Full-Scale Experimental Determination of Concrete Pipe Joint Behavior and Its Modeling

As a consequence of unequal loading or variable soil conditions, longitudinal bending of buried gravity pipes leads to circumferential pipe cracking or joint opening, which results in groundwater infiltration or leakage. Since joints considerably affect longitudinal pipe behavior, an advanced investigation of this aspect requires knowledge of the joint mechanical properties and particularly of its stiffness. An experimental apparatus has been developed in order to determine the joint behavior under various loading conditions. Results of compression, shear, and bending tests are given in terms of force-displacement plots. A simple rheological bilinear model of the joint is elaborated from compression and shear tests and then validated on the experimental bending results. In general a good agreement is found between model and experimental output. This simple model will be implemented in numerical simulations of buried pipe behavior.