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China’s Air Pollution Problem

March 8th, 2013 by

The following post is authored by student and Sherwood blogging intern, Rachel Gross.

One of the most talked about environmental topics in 2013 has been the horrific air quality in Beijing, China. In January, the city’s air reached a level of 755 on the U.S. EPA’s Air Quality Index, which is only supposed to go up to 500. To understand just how bad this is, anything above 151 is considered unhealthy. The 301 to 500 range is considered “hazardous” and an “emergency condition” in which the entire population in the area may experience serious health effects.

The Air Quality Index measures the amount of PM2.5 (particulate matter less than 2.5 micrometers in diameter) in the air. Recent reports show that the air quality in Beijing generally varies between 250 and 400 and is almost constantly considered either “very unhealthy” or “hazardous”. Clearly the city’s air pollution is a long-term issue. The picture below shows just how bad the air quality can be on a particularly bad day.

Chinese air quality has been notoriously poor since the country tends to emphasize economic growth through industrialization and manufacturing over environmental protection. The increased amount of car use and pollution from power plants is thought to have caused the majority of the air pollution that plagues China’s cities.

Severe air pollution can result in serious health issues such as respiratory infections like bronchitis and pneumonia. Long-term exposure to poor air quality can lead to chronic respiratory disease, lung cancer, and heart disease. Because of these health effects, the air quality in China became an international concern during the 2008 Olympics. A lot of athletes were concerned that their performance and personal health would be adversely affected during the competition because of the polluted air. During the months leading up to the Olympics, the Chinese government instituted several regulations that limited that amount of vehicular traffic in and around Beijing to reduce pollutant emissions.

To improve its air quality, China will impose stricter emission regulations on coal-fired power plants as well as major manufacturing plants. These regulations seem to be a knee-jerk reaction to the international media buzz about the recent air quality reports and it remains to be seen how effective these measures will be.  The Chinese national government and individual Chinese cities will have to do much more to effectively decrease air pollution to a safe level. Ultimately, China faces the same challenge as the rest of the world in reducing its dependence on harmful fossil fuels. This must be done through changes in transportation infrastructure as well as sustainable urban planning and development.

Sherwood has worked on a number projects in China aimed at sustainable development. In my last blog post, I mentioned Sherwood’s involvement with Tianjin Eco-City. This project worked to improve air quality by relying on renewable (and non-polluting) energy resources and an urban layout that encourages walking and biking instead of driving. Another project, the Baietan Area Master Plan in Guangzhou, is a similar sustainable urban planning project on a larger scale. This project aims to transform industrialized and polluted land into a clean, ecologically designed community. The area will reduce energy demand by implementing building-scale energy efficiency measures and smart-grid technology. Energy for the city will be provided from a new nuclear power plant. Sherwood has participated in several such sustainable urban design projects in the Chinese cities of Jiaxing, Lanfang, and Wenzhou. Many of these projects aim to achieve Net Zero energy use. By decreasing energy demand and utilizing renewable energy resources, China can progress toward a cleaner, healthier, and more sustainable future.

Masdar: A Green City Case Study

February 22nd, 2013 by

The following post is authored by student and Sherwood blogging intern, Rachel Gross.

One of my professors recently asked our class to think about what “grand challenges” face our society, and my mind immediately jumped to population growth and urbanization. As population continues to grow over the next several decades, resources will become more scarce and human impact on the environment will also grow. UN population studies project that world population will reach 9.31 billion by 2050. Where will these people live? Current and projected urbanization rates estimate that by 2050, about 6.25 billion people (67% of the total world population) will live in cities. This is almost twice the 2010 urban population of 3.56 billion people (about 52% of the current world population).

