白鹤滩拱坝~#3底孔顺河向拉应力成因分析

Causes Analysis of Tensile Stress along River Direction in the No.3 Bottom Outlet of Baihetan Arch Dam

以白鹤滩拱坝#3底孔为例,先采用子模型法分析施工期工况下孔口的应力分布情况;再从荷载作用和结构形式角度对孔口顶、底板顺河向拉应力的产生原因进行了三维有限元分析;最后,采用复变函数理论求出孔口附近顺河向应力的解析解,分析其拉应力产生的原因。结果表明,泊松比效应是产生孔口顺河向拉应力的主要原因;上游悬臂结构是产生孔口顺河向拉应力的次要原因;弹性状态下配置钢筋对顺河向拉应力大小无明显影响。

Taking the No.3 bottom outlet of Baihetan Arch Dam as an example,sub-model method was used to analyze the orifice stress distribution at the construction condition.Then,from the aspects of load effects and structure forms,a comprehensive 3D finite element analysis was carried out on the causes of tensile stress along the river direction concentrated in the orifice top and bottom surface.Finally,the analytic solution of stress along the river direction was obtained by using complex function theory in elastic mechanics from the perspective of mechanical properties.The result shows that Poisson’s ratio effect is the primary factor leading to the orifice tensile stress along the river direction.The upstream cantilever structure is the secondary cause of the orifice tensile stress along the river direction.The reinforcement in elastic state has no obvious influence on the tensile stress along the river direction.