For More Information please follow this link to the city of Rochester website at www.rochesternh.net and click on the North Main Street Bridge icon in the scrolling banner.

Construction Advisory: Week July 27-30, 2010

Contact:  Kathryn Buxton, 207-775-2802,  k_buxton@buxtoncomm.com

Crews complete retaining wall, continue prep for span one repairs

Rochester, NH – Contractors have completed work to rebuild the mortar-and-rubble
retaining wall on the southeast side of the North Main Street Bridge. The wall
has been topped with a granite capstone to match the granite on the historic
bridge. This work was completed several weeks early, as the utility companies
continue to finalize plans to move electrical and gas lines. Additionally
representatives from the engineers, the city and contractor are continuing to
develop plans for additional repairs to the 127-year-old bridge.
Below is a look at work expected to take place at the construction site this week.
• Wyman & Simpson, the bridge contractor, will continue to assemble and install
shoring for the span one arch. The shoring will protect the structure while crews
repair the arch and piers in that section of the bridge. The shoring will rest on a
bed of gravel that has been brought in by the contractor to help create a stable
work surface for the arch repairs.
• The contractor plans to drill more test holes at the gutter line on the upstream
side of the bridge. The engineers have requested the additional work in order to
get a better look at the condition of the mortar in that section of the bridge,
where water and road salt appear to have caused more deterioration than
originally thought.
• Masons will continue to grind out the old mortar for repointing the brick-andgranite
arches.
For more information about the bridge rehabilitation project, visit the Rochester
Public Works Department bridge web site or Facebook page.

Construction Advisory: Week July 19-23, 2010
Masonry work to begin on retaining wall

Rochester, NH – Below is a look at developments in the bridge rehabilitation plan
and activities planned for the construction site this week:

• Tests have been performed on the mortar at various locations. That closer look
has revealed more damage than anticipated, particularly at the gutter line where
road salt has eaten through several courses of the brick mortar. Moisture also
has caused more deterioration on the underside of the brick arches. Masons will
need to replace 90 percent or more of the mortar, about 25-30 percent more
than specified in the original bridge rehabilitation plan.

• Dewatering of the span has taken longer than anticipated, because the bridge
was built on dry laid stone. That has meant that water has been seeping through
the stone and inside the cofferdam area. The contractor has jury rigged a
system to partially seal out the water and will continue pumping water out of the
area throughout the construction. It also means crews will not have as dry an
environment as is optimal to complete the repairs to the piers and the underside
of the brick arch.

• Crews will begin to install metal shoring underneath span one. The shoring will
support a plywood form to secure the brick arch during repairs to the span
structure.

• Crews performed demolition of the old mortar-and-rubble retaining wall on the
southeast side of the bridge last week and successfully installed a concrete
footing for a new wall. This week, they will begin to rebuild the wall. Originally
scheduled to be performed near the end in the project, this work has been
moved up as details are being worked out regarding the condition of the bridge
and additional repairs required.

• Last week, representatives from Wyman & Simpson, the City of Rochester and
bridge engineers met to discuss a plan for completing the additional repairs.
While an amended plan is still in the works, it is now clear that construction will
take longer than the 105 days outlined in the original rehabilitation plan. The
city is exploring alternatives to the project traffic plan to accommodate an
extended construction schedule.

For more information about the bridge rehabilitation project, visit the Rochester
Public Works Department bridge web site or Facebook page.

Construction Advisory: Week of June 28 - July 2, 2010

Dewatering, asphalt and sidewalk removal planned

The sheet pile cofferdam at the base of span one of the North Main Street Bridge has been completed. This week, crews will be working both on the bridge deck and underneath the historic 127 year old bridge.

Here's a look at the activities planned for at the work site this week:

* Wyman & Simpson, the bridge contractor, will begin "dewatering" the area inside the cofferdam constructed around the base of span one. The water will be pumped into a basin where sediment and sludge will be filtered out before the water is gravity fed back into the Cocheco River. The contractor also expects to place sandbags at key areas to help seal the cofferdam and prevent water from entering back into the work area.

