Update to UFC 3-340-02 for Blast Resistant Design of Masonry Components

The Department of Defense Explosives Safety Board DDESB has funded Protection Engineering Consultants PEC to update the Chapter 6 sections on blast resistant design of masonry components in UFC 3-340-02, Structures to Resist the Effects of Accidental Explosions. Under this tasking, PEC will apply data from recent research and testing to develop new and updated analysis and design procedures for masonry walls. These procedures will be specifically written to satisfy the explosives safety requirements of DoD 6055.09-STD, DoD Ammunition and Explosives Safety Standards. Wherever possible, the new UFC criteria will be written to be consistent with the current state-of-the-practice for conventional masonry construction. As part of this tasking, PEC will identify areas where more research and testing are recommended. The revised sections will continue to apply single-degree-of-freedom SDOF analytical models, but design procedures will be updated, in accordance with current industry practice, to use vertical steel reinforcing bars for flexural reinforcement. Flexural response criteria also will be revised. New guidance will be added on the analysis of existing unreinforced masonry components assuming brittle flexural response and arching from axial loads. References to applicable ACI 530 and ACI 318 requirements will be added, and masonry shear strength and rotational restraint provided to masonry walls by the foundation system will be addressed.