This thesis work is carried out in Cargotec Sweden AB, Bromma Conquip to study the behavior of load carrying welded joints in different weld metal strength mismatch conditions and various penetration ratios. Static and fatigue strength calculations have been made using FEA and experimentation. The joint in the Telescopic beam of the spreader STS45 has been analyzed. Telescopic beam is one of the critical and main parts in the spreader, which is directly subjected to the load of containers at various ports. Previous studies show that this joint limits the strength of the spreader, it has thus been analyzed. To check the effect of different strength mismatch conditions in the weld metal, static strength calculations have been carried out. The effect of different penetration ratios on static and fatigue strength has also been studied. A cruciform test specimen is designed according to the joint configuration and the capacity of testing machine. Criteria for the selection of consumables has also been developed and following standards: Eurocode 3, AWS D1.1 and BSK07, have been compared for static joint design. Sub modelling, effective notch stress and beam theory techniques have been used to study the effect of weld metal penetration and size of weld throat on the fatigue strength of the welded joint in the Telescopic beam. The study show that matching or slight under matching in the filler material along with full penetration increases the ultimate strength capacity as well as the ductility in the joint. Results of Eurocode 3, AWS D1.1 and BSK 07 are close to each other. Apart from strength mismatch and penetration ratios, it is observed that the weld geometry and joint preparation has also effect on the strength of the joint. Fatigue analysis of the weld in the Telescopic beam using 3D Finite element analysis show that effective notch concept is not applicable to this part of the spreader.

The subject of the presented thesis is a foundation pit dewatering numerical analysis. The study is introduced with practical examples and the summary of the necessary theory. Individual subtasks are modeled as two or three-dimensional problem on a chosen foundation pit example. A comparison with analytical methods and theoretical knowledge about the problem is made. The studies focus on specifying the pumped water quantity, the shape of the depression curve, determining the size of the numerical model and the influence of the finite element network density. The steady-state flow cases, water table aquifer, a well system, sheet pile wall cutoff effect, surface drained pit and partial penetration cases are analyzed. The work proposes a method of modeling a well by FEM. The main output is a 3D analysis of a submerged excavation dewatered with a partially penetrated well system.