Steel deep foundation piles with concrete poured inside.
Elevator foundation erected on right hand side. New stairway and elevator floor penetration at the top.
Another view of new elevator foundation
Geothermal heating system being installed
Holes are drilled to 300 feet
Clay and silts suck out from boring holes. Artifacts of bones, shoes, and other household materials were found.
Boring view form tower
300 foot long geothermal pipe. Rounded end goes into the ground
Unconnected end stick out of 300 feet deep hole waiting to be connected to the entire system
36 holes will be drilled
System will be pressured test to make sure there is no leak in all 36 pipe.
Water retenion vault mandated by the city of seattle for construction site. When water fill up to 2 feet near asphalt it gets drained into sewage.
Depp pile foundation support grade beam which in turn support new column. New column will pair with original column for greater seismic resistant. New column will (+ sign shape in picture) pierce up to attic level.
Graded beam form installed
Grade beam steel reinforcements passes through pile to transfer loads from new column
Grade beam casted
Three layer of granite shown are currently connected only by weak motar. New holes is drilled and reinforcements are added for shear resistant.
Extracted original granite in preparation for steel reinforcement insertion.
Originalsteel from under Jackson plaza. This is why Jackson plaza needed to be demolished.
King Street construction 9.15.10 website update
Phase 2<br />In this slide show:<br />Jackson Plaza demolition<br />Thermal heat pump well drilling<br />Water retention vault install<br />September 23, 2010 Update<br />
Looking southeast at the first floor just north of the main waiting room. The space will eventually hold Amtrak operations. Round stubs in foreground are structural piles that will support steel needed to meet seismic upgrade standards.<br />
First floor just north of the main waiting room. The hole in the ceiling and the foundation below provide space for an elevator and emergency stairways linking the first three floors.<br />
A close-up view of the elevator foundation from the previous slide.<br />
A special rig drills geothermal wells that reach 300 feet below the surface. 36 wells will be drilled in the area below the Jackson Plaza.<br />
A close-up view of the drilling rig with well pipes in the foreground.<br />
A worker closely monitors the drilling. Clay and silt pour out. Artifacts of bones, shoes and other household materials were found.<br />
An aerial view of the drilling rig facing north.<br />
Long coils of geothermal piping which are inserted into the finished wells.<br />
These stubs of geothermal piping reach 300 feet into the ground. They will eventually be connected to a super efficient heat pump for Station heating and cooling systems. The well and heat pump systems save energy and avoid the need to install more costly heating and cooling systems.<br />
About two wells are drilled each day—a total of 600 feet down. <br />
The well system will be tested to make sure there are no leaks in the piping for all 36 wells. <br />
A large pit is excavated just northwest the Station’s main entrance. It will hold a storm water detention tank. <br />
The tank can hold water from major storms that would overwhelm the sewer system. Above shows the tank, below it’s being covered. <br />
Re-bar surrounds the black, round pile (at center), which extends deep into the ground attaching to the bedrock. This network of re-bar and deep piles will form a grade beam foundation slab. This beam supports new, steel columns that will pair with the Station’s original frame providing stability during seismic events. The two large steel crosses poking out of the re-bar are the beginning of these columns.<br />
A wooden form is constructed so that the grade beam concrete can be poured, forming a continuous beam attached to deep piles that will stabilize the Station in the event of an earthquake.<br />
The grade beam steel re-bar passes through holes in the deep pile, which allows the pile to bear the loads of the new structural column. When completed the grade beam will be a solid concrete structure with the steel inside.<br />
Completed, concrete-cast grade beam. This is the re-bar and pile structure shown in previous slides after concrete as been poured.<br />
This exterior wall lining the Station Plaza is made of giant granite pieces. It was never attached with more than simple mortar. Holes are bored to insert structural steel tying the Station walls together.<br />
A close up of the granite core from the wall. Steel will be inserted attaching the granite pieces to the Station. When originally installed the wall essentially rested in place using weight and gravity.<br />
These corroded chunks of steel where part of the original Jackson Plaza structure recently demolished. After over 100 years of service these beams have eroded—that’s why re-building the Jackson Plaza is so critical.<br />