What factors may contribute to excessive deflection in tanks made of fiberglass reinforced plastic?

Excessive deflection in fiberglass reinforced plastic (FRP) tanks can indeed result from improper bedding and poor compaction. When these tanks are not adequately supported by the surrounding soil or foundation, stresses can accumulate in the structure, leading to deformation. Proper bedding ensures that the tank has a uniform support base, which is crucial for distributing loads evenly. If the bedding is insufficient or the soil is not well-compacted, certain areas of the tank may experience higher loads than others, causing it to deform excessively over time.

This issue can be particularly pronounced in fiberglass tanks because they are more flexible than steel and may not withstand uneven pressures without experiencing significant deflection. Such excessive deflection can affect the tank’s integrity, leading to potential leaks or failure, which is a critical concern in the management of underground storage tanks.