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HomeMy WebLinkAboutCSU HEALTH CENTER / GF WAIRDS REPLAT & UTILITY PLAN - PDP/FDP - FDP150039 - SUBMITTAL DOCUMENTS - ROUND 1 - EROSION CONTROL LETTER/REPORTEROSION CONTROL REPORT FOR CSU HEALTH AND MEDICAL CENTER AT 151 W. LAKE STREET FORT COLLINS, CO 80524 PREPARED FOR COLORADO STATE UNIVERSITY Fort Collins, CO 80523 NOVEMBER 11, 2015 CSU Health and Medical Center - Erosion Control Report Page 1 of 10 ABLE OF CONTENTS SECTION 1 – GENERAL LOCATION AND DESCRIPTION ................................................................. 2 SITE LOCATION .................................................................................................................... 2 DESCRIPTION OF PROPERTY .................................................................................................. 2 SECTION 2 – DRAINAGE BASINS AND HISTORIC RUNOFF .............................................................. 2 HISTORIC BASINS ................................................................................................................. 3 PROPOSED DEVELOPED BASINS ............................................................................................ 3 SECTION 3 – STORMWATER POLLUTION PREVENTION ................................................................... 4 TEMPORARY EROSION CONTROL .......................................................................................... 4 PERMANENT EROSION CONTROL........................................................................................... 4 STORMWATER MANAGEMENT CONTROLS .............................................................................. 4 SEQUENCE OF CONSTRUCTION ACTIVITIES .............................................................................. 7 SECTION 4 – CONCLUSIONS ..................................................................................................... 9 SECTION 5 – REFERENCES ....................................................................................................... 10 APPENDIX APPENDIX A – UTILITY PLANS 1. EROSION CONTROL PLAN (CE1.0) 2. SWMP AND EROSION CONTROL DETAILS (CE1.1-1.2) 3. OVERALL GRADING PLAN (C1.0) 4. DETAILED GRADING PLANS (C1.1-1.6) APPENDIX B – EROSION CONTROL ESCROW/SECURITY CALCULATIONS APPENDIX C – SOIL DATA FROM CTL THOMPSON CSU Health and Medical Center - Erosion Control Report Page 2 of 10 SECTION 1 – GENERAL LOCATION AND DESCRIPTION SITE LOCATION The Colorado State University (CSU) Health and Medical Center (Medical Center), is located at 151 West Lake Street in the City of Fort Collins, Colorado. DESCRIPTION OF PROPERTY The site is owned by Colorado State University. The site is approximately 5.7 acres of developed residential properties with an alley bisecting the lot from north to south. The site currently drains in several directions with most of the flow directed to the south with slopes from 1.9% to 2.5% and east at a slope of 1.2% to the intersection of Prospect Road and College Avenue. A smaller portion of the site drains to the north at a 2.0% slope to Lake Street and to the west at a slopes ranging from 1.8% to 3.8% to Mason Street. From the geotechnical report dated August 18, 2015 the soil is mainly sandy clay with areas of gravely sand and existing fill. Sandstone bedrock was encountered at 18ft to 24ft below the ground surface with ground water being located at 12ft to 19ft below ground surface. The existing percent imperviousness of the property is approximately 31.3%. Type C soil was used for the rational calculations. The rainfall erodibility is K=0.24 for type C soil and will cause rilling and gulling over longer distances and steeper slopes. Perimeter control will be the primary means of minimizing the extent of gulling. There are no irrigation canals passing through the site. According to the FEMA Flood Insurance Rate Map Panel Number 08069C0979H dated 05/02/2012, the site is located outside of the 100-year floodplain area. CSU Health and Medical Center - Erosion Control Report Page 3 of 10 SECTION 2 – DRAINAGE DESIGN HISTORIC CONDITION The existing system was modeled in SWMM by Ayres Associates for the CSU Medical Center Project Drainage Memo dated July 30, 2015. The Ayres SWMM model was used for the existing system analysis. See the Final Drainage Report for the results of the Ayres SWMM. The site was divided into six historical basins. One basin drains to the north into Lake Street and is collected by inlets on Lake Street. A second basin drains to the east onto College Avenue. The flow then travels south along College Avenue until it turn west onto Prospect Road which has a set of sump inlets approximately 50ft west of College Avenue. The third and fourth basins drain to the west on the Mason Street Outfall (MSO) where inlets on the MSO collect the flow. The last two basins drain south onto Prospect Road where there is a set of sump inlets. Currently the pipe system that the Prospect Road inlets tie into is undersized and ponding occurs for larger storm events. There is no existing onsite detention for the site. DEVELOPED CONDITION The developed drainage basins will not drastically alter the historical drainage paths, but do decrease the peak