桩端后压浆技术在特大桥梁桩基中的试验与研究  

Test and research on pile-end post-grouting piles technology for super-large bridge pile foundations

作　　者：龚维明[1] 戴国亮[1] 张浩文[1] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2007年第6期1066-1070,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家科技支撑计划资助项目(2006BAG04B01)

摘　　要：介绍了桩端后压浆技术在特大吨位桥梁（苏通长江大桥、东海大桥、杭州湾跨海大桥、上海崇明越江通道）桩基中的应用情况．共21根对比试验桩，压浆桩的最大桩径为2．5～3．2m，最大桩长为125m，压浆后极限承载力高达上万吨．基于试桩的测试结果，对桩压浆前、后的承载力、位移变化情况以及承载特性作了分析．尽管后注浆工艺中压浆管的型式、压力、水泥浆用量、压浆持续时间等各不相同，桩尖处土层情况也不相同，但压浆后都不同程度地提高了桩基的极限承载力，但极限承载力的提高幅度有所不同．基于试验统计分析结果，给出了符合规定压浆条件的压浆后桩承载力的计算公式．研究成果可直接应用于大桥基础设计中．The application of pile-end post-grouting piles technology for super-large bridge piles is introduced, and there are totally 21 test piles for research which have been located in some important projects such as Sutong Yangtze River Bridge, Donghai Bridge, Hangzhou Bay Sea-Crossing Bridge, Shanghai Yangtze River Bridge of Shanghai-Chongming-Jiangsu channels etc. The maximum pile diameter varies from 2.5 meters to 3.2 meters, and the maximum length is 125 m. The bearing capacity of post-grouting piles is over ten thousands tons. Based on the test results, the improvement of the bearing capacity and displacement and the bearing characteristic before and after grouting are analyzed. The bearing capacity of piles are increased in some degree despite the differences in the patterns of grouting pipes, pressure, dosages of cement, grouting lasting time and so on. However, the increased values are very discrete. The calculation formula for the post-grouting piles in the prescriptive grouting condition is deduced based on the statistics analysis results of 57 test piles. The research results have been applied to the design of bridge foundation, which can exert the bearing potential and obtain notable economic benefit.

关 键 词：自平衡测试技术 桩端后压浆 承载力 压浆工艺 

分 类 号：TU473.16[建筑科学—结构工程]