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Home My WebLink About841 Torino Cir - Special Inspections/Engineering - 11/22/20174396 GREENFIELD DRIVE WINDSOR, COLORADO 80550 (970) 545-3908 FAX (970) 663-0282 November 22, 2017 Columbine Health 14th Street, LLC 802 West Drake Road, Suite 101 Fort Collins, Colorado 80526 Attn: Mr. Bob Wilson (Bob.Wilson@columbinehealth.com) Re: Construction Observation and Testing – Submittal No. 6 Columbine Residences – Torino Circle Fort Collins, Colorado EEC Project No. 1174094 Mr. Wilson: As requested, during the period of October 23 through November 4, 2017, Earth Engineering Consultants, LLC (EEC) personnel provided construction observation and testing services for the proposed Columbine Residences project located at Torino Circle in Fort Collins, Colorado. Those services were provided on a part-time/on-call basis and included observations of foundation bearing subgrade soils for various buildings, observation and field density testing of building backfill material, observations of foundation reinforcing steel for various buildings, and testing of cast-in-place concrete for the referenced project. The results of the observation and testing services completed by EEC personnel during the referenced period are included with this report. Foundation Bearing Observations EEC personnel visited the site on October 25, 2017, to observe the foundation bearing subgrade soils for Building 10 / CE (839 and 841 Torino Circle). At the time of our site visit the foundation alignments had been excavated to approximate foundation bearing elevations, approximately 3 to 3½ feet below ground surface elevation. The bearing soils exposed at the bottom of the foundations alignments, in general, consisted of apparent native and/or engineered fill lean clay with variable amounts of sand. To evaluate the relative density of the apparent native and/or engineered fill lean clay with variable amounts of sand, a DCP was advanced an Earth Engineering Consultants, LLC EEC Project No. 1174094 November 22, 2017 Page 2 additional 30 inches below the exposed foundation bearing elevations. The DCP was advanced at two (2) random locations in the excavated foundation alignment areas. DCP testing indicated the lean clay with variable amounts of sand was stiff to very stiff in consistency. It is our understanding the upper 3 feet of site subgrade materials across the site were previously over excavated, moisture conditioned and replaced. The observation and testing of the removed and replaced overlot grading fill material was provided by Northern Colorado Geotech. Based on the results of the outlined field observations and testing for the referenced building, the bearing soils could be used for support of the footing foundations at the design maximum net allowable total load soil bearing pressure of 1,500 psf as recommended in our Geotechnical Exploration Report, EEC project number 1162080, dated September 8, 2016. Care should be taken during construction to avoid disturbing the subgrade materials. Materials that are loosened or disturbed by construction activities or materials that become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of reinforcing steel/concrete. Field Density Testing Services During the referenced period, EEC personnel performed field density tests on building backfill material as described herein, that was placed prior to and/or during our site visit. The field density tests were completed at random locations within the areas tested and were performed in general accordance with ASTM Specification D6938. The field density test results and approximate location of each test completed during the referenced period are shown on the attached summary sheet and associated site diagram. The field density test results conformed to the project specific compaction requirement of at least 95% of standard Proctor maximum dry density (ASTM D698) and were within ± 2% of the material’s optimum moisture content. Care should be taken during construction to avoid disturbing the subgrade materials. Materials that are loosened or disturbed by construction activities or materials that become dry and desiccated or wet and softened should be removed and replaced or reworked in place prior to placement