flow rates. Flow to the Lake Street inlets decrease from 6.44cfs to 0.47cfs with the installation of two inlets on the north and south sides of Lake Street. Flow to College Avenue decreases from 8.82cfs to 1.86cfs with the addition of area drains in the plaza area and an inlet on College Avenue. The inlet on College Avenue will be able to capture 3.52cfs, restricted by the downstream 12inch pipe, which is more than the estimated runoff from the northeast undeveloped portion of the site at 2.66cfs. Only a small portion of the site now flows onto Prospect Road, the flow decreases from 20.48cfs to 4.06cfs. The proposed total 100-year peak runoff for the site is 51.0cfs with only 6.39cfs of that flow not being captured and conveyed to the detention pond. The detention pond has a release rate of 10.76cfs. Therefore, the total flow off the site from the detention pond and the non-captured flow is 17.15cfs. The existing site has a peak 100-year runoff rate of 44.66cfs. In the event that the detention ponds outlet pipe is clogged and the pond overflow the water will drain into Prospect Road and flow east towards College Avenue and the Prospect Road inlets. There will be no water quality control in the detention pond because it will be controlled in the MSO’s regional detention pond. The development of the site will allow for all but 6.39cfs of runoff from the site to be captured in the detention facility and reduce the runoff that currently flows offsite. At this time the existing three properties on the northeast edge of the site will not be developed. However, in the future the properties may be purchased by CSU and developed. The current storm system and detention pond was sized to allow for the addition of this parking lot. CSU Health and Medical Center - Erosion Control Report Page 4 of 10 SECTION 3 – STORMWATER POLLUTION PREVENTION TEMPORARY EROSION CONTROL A temporary erosion control plan is to be implemented for the site during construction. Temporary erosion control measures include, but are not limited to, slope and swale protection provided by the use of erosion control wattles/sediment control logs, rock socks, erosion control blankets, and sedimentation basins, etc. All temporary erosion control measures are to be removed after they are deemed unnecessary. A general erosion control plan has been provided in Appendix A. PERMANENT EROSION CONTROL Chapter 2 of the Urban Drainage and Flood Control District’s Urban Storm Drainage Criteria Manual Volume 3 (USDCM) provides guidelines for the selection of appropriate permanent structural BMPs for a site that is to be developed or redeveloped. The Medical Center is best characterized as a “conventional redevelopment” with over 1 acre of impervious area on the project site. The BMP decision tree for such sites is provided in Figure 2-2 of the USDCM. As previously stated, the site and surrounding vicinity is comprised of hydrologic soil group Type C soils, per the NRCS soil survey, with a depth to bedrock of greater than 5 feet. As stated by Shane Boyle with the City of Fort Collins, if the site remains a CSURF property then the City’s low impact development (LID) and paver standards must be met. Since the entire site will be CSU property, the LID and paver criteria is not required. The meeting minutes and notes are attached in Appendix A. The MSO system includes 0.25acre-ft of water quality capture volume (WQCV) for this site in the regional detention pond. This site has a WQCV of 0.129acre- ft. Therefore, no water quality control is required on site. The minor storm event was also not controlled on site and the system was designed to capture and convey the 100-year event with flooding. STORMWATER MANAGEMENT CONTROLS The Stormwater Management Plan (SWMP) administrator will be determined at the time the project is bid for construction. According to the CDPHE Stormwater Fact Sheet – Construction, construction activities produce many different kinds of pollutants which may cause stormwater contamination problems. The main pollutant of concern at construction sites is sediment. Grading activities remove grass, rocks, pavement, and other protective ground covers, resulting in the exposure of underlying soil to the elements. The soil is then easily picked up by wind and/or washed away by rain or snowmelt. In addition, construction activities often require the use of toxic or hazardous materials such as fuel, fertilizers, pesticides, and herbicides, and building materials such as asphalt, sealants, and CSU Health and Medical Center - Erosion Control Report Page 5 of 10 concrete, which may also pollute stormwater. These materials can be harmful to humans, plants, and aquatic life. There are no other known potential pollution sources. However, this condition should be confirmed by the owner/operator or SWMP administrator. Other pollution sources that could be present include: runoff from vehicle washing, vehicle maintenance and/or fueling, There are no known existing non-stormwater components of discharge (i.e., springs, landscape irrigation return flow, and etc.), or any anticipated during construction. 