Seismic retrofitting is a process that modifies existing structures to make them more impervious to events such as earthquakes and tremors. If you own an existing tilt-up or non-ductile concrete building in an earthquake-prone area and want to be confident that it will withstand a natural disaster, seismic retrofitting is an excellent strategy. Depending on the type of building you own, different techniques will be used to retrofit your building.
Seismic Retrofitting Techniques for Concrete Tilt-Up Buildings
Roof to Wall Anchors: A fundamental element of many seismic retrofitting projects, roof to wall anchors offer your building extra structural support that helps its roof to wall connections sustain vibrations from earthquakes and other natural disasters more effectively.
Continuity Ties: Continuity ties are another key strategy for seismic retrofitting in concrete tilt-up buildings. These connect two structural elements together in order to amplify your building’s earthquake resistance by creating a more stable structure that distributes the impact of seismic vibrations more evenly.
Braced Frames and Concrete Footings: Braced frames and concrete footings are not used every time a concrete tilt-up building undergoes seismic retrofitting. Seismic retrofitting experts will examine the geometry of your building’s structure to determine whether these supports will be an effective seismic retrofitting strategy.
Roof Nailing: Like frames and footings, roof railing may not be necessary for every seismic retrofitting project. However, it can provide significant additional strength to your roof structure, and it is an efficient step to add if your building already requires other re-roofing work.
These are the most common techniques used but due to the particular building there may be more items that need to be completed.
Seismic Retrofitting Strategies for Non-Ductile Concrete Buildings
Gunite Walls and Columns: When a non-ductile concrete building undergoes seismic retrofitting, a key goal is reinforcing its existing columns and walls with more durable, structurally sound materials. Seismic contractors often use Gunite walls or Gunite existing columns for this purpose, sometimes in conjunction with additional concrete footings that may include, micro piles, or helical anchors for additional uplift resistance..
FRP Columns and Walls: Fiberglass-reinforced polymers (FRP) columns and walls are another key technique in seismic retrofitting for non-ductile buildings. Like Gunite, FRP is a tough, durable material that adds further support to your building’s structure.
Draglines: Draglines, which can be used in conjunction with steel and concrete materials, help keep non-ductile buildings supported and stable during earthquakes by connecting and dragging loads to more areas and components of the building.
If you are curious about which seismic retrofitting processes might be the best safety investment for your building, contact Saunders Seismic.