Abstract:
Liquid storage tanks are usually located in nearshore or coastal regions with soil profiles containing thick layers of compressible soils. These storage tanks are usually of large diameter up to 90m and carry high loads, and the tanks are supported by heavy foundations such as piles. These structures are subjected to huge lateral loads due to wind and earthquake, and any damage to storage tanks with highly inflammable liquids leads to disastrous condition. So, it is important that the top layer of soil (up to the fixity depth) should be strong enough to provide the required lateral capacity to the pile.
A project for constructing LNG terminal in Odisha containing 2nos of 90m dia LNG storage tanks supported with pile foundation located near to coastal region, to improve the lateral capacity of existing soil, the top 3m was replaced by compacted engineering fill (GSB). The site was a filled-up area with dredged soil from sea, the top 5m-10m were soft to medium stiff clay with SPT N less than 10. The lateral design load on pile was 534kN in free head condition. Actual lateral capacity for the strata was around 300kN under free head condition which was less than required capacity. Therefore, for improving the lateral capacity of site the top 3m soil is replaced with well compacted engineering fill (GSB) in layers of 250mm and the capacity is proved by conducting initial and routine lateral load tests. This paper describes the properties of the engineering fill used and how the lateral capacity of pile was improved to meet the design requirement.
Abstract: Theme 8