Most of the seismic load on the retrofitted URM structure will be resisted by the wood diaphragms. It may be necessary to strengthen the diaphragm with additional fastening or replacement of the diaphragm sheathing.
The lateral diaphragm forces need to be transferred into the walls. Often, the attachment of the blocking or rim joist to the walls is inadequate or missing. New shear anchors can be installed to transfer the horizontal diaphragm forces into the walls.
AT-XP® is a fast-cure, all-weather, high-strength anchoring adhesive and may be used to anchor threaded steel rods or deformed steel reinforcing bars in unreinforced masonry.AT-XP High-Strength Adhesive
ET-HP® is an epoxy-based system for use as a high-strength, non-shrink anchor-grouting material and may be used to anchor threaded steel rods or deformed steel reinforcing bars in unreinforced masonry.ET-HP Epoxy Adhesive
Screen tubes are used in hollow base material applications to contain adhesive around the anchor and prevent it from running into voids.Steel Adhesive-Anchoring Screen Tubes
Angles transfer shear forces for wood to wood framing connections. The A35 with 1/2" long screws might be used to transfer shear forces from 1/2" minimum thickness sheathing to wood framing connections.Angles
Hand-drive or collated screws may be used to enhance wood diaphragm strength. Strong-Drive structural wood screws may be used for connector or steel to wood connections.Screws
Hand-Drive or collated nails may be used to enhance wood diaphragm shear strength or for wood to wood or steel to wood connections.Nails