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When it was decided that the Albert Schultz Jewish Community Center of Palo Alto, Calif., would be evicted from its headquarters building of 30 years, the search began for a new home. At the same time, the Jewish Home of San Francisco was looking to extend its reach into Silicon Valley to provide more independent and assisted living senior housing. The partnership embarked on the most ambitious development plan in Palo Alto in more than 20 years — to take an underutilized and polluted urban site and turn it into a small city.
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The Taube Koret Campus for Jewish Life (TKCJL) is a new mixed-use development located in Palo Alto, Calif., located on an 8.5 acre "brownfield" site that was formerly the location of the Sun Microsystems headquarters. The TKCJL aims to be, as described on their website, "a welcoming, innovative, multigenerational destination where individuals and families can live, learn, play, and connect. Anchored by a world-class community center, the Oshman Family Jewish Community Center, and a progressive new senior living community, the Moldaw Family Residences at 899 Charleston, the Campus is transforming the region's Jewish community and energizing the Palo Alto area and all its residents."
Virtually the entire campus is covered by a one-story podium structure containing 620 parking spaces. The podium level, approximately 14 feet above grade, supports eight four-story concrete towers dedicated to independent, assisted, and memoryassisted senior housing, a fitness center, and a theatre as the cultural focal point. The campus format allows its residents all of the benefits of city life without the challenges seniors face in an urban environment such as level changes and traffic. The theater and cultural hall features retractable seating and a rooftop outdoor terrace with sweeping views of Silicon Valley. The Jewish Community Center also features a nursery school with 13 classrooms and a large outdoor fenced play area, an after school learning center, a café, a cafeteria for residents, retail space, and office space for several non-profit organizations.
The campus is laid out on two overlaying intersecting grids, skewed at 7 degree angles. The result, as devised by the campus architects, is a feeling not unlike walking through an ancient or medieval city in Europe or the Middle East as you journey between the 12 individual buildings and the nine "link structures" that weave the campus together. While the structural design of the campus employs fairly common techniques of gravity framing and lateral force resisting systems, the challenge for the design team at Forell/Elsesser was accommodating the condensed and detailed architectural design of this intricate "small city" and the multiple uses of the various buildings while creating economical structures with as many sustainable design attributes as possible. An additional challenge was maintaining consistency in the structural systems and structural detailing throughout the 12-building campus, with hundreds of design team members, contractors, and end-users contributing their input.
The Taube Koret Campus for Jewish Life (TKCJL) is a new mixed-use development located in Palo Alto, Calif., located on an 8.5 acre "brownfield" site that was formerly the location of the Sun Microsystems headquarters.
The entire campus is built on top of a concrete podium designed for a minimum of 200 pounds per square foot to account for live load, planters, lawns, and art.
The TKCJL aims to be "a welcoming, innovative, multigenerational destination where individuals and families can live, learn, play, and connect."
The campus format allows its residents all of the benefits of city life without the challenges seniors face in an urban environment such as level changes and traffic.
In the foundation concrete as well as the concrete columns, beams, and walls, a 50 percent replacement mix of slag and fly ash was used instead of cement. In the post-tensioned flat plates, a 35 percent replacement binder mix was used.
The 8.5 acre Taube Koret Campus for Jewish Life in Palo Alto, Calif., represents a new national model for intergenerational activity.
This 12-building project was very challenging for the structural engineering team. The complexity of the integrated campus required more coordination than a typical project would, both with the architect and the contractor.
The Taube Koret Campus for Jewish Life is now open and has been an immediate success and a national model for intergenerational activity. The Forell/Elsesser team is very proud of our contribution to this national landmark campus.
Structural design
The property was considered a "brownfield" site due to transient toxic pollutants traversing through the soil below ground. Because of this, the site was limited to shallow foundations supported on poor soil. Because drilled piers or piles could not be used, spread footings were used to resist gravity, lateral, and uplift forces. A heavy duty "liquid boot" and an active and passive gas extraction system were installed below all slabs-on-grade to prevent any toxic vapors from rising to the surface.
