Designing Mass Timber Construction to Mitigate the Potential for Disproportionate Collapse
November 19, 2025
2:00 PM to 4:00 PM Eastern Time
1:00 PM to 3:00 PM Central Time
11:00 AM to 1:00 PM Pacific Time
Mark Weaver, S.E.
Since the Ronan Point Apartments incident in 1968, there has been a push to inculcate design and detailing measures into mid and high rise buildings that would mitigate the potential for disproportionate collapse in the wake of an extreme loading event (e.g., explosion). At the present time, UFC 4-023-03 ``Design of Buildings to Resist Progressive Collapse`` is used by the Department of Defense, Department of State, and other entities to define design requirements aimed at reducing the potential for disproportionate collapse. Since 2016 (i.e., the year UFC 4-023-03 was last updated), there has been growth in the use of mass timber structural systems in buildings constructed in the United States. As such, an effort was recently completed that updated UFC 4-023-03 specifically for mass timber systems. This presentation describes the updated provisions to UFC 4-023-03. Furthermore, a design example that illustrates the primary strategies that can be utilized to mitigate the potential for disproportionate collapse of mass timber buildings is described in detail. K&C, LERA, and KPFF, who each have experience in designing mass timber structures for progressive collapse resistance, worked closely with the U.S. Army Corps of Engineers Protective Design Center to develop these UFC 4-023-03 updates.
Audience Learning Objectives
- To understand the extent of the disproportionate collapse mitigation testing performed on mass timber components to date.
- To understand potential collapse mechanisms for mass timber buildings.
- To learn strategies for safely designing and detailing mass timber buildings to mitigate the potential for disproportionate collapse.
Speaker Bio
Mark Weaver, S.E., is a Principal at K&C with over fifteen years of structural design engineering experience that has largely focused on designing infrastructure to mitigate the effects of blast, impact, and shock loads. He leads many of K&C’s applied research and testing programs involving hardened structures as well as design efforts aimed at developing innovative structural solutions capable of protecting people and critical infrastructure in the event of malicious man-made and accidental explosion threats. Mark is also actively engaged with professional organizations and committees devoted to advancing the state of the art in protective construction. He is currently the chair of the ACI 370 “Blast and Impact Load Effects” committee and vice chair of the ASCE “Blast Protection of Buildings Standards” committee.
Mark Weaver, S.E., is a Principal at K&C with over fifteen years of structural design engineering experience that has largely focused on designing infrastructure to mitigate the effects of blast, impact, and shock loads. He leads many of K&C’s applied research and testing programs involving hardened structures as well as design efforts aimed at developing innovative structural solutions capable of protecting people and critical infrastructure in the event of malicious man-made and accidental explosion threats. Mark is also actively engaged with professional organizations and committees devoted to advancing the state of the art in protective construction. He is currently the chair of the ACI 370 “Blast and Impact Load Effects” committee and vice chair of the ASCE “Blast Protection of Buildings Standards” committee.