Cities are a huge source of anthropogenic impact on the environment. The large concentration of people in a city leads to increased air and water pollution, energy consumption, and biodiversity loss. Although cities contain half of the world’s population, they consume 60-80% of the world’s annual energy use and contribute to 75% of the world’s anthropogenic carbon dioxide emission. As cities continue to grow with population, so too will their impact on the environment. However, this impact can be mitigated through careful city planning and the creation of “green cities”. I discovered one such city during a summer internship several years ago. I was working at CH2M Hill and I got to hear a presentation about one of their projects, Masdar City. Near Abu Dhabi in the United Arab Emirates, Masdar City is a low carbon, low waste planned community of 40,000 that is going to be completed in 2025.

An artists’ rendering of the completed Masdar City.
Photo Credit: http://masdarcity.ae/

Masdar City was established in 2006 with the aim of becoming a world leader in renewable energy and an example of a commercially viable, sustainable city. Currently, the city consists of just 300 residents and several buildings: the Masdar Institute of Science and Technology, residences for the Institute, and some food, service, and retail outlets. All of these buildings are powered by an on-site 10 MW photovoltaic solar plant. This 22 hectare plant is the largest solar plant in the Middle East. The city will also draw on geothermal and wind energy. When the city is complete, 20% of Masdar’s energy will come from on-site renewable resources and the rest will come from renewable energy resources elsewhere in the UAE.

Masdar’s 45m wind tower.
Photo credit: http://masdarcity.ae/

In addition to exclusively using renewable resources for energy, all of the buildings and the entire city itself have been designed to maximize energy efficiency. The buildings constructed in the city must adhere to strict energy-minimizing guidelines with regard to insulation, lighting, windows, smart appliances and energy meters. The city itself is oriented on a southeast-northwest axis to minimize heat gain and maximize cooling shade and breezes. The streets are fairly narrow to supply more shade from the buildings, and various water and greenery installations provide additional cooling. One of the most interesting innovations in cooling is the city’s wind tower. This 45m tower captures upper-level winds and directs them down onto the street below. The top of the tower has sensors that control the shutters that open toward the prevailing wind and close in the opposite direction to push the wind downwards. This wind tower is a high-tech version of traditional Persian “windcatchers” that date back to the 17th century. There are also windgates throughout the city to direct and regulate the flow of air on the streets. Overall, the streets of Masdar City are 15-20 °C cooler than the streets of Abu Dhabi, which is only about 10 miles away.

Masdar City’s transportation infrastructure is perhaps the largest departure from a traditional city because there are to be no petroleum-based cars in the city. The city is designed for pedestrians, with many shaded walkways. However, there will be several forms of public transportation. Right now, both electric vehicles and a personal rapid transit (PRT) system are being tested in a pilot program. The PRT system features small, fully-automated, electric “podcars” that hold two people. These podcars can travel up to 25 mph and are controlled by a sophisticated navigation system. The concept of personal rapid transit was incredible to me and I thought that Masdar City must be the first city to implement this idea. However, I found out that the PRT concept actually dates back to the 1960s and a PRT system was built in 1975 in Morgantown, West Virginia. While this concept never caught on in the 1970s, PRT is now being considered in different urban and community environments around the world. In 2010, Masdar City was the first to put a PRT system into operation, but London Heathrow airport now has PRT vehicles to take passengers to and from the parking lot and larger scale systems are being constructed in Suncheon, South Korea and Amritsar, India. Studies have shown that PRT vehicles use about a quarter of the energy per passenger per mile of a standard automobile.

Two person, fully automated, electric personal rapid transit (PRT) vehicle.
Photo credit: http://masdarcity.ae/

The city also takes water and waste management very seriously.  On a per person basis, Masdar City uses less than half of the water that an average city uses. This is achieved through the use of high efficiency appliances as well as smart meters that can detect leaks in water system. Additionally, 100% of the wastewater generated from the city is treated and reused in landscaping, which has led to huge water savings. Masdar City has also taken great efforts to manage its waste, with 96% of its construction waste reused in other ways to build the city. However, the city’s long-term landfill diversion goal is only 50%, which I thought was surprisingly low. If San Francisco can achieve 75% landfill diversion, shouldn’t a city built entirely to be green do even better?

