It's the sort of thing that a structural engineer ends up pondering through the dinner hour two elevators, two staircases, a mezzanine, escalator, customer counter space all in a 35-foot by 95-foot space.
"It's a busy footprint," says Terence Toby, of Toby Wade Structural Engineers, and the Amtrak train station posed a few engineering challenges along the way.
But essentially despite the once-in-a-lifetime nature of the project it's been a typical job for a structural engineer.
Like most, it offered a the challenges, some slam-dunks, and lots of meetings along the way.
Toby Wade structural Engineers came in on the design-build project right in the beginning, says Toby.
The station, designed by VBN Architects of Oakland, Calif., is being built by Northern Sierra Construction, Inc.
Most of the engineering work was done in 2003, says Toby, and the bulk finalized last year.
The project itself is on a timeline headed for completion late this year, and Toby is on call for review and explanation whenever needed.
The station sits on the ReTrac trench's slab, and the slab is massive, says Toby, about three feet thick.
The building also snuggles up against the trench's walls, which are also massive at one to two feet thick.
And that was part of the challenge of the project, he says, building on top of another engineer's slab.
That requires early, and continuing, coordination along with several meetings.
"In general, though," he adds,"the trench walls are so massive and strong that they can easily support one building."
The train station sits 24 feet down in the trench, Passengers check in at street level, descend via elevator, stairs or escalator past a mezzanine and to the passenger loading level in the trench.
All along the way, glass and open space plays into the engineering puzzle.
First the glass: Both elevators sport glass or partial glass enclosures.And a solarium protects an outside escalator that descends to the loading zone.
The building is fronted with a 12-foot paned-glass window, and 10-foot arched windows top the doors.
As much open space as can be packed into a 4,000-square-foot footprint is packed in.
Passengers at the mezzanine level overlook the trench-floor level.
A 9-foot-wide walkway along the trench side of the station provides an overlook down to the train level.
"Yes, it's busy," says Toby.
But, each element is simply that from an engineering point of view an element to be engineered.
Tackled one by one.
The seismic elements provided a creative opportunity, he adds.
His firm worked on the seismic retrofits of historic school buildings in Virginia City, and comes to the table with credentials.
The seismic aspect of the design ended up being standard construction, albeit with modifications, says Toby.
The building is attached to the trench wall with slotted connections.
If the wall moves, the connecting bolts slip for give in the rigidity of the connection.
It's always a bit of a challenge, too, when segments of a building are built on anything other than right anbles.
One of the elevators is on a tighter angle just another architectural design element to ponder over dinner, says Toby.
And since the building, designed to echo the historic train station to the east of it, is attached to that building, doors out of the east wall join up with doors in the west wall of the existing structure.
