Rock Type and Berthing Velocity of 80000t Vessel on Design of Berthing Structure

A berthing structure is a port and harbour structure to which the vessel is securely berthed and moored. The design of berthing structures depends on various factors such as vessel characteristics, embedded soil/rock, the berthing velocity which depends on site and berthing conditions. The behaviour of the berthing structure for different grades of embedded rocks and different berthing velocities is studied through numerical analysis using STAAD PRO. In order to carry out conceptual design the embedment length of pile is to be assumed. The fixity depth and embedment length for piles in rock is assumed based on the requirements of long flexible piles as per IS 2911 Part 1/Sec2. The berthing force for different berthing velocity corresponding to site and berthing condition as per IS 4651 code and analysis of pile supported berthing structure for five grades of weathered rocks are carried out. For each type of rock, as the berthing velocity increases, the increment in diameter of the pile is more compared to the increment in the length of the pile. For each berthing velocity, as quality of rock increases, decrement in the embedded length of pile is more compared to decrement in diameter which leads to decreased slenderness ratio of pile and less lateral deflection of pile. The design charts are also developed for fixity depth, embedment depth, percentage of steel, diameter of pile etc satisfying the crack width limit for berthing structure with four rows of pile considering all possible load combination.