Response of reinforced concrete rectangular liquid containing structures under cyclic loading

The continual functioning of Liquid Containing Structures "LCS" is necessary for the well being of a society especially during and after an earthquake. One of the main parameters used in the seismic design of structures is the Response Modification Factor "R". For LCS, there has not been a justifiable guideline for determination of R factor and the empirical values have been implemented in the design of such structures. While the seismic design criteria for the buildings are mainly based on life safety and prevention of collapse, the concrete storage tanks should be designed to meet the serviceability limits such as leakage. This study was aimed at evaluation of the leakage behavior of ground supported open top rectangular RC tanks under the effect of cyclic loading. Full-scale specimens representing a cantilever wall were designed and built to simulate the leakage through the most critical region of the tank wall. A steel water pressure chamber was installed at the wall foundation connection to simulate the effect of the water pressure for the induced cracks at the critical location of the tank wall. Cyclic loading was applied on the top of the wall while the critical region of the wall was subjected to pressurized water. Different variables such as the thickness of the wall and the configuration of the shear key were examined. The effect of retrofitting the damaged specimen with Glass Fiber Reinforced Polymers (GFRP) sheets on the leakage behavior under cyclic loading was also investigated. Analytical studies using a Finite Element software were followed to assess the viability of the application of the FE analysis to the investigation of the cyclic behavior of the RC rectangular tanks. FE analysis results correlated well with the experimental observations. A study on the effect of R factor on the design loads was performed. Two major components of the R factor, namely, the ductility factor, and the overstrength factors were discussed and determined for the case of rectangular reinforced concrete LCS considering the leakage as the limit state. This study is limited to rectangular tanks in which the wall dimensions promote a one-way behavior.