粉质黏土地层桩侧劈裂注浆参数设计与效果评价  

Parameter design and effect evaluation of pile side splitting grouting insilty clay stratum

作　　者：王钰鑫 吕思忠 姚望 林春金[1] 张明 李召峰[1] 张健[1] 王衍升 Yuxin WANG;Sizhong LÜ;Wang YAO;Chunjin LIN;Ming ZHANG;Zhaofeng LI;Jian ZHANG;Yansheng WANG(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,Shandong,China;Shangdong Hi-speed Company Limited,Jinan 250014,Shandong,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]山东高速股份有限公司,山东济南250014

出　　处：《山东大学学报（工学版）》2023年第6期70-81,共12页Journal of Shandong University（Engineering Science）

基　　金：国家自然科学基金面上项目(52178338);山东省自然科学基金重点项目(ZR2020KE006);山东省重点研发计划(重大科技创新工程)项目(2021CXGC010301)。

摘　　要：针对粉质黏土地层在役桩基础承载力不足问题,采用数值模拟和现场试验相结合的方法实现在役桩基注浆加固参数设计与加固效果评价。通过浆脉施加体积应变的方法建立注浆压力传递有限元模型,研究不同注浆工况下粉质黏土地层桩侧径向压力的分布规律,提出注浆参数设计方法。土压力随距离的衰减是非线性的,在一定的土体参数下注浆压力为2.0 MPa,注浆孔与桩侧距离为0.5 m时,传递到桩侧的径向压力较大。以京台高速改扩建现场桩基为模型,绘制不同工况下桩基承载力提升幅度等值线图,注浆加固后桩基承载力提高了30.3%~89.4%,为在役桩基加固效果提供参考。Aiming at the problem of insufficient bearing capacity of in-service pile foundation in silty clay stratum,numerical simulation and field test were used to realize the parameter design and reinforcement effect evaluation of in-service pile foundation grouting.The expanding form of split grouting vein was analyzed,the finite element model of grouting pressure transmission was established by applying volume strain to the vein,the distribution law of radial pressure on the pile side in silty clay stratum under different grouting conditions was studied,and the design method of grouting parameters was put forward.The attenuation of earth pressure with distance was nonlinear.Under certain soil parameters,when the grouting pressure was 2.0 MPa and the distance between grouting hole and pile side was O.5 m,the radial pressure transmitted to pile side was larger.At the same time,taking the pile foundation in the reconstruction and expansion site of Beijing-Taibei Expressway as a model,the contour map of the increase range of pile foundation bearing capacity under different working conditions was drawn,and the pile foundation bearing capacity was increased by 30.3%-89.4%after grouting reinforcement,which provided reference for the reinforcement effect of in-service pile foundations.

关 键 词：粉质黏土 桩侧注浆 桩基承载力 数值模拟 加固效果评价 

分 类 号：TU43[建筑科学—岩土工程]