Evaluation, performance and design of concrete liquid containing structures

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Concrete liquid containing structures (CLCS) are extensively used for the storage of liquid and liquid-like materials including, water, oil, liquefied natural gas, chemical fluids, and wastes of different forms. Ground-supported tanks are more common in use because of their simplicity in design and construction. In addition they provide better resistance against hydrostatic and earthquake loading. These structures are considered as lifeline facilities, and their functional performance in terms of crack and leakage control is of significance. As numbers and sizes of storage tanks have increased over the years, so have their importance and the need to better understand their behavior under different loading conditions.**Canadian design standards do not directly address the structural design of CLCS and this has led to inconsistency in design of such facilities. Also, there is a great deal of inconsistency among the design standards for this important broad class of structures. This is mainly due to the lack of understanding of the behaviour of these structures under static and seismic loading. There is significant disagreement among design engineers on the validity of some of the provisions in codes and standards in this regard. One of the most controversial issue is related to the values used for the response modification factor (R) for different tank configurations and geometry such as for flexible and non-flexible base tanks under seismic loading. The R-values used to date are empirical in nature. The only way to rationalize these factors is by analytical and experimental testing.**The main objective of the proposed research study is to develop a rational design procedure, for concrete tanks that assures a safe leak resistant structure. The concept of water-tightness in liquid containing structures will be investigated. To investigate the seismic induced leakage problem, an experimental study will be conducted on specimens that are representative of full scaled base slab-wall connection portion of circular tanks with different connection details. These specimens while under reversed*cyclic loading will be simultaneously subjected to liquid pressure and leakage tests.*It is also intended to evaluate the performance of CLCS under temperature and shrinkage effect by installing instruments in actual CLCS while under construction. **The analytical study include evaluating the dynamic behavior of both rectangular and circular tanks using a rigorous finite element method capable of including the effect of fluid-structure-soil interaction as well as material non-linearities in a three dimensional domain. It is expected that this research program will provide a framework to understand the behavior of CLCS to meet safety, serviceability, construction, maintenance cost, and design standards. This framework will be useful towards the development of Canadian design guides for CLCS.**