Dimensionering av bärverk av stål : En jämförelse mellan Eurokod och BKR

Sammanfattning: The design regulations of Boverket (BKR) have long been the mandatory standard for construction design in Sweden. However from the end of the year 2010, the BKR will be replaced by the European standard Eurocode (EC). The transition to EC has been delayed and it is not until the second of May 2011 that the use of EC will be mandatory. Because EC and BKR differ from each other it is highly interesting to investigate and explain these differences. The purpose of the thesis is to compare the two standards and investigate how they give different results or not for the dimensioning of structures of steel with associated loads. The current project HVC (Pets Science Center) in Uppsala is used as a model for the design of the steel structure used in this study. The investigation is divided into two parts: the calculation of loads and the dimensioning of the steel structure. The internal forces in the construction that are used for the dimensioning are calculated with finite element programs (FEM-programs). The calculations for the comparison of the dimensioning of the steel structure are thereafter calculated by hand according to the current standard of each. Eurocode 3 (EC 3) is the current standard for EC and for BKR the current standard is the handbook for steel structures (BSK 07). The compared parts are: •the control of flexural buckling of a framework brace towards compression force and bending, •the control of a framework brace towards tension force and bending, •the control of a column against compression by a pure normal force, •and the control of a welded joint between a framework brace and an underlying beam. The results from the dimensioning are presented separately in the report and show that in almost all cases of design a lower grade of utilization is obtained for EC 3 than BSK 07. The largest obtained difference is when the dimensioning of a framework brace towards compression force and bending is made there the relationship between the utilization rates are 0,80. The results show that dimensioning according to EC 3 probably will lead to decreased costs within the construction sector, mainly in materials because smaller dimensions are required.