How to Construct a Bund for Catastrophic Tank Failure
A bund construction must be designed and constructed to withstand the pressure exerted on it during a catastrophic tank failure this can be up to 6 times the bunds design capacity. Bunds are usually built on a concrete or reinforced masonry base but site-specific requirements may dictate alternative materials. Alternatively prefabricated bund walls fixed to an impermeable base are available and offer greater flexibility in terms of size and layout.
The material chosen to construct a bund must have adequate chemical resistance; if it does not the contaminant can attack the walls and floor leading to serious damage. The material should also be able to cope with any environmental conditions that are likely to affect it.
Understanding Bund Construction: Purpose and Importance
In some circumstances a bund constructed on soft ground will require soil improvement techniques to ensure stability; it can be useful to build the bund in layers and raise each fill phase to its final level, this helps to control the final slope of the bund. It is also recommended that there are leak tight expansion joints between different casts of bund wall and where there are penetrations in the walls for pipes.
An effective bund should be able to collect and contain not only the liquid it is designed to hold but also rainwater, unwanted material and debris; however the unwanted material must be removed regularly so that the bund does not fall below its capacity requirements. This is normally achieved by incorporating a drain at a low point in the bund floor, this should be connected to a manual valve which is kept closed.