Analysis and Design Of Berthing Structures

Abstract

The topic of “Analysis and Design of Berthing Structures” seems to be a new subject to common Structural Engineers, but one of the important structure contributing to the development of trade in our nation. The problem selected for the said topic is the Proposed 12th Cargo berth at Kandla, which is a Open Piled Structure with retaining wall at the land side. Such Structure is also referred as “Wharf”. The most important part of the study is the force calculation for such massive structure and predict the worst load combinations among various forces such as cyclone, high tide, earthquake, high winds, heavy live loads etc. In order to understand this, a study was made on IS-4651:1989 and the loads being calculated as per the given clauses and combined as per norms given in code. A 3D model was generated using STAAD.Pro software and the analysis was carried out with the appropriate loads acting on the structure. The results so obtained were used to design the structural components. Here it should be noted that the Berth is designed for a Vessel having capacity of 75000 DWT and the structure is supported on Bored cast-in situ piles. It was observed that the seismic force was governing in most of the cases because of Kandla being located in Earthquake Zone V. One of the most important aspect of this structure was the use of Pneumatic Fenders which are no doubt very costly but very efficient enough in absorbing kinetic energy during berthing phenomena. Thus a very low reaction force was obtained with pneumatic fender compared to cell type fender. The soil mass which is retained by the retaining wall is then treated so as to consolidate and allowed to settle for 2 to 3 years and then the soling treatment is done above it after compaction, and thus Open Stacking Ground is available for storage of heavy containers.