Design of a flood proof storage tank

Abstract

Some storage tank terminals located in hurricane prone regions were heavily struck by hurricanes. An example is the storage tank terminal of Stolthaven Terminals (Stolt-Nielsen Limited) which is located in New-Orleans and was severely struck by Hurricane Katrina and Isaac. Damage to the terminal was caused by high wind pressures, but mainly due to flooding of the terminal caused by the overflowing levee. The storage tanks did not possess sufficient weight to counterbalance the buoyancy load generated by the flood. Due to this, storage tanks were lifted off their foundation and damage occurred to the bottom plate and the connections. Chemical liquid stored in the tank had now found its way into the environment. This disaster resulted in high costs and insurance claims from the contamination. The problem can be formulated as: "How can storage tank damage and chemical spill best be prevented during a flood?" Alternative solutions for a flood proof storage tank are presented which are applicable to the still-to-be-built new terminal next to the present terminal. Also a combination of the flood proof tank and management of tank operations is considered. 3 of the alternatives seem structurally feasible and are further elaborated in the report. These are: 1. The use of a steel-concrete-steel sandwich slab (SCS slab) inside the tank. This consists of 2 steel plates connected to a concrete core by means of shear studs. The slab should have sufficient weight to counteract the buoyancy load. [Tank alternative A] 2. Anchoring the area of the bottom plate of the tank to the concrete foundation by means of shear studs. [Tank alternative B] 3. Constructing a floating tank. This tank is provided with guiding piles, which allows the tank to go up and down, but keeps the tank at one location. [Tank alternative C] A simplified cost-benefit-analysis (CBA) is done to compare the alternatives to one of the basic solutions like the floodwall. The flood proof storage tank is compared to the basic solution (like the flood wall) a flexible alternative, because the tank does not need to be protected against floods.