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HomeMy WebLinkAboutTHE MARKET PLACE PUD - PRELIMINARY - 21-89 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGeotechnical' Consultants, Inc. Loft. '.-i: y APR 0 4 19b"i April 4, 1989 Rosenbaum -Dean \N111-1 VAKE_IA. V.G. 101 North Cascade, Colorado Springs, CO 80903 Attn: Mr. Steve Boyette Re: Fort Collins Phar-Mor Shopping Center Preliminary Soil Information Dear Steve: GCI has completed a subsurface soil investigation at this project site. On March 31, 1989, eleven test borings were drilled across the parcel of ground occupying the northeast corner of South College Avenue and Troutman Parkway. It is my understanding that a preliminary development plan will be submitted shortly to City officials. while precise engineer- ing evaluation and interpretations cannot be provided at this date since laboratory testing is still in progress, we can pro- vide some information regarding this construction and the suit- ability of the site in general. Our reconnaissance of the property indicates that a considerable portion of the site is in a disturbed condition. This fact is supported by aerial photographs covering the last 25 years. Dis- turbance has resulted from past development of the property (for ranching and residential use) and apparently from mass wasting of soil materials from area development projects. At least two areas of well defined man -placed fill can be found across the subject site. The test boring information indicates that shallow bedrock will be encountered beneath the northern portions of the site. Bed- rock can be expected in this area at depths ranging from 5 to 10 feet below the existing ground surface. The bedrock drops sharply in a southerly direction with bedrock in the middle of the main anchor tenant being found at a depth of about 30 feet. The bedrock consists of. siltstone, sandstone, and very sandy shale. The soil materials The fill materials the upper several "stiff" condition, depths of 10 to higher moisture. across the property are silty and sandy clays. are of similar composition. The soil within feet of the profile is in a low moisture, forming a crust across the job site. Below 15 feet the soil becomes much softer and of 7750 N. Union Blvd., Suite 105 Colorado Springs, Colorado 80920 (710) 528.1331 • • Rosenbaum -Dean April 4, 1989 Paqe -2- In the northern shallow bedrock area,, free water was not inter- sected by the test borings. However, beneath the majority of the southern portion of the site, free water can be found at about 15 feet below existing grade at this time. Indications are that fluctuations of the groundwater table of +5 feet can be expected at this location. Given the type of subsurface conditions observed, our preliminary assessment indicates that drilled piers might be necessary because of fears over long-term differential movement. This settlement would result from either consolidation of the soft, underlying clay, or from pre-existing fills associated with past land usage. Further information regardinq the type of foundation system cannot be provided until such time as the laboratory test- ing has been completed. Based upon our assessment of site history, as supplemented by the subsurface soil investigation program, we believe that the pro- posed site can be developed as planned. Special attention should be focused on foundation stability/settlement and pavement design/construction. A formal geotechnical report will be issued shortly by GCI which covers these items and provides additional detailed design and construction recommendations for the several buildings proposed. If you have any questions regarding our preliminary assessments and recommendations, feel free to contact us. Respectfully submitted, GEOTECHNICAL CONSULTANTS By: Martin F. Essigma MFE/heh GCI Job No. 3389 16451 POE. 44 IE cc: Yergensen, Obering, and Whittaker, Attn: Mr. Gene Yergensen