New LED Streetlights at the corner of Ygnacio Blvd. and Montego, Walnut Creek, CA

Driving home tonight I noticed LED streetlights emitting a soft white glow over parts of Ygnacio Blvd, here in Walnut Creek.  As of this evening the lights only extend the 3/4 mile stretch between N. Civic Dr. and Marchbanks Dr. and a couple random streetlights West of N. Civic Dr. and East of North Broadway.  Three quarters of a mile is not much considering Ygnacio Blvd. is over 7 miles long and is only one of several major streets in the city.

The lights emit a very natural cool white as opposed to the amber tint cast by the current high pressure sodium lights that are located throughout the rest of the city.  The benefits of LED are incredibly low energy consumption and a ridiculously long life time; 75,000+ hours compared to the 12,000 to 24,000 hours of high pressure sodium or 1,000 hours of an incandescent bulb.  However, due to the fact that they emit a white light, and therefore a broader spectrum of wavelengths, they do result in more light pollution.

Walnut Creek already has a policy in place to replace all of the traffic signals with LED lights (walnut-creek.org: Signals – LEDs and Battery Backup), however I found no mention on the cities web page of any plans to replace the streetlights.  The city already spent $1.46 million of Federal Stimulus dollars to resurface 1 mile of Civic Drive and it apparently gets an additional $677,000 for energy efficiency and conservation projects (Contra Costa Times 4/24/2009: Walnut Creek gets slice of stimulus pie).  Replacing streetlights with LEDs has been a popular use of stimulus money.  San Jose, Milwakee, and Missouri City, Texas are among the cities doing so (USA Today 3/3/2009: More cities tap stimulus package for LED streetlights).  Recovery.gov lists a few projects for Walnut Creek, including a contract for $58,615 with One Line Power Systems, Inc.  The company, located in Walnut Creek, has no website and I was unable to find any information about what the company does.

It is unclear at this time whether the US taxpayer is opening their wallet for our new street lights, but I for one, am happy for the new light being cast on our city.

UPDATE:  January 8th, 2010

As of today the city has replaced 126 fixtures stretching nearly two miles from Oakland Boulevard to Marchbanks Drive.

Almost two months after they were installed the Contra Costa Times finally reported yesterday that the city of Walnut Creek paid $87,000 for the install after receiving a $17,950 rebate from PG&E.   A PG&E spokesman said they were able to offer the rebate because of stimulus funding.  It also appears that PG&E hired the contractor to install the lights.

According to the Contra Costa Times the city’s energy savings have been dramatic.  The city is paying $726 $7,230 per month to power the new fixtures, down from $14,080 a month.  Energy usage decreased to 5,700 kwh, less than half the energy the original fixtures used.

UPDATE:  January 22nd, 2010

Thanks to grandcanyondave for providing a link to PGE’s current rate structure.  This give us a little more insight into the cost savings of switching to LED lights.  The following numbers show a typical scenario similar to what the city may have been paying previously and currently.

According to PGE’s current rates:

126 HPS 250 watt fixtures x $0.567 x 200 hours/month = $14,288/month

126 LED 150 watt fixtures x $0.295 x 200 hours/month = $7,434/month

According to grandcanyondave the city previously had a mix of 125 and 250 High Pressure Sodium fixtures, and 200 hours/month is a little low if it is late in the year, however I think these numbers help give an idea of the cost associated with street lighting.

This short drive and the recent building collapse of the residential block in China made me reflect again on the very serious nature of the Architecture and building professions.  As Architects, engineers, contractors, designers, and draftsmen, the decisions and the work that we do have very serious real world consequences.

Not all problems result in loss of life, but sometimes the costs can be unimaginable.  Over the years I have seen many, many bad designs and construction mistakes, as has anyone who has worked in the profession for any amount of time.  I’ve seen structures sliding down hills, doors that don’t open, and shoddy and dangerous construction in abundance.  In order to protect the innocent I won’t be posting any of those problems here, but I’ll more than gladly share other people’s mistakes.

Below I have compiled some serious and not so serious building errors for your reflection.

Tacoma Narrows Bridge, June 27, 2009

The Tacoma  Narrows Bridge collapsed on Nov. 7th, 1940 only four months after completion.  The only casualty was a dog stuck in a car on the bridge when it collapsed.

This unoccupied 13 story residential building collapsed while still under construction, apparently from over excavating the foundation while constructing a parking garage coupled with heavy rain.  Amazingly only one casualty was reported.  (Chinese news article | English translation)

13 story Shanghai building collapses, June 27th, 2009.

