后注浆超长灌注桩水平承载特性现场试验研究  

Experimental study on lateral bearing behavior of post-grouting super-long bored pile

作　　者：李洪江[1,2] 童立元[1,2] 刘松玉[1,2] 顾琴芬 朱炼 

机构地区：[1]东南大学岩土工程研究所,江苏南京210096 [2]东南大学江苏省城市地下工程与环境安全重点实验室,江苏南京210096 [3]江苏省建设工程设计施工图审核中心,江苏南京210036 [4]靖江市滨江新城投资开发有限公司,江苏靖江214500

出　　处：《建筑结构学报》2016年第6期204-211,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51279032);“十二五”国家科技支撑计划(2012BAJ01B02);江苏省建设系统科技计划项目(2014ZD66)

摘　　要：后注浆技术作为灌注桩补强技术,已在工程中得以应用,但有关后注浆桩体水平承载特性的研究较少。针对深厚土层中后注浆超长灌注桩的水平承载问题,结合工程实例,研究了后注浆单桩水平承载规律。通过现场水平静载试验,实测得到了试桩桩顶位移、转角、残余变形与水平荷载的关系,分析了后注浆桩身内力及桩侧土抗力分布特点,比较了有无后注浆情况下的单桩临界水平承载力大小。结果表明:已有规范方法可以对后注浆单桩临界水平承载力、极限水平承载力给出合理的判定,水平加载条件下后注浆桩侧土体抗力比例系数与桩顶位移呈非线性关系,桩侧桩端后注浆技术可显著提高灌注桩单桩临界水平承载力,较无后注浆桩体提高约20%。As a kind of pile foundation enhancement technology, the post-grouting bored pile has been used in many large projects, but there has been few research about its horizontal load-bearing characteristics. Based on the case of post-grouting super-long pile in deep soil layer under horizontal load, combined with the engineering example, its bearing rule was studied comprehensively and systematically. Through the horizontal static field loading test, the relationship between the horizontal force and displacement, rotation angle, residual deformation of pile top was obtained, and the pile body internal force and soil resistance distribution characteristics were analyzed. Comparison of the different critical bearing capacities of two cases whether using post-grouting technology or not was made. The results show that the standard method used to determine the test pile lateral critical bearing capacity and ultimate bearing capacity is reasonable and accurate. The relationship between displacement and horizontal resistanee ratio is nonlinear. Post-grouting technology can improve bored pile lateral critical bearing capacity by 20%.

关 键 词：灌注桩 后注浆 现场试验 水平承载力 土抗力 

分 类 号：TU473.14[建筑科学—结构工程] TU473.16[建筑科学—土工工程]