Los Angeles Earthquake Retrofit

soft-story building

Los Angeles is considered to be the second-largest city in the US and since its establishment in 1781 the city has had several nicknames. Most of the people around the world know the loose translation of the city’s name: City of Angels and other quite known nicknames are - the city of Sunshine and Flowers, Lala Land and of course, Earthquake Central - this name is dedicated to the actuality of the Los Angeles Earthquake Retrofit.

Over 10,000 quakes occur in Southern California every day, according to the United States’ Geological Surveys. All of those are so small that people do not even notice them, and the last big earthquake hitting the Los Angeles area was Ridgecrest quake on July 4 and 5 of 2019. The first quake registered 6.4, but the second one hit 7.1 on the Richter Scale.
Fortunately, those two earthquakes could not cause any major damage to city structures and properties, unlike the Northridge Earthquake of 1994. Since the time, after Northridge’s caused loss, the city of Los Angeles has implemented its Seismic Retrofitting Program.
Here we are presenting everything you should know about retrofitting and the process.

Find a Qualified Retrofitting Company

This scale of construction projects is not a DIY type of thing, for there is a range of steps that need to be performed to pass the final inspection of the city. Since the seismic retrofitting Los Angeles program started u number of companies have appeared on the field offering retrofit services, but it is now a problem to find a qualified retrofitting company for the proper construction works. Like any construction project, you need to get a few bids before choosing the company you want to hire.

First, take your time to check their experience and qualifications, if it is possible, their previous clients’ reviews too. Find out what services they offer, for example, do they help with the paperwork? Know if there is someone available to answer your question and is there a structural engineer on their staff? Make a shortlist of the companies you are interested in, then make a call to schedule an inspection of your property.

Initial Inspection For Retrofitting

To complete initial inspection for retrofitting, a qualified contractor or an engineer is needed. Many companies offer the first service for free and that is a good chance to take advantage and cut back on some of the costs. During the inspections, they will sturdy different parts of your building to find out where the weaknesses are.

  • Outside and inside - The exterior and interior both are going to be examined by the structural engineer. Everything looking weak, unsound or disrepair, they will be scrutinized. The inspector should remove the inside stucco to know if there is any damaged area of the building’s frame.

  • Crawl space and basement - In case you have a basement or any crawl space in your house, the inspector will check them too. Things they may look for could include signs of water damage that can weaken the structure of the buildings, water control systems or the drainage, as well as all the areas that may be prone to flooding.

  • Foundation - of course, the foundation is one of the most important areas of any building. Foundation also is the one area that often shows the most obvious signs of seismic damages.

  • Framing - next to the foundation, framing is also one of the most important places to be examined, which shows signs of possible instability. A framing lines up with the building foundation to maintain structural integrity.

  • Roof inspection - The last most important part of the inspection is the roof. The structural engineer will check the conditions of the gutters, roof surfaces, leaks and so on.

First Consultation

After the inspection is done, an engineer will write up a detailed report. This report should involve a list of the areas that are at risk of being collapsed during seismic activity, an estimate of the cost, options for different methods to retrofit your buildings, a detailed plan of the work that needs to be performed and a timeframe for how long will last the job. A phone call will be sent to schedule the first consultation once all this information has been put together. During this action, you will need to choose whether you want to hire them for the job or not.

Necessary Permits

Before any construction begins, you should be issued a building permit by the city and during the process, you will need to fill out an application and pay any required fees. The application needs to include a work plan so a city official can be sure that the works meet the present Los Angeles earthquake retrofitting codes. However, do not let this step overwhelm you. If you hire the right company, they will handle all of this for you.
You will also need to file the Tenant Habitability Plan with the Department of Housing, in case you are a landlord. This can be done online and this is approved within five business days, in general. The law states that you must give your tenants a 25-day notice, telling them of the work that is going to be done to the building. After this, they will be allowed to make other arrangements and ask any questions they could have. Your building permit will not be issued if this step is skipped. If the city for modification has not sent the work plan back, it can take about 38 days to get the permits.

Construction Works

It always depends on some factors, how much will be needed for the retrofitting works to be done and how long will take the process. These may include, how much does the building weighs, the highest hypothetical magnitude that fault line can experience. The three factors will also allow you to determine what method is the best for your seismic retrofit.

concrete shear walls used in retrofitting

These three methods are used in all retrofitting projects:

  • Special Moment Frames - these frames are considered to be the best solution for most earthquake retrofits. They come in a variety of sizes and can be delivered already assembled or flat shipped.

  • Shear Walls - The shear walls are used for strengthening the whole building and keep it from swaying during an earthquake. Adding shear walls is considered the most affordable solution when it comes to retrofitting. During a seismic activity, the walls can move laterally, and if the shaking force is strong, the building can separate from the foundation.

  • Steel Cantilever Column System - the cantilever I-beams quickly become the most used soft-story system for retrofitting. They are often more affordable than adding shear walls, for example, or special moment frames. L-beams are not suitable for all buildings and cantilever beams are best used to retrofit smaller buildings that have narrow areas.

City Inspections

Just as all the work is done it will need to be inspected by a city official. Again, the step should be taken care of by the retrofitting company you hired. Then a city engineer will come out to your property and check to make sure that the work which is done for your building matched the work plan on file. Once everything is found out to be done up to code you will be issued a Certificate of Completion.