中粗砂层桩端注浆工程实例及数值模拟研究  

Case Study and Numerical Simulation of Pile End Grouting in Medium-coarse Sand Layer

作　　者：李俊[1] 李粮纲[1] 丁耀胜 LI Jun;LI Lianggang;DING Yaosheng(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)工程学院

出　　处：《安全与环境工程》2019年第5期175-180,共6页Safety and Environmental Engineering

摘　　要：以潮汕地区的桩端注浆工程实例为依托,在分析工程地层特性及后注浆施工工艺的基础上,通过试桩静载试验,研究了在中粗砂层桩端注浆的作用效果,结合PFC2D数值模拟软件以颗粒流的形式从细观上对中粗砂层桩端注浆过程进行了数值模拟研究,并在细观上分析了中粗砂层桩端注浆的作用形式、作用机理。结果表明:在中粗砂层的桩端注浆能有效提升桩端砂层的强度,从而提高桩基的承载性能;桩端注浆会改变桩端土体的性质,引起注浆孔附近土体应力及孔隙率的变化;桩端的注浆形式也与注浆压力有关,当注浆压力较小时,桩端注浆主要以渗透注浆形式为主,当注浆压力增大达到一定程度时,桩端注浆会出现渗透、压密、劈裂并现的注浆形式。该研究可为在中粗砂层桩端注浆的设计和施工提供依据,并可为进一步完善注浆理论的研究且为类似工程优化注浆方案提供参考。Taking the pile end grouting project in Chaoshan area as an example,this paper analyses the stratum characteristics and post grouting construction technology of the project,and carries out the static load test of the pile to study the effect of pile end grouting in medium and coarse sand.Combined with PFC2Dnumerical simulation software in the form of particle flow,the paper carries out a numerical simulation study on the grouting process at the end of piles in medium-coarse sand layer,and analyses the action form and mechanism of grouting at the end of piles in medium-coarse sand layer in the form of micro-analysis.The results show that the pile end grouting in medium-coarse sand layer can effectively enhance the strength of the sand layer at the pile end,thereby improving the bearing capacity of the pile foundation.The grouting at the end of piles will change the properties of the soil at the end of piles and cause the changes of stress and porosity of the soil near the grouting holes;the grouting form at the end of piles is also related to the grouting pressure.When the grouting pressure is relatively small,the grouting at the end of piles is only in the form of permeability,and when the grouting pressure increases to a certain extent,the grouting at the end of the pile will take the form of seepage,compaction and splitting.This study can provide a basis for the design and construction of pile end grouting in medium and coarse sand layer,and can further improve the grouting theory research and provide a reference for similar projects to optimize grouting scheme.

关 键 词：中粗砂层 桩端注浆 注浆形式 颗粒流 

分 类 号：X948[环境科学与工程—安全科学] TU473.1[建筑科学—结构工程]