较破碎岩石地基中嵌岩桩竖向承载力分析  

Analysis on vertical bearing capacity of rock-socketed pile in relatively broken rock foundation

作　　者：王金玺 唐红[1] 许将 高一帆 Wang Jinxi;Tang Hong;Xu Jiang;Gao Yifan(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,武汉430081 [2]中冶集团武汉勘察研究院有限公司,武汉430080

出　　处：《工程勘察》2023年第2期31-37,共7页Geotechnical Investigation & Surveying

摘　　要：嵌岩桩的分析基于桩端置于完整岩体中的研究较多,而本文更偏向于较破碎岩体中的桩的竖向承载力分析。结合武汉某高层项目现场静载荷试验,对较破碎岩体中的嵌岩桩承载力进行分析,研讨此类岩体中桩基的承载性状。结果表明:较破碎岩石中嵌岩桩的Q-s曲线呈陡降型,桩顶沉降主要由桩身压缩引起,达到了90%以上;在有效桩长范围内,桩身轴力随埋深增加呈递减趋势;侧摩阻力分布曲线呈“上小下大”,其发挥具有异步性;极限荷载下,试桩端阻比平均值为30.59%,呈端承摩擦型桩特性。此外,通过对嵌岩段承载力进行修正,提出了较破碎岩体中嵌岩桩的承载力计算方法,并通过实例验证的结果与实测值相差较小。试验成果可为较破碎岩体中桩基设计提供借鉴。The analysis of rock-socketed piles is based on the study of pile ends placed in intact rock masses,while this paper is more inclined to the analysis of vertical bearing capacity of piles in relatively broken rock masses.The bearing capacity of rock-socketed piles in the relatively broken rocks is analyzed by combining the static load tests for a high-rise project in Wuhan,and the bearing properties of the pile foundation in such rocks are discussed.The results show that the Q-s curves of the embedded piles in the relatively broken rock is steeply descending,and the settlement of pile top is mainly caused by the pile compression,which reaches more than 90%;within the effective pile length,the pile axial force is decreasing with the increase of burial depth;the distribution curve of lateral friction resistance is the type with"small up and large down",and its play has asynchronous;under the ultimate load,the average value of end resistance ratio is 30.59%,showing the characteristics of end-bearing friction pile.In addition,by correcting the load bearing of the embedded section,the method for calculating the load bearing capacity of rock-socketed pile in relatively broken rock is proposed,and the results are verified by the example with the less difference from the measured values.The test results could provide the reference for the design of pile foundation in the relatively broken rock.

关 键 词：较破碎岩体 嵌岩桩 静载试验 单桩竖向极限承载力 

分 类 号：TU473.1[建筑科学—结构工程]