三向变形条件下铜片止水破坏准则研究

Failure criterion of copper water-stops under three-dimensional deformation

铜片止水是水工混凝土结构分缝之间最重要的止水构件。混凝土结构在自重和水荷载作用下,常产生不均匀变形,使结构分缝之间的铜片止水产生拉伸(压缩)、沉陷和剪切三向变形(相对位移)。铜片止水的安全性取决于三向变形的量值,常通过三个方向的位移单独判断,未考虑三向位移的耦合作用。本文设计制作了两种尺寸共计40个铜片止水试件,通过三向加载独立控制的试验平台对铜片止水进行了不同拉伸、沉降位移的剪切试验,研究了铜片止水的剪切变形规律和破坏形态,得到了三维位移空间中的破坏包络面,提出了一个三向变位条件下铜片止水的变形破坏准则,可用于铜片止水的安全性判断。

Copper water-stop is the most important component for preventing water leak through the joints of hydraulic concrete structures.Concrete structures often experience uneven deformation under gravity and hydrostatic pressure,resulting in tension(or compression),settlement,and shear deformation(relative displacement)between the two wings of a copper water-stop.Its safety depends on the magnitude of the three-dimensional deformation,which is often judged by the displacement in each direction separately,without considering the coupling of different directions.This paper presents an experimental study of shear tests on copper water-stops under different tensile and settlement displacements,using a test stand that allows independent control of three directions and a total of 40 specimens in two different sizes are designed and fabricated.We examine shear deformation,its variations,and the failure modes of the specimens,and obtain a failure envelope surface in the three-dimensional displacement space.A failure criterion is derived for copper water-stops under three-dimensional displacement for judging the safety of similar water-stops.