MODIFICATION
Y -- Ames Gulch Retaining Wall
- Notice Date
- 8/22/2012
- Notice Type
- Modification/Amendment
- NAICS
- 237990
— Other Heavy and Civil Engineering Construction
- Contracting Office
- Department of Agriculture, Forest Service, R-2 Rocky Mountain Region, 740 Simms Street, Regional Office, Golden, Colorado, 80401
- ZIP Code
- 80401
- Solicitation Number
- AG-82X9-S-12-0160
- Archive Date
- 9/21/2012
- Point of Contact
- Jay Tobin, Phone: 9708746625
- E-Mail Address
-
jtobin@fs.fed.us
(jtobin@fs.fed.us)
- Small Business Set-Aside
- Total Small Business
- Description
- Ames Gulch Retaining Wall, Additional Q&A 1. At the site visit we saw a previously installed retaining wall above the site of the proposed wall. According to the plans the embedment on the proposed wall is 13'. The distance from the face of the existing wall, to the face of the proposed wall is less than 6'. When we excavate 15' down we risk undermining the existing wall. If we were able to excavate a vertical cut 15' down and add the batter of the wall we still only end up with around 8.5' of embedment. Has the existing wall been taken into consideration? Yes, the existing wall has been taken into consideration; we do not want to undermine any of the existing wall. The required lengths of geogrid shown on sheet 4 of 5 do not indicate embed width. What is indicated is the minimum sheet length estimated to attach to the face timber, lay out and envelope the fill. Utilizing the dimensions noted on sheet 5 of 5, with a minimum 2' top lap and 12" back wall rise, a 10' embed (or bottom excavated width) would be expected. With a 3' tread, that would place the toe at minimum 13' from the upper wall toe, still less than the 14.5' horizontal that you indicate above. 2. According to the plans "Geogrid for the base and alternating layers (full width Layers) shall be installed with Rib direction parallel to the wall face (when deployed the roll shall be perpendicular to the wall face)." The roles of geogrid are 13.1 feet wide creating a seam prior to the rise and back lap. After adding the embedment the rise and back lap we end up with a length of 16'. Is there a minimum required overlap to account for this seam? Per Section 259, Reinforced Soil Embankments, Section 259.03, paragraph 2, "Do not splice reinforcements in the primary direction. Geogrids may be overlapped three ribs (approximately 1 inch) in the direction transverse to the primary direction, and may be held together with hog rings or other approved devices." Also, see comments from #1 above regarding "L" Required Geogrid Lengths. 3. At the site visit we encountered several existing walls. Is there any information as to the soils composition encountered while constructing those walls, specifically was bedrock encountered? There is no information available regarding bedrock from the previous wall construction.
- Web Link
-
FBO.gov Permalink
(https://www.fbo.gov/spg/USDA/FS/82X9/AG-82X9-S-12-0160/listing.html)
- Place of Performance
- Address: Galloping Goose Trail, San Miguel County, Colorado, United States
- Record
- SN02851396-W 20120824/120823001846-2635ff9d4b53f08716f9ac82d2b5f933 (fbodaily.com)
- Source
-
FedBizOpps Link to This Notice
(may not be valid after Archive Date)
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