1. All Disturbed and Stored Soil: The total disturbed area will be approximately 5.7 acres. Soil stockpiles should be kept below the locally mandated maximum height of 10 feet and surrounded with sediment control devices. If the storage of these soils occurs over a period greater than 30 days, then consider temporarily seeding the soil to minimize soil loss to wind and water erosion. 2. Vehicle Tracking of Sediments: The existing site is developed residential properties with a bisecting gravel/asphalt alley. A temporary stabilized stone pad and/or Trackout Plate (Vehicle Tracking Control pad, VTC) will be provided at points of ingress and egress onto the unpaved area. The VTC is designed to reduce the amount of mud transported onto the public roads by construction traffic. If the site is extraordinarily muddy, then consider designating an area to wash construction vehicles before they leave the site and enter the public right-of-way. A BMP such as this is a good way to avoid the costs associated with street cleaning or accidentally discharging large amounts of sediment into other storm drain systems. When in doubt, choose methods that prevent pollution rather than ones that force clean-up at the downstream end just before the stormwater enters the receiving waters. In other words, the most efficient construction site BMPs are those that prevent erosion from happening. 3. Inlet Protection (IP): gravel inlet protection will be used on all existing downstream inlets to prevent sediment and debris from entering the storm drain system. 4. Street sweeping will be conducted as necessary to remove sediment tracked on to pavement and adjacent streets. 5. Management of Contaminated Soils: There are contaminated soils on site and have been mitigated using a clay liner above the contaminated soils. All grading and construction activities will be conducted above the depth of the clay liner and the contaminated soils will not be disturbed. If additional contaminated soils are found, the contractor shall report to the SWMP administrator. 6. Loading and Unloading Operations: CSU Health and Medical Center - Erosion Control Report Page 6 of 10 The existing entrance to the site is currently paved and loading/unloading activities will occur within the paved area of the site or a temporary gravel staging area will be provided. 7. Outdoor Storage Activities: Materials storage, waste disposal, and vehicle maintenance and fueling can occur within an enclosed and secure area. 8. Vehicle and Equipment Maintenance and Fueling: Materials should be stored and handled in covered areas to prevent contact with stormwater, and chemicals should be stored within berms or secondary containment devices to prevent leaks and spills from entering stormwater runoff. Spill Management In general, spill prevention and response should include the following: a) Notification procedures to be used in the event of an accident. At the very least, the SWMP Administrator should be notified. Depending on the nature of the spill and the material involved, the Colorado Department of Health, downstream water users, or other agencies may also need to be notified. b) Instructions for clean-up procedures. c) Provisions for absorbents are to be made available for use in fuel areas, and for containers to be available for used absorbents. d) Procedures for properly washing out concrete trucks and other equipment in a manner and location so that the materials and wash water cannot discharge from the site, and never into a storm drain system or stream. 9. Significant Dust or Particulate Generating Processes: Disturbed areas not yet ready to be seeded, landscaped, paved, or otherwise stabilized shall be watered, or ripped as necessary to preclude visible dust emissions. Contractor shall make every effort to minimize particulate emissions from vehicles performing the work, including but not limited to regular maintenance of construction equipment. 10. Routine Maintenance Activates Involving Fertilizer, Pesticides, Detergents, Fuels, Solvents, Oils, Etc: Materials should be stored and handled in covered areas to prevent contact with stormwater, and chemicals should be stored within berms or secondary containment devices to prevent leaks and spills from entering stormwater runoff. 11. On-site Waste management Practices (Waste Piles, Liquid Wastes, Dumpsters, etc): Materials storage, waste disposal, and vehicle maintenance and fueling can occur within an enclosed and secure area. The area can be enclosed with temporary fencing and accessed through a gate with a lock. 12. Concrete Truck/Equipment Washing: CSU Health and Medical Center - Erosion Control Report Page 7 of 10 A concrete washout facility will be provided onsite. Properly wash out concrete trucks and other equipment in a manner and location (a minimum of 50 feet away from any inlet structures) so that the materials and wash water cannot discharge from the site, and never into a storm drain system or stream. 13. Dedicated Asphalt and Concrete Batch Plants: There will be no dedicated batch plant on site. 14. Non-Industrial Waste Source Such as Workers Trash And Portable Toilets: Garbage cans shall be located at break areas and portable toilets shall be provided if onsite bathroom facilities cannot be used. Locate dumpsters and portable toilets away from drainage courses (minimum 50 feet from any inlet structures) and stake down toilets to prevent tipping. 