* Subcontractor S.U.R. Construction will deliver a dump truck and excavator to the site on Tuesday to help with demolition of the asphalt pavement, the granite curb and upstream concrete sidewalk later in the week.

* A mason will run test panels to determine a good color match with the old mortar used in the original construction of the bridge.

* A rack truck will deliver metal supports to the work yard. The supports, used in conjunction with a plywood form, will shore up span one while masons repair the brick arch.

The City, the contractor and utility companies will have continued discussions about moving some of the utility currently located in the old, downstream concrete sidewalk and are at work on the long term solution. The recent discovery that there are 16 utility ducts housing electrical, phone and natural gas lines embedded in the concrete sidewalk will require additional engineering and work by utility companies. What impack that work will have on the construction schedule has yet to be determined.



Construction Advisory: Week of June 21 - 25, 2010

Construction to continue on cofferdam 

During the week of June 21 - 25, construction activity on the North Main Street Bridge will continue to focus mainly on span one on the west side of the historic, 127 year old bridge.

Construction planned for the week:

* Completion of the sheet pile cofferdam around the base of span one. The cofferdam is a temporary structure that will be used to keep water out and provide a stable, dry environment for repair of the brick and granite arch.

* Completion of the plywood staging for workers repairing the outside surface of the bridge, including a debris catcher to prevent construction and demolition materials from falling into the river.

* Begin construction of a sediment basin to filter out soil and sludge from water pumped from around the base of span one. The basin will collect the sediment before the filtered water is returned to the river.

* If time and weather allow, crews also may begin demolition of the concrete sidewalk on the upstream side of the bridge.

Inspection results:

A closer inspection of the bridge during the past two weeks indicates some more work may be needed than originally anticipated. That includes additional repointing (replacement of aging mortar) in the brick arches because time, water and road salt have caused more damage to the mortar than first was thought.

The inspection also revealed that telephone, electrical and gas lines are all located within the sidewalk on the downstream side of the bridge. This could complicate removal of the old sidewalk. Additionally, modern safety standards recommend the separation of utility lines. Pending discussions between the city and Public Service of New Hampshire (PSNH) and Unitil, plans are to move one of those lines.

Work began on the bridge on June 1st and originally was expected to be complete in mid-September. The additional repair work required on the brick arches is not expected to impact the construction schedule, although timing of the utility line changes could.

Construction Advisory: Week June 7 - 11, 2010

Downtown banner to decorate North Main Street Bridge site

Construction activity will begin to gear up at the site of the
North Main Street Bridge rehabilitation during the week of June 7 through
June 12.
 
Late on Tuesday afternoon, June 8, volunteers plan to put up a large banner
on a wall that is being built on top of the concrete barriers that cordon off the
construction site. The colorful banner is meant to provide an attractive
barrier around the construction site. It urges residents to "Shop Downtown
Rochester" and features silhouettes of local landmarks and buildings.
 
In all, there will be 200' of banner hung from the barrier wall. Viking Design
of Rochester created and donated the banner design. The banner was printed
by Custom Banner, also of Rochester, with funding from the Bridge Mitigation
Plan. It is actually a series of seven smaller banners varying in length from
10' to 40'. The labor to put the banner in place is also being donated.
 
"The repair of the bridge is important to residents and businesses of
downtown Rochester, because it is an important piece of the city's history
and provides a vital entrance to the downtown business district," said Karen
Pollard, economic development manager for the City of Rochester. Pollard
said the banner is one of several ways they are reminding people that local
businesses are open, and there is plenty of parking available.
"It's important to let people know that it is still easy to get to your favorite
North Main Street businesses on both sides of the bridge," said Pollard.
 
During the first full week of construction, the bridge contractor Wyman &
Simpson also anticipates moving equipment and materials into place, as
crews prepare for repairs to the understructure of the bridge's third arch.
 
