Two School of Engineering students recently represented their team at the 2017 CSCE National Capstone Design Competition, placing third.
Their project, titled "Cross Laminated Timber for Mid-rise Application", was developed over a period of 8 months in their final year of study.
Cross-Laminated Timber (CLT) is a panelized system of construction consisting of stacked perpendicular layers of dimensional lumber glued together into panels. The high level of prefabrication, their quick erection time, and their sustainability meet the current needs of the construction market. This project aimed to identify the structural feasibility of using CLT panels for mid-rise construction using a case study of a 7-storey multi-residential structure.
For the project, the panels were sized to meet five criteria: moment resistance, shear resistance, fire load resistance, deflection and vibration control. Moment, shear and deflection calculations used the mechanically jointed beams theory, which derives a connection efficiency factor to model the rolling shear action of the cross-layers. A load take down was done on the critical section by using SAP200 Analysis. A 3D finite element analysis was performed to verify the previous calculation and to ensure the structural integrity of the whole building. The model was built using Dlubal RFEM software.
In order to meet building code requirements, wood buildings over six-storeys must prove through scientific study that the construction materials used will meet three criteria: structural resistance (2-hr fire rating), fire separation, and insulation.
The team designed a mid-rise building out of CLT to test the material’s structural feasibility for such applications. They were able to ensure the building met BC and National building code requirements for gravity loading and fire resistance. Furthermore, the design included a manufacturing model, ensuring Canadian technology could be used to produce the panels. CLT offers a sustainable and cost-competitive alternative to traditional building methods. With its suitability for mid-rise application, CLT could represent a new market opportunity for the construction industry.
Following graduation, Mathieu Forcier began working for Emil Anderson Construction on Vancouver Island, while Moritz Kohler has been accepted into the Master Program in Integrated Wood Design at the University of Northern British Columbia.