CASE STUDY
MIXED-USE TOWER
DEVELOPMENT
Structural engineering for a mixed-use high-rise tower in Burnaby featuring concrete core walls, post-tensioned transfer slab, and deep foundation system for a seismically active site.
CASE STUDY
MIXED-USE TOWERDEVELOPMENT
Structural engineering for a mixed-use high-rise tower in Burnaby featuring concrete core walls, post-tensioned transfer slab, and deep foundation system for a seismically active site.
PROJECT OVERVIEW
This project delivered structural engineering for a mixed-use high-rise tower in Burnaby, BC, comprising commercial retail at grade, office floors on the podium levels, and residential suites above. The tower's structural system used a reinforced concrete core wall for lateral resistance combined with a post-tensioned flat plate for gravity framing.
Zagrosia Engineering provided full structural design services from schematic engineering through construction administration, including dynamic analysis of the concrete core wall system, post-tensioned slab design, transfer slab design at the podium-to-tower transition, and deep pile foundation engineering.
PROJECT DETAILS
- LocationBurnaby, BC
- Building TypeMixed-Use High-Rise Tower
- ServicesHigh-Rise Structural Design & Seismic Engineering
- JurisdictionCity of Burnaby
- CodeNBCC 2020 / BCBC 2018
- ExpertiseP.Eng — British Columbia
THE CHALLENGE
The tower's height and Burnaby's high seismic hazard required a dynamic analysis of the concrete core wall system per NBCC 2020 seismic provisions. The ductile core wall system demanded special detailing of boundary elements, coupling beams, and base connection to the foundation — all requiring careful coordination with the concrete contractor's forming capabilities.
The transition from the larger-footprint podium to the smaller tower floor plate required a post-tensioned transfer slab to redirect gravity loads from eliminated columns above. The transfer slab design governed many foundation loads and required iterative coordination between the slab design and the pile foundation sizing.
ENGINEERING APPROACH
Dynamic Seismic Analysis
Response spectrum analysis performed for the concrete core wall system. Ductility-related and overstrength-related force modifications (Rd, Ro) applied per NBCC 2020 for moderately ductile core walls.
PT Slab & Transfer Design
Post-tensioned flat plate floors designed for residential and office loading, with the transfer slab detailed as a post-tensioned band beam system to span the eliminated podium columns.
Deep Foundation Design
High-capacity cast-in-place concrete piles designed for the combined gravity and seismic overturning loads, with pile caps designed for biaxial moment transfer from the core wall base.
SCOPE OF WORK
Core Wall Seismic Design
Dynamic analysis and ductile core wall design with boundary element and coupling beam detailing
PT Flat Plate Design
Post-tensioned slab design for all residential and office floor levels
Transfer Slab Design
Post-tensioned band beam transfer system at the podium-to-tower transition level
Deep Foundation Engineering
High-capacity cast-in-place pile design for gravity and seismic overturning demands
Construction Administration
Site observation, RFI management, and shop drawing review throughout construction
OUTCOME
COMPLEX STRUCTURE, DELIVERED ON BUDGET
The mixed-use tower was completed within the project schedule and budget. The dynamic seismic analysis was accepted by the peer reviewer without major revision, and the post-tensioned transfer slab was constructed without incidents. The tower has been fully leased and occupied since project completion.
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DO YOU WANT TO START YOUR PROJECT?
Every project is unique. Contact us to discuss your specific requirements, and discover how we can help.
DO YOU WANT TO START YOUR PROJECT?
Every project is unique. Contact us to discuss your specific requirements, and discover how we can help.