While most people agree that Masdar City’s aims are admirable, there are some serious criticisms of the city. Originally, Masdar was marketed as a “zero-waste, carbon neutral” city, but it’s now claiming to be “low carbon” with only 50% landfill diversion. At Greenbuild, I met a sustainability consultant for Masdar City who said that he was very disappointed with how much the actual city is deviating from its original sustainable goals. He was also dissatisfied with the actual construction progress. The city was originally supposed to be completed in 2016, but that completion date has been pushed back by almost 10 years.

Despite the criticisms, I think that Masdar City represents an important step in the right direction in sustainable urban development. It is definitely on the cutting-edge of sustainability, and I look forward to seeing more cities around the world follow its lead. Masdar City is one of several green cities to start construction within the last 10 years. Other notable examples are PlanIT Valley in Portugal and Tianjin Eco-City in China. Sherwood has worked in Tianjin Eco-City, performing green infrastructure and sustainable site design services for a 350 unit residential community in the city.  This project focused on water conservation and reuse due to the heavily depleted aquifer and saline soils in this area. The $10 billion eco-city is expected to be completed in 2020.

View of the start up area of Tianjin Eco-City.
Photo credit: http://www.tianjinecocity.gov.sg/gal_2012.htm

For more information, click here for Masdar City and here for Tianjin Eco-City.

The New Packard Foundation Headquarters

November 30th, 2012 by

Photo © Jeremy Bittermann

Working on a team with lead architect EHDDTipping Mar and Integral Group Sherwood helped to design the new headquarters of the David and Lucile Packard Foundation, which sits in downtown Los Altos, California. Sherwood worked with the team to design multiple sustainable systems, including rainwater harvesting, green streets, stormwater infiltration and treatment, and pedestrian-friendly circulation. Sherwood was also responsible for sustainable systems integration, grading and drainage design, site utility design, and deconstruction all the way through construction. As part of this project, a 550-foot length of public street was redesigned to include rain gardens adjacent to the street that will treat road runoff, and four surface parking lots were retrofitted with vegetated swales and infiltration basins to treat stormwater runoff.

The new headquarters building is designed for net-zero energy consumption and LEED Platinum certification, and uses a diverse set of materials including reclaimed redwood, FSC-certified cedar and recycled copper. In two 250-foot long office pavilions and 50,00 square feet of space, the building provides a combination of private offices, open work areas, communal gathering spaces and conference rooms.

Photo © Jeremy Bittermann

The innovative green design of the new headquarters also extends to lighting and energy use. Windows and skylights on the northwest and southwest walls provide ample daylight. The design also includes automated interior and exterior blinds rise and fall with the movement of the sun to not only provide shade when needed, but also to help regulate the temperature within the building. Energy use is being addressed via reduced plug loads and PV production from PV panels located on-site. Employees will not have personal printers nor be allowed to have personal heaters at their desks, which will help reduce the plug loads. Through monitoring data that has been collected since the building opened to the employees, it has been shown that energy use is even lower than originally predicted. This reduction in energy use is on top of the designed annual use of 17% less energy than the 273,000 kilowatt-hours generated by the PV panels.

Photo © Jeremy Bittermann

Finally, through design by Tipping Mar, the building is seismic-braced to a level that exceeds the state building code requirements. Steven Tipping, the firm’s president explains, “The California building code is much more about ‘life safety’ than preserving the building. We tried to come up with a building that was life-safe and minimized damage to the building during ‘the Big One’ “.

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Click here to watch a time-lapse video of the entire construction process.

To learn more about the building, visit the Packard Foundation website.

