Building laws for hillside properties have changed drastically since the 1994 Northridge earthquake. Our office was involved in over 400 home structural inspections and helped the local Building and Safety departments to craft new “Hillside Ordinances” to avoid the most common hillside construction problems. There are several related new building laws, but I think the most important is the H/3 rule. This rule requires the foundation of a new construction, or remodeling of an old one, on a hillside to be of a minimum depth, without consideration of the underlying soil characteristic, based on the height of the existing slope only. Without going into the technical details, foundations on hillsides, without exception, have to be on deep piles – sometimes 40, 50 or even 60 feet deep.
Recently our office faced the unpleasant task of explaining to a few new home owners that their proposed addition on their recently purchased hillside property would be much more expensive than they thought at the time of the purchase of the property, because of this H/3 rule.
My advice is to consult a soil engineer, or structural engineering company, or have an approved, recent soil report included in the contingencies of the purchase.
Re-posted from our newsletter on 10/16/2013
“I remember in my younger years, before I became an engineer that a bridge was built over the Danube in Budapest. It was a suspension bridge and slowly but surely the pieces came together hanging from the suspension cables and the bridge was finished. Before it was given to the public for use, a test loading had to be done. One by one trucks fully loaded with sand, buses, street cars and all kind of heavy equipment rolled on to the bridge. The sight was awesome. The bridge was deflecting, stretching, bending to the limit. But the sight what I’ll never forget was this. The chief design engineer of the bridge was under the bridge alone, moored in a tiny dinghy on the water, showing the whole world that his is putting his life on the line for his design. Now that’s what I call responsibility. It started with the first known building law, Hammurabi’s law about 5,000 years ago which stated: “If a building collapses and the owner’s son dies, the builder’s son must be put to death”. Serious stuff…”
Re-posted from our newsletter on 12/12/2013
Engineers think that if it ain’t broke, it doesn’t have enough features yet.
Last month, I participated in a think-tank meeting for seismic related issues in the Los Angeles area. Among other things — like geology, seismic preparedness, seismic faults, etc. — the soft story issue came up as one of the most pressing items for structural engineers recently. One of the panelists was Lucy Jones from USGS, who was recently hired or “loaned” to the city of Los Angeles to help the city put together a list of under reinforced concrete high-rise and “soft story” buildings. You could see her on TV rather frequently answering questions about the recent La Brea earthquake. She is known as the Earthquake Lady.
There were suggestions for mandatory upgrades by new city, county or even state ordinances, state bonds to finance construction — because actually this is more of a state, than city problem — tax incentives for landlords, etc. All of these have been discussed before, but one suggestion stood out and it wasn’t mine. Dog gone it!
For departments of public health, health inspectors go to restaurants and grade them for cleanness and other health related issues. The restaurants get an A, B or C and those placards have to be posted at the entry of the restaurants with big blue letters. Restaurant owners were so much against it at the beginning, fearing a loss of customers. Today it is a normal thing to check out a restaurant’s grade. I know that I wouldn’t eat in a restaurant with a C rating. The bottom line is that restaurants really got much cleaner since this system came into law.
Why not to do a similar action for apartment buildings? Apartment owners and landlords are already paying a yearly fee for inspectors to check out the apartments for health and other issues. It would be simple: make landlords post a sign issued by the local Building and Safety inspectors on the front elevation of the building indicating that this building is a dangerous place to live in. This would be a tremendous incentive for landlords to upgrade their buildings in fear of losing tenants.
No mandatory upgrade, no political issues, no deadlines, it would be voluntary only.
Problem solved, and in a few years the majority of soft story buildings would be fixed.
The biggest questions is, of course, why didn’t I think of that?!
What do you think? I’d love to hear your thoughts on this.
In light of the recent earthquakes I thought that sharing a few lesser known facts will help to understand what earthquakes are actually all about.
The earthquakes of California are caused by the movement of huge blocks, or plates, of the earth’s crust – the Pacific and North American plates. The Pacific plate is moving northwest, scraping horizontally past the North American plate at a rate of about 2 inches per year, which is about the rate your fingernails grow. (This maybe explains why my wife has to go to the manicurist so many times a year.:))