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Home My WebLink AboutREDTAIL RESIDENTIAL - PDP - 26-01 - SUBMITTAL DOCUMENTS - ROUND 2 - GEOTECHNICAL (SOILS) REPORT (3)Ah LOG OF BORING NO. PZ-5 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Lagunitas Companies I SITE Cameron Park Second Filing PROJECT Fort Collins, Colorado Redtail Mixed Use Development SAMPLES TESTS Op J O O a DESCRIPTION 07 i 'L U _ _ Cn W w > Zco Z 4:w H Z U_ ZZ C s co d OU H O O c) Approx. Surface Elev.: 4989 ft o Z) Z c m n o 0 0. Le) 6" TOPSOIL 4988.5 WEATHERED SANDSTONE NTan, gray, moist, poorly cemented 2 4987 SANDSTONE Tan, gray, moist, cemented to well cemented 5 i 10 ". 12 4977 BOTTOM OF BORING 10-feet of 4-inch diameter PVC casing installed approximate Top of Casing Elevation = 4989.5 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerraccin BORING STARTED 7-8-02 DRY WD s 6 AB BORING COMPLETED 7 IWL WL 2 s RIG CME 75 1 FOREMAN ASR WL Water Level Checked on 7/17/2002 APPROVED DAR I JOB # 20015260 LOG OF BORING NO. PZ-4 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Lagunitas Companies SITE Cameron Park Second Filing PROJECT Fort Collins, Colorado L Redtail Mixed Use Development SAMPLES TESTS U DESCRIPTION p > F Lc z _ Cn w > zco [cw z zz Z o W-z > o LY L) Approx. Surface Elev.: 4989 ft w o m D z } t- of d� U) m a0 3 5 C� u o a, z� 5 cn 0.5 6" TOPSOIL 4988.5' SILTY CLAYEY SAND Brown, tan, moist, medium dense 2 4987 SANDSTONE Tan, gray, moist, cemented to well cemented 5 10 1 14 4975 BOTTOM OF BORING ' 10-feet of 4-inch diameter PVC casing installed approximate Top of Casing Elevation = 4989.5 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerracon BORING STARTED 7-8-02 WL `�- DRY WD 113 AB BORING COMPLETED 7-8-02 WL 2 RIG CME-55 FOREMAN ASR WL lWater Level Checked on 7/17/2002 APPROVED DAR I JOB # 20015260 LOG OF BORING NO. PZ-3 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Lagunitas Companies SITE Cameron Park Second Filing PROJECT Fort Collins, Colorado Redtail Mixed Use Development SAMPLES TESTS U' DESCRIPTION p c z w W z a- F rn m W o ?� wF Z Z0 OW w ( r w M� ¢O Ct Z1- 0 Approx. Surface Elev.: 4962 ft o Z) z of V) m 3: O o r- Z) co 0.5 6" TOPSOIL 4961.5 1 WEATHERED SANDSTONE 4961 Tan, ra moist poorly cemented I SANDSTONE Tan, gray, moist, cemented to well cemented s s 10 14 4948 BOTTOM OF BORING 10-feet of 4-inch diameter PVC casing installed approximate Top of Casing Elevation = 4962.5 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft irerracon BORING STARTED 7-8-02 WL ISZ DRY WD T 9.5 AB BORING COMPLETED 7-8-02 WL RIG CME-75 FOREMAN ASR WL Water Level Checked on 7/17/2002 APPROVED DAR I JOB # 20015260 LOG OF BORING NO. PZ-2 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Lagunitas Companies SITE Cameron Park Second Filing PROJECT Fort Collins, Colorado Redtail Mixed Use Development SAMPLES TESTS DESCRIPTION n > o a LU _ w Of W z Z U~ a _ a L > Q zUn �L �z > zZ OUX 0 Approx. Surface Elev.: 4964.5 ft o z d of Fp (n m o o. Z) ai =: `. 0.5 6" TOPSOIL 4964 WEATHERED SANDSTONE Tan, gray, moist, poorly cemented 2 4962.5 SANDSTONE Tan, gray, moist, cemented to well cemented 5 10 14 4950.5 BOTTOM OF BORING ` 10-feet of 4-inch diameter PVC casing installed approximate Top of Casing Elevation = 4965.0 The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerracon BORING STARTED 7-8-02 WL T DRY WD DRY AB ING COME BORMPLETD7ASR IT-7 Is RIG 75EFFOREMAN WL lWater Level Checked on 7/17/2002 APPROVED DAR I JOB # 20015260 Ah LOG OF BORING NO. PZ-1 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Lagunitas Companies SITE Cameron Park Second Filing PROJECT Fort Collins, Colorado Redtail Mixed Use Development SAMPLES TESTS DESCRIPTION chi > r5 o Na _ Q d U co c W O Z3 �FZ ow Approx. Surface Elev.: 4965.0 ft o Z) z } of (3 m 3 0 } 0 0- Z) Cn 0.5 6" TOPSOIL 4964.5 SILTY CLAYEY SAND Brown, tan, moist, medium dense 5 6 4959 SANDY LEAN CLAY Brown, tan, moist, stiff 9 4956 10 9.5 WEATHERED SANDSTONE 4955.5 Tan, aray, moist poorly cemented SANDSTONE Tan, gray, moist, cemented to well cemented 14 4951 BOTTOM OF BORING 10-feet of 4-inch diameter PVC casing installed approximate Top of Casing Elevation = 4965.5 The stratification lines represent the approximate boundary lines between soil and rack types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft 1rerracon BORING STARTED 7-8-02 WL 2 DRY WD 1 DRY AB CCME 7ASR WL GR1NG RIG 75EOMPLETDOREMAN WL lWater Level Checked on 7/1712002 APPROVED DAR I JOB # 20015260 r 1 a e � I a e• . , R7 1e1(L \ \� � - !I r I I I I I I i I f � I� � I J 6 XC • 6 XC�I I I I 1 II 11 24' l Fmnmrte Ome I 2w rD,. 