To read the full article from GreenSource, click here

Flushed with Pride

November 14th, 2012 by

In The Economist’s September issue, “Flushed with pride” highlights the work that the Bill & Melinda Gates Foundation is doing to bring safe, affordable toilets to the 40% of the world’s population that lacks access to basic sanitation.  “Each year, 1.5 million children die from diarrhea. Better toilets could reduce the death toll.” (Flushed). The Foundation’s mission aligns with more than one of the UN’s Millennium Development Goals. MDG #4 seeks to reduce child mortality, and though the number of child deaths is falling, poor sanitation is still al leading contributor to child death rates today. MDG #7 aims to halve the proportion of the population without sustainable access to safe drinking water and basic sanitation.

The winning design. Image via ScienceMag.org

The Gates Foundation held a contest called “Reinventing the Toilet Challenge”, and on August 14th, they chose their winner, Michael Hoffman of the California Institute of Technology. Using solar panels to power an electrochemical system, the winning toilet converts waste into useful components. “One is a compound which oxidises the salts in urine to generate chlorine. This creates a mildly disinfecting solution that can be used to flush the toilet. The second is hydrogen, which is suitable for cooking or for powering a fuel cell to produce electricity. The residue from the process can be used as fertiliser.” (Flushed).  Hoffman’s toilet design is not only innovative, but it is on track to achieve the extremely ambitious criteria set by the Gate Foundation, which are listed below:

- Costs less than 5 cents per user per day to operate

- Does not require a clean water supply

- Does not require sewage infrastructure to transport the waste

- Will generate energy and recover salts, water & other nutrients

Though openly discussing toilets is definitely far from popular, it is important that human sanitation is addressed. The Gates Foundation has devoted $6.5 million (out of the $3 billion they spend on projects each year) to the “Reinventing the Toilet Challenge” project and they plan to spend up to $80 million a year on sanitation. This “sustainable loo” is a step in the right direction to improving sanitation in the developing word.

 

Click here for more information on the Millennium Development Goals.

Read the full article “Flushed with Pride”.

Sherwood @ Greenbuild 2012

November 13th, 2012 by

Please join us Wednesday, November 14th for our Greenbuild happy hour and art opening at Sherwood!

The night will feature specialty cocktails, entertainment, art, food, and craft beer on tap featuring a never-before-seen Gigante IPA, in honor of the San Francisco Giants’ World Series victory (colored appropriately).

Wednesday, November 14th 

6:00 – 9:00pm
58 Maiden Lane, Third Floor
San Francisco, CA 94108

Please RSVP to Wendy, at whii@sherwoodengineers.com

In honor of the Greenbuild International Expo in San Francisco this year, Sherwood Design Engineers and Sherwood Gallery are pleased to announce an exhibition of selected works by San Francisco based artist John Roloff. The exhibition titled, The Sea Within the Sea consists of video documentation and photographic work. In the selected works, Sherwood strives to portray environmental change in geologic time, and the interpretation of these processes through the lens of human and urban development. John Roloff depicts the intersection between science, art, nature and culture; and observes with great curiosity and amazement nature’s relationship to everything else.

John Roloff is a visual artist who works conceptually with site, process and natural systems. He is known primarily for his outdoor kiln/furnace projects done from the late 1970’s to the early 1990’s as well as other large-scale environmental and gallery installations investigating geologic and natural phenomena. He studied geology at UC Davis, Davis, CA with Professor Eldridge Moores and others during the formative days of plate tectonics in the mid-1960’s. Subsequently, he studied art with Bob Arneson and William T. Wiley also at UC Davis in the late 1960’s. In addition to numerous environmental, site-specific installations in the US, Canada and Europe, his work has been included in exhibitions at the Whitney Museum of American Art, UC Berkeley Museum, San Francisco Museum of Modern Art, Smithsonian Institution, Photoscene Cologne and the Venice Architectural and Art Biennales. He has received 3 artists visual arts fellowships from the NEA, a Guggenheim Foundation fellowship and a California Arts Council grant for visual artists. He is represented by the Lance Fung Gallery in NY and Gallery Paule Anglim in San Francisco. He is currently a Professor of Sculpture at the San Francisco Art Institute.

