Vietnam is one of the five countries that is severely affected by the consequences of climate change. The extreme weather conditions and the increase of the sea level results in floods in the Mekong Delta, located in the South of Vietnam. Can Tho city, found in the heart of the Mekong Delta, is one of the cities that copes with water related issues on a regular basis. To be prepared for the future, the environmental and infrastructural issues need to be tackled. The resiliency of Can Tho got included of the World Bank program. The objective of this project of the World Bank is to reduce the flood risk in the urban core area and to improve connectivity between the city centre and the low risk urban growth areas. The structural solutions of the polder will be sluice gates, tidal sluice gates, the construction of river embankment, rehabilitation of the drainage system and constructing two regulation and water retention lakes. Additionally, building dykes with new roads and expanding or building new bridges will increase the connectivity of the city. All these measures will contribute on the resiliency of the city. The aim of this report is to identify the impact of the polder on the city, considering the infrastructural and the hydraulic aspects. To measure the impact, the current situation is simulated into two models, an infrastructure model and a hydraulic model. The results of hydraulic model show whether and when locations are flooded, whereas the aim of the infrastructure model is to identify flows on the network, the connectivity of the city and the flow changes after implementation of the new roads.

The aim of this thesis is to propose a simple technique to estimate the maximum impact forces acting on bridge piers in the event of ship collisions. This technique is determined for Dutch commercial inland waterway ships (CEMT classes) and set up to be applied by bridge engineers to determine the required bridge pier strength. Many collision events on bridge piers have occurred in history where some led to a major failure of the bridge deck due to insufficient strength of the bridge pier. The accuracy of the Dutch guideline on calculating these impact forces (ROK 1.4) is questioned, mainly regarding the generalisation of the guideline to different ship types. Therefore, an investigation on this topic has been initiated to provide more accuracy in the estimations on bridge pier impact forces in the event of ship collisions. A dynamic nonlinear finite element model has been created using ABAQUS/Explicit to simulate the ship-bridge pier collision event. The bridge pier is assumed to be rigid and fixed, while the ship structure is assumed to dissipate all initial kinetic energy through plastic deformation (crushing of the structure). Material properties have been obtained from a test database and include rate effects. It has been concluded that the numerical calculation model is verified as stable, and results are in agreement with existing calculation methods. Numerical simulations have been performed on one class IV and two class V ship's bow structures. A relationship between initial kinetic energy levels and maximum impact force has been developed based on the results of the numerical calculations. With the established expression, the estimated impact force can be calculated for the event of a ship collision, given an initial kinetic energy level involved in the collision event. Maximum impact force values have been presented for different ship classes using this expression. For ships smaller than a medium-sized ship (CEMT IV), the impact force values are higher than is found in the current Dutch guideline. However, lower impact forces are estimated for ships larger than this medium-sized ship. This difference mainly originate from the relatively stiff response of the frontal part of the analysed ship's bows, compared to the ship's bow structure that led to the current Dutch guideline. With the proposed impact force expression, the maximum impact force on bridge piers in the event of ship collisions could be estimated with increased accuracy.