of reinforcing steel/concrete. Earth Engineering Consultants, LLC EEC Project No. 1174094 November 22, 2017 Page 3 Foundation Reinforcement and UFER Observations During the referenced period, EEC personnel conducted site visits on October 23, 24 and 30, 2017, to perform visual observations of the reinforcing steel placed within Building 5 / DD (857 and 859 Torino Circle), Building 8 / AD (854 and 856 Torino Circle), Building 9 / FG (845 and 847 Torino Circle) and Building 10 / CE (839 and 841 Torino Circle) foundation elements at the gridlines and/or locations as identified on the enclosed “color-coded/highlighted” site diagrams. The horizontal and vertical reinforcement for cast-in-place foundation systems as indicated herein were completed in general accordance with the Spread Footing Schedule as presented on Sheet S1.1 for the various building plans, as well as the details presented on Sheet S2.1 of the project’s respective structural drawings. Clearances and lap lengths, where applicable, were checked and appeared to meet the minimum requirements. The horizontal and vertical reinforcement for the portions of the foundation systems as noted herein and observed by EEC personnel on the dates indicated, appeared to be in general accordance with details presented on the structural drawings prepared by Larsen Structural Design, dated February 24, 2017. Testing of Cast-in-Place Concrete During the referenced period, EEC personnel observed and tested Portland cement concrete delivered to the site for placement as indicated on the enclosed daily reports for the referenced project, (please refer to Set Nos. 10 and 11). Field testing performed on the plastic concrete included slump, air content, unit weight and concrete temperature. The ambient air temperature at the time of placement was also recorded. A minimum of five (4-inch diameter by 8 inches in height) concrete test cylinders were cast from representative samples on each respective date for laboratory curing and compressive strength testing. Results of the field, 7-day and completed 28-day laboratory compressive strength test results performed during the referenced period are included herein, while the 28-day laboratory compressive strength test results will be provided as they become available. Earth Engineering Consultants, LLC EEC Project No. 11 74094 November 22, 2017 Page4 We appreciate the opportunity to be of service to you on this project. If you have any questions regarding this report, or if we can be of further service to you in any other way, please do not hesitate to contact us. Very truly yours, Earth Engineering Consultants, LLC Jacob J. Silverman, P.E. Project Geotechnical Engineer Reviewed by: David A. Richer, P .E. Senior Geotechnical Engineer cc: Beacon Construction - Mr. Dillon Hinchley (dillon@beacon-con.com) Beacon Construction - Mr. Chris Mahlum (chris@beacon-con.com) Beacon Construction - Mr. Tyler Texeira (tyler@beacon-con.com) Proctor Designation A Maximum Dry Density (pcf) 108.0 Optimum Moisture Content (%) 16.5% Required Moisture Variance OMC +/-2% Required Percent Compaction 95% Laboratory Method ASTM D-698 Compliance with Project Specs Elev. / Lift No. Material (Proctor) Percent Moisture Dry Density Moisture (Pass / Fail) %Comp. (Pass / Fail) 27 10/27 1 Foundation Wall Backfill - See Diagram 0.0 A 16.2% 112.2 -0.3% 104% Pass Pass 28 10/27 2 Foundation Wall Backfill - See Diagram 0.0 A 18.1% 110.0 1.6% 102% Pass Pass 29 10/27 3 Foundation Wall Backfill - See Diagram 0.0 A 18.3% 108.6 1.8% 101% Pass Pass 30 10/27 4 Foundation Wall Backfill - See Diagram 0.0 A 18.1% 108.4 1.6% 100% Pass Pass 31 10/27 5 Foundation Wall Backfill - See Diagram 0.0 A 14.5% 109.7 -2.0% 102% Pass Pass 32 10/27 6 Foundation Wall Backfill - See Diagram 0.0 A 16.3% 110.4 -0.2% 102% Pass Pass SUMMARY OF FIELD DENSITY TESTS Location: Fort Collins, Colorado Project No: Date: 1174094 November 2017 EARTH ENGINEERING CONSULTANTS, LLC Approximate Test Location / Notes Daily Test Number Date Consecutive Test Number Moisture Variance Percent Compaction Field Test Results Project Name: Columbine Residences - Torino Circle Field Density Test Location Diagram Columbine Residences - Torino Circle - Fort Collins, Colorado EEC Project #: 1174094 Fill, Subgrade, & Aggregate