15. Other Areas or Procedures where Potential Spills can Occur: Records of spills, leaks, or overflows that result in the discharge of pollutants must be documented and maintained. Record all spills that are responded to, even if they do not result in a discharge of pollutants. Information that should be recorded for all occurrences includes the time and date, weather conditions, reasons for the spill, etc. Some spills may need to be reported to immediately. Specifically, a release of any chemical, oil, petroleum product, sewage, etc., which may enter waters of the State of Colorado (which include surface water, ground water and dry gullies or storm sewers leading to surface water) must be reported. More guidance is available on the web at www.colorado.gov. The Division’s toll-free 24-hour number for environmental hazards and chemical spills and releases is 1-877-518-5608. SEQUENCE OF CONSTRUCTION ACTIVITIES Construction Start Date (This is the day you expect to begin disturbing soils, including grubbing, stockpiling, excavating, demolition, and grading activities): January 1, 2016. Final Stabilization Date (this is when the site is finally stabilized. This means that all disturbed areas have been either built on, paved, or a uniform vegetative cover reaching over 70% of the initial vegetative density has been established.) Even if you are doing one part of the project, the estimated completion date must be for the overall project: June 2017. Construction Sequencing: (Detailed construction sequencing to be determined by the contractor) 1. Installation of temporary erosion and sediment control measures. This includes all sediment control logs, rock socks, erosion control blankets, and silt fence where all land disturbing activities will occur. 2. Sequence of all land disturbing activity. Overlot grading in preparation for the pouring of new sidewalks will occur early in the construction schedule. Additional land disturbance will occur around the site for utility installation and the construction of the new bandstand/stage structure. 3. Drainage facility construction. CSU Health and Medical Center - Erosion Control Report Page 8 of 10 No new drainage facilities are proposed for this project. 4. Sediment basins, temporary channel stabilization. Sediment control logs or erosion control blankets will be installed on the banks of the vegetated detention pond and swale on the west part the site. 5. Seeding All disturbed areas will be seeded upon completing of finish grading. Refer to the landscape plans for detailed planting and seeding schedule. 6. Mulching. Spread straw mulch uniformly over seeded areas at a rate of 90 lbs per 1000 square feet of ground. No more than 25% of the ground should be visible. Crimp or pinch mulch into soil 2-4 inches by using either a mulch anchoring tool, a farm disk operating on the contour of the slope, or by cleating with bulldozer tracks operating up and down the slopes (to prevent tracks from forming gullies). 7. Required maintenance activities (e.g. after-storm checks of all BMPs, etc.). All temporary sediment control BMPs shall be inspected after each rain event to ensure proper protection and to determine if cleaning is necessary. Final cleaning of all storm facilities shall be provided upon final stabilization of site. CSU Health and Medical Center - Erosion Control Report Page 9 of 10 SECTION 4 – CONCLUSIONS The goal of the erosion control report is to describe appropriate controls and measures to improve water quality by reducing pollutants in stormwater discharges and ensure compliance with the requirements of the City of Fort Collins Erosion Control Standards. The proposed improvements for the Medical Center will increase the overall imperviousness of the site over the existing condition. However, total storm water runoff discharging into Mason Street Outfall will be decreased from the historic flow rates. Both the existing and proposed permanent structural BMP’s on site, including the detention pond, capture the majority of the runoff discharged from the site and will improve storm water quality by facilitating sedimentation and filtering of runoff. Temporary BMP’s to be employed during the construction of the proposed improvements include straw wattles and rock socks at the downstream limits of disturbance, slope protection on the vegetated swale if necessary, a concrete washout facility on site, street sweeping practices to eliminate tracked sediment, and vehicle tracking control. These measures, along with the other standard Best Management Practices described in this report, will serve to reduce pollutants in the storm water runoff and satisfy the requirements of the City of Fort Collins Erosion Control Standards. CSU Health and Medical Center - Erosion Control Report Page 10 of 10 SECTION 5 – REFERENCES 1. Urban Storm Drainage Criteria Manual (Volumes 1, 2, and 3), Urban Drainage and Flood Control District, June 2001, Revised April 2008. 2. Storm Drainage Criteria Manual and Construction Standards, City of Fort Collins Storm Water Utility, City of Fort Collins, Colorado, Updated January, 1997 with 2012 amendments. 