超薄型PCC桩在滩涂超软土地基处理工程中的实践  

Application of ultra-thin PCC pile in tidal ultra-soft soil foundation treatment project

作　　者：李伟 隋欣 李卫国 金小荣 莫立成 朱建才 LI Wei;SUI Xin;LI Weiguo;JIN Xiaorong;MO Licheng;ZHU Jiancai(Fangyuan Construction Group Co.,Ltd.,Taizhou 317700,Zhejiang,China;The Architectural Design&Research Institute of Zhejiang University Co.,Ltd.,Hangzhou 310000,Zhejiang,China;Taizhou Social Development Engineering Management Co.,Ltd.,Taizhou 318000,Zhejiang,China)

机构地区：[1]方远建设集团股份有限公司,浙江台州317700 [2]浙江大学建筑设计研究院有限公司,浙江杭州310000 [3]台州市社会发展工程管理有限公司,浙江台州318000

出　　处：《地基处理》2024年第6期618-625,共8页Journal of Ground Improvement

摘　　要：以地基承载力约为50 kPa的台州集聚区某学校项目为工程背景,使用壁厚仅为80 mm的超薄型PCC桩在超软土中进行地基加固。通过对超薄型PCC桩进行单桩竖向静载试验和单桩复合地基静载试验,并结合现场开挖情况与实测数据研究其在滩涂超软土地基中的加固效果。试验结果表明,超薄型PCC桩在滩涂超软土中具有成桩质量可靠、单桩承载力高、施工速度快、节约混凝土用量的优点。超薄型PCC桩复合地基承载力与沉降均可满足地基加固要求,具有经济优越性。基于现场试验数据,利用ABAQUS对超薄型PCC桩进行三维有限元数值模拟,揭示了摩阻力分布等无法通过静载试验得到的结果。在竖向荷载作用下,超薄型PCC桩的上部与下部侧摩阻力异步发挥,沉降初始阶段超薄型PCC桩的上部侧摩阻力发挥,随后桩下部的侧摩阻力以及桩端阻力相继发挥,且桩侧摩阻力先于桩端阻力达到极限状态;桩顶荷载主要由桩侧摩阻力承担。Based on a school project in Taizhou with a foundation bearing capacity of 50 kPa,the ultra-thin PCC pile with a wall thickness of only 80 mm was used for foundation reinforcement in ultra-soft soil.The static load test of single pile and the static load test of single pile composite foundation were carried out on the ultra-thin PCC pile,and the reinforcement effect on the tidal ultra-soft soil foundation was studied by combining the field excavation conditions with measured data.The test results show that ultra-thin PCC pile has advantages of reliable pile formation quality,high bearing capacity,fast construction speed and saving concrete consumption in tidal ultra-soft soil.The bearing capacity and settlement of ultra-thin PCC pile composite foundation can meet the requirements of foundation reinforcement and it is more economical.Based on the field test data,ABAQUS was used to perform 3D finite element numerical simulation of ultra-thin PCC pile,revealing results such as friction resistance distribution which cannot be obtained by static load test.Under vertical load,the upper and lower lateral frictional resistance of ultra-thin PCC piles are asynchronously exerted.At the initial stage of settlement,the lateral friction resistance of the upper part of ultra-thin PCC pile plays an effective role,and then the lateral friction resistance of the lower part of the pile and the tip resistance play an effective role successively.The pile side friction resistance reaches the limit state earlier than the pile tip does.The pile top load is mainly borne by pile side friction.

关 键 词：超薄型PCC桩 超软土 地基处理 ABAQUS 复合地基承载力 

分 类 号：TU473[建筑科学—结构工程]