（1 清远市建设工程综合服务站， 清远 511500； 2 广东省建设工程质量安全检测总站有限公司， 广州 510075；3 广东省基础工程集团有限公司， 广州 510620； 4 广东建设职业技术学院土木工程系， 广州 510450）

［摘要］为了解决在建结构主体中因引孔静压成桩后引孔深度大于管桩桩底深度形成桩底脱空问题，在比选工程中常见桩基加固方法（注浆、锚杆静压钢管桩、微型灌注桩、微型钢管桩）的基础上，采用了微型钢管桩预应力封桩加固技术方案，同时对该加固方案进行了设计，并介绍了其施工工艺。最后，对加固后本工程的单桩进行竖向抗压静载试验和建筑变形监测。结果表明，加固桩极限承载力Qu≥1 300kN，满足钢管桩设计承载力650kN要求，监测的沉降变形比较稳定，趋于收敛。

［关键词］桩基加固；微型钢管桩；预应力封桩；引孔静压桩

中图分类号：TU354文献标识码：A文章编号：1002-848X(2021)08-0115-04

Technical scheme and application of pile foundation reinforcement for a high-rise building under construction

LI Shan1, WANG Kai2, SHAO Mengxin3, ZENG Xin4

(1 Qingyuan Combined Services Station of Building Construction, Qingyuan 511500, China; 2 Guangdong Construction Engineering Quality and Safety Inspection Station Co., Ltd., Guangzhou 510075, China; 3 Guangdong Foundation Engineering Group Co., Ltd., Guangzhou 510620, China; 4 Department of Civil Engineering, Guangdong Construction Polytechnic, Guangzhou 510450, China)

Abstract:In order to solve the problem of void at the bottom of the pile caused by reason that the depth of leading hole is greater than the depth of pipe pile bottom after jacked pile for pre-bored hole in the main structure under construction, the reinforcement technology of micro-steel-piles of sealed piles with prestress was adopted based on the comparison of the common pile foundation reinforcement methods in engineering (grouting, anchor rod static pressure steel pipe pile, micro cast-in-place pile, micro steel pipe pile). At the same time, the reinforcement scheme was designed and its construction technology was introduced. Finally, vertical compression static test and building deformation monitoring on the single pile of the project after reinforcement were caried out. The results show that the ultimate bearing capacity of the reinforced pile Qu ≥1 300kN, which meets 650kN of the design bearing capacity of steel pipe pile, the settlement deformation monitored is stable and tends to converge.

Keywords:pile foundation reinforcement;micro steelpipe pile;sealed pile with prestress;jacked pile for pre-bored hole

作者简介：李善，硕士，工程师，注册土木工程师（岩土），Email:729730018@qq.com。