Håltagning i limträbalkar : Påverkan och dimensioneringsförändringar

Sammanfattning: Approximately one fifth of Sweden’s total emissions of greenhouse gases originate from the construction and real estate sector. In order to minimize the climate footprint in the construction industries, the endeavor is to use as environmentally friendly and sustainable processes and materials as possible. Thus has wooden structures had a recent upsurge where generally more buildings are constructed by wooden materials.  Glulam is often used where the requirements regarding a materials strength is high. Glulam beams are a suitable option as loadbearing constructions in framing of joists. Piercing is frequently required in framing of joists as a result of needed space for ventilation ducts and drain pipes. There is no formally accepted method in Eurocode where piercing is treated. Thus WSP has an interest in what extent piercing of glulam beams is possible.   The purpose of this study is to increase the knowledge regarding the impact that piercing has on a beams load bearing capacity. To examine the impact, three beams of different dimensions are considered where piercing is made in three different placements on the respective beams.  Firstly manual calculations are made by the standards in the Glulam handbook. The results from the method are then checked regarding bending and shear stress. The purpose of the calculations is to determine the maximum hole size and the holes impact on the load bearing capacity for each beam. The methods follows several geometric requirements presented in the Glulam handbook. Similar calculations was also made in Statcon Post&Beams. Statcon is a dimension tool for constructors. A verification of the results from the calculations made by hand was also made.  Lastly the results are presented and analysis is made. Some of the conclusions made were that both calculation methods indicated that piercing should be made as centered as possibly on the beam. The geometrical requirements are a limiting factor since the maximum hole size were restricted on 22 of the 29 beams, even though the calculations proved that bigger holes were possible.