HomeMy WebLinkAboutLetter from Engineer 11.04.2014KURTZ & ASSOCIATES, INC.
5012 County Road 154
Glenwood Springs, CO 81601
STRUCTURAL CONSULTANTS
Phone (970) 945 6305
Fax (970) 945 1093
FIELD OBSERVATION REPORT
To: Garfield County Building and Planning Department
108 Eight Street
Glenwood Springs, Co.
Nov. 04, 2014
Re: ECOS Commercial Building: Inspection of Boulder Retaining Walls
6690 Highway 82, Garfield County, CO.
The building footprint is 40'-0" north -to -south by 103'-8" east -to -west. The
large, walk -out basement type structure building is a two story structure which occupies a
relatively steep site, north -to -south. Consequently, the floor -to -floor height from the
lower level to the main level is 14'-6". The lower level is a concrete slab -on -grade. Kurtz
& Assoc., Inc. is the structural engineer of record for the noted commercial building.
As structural engineer for the project, Kurtz & Assoc., Inc. issued documents
which detailed tiered boulder retaining walls on the east and west ends of the building.
Original details for the boulder wall were issued as part of the construction set for the
building (05/18/2012). We issued a set of 'in progress' recommendations on 08/20/2014.
Brian Kurtz, P.E., performed the following structural inspections during the course
of the boulder wall construction: 08/18/2014, 10/25/14 and 11/04/2014.
East Side of Building: The boulder wall on the east side of the building is a two
tiered wall: the upper tier is offset, in plan, 12'-0" from the lower tier. The lower tier is
approximately 6'-0" high and is constructed with two rows of boulders. The upper tier is
4'-0" to 6'-0" high, and is anchored at its base course with a 2'-8 ' high by 2'-8" deep by
approximately 7'-0" long boulder.
West Side of the Building: The boulder wall on the west side of the building is a
three tiered wall: the tiers align with the steps in the foundation wall of the building. The
lower, 3'-0" high wall aligns with the southwest corner of the building and is constructed
with primarily with a single course of 3'-0" high boulders. The center tier is 4'-0" high
and is offset 12'-0" from the lower course. The center tier extends approximately 23'-0"
west of the building and then turns to reinforce the slope above the existing drainage
channel. The center tier is constructed with 2'-0" high boulders. The upper tiers is
approximately 9'-0" high and is offset from the center tier approximately 10'-0". The
upper tier includes a number of oversized boulders 3'-0" high and greater. The largest of
these boulders are installed so that the long dimension of the boulder (Approximately
(2)
7'-0" maximum, are installed as "Headers" so that the long dimension extends back into
the retained soil mass). This installation technique significantly increases the overall
stability of the wall. Note that an area well was in place at the top of the upper tier.
/
West Side of the Parking Area: The upper tier on the west side of the building
extends to the north and borders the west side of the upper parking area (Parking on the
north side of the building). This section of wall, is, as constructed, an essentially
continuous wall of 15'-0" height. The wall is constructed with 2'-0" high and greater
boulders, and is laid back at a slope of approximately 2 -to -1 ((2) vertical to (1)
horizontal). This wall is structurally stable.
CONCLUSION:
At this time (As of 11/04/2014) the boulder retaining walls have been substantially
completed in a professional manner, and are structurally stable.
Kurtz & Associates, Inc.
/
/ Brian Kurtz, P.E.
/`072o/4