HomeMy WebLinkAboutSOIL TEST REPORT - Eaglewood Enterprises - 700 S 300 E - Rezone from MDR to HDRHARPER - LEAVITT ENGINEERING, INC.
CIVIL & STRUCTURAL ENGINEERING, MATERIALS TESTING & LAND SURVEYING
985 N. Capital Ave. • P.O. Box 50691
Idaho Falls, Idaho 83405
(208) 524-0212
Fax (208) 524-0229
March 19, 2001
Mr. Keith Romney
Eaglewood Enterprises, LC
P:O. Box 58536
Salt Lake City, UT 84158
Re: Englewood Apartments
Dear Mr. Romney:
800 W. Judicial St. • P.O. Box 866
Blackfoot, Idaho 83221
(208)785-2977
Fax (208) 785-2990
In accordance with your request, Harper -Leavitt Engineering, Inc. has completed the laboratory
analysis on the two soil samples you delivered to our office last Thursday. We understand that
the soils were taken from test holes excavated on the subject property located on South 2' East
Street in Rexburg, Idaho. We further understand that the test holes exhibited silty material for
essentially the full depth to bedrock which was encountered approximately six feet below the
surface. Other information you provided us with verbally is that the proposed structures will
include three story wood frame apartments with brick veneer on the first story and the two soil
samples were from near the bottom of two separate test holes.
Anticipated footing loads for the apartments are in the range of 3-5 kips for perimeter footings and
up to 60 kips for interior column loads. Based on the soil classification, the allowable load
bearing capacity of the ML class silt is 1,000 psf. Using two feet of compacted structural fill
beneath the footings will provide an additional 1,000 psf for a total allowable bearing capacity of
2,000 psf. The fill material should consist of clean sandy gravel meeting a GP or GW
classification according to the Unified Soil Classification System. The material should not include
particles greater than 3 inches in any dimension and the percentage of material passing the #200
sieve (0.075 mm) should be less than five percent.
The structural fill placed beneath the footing elevation should be placed in 12 inch lifts and
compacted to a minimum of 95% of the maximum relative density as determined by ASTM
D1557. The fill must extend horizontally beyond the footings six inches for each foot of depth.
Using a 2 feet wide footing and two feet of structural fill, the fill must be four feet wide with the
footing centered on the fill. All fill should be approved by the geotechnical engineer of record
prior to hauling or placing the material.
Keith Romney
March 19, 2001
Page 2 of 2
Optionally the structures may bear on exposed unweathered bedrock. The basalt formation typical
of the Rexburg bench area is expected to have an allowable bearing capacity of 10 ksf. If bearing
on the bedrock, the depth of the formation must be verified to ensure that a thin shell of rock is
not underlain by lower strength soils. To accommodate subgrade inconsistencies, a minimum
footing width of 24 inches should be specified for all foundations regardless of loading. Each
structure should bear on only one soil type, for example, bearing a portion of the structure on
native silt and the remainder on structural fill is not recommended due to the increased potential
for differential settlement.
By limiting the total pressure on spread footings to the above recommended capacities, differential
settlement of footings should be in less than one-half inch and total settlement less than one inch.
Allowable load bearing capacities may be increased by 33% when considering wind or earthquake
forces acting alone or when combined with vertical loads. To provide for frost protection the
minimum earth cover from the bottom of the spread footings should be at least 36 inches. Buried
irrigation main lines and valves should be kept at least six feet from bearing walls.
An engineer from Harper -Leavitt Engineering should be contacted to observe the excavation and
foundation portions of the project to determine that actual conditions are compatible with those
considered for this report and recommendations. Placement of all fill and foundation soil should
be observed and tested to confirm that the proper density and depth has been achieved. Under no
circumstances should the footings be installed upon loose or saturated soil, sod, rubbish,
construction debris, frozen soil, non -engineered fill, or other deleterious materials, or within
ponded water. If unsuitable soils are encountered, they must be totally removed and replaced with
compacted structural fill. If granular soils become loose or disturbed, they must be properly re -
compacted before the footings are placed.
We appreciate the opportunity to provide consulting services on this project, if you have any
questions regarding our recommendations please contact me at our Idaho Falls office.
Respectfully Submitted,
HARPER-LEAVITT ENGINEERING, INC.
Ryan Loftus, PE
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800 W. Judicial St. • Blackfoot, Idaho 83221 / 985 N. Capital Ave. • Idaho Falls, Idaho 83405