后注浆超长钻孔灌注桩承载特性试验浅析  

Experimental analysis on bearing characteristics of super-long drilling hole pile with post-grouting

作　　者：陈翀[1] 詹少全[2] 樊荣霞 CHEN Chong;ZHAN Shaoquan;FAN Rongxia(Resource Survey and Evaluation Institute,Jiangsu Nonferrous Metals East China Geological Exploration Bureau,Nanjing 210007,Jiangsu,China;Geological Team No.814,Jiangsu Nonferrous Metals East China Geological Exploration Bureau,Zhenjiang 212005,Jiangsu,China;Survey and Design of Institute Co.,Ltd.,Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu,China)

机构地区：[1]江苏省有色金属华东地质勘查局资源调查与评价研究院,江苏南京210007 [2]江苏省有色金属华东地质勘查局八一四队,江苏镇江212005 [3]南京水科院勘测设计有限公司,江苏南京210029

出　　处：《矿产与地质》2021年第5期1013-1018,共6页Mineral Resources and Geology

摘　　要：通过对后注浆超长钻孔灌注桩的静载荷试验和桩身内力测试,研究了其承载及沉降等相关特性。经过分析表明,在高荷载作用下,后注浆超长桩表现出摩擦桩特性,桩顶沉降中超过90%是桩身压缩量导致,其摩阻力发挥程度与荷载大小、位置及土层类别均有关系,沉降桩径比(s/d)超过4%才逐渐发挥端部附近承载力,桩底沉渣会影响侧阻力和端阻力,桩端后注浆可消除沉渣影响,减小桩端沉降,提高承载力。因此基于以上承载特性,对于后注浆超长桩应用具有一定指导作用,根据桩端土层性状,充分利用后注浆优势,合理提高桩身弹性模量,适当降低桩长,发挥桩端土层阻力潜力。Through the static load test and the internal force test of the post-grouting super-long bored pile,its bearing and settlement characteristics are studied.The analysis shows that under high load,the post-grouting super-long pile exhibits the characteristics of friction piles.More than 90%of the pile top settlement is caused by the compression of the pile body.The degree of frictional resistance is related to the load size,location and soil type.All are related.The settlement pile diameter ratio(s/d)exceeds 4%before the bearing capacity near the end is gradually brought into play.The pile bottom sediment will affect the lateral resistance and the end resistance.Post-pile grouting can eliminate the influence of sediment and reduce the pile tip.Settlement,improve bearing capacity.Therefore,based on the above bearing characteristics,it has a certain guiding role for the application of post-grouting super-long piles.According to the properties of the pile end soil layer,make full use of the advantages of post-grouting,reasonably increase the elastic modulus of the pile body,appropriately reduce the length of the pile,and give full play to the soil at the end of the pile.Layer resistance potential.

关 键 词：超长桩 桩身压缩 后注浆 承载特性 

分 类 号：TU473.1[建筑科学—结构工程]