HomeMy WebLinkAboutObservation of Excavation 12.18.2012HEPWORTH - PAWLAK GEOTECHNICAL
December 18, 2012
Carlos Cardenas
5910 West Washington Boulevard
Milwaukee, Wisconsin 53208
ccardeii a s 719 @gl ni ai I. coni
Hehworth-PakdakGeoreehnical, Inc.
5020 Cowin Road 154
Glenwood Springs, Colorado 51601
Phone: 970-945-7988
970-945.8454
niaiL hpgeo hpceorech.cnm
Job No. 112 277A
Subject: Observation of Excavation, Proposcd Barn, Lot 13, Homestead Estates,
2345 Homestead Road, Garfield County, Colorado
Dear Mr. Cardenas:
As requested by Kit Huggard, the undersigned representative of Hepworth-Pawlak
Geotechnical, Inc. observed the excavation at the subject site on October 31, 2012 to
evaluate the soils exposed for foundation support. The findings of our observations and
recommendations for the foundation design are presented in this report. We previously
conducted a subsoil study for design of foundations at the site and presented our findings
in a report dated August 31, 2012, Job No. 112 277A.
The proposed barn will be a 40' by 60', one-story steel frame structure with metal siding.
The floor will be slab -on -grade. Foundations consist of pad footings and were designed
for an allowable soil bearing pressure of 1,200 psf as provided in our previous report.
At the time of our visit to the site, the ten pad footing foundation excavations had been
cut from 3 to 5 feet below the adjacent ground surface. The soils exposed in the bottom
of the excavation consisted ofbasalt cobbles and boulders in a sandy clay to sandy silt
matrix. No free water was encountered in the excavations and the soils were slightly
moist.
The northern two thirds of the slab subgrade consisted of natural subsoils suitable for
support of the proposed concrete slab. The southern third of the slab subgrade consisted
of on-site fill which contained organics including roots. We recommended to Kit
Huggard to remove the organic soils from the southern part of the slab subgrade and
moisten and compact the remaining soils to at least 95% of standard Proctor density for
support of the proposed slab. As an alternative, imported 34 -inch road base could be used
as structural fill below slab areas.
The soil conditions exposed in the pad footing excavations are consistent with those
previously encountered on the site and suitable for support of spread footings designed
for the recommended allowable bearing pressure of 1,200 psf. Loose and disturbed soils
should be removed in the footing areas to expose the undisturbed natural soils. Other
Parker 303-841-7119 Colorado Springs 719-6.33-5562 Silverthorne 970-468-1989
Carlos Cardenas
December 18, 2012
Page 2
recommendations presented in our previous report which are applicable should also be
observed.
The recommendations submitted in this letter are based on our observation of the soils
exposed within the foundation excavation and the previous limited subsurface exploration
at the site. Variations in the subsurface conditions below the excavation could increase
the risk of foundation movement. We should be advised of any variations encountered in
the excavation conditions for possible changes to recommendations contained in this
letter. Our services do not include determining the presence, prevention or possibility of
mold or other biological contaminants (MOBC) developing in the future. If the client is
concerned about MOBC, then a professional in, this special field of practice should be
consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
HEPWORTH — PAWLAK GEOTCHNICAL, INC.
Daniel E. Hardin, P.E.
Rev. by: SLP
DEH/ksw
cc: Accurate Steel Structures — Kit Huggard kithuggardftmail.com
Job No. 112 277A