 

Sherwood Institute’s Michel St. Pierre published in Stanford’s Social Innovation Review

November 8th, 2012 by

Residents along the edge of the polluted Banthur Lake, Bangalore.

On October 16th, Sherwood Institute board member Michel St. Pierre published an article titled “Sustainable Development in India” in the Stanford Social Innovation Review in which he discusses the work the Sherwood Institute’s work in Bangalore, and how the city has been affected by India’s quickly rising population. “Bangalore… is a metropolis of 5.4 million people that was once dotted with hundreds of lakes, which created a livable city providing food and water for residents, opportunities for livelihoods, habitat for rare and migratory birds, and a rich cultural heritage” Pierre describes. “With the city’s rapid development, and a lack of public action to protect the natural resources of the city, today less than a third of the lakes remain. There is pollution from human and industrial waste and land filling has occurred through illegal dumping and development.” Sherwood Institute’s project to restore the lakes of Bangalore encourages innovation, as a solution must integrate many aspects of the city’s infrastructure, ecological and social systems. “The solution includes efforts in a variety of areas: from garnering local political support and creating a Lake Development Advisory Commission, to working to affect policy in Bangalore and fundraising for early phase restoration efforts.” Pierre “believe[s] that the vision for the lake restoration is a key step toward a major quality of urban life enhancement in Bangalore… Hopefully, this initiative can provide a way forward for similar initiatives elsewhere in the country.”

This month, St. Pierre will be presenting with Sherwood Institute Associate Director John Leys at the Greenbuild International Conference and Expo in San Francisco on the topic. The talk will take place on November 15th from 1:30-2:30pm. Details here. (link to GB site session info)

Click here to read the full article.

Trash floats in a lake in Bangalore.

A polluted lake in Bangalore.

The Living Machine® at SFPUC

August 3rd, 2012 by

This morning, a group of Sherwood engineers were given a tour of the Living Machine® wastewater treatment system at the new headquarters of the San Francisco Public Utilities Commission (SFPUC). The new headquarters building is a model of innovation and sustainable design, from its energy efficiency, to water reuse, to ecological and environmental benefits. Living Machine® Technology treats and reuses wastewater by incorporating plants and beneficial bacteria with innovative engineering. Based on the principles of wetland ecology, the tidal process cleans water, making the Living Machine® extremely energy-efficient and allowing the system to produce reclaimed water that meets high-quality reuse standards.

Group Photo

Our engineers in the public café, in front of a section of the Living Machine®.

This was a unique project, according to Scott Nelles the Living Machine® Director of Sales, because the SFPUC acted as the owner, the financer, and the regulator for the project. In a building that houses around 950 employees, they consume 60% less water than other similarly-sized buildings.  The SFPUC will save approximately 750,000 gallons of water per year by using the reclaimed water for on-site irrigation and for water to flush toilets.

The system in the SFPUC HQ is slightly different than the typical Living Machine®. In the first step, the mixed grey and black water flows into a primary tank, where solids settle and can be flushed directly to the sewer. The water then moves into a separate equalization tank, before moving into Stage 1 of the wetland treatment.  Stage 1 accelerates the tidal wetland cycle to 12-16 times a day, with Cells A & B alternating between full/empty. The aggregate media-filled planters promote the development of micro-ecosystems, which efficiently remove nutrients and solids from the wastewater, allowing the plants above to thrive.

Stage 1 Planter

This planter on the Golden Gate Avenue side, contains cells A & B of the Stage 1 tidal flow wetland treatment. Though Stage 1 treats the rawest wastewater, the planter has no negative odor!

The water then moves onto Stage 2, where at the SFPUC it is treated through trickle-down filtration, in 3 different cells. Because the water is much cleaner in the second stage, different plants are able to grow, allowing for greater ecological diversity. Even if a pest infests a certain species of plant, the rest are likely to remain untouched.

