Urm Building Retrofitting With Concrete Wall

Adding shotcrete bonded to the urm wall.

Urm building retrofitting with concrete wall.

Abstract there are many complex considerations when seeking to seismically retrofit unreinforced masonry urm buildings. And adding shear elements. Th e urm problem in jurisdictions that are now eff ectively enforcing the current building code essentially the latest edition of the international building code the ibc is due to those buildings that were built before recent model code seismic pro. The walls of a concrete tilt up building can weigh between 100 000 and 300 000 pounds.

Retrofit construction of urm buildings. Earthquake retrofitting services for unreinforced masonry buildings urm unreinforced masonry buildings are especially vulnerable to earthquakes. A lot of damage to urm buildings can be attributed to parapet failures when a seismic event occurs. Bracing the parapets is a must when evaluating the needed retrofitting of a urm building.

Anchoring walls to diaphragms. Buildings built of unreinforced masonry urm brick hollow clay tiles stone concrete blocks or adobe are very likely to be damaged in earthquakes because the mortar holding the masonry together may not be strong enough to resist earthquake forces. Developing successful risk reduction programs states more than any other kind of construction this type of building can be singled out as being seismically vulnerable. In fact the fema report unreinforced masonry buildings and earthquakes.

The damage can occur not only to the building itself but to nearby buildings and poses a major risk to life safety. Shear walls or concrete overlay walls are often installed over the inside face of existing walls and epoxy doweled to the brick. Or adding a fiber composite layer epoxy embedded fiberglass mesh. Experience with thousands of urm buildings has identified four major aspects of seismic retrofitting.

2 3 wall anchorage. Strength requirements need to be evaluated and the intrinsic strength of. This entails strengthening the walls through various methods such as adding strongbacks or secondary support members to the wall. That this existing urm building stock presents a problem with respect to earth quake risk.

Preventing the collapse of the walls particularly load bearing walls is critical in urm buildings. Concrete or shotcrete shear walls are a commonly used seismic retrofit technique. Diaphragm repair and strengthening. Wall repair and strengthening.

The code requires some 8 000 urm buildings to be retrofitted vacated or demolished. Similar to steel frame schemes the existing brick provides no resistance to seismic forces and the new concrete resists all loads. Adding a layer of steel reinforced concrete. All masonry should be reinforced.