The podium level is framed with a conventionally reinforced concrete slab, ranging in thickness from 12 to 16 inches, with the top sloped to drain. The varying layout and changing load demands at the podium level required special attention from the design team. The entire podium was designed for a minimum of 200 pounds per square foot of superimposed load to account for live load, planters, lawns, stone benches, and variable architectural topping slabs. The mixture of load demands required numerous steps and slopes in both the top of concrete and slab soffits, and this required intense coordination with the architects. The "Town Square" area at the center of campus contains nine full grown palm trees in precast concrete planters weighing over 10,000 pounds each. Other areas of the podium contain corten steel post sculptures, rock sculptures, and a preschool play area with sandboxes, climbing equipment, and a shade structure. As a result, both the top of slab and slab soffit varied greatly.
The eight senior housing towers are constructed of post-tensioned concrete flat plates with concrete columns. Slabs use stud rails at column locations in lieu of drop panels wherever possible to reduce formwork costs and because the concrete slab soffits are left exposed to view in the housing units. Concrete shear walls make up the lateral system in the housing towers. Transfer beams were designed for the towers at some locations where the use of the space changes at the podium level below. Incrementally stressed post-tensioned concrete beams were used at these locations as the transfer elements.
The four large Jewish Community Center ( JCC) buildings are constructed of structural steel above the concrete podium. The main building houses most of the athletic facilities of the JCC, including an outdoor lap swimming pool, indoor children's pool, locker rooms, and gymnasium with basketball courts and retractable bleachers. The roofs over the indoor pool and gymnasium spaces span 90 feet using 32-inch deep lightweight open web steel joists. Both swimming pools are built into the podium level, and the pool walls also double as shear and bearing walls. Two other steel-framed buildings house fitness equipment, aerobics rooms, offices, and nursery school classrooms.
The theater and cultural hall includes a stage, retractable seating for 385 people, and a large kitchen facility. The theater required a long-span roof, but the space over the theater is occupiable for catered events. To support the loads, structural engineers designed 6-foot-deep structural steel trusses at 30 feet on-center that span 90 feet. The entry lobby at the theater has a 40-foot tall glass curtain wall, and the team designed the backup structure for this wall and other tall curtain walls throughout the complex. The architect designed many decorative curved shapes at or above the roof level. These were framed using curved HSS members and curved metal deck to give an organic softness to an uninterrupted structure.
The lateral force resisting system in the steel buildings is special concentric braced frames with pipe braces. Lateral forces are transferred into the podium slab diaphragm and into concrete shear walls below the podium. For the larger steel buildings, steel columns continue all the way down to transfer upward and downward loads directly to the foundation. The smaller steel buildings transfer all loads into the concrete podium structure below.
One of the most challenging aspects of this project was the coordination of structural and non-structural components within the post-tensioned concrete floor slabs. As many engineers have encountered, an early attempt by engineers to avoid conduit and pipes in the slabs was dismissed by the contractor and subcontractors as being impractical for residential construction. The items penetrating and embedded in the slab include plumbing pipes and chases, mechanical ducts, trash chutes, and light fixtures. Amidst these openings, 1.5-inch electrical conduit lay within the PT slabs at every floor with multiple crossovers. All of these items had to be coordinated with the rebar, post-tensioning tendons, and stud rails. The Forell/Elsesser design team worked closely with the contractor in the field on the senior housing tower slabs to lay out all of the items without affecting the structural integrity. Additional slab reinforcing was added around openings to ensure a cohesive diaphragm.
Sustainability
The Forell/Elsesser engineering team worked collaboratively with the design and development team to contribute to the sustainable design at the structural engineering level.
Materials and time — At the residential floor areas, our team designed post-tensioned flat concrete plates, resulting in a savings of 1,800 cubic yards of concrete and 250 tons of rebar compared to conventionally reinforced concrete slabs.
We also worked closely with the general contractor, Webcor, to maximize the percentage of replacement binder, instead of cement, in the concrete mix designs. In the foundation concrete as well as the concrete columns, beams, and walls, a 50 percent replacement mix of slag and fly ash was used instead of cement. In the post-tensioned flat plates, a 35 percent replacement binder mix was used. Stressing the post-tensioned slabs could still be performed at three days, and there were no significant delays in any formwork removal, thereby making this highly sustainable system just as time-efficient as a conventional cast-in-place concrete system. Rebar and structural steel had a very high percentage of post-industrial recycled content.
During the construction administration phase, we implemented a system of electronic review for all submittals including structural steel and rebar. On this project, which consisted of approximately 9,600 pages of submittals, the electronic process saved enormous paper volume and resources and cut the submittal review turnaround time in half.
