Prepared by the Capitol Visitor Center Project Office, Architect of the Capitol, December 16, 2002

This Week - Ongoing Work - 12/16/02 through 12/20/02

• The majority of CVC related construction activity is now occurring within the construction fence and the site is secured by the U.S. Capitol Police.
• Significant tunnel construction activity continues in New Jersey Avenue NW, along upper Northwest Drive and in Constitution Avenue NW just east of New Jersey Avenue NW. Additional tunnel work may begin late in the week on the East Front Plaza adjacent to and within a portion of the Senate triangular parking area (details are provided below under “Senate side” activities).

East Front Plaza Work (Inside the Construction Fence)

• Construction of the CVC foundation walls continues on the north side of the site. Concrete placement continues and two large construction vehicles fitted with “clamshell” buckets will continue to excavate the foundation wall trenches. Both clamshell excavation vehicles are situated on the north side of the site and one of the vehicles will continue to work immediately adjacent to the east face of the Capitol this week.
• A plastic tarp will continue to be suspended from the roof of the Capitol at various locations along the north side of the East Front to protect the building facade from construction vehicle emissions. During the next few weeks, the tarp will be suspended for approximately two days at any one location and it will be repositioned as CVC excavation work progresses along the East Front facade. The tarp is approximately 20 feet wide and it will obstruct windows temporarily on the First and Second Floors where it is situated. The tarp will not obstruct windows on the Third and Fourth floors although the ropes that support the tarp from the roof will be visible.
• Earth-moving and soil removal activities continue at several locations across the East Plaza.
• Excavation for the guide walls continues on the House side.

House Side (Outside the Construction Fence)

• Work has been completed at the south planter with the installation of permanent granite piers and additional landscaping enhancements.
• The South Door, the House Steps and the House Carriageway Door remain accessible to pedestrians throughout construction.

Senate Side (Outside the Construction Fence)

Tunnel Construction

• CVC tunnel construction work is expected to begin later this week on the East Front Plaza adjacent to and within the Senate triangular parking area. Crews will begin placing Jersey barriers along the west side of the plaza on both sides of the tunnel construction zone. The drive lanes and vehicle barricades will be shifted slightly to the east of the Jersey barriers, but the drop-off location under the canopy will not be affected. Pedestrian access will be maintained on both sides of the construction zone. Alternate parking arrangements have been coordinated with the Senate Parking Office to offset the partial loss of parking spaces on the Plaza due to this activity. The tunnel construction work on the Plaza will continue for approximately 12 months.
• CVC tunnel construction work continues in a portion of upper Northwest Drive and this work will last approximately 12 months.
• CVC tunnel construction work continues along the east side of New Jersey Avenue NW between Constitution Avenue and C Street. The east sidewalk in this location will continue to be closed, but the west sidewalk is accessible. The street will continue to be restricted to one lane and one way traffic traveling southbound.
• Excavation work related to the CVC service tunnel continues in the center portion of Constitution Avenue NW just east of the intersection of New Jersey Avenue NW. Two lanes of traffic are being maintained in each direction. Alternate parking arrangements have been coordinated by the Senate Parking Office. Pedestrian access is maintained on both the north and south sides of Constitution Avenue. The tunnel work in this zone will continue for several months.
• Exploratory test pit drilling will continue on the plaza along the alignment of the CVC service tunnel.

Utility Work

• CVC utility work will continue in the street at the intersection of Louisiana Avenue NW and New Jersey Avenue NW. Traffic patterns have been reconfigured to accommodate the construction crews, but traffic flow and entry into the Senate garage have not been impeded.
• Utility work begins near the intersection of D Street NE and First Street NE. Some parking spaces will be affected, but alternate parking arrangements have been coordinated with the Senate Parking Office.

Pedestrian Access

• The North Door, the Senate Steps and the Senate Carriageway Door remain accessible to pedestrians throughout construction.

Next Week - Anticipated Work - 12/23/02 through 12/27/02

East Front Plaza Work (Inside the Construction Fence)

• Foundation and guide wall excavation and construction will continue in locations across the CVC project site. Some large equipment will continue to be situated close to the east face of the Capitol building on the north side. The East Front facade is being protected by a protective tarp that is being suspended from the Capitol roof along the portion of the building where excavation work is occurring.

House Side (Outside the Construction Fence)

• No work scheduled.

Senate Side (Outside the Construction Fence)

• CVC tunnel work will continue in a portion of the East Front Plaza, Northwest Drive, along New Jersey Avenue NW, and in Constitution Avenue NW, just east of New Jersey Avenue NW.
• CVC utility work will continue in the street at the intersection of Louisiana Ave. NW and New Jersey Ave., NW.
• Crews will continue digging test pits at the intersection of D Street NE and First Street NE to determine existing conditions for CVC utility-related work required in this zone.

Description of Foundation Wall Construction Process

Construction of the outer foundation walls for the CVC occurs in a series of steps. First, approximately 8 feet of the existing ground is removed along the perimeter (footprint) of the CVC to clear the way for construction of concrete guide walls. Guide walls are two parallel walls that measure 18 inches wide with a height that varies between 4 and 8 feet, depending on the existing elevation. The walls are aligned so that an approximate 3-foot gap is maintained between them. Once the guide walls are in place within a specific zone, a large red “clamshell bucket” is lowered into the gap between the walls and the bucket is used to excavate a narrow trench to an approximate depth of 70 feet. A muddy mixture called “slurry” is poured into the trench as soil is removed. The slurry maintains the stability of the side walls of the trench until a steel rebar cage is emplaced within the trench and concrete is poured. As the concrete fills the trench, the slurry is displaced, removed and reused. Once the concrete within the trench cures, a portion of the outer wall of the CVC is established. As the outer wall of the CVC is completed, excavation will continue inside the wall to a depth of approximately 50 feet. The slurry wall construction process, especially where it occurs adjacent to the Capitol Building, minimizes any potential disruption to the Capitol Building foundation, since the CVC foundation walls are formed and in place before deep excavation begins.

If you have any questions about the Capitol Visitor Center Project, please contact Tom Fontana, CVC Project Communications Officer for the Architect of the Capitol, at (202) 228-1310, or by e-mail at tfontana@aoc.gov

If you experience any problems with building services inside the Capitol, please contact the Capitol Building Service Center.