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HomeMy WebLinkAboutNorth Mason Fiber Propane Storage - COM Engineering / Geo-Tech Reports - 6/20/2000 Id - GEO TECHNICAL ANALYSIS North Mason Fiber Company Prepared for: Mr. Robert Dressel North Mason Fiber Company P.O. Box 275 Belfair, WA 98528 H.L. Olson & Associates INC Engineering, Planning & Land Surveying SINCE. 10113 Prepared by: Norman L. Olson, P.E. N.L. Olson & Associates, Inc. 2453 Bethel Avenue Port Orchard, WA 98366 June 20, 2000 INTRODUCTION The North Mason Fiber Company is located near Belfair Washington in Mason County, west of and adjacent to Log Yard Road between State Highway 3 to the east and Old Belfair Highway to the west. The 25.56 acre site is situated in the NEl/4 of Section 21 , Township 23 North, Range 1 West, W.M., Mason County, Washington. The subject property is currently developed with a mixed land use of asphalt concrete pavement of varied depths, an office space, truck scales and one pond used for assembling and collecting fines from the logging chipping operation. A portion of the property is covered with some small firs, cedars and maples, etc., and some has been used in the past for operations by Warehouser and the soils have been disturbed, items buried, i.e.; stumps, logs, etc. DESCRIPTION / STATUS During the design of the storm, water and grading systems for North Mason Fiber Company, there has been quit a bit of excavation for implementation of the infiltration systems, plus soils investigation for infiltration design down into the 8' level. The findings of the excavations have been consistent throughout the site of a recessional outwash material that varies in depth from 6' — 8' it is a gravelly sand material that has been uniform in density and shows no sign of any water movement or transportation and is in most cases been fairly dry. The recessional outwash material overlays what is commonly referred to as glacial till. Till is a compact course gravel which has a binder of clay and silt. It is pretty much impermeable as far as water goes and has a very high bearing capacity. The soil survey for Mason County list this area as having an Everett series soils, which is a mixed sandy gravel of varied depth and is listed as a glacial till outwash material. It is a free draining material which lends itself to the infiltration systems designed for storm drainage control and has cobbles in varying sizes and the percentage of sand with those cobbles varies throughout tho site. The State of Washington in 1962 developed geological mapping through Kitsap and Mason Counties for the purpose of determining areas that could be used for implementation or areas where water could go from the surface to the aquifer without encountering a glacial till area. The North Mason Fiber Company's area is listed as Qvt which indicates that it is a glacial till area and in our experience we have found that this till layer is covered with 6' — 8' of the recessional outwash sands. 2 CONCLUSION The Cenex Corporation is planning to store three (3) large propane tanks along the west side of the North Mason Fiber Company site. The storage location is I adjacent to a railroad spur that will be used to transport the propane. The area is presently covered with asphalt concrete pavement and according to the Owner, Mr. Robert Dressel, this layer of asphalt concrete pavement is of more than average depth which I would assume to be more than 3" or 4" thick. N.L. Olson & Associates, Inc has designed and Ace Paving has placed over quite a bit of the site, a paving matt of 2" asphalt, 2" crushed servicing top course and a layer of gravel base which varies on the amount of course material that is already on the subgrade. Should the bearing of the tanks be within one (1) foot of the surface, it would be safe to assume a bearing capacity of 2500 pounds per square foot. With every foot gained in depth below the surface, one could add 500 pounds per square foot to that limit. Therefore, if the desired bearing capacity is 3500 square foot, the foundation of the tank should be approximately two (2) foot below the surface. N.L. Olson & Associates, Inc. does not advise simply anchoring the tanks to the existing asphalt concrete pavement. We are unsure at this point of the depth of that pavement because it has not been bored and prudent decision would be to excavate a couple of feet below the surface and to establish a firm base for the tanks at that point and therefore could use a 3500 pounds per square foot loading capacity. Should it be required, N.L. Olson & Associates, Inc. could do some soil testing at the exact location where the tanks are to be located, and establish depth of asphalt concrete pavement, density of the residual material and do compaction testing at those locations to establish an exact or better bearing capacity performance, this can be accomplished. p� ov WAS&., `r0 TNLm(-' a L. M on, P.E. �. sonssociates, Inc. r 1409'6 SIVX� - �ONAL l �'i 3 k � A N.L.Olson&Associates, Inc. Engineering, Planning and Land Surveying. July 18, 2000 Mr. Fred Benz Benz Engineering 942 NW 64t" Street Seattle, WA 98107-2218 (206)781-2113 / (206) 784-5107 Fax Re: North Mason Fiber Company Cennex Dear Fred: On Friday morning, July 14, 2000, we explored the asphalt and soil conditions where the tanks are proposed. Two holes exhibited the same condition. 1 . Six (6) inches of large aggregate asphalt concrete pavement. 2. Compacted gravel under the asphalt. The gravel was extremely dense and can support vertical loading in the neighborhood of 4000 pounds per square foot. I recommend the foundation to be at least one foot below the bottom of the asphalt. Feel free to call should you need additional information. Si er y, N rmaneE. .L. Olson ates, Inc. cc: Robert Dressel, North Mason Fiber Company 2453 BETHEL AVENUE, P.O. BOX 637, PORT ORCHARD,WASHINGTON 98366 (360)876-2284 FAX (360) 876-1487 •. �/ / (Seer hT (SEE DETAILS SHEET 7 do 8 5) 32 )N PON �A' I Y CEL• L 4 . TAIL$'-0N HE & OF..15)� ` EXTRUDED CURB BIOFILTRATION. SWALE `C (SEE DETAILS ON (SEE DETAIL`ON SHEET 10_OF 15) ' `•.1� .., _,'. SHEET 1 OF\15) 318ti MH 1 TYPE II 48"0 ✓x W STD. GRATE W/ GRAVEL BARRI R B ti� at1 SEE DETAIL AN A SHEET 10 OF 15) ENTIOWP.OND A,, ;ECOND CELL ADS N-12>.. S=1 �31¢ EX. EDGE OF PAVEMENT—- TO REMAIN f 5' GRAVEL LEVEL SPREADE AREA(TYP) A (TYP, SEE DETAILS ON SHEET 11 OF 15) W EXTRUDED CURB E B ----� (TYP) MH #2 TYPE II 4 "0 j, BIOSWALE STA 0+00 MH #3 TYPE II 48"0 BIOSWALE STA 0+00 I ` 20LF-36"0 CMP S=0.0% I.r��