2018.06.18 CC Minutes - Gravel Roads Workshop

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ra CITY OF Minutes HUGO CITY COUNCIL MEETING GRAVEL ROADS WORKSHOP EST.1906 HUGO CITY HALL wwwdhugonn.us00 14669 Fitzgerald Avenue North•Hugo,MN 55038 MONDAY,JUNE 18, 2018 —6 P.M. Call to Order Acting Mayor Petryk called the meeting to order at 6:02 p.m. PRESENT: Haas, Klein, Miron, Petryk, Weidt (arrived at 6:09) ABSENT: None ALSO PRESENT: City Administrator Bryan Bear, City Engineer Mark Erichson, Public Works Director Scott Anderson, WSB Engineering Mike Rief, and City Clerk Michele Lindau City Administrator Bryan Bear provided background reminding the Council about the discussion last fall regarding the condition of the gravel roads. Staff had been directed to communicate with residents on the roads that were not preforming up to standards and gather feedback. Staff had been working on a solution, and he introduced WSB Engineer Construction Services Manager Mike Rief. Rief provided background on himself stating he had worked with pavement type issues, with pavement design, and pavement and material forensics for over 20 years and has been with WSB for the last 13 years. He worked closely with Public Works Director Scott Anderson on identifying the roadways that were bad, and they reviewed the history and conditions present when the issues were occurring. Public Works Director explained that in 2007, all gravel roads went into the dust control program using modified Class 5 gravel, and the portion of small particles of silt and clay (i.e."fines") appeared to have increased. In 2010, it was observed that the roads became muddy, and in 2012, they increased to a"pudding" substance. The City has since added rock and sand to provide a temporary fix. Rief added that the problems seemed to occur after a rain event that followed a blading event. After blading, the roads become very permeable, and moisture remained on the road for an extended time. He felt the City's maintenance practices had been the proper ones. Test pits were dug in five different areas that showed the upper two layers had different composition. Some showed limestone that was very dusty, some showed course rock, but of most concern was three inches down where they found gravel that was stuck and bonded together. The binding component is foreign to aggregate surface roads. Silty soils will attract water, and there was also a high percentage of clay found that retains water. Layers with fines locked the water, and clay prevented the water from going down. Mike concluded there was a need to clean up the aggregate, modify the dust management, increase the slope where needed in a few places to maintain 4-6%, and incorporate compaction into the blading process to tighten the surface.