刍议相关规范中关于单桩承载力计算的几点疑惑

发布时间：2018-03-16 13:26

本文选题：单桩承载力　切入点：特征值　出处：《岩土力学》2015年10期 　论文类型：期刊论文

【摘要】：国内相关规范中单桩抗压承载力设计计算方法分为特征值法及极限值法两类,单桩承载力均通过桩侧阻力与桩端阻力直接相加的方法得到,在概念及理论上均存在着不完善之处,主要原因是桩侧阻力与桩端阻力的力学特性及对变形的要求不同、不能同步发挥所致。相对来说,极限值设计法更直接、更可靠、更准确,概念更明确,且易于与国际接轨,建议规范优先采用。不同规范根据抗拔试验结果求取单桩抗拔承载力的计算方法存在矛盾,建议求取时桩的自重按天然重度计算、不考虑水的浮力。建议相关规范对以下两种现象进行深入研究:桩长超过有效长度后,单位长度侧摩阻力将会降低;部分工程中得到的抗拔桩的抗拔系数远小于相关规范推荐值,尤其是桩长较长时。
[Abstract]:The design and calculation methods of compressive bearing capacity of single pile in relevant codes in China are divided into two categories: eigenvalue method and limit value method. The bearing capacity of single pile is obtained by adding the pile side resistance and pile tip resistance directly. There are some imperfections in concept and theory. The main reason is that the mechanical characteristics and deformation requirements of pile side resistance and pile tip resistance are different, which can not be brought into play simultaneously. In contrast, the limit value design method is more direct and reliable. More accurate, clearer concept, and easy to connect with the international standards, it is suggested that the code should be adopted first. There are contradictions in the calculation methods of the uplift bearing capacity of single pile according to the results of the uplift test, and it is suggested that the weight of the pile should be calculated according to the natural weight when it is taken. Considering the buoyancy of water, it is suggested that the following two phenomena should be deeply studied in the relevant codes: when the pile length exceeds the effective length, the side friction of the unit length will be reduced; The uplift coefficient of the uplift piles obtained in some projects is far less than the recommended values of the relevant codes, especially when the pile length is longer.
【作者单位】：中国京冶工程技术有限公司;
【分类号】：TU473.1

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