Stage 2 Cells

Cell C of Stage 2 resides both inside and outside the café (left) while Cells A & B sit along Polk Street (right) . The plants will grow to be much larger; these were only planted in mid June.

The water is then transported to the Polishing stage, in which it is cleaned for reuse. At the SFPUC, the water undergoes both UV and chlorine treatment to ensure that it can be sanitarily reused for both irrigation and toilet flushing. The utility room also held the touch-screen controls and monitors for the entire system. Click here to view an animation of the typical Living Machine® process.

Living Machine Controls

Above is the touch-screen control panel, detailing the processes and current statuses of each of the 6 stages of the system (primary, stage 1, stage 2, polishing, reuse & rainwater capture).

Click here to learn more about other sustainability features of the new SFPUC headquarters, or watch it in a video!

Bay Bridge Tour: Part 2

July 31st, 2012 by

Last week, we posted about some of the information our engineers gathered during their tour of the new San Francisco – Oakland Bay Bridge. Here is part two of our post, with more stories about the construction process.

Great care has been taken to help protect the environment in the planning and construction of the bridge. When driving up to the Yerba Buena Transition structure, there was a section of water near the island that was blocked off by buoys. These buoys designated a zone with eelgrass, a protected marine plant that provides food and shelter to many fish and other local species.  This shows just part of the great effort being made to conserve the environment around the bay bridge, even during construction.

The bay bridge is also home to the largest colony of double-crested Cormorants; these birds make their nests in the underside of the old east span. This means, that along with all of the other construction, special platforms have been added to the underside of the new bridge, so that the birds can make a new home once the old bridge has been taken down. These “cormorant condos” are an effort to protect this species of special concern, and cost around $550,000 to implement. You can read more about these structures and birds in this San Francisco Chronicle article.

Cormorant Condos

The thin platforms along the underside of the skyway are the “Cormorant Condos”.

As a final step in environmental protection, the old east span will be demolished in a different way. There will be no explosions or collapsing bridges, because the original east span was not only built with asbestos, but much of the paint contains lead, and it would be very damaging for those materials to end up in the water. So the old bridge will be cut down piece-by-piece, to ensure that it is disposed of properly, and to keep the environment safe.

One of the many challenges that the design faced was its proximity to historical landmarks and sites on Yerba Buena Island. For example, a torpedo warehouse from World War II is located under the transition structure, and the workers must take extra precautions when working there, being extra careful not to drop any tools, bolts etc. In order to help them remember, the falsework under the bridge is painted grey in that section. However, a real challenge came when it was discovered that the designed bridge would cast a shadow over Nimitz mansion, which belonged to respected admiral Chester W. Nimitz. This was considered disrespectful to the admiral and the historic site, and the Yerba Buena transition had to be shifted so that the mansion would remain always in the sun during the day.

Torpedo Warehouse

Falsework is painted grey overtop of a historical torpedo warehouse.

While touring the new bridge, there was also ample opportunity to examine the old east span as well. As part of the tour, a “secret” protective troll that is welded onto the bridge was pointed out. It stands on the replacement section of the upper deck; the original section fell during the 1989 Loma Prieta Earthquake. This troll was created by local artist Bill Roan and then welded by ironworkers, without permission, onto the replacement deck. Trolls are commonly known as protectors of bridges, and the industrial troll seems to have done its part since then to protect the east span. It is unclear what will happen to the troll after the demolition of the old east span.

Bay Bridge Troll

Image courtesy of Wikipedia.

We look forward to the opening of the Bay Bridge in the fall of 2013!

Click here to learn more about the San Francisco – Oakland Bay Bridge. 

Bay Bridge Tour: Part 1

July 27th, 2012 by

On July 24,  a few of our engineers attended an informational session and boat tour of the new east span of the San Francisco – Oakland Bay Bridge, hosted by CalTrans. The east span of the new Bay Bridge includes the Oakland touchdown, the skyway, the self-anchored suspension span and the Yerba Buena transition structure, and it is currently slated to open Labor Day weekend, 2013. Here are some of the facts and stories that stood out.

