Note: “OTHER” includes Oakland plaza, demolition, road construction, escalation to 2002, roadway construction, supports, ground motion, life cycle cost, and post--earthquake repair cost.

A VISIONARY DESIGN FOR THE 21ST CENTURY

The bridge is a sequence of linked soaring curved diamondlike structures, strung like a chain of jewels  on a necklace.

The CES bridge, unlike current proposals, centers around the beauty experienced by the driver crossing the bridge.

The design draws both its beauty and its cost saving, from the efficient action of the pierced plate girders. The light colored concrete plates, glistening in the light of the bay, pierced with beautiful openings, and working together with X--braces, tension cables, and stiffening ribs, create a new bridge technology.

In the tradition of Maillart, Nervi, and Calatrava, concrete and steel are used together, in an efficient combination.

Concrete is used in an efficient deep thin plate girder structure to create strength, stiffness, and shapes of great beauty, which are efficient in cost because of their light weight, and reduction of material.

Steel is used in its most efficient tension cable mode to create a light airy structure, of low cost.

In this bridge, ornament and efficient structure are combined, to produce something technically exciting, highly efficient, yet ultimately appealing to the most romantic elements in people of the Bay Area who will see this bridge every day of their lives. The bridge is part of the identity people feel, and it must be able to play that role, and to etch itself into peoples mental and emotional life.

STRUCTURE

An Innovative State--of--the--Art Structure Which Makes Maximum Use Of Modern Concrete Technology

• Precast concrete, with post--tensioned cables
• Cantilever perforated plate girder, carrying in--plane loads
• Plate girder uses stiffening ribs and 3--D geometry to increase resistance to buckling and out--of--plane loads
• Between the two parallel plate girders, tension cables and compression struts carrying out--of--plane loads
• Two--deck bridge makes use of high space between upper and lower as a giant low cost truss. Upper and lower decks span in transverse direction to minimize span and deck cost.
• Foundations use many small piers, to spread load over mud foundations, minimizing total foundation cost, in fashion similar to Caltrans foundation proposals
• Shell of vertical wall is heavily pierced to reduce weight and cost. In some portions, shell makes use of orthogonal tension and compression lines in a diagonal arrangement.
• The design works because we take a certain volume of concrete, and distribute it more efficiently, with more differentiation. We use less cubic meters of material, and pay more for the added differentiation, but come out ahead economically.
• At every opportunity we increase the differentiation by moving material as far apart from other material as possible, thus increasing moment of inertia in every direction.

DYNAMIC BEHAVIOR

An Innovative Structure specifically designed to damp oscillations during dynamic loading in a major earthquake

CONSTRUCTION TECHNIQUE

Erection Sequence

In general, plate elements will be pre--cast, floated on barges, then lifted into place.

As elements are lifted into place, they are tied together, and given tension behavior, by post--tensioning steel cables which lie in ducts within the concrete shell members.

Each double cantilever (diamond) has a balanced design, which allows incremental addition of pieces, two at a time.

On occasion, some plate elements might be made by tilt--up techniques, using the road bed itself as a casting slab.

Footnote: The braced and stiffened plate girder design might also be realized in steel, instead of concrete. Using advanced braced plate design, and hollow box sections. We are currently exploring this option.

TRANSPORTATION

the bridge provides a full--spectrum mix of cars, trucks, buses, carpool lanes, trains, bikes, pedestrians and ferries

• High speed passenger trains are slung under bridge deck in underslung high--speed tube to reduce weight and cost.Train tracks and space and structure for trains is provided within bridge price.
• We believe the underslung train design can be extended to be underslung on the existing West span of bridge, allowing continuity to San Francisco without heavy increased costs on West span, and without taking away a lane of traffic on the West span. To add trains to the existing Caltrans design a lane of traffic would be removed, a drastic step that is unwise and not politically feasible given inevitable traffic volume increases in the future.
• Bicycle lanes and pedestrian lanes are provided in their own arcaded structures, with arches and openings, and views, easily constructible in the braced plate design without increase of cost.
• Bikes and pedestrians are placed in their own enclosed space, with beautiful view, making the journey worthwhile and safe, and sheltered from the freeway vehicles.
• Quiet high--speed trains passing over the bridge is a feature which will identify the 21st century character of the bridge and will be experienced daily.

THE DRIVER

This Bridge, Unlike Current Proposals, Centers Around The Experience Of Driving

The space of the lower deck is high (18 meters, or about 5 stories) and filled with light.

Because the bridge is narrow, drivers see the views from both sides, and the views are framed in the open arches of the side wall.

Beautiful daylight coming in from the sides.

Breezy to make driving a beautiful experience

Arches along the sides

High and graceful

Big arches to drive through

Lights in all openings

Beautiful lighting at night, illuminating the bridge, and given by the shape of the bridge structure without extra cost

Driving along the upper deck, the driver is passing through the spaces created by the superstructure of the plate girders.

View to water, sky, Oakland and San Francisco, framed by the openings in the girder.

Our models of the lower deck show a beautiful arched structure, twice as high as the present lower deck, with light, breeze, and beautiful views.

PEDESTRIANS BIKES

BOATS

An Asset to the Bay Area

• We envisage the new bridge as providing not only transportation, but also a destination for all kinds of users.
• The top of the main tower of the bridge is to be a major destination, like the Statue of Liberty, for enjoyment by pedestrians, bikes, and people arriving by boat and train. The main bridge tower has, at its topmost point, an observation deck, which can be reached by boat, by walking in the pedestrian arcades, or by bike, and by the suspended train.
• Pedestrians and cyclists are protected physically and acoustically from heavy traffic. They have beautiful arched openings looking to the north and south Bay.
• The shaped character of the arched spaces created under the bridge and its diamonds, provide a beautiful destination for sailboats and an experience from the water which is valuable.
• Main span near Yerba Buena Island will add to amenities of Treasure Island development.
• Bicyclists can easily and safely travel to and from Oakland and San Francisco. Bike path can be integrated with the growing Bay Shore trail.

THREE GREAT BAY BRIDGES

The new design has a very strong relationship to the two great Bay Area bridges, the Golden Gate Bridge and the West span Bay Bridge. As can be seen in the photograph of all three bridges together, the three form a family together.

The new bridge respects the two older great bridges, and the cluster of three bridges adds significantly to the value and importance of the Bay.

CROSSOVER ALIGNMENT

We have not had time or sufficient information to fully assess the alignment problem. However we make the following preliminary observations:

• We have identified a southern alignment bridge solution which runs from the northern edge of the Oakland mole (leaving the new Oakland Gateway park intact as planned on the south side of the mole), yet arrives at Yerba Buena on the southern alignment, fully meeting San Francisco's stated requirements.
• It is mainly a problem of construction sequencing, and we have provided a first engineering sketch for the alignment and for the solution to the construction sequence. The innovation is made possible by the geometry of our bridge design.
• We believe this crossover alignment may be able to reconcile the interests of the two cities, and recommend that meetings to this end be held as soon as possible.
• We have not yet received detailed soils information for the south side. According to our (incomplete) information, soils testing on the south side is positive, but incomplete.
• It should be noted that soils testing for a southern alignment, if actively pursued, might add both cost and delay.

CURRENT STATUS