Improper excavation and rain apparently led to the buildings collapse

The 1942 Cocoanut Grove fire in Boston killed 492 people and resulted in sweeping building and fire code reform. The filled over capacity club, highly flammable decorations, and a poorly designed and modified egress system resulted in this tragedy. Today designers must follow strict laws regarding the sizing, construction, and placement of a buildings doors, stars, and corridors.

Cocoanut Grove memorial, dedicated in 1993

Poor rooftop access in Arizona, Jan. 20, 2008.  Unfortunately, the little details like service access are often overlooked by Architects and building inspectors alike.

On May 23, 2004, a 33 foot section of the Charles-de-Gaulle Airport terminal in France collapsed killing four people and injuring 3, just 11 months after going into service.  The main cause of the failure was determined to be poor detailing between the building facade and the structure.

Charles-de-Gaulle Airport Terminal 2E

While MIT’s Sata Center is heralded by some as architectural genius, MIT sued the architect, Frank Gehry, on Oct. 31, 2007 in response to leaks, cracked masonry, mold growth, and drainage and ice build up problems.   As of the date of this article the lawsuit is still pending.  The architect claims the owner value engineered the roof which resulted in the problems, and MIT claims the architect provided “deficient design services and drawings.”

Ray and Maria Stata Center, MIT, June 2006

The 362,987 square foot building features an underground public parking lot, hundreds of computers, an auditorium, and “the book spiral” that allows visitors to traverse the entire book collection all on one continuous “floor” that spirals over 5 stories.  I found the entire structure to be amazing in both form and function.  Practical details like having floor air registers and waterless urinals are complimented by having text embossed flooring, and vertical circulation identified with a consistent bright yellow.

During my visits on June 27th and 28th I overheard an elderly woman comment that being in the building was giving her an anxiety attack.  I would agree that the building as a whole can seem a bit overwhelming, it is very different from the traditional library.  However, I found the building to be exciting and invigorating.  The building draws you to explore it and discover.  I think libraries as a whole can be very compartmentalized, but the spaces in Seattle Central Library were very connected not just horizontally but vertically as well.  I was also surprised by the numerous intimate areas that were created on balconies, and in glazed niches.  There were many places that I could see myself sitting for hours just reading.

Overall I found the building very impressive.

(Photo essay after the break)

Multi Story Building with Curves! Ciudad Real, Spain

There are a number of typical things being done in this building.   As is the case with most Spanish multi-story buildings, a series of concrete columns and beams are spanned with concrete joists and brick units to create the structure for concrete floor decks.

Also typical are the crane on site during the entire construction process as well as the safety netting around the building.

I like this picture because it shows how flexible this system can be.  Unlike the building I showed earlier the upper floors introduce some curves.

Chalet Factory, Azuqueca de Henares, Spain

The above photo was a very common site during my time in Spain.  The townhouse, or Chalet, was becoming very poplar and the construction industry was responding by building hundreds of these units.  These structure use load bearing brick walls as opposed to the concrete column and beam structures of the 3+ story buildings.

This last picture is a close up of the entry stair construction at another development.

Typical exterior stair construction, Azuqueca de Henares, Spain

I think we see a couple of interesting in this picture.

Firstly, the stair.  The structure for the stair is a simple concrete ramp.  The concrete is poured without forming any treads.  The reads and risers are created from hollow bricks and mortared together.  The stairs will be finished with tiles.

Secondly, we see the windows and doors in various phases of installation.  Because the entire structure is concrete and masonry there is no counter flashing for the windows and doors.  The exterior finishes are installed and then the windows are set in place.  This is very different from the complex system of flashing and counter-flashing used in framed construction here in the United States.

The formwork has been removed from the 1st floor columns and the forms are being set up for the second floor. It was only a couple days since the first floor columns were poured but they won't be supporting any load for a few more. Metal jacks are setup steel joists and wood formwork are laid out.

With the wood forms in place concrete joists are laid down and hollow brick units are laid down on top of them. In a little over a day the entire floor is laid out. The joists and bricks are simply laid in place are not anchored in any way.

Following adding perimeter formwork, rebar, and welded wire mesh, the first floor is poured. The crane is used to transfer the concrete from the truck to the workers. All of the beams and columns are vibrated and then the floor is leveled. The finish is left rather rough as the entire floor surface will eventually be tiled.

