CNA Security: Structural Solutions for Secure Office Environments

Project Overview

BKBM Engineers provided structural engineering services for a 130,536-square-foot, three-level office building constructed above two parking levels (including one below grade) in downtown Sioux Falls, South Dakota. As a trusted structural engineering firm in Sioux Falls, BKBM supported the project’s goal to maximize usable space and resilience while optimizing urban site constraints.

Project Drivers: Values & Vision

The project team prioritized safety, durability, and access, recognizing the building’s prominent downtown location within the floodplain of the Big Sioux River. The vision centered on creating a modern, accessible workplace while ensuring robust floodplain engineering and long-term reliability for occupants and owners.

Key Challenges & BKBM Solutions

  • Parking Solutions: The two-level parking structure features precast concrete decks supported by cast-in-place retaining walls, providing capacity and secure vehicle access, with one level innovatively designed below grade.
  • Resilient Office Construction: The office tower above uses composite steel decking, structural steel framing, and cast-in-place shear walls for strength, flexibility, and open office layouts.
  • Floodplain Engineering: Special attention was given to the below-grade parking, engineered to withstand saturated soils and flooding conditions associated with the adjacent Big Sioux River, ensuring building integrity and occupant safety.

Collaboration & Community Engagement

BKBM worked closely with local architects, city officials, and project stakeholders to address regulatory requirements, site constraints, and community needs. This collaboration reflects our commitment to partnership and responsive engineering service.

Cultural Heritage & Environmental Stewardship

By delivering innovative floodplain engineering and efficient mixed-use design, the project contributes to Sioux Falls' downtown vitality while respecting the local environment and community heritage.

Results & Impact

  • The completed office building offers:
    • Resilient and flexible workspace for businesses
    • Secure, efficient parking in a flood-prone urban location
    • Enhanced value and confidence for building users, owners, and the broader community