混凝土体积变形对拱筒叉缝的影响

Influence of Volume Change of Concrete on Forked Cracks in Tube-Shaped Archs

本文根据佛子岭连拱坝加强拱的拱冠拱端接触缝的实测资料,应用结构力学、夹层有限元、水工专业和数理统计等有关理论,研究分析了加强拱接触缝的实际工作状态.通过对水压、温度变形的计算,分析了混凝土体积变化对缝宽的影响,找出了在加强拱设置以后,拱筒叉缝继续向上发展的成因.分析表明:在连拱坝下游侧设置加强拱是阻止拱筒叉缝和缝端裂缝的有效措施,它消除了人们对悬臂三角体被顶出的疑虑.但应注意混凝土体积变形对缝的影响.

Based on the observed data of the contact cracks at the crown and abutment of the reinforcement and using the theories of structural mechanics , layer finite element , hydraulic structure and mathematical statistics , the actual working state of the contact cracks is studied. The influence of volume change of concrete on the width of the crack is analysed. Through the calculation of deformation of the old tube-shaped arch and reinforcement arch under the action of water pressure and temperature , and the cause is found out of the development of the forked cracks in the tube-shaped arch after the reinforcement arch is constructed. Analysis the construction of a downstream reinforcement arch shows that is an effective measures , which can prevent forked cracks from developing . It clears up the doubt that water pressure may push out the triangular body. However, attention should be paid to the influence of volume change of concrete on cracks.