HomeMy WebLinkAbout615 ROMA VALLEY DR - CORRESPONDENCE - 10/13/2000October 13, 2000
Project No: 1742-07-00
(ENGINEERINGHEAR
Mr. Leighton Campbell Ashcroft Homes RPORATION
4836 South College Avenue Suite 10
Fort Collins, Colorado 80525
Re: Lot 54, Miramont Valley P.U.D.; Fort Collins, Colorado
615 Roma Valley Drive
Dear Mr. Campbell,
Shear Engineering Corporation conducted foundation excavation observations for the above
referenced address on Wednesday, August 16, 2000. The soils noted at the bottom of the basement
excavation consisted primarily of weathered sandstone shale. The soils noted at the bottom of the
upper garage excavation consisted primarily of fill material. Excluding the fill, which was placed
with sitework development operations, the soils are generally consistent with those noted by Earth
Engineering Consultants in their subsurface investigation report titled, "Subsurface Investigation
Report, Proposed Miramont Future Addition, Fort Collins, Colorado"; E.E.C. Project No. 1932053;
report dated January 14, 1994.
Boring Logs B-4 and B-30 were the nearest borings taken to this site. Boring Log B-4 indicated
sandy lean clay to a depth of four feet (4'), underlain by highly weathered sandstone with claystone
zones for the remainder of the boring of twenty feet (20'). Boring Log B-30 indicated silty lean clay
with sand to a depth of three feet (3'), underlain by sandy lean clay to a depth of nine feet (9'),
followed by highly weathered silty sandstone to a depth of seventeen feet (17'), underlain by
weathered shale for the remainder of the boring of twenty feet (20').
Compaction testing was provided by Earth Engineering Consultants, Inc. during fill placement
operations at the time of sitework development. Copies of portions of the compaction test report data
as it relates to Lot 54, Miramont Valley P.U.D. are attached for reference.
A drilled pier (caisson) foundation system was recommended for this lot based on the Earth
Engineering Consultants subsurface investigation report noted above. At this time it was decided to
seek a second opinion on some alternative types of foundation systems that would be possible for
these soils conditions.
A second subsurface investigation report was prepared by Terracon titled, "Geotechnical Engineering
Report, Miramont Valley P.U.D., Lots 39 through 58, Roma Valley Drive and Roma Valley Court,
Fort Collins, Colorado"; Terracon Project No. 20005100; report dated June 8, 2000. Due to the
presence of the highly expansive sandstone shale in the basement excavation, and the increased
possibility of basement slab heave, over -excavation of four feet (4') was recommended in this
subsurface investigation report.
Over -excavation of four feet (4') was directed at the basement excavation, according to the
recommendations of the subsurface investigation report prepared by Terracon. Structural fill was
imported and placed in the over -excavated area in the basement allowing the foundation and
basement floor slab to bear on four feet (4') of non -expansive soil. Attached are portions of the
subsurface investigation report by Terracon titled, "Geotechnical Engineering Report, Miramont
Valley P.U.D., Lots 39 through 58, Roma Valley Drive and Roma Valley Court, Fort Collins,
Colorado"; Terracon Project No. 20005100; report dated June 8, 2000.
4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 220-5334 Fax (970) 282-0311 www.shearengineering.com
PAGE 2
October 13, 2000
Project No: 1742-07-00
Re: Lot 54, Miramont Valley P.U.D.; Fort Collins, Colorado
615 Roma Valley Drive
Boring Log No. 54, of the Terracon subsurface investigation report, was the boring taken on this site.
Boring Log No. 54 indicated sandy, lean clay fill material to a depth of five feet (5'), underlain by
sandy, lean clay to a depth of fifteen feet (15'), the bottom of the boring.
Following the over -excavation and backfilling, this lot is suitable for a spread footing foundation
system as recommended in the geotechnical investigation report by Terracon. The foundation plan,
which was prepared by Shear Engineering Corporation and dated March 2000, was used. Footings
were designed for a maximum allowable bearing capacity of 3,000 pounds per square foot (dead load
plus full live load) and a minimum dead load of 500 pounds per square foot.
Shear Engineering Corporation was present on Wednesday, September 27, 2000 for footing
construction observations. Shear Engineering Corporation was present on Wednesday, October 11,
2000 for wall steel placement observations. These observations were made to confirm that footing
construction and wall steel placement was completed in substantial compliance with the direction,
details and specifications noted on the foundation plan. And in substantial compliance with the
recommendations of the geotechnical investigation report.
All footing construction and wall steel placement was completed in substantial compliance with the
direction, details and specifications noted on the foundation plan and with the recommendations of
the geotechnical investigation report.
Groundwater was not evident in the excavation. Waterproofing is not required. At a minimum, all
foundation walls shall be dampproofed according to the requirements of the 1997 UBC, Appendix
Chapter 18, Waterproofing and Dampproofing Foundations. A foundation drain system will be
required. A sump pit to be located in the basement is recommended as a secondary drain outfall.
If you have any questions, please call (970) 226-5334.
Sincerely,
20262
Brian W. Shear, P.E.
Shear Engineering C
BWS / mad
attachments
cc: City of Fort Collins Building Department