Base EARTH ENGINEERING CONSULTANTS, LLC Reinforcing Steel Observation Diagram Building 5 / DD (857 & 859 Torino Circle) Columbine Residences - Torino Circle - Fort Collins, Colorado EEC Project #: 1174094 Date: November 2017 EARTH ENGINEERING CONSULTANTS, LLC Legend Stem Wall Reinforcement Observation 10-23-17 Reinforcing Steel Observation Diagram Building 8 / AD (854 & 856 Torino Circle) Columbine Residences - Torino Circle - Fort Collins, Colorado EEC Project #: 1174094 Date: November 2017 EARTH ENGINEERING CONSULTANTS, LLC Stem Wall Reinforcement Observation 10-13-17 Legend Footing Reinforcement Observation 10-5-17 Pilaster Reinforcement Observation 10-23-17 Pilaster Reinforcement Observation 10-30-17 Reinforcing Steel Observation Diagram Building 9 / FG (845 & 847 Torino Circle) Columbine Residences - Torino Circle - Fort Collins, Colorado EEC Project #: 1174094 Date: November 2017 EARTH ENGINEERING CONSULTANTS, LLC Footing Reinforcement Observation 10-13-17 Legend Stem Wall Reinforcement Observation 10-23-17 Reinforcing Steel Observation Diagram Building 10 / CE (839 & 841 Torino Circle) Columbine Residences - Torino Circle - Fort Collins, Colorado EEC Project #: 1174094 Date: November 2017 EARTH ENGINEERING CONSULTANTS, LLC Legend Stem Wall & Pilaster Reinforcement Observation 10-30-17 Footing Reinforcement Observation 10-24-17 Placement Date: Placement Location: Concrete Supplier: Water Added on Site: of Required 28 Day Compressive Strength (psi): B D D1 D2 Project Number: Bestway Beacon Construction - Mr. Dillon Hinchley (dillon@beacon-con.com) Beacon Construction - Mr. Chris Mahlum (chris@beacon-con.com) Beacon Construction - Mr. Tyler Texeira (tyler@beacon-con.com) 1174094 Report Distribution: Columbine Health Systems - Bob Wilson: Bob.Wilson@columbinehealth.com Project: Columbine Residences - Torino Circle 3510 10 11/20/17 28 45560 10 11/20/17 28 44120 8 4 12.57 Shear 8 4 12.57 Shear 3350 8 4 12.57 Shear 3630 3500 10 11/20/17 28 42110 10 10/30/17 7 30250 8 4 12.57 Shear 2410 2410 Failure Strength Strength Number Tested (days) (lbs) (in) (in) (in2) Type (psi) (psi) Specimen Date Age Applied Load Height Diameter Area Average Maximum Cylinder Cylinder Compressive Compressive ---- Comments: COMPRESSIVE STRENGTH OF FIELD CAST TEST SPECIMENS (ASTM C39/C31) Slump (in) ASTM C143 5.5" Air Content (%) ASTM C231 7.7% Unit Weight (pcf) ASTM C138 138.3 ---- Concrete Temperature (deg F) ASTM C1064 66 90° Max Air Temperature at Placement (deg F) 55 FIELD TEST DATA TEST RESULTS SPECIFICATIONS Comments: Yards: N/A N/A 3000 EEC Technician: AW Batch Time: N/A Sample Time: 11:00 AM Mix Code: N/A None Building 9 Foundation Walls and Building 8 Pilasters Bestway Type of Placement: Pump 10/23/2017 Test No.: 10 Ticket Number: N/A Truck Number: GENERAL INFORMATION N/A EARTH ENGINEERING CONSULTANTS, LLC REPORT OF CAST-IN-PLACE CONCRETE TESTS Placement Date: Placement Location: Concrete Supplier: Water Added on Site: of Required 28 Day Compressive Strength (psi): B Project Number: Aggregate Industries Beacon Construction - Mr. Dillon Hinchley (dillon@beacon-con.com) Beacon Construction - Mr. Chris Mahlum (chris@beacon-con.com) Beacon Construction - Mr. Tyler Texeira (tyler@beacon-con.com) 1174094 Report Distribution: Columbine Health Systems - Bob Wilson: Bob.Wilson@columbinehealth.com Project: Columbine Residences - Torino Circle 11 11/06/17 7 41220 8 4 12.57 Shear 3280 3280 Failure Strength Strength Number Tested (days) (lbs) (in) (in) (in2) Type (psi) (psi) Specimen Date Age Applied Load Height Diameter Area Average Maximum Cylinder Cylinder Compressive Compressive ---- Comments: COMPRESSIVE STRENGTH OF FIELD CAST TEST SPECIMENS (ASTM C39/C31) Slump (in) ASTM C143 4.5" Air Content (%) ASTM C231 5.3% Unit Weight (pcf) ASTM C138 141.6 ---- Concrete Temperature (deg F) ASTM C1064 63 90° Max Air Temperature at Placement (deg F) 23 FIELD TEST DATA TEST RESULTS SPECIFICATIONS Comments: Yards: 20 47 3000 EEC Technician: DM Batch Time: 8:13 AM Sample Time: 9:00 AM Mix Code: 5304122 None Stem Walls - Building 10 / CE Aggregate Industries Type of Placement: Pump 10/30/2017 Test No.: 11 Ticket Number: 60354798 Truck Number: GENERAL INFORMATION 9213 EARTH ENGINEERING CONSULTANTS, LLC REPORT OF CAST-IN-PLACE CONCRETE TESTS