A multidisciplinary project at Universidad Católica de la Santísima Concepción, supervised by the Delft University of Technology. Coquimbo is a port city approximately 400 km north of Santiago and lies next to La Serena. Coquimbo was recently hit by a tsunami on the 16th of Septe
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A multidisciplinary project at Universidad Católica de la Santísima Concepción, supervised by the Delft University of Technology. Coquimbo is a port city approximately 400 km north of Santiago and lies next to La Serena. Coquimbo was recently hit by a tsunami on the 16th of September 2015. Most damage occurred in Coquimbo Bay, which is the scope area of this project. The area consists of a beach, a damaged seawall, wetlands, and the Altamar highrise. Due to the damage caused by the previous tsunami and the poor socioeconomic background of the surrounding neighborhood called Baquedano, the Chilean authorities are planning to redevelop the area. In front of Coquimbo a large seismic gap exists since 1922, which makes the probability of an earthquake and corresponding tsunami in the near future very high. This situation leads to the attention for the project; to find a new and integrated purpose of the project area, enhancing public values and improve the safety concerning a possible future tsunami. Functional aspects for the area as improving the safety against tsunamis, redeveloping the ecology of the wetlands, and increasing the welfare of the neighborhood results into 5 alternatives. With the NEOWAVE software a tsunami generation, propagation and impact is modeled. The bathymetry is modified conformthe different alternatives for the Coquimbo Bay area and a realistic earthquake scenario is chosen to model the inundation depth and flow velocity of the tsunami impact. Inundation maps and flow velocity data measured at important tide gauges provide information about the tsunami impact in the different alternatives. This information is used to assign a score to the safety criteria in the multi criteria analysis. Besides safety, also nature & recreation, welfare of the neighborhood, visual hindrance, infrastructure, construction process, and durability & maintenance are criteria that are assessed from the stakeholders point of view. Based on the score from this multi criteria analysis, the costs of the alternatives and a preference for a multifunctional solution alternative II is chosen as the best integral solution. This alternative includes an elevated coastal road with floodgates to reduce overtopping and to control the return flow of a tsunami. The wetlands are to large extend restored to their former configuration and the dynamic behavior of the wetlands is stimulated. Part of the coastal protection is defined as a multifunctional boulevard. For the remaining part of the coastal area 3 different possibilities are considered: a reflective L-Wall, a ground dam with a natural slope, or a dam of reinforced soil. Using NEOWAVE simulations the economically optimal height of the coastal protection is determined to be 5mfrom sea level. With a coastal protection of this height an average maximum inundation of 2,72 m in the Baquedano area is expected. Besides that, the coastal protection retains the first out of 3 incoming tsunami waves which increases the evacuation time. All options for the configuration of the coastal road are conceptually designed, loaded with tsunami forces and checked for several failure mechanisms. It turns out that horizontal stability and rotational stability are the decisive failure mechanisms. Based on the lowest costs and the highest aesthetic implementation the option with reinforced soil is the best solution. Furthermore the possibility of the Altamar highrise, which is located in the project area, as a vertical evacuation refuge is investigated. A model of the building is created in Etabs using the official structural drawings and information provided by the local authorities. Assumptions on the einforcement ratios and several structural element dimensions are made due to limitations in project time. A non-linear time history analysis for the earthquake loading is performed using amplified records from the September 2015 earthquake. Subsequently the tsunami forces are modeled and applied. A mesh refinement study and alpha-variation study are performed. The alpha factor determines the amount of numerical damping applied to solve the equilibrium equation in the non-linear time history analysis. Due to hardware limitations the mesh refinement study is not finished, but fortunately a value of 0 can be used for alpha which implies no numerical damping is necessary. The obtained model results are evaluated in terms of stability, displacements and story drifts. It is concluded that the Altamar building fulfills the structural demands and remains perfectly stable. With the availability of an additional evacuation building a new evacuation plan for Coquimbo Bay is created. The new coastal protection decreases damage and the probability of loss of life by increasing the evacuation time. New evacuation routes and a smaller inundation in the Baquedano area increase the safety for the area. It is recommended that further investigation should contain multiple tsunami scenarios with a finer grid size and a probabilistic calculation on the damage in the Baquedano area.