3. “Geotechnical Investigation Propose Medical Center”, CTL Thompson, Incorporated. Dated August 18, 2015 APPENDIX A – UTILITY PLANS 1. Erosion Control Plan (CE1.0) 2. SWMP and Erosion Control Details (CE1.1-1.2) 3. Overall Grading Plan (C1.0) 4. Detailed Grading Plans (C1.1-1.6) LAKE STREET SOUTH COLLEGE AVENUE MASON CORRIDOR TRANSITWAY WEST PROSPECT ROAD CE1.0 EROSION CONTROL PLAN Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 CE1.1 SWMP & EROSION CONTROL DETAILS Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 CE1.2 EROSION CONTROL DETAILS Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 LAKE STREET SOUTH COLLEGE AVENUE MASON CORRIDOR TRANSITWAY WEST PROSPECT ROAD C1.0 OVERALL GRADING PLAN Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 MASON CORRIDOR TRANSITWAY LAKE STREET Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 LAKE STREET SOUTH COLLEGE AVENUE Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 MASON CORRIDOR TRANSITWAY Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 303 . 623 . 2836 Fax Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION WEST PROSPECT ROAD MASON CORRIDOR TRANSITWA Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 SOUTH COLLEGE AVENUE WEST PROSPECT ROAD Date Drawn By Checked By Project Number Sheet of Issue Revisions OWNER'S REPRESENTATIVE Colorado State University Facilities Management 251 Edison Drive Fort Collins, CO, 80523-6030 970.491.0080 - Phone 970.491.7572 - Fax CIVIL ENGINEER JVA Consulting Engineers 25 Old Town Square, Ste. 200 Fort Collins, CO 80524 303.444.1951 LANDSCAPE ARCHITECT Design Workshop 1390 Lawrence St. Ste. 100 Denver, CO, 80204 303.623.2616 STRUCTURAL ENGINEER JVA Consulting Engineers 1319 Spruce St. Boulder, CO, 80302 303.444.1951 MECHANICAL / ELECTRICAL / PLUMBING ENGINEERING ME Engineers 14143 Denver West Parkway, Ste. 300 Golden, CO, 80401 303.421.6655 ELECTRICAL Gregory Electric 3317 North Lincoln Ave Loveland, CO, 80538 970-669-7609 MECHANICAL CONTRACTOR US Engineering Co 1100 W. 120th Ave #900 Westminster, CO, 80234 303.964.8060 ENERGY / ENVIRONMENTAL Ambient Energy 130 W. 5th Ave Denver, CO, 80204 303.278.1532 SPECIFICATIONS Specifications for Architects, Inc. 6560 West Alamo Drive Littleton, CO, 80123 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 APPENDIX B – EROSION CONTROL ESCROW 11/11/2015 Project: Disturbed Acres: 5.70 EROSION CONTROL BMPs Units Estimated Quantity Unit Price Total Price each 2 $750.00 $1,500.00 each 6 $150.00 $900.00 L.F. 2000 $2.00 $4,000.00 each 1 $1,200.00 $1,200.00 each 15 $400.00 $6,000.00 each 2 $1,000.00 $2,000.00 LS 1 $2,000.00 $2,000.00 Sub-Total: $17,600.00 1.5 x Sub-Total: $26,400.00 Amount of security: $26,400.00 AC 0.75 $2,000.00 $1,500.00 Sub-Total: $1,500.00 1.5 x Sub-Total: $2,250.00 Amount to Re-seed: $2,250.00 Minimum escrow amount: $3,000.00 Erosion Control Escrow: $26,400.00 Erosion and Sediment Control Escrow/Security Calculation for The City of Fort Collins BMP Amount Vehicle Tracking Control Pad Concrete Washout Street Sweeping and Cleaning Reseeding Amount Sediment Control Log Miniumum Escrow Amount Colorado State University Health and Medical Center Seeding “The amount of the security must be based on one and one-half times the estimate of the cost to install the approved measures, or one and one-half times the cost to re-vegetate the disturbed land to dry land grasses based upon unit cost determined by the City's Annual Revegetation and Stabilization Bid, whichever is greater. In no instance, will the amount of security be less than one thousand five hundred dollars ($1,500) for residential development or three thousand dollars ($3,000) for commercial development” Rock Sock Final Escrow Amount (Maximum between BMP, Reseeding and Minimum Escrow) Inlet Protection Outlet Protection 11/11/2015 12:07 PM V:\2487c CSU Medical Building\Reports\Erosion Control Report\GoSC Erosion Control Escrow.xls APPENDIX C – SOIL DATA FROM CTL THOMPSON 400 North Link Lane | Fort Collins, Colorado 80524 Telephone: 970-206-9455 Fax: 970-206-9441 GEOTECHNICAL INVESTIGATION PROPOSED MEDICAL CENTER COLORADO STATE UNIVERSITY FORT COLLINS, COLORADO COLORADO STATE UNIVERSITY 251 Edison, 6030 Campus Delivery Fort Collins, Colorado 80526-6030 Attention: Mr. Milt Brown Project Manager Project No. FC07034-125 August 18, 2015 COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS AND PROPOSED CONSTRUCTION 2 INVESTIGATION 3 SUBSURFACE CONDITIONS 3 SITE DEVELOPMENT 4 Fill Placement 4 Excavations 6 FOUNDATIONS 6 Spread Footings with Minimum Deadload 6 Drilled Piers Bottomed in Bedrock 7 Laterally Loaded Piers 8 Closely Spaced Pier Reduction Factors 9 BELOW GRADE AREAS 10 FLOOR SYSTEMS 10 PAVEMENTS 13 Pavement Selection 14 Subgrade and Pavement Materials and Construction 14 Pavement Maintenance 14 WATER-SOLUBLE SULFATES 15 SURFACE DRAINAGE 16 FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS FIGURES 2 THROUGH 4 – SUMMARY LOGS OF EXPLORATORY BORINGS APPENDIX A – RESULTS OF LABORATORY TESTING APPENDIX B – SAMPLE SITE GRADING SPECIFICATIONS APPENDIX C – PAVEMENT CONSTRUCTION RECOMMENDATIONS APPENDIX D – PAVEMENT MAINTENANCE PROGRAM COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 1 SCOPE