四边固支板在均布荷载作用下的剪力分布规律

Shear force distribution pattern of four-side fixed support plates under uniform loads

沉箱底板抗剪往往需要控制底板厚度,而现有剪力分布规律研究较少,针对此问题采用有限元方法进行不同组合工况的计算,研究四边固支板在均布荷载作用下,板边最大剪力分布以及最大剪力随板厚、边长、长宽比的变化关系,得出最大剪力与平均剪力之比的一般规律。研究结果表明:板边剪力分布呈类抛物线形,板边最大剪力值小于弹性薄板理论计算的最大剪力值;相同尺度和荷载情况下,矩形板厚度增大其板边最大剪力值将有所减小;矩形板尺度增大,板边最大剪力值将迅速增大且最大剪力与平均剪力之比也有所增大;对于常用沉箱纵横隔墙间距和底板厚度,板边最大剪力与平均剪力之比通常为1.3~1.6。总结剪力分布与仓格尺度的关系,旨在为类似工程设计提供参考。

The shear resistance of the bottom plate of a caisson often controlls the thickness of the bottom plate,and there is limited research on the distribution law of shear force.To address this issue,finite element method is used to calculate different combinations of working conditions.The maximum shear force distribution at the edges of plates with four-side fixed under uniform load,and the relationship between the maximum shear force and the thickness,length and aspect ratio of the plate are studied.The general rule of the ratio of maximum shear force to average shear force is obtained.The results show that the distribution of shear force at the edge of the plate follows a parabolic shape.The maximum shear force at the edge of the plate is less than the maximum shear force calculated by the elastic thin plate theory.Under the same scale and load conditions,the maximum shear force at the edge of the plate will decrease as the thickness of the rectangular plate increases.As the size of the rectangular plate increases,the maximum shear force at the edge of the plate will rapidly increase,and the ratio of the maximum shear force to the average shear force will also increase.For commonly used caissons longitudinal and transverse partition wall spacing and bottom plate thickness,the ratio of the maximum shear force at the edge of the plate to the average shear force is usually 1.3 to 1.6.This paper summarizes the relationship between shear force distribution and grid scale,aiming to provide reference for similar engineering designs.