7 i To Ise ' 9 1 1 5 I I �,I 11I I I I I I` "I it Icl I I I6 To Be All" B ®N0.1 NO.4 7 4 NO.1 B NO.6 NO.7 A ® TO Be s �� F 1�11�6 I��IIC C� � I iTo� 0.2 &(N ILL € < we r wys.,. ' NOA A a Tot $ N Derema, Faw NO.3 E ®5 N0.8 NO.9 01 U o�u®m, D ®e _N — L w Tmrepert Gran COinCbm � N0.5 ® 1 J-awe rrWcc vuoe FOSSIL CREEK FOSSIL CREEK OFFICE OFFICE F SSIL ORE N / OFFICE e LEGEND 0.11 0 \ REEK OFFICE PARK CORONADO COURT ®APPROXIMATE TEST BORING LOCATION assll OR ZONED C � ®TB NO. 2 NOT DRILIFD DUE TO o OFFICE �— PREVIOU5LY EXISTING TE5T BORINGS DUenban raw - _ TB N05. 14 2 DRILLED IN 1995, MC '-•"` I CAMERON 3 PROJECT NO. 20955185 ' 12 2 OS OFFICE CREEK O OFFICE I OFFICE w TEST BORINGS FOR 5 FOSSIL CREE W 12 O 1 OFFICE \ pS51L CREEK ( I ` I I ® SUPPLEMENTAL EXPLORATION k. OFFICE Ct TIMER COU14TY I e _ CAM&jON ORIW ZCNED FAi ' a Aad VACANT Q' S ,e rnyte � iE kT ap2d ri yp� 9 JL H 0 e c CAMERON `� \ OFFICE rR * •uar TBM=RIM RON CAMERON / CAMERON ' M � IS V�a4, MM oLe OFFICE / -�CAMERON .PARK OFFICE PARK OFFCE d 2 ^-r 0.14 9 u / ERON 15 OFFICE � \ XC N AMERI,--,/ \ 9aAt� OSSM CREW PARKTAY 4 OFFICE 3 I_ - I 20 Nphalt Onw / G0A FIGURE 1 : 51TE PLAN / EF REDTAIL MIXED USE DEVELOPMENT N 1 D�aaen r°"° I ' NORTH OF FOSSIL CREEK OFFICE PARK 4 WEST OF CAMERON PARK OFFICE I N .1 N .1 r� N N .2 ` / FORT COWNS, COLORADO Fro1eet Mngr: DAR Proms No. 200152GO a r rye. % Bha F th O C1.3 ECAERON EI I I Designed BY. DAR r` ra®n Snk: I ' = 100r \ Cna,echar CITY of FORT cowNs DAR 301 N. Howes Street Dab 7/ 18/02 LewS1INc WETLANDS REOTNLTNATURAL AREA l I — — �"� — —I — � ldd � DAR Fort Collins, Colorado 60521 Drawn By: SDG Rle DIAGRAM IS FOR GENERAL LOCATION ONLY, Name: 52GOFIG I fi9as No. I AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES Supplemental Geotechnical Engineering Report Lagunitas Companies — Redtail Mixed Use Development Fort Collins, Colorado Project No. 20015260 Page 4 Terracon The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations that may occur between borings, across the site, or due to the modifying effects of weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. The scope of services for this project does not include either specifically or by implication any environmental assessment of the site or identification of contaminated or hazardous materials or conditions. If the owner is concerned about the potential for such contamination, other studies should be undertaken. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, either express or implied, are intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others. In the event that changes in the nature, design, or location of the project as outlined in this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this report in writing. 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, TERRACON~� David A. Richer.P.E. Geotechnical Erig veer/Department Manager Enclosures: Sit-e-'p igure No. 1 Schematic from JR Engineering Log of Borings/Piezometer- Nos. 1 through 5 Copies: Addressee (3) JR Engineering (2): Mr. John E. Tufte, P.E. Supplemental Geotechnical Engineering Report Lagunitas Companies — Redtail Mixed Use Development Fort Collins, Colorado Project No. 20015260 Page 3 Terracon embankment fill materials should consist of relatively homogeneous material which is placed and compacted in uniform lifts, moisture conditioned to plus or minus 2 percent of optimum moisture content and mechanically compacted to at least 95 percent of Standard Proctor Density ASTM D698. It is our understanding the embankment slopes and/or surface area will not placed beneath any proposed structures, however the water district may be required to access the alignment for future maintenance purposes. Therefore, for stability purposes the material should be properly placed and compacted under typical structurally loaded conditions. It is also recommended the upper 6 to 8-inches eonsist of an aggregate base course material meeting CDOT Class 5 or 6 criteria, also placed and compacted to 95 