桩极端贯入特性研究  

Study on extreme penetration characteristics of large-diameter and super-long piles in ocean engineering

作　　者：闫澍旺[1,2] 贺小青[1,2] 贾沼霖 陈国锋[1,2] 赵亮[1,2] Yan Shuwang He Xiaoqing Jia Zhaolin Chen Guofeng Zhao Liang(State Key Laboratory of Hydraulic Engineering Simulation and Safety in Tianjin University, Tianjin 300072, China Institute of Geotechnical Engineering, Tianjin University, Tianfin 300072, China Huadian Heavy Industries Co. , Ltd, Tianjin 300010, China)

机构地区：[1]水利工程仿真与安全国家重点实验室,天津大学,天津300072 [2]天津大学岩土工程研究所,天津300072 [3]华电重工股份有限公司博士后科研工作站,天津300010

出　　处：《工程勘察》2017年第2期1-9,共9页Geotechnical Investigation & Surveying

基　　金：国家自然科学基金资助项目(51279127);国家自然科学基金(41372291);国家自然科学基金优秀青年基金(51322904)

摘　　要：海洋石油平台大直径超长桩贯入过程中会出现两种极端现象,即拒锤与溜桩。本文总结了打桩过程中不同型式桩的贯入特性,针对出现拒锤和溜桩现象的基桩的可打入性特性进行分析研究,提出以下措施:对于基桩连续贯入条件下的模拟计算,提出连续可打入性分析的重点是砂土和粘性土的不同疲劳效应;针对拒锤现象,结合实际工程对拒锤发生机理进行了研究,根据海上高应变复打试验得到桩周土强度随时间变化的规律公式,提出Restart的计算模拟方法;针对溜桩现象,结合实际工程对溜桩的过程和发生机理进行了探讨,提出了在溜桩状态下土阻力的计算方法,在此基础上,建立了判断溜桩范围的分析计算方法;利用CAPWAP软件针对海洋平台桩基工程沉桩过程中的极端现象进行了分析计算,验证了所提出的方法的合理性,可供桩基设计以及沉桩施工参考。During the penetration of large diameter and super-long piles for offshore oil platform,it is likely to encounter the two extreme cases,repelling hammering and pile run.The penetrating characteristics of different types of piles are summarized,and the characteristics of the pile drivability are studied under the conditions of repelling hammering and pile run.Some measures are presented that for the simulation under the condition of continuous penetration of pile,and the key point of the analysis of continuity is the different fatigue effects of sand and clay.For repelling hammering phenomenon,the mechanism of repelling hammering is studied by combining the practical engineering and the regular formula of the strength-time relation of the soil around the piles is obtained in offshore high-strain recovery test,and a simulation method of Restart is proposed.As for the pile-run case,the process and mechanism of pile run are discussed in combination with the practical engineering and the calculation method of soil resistance under the condition of pile run is presented.The analysis and calculation method to predict the range of the pile run is established.The extreme cases in the process of pile sinking for offshore platformare analyzed by using CAPWAP software,and the rationality of the proposed method is verified and it could be used in the design and construction of pile foundation.

关 键 词：大直径 超长桩 桩 拒锤 溜桩 

分 类 号：TU473.1[建筑科学—结构工程]