IGNACE – On Aug. 25, the Township of Ignace met with JML Engineering to finalize their investigation of the Pine Street culvert which has suffered some significant damage from the recent spring flooding.
JML Engineering inspection found over 10 holes in the two culvert barrels ranging up to 200 millimetres wide and 300 millimetres tall. Some of the voids measured behind holes were 500 millimetres deep. There were also zipper line tears near the waterline at both sides of the two barrels with a crack over 10 metres in length. Three of these cracks run directly beneath the road.
The investigator also reports that this level of deterioration “appears to have occurred over several years.”
At this point, due to the amount of deterioration, there is a strong possibility of collapse. Therefore, JML Engineering strongly recommends the closure of the Pine Street Bridge until repairs can be completed.
“There is a strong possibility of either a sudden collapse to a sidewall section at one of the culvert walls or a sudden settlement of the roadway above the culverts where voids of unknown size and location exist,” the JML Engineering report reads. “Any sudden drop due to the above would result in a sinkhole, which would be hazardous for any vehicle using the crossing at that time, or hazardous for a person walking across. Ongoing, future vehicle travel over this crossing will undoubtedly disturb the soils beneath, eventually causing the soil to leach out of the holes observed, and creating a sinkhole. Soil disturbance is made worse by heavy transports, and to a lesser degree cars and pickup trucks.”
The Township of Ignace has closed Pine Street Bridge to vehicle traffic as recommended, but pedestrians can still cross the footbridge.
“Pedestrian traffic may be able to use the existing concrete sidewalk at the site, as the sidewalk would offer some protection to bridge a sinkhole if one were to suddenly occur,” the JML Engineering report recommends. “However, this would require monitoring to ensure there are no progressions of settlement at the site, including probing the ground along the sidewalk to test for voids.”
The next step for Ignace’s Council is to calculate the cost of repair. Council has not yet determined the total cost, but discussion of the repair will come up in future council meetings.
The next scheduled meeting is on Sept. 19 at 6:00 pm.