percent of its Standard Proctor Density ASTM D698. The proposed embankments should be constructed on minimum slopes of 3:1 (horizontal to vertical) on both the upstream and downstream faces. After determining the type and/or borrow source material which is to used for construction of the slopes, and the design loads for the maintenance road portion, consideration should be given to running a slope stability analysis for the completed cross-section. Based on our understanding of the information presented to us via facsimile from JR Engineering, and assuming either on - site soils and/or approved imported material will be used to construct the embankments the slopes appear to be relatively stable. The roadway/street in -fill embankments, situated between the middle and southern detention ponds, as depicted on the enclosed schematic, should also be constructed using on -site soils and approved imported fill materials placed in accordance to the above mentioned recommendations. Additional pavement recommendations for this portion of the site have been provided in the original geotechnical engineering report on Page 8. It is our understanding the internal roadways are non jurisdictional City of Fort Collins roadways. Therefore, the recommendations for "main -traffic" corridors should apply to this section. If during final review this roadway is to be constructed in accordance to City of Fort Collins jurisdictional standards, a supplemental pavement evaluation will be required. General "earthwork" recommendations for the project pertaining to site and subgrade preparation, imported materials, placement and compaction criteria and excavation construction procedures are included in original report under the "Earthwork" section on page 11 through 13. Slope Protection The slopes of these two embankments should be protected from wave action, wind erosion and general weathering. It is recommended the face of the embankments be riprapped, consisting of a durable rock adequately sized. The riprap should be properly bedded with gravel or separated from the embankment by filter fabric to minimize the washing out of fines below the riprap. The top of the embankment slope should be provided with a minimum of 6 inches of gravel base course surfacing for future truck access. GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide testing and observation during excavation, grading, foundation and construction phases of the project. Supplemental Geotechnical Engineering Report Lagunitas Companies - Redtail Mixed Use Development Fort Collins, Colorado Project No. 20015260 Page 2 SOIL CONDITIONS Terracon The subsurface soils encountered at the site within the supplemental test borings/piezometers generally consisted of an approximate 6-inch layer of silty topsoil underlain by silty, clayey sand, sandy lean clay and/or weathered sandstone bedrock extending to the competent sandstone below. Weathered sandstone bedrock was encountered beneath the topsoil in Test Boring/Piezometer Nos. 2 and 3 and extended to the competent bedrock below. In the remaining test borings/piezometers sandstone bedrock was encountered at approximate depths of 2 to 9-feet below existing site grades and in all borings extended to depths explored, 15-feet. The stratification boundaries shown on the enclosed boring logs represent the approximate locations of changes in soil types; in -situ, the transition of materials may be gradual. The soil profile for this study is generally consistent with the soil and bedrock conditions presented in our previous subsurface exploration report. GROUNDWATER CONDITIONS Groundwater was encountered in the 3 of the most recently drilled test borings/piezometers at approximate depths of 6 to 13-feet below existing site grades or approximate elevations of 4952.5 to 4983.0, when checked 9 days after the drilling operations. The table below provides the approximate depth and elevation of groundwater encountered in each of the recently drilled test borings, including the existing water level elevations for the adjacent ponds. Test Boring/Piezometer No.. and/or Pond Approximate Depth to Groundwater, Ft. Approxlmate Ground. Surface Elevation ` Approximate Groundwater Elevation 1 Dry to 15-feet 4965.0 Deeper than 4951.0 2 Dry to 15-feet 4964.5 Deeper than 