Blast Resistant Design for New Gas House

Blast Resistant Design for New Gas House

Our client produces a number of aerosol deodorant products, which use a Liquefied Petroleum Gas (LPG) propellant. LPG is a blend of butane and propane and as such is highly flammable and an explosion hazard. For this reason the automated aerosol canister filling operations are undertaken in mechanically ventilated gas houses external to the main manufacturing buildings. Our client is currently building a new facility, which requires a number of new gas houses.

MMI was appointed to prepare a blast-resistant design package for the proposed new gas houses. The client required a complete design and specification of this building within 4 weeks, which it could pass directly to its principal contractor on-site to start construction immediately

Our Approach

In order to meet the timescales and minimise construction costs, precast reinforced concrete wall panels were selected. These were treated as single-degree-of-freedom (SDOF) elements, based on a propped cantilever system, subjected to the provided pressure time history. Reinforcement checks were performed using Eurocode 2. Lifting sockets were specified to ease installation.

The foundations were designed using cast in-situ reinforced concrete to accept the wall panels within a trapezoidal slot. The global behaviour of the foundation was assessed and local demands were checked for the reactions from the wall panels.

The roof was designed as a steel frame constructed from universal beams sections supporting blast venting panels to limit the blast loads on the wall. The final design included specifications for the vent panels, blast doors and all associated fixings. 

The design accounted for symmetry to allow our client to produce an associated mirrored gas house from the same components, thus reducing fabrication costs.

MMI produced a full set of reinforcement and construction drawings for all components. These were delivered to the individual fabricators as necessary as well as the main contractor, who was then able to construct the design as per the intent. We supported the construction team by attending meetings and resolving problems with the various suppliers/fabricators.

Value Added

We supported our client with the design of a new gas house for normal and explosive loading conditions. The user requirements were considered and a simple and efficient solution was produced. The project was completed on time and within budget – preventing any operational delays.

For more information surrounding our Design & Assessment expertise, please contact us on 01925 230 655 (Warrington) or email us.