武汉沿江地区超长灌注桩承载性状试验研究  

Experimental study on bearing behavior of super-long bored piles in the riverside area of Yangtze River in Wuhan

作　　者：王金玺 唐红[1] 许将 WANG Jinxi;TANG Hong;XU Jiang(College of Urban Construction,Wuhan University of Science and Technology,Wuhan 430081,China;Wuhan Surveying-Geotechnical Research Institute Co.,Ltd.,MCC,Wuhan 430080,China)

机构地区：[1]武汉科技大学城市建设学院,湖北武汉430081 [2]中冶集团武汉勘察研究院有限公司,湖北武汉430080

出　　处：《武汉大学学报（工学版）》2024年第2期178-186,共9页Engineering Journal of Wuhan University

摘　　要：为研究武汉沿江地区大直径超长灌注桩的承载变形特性,结合武汉“长江之门”大厦现场静载荷试验,对该项目3根桩径为1200 mm、桩长为57.5 m的钻孔灌注桩试验数据进行了分析。结果表明:3根桩的荷载-沉降(Q-s)曲线均为陡降型,极限承载力为40000 kN,桩顶沉降主要由桩身压缩(占比在90%以上)产生;在砂土层中,桩侧注浆减小了极限侧摩阻力发挥所需的桩土相对位移;在岩层中,微小的相对位移量即会使桩侧摩阻力达到极限值;试桩的桩端阻力与桩端位移关系曲线表现为加工硬化的双折线模型,在极限荷载作用下试桩表现为摩擦型桩特性;桩端阻力并未充分发挥,在承载力计算时桩端阻力应乘以相应的系数。试验结果为本项目工程桩设计提供资料的同时,也可为该地区类似桩基工程提供理论和实践参考。In order to study the load-bearing deformation characteristics of large-diameter and super-long bored piles in the riverside area of Yangtze River in Wuhan,the test data of three bored piles with pile diameter of 1200 mm and pile length of 57.5 m were analyzed in combination with the static load test of Wuhan Yangtze River Gate Building construction site.The results show that the load-settlement curves of the three piles are of steep descent type,the ultimate bearing capacity is 40000 kN,and the settlement of the top of the pile is mainly caused by the compression of the pile body,accounting for more than 90%.In the sand soil layer,the pile side grouting reduces the relative displacement of the pile and soil required for the exertion of the ultimate side friction resistance.In the rock formation,the pile side friction reaches the limit value with a small relative displacement.The relationship curve between resistance and displacement of the test pile tip is shown as a double fold line model with pressure hardening.Under the ultimate load,the test piles are characterized as friction piles.The resistance at the end of the test pile is not fully developed,and the resistance at the end of the pile should be multiplied by the corresponding coefficient when calculating the bearing capacity.The test results can provide information for the project pile design,and also provide theoretical and practical reference for similar pile foundation projects in this area.

关 键 词：超长灌注桩 极限承载力 侧摩阻力 桩土相对位移 桩端阻力 

分 类 号：TU473.1[建筑科学—结构工程]