黄土中圆形抗拔锚板基础承载力分析

Analysis of the pullout uplift bearing capacity of circular anchor plates in loess

摘要:

在三维状态下运用极限平衡理论，对黄土中圆形抗拔锚板基础在受到垂直于板面荷载作用下的承载力进行理论分析，该理论研究考虑了锚板在上拔过程中板周土体的破裂方程、破裂面上的正应力和剪应力、埋深率等影响因素。理论公式计算结果表明：抗拔锚板承载力系数随着锚板埋深的增加而增大，并且当深度达到一定值时，承载力系数将达到其极限值；当埋深率h/D=1~2之间时，上覆土重对承载力系数影响较小；当h/D=4时，土体和锚板之间的吸力对承载力系数的影响大于锚板上覆土重；当h/D>4时，上覆土重对锚板抗拔承载力起着决定作用。理论计算公式与已有学者的试验结果进行对比表明提出的模型理论计算结果和其他学者的试验结果有良好的一致性，验证了该理论的正确性，为工程中抗拔锚板的设计提供了有价值的参考。

关键词:黄土;圆形抗拔锚板;承载力;破裂面;破裂方程;埋深率

Abstract:

Based on limit equilibrium theory in three-dimension, the pullout uplift bearing capacity of circular anchor plates in loess under the loading which is vertical to the plate surface is studied. The study considers the equation of loess failure around anchor plates, normal stress and shear stress on the failure plane and buried depth rate h/D when the plates are being uplifted. It is found that the pullout uplift bearing capacity increases with the buried depth, and will reach the limit when the buried depth reaches a certain value. When h/D=1 to 2, the overlying soil weight puts slight effect on pullout uplift bearing capacity; when h/D=4, suction between the soil and the anchor plate contributes more than the overlying soil weight to the results; what is more, in the case of h/D>4, the overlying soil weight plays a decisive role in the pullout uplift bearing capacity. The comparison between the theoretical calculation and the test results of other researchers demonstrates that the theoretical results show consistency with the test results; thus verifying the correctness of the theory. It provides a valuable reference for the design of pullout uplift anchor plates.

Key words:loess; pullout uplift circular anchor plate; bearing capacity; failure plane; failure equation; buried depth rate