Here is a better shot of the floor beam rebar and formwork. No formwork is setup against the two adjacent buildings. A one inch piece of foam will be set against the building before the floor is poured. An edge form is set up around the elevator shaft and the building perimeter.

A finished floor slab.

One month after finishing the foundation the formwork is nearly finished for the 4th and final floor of the building. All of the steel jacks are still in place for the entire building. The neighbors will soon loose the views out of their bathroom windows.

The hopper make another trip up to the fourth floor. This floor feature a larger cantilever on the corner and has more rebar than the other floors.

Within 5 days the floor has cured and the final columns have been formed, poured, and had their formwork removed.

The roof is formed the same way as the floors. The columns were poured at varying heights and the rebar will tie into the roof beams. The same system of concrete joists and hollow bricks will be used.

The roof is poured in place.

With all of the structural work complete the crew begins to clean up the site. The jacks are removed from the bottom floors and the concrete beams bear the weight of the building for the first time.

I unfortunately moved away from Guadalajara on August 14th so I missed the application of the building finishes, however I did return to take a photo of the completed building about 8 months later. If this building were typical, which I believe it is, the walls were made of a lightweight hollow brick, plaster would be applied to the interior face and a decorative brick veneer to the exterior. The roof tiles are applied directly to the concrete roof deck.

Persian blinds are standard in Spain and are something I missed coming back to the States. They are so convenient and do a great job with light control. Notice the temporary brick wall on the first floor this will eventually be replaced with ground floor retail.

I lived for 9 months in Guadalajara, the capitol city of the province of Guadalajara, located about 37 miles ENE of Madrid.  Although some of the structures in the city date back to the 8th century most the city is relatively new, constructed in the last 60 years.  With the addition of the AVE (high speed train) stop in 2003 the city has seen an explosion of growth.

I lived in Guadalajara in the pre-AVE days on the 7th floor of the 10 story building in center of the photo below.  6 months after arriving I awoke on May 27th, 2000 to see that the small house directly across the street was being demolished.  I whipped out my camera and shot construction progress photos for the next 3 months.  The building is located on the  North East corner of Avenida de Castilla and Calle Alvargomez de Ciudad Real, one block West of Calle de Toledo.

Birdseye View of Finished Building in center of photo, via Live Maps on 5/21/09.

The following photos chronicle the construction of the structural shell of the building.  I have added my thoughts on the methods of construction that were the norm for my time in Spain.  I pulled these pictures from my photo album and the notes I made 9 years ago are unfortunately glued to the pictures.

The demolition began around 8am on May 27th, 2000. Piso is Spanish for floor, or apartment. These pictures were all taken from my bedroom window.

It was a shame to see all of this Spanish tile be destroyed like this. Authentic Spanish tile is something we pay high prices for in the United States.

Demolition goes quickly. I found it interesting that this demolished building was constructed with the same materials that the new building will be built with. This building would use solid bricks where the new building would be constructed with hollow lightweight brick units.

After about 6 hours of work, remember the two hour 'medio dia' or 'siesta' break, the house was gone including all of the foundation.

The lot stood for over a week in this state. The old building appears as a ghost like silhouette.

I knew the knew building was to be bigger than the original for a number of reasons. For one, the foundation excavations are much more significant, also, the footprint of the building consumes the entire lot, not a portion as the old structure did. Note on this side of the street the large concrete blocks placed in the street for the crane.

The crane was offloaded from the truck and erected on site. It will stay on site throughout the entire construction process. Rebar cages were placed in the excavations and the footings are poured in place. No form work was used.

All of the foundations are spread footings and grade beams. I found it interesting that they pouted the perimeter spread footings then excavated the grade beams and footings.

One week after the footings were poured they began to form the first floor columns. With every pour they conducted a slump test and poured concrete cylinders for strength testing. They always did the tests near the crane so I had a good view. Note that the first floor walls are already being laid. It's hard to see in this photo but the bricks are hollow. The mason never used a saw but simply used his trowel to chop the bricks to size.

Tomorrow I will post the photos of the remainder of the construction.

Two years ago I was on the Cal Poly San Luis Obispo campus representing my firm at a job fair and I walked across campus with the sole purpose of taking photos of the then almost completed Engineerning IV building.

Although this happened a while ago I though I would post these pictures because you will notice that this building is currently featured as the banner for this website.

This building is very different in style from the other buildings on campus, but is consistent with the metel and paneled facades of the new engineering complex on this side of campus. 

What do you think?