This report presents the results of our Geotechnical Investigation for the proposed Colorado State University Medical Center in Fort Collins, Colorado. The purpose of the investigation was to evaluate the subsurface conditions and provide foundation recommendations and geotechnical design criteria for the pro- ject. The scope was described in our Service Agreement (FC-15-0245, dated July 8, 2015). The report was prepared from data developed during field exploration, la- boratory testing, engineering analysis and experience with similar conditions. The report includes a description of subsurface conditions found in our explora- tory borings and discussions of site development as influenced by geotechnical considerations. Our opinions and recommendations regarding design criteria and construction details for site development, foundations, floor systems, slabs- on-grade, pavements and drainage are provided. If the proposed construction changes, we should be requested to review our recommendations. Our conclu- sions are summarized in the following paragraphs. SUMMARY OF CONCLUSIONS 1. In general, soils encountered in our borings consisted of sandy clay. A layer of gravelly sand was encountered in three of our bor- ings below and/or within the clay layer. Sandstone bedrock was encountered in eight of our borings at depths of 18 to 24 feet to the depths explored. 2. Groundwater was encountered in eight borings at depths of 12 to 19 feet during drilling and 11 to 16½ feet when measured several days later. Existing groundwater levels are not expected to signifi- cantly affect the proposed construction, but may affect drilled pier installation. 3. Existing fill was encountered in our borings. Several structures were still located on the site that will be demolished prior to con- COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 2 struction. All structures should be completely removed below im- provements. The existing fill should be completely removed and re- compacted below the proposed building. 4. We believe the proposed structure can be constructed on spread footing foundations with a minimum dead load placed on natural, undisturbed soil and/or properly compacted fill or a drilled pier foun- dation bottomed into bedrock. Foundation design and construction recommendations are presented in this report. 5. The presence of expansive soils and bedrock constitutes a geologic hazard. There is risk that slabs-on-grade and foundations will heave or settle and be damaged. We believe the recommendations presented in this report will help to control risk of damage; they will not eliminate that risk. Slabs-on-grade and, in some instances, foundations may be damaged. 6. We believe a slab-on-grade floor is appropriate for this site. Some movement of slab-on-grade floors should be anticipated. We ex- pect movements will be minor, on the order of 1 inch or less. If movement cannot be tolerated, structural floors should be consid- ered. 7. Pavement areas including parking and access drives are planned for this project. Four borings were drilled in the area of the pro- posed pavements. Pavement section recommendations are in- cluded in this report. SITE CONDITIONS AND PROPOSED CONSTRUCTION The site is located northwest of Prospect Road and College Avenue in Fort Collins, Colorado (Figure 1). Several vacant residences are located at the site that are to be demolished. We understand the proposed construction will in- clude a new Medical Center. The 4-story Medical Center will be approximately 120,000 square feet. Associated pavement areas will included parking and ac- cess drives. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 3 INVESTIGATION Subsurface conditions were investigated by drilling twelve borings to depths of approximately 10 to 35 feet. The approximate locations of the borings are shown on Figure 1. Our field representative observed drilling, logged the soils and bedrock found in the borings and obtained samples. Sampling was performed by driving a 2.5-inch O.D. modified California sampler with blows of a 140-pound hammer falling 30 inches. This method is similar to the standard pen- etration test, and is typical for local practice. Groundwater measurements were taken during drilling and one, or more, days after drilling. Summary logs of the borings, including results of field penetration resistance tests, are presented on Figures 2 through 4. Samples obtained during drilling were returned to our laboratory and visu- ally examined by the geotechnical engineer for this project. Laboratory analyses included moisture content, dry density, swell-consolidation, Atterberg limits, parti- cle-size analysis and water-soluble sulfate tests. Results of laboratory tests are presented in Appendix A and summarized in Table A-I. SUBSURFACE CONDITIONS In general, soils encountered in our borings consisted of sandy clay. The upper 2½ to 15 feet of clay was considered man-placed fill. A layer of gravelly sand was encountered in three of our borings below and/or within the clay layer. Sandstone bedrock was encountered in eight of our borings at depths of 18 to 24 feet to the depths explored. Groundwater was encountered in eight borings at depths of 12 to 19 feet during drilling and 11 to 16½ feet when measured several days later. Groundwa- ter levels are expected to fluctuate seasonally. Existing groundwater levels are not expected to significantly affect the proposed construction, but may affect drilled pier installation. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 4 SEISMICITY This area, like most of central Colorado, is subject to a low degree of seis- mic risk. As in most areas of recognized low seismicity, the record of the past earthquake activity in Colorado is incomplete. According to the 2012 International Building Code and the subsurface con- ditions encountered in our borings, this site probably classifies as a Site Class C. Only minor damage to relatively new, properly designed and built buildings would be expected. Wind loads, not seismic considerations, typically govern dynamic structural design in this area. SITE DEVELOPMENT Fill Placement The existing onsite soils are suitable for re-use as fill material provided de- bris or deleterious organic materials are removed. If import material is used, it should be tested and approved as acceptable fill by CTL|Thompson. In general, import fill should meet or exceed the engineering qualities of the onsite soils. Ar- eas to receive fill should be scarified, moisture-conditioned and compacted to at least 95 percent of standard Proctor maximum dry density (ASTM D698, AASHTO T99). Sand soils used as fill should be moistened to within 2 percent of optimum moisture content. Clay soils should be moistened between optimum and 3 percent above optimum moisture content. The fill should be moisture-con- ditioned, placed in thin, loose lifts (8 inches or less) and compacted as described above. We should observe placement and compaction of fill during construction. Fill placement and compaction should not be conducted when the fill material is frozen. The upper 2½ to 15 feet of material encountered in seven of our borings was considered existing fill. The fill was likely placed during construction of the COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 5 existing residences and infrastructure. Deeper fill areas may be encountered during site development. The fill is of unknown origin and age. The fill presents a risk of settlement or heave to improvements constructed on the fill. We recom- mend the fill be removed and recompacted in the building area. The fill removal area should extend beyond the building footprint at least 5 feet. The excavation can be filled with on-site soils, moisture-conditioned and compacted as described above. This procedure should remove the existing fill and provide more uniform support for improvements. The existing fill can also affect pavements and exterior flatwork. The low- est risk alternative for exterior pavement and flatwork would also be complete re- moval and recompaction. The cost could be significant. If the owner can accept a risk of some movement and distress in these areas then partial depth removal is an alternative. We suggest removal of the existing fill to a depth of 2 feet be- low existing grade, proof rolling the exposed subgrade, and additional removal or stabilization of areas where soft, yielding or organic soils or debris is encoun- tered. After this, fill placement can proceed to construction grades. Site grading in areas of landscaping where no future improvements are planned can be placed at a dry density of at least 90 percent of standard Proctor maximum dry density (ASTM D 698, AASHTO T 99). Example site grading spec- ifications are presented in Appendix B. Water and sewer lines are often constructed beneath areas where im- provements are planned. Compaction of trench backfill can have a significant ef- fect on the life and serviceability overlying structures. We recommend trench backfill be moisture conditioned and compacted as described in the Fill Place- ment section of this report. Placement and compaction of fill and backfill should be observed and tested by a representative of our firm during construction. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 6 Excavations The materials found in our borings can be excavated using conventional heavy-duty excavation equipment. Excavations should be sloped or shored to meet local, State and Federal safety regulations. Excavation slopes specified by OSHA are dependent upon types of soil and groundwater conditions encoun- tered. The contractor’s “competent person” should identify the soils and/or rock encountered in the excavation and refer to OSHA standards to determine appro- priate slopes. FOUNDATIONS Our investigation indicates low to moderate swelling soils are present at the anticipated foundation levels. Spread footing foundations are considered ap- propriate for the conditions encountered. A drilled pier foundation can also be considered to minimize movements and for higher loads. Design criteria for spread footing and drilled pier foundations developed from analysis of field and laboratory data and our experience are presented below. Spread Footings with Minimum Deadload 1. Footings should be constructed on undisturbed natural soils or properly compacted fill (see the Fill Placement section of this re- port). Where soil is loosened during excavation, it should be re- moved and replaced with on-site soils compacted following the cri- teria in the Fill Placement section of this report. 