利用丹麦公式确定锤击沉桩收锤标准的探讨  

Discussion on the Use of Danish Formula to Determine the Pile Driving Criteria

作　　者：辛建 XIN Jian(China Railway Design Group Co.Ltd.,Tianjin 300308)

机构地区：[1]中国铁路设计集团有限公司,天津300308

出　　处：《土工基础》2023年第1期92-93,98,共3页Soil Engineering and Foundation

摘　　要：预应力管桩采用锤击沉桩时收锤标准是重要的技术参数,施工过程中往往采用“标高控制为主,贯入度控制为辅”的收锤标准。由于对桩底标高和桩长过于重视,致使断桩、桩头破损等事故时有发生,给工程造成不必要的损失。结合某铁路工程,基于美标体系的锤击沉桩收锤标准的确定方法,利用丹麦(DANISH)公式,建立极限承载力与贯入度、锤击数的对应关系,按照最后一阵10击贯入度不大于计算值且最后一阵进尺25 cm所需要的锤击数不小于计算值作为主要的收锤标准,最终确定的收锤标准有效指导了实际工程施工。The driving criteria is an important parameter for the prestressed pipe pile installations.The common practice adopted in the construction was mainly with the emphasis on the pile tip elevation and aided by the penetration blow counts.Due to the excessive emphasis on the pile tip elevation control and the length of the pile,pile installation hazards such as broken piles and pile head damage occur frequently,which causing unnecessary extra cost to the construction.There is no clear statement in the relevant specifications for the determination of the hammer blow counts.This paper presents a case history of pile installation in a railway project using blow counts methods that are widely used in Europe and US.The Danish formula is used to establish the corresponding relationship among the ultimate bearing capacity,the penetration depth and the hammer blow counts.The penetrations is not greater than the anticipated value and the hammer blows counts required for last 25cm penetration is not less than the anticipated value as the main pile driving criteria.

关 键 词：预应力管桩 收锤标准 丹麦公式 

分 类 号：TU413[建筑科学—岩土工程]