管桩土塞效应影响因素及承载性能试验研究  

Research on Influence Factors of Soil Plug Effect and Bearing Capacity of Pipe Pile

作　　者：张思峰 任国彰 刘乾 范伟 郑帅 ZHANG Si-feng;REN Guo-zhang;LIU Qian;FAN Wei;ZHENG Shuai(School of Traffic Engineering,Shandong Jianzhu University,Jinan 250101,China;Shandong Hi-Speed Maintenance Group Co.Ltd.,Jinan 250023,China;Shandong Luqiao Group Co.Ltd.,Jinan 250014,China)

机构地区：[1]山东建筑大学交通工程学院,济南市250101 [2]山东省高速养护集团有限公司,济南市250032 [3]山东省路桥集团有限公司,济南市250014

出　　处：《公路》2022年第10期75-82,共8页Highway

基　　金：山东省交通科技创新计划项目,项目编号2017B59;泉城产业领军人才支持计划项目。

摘　　要：预应力混凝土薄壁管桩(PTC管桩)施工时会产生土塞效应,从而对其施工难易程度及承载性能产生重要影响。基于开口管桩土塞效应及其承载机理,通过统计现场试验中PTC管桩总锤击次数、平均沉桩速率、土塞高度及沉桩深度等数据,并结合地基静力触探和管桩静载试验,建立了土塞率与上述各因素之间的关系。结果表明:随单桩总锤击次数增加,管桩土塞率呈减小趋势,且沉桩前期减小幅度较小、后期较大;随平均沉桩速率增大,土塞率呈增长趋势,且前期增长幅度较大而后期较小;土塞高度与土塞率呈线性正相关关系,土塞高度越大,土塞率越大,且不受桩机单击锤击能量的影响。静载和静力触探试验表明,桩顶累计沉降量和回弹量随土塞率的增加而增大,但桩端阻力是随土塞率减小而增大;土塞率越小,管桩承载性能越好,两者成负相关关系。研究成果可为类似公路地基处理工程施工提供借鉴。The construction of prestressed concrete thin wall pipe pile(PTC pipe pile)will produce soil plug effect,which will have an important influence on its construction difficulty and bearing capacity.In this paper,based on the soil plug effect of open pipe pile and its bearing mechanism,the relationship between soil plug rate and the above factors is established by statistical data of PTC pipe pile in field tests,such as total hammer number,average pile sinking rate,soil plug height and pile sinking depth,combined with the static penetration test of foundation and static load test of pipe pile.The result shows that the soil blockage rate of pipe pile decreases with the increase of the total hammering times of single pile,and the decrease is small in the early stage and large in the later stage.With the increase of average pile driving rate,the soil plug rate increases,and the increase rate is large in the early stage,but small in the late stage.There is a positive linear correlation between the soil plug height and the soil plug rate.The higher the soil plug height is,the higher the soil plug rate is,and it is not affected by the hammer energy of pile machine.The static and static penetration tests show that the accumulated settlement and resilience of pile tip increase with the increase of soil plug rate,and the smaller the soil plug rate is,the better the bearing capacity of pipe pile is.The research results can provide reference for similar highway foundation treatment engineering construction.

关 键 词：管桩 现场试验 土塞效应 影响因素 承载性能 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU473.13[建筑科学—结构工程]