4504 BROADWAY 2025-03-24 - Laserfiche WebLink

City of Everett Permit Review EVERErr Status:Reviewed for Permit City of Everett 01/27/2024 9:46:15 AM Property Access Work Plan adjacent private properties(unless authorized by the private property owner), however traffic control may impact access to adjacent properties while explorations are being conducted. There will be multiple mobilizations to the site. Each of the major activities are described below in greater detail. Utility Locate(One Call) Prior to drilling, the boring locations will be marked, and the One Call service will be notified for utility locates. The boring locations will be recorded with a GPS unit. Representatives of each utility will then visit the site to mark underground utilities. This work will typically take place a week to 10 days before the drilling activities commence. Pavement Coring To minimize the extent of damage to the road pavement and prepare for the drilling activities,the concrete or asphalt pavement will be drilled through using a diamond-tipped pavement core barrel, 6 to 12 inches in diameter.After the core barrel drills through the pavement,the pavement core will be removed to evaluate the pavement layer ' N1,I thicknesses and subgrade soil conditions. Cuttings associated with the pavement coring will be vacuumed from the roadway during drilling or potholing. Vacuum Excavation (potholing) Utility potholing may be performed at select boring locations using vacuum excavation or air knife to excavate to a depth of 6 to 8 feet to check for unmarked or mismarked underground utilities at the proposed boring locations.The vacuum equipment utilizes a high-velocity air stream to penetrate, expand and break-up soil. The loosened chunks of soil and rock are then removed from the hole using a powerful vacuum. In this way a hole is created that reveals the buried utility.These n excavations are typically around 12 inches in diameter at the ground surface and will be backfilled and patched upon completion of the drilling activities. The potholing operation is typically performed utilizing a truck that is roughly 10' by 30' long, or by using a trailer mounted unit. Typical duration for utility potholing is 2-3 hours and may immediately precede the geotechnical drilling. Geotechnical Drilling The borings will be drilled using truck-or track-mounted drill rigs and are planned to be 20 to 100 feet deep(refer to Summary Table). The final s selected drilling locations will be accessed from public ROW. Each boring will be approximately 6 to 8 inches in diameter and will be advanced into the ground using either mud rotary or sonic drilling technique. For mud rotary drilling, the borehole is advanced through the soil using a rotary drill bit mounted at the end of drill rods. Drilling fluid is pumped down through the hollow rod string and rotary drill bit,where - it entrains drill cuttings and carries them to the surface as the drill mud _ flows upward to the surface. The drilling fluid and soil cuttings flow into .t ►__� . a tub where coarse drill cuttings are screened off for containment and disposal. Drill fluid is recirculated from a mud tub. Sonic drilling uses high frequency vibratory energy to advance a solid steel casing into the soil,with intermittent water injections as needed for lubrication. A sampler attached to the interior of the casing collects a highly disturbed continuous soil sample with each casing segment advance. Soil samples are brought to the surface using a wireline system and extruded into plastic bags for laboratory review and testing. For either method, soil samples will be obtained using Standard j Penetration Tests(SPT)at 2'/2-or 5-foot intervals to the depth explored.Work activities will be actively managed to minimize work area disturbance. Upon completion of each boring, all material generated ' during drilling operations will be stored in 55-gallon drums and removed offsite for disposal at a permitted facility by the drill crew. Each boring location will be backfilled according to Washington State Department of Ecology (Ecology)regulations using bentonite chips or bentonite-grout mixture.The boring location will be patched appropriately with concrete upon completion. SCHEDULE