2. Footings constructed on the natural soils and/or engineered fill can be designed for a net allowable soil pressure of 3,000 psf and a minimum dead load pressure of 1,000 psf. The soil pressure can be increased 33 percent for transient loads such as wind or seismic loads. 3. Footings should have a minimum width of at least 16 inches. Foun- dations for isolated columns should have minimum dimensions of 18 inches by 18 inches. Larger sizes may be required depending on loads and the structural system used. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 7 4. The soils beneath footing pads can be assigned an ultimate coeffi- cient of friction of 0.45 to resist lateral loads. The ability of grade beam or footing backfill to resist lateral loads can be calculated us- ing a passive equivalent fluid pressure of 300 pcf. This assumes the backfill is densely compacted and will not be removed. Backfill should be placed and compacted to the criteria in the Fill Place- ment section of this report. 5. To meet the minimum deadload criteria, a continuous void with min- imum 4-inch thickness should be placed below grade beams, be- tween pads to concentrate the load of the structures on the footing pads. 6. Exterior footings should be protected from frost action. We believe 30 inches of frost cover is appropriate for this site. 7. Foundation walls and grade beams should be well reinforced both top and bottom. We recommend the amount of steel equivalent to that required for a simply supported span of 10 feet. 8. We should observe completed footing excavations to confirm that the subsurface conditions are similar to those found in our borings. Drilled Piers Bottomed in Bedrock 1. Piers should be designed for a maximum allowable end pressure of 30,000 psf and an allowable skin friction of 3,000 psf for the portion of pier in bedrock. Skin friction should be neglected for the upper 3 feet of pier below grade beams. Pier end pressure can be in- creased 30 percent for short duration live loads such as wind loads. 2. Piers should penetrate at least 6 feet into the comparatively fresh sandstone bedrock. 3. Drilled piers should be designed to resist an ultimate uplift force cal- culated as (30 kips x pier diameter in feet) to resist tension in the event of swelling. Reinforcement should extend into grade beams and foundation walls. 4. There should be a 4-inch (or thicker) continuous void beneath all grade beams and foundation walls, between piers, to concentrate the dead load of the structure onto the piers. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 8 5. Foundation walls and grade beams should be well reinforced. A qualified structural engineer should design the reinforcement. Lat- eral earth pressures and the effects of large openings within base- ment walls should be considered. 6. Pier borings should be drilled to a plumb tolerance of 1.5 percent relative to the pier length. 7. Piers should be carefully cleaned prior to placement of concrete. Groundwater was encountered during this investigation. Concrete should not be placed by free fall if there is more than 3 inches of water at the bottom of the hole. If more than 3 inches of ground wa- ter collects in the bottom of the holes during pier installation, tempo- rary casing, tremie equipment, and/or pumping may be necessary for proper cleaning, dewatering, and concrete placement. 8. Concrete placed by the free fall method should have a slump be- tween 5 inches and 7 inches. Concrete placed by pump, tremie or when temporarily cased should have a slump between 6 inches and 8 inches. 9. Formation of “mushrooms” or enlargements at the top of piers should be avoided during pier drilling and subsequent construction operations. 10. We should observe installation of drilled piers to confirm the sub- surface conditions are those we anticipated from our borings. Laterally Loaded Piers Several methods are available to analyze laterally loaded piers. With a pier length to diameter ratio of 7 or greater, we believe the method of analysis developed by Matlock and Reese is most appropriate. The method is an iterative procedure using applied loading and soil profile to develop deflection and mo- ment versus depth curves. The computer programs LPILE and COM624 were developed to perform this procedure. Suggested criteria for LPILE analysis are presented in the following table. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 9 TABLE A SOIL INPUT DATA FOR LPILE or COM624 Clay Soils or Clay Fill Granular Soils Sandstone Soil Type Stiff Clay w/o Free Water Sand Sand Effective Unit Weight (pci) 0.07 0.035 0.07 Cohesive Strength, c (psi) 14 - - Friction Angle Degrees - 35 45 Soil Strain, ε50 (in/in) 0.005 - - p-y Modulus ks (pci) 1,000 60 225 The ε50 represents the strain corresponding to 50 percent of the maximum princi- ple stress difference. Closely Spaced Pier Reduction Factors For axial loading, a minimum spacing of three diameters is recommended. At one diameter (piers touching) the skin friction reduction factor for both piers would be 0.5. