DX嵌岩桩承载特性现场试验研究

发布时间：2018-01-14 09:15

本文关键词：DX嵌岩桩承载特性现场试验研究　出处：《地下空间与工程学报》2016年S2期 　论文类型：期刊论文

【摘要】：DX桩作为一种新型变截面桩,可有效提高单桩承载力、控制桩顶沉降,近年来得到广泛应用。本文介绍DX嵌岩桩首次代替直孔嵌岩桩的现场静载试验及工程应用研究。根据桩身钢筋应力计及桩底压力盒实测数据,对其荷载沉降特性及承载机理进行了分析。结果表明:(1)DX嵌岩桩Q-s曲线变化平稳,未呈现明显加速变形趋势;(2)承力盘位于强风化泥质粉砂岩表层或中层,盘阻力发挥较早,占总承载力比例达23.3%~31.6%,承载作用明显;此外,当侧阻力及盘阻力达到其承载极限时,端阻力能进一步发挥,占总承载力比例达26.2%~37.4%,桩身各部分能协调工作;(3)将该成果应用在广州太平洋广场及广西防城港钢铁项目中,采用Ф600 mm DX嵌岩桩代替Ф800 mm直孔桩,可提高单桩抗压承载力63%,减小嵌岩深度3~5 m,节约混凝土方量40%~50%,缩短施工时间40%以上,降低单桩造价31%~37%,经济效益十分显著。
[Abstract]:As a new type of variable section pile, DX pile can effectively improve the bearing capacity of single pile and control the settlement of pile top. In recent years, DX rock-socketed pile has been widely used. In this paper, the static load test and engineering application of DX rock-socketed pile in place of straight hole rock-socketed pile for the first time are introduced. According to the pile reinforcement stress meter and the measured data of pile bottom pressure box. The load-settlement characteristics and load-bearing mechanism of the pile are analyzed. The results show that the Q-s curve of the rock-socketed pile is stable and does not show a tendency to accelerate the deformation obviously. (2) the bearing plate is located in the surface or middle layer of the strongly weathered argillaceous siltstone, and the resistance of the plate plays an early role, accounting for 23.3g / 31.6% of the total bearing capacity, and the bearing capacity is obvious; In addition, when the side resistance and disc resistance reach their bearing limit, the end resistance can be further developed, accounting for 26.237. 4% of the total bearing capacity, the pile body parts can coordinate the work; This achievement is applied in Guangzhou Pacific Square and Fangchenggang Iron and Steel Project in Guangxi. The 600 mm DX rock-socketed pile is used to replace the 800 mm vertical hole pile in Guangzhou Pacific Square and Fangchenggang Iron and Steel Project in Guangxi. It can increase the bearing capacity of a single pile under compression by 63m, reduce the depth of rock socketed by 3m, save the quantity of concrete by 40m, shorten the construction time by more than 40%, and reduce the cost of single pile by 31g / 37%. The economic benefit is very remarkable.
【作者单位】：北京交通大学土木建筑工程学院;北京中阔地基基础技术有限公司;
【基金】：国家自然科学基金面上项目(51478035)
【分类号】：TU473.1
【正文快照】： 技术有限公司,北京100097)1引言DX桩作为一种新型变截面桩,能有效提高单桩及群桩承载力、控制桩顶沉降,近年来广泛应用在高层建筑、高速公路、铁路桥梁、中石油LNG储罐等基础工程中,总桩数达5万余根。该桩型在直桩的基础上,通过在中密~密实粘土层、砂层及卵砾石层旋挖挤扩,形

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