4950.5 3 9.5 4962.0 4952.5 4 13.0 4989.0 4976.0 5 6.0 4989.0 4983.0 North Pond - - 4985.5 South Pond - — 4955.5 These observations represent only the current groundwater conditions, and may not be indicative of other times or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, as well as volume of each pond. Based on the recent groundwater measurements obtained in each test boring/piezometer and water surface elevations of the existing detention ponds, it appears groundwater in the nearby borings is below the two ponds. Actual conditions may vary. Earthwork Embankment Recommendations for Waterline and Street Fill The civil engineering consultants for the project, JR Engineering of Fort Collins, Colorado, have requested Terracon to provide geotechnical engineering recommendations for earthen embankments for a waterline to be installed between the two most northern detention ponds as depicted in the attached schematic sent to Terracon via facsimile on July 23, 2002, Section A, and for a street "in -fill' at Section B. The waterline 6uIy_26—_200 Lagunitas Companies 3944 JFK Parkway Fort Collins, Colorado 80525 Attn: Mr. Jon Prouty o � Our JUL 2 9 2002 U Irerracon 301 N. Howes • P.O. Box 503 Fort Collins, Colorado 80521-0503 (970) 484-0359 Fax: (970) 484-0454 Re: Supplemental Geotechnical Engineering Report Redtail Mixed Use Development — Cameron Park 2nd Filing Southern Detention Pond and Waterline Between 2 Northern Ponds Fort Collins, Colorado Terracon Project No. 20015260 Terracon has completed a supplemental geotechnical engineering exploration for the above -referenced project located west of South College Avenue, south of Fairway Lane, and east of the Burlington Northern Railroad tracks in south Fort Collins, Colorado. The purpose of this additional exploration was to determine the soil, bedrock and groundwater profiles adjacent to the southern most detention pond to assist the wetlands consultant in his evaluation of the site, determine the profile adjacent to the northern most detention pond to assist the civil engineering design firm in their evaluation of the possibility of installing a waterline in this area and to provide earthwork recommendations for proposed waterline and street "in -fill" embankments. This study was conducted in general accordance with our Proposal No. D2001397B dated July 3, 2002. PREVIOUS EXPLORATIONS Terracon conducted a comprehensive geotechnical engineering exploration for the site in December of 2001, which consisted of drilling, logging, and sampling 19 test borings located throughout the site and providing recommendations for foundations, floor slabs, lateral earth pressures, pavement and general earthwork, based on the soil, bedrock and groundwater profiles and laboratory test results. For further information and findings thereof, please refer to our "Geotechnical Engineering Report" for the Redtail Development dated December 20, 2001, Project No. 20015260. FIELD EXPLORATIONS The supplemental site exploration, conducted on July 8, 2002, consisted of drilling 5 additional test borings to approximate depths 15-feet below existing site grades at locations as shown on the enclosed Site Plan, Figure No. 1, in an effort to provide soil, bedrock and groundwater profiles adjacent to the existing detention ponds, as previously mentioned. At the conclusion of the drilling operations, a 3-inch diameter PVC casing was installed in each boring for purposes of future groundwater monitoring. The additional test borings were advanced with a truck -mounted drilling rig, utilizing 4-inch diameter solid stem augers. The borings were located in the field by pacing from property lines and/or existing site features. Ground surface elevations at each additional test boring/piezometer were obtained by use of an engineers level and referenced to a benchmark consisting of the rim elevation of an existing Sewer Manhole as shown on the enclosed Site Plan, Figure No. 1. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used. Lithologic logs of each additional test boring/piezometer were recorded by the engineering geologist during the drilling operations. Groundwater measurements were made in each boring at the time of site exploration and when checked on July 17, 2002. 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