For more information about the bridge rehabilitation project, visit the Rochester Public Works Department bridge web site or www.buxtoncomm.com

Construction Advisory: Week of May 31 – June 5, 2010
Work to begin June 1 on North Main Street Bridge project
Rochester, NH – The North Main Street Bridge will close to all vehicle and pedestrian traffic
on Tuesday, June 1, as bridge construction crews begin work to preserve the 127-year-old
structure.

Wyman & Simpson of Richmond, Maine, and its subcontractor S.U.R. Construction of
Rochester have been at work in recent weeks setting up signage and marking pavement in
preparation for the closure. A detour will lead traffic around the construction site. Only the
bridge will be closed. Patrons will be able to access businesses on North Main Street near both
ends of the bridge throughout the anticipated 105-day bridge closure schedule.

“We may have to limit traffic for safety reasons when there will be heavy equipment or
materials moving into and out of the construction site,” said Brian MacFawn, project manager
for Wyman & Simpson, “but we anticipate those delays being brief.”

The detour will take traffic over the Cocheco River via Bridge Street near the intersection of
Union and North Main streets. From there, motorists can connect to Farmington via Route 11
and Concord via Route 202.

Also, signs recently went up regarding new parking restrictions on River Street between
Bridge and Chestnut Streets. No parking will be permitted anywhere on River Street between
Bridge and Chestnut Streets between 6 a.m. and 6 p.m. The city has said the parking
restrictions will be strictly enforced during the bridge closure.

MacFawn said that during the few first days, most of the activity will involve setting the stage
for the bridge rehabilitation work to come. Temporary barricades at both ends of the bridge
will go into place on June 1. Concrete barriers will be set into place on Wednesday, June 2. By
June 7, crews will help erect a banner that is being prepared for the project by local
businesses.

Rochester’s three-arched North Main Street Bridge was designed and built between 1881 and
1883 by Silas Hussey, Jr., the city’s master stonecutter. Its 50-foot width was uncommon at
the time. The heavy brick arches are faced with split granite and make this bridge unique in
New Hampshire. The historic structure crosses the Cocheco River, one of 16 protected rivers
in the state, and serves as a gateway to the city’s downtown district. The original cost for the
bridge construction $13,800 in the late 1800s. The budget for engineering, rehabilitation of
the bridge and additional road reconstruction is $1,700,000.

For more information about the bridge closure, including a map of the detour route, visit the
Rochester Public Works Department bridge web site or Facebook page.

Update posted  5/13/10:   Preliminary work for the rehabilitation of the North Main Street Bridge will begin Monday, May 17, 2010, with the erection of signage, the installation of a temporary traffic signal at the intersection of North Main Street and River Street and the temporary widening of the intersection of Bridge Street and River Street.  This preliminary work is in preparation for the closure of the North Main Street Bridge, which is slated to close on or about June 1, 2010.  

When the bridge is closed, local traffic traveling on North Main Street will be detoured around the bridge using River Street and Bridge Street.  River Street is a narrow, largely residential street not suited for larger trucks.  As a result, truck traffic will be routed around the perimeter of the City using the Spaulding Turnpike.  Local truck traffic that needs to access northern side of the City should use exit 16 of the Spaulding Turnpike to Route 125 and truck traffic that needs to access the south side of the City should use the Spaulding Turnpike to exit 11 or 12 to Route 125 rather than using North Main Street (Route 202A) and South Main Street (Route 108) through the downtown area.

Once closed, it is expected that the bridge will remain closed and all detours will be in effect until mid September, unless the condition of the brick arch work under the pavement is worse than expected.

Even though the bridge will be closed to all traffic, all of the restaurants and businesses that are near the bridge as well as the adjacent downtown area will still be very accessible during the construction.  Accommodations will be made to access and parking will be available for patrons of those businesses near the bridge.