The 600 block of Walnut Street has been closed at various times this week for remedial work.
Contractors are currently scrambling to finish remedial work on several Walnut Street sidewalks. The sidewalks are part of an overall road project on the 500 and 600 blocks that includes road paving, curbs, and ramps. As
Columbia Spy reported
HERE, property owners on the two blocks complained to borough council recently about various problems with the project.
C.S. Davidson's Derek Rinaldo (second from left) reports on the Walnut Street road project.
In response, engineering firm C.S. Davidson provided information and updates on the project at the borough’s November Public Works and Property Committee meeting. The firm’s representative, Derek Rinaldo, who serves as the borough’s Engineer of Record, told the committee, “We’re aware of several issues on that street right now.” He named cracking concrete, blocked drains, and overspray as a few of those issues. Rinaldo said he developed a punch list of over 20 items after walking the site several times with the borough’s Ron Miller and Jake Graham. [Miller is Public Works Director, and Graham is Highway Department Manager.]
Regarding concrete cracking, Rinaldo said, "We're not concerned with the integrity of the concrete." He pointed out that the concrete used for the job is rated at 4,000 psi and must meet borough standards based on PennDOT 408 specifications that govern various aspects of construction.
Two sinkholes opened up on the 600 block.
During sidewalk installation, another problem became apparent: a sinkhole that opened near 647 Walnut. Rinaldo said a urethane injection method is typically used to fill in any voids and spaces associated with a sinkhole. In the process, a spray foam is injected underneath the road and curb, which expands to fill the affected area. A second sinkhole opened this past Sunday, near 651 Walnut.
Contractors are also filling in the so-called "beauty strips" with concrete.
Rinaldo noted that water was flowing over the curb and onto the sidewalk during high-intensity rains. He explained that the problem stems from the fact that the 600 block of Walnut takes drainage from the three blocks further up as well as from several side streets. To help resolve the problem, drains will be added in the 700 and 800 blocks during next year’s planned road project. Contractors are also filling in the so-called "beauty strips" with concrete to control water.
Contractors are working to correct problems on the 600 block of Walnut Street
Another possible factor contributing to drainage problems, according to Rinaldo, is the street’s high crown. Unfortunately, lowering the crown would require tearing up and totally reconstructing the street, potentially adding several hundred thousand dollars to the cost. Rinaldo said testing and core samples of the street did not show a need for reconstruction, because the base is strong. Profile milling was done instead; that is, taking a very small amount of material off the top and replacing it with petromat, a fiber-containing paving material that provides an extra layer of strength over trench cuts and divots.
Problems on the 500 block are also being addressed.
Rinaldo explained that other jobs he's been involved with in the borough did not have these kinds of problems and that this is the third or fourth project he's done with Pennsy Supply. Pennsy installed the sidewalks on the 600 block, while a subcontractor, Sauder Brothers Concrete, did the 500 block. The total project cost for the two blocks was a little over $432,000. Rinaldo said no contractors have been paid so far.
[UPDATE 11/30/18: According to a source, contractors have been paid, except for the final 5%.]
