Abstract: 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.

Key words: copper water-stop, structural joint, failure criterion, concrete structure