Muskingum River Lock No. 4 in Washington County, Ohio was first constructed in the mid 1800’s and is still in use today. This particular lock was experiencing difficulty with its valving system and was in dire need of repair. The Ruhlin Company (TRC) was selected to perform the work with an emergency Construction Manager at Risk (CMR) contract to investigate and perform the necessary overhaul. Upon diver investigation, Ruhlin found the water passage tunnel was partially collapsed. Ruhlin began looking for a company that was well-versed in Lock and Dam work and The Ohio Department of Natural Resources (ODNR) had previously utilized Turn – Key Tunneling, Inc. (TKT) on a project rehabilitating a tunnel just upstream at Lock 10. TKT was called in to take a look and determine how best to repair the tunnel as the entry into the tunnel was limited to two five-foot openings on the ends. ODNR, TRC and TKT personnel determined that a segmental, galvanized, and coated tunnel liner plate structure would be adequate to support the loading, allow for sufficient flow and would be feasibly installed within the size constraints. TKT supplied and installed the tunnel liner plate system, completed field fabrication to connect the outlet ports with the horizontal tunnel, and made 90-degree bends to extend vertically for the valve vault reinforcement. This included the following steps to complete this work:

1. Installing of a 60” diameter tunnel liner plate with grouting of the annular space from lock chamber wall to lock chamber wall.

2. Installing outlet port steel liners that had a welded connection to the tunnel liner for all ports.

3. Connecting the two 60” vertical shafts to the horizontal tunnel and sealing it to the inlet chamber with grout. This required the tunnel liner have 45-degree miner cuts and be fitted to go together or the 90-degree bend. After planning to perform this work in the field, TKT discussed options with the tunnel liner plate manufacturer, DSI Underground, and DSI provided a price to engineer, cut and assemble the bends.

Turn – Key Tunneling, Inc. had to overcome a couple obstacles on this project. The first one was after some torrential downpours in the first three days of working, the river rose over the flood wall and flooded the entire lock, including TKT’s work area. TKT had to stop work until the water dropped below the retaining wall. Once this happened, TRC provided a few 6” pumps in the lock while TKT provided 3” pumps in the tunnel to resume the work on the rehabilitation.

The second obstacle was shortly after beginning the pour of the cell grout, there was significant leakage into the tunnel. TKT felt this was a result of the cell grout being so thin that it could fit between the liner plates. TKT added their expertise of offering to fill the remaining void space with a heavier grout that was a better option. The heavier grout was much more viscous than the cell grout, therefore, stopping any leakage through the liner plate joints. TKT overcame all obstacles for a successful completion of this emergency rehabilitation.