The doctoral thesis of the student Ibtisam Ahmed Jarah was discussed in the College of Engineering, University of Basra, Department of Civil Engineering, entitled The optimal design of marine dock facilities under the influence of dynamic loads. This thesis addresses the optimal design of a marine berth structure under dynamic loads, focusing on the Um Qaser container berth. The analysis was conducted using ABAQUS finite element software. Newmark's direct integration method was applied, and the nonlinear solution was achieved using the Newton-Raphson method. The structure was modeled utilizing a two-node beam element for the steel piles and beams, a four-node thick shell element for the concrete deck slab, and an eight-node brick element for the soil. Three types of supporting piles were considered: fixed-end piles, piles embedded in elastic soil, and piles embedded in elasto-plastic soil. Each model was analyzed across eight different load combination cases to design for allowable stress and load factor design. Notably, the elasto-plastic soil model under the ship impact load combination yielded higher results than other supporting and loading cases of the structure. Optimization studies were conducted using MATLAB, employing the multi-objective optimization goal attainment method (MOGA) to solve a fourth- and fifth-degree polynomial function that models the relationship between stresses and design variables. The primary objective was to develop a container berth structure capable of withstanding greater stresses than the existing structure. The design process involved three key variables: pile diameter, spacing between piles, and the thickness of the deck slab. For the first variable, the pile diameter, eight diameters ranging from 800 mm to 1500 mm, were evaluated. Four additional parameters were analyzed alongside the diameter to determine the optimal diameter. The first parameter is to change the distance between the piles, which are three spacing (4D, 5D and 6D) where D is the diameter of the pile. The second parameter includes the change in ship impact load using three loads, which are 150, 200 and 250 tons. The thickness of pile diameter is changed throughout the third parameter using thicknesses of 17, 20 and 23mm. the fourth parameter is done by changing the depth of the piles embedded in the soil, where three depths were used, namely 15, 18 and 21 m, where the results obtained from the four parameters showed that the diameter of 1000 mm is the optimal diameter for the berth piles.
The second variable for the optimal design is the spacing between the piles, where eight different distances were chosen, starting from 3D to 6.5D. the study included two parameters with the spacing: the first parameter changed the diameter of the piles using four diameters 800, 1000, 1100, and 1300 mm, while the second parameter changed the ship impact load using three loads, which are 150, 200, and 250 tons, where the optimization results showed that the 3D spacing is the best distance for both parameters.
The third variable for the optimal design is the thickness of the deck slab, eight different thicknesses were chosen for the study, starting from 60 cm to 130 cm. Two cases were studied for this variable : the first case changed the diameter of the pile using four diameters 900, 1000, 1100, and 1300 mm, while the second assessed is applying different sets of compound loads. The results obtained from the two cases showed that the thickness of 80 cm is the value ideal for the container berth deck, as it gave optimal results than rest of the deck thicknesses.
.jpg)