Group Photo

Our engineers, in front of the self-anchored suspension span.

The self-anchored suspension main cable is quite extraordinary. The cable is 2.6 feet in diameter, and stretches nearly 1-mile long. The cable is made up of 137 bundled “strands”, which are 2.5 inches in diameter. These strands are each comprised of 127 5mm wires, with more than 17,000 single, mile-long wires making up the entire main cable. Each of the 5mm wires is strong enough to hold a military-grade Hummer. Now that’s impressive.

Cable Cross Section

The sample cross section of the main suspension cable highlights the large number of strands by using different colors

Completing the deck of the suspension portion was a feat in itself. The deck is made out of 28 pre-fabricated sections that were brought to the site through the Panama canal. In order to then lift these sections up the “Left Coast Lifter”, a custom crane, was built and is the largest of its kind on the West Coast; the 1,900 ton shear leg crane holds a 328-foot boom, and it supported by a 400×100 foot barge.

Left Coast Lifter

The “Left Coast Lifter” moored in Oakland.

The bridge will also be a model for seismic safety innovation. The new span not only has a 150-year expected life, but it is designed for a 1500-year earthquake, making it one of the safest places to be in the event of another major earthquake in the Bay Area. The main tower is comprised of four legs that are connected by shear link beams, which allow all four legs to move independently. The shear link beams can bend and shift, keeping the structure upright and undamaged during an earthquake. There are also hinge pipe beams installed within the deck, which allow for six feet of lateral movement of the bridge (which is a phenomenal upgrade from the old bridge, which only allowed for four inches of movement). A final measure taken to withstand earthquakes is the battered piles under the skyway, which extend 300 feet into the ground for superior stability.

Check out a video simulation of the seismic innovations by clicking here.

 

Here are some very notable numbers that describe the new bridge:

  • 150,000 people have worked on the bridge thus far, from the engineers to the painters.
  • 270,000 cars cross the bridge daily, emphasizing the importance of the side-by-side construction of the new bridge, and the coordination required for the Oakland touchdown and the Yerba Buena transition structure.
  • The skyway, which makes up 1.2 miles of the 2.2 mile bridge, not only has 2 parallel viaducts that separate the 5-lane east and west-bound traffic, but each deck also includes 10 foot shoulders, that will help keep traffic moving in the event of an accident.
  • Combined, all of the skyway elements contain approximately 450,000 cubic yards of concrete, 120 million pounds of reinforcing steel and 200 million pounds of structural steel. The deck sections are the largest of their kind of that have ever been cast, and were made in Stockton, CA.

Stay tuned for our next post, about more interesting features of the new east span.

Click here to learn more about the San Francisco – Oakland Bay Bridge.

Innovative Stormwater Management at Hillside Residence in Kentfield, CA

June 28th, 2012 by

Image credit: David Wakely Photography

Nestled into a hillside in Kentfield, California, Sherwood worked with Turnbull Griffin and Haesloop Architects, Redhorse Constructors and GLS Landscape Architecture, to design an award-winning residence focused on sustainable site design and water reuse. Due to its location and unique topography, a complicated retaining wall and drainage system were required, with integrated drainage solutions designed into the paths that traverse the steep hillside. With these paths serving as level spreaders, and the integration of a living roof, rainwater is captured in a stormwater basin for on-site reuse. By including a pool that follows the natural shape of the hillside, and other hardscape features that facilitate site drainage, Sherwood was able to design a residence that exemplifies sustainability while fitting seamlessly into the surrounding landscape.

The project was featured in the 2011 AIA Marin Living Homes Tour, and recently written up in Arch Daily! Read the article here.

Image credit: David Wakely Photography

Image credit: David Wakely Photography