The Tallest Wood Building in the World UBC Brock Commons Student Residence Base 3D Model to Product Delivery

Transcription

1 The Tallest Wood Building in the World UBC Brock Commons Student Residence Base 3D Model to Product Delivery Kris Spickler, P.E. Principal Heavy Timber Group Inc Granite Bay, California Nicholas Sills, M.Sc. Structurlam Products LP Penticton, British Columbia Abstract The Tallest Wood Building in the World is currently the University of British Columbia Brock Commons 18 Story residential high rise. The design team members used various 3D modeling software and also chose a virtual design and construction (VDC) modeller to pull all the design data together. The VDC modeller s job was to develop and maintain a comprehensive 3D virtual model of Brock Commons throughout the design phase. The VDC modeller was involved in the Brock Commons Building very early on and was tasked with collecting all relevant project information from the different team members in order to create a singular virtual model of the building with a very high level of detail. The mass timber supplier, Structurlam Products LP, worked with VDC modeller s base model to further Design Assist and bring virtual mass timber products into the model, and then actual products on to the jobsite for installation. This paper presents the design, manufacturing and install approach used from 3D Modelling to Product Delivery. the portfolio is the 53-m-high (18-storey) Brock Commons Phase 1 Building, featuring the first North American use of mass-timber products in a residential high-rise. Figure 1 - Campus Map Background Located on a large forested peninsula on the west side of Vancouver, the University of British Columbia is at the forefront of the global movement to revitalize mass-timber construction and be innovative in the use of engineered wood products in tall buildings. Among the large wood buildings already on campus are the Centre for Interactive Research on Sustainability, the Earth Sciences Building, and the Bioenergy Research and Demonstration Facility. The newest addition to Figure 2 Floor Plan 1

2 in a staggered configuration and secured with plywood splines to create a diaphragm. Panels are 169 mm thick, one bay wide (2.85 m) and of four different lengths to a maximum of three bays (12 m long). There are 29 panels per level and most are unique due to the configurations of pre-cut mechanical, plumbing and electrical openings. Figure 5 CLT to Core Connection Structural System Figure 3 3D Aerial Perspective Columns - The CLT floors and roof are point supported by GLT and PSL columns, arranged in a grid measuring 4x2.85 m. Larger columns (265x265 mm) on the lower levels, and slightly smaller ones (265x215 mm) on the upper levels. PSL columns are utilized at points with higher loads in the middle of the floor plates between levels 2 and 5. Concrete Podium - The concrete podium houses the ground level amenity and service spaces, and supports the wood structure on the second level transfer slab (600 mm thick). The decision to build a concrete podium was driven by a need for large spans independent from the wood column grid, resistance to impacts and to house mechanical and electrical services in non-combustible spaces. Lateral Concrete Cores - The two cores house stairs, elevator shafts and mechanical services. Made of cast-in-place reinforced concrete (450 mm thick), they provide structural rigidity to resist lateral wind or seismic forces along the full height of the building. Figure 6 Typical Column Connection 3D Model Coordination Figure 4 CLT Floor Panel Layout CLT Floor Diaphragm - The floor slabs are composed of CLT panels, oriented on the building s long axis and installed Throughout the design phase of the project, virtual design and construction (VDC) model was used for the following: 1. Visualization - The model was used primarily to create visualizations of different options to assist design development 2

3 and decision making. During the integrated design workshop, the model was updated in real-time to provide rapid feedback as the team assessed different structural systems. 2. Multi-disciplinary coordination - The VDC modeller worked from the consultants 2D drawings and 3D models to create the model. Design changes were updated in the model and any issues were documented and reported back to the team as requests for information or clarification. within production oriented structure. Then certain elements, namely the CLT panels, the GLT and PSL columns and the steel components could use digital CNC fabrication for each as well as for assembly drawings provided by SLP. 3. Clash detection - Due to the prefabrication of significant building elements, the routes for building systems and the associated penetrations had to be planned during design. The 3D model was used to position pipes and conduits, size penetrations and shafts, ensure appropriate clearances and other spatial requirements were met, and resolve major clashes between system routes. 4. Quantity takeoffs - Due to its high degree of accuracy, the virtual model was used for quantity takeoffs of materials throughout the design and preconstruction phases. During the workshop, for example, three structural solutions were modelled and the quantities of timber were extracted to help inform the selection process. Mass Timber members by Structurlam Products LP (SPL) was chosen for the structural wood system. Figure 7 CNC Panel Drawing 5. Structurlam Manufacturing Design Assist A specialty panel was developed with Engineer of Record to meet the project design and specifications. A 169 mm thick 5 layer panel was created using 1650 psi machine stress rated SPF lamella to meet the design requirements. Each panel was modeled and revised for CNC processing and run time for optimization. Refined steel column connections were used to achieve costs and material tolerances required. 6. Constructability sequencing review - A 4D simulation of the installation sequence that was developed from the 3D virtual model provided an overview of the assembly of building elements. This assisted the project team in visualizing the construction process and it helped the team pre-emptively resolve some of the constructability issues that would otherwise have caused on-site delays. Whenever issues or conflicts were revealed in the model, they were communicated back to the consultants, changes were incorporated in the design, and then revisions were directed back to the modellers and SPL the Mass Timber supplier. 8. CNC Digital fabrication The VDC model was able to be used for the Base 3D model with geometry including all holes and penetrations. Adjustments were made by Structurlam for fabrication details and tolerances in the manufacturing 3D model. Naming and production systems were arranged to work Figure 8, 9 Hundegger PBA CNC 3

4 The details for installation sequence are supplied one month prior to 1 st production run. Project members arrive on site ready for installation, in perfect order as modelled. Figure 10 Glulam Column with Caps Construction The Mass Timber installer for this project was Seagate Structures Ltd. The process of practicing through 4D simulation of the installation sequence that was developed from the 3D virtual model provided an overview of the assembly of building elements. And the construction of a fullscale mock-up provided a test of design and planning assumptions in the real world, and validated material choices. Figure 11 Factory Test Fit Shipping Still within the 3D and 4D modelling the project CLT panels are stacked in reverse order of installation and pre-planning for the project installation is done well in advance. Figure 12 CLT Panel placement 4

5 Figure 13 Glulam Column placing Figure 16 Last panel Conclusions Figure 14 Panel placement Due to the innovative nature of the Brock Commons Building, understanding how the building will be constructed including prefabrication of components, trade sequencing, and required equipment is critical to developing a realistic plan for delivering the project on time and on budget. The process of virtually and physically modelling the building helped the design team understand the constructability of their approach, and it helped the team to design the components and connections accordingly. The VDC modelling allowed the design professionals to focus primarily on the building and system designs, and freed them from having to devote time and resources to modelling. Design and constructability problems can be anticipated when the Manufacturing Design Assist modelling overlay s the VDC Base Geometry Model which includes information about connection details and identifies design and system clashes and inconsistencies. Acknowledgements The authors wish to acknowledge the following individuals who helped make this publication possible: Robert Jackson, P.Eng, and Paul Fast, P.Eng, P.E., Fast + Epp Engineers. Ralph Austin Seagate Structures Ltd. References Figure 15 Column point support Brock Commons Case Study by University of British Columbia s Centre for Interactive Research on Sustainability. Published July 2016 Pictures by Seagate Structures Ltd. 5

6 SEAOC CONVENTION PROCEEDINGS