饱和土中后注浆灌注桩的注浆压力回归分析及优化  

Regression analysis and optimization for grouting pressure of post-grouting pile in saturated soil

作　　者：胡涛[1,2] 万志辉[1,2] 戴国亮[1,2] 龚维明[1,2] 朱铮[1,2] Hu Tao;Wan Zhihui;Dai Guoliang;Gong Weiming;Zhu Zheng(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education,Southeast University,Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京211189 [2]东南大学土木工程学院,南京211189

出　　处：《东南大学学报（自然科学版）》2022年第5期875-882,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51878160,52008100);江苏省基础研究计划(自然科学基金)资助项目(BK20200400)。

摘　　要：为解决现有规范中注浆压力计算公式在黄河流域下游地区适用性差的问题,采用数理统计方法建立了适用于该地区的注浆压力计算公式.基于莫尔-库伦强度理论及土体极限平衡条件,对现行规范中注浆压力计算公式进行优化.采用回归分析方法,得到注浆阻力经验系数和黏聚力修正系数的取值范围.通过现场试验对所提公式和现行规范公式进行对比分析.结果表明,相较于采用现行规范公式进行后注浆作业的试桩,采用所提公式进行后注浆作业的试桩承载力响应速度更快,桩顶沉降控制能力更好.在黄河流域下游地区使用所提公式进行后注浆可以有效改善灌注桩的承载特性.The grouting pressure calculation formula suitable for the downstream area of the Yellow River Basin was established by using the mathematical analysis method to solve the problem of poor applicability of the grouting pressure calculation formula in current codes. Based on the Mohr-Coulomb strength theory and the soil limit equilibrium condition, a calculation formula for grouting pressure in the current code was optimized. The range of the empirical coefficients of the grouting resistance and the correction coefficients of cohesion were proposed by the regression analysis method. Field loading tests were used to compare the proposed formula and the current code formula. The results show that the test pile using the proposed post-grouting operation formula responds to changes in bearing capacity more quickly and has better control over pile top settlement than the test pile using the current code formula. In the lower reaches of the Yellow River basin, using the proposed formula for post-grouting can effectively improve the bearing characteristics of bored piles.

关 键 词：钻孔灌注桩 组合后注浆 注浆压力 桩基承载力 饱和土 

分 类 号：TU473[建筑科学—结构工程]