矩形深基础地基极限承载力的理论解

发布时间：2018-01-18 03:07

本文关键词：矩形深基础地基极限承载力的理论解　出处：《岩石力学与工程学报》2014年S2期 　论文类型：期刊论文

【摘要】：现有深基础地基极限承载力理论一般仅适用于条形深基础,而实际工程中经常遇到的矩形深基础属于三维问题,对矩形深基础的极限承载力研究较少。根据刚塑性体的平衡条件,在分别考虑黏聚力和重度的情况下,推导方形深基础地基极限承载力的理论解,再结合条形深基础地基极限承载力的理论解,叠加后得到矩形深基础地基极限承载力的通用解析解。针对基础深度与宽度之比为2的情况,探讨在不同内摩擦角下承载力系数Nc,Nq与矩形深基础长宽比的变化关系以及在不同长宽比下系数Nc,Nq与内摩擦角的变化关系;针对基础长度与宽度之比为2情况,给出在不同内摩擦角下系数Nc,Nq与矩形深基础深宽比的变化规律。并与几种典型的深基础地基极限承载力半经验修正公式进行对比分析,结果表明承载力系数Nc,Nq的曲线变化趋势与现有半经验修正公式结果基本相同,但系数的具体数值有差异,表现为Nc的计算值与修正公式的结果相差不大,而Nq的计算值与修正公式的结果差别明显。由此,建议进一步研究现有深基础极限承载力的半经验修正公式。
[Abstract]:The existing ultimate bearing capacity theory of deep foundation is generally only applicable to strip deep foundation, but the rectangular deep foundation often encountered in practical engineering is a three-dimensional problem. According to the equilibrium condition of rigid plastic body, the theoretical solution of ultimate bearing capacity of square deep foundation is deduced under the condition of cohesion and gravity respectively. Combined with the theoretical solution of ultimate bearing capacity of strip deep foundation, the general analytical solution of ultimate bearing capacity of rectangular deep foundation is obtained after superposition, aiming at the case that the ratio of depth to width of foundation is 2. The relationship between the bearing capacity coefficient Ncnq and the aspect ratio of rectangular deep foundation under different angle of internal friction is discussed, and the relationship between the coefficient Ncnq and the angle of internal friction under different ratio of length to width is discussed. When the ratio of base length to width is 2, the coefficient NC is given under different internal friction angles. Compared with several typical semi-empirical formulas of ultimate bearing capacity of deep foundation, the results show that the bearing capacity coefficient NC. The variation trend of the curve of N _ Q is basically the same as the result of the existing semi-empirical correction formula, but the specific value of the coefficient is different, which shows that the calculated value of NC is not different from the result of the modified formula. However, the calculated value of N _ Q is obviously different from the result of the modified formula. Therefore, it is suggested that the existing semi-empirical correction formula for ultimate bearing capacity of deep foundation should be further studied.
【作者单位】：河海大学力学与材料学院;
【基金】：国家自然科学基金面上项目(51278169)
【分类号】：TU470
【正文快照】： 1引言针对条形深基础的极限承载力理论研究,W.F.Chen等[1-7]提出了相应的理论。实际工程中经常使用的矩形深基础属于三维问题,G.G.Meyerhof和G.C.Hu[3-4]针对矩形基础提出了修正公式,利用条形深基础的计算公式乘以某一形状修正系数的方法计算矩形深基础的极限承载力。而目前常

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