Seismic performance and sustainability — The seismic design of the project was balanced with respect to quantity of construction materials used and anticipated limited damage to building contents. The building code criteria for seismic design are intended to protect life safety yet not necessarily to limit damage. Our team designed the institutional campus buildings so the shearwall reinforcement and concrete could be placed easily and quickly without congestion issues. The seismic drift anticipated from this design will be typical for a concrete shearwall building, and will be less than that allowed by code. A significant benefit to reduced seismic drift is that there will be less damage to both structural and non-structural elements after a large earthquake. Reduced damage increases the likelihood for repairability instead of replacement of damaged equipment, cladding, or other non-structural elements, thus reducing the use of raw materials and labor to replace those damaged items. The net benefit of this combination is that the overall life-cycle cost of the building is reduced.
Conclusion
This 12-building project was very challenging for the structural engineering team. The complexity of the integrated campus required more coordination than a typical project would, both with the architect and the contractor. The construction from ground breaking to grand opening took less than two years. The Taube Koret Campus for Jewish Life is now open and has been an immediate success and a national model for intergenerational activity. The Forell/Elsesser team is very proud of our contribution to this national landmark campus.
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Spotlight: Forell/Elsesser Engineers Allen Nudel, S.E., LEED AP (AN) a principal at Forell/Elsesser Engineers and the project manager for structural engineering for the Taube Koret Campus for Jewish Life, told Structural Engineering & Design Editor Jennifer Goupil, P.E. (JG) about some of the project details. JG: What was the most challenging aspect of the design? AN: The most challenging aspect of the structural design was the two overlapping intersecting grids. This created a very irregular column and wall layout below the podium. It took a lot of coordination to make this work. Another challenge was that irregular building configurations combined with the proximity to the San Andreas Fault required the use of linear dynamic analysis using a site-specific response spectrum for 11 of the 12 buildings. JG: What was the most unique problem to solve on the project? AN: Due to the podium's size and the tendency for concrete to expand and contract with temperature fluctuations, the podium slab was carved up into "plates" no more than 400 feet long. The joints serve as both expansion joints and seismic joints. Slab edges at the joints are supported by concrete corbels and shelves with sliding bearings that allow thermal movement in the slabs without cracking. JG: What design innovations were employed by the structural team? AN: High volume fly ash and slag concrete mixes had been used in our office for years in foundations. Using these mix designs throughout the superstructure without any schedule delay, with the help of the contractor, was very innovative, and very good for the environment. JG: Did this project have owner-required sustainable design? AN: The Taube Koret Campus for Jewish Life is currently pursuing LEED Silver certification. There were many sustainable strategies utilized on this project. Among them are developing a brownfield site, covered parking, shuttles to mass transit hubs, low water usage for irrigation, roof-top solar panels, solar water heating, and bicycle parking. JG: What engineering ideas did you implement to save project costs? AN: Electronic submittal review greatly cut down turnaround time on submittals and helped to expedite construction. Firm Facts |
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Q&A with the architect Q: What inspired you during the design process? A: The collaborative nature of all those involved in the project. The cooperative environment that my design team helped facilitate encouraged creative ideas and good thoughts to surface from the client group, end-users, industry experts, and community members. As the lead architect, I enjoyed the challenge to piecing together the diverse and sometimes conflicting input into a cohesive vision and architectural statement that reflect their own desires and interests. This has been an incredible, unique opportunity for our design team to integrate two unrelated but faith based organizations in search of a new paradigm for senior living. Q: What new design innovations were employed by the design team? A: This is the first truly mixed-use, intergenerational community in an urban setting that combines senior living with education, culture, retail, community resources, and health and wellness amenities within a continuous campus. While the urban planning principles of the project are based on the structure of a medieval city, the architecture evokes a contemporary feeling that is appropriate to the Silicon Valley. The meandering, asymmetric "walk streets" throughout the campus create a safe environment and encourage social connections, both spontaneous and planned. |
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By the numbers: The Taube Koret Campus for Jewish Life Size, shape, and type
Unique aspects
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Allen Nudel, S.E., LEED AP, is a principal with Forell/Elsesser Engineers in San Francisco. Nudel is also vice-chair of the Structural Engineers Association of Northern California Sustainable Design Committee, and is a member of SEAONC Existing Buildings Committee and AISC. He can be reached at 415-837-0700 or a.nudel@forell.com.
