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Home My WebLink AboutPINNACLE TOWNHOMES - FDP - 34-00B - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTI Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 APPENDIX A Site Plan/Boring Location Diagram Test Borings/Piezometers APPENDIX B Laboratory Test Results APPENDIX C General Notes Pavement Preventative Maintenance Notes 1 1 IV Terracon TABLE OF CONTENTS Letter of Transmittal..........................................................................................Page No. ..............ge i INTRODUCTION.................................................................................................................1 PREVIOUS EXPLORATIONS.............................................................................................1 PROPOSED CONSTRUCTION.:........................................................................................ 2 SITEEXPLORATION.......................................................................................................... 3 FieldExploration......................................................................................................3 LaboratoryTesting..................................................................................................4 SITECONDITIONS.............................................................................................................4 Geology................................................................................................................... 5 SoilConditions...................................................................................................:.... 5 Field and Laboratory Test Results............................................................................ 5 Groundwater Conditions.......................................................................................... 6 ENGINEERING ANALYSES AND RECOMMENDATIONS.................................................6 Geotechnical Considerations...................................................................................6 FoundationSystems........................................................:....................................... 7 Basement Construction........................................................................................... 8 Lateral Earth Pressures...........................:...............................................................9 Seismic Considerations...........................................................................................9 Floor Slab Design and Construction........................................................................10 Pavement Design and Construction — for On -Site Parking Areas ...........................10 Earthwork................................................................................................................13 General Considerations...............................................................................13 SitePreparation...........................................................................................13 SubgradePreparation..................................................................................14 Fill Materials and Placement........................................................................14 Excavation and Trench Construction...........................................................15 Additional Design and Construction Considerations................................................16 Exterior Slab Design and Construction........................................................16 Underground Utility Systems........................................................................16 Corrosion Protection....................................................................................16 SurfaceDrainage.........................................................................................16 GENERALCOMMENTS.....................................................................................................17 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 to 5-1/2-feet below site grades. In an effort to lower groundwater levels throughout the site to allow for lower level construction, it is recommended an area underdrain system be installed. The area underdrain system should be placed in the sewer line utility trench and day light/gravity flow to the south toward Spring Creek. The individual units' interior perimeter drainage systems should be connected to the roadway underdrain system. ' Based on the type of construction proposed, and the anticipated maximum wall and column loads, it is recommended the proposed townhome structures be supported by conventional -type spread footings bearing on undisturbed subsoils and/or on engineered controlled fill. The footings should be placed a minimum of 3-feet above the maximum anticipated rise in groundwater and interior perimeter drains are installed and connected to the subsurface underdrain system. Based on our review of the proposed civil engineering drawings prepared by Shear Engineering Corporation, the proposed top of wall (T.O.W.) elevations vary from 4961 at the northwest comer and drop to approximately 4956 at the southeast corner. Assuming the basement footings will be placed approximately 8 to 9-feet below T.O.W. elevations, and correlating with the groundwater piezometric surface flow diagram, Figure 3, the footings will be 1-1/2 to 2-1/2 feet above existing _ water levels. Thus, with this close proximity, we recommend an area/subsurface drainage system be installed. Basement construction is considered feasible throughout the site provided lower level slabs are placed a minimum of 4-feet above the maximum anticipated rise in groundwater and interior perimeters drains are installed as previously stated. Slab -on -grade construction is feasible provided the recommendations set forth in this report are followed. Further details are provided in this report. We appreciate the opportunity to be of service to you on this phase of your project. If you have any questions concerning this report, or if we may be of further service to you, please do not hesitate to contact us. Sincerely, C i GIST • TER CON G�C.`:.'',K..R�cs • /12 David A. Riche P Geotechnical E anager SS10 N lk . Reviewed by: obe, P.E. Office Manger Copies to: Addressee (4) Shear Engineering, Corp. (1): Mr. Brian Shear October 10, 2001 Pinnacle Fort Collins, LLC C/o Anchor Development 1083 Wild Cherry Lane Fort Collins,. Colorado 80521 Attn: Mr. Russ Wells Irerracon 301 N. Howes • P.O. Box 503 Fort Collins, Colorado 80521-0503 (970) 484-0359 Fax: (970) 484-0454 Re: Geotechnical Engineering Report Proposed Pinnacle Townhomes South of Prospect Road, North of Spring Creek, and West of Lemay Avenue Fort Collins, Colorado Terracon Project No. 20015202 Terracon has completed a geotechnical engineering exploration for the proposed Pinnacle Townhome development project to be located south of Prospect Road, north of Spring Creek, and west of Lemay Avenue in Fort Collins, Colorado. This study was performed in general accordance with our Proposal No. D2001303 dated September 5, 2001 as well as the City of Fort Collins/Larimer County Urban Area Street Standards design criteria, dated January of 2001. Empire Laboratories, Inc., Terracon's predecessor, performed a geotechnical engineering explorations for the site in on July 1, and 2, 1985. For further information and findings thereof, please refer to our "Report of a Geotechnical Investigation" dated July 8, 1985, Project No. 6069- 85. The primary purpose of this study is to update the original geotechnical engineering report to and drill and install 5 groundwater piezometers in an effort to provide future monitoring of groundwater. This study is to supplement previous work provided at the site and will assist the project design engineer for an underdrain/subsurface drainage system, which may be required if basement construction is planned. The results of our engineering study, including the boring location diagram, laboratory test results, test boring records from the 5-additional test borings/piezometers, and the geotechnical engineering recommendations needed to aid in the design and construction of foundations, basement construction, subsurface drainage systems, pavements and other earth connected phases of this project are attached. The subsoils at the site consisted of sandy lean clay, silty clayey sand and silty sand with gravel extending to the bedrock below. Siltstone/sandstone bedrock was encountered in each of the 5 additional test borings at approximate depths of 10 to 13-feet below existing site grades and extended to the depths explored. Groundwater was encountered in each of the recently installed piezometers at approximate depths of 5 to 7-1/2-feet below existing site grades. In the previously drilled test borings in July of 1985, groundwater was encountered at approximate depths of 1-1/2 Arizona ■ Arkansas ■ Colorado ■ Georgia ■ Idaho ■ Illinois ■ lowaA Kansas ■ Kentucky ■ Minnesota ■ Missouri Montana ■ Nebraska \ Nevada ■ New Mexico ■ Oklahoma ■ Tennessee ■ Texas ■ Utah ■ Wisconsin ■ Wyoming Quality Engineering Since 1965 r rrJr' GEOTECHNICAL ENGINEERING REPORT PROPOSED PINNACLE TOWNHOMES ' SOUTH OF PROSPECT ROAD, NORTH OF SPRING CREEK, AND WEST OF LEMAY AVENUE FORT COLLINS, COLORADO TERRACON PROJECT NO. 20015202. OCTOBER 10, 2001 Prepared for. PINNACLE FORT COLLINS, LLC C/O ANHOR DEVELOPMENT 1083 WILD CHERRY LANE FORT COLLINS, COLORADO 80521 ATTN: MR. RUSS WELLS Prepared by: ITerracon 301 North Howes Street iFort Collins, Colorado 80521 � � lrerracon.J