Case Study | 9.10.2015
Designing the Building Envelope for Multi-Hazards
Not just a Blast Design firm: Protection Engineering Consultants provides comprehensive multi-hazard design.
Our clients have come to rely on us for our extensive experience designing building components against blast loads. It requires a deep understanding of how building envelope components are designed and detailed to protect a building and its occupants from a blast event. At PEC, we leverage this insight to provide our clients with one-stop design, analysis, and building envelope solutions for additional hazards such as seismic, wind, and impact loads.
Glazing Systems for Blast, Wind, and Seismic Loads
We routinely work with architects and engineers to design glazing systems for blast, wind, and seismic loads. When beginning a design project, our first step is to develop a complete design narrative that outlines all the applicable hazards with a detailed design approach for each. When faced with multiple hazards it is important to understand how each requirement affects the components, connections, and the overall system. For example, a building in a wind-borne debris region with missile impact requirements will typically require a stronger glazing configuration such as laminated panes with 0.09-in or 0.10-in PVB interlayers. If blast-resistant requirements also apply, and are not coordinated properly, the heavier glazing configuration can cause major complications with respect to connection and component details. PEC works with team members early in the process to coordinate efforts more efficiently so that these complications, and their related expense, can be avoided later.
We routinely work with glazing contractors to design glazing systems to satisfy the specification requirements for blast, wind, and seismic requirements. We use government approved dynamic analysis tools such as SBEDS and SBEDS-W along with internally developed proprietary tools to select and design glazing and framing components for complex protective glazing systems as required by the Department of Defense (DoD), the Interagency Security Criteria (ISC GSA) and Department of Veteran Affairs (VA). Wind and seismic loading calculations per ASCE 7 and calculations per ASTM and material specific design codes are also regularly provided.
Exterior Walls for Seismic Loads, Progressive Collapse, and Blast Protection
There are many buildings that use the exterior walls to resist lateral and gravity loads. In some cases, these exterior load-bearing walls must also incorporate protection against blast loads and progressive collapse. Our understanding of progressive collapse guidelines and non-linear alternate path methods of analysis have allowed us to work with architects and engineers to design and develop effective design details for construction of load-bearing reinforced concrete and reinforced CMU wall systems capable of providing protection against these hazards.
In seismic areas where buildings must also incorporate resistance against seismic loads, heavy wall systems which are often preferred for improving performance against blast loads may have an adverse effect on seismic load requirements. By using a combination of lightweight finishes and appropriate connection detailing, we are able to provide our clients with a solution that can reduce seismic load requirements while simultaneously providing the required level of protection against blast loads. Our engineers have many years of experience in research, testing, and high fidelity modeling of exterior walls and connections against blast loads. We use this experience to work with architects to design precast panels, cold-formed metal studs, and other types of wall systems against these types of hazards.
Doors and Walls with Forced Entry Protection
Some “special” facilities are required to prevent aggressors from gaining entry into the building. Depending on the facility and the response time of security personnel, the façade and entryways (doors) may need to resist the effects of various hand, power, thermal and explosive tools for predetermined delay times.
PEC engineers have more than 30 years of experience in developing designs and testing wall and door cross-sections for forced entry resistance. We also have significant experience in selecting and specifying the required access, operators, and locking mechanisms for these doors.