溜桩后桩基承载力的评估  

Evaluation of pile foundation capacity after pile sliding

作　　者：许文兵 刘奎 李飒[2] 孙红军 李利飞 王亮 孙振平 

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200030 [2]天津大学建筑工程学院,天津300072

出　　处：《水利水运工程学报》2016年第4期70-75,共6页Hydro-Science and Engineering

基　　金：国家重点基础研究发展计划(973计划)资助项目(2014CB046800);国家科技重大专项(20112X05056-002-01);上海交通大学国家重点实验室开放课题(1201)

摘　　要：打桩过程中溜桩容易引发安全事故。溜桩的产生,往往造成打桩锤击数的预测值与实测值之间偏差较大,此时准确评价溜桩后桩基承载力就成为实际工程中非常关注的问题。以某工程实例为基础,根据现场高应变动测试验和打桩记录,研究了溜桩对桩基的影响。打桩记录显示,溜桩的产生会导致打桩总能量的降低;现场动测试验结果表明,溜桩导致打桩结束时的承载力明显减小。采用现有对打入桩进行桩基承载力评估方法得到的结果无法满足设计要求。为此,在评估打入桩最终承载力时将桩基分为溜桩段和非溜桩段,对不同区域采用不同方法进行承载力评估,所得结果满足设计要求。The pile sliding during pile installation may cause serious accidents, such as the pile falling out of thedrive cap , or pile damaged by high tension stresses. At the same tim e, the pile sliding often makes a remarkabledeviation between the drivability prediction and the measured blowcounts. Therefore, the pile foundation capacityafter the pile sliding is a good problem for engineers to pay more attention to in practical works. In this paper, acase history is studied based on analysis results of dynamic load tests and pile driving records, and the influences ofthe pile sliding on the pile foundation capacity is analyzed. The analysis results show that the pile sliding will makea total energy released by pile driving decrease significantly. The analysis results from CAP WAP show that thedecrease of the pile foundation capacity at the end of the pile driving is also very obvious. The pile foundationcapacity evaluated by the method and often used today can not satisfy the design requirements. The new method isapplied considering the effects of the pile sliding during the pile driving. The pile foundation capacity after the pilesliding can be calculated with different methods in different areas, and the area is divided based on a place wherethe pile sliding happens. The analysis results are used in the works, and it is found that the results are in a goodagreement with the behaviors of pile in engineering practice.

关 键 词：溜桩 打桩记录 动测试验 桩基承载力 

分 类 号：TU473.11[建筑科学—结构工程]