Jämförelse mellan dimensioneringsmetoder av prefabelement med avseende på fortskridande ras

Sammanfattning: Progressive collapse is nowadays an important subject when building prefabricated constructions due to the weak connections between the elements. The instructions for designing with regards to progressive collapse given by the Eurocode is unclear, there is no clear indication on how the method shall be used, when it shall be used or how it shall be used.Sweco Structures AB is a company that wants to prevent this kind of problem by comparing three designing methods on three different cases that is used a lot in constructions nowadays. The comparison is made by using same conditions for all the methods with focus on vertical joints and then compares the result with robustness as the main purpose.In order to get to the results, excel templates was made for every method to simplify the calculations, concrete companies and experts were contacted, information from literature was gathered and mentors in the company as well as in school shared their knowledge.After producing an excel template for each method and gathering theory a result was summarized for each type of case.For case 1 where a wall element is connected to two columns, the cohesion method or the key-element method is recommended. Cohesion is a method that is used in a calmer environment where the risks for accidents like explosions and impacts are minimally meanwhile key-element is used in a environment that has higher risk for accidents. The environment where the design is located is crucial to which one of these two methods that shall be applied to this type of cases like case 1.Alternative load path is the most optimal method for case 2 where two wall elements is connected to each other vertically and case 3 where two wall elements is connected to three columns. The method is chosen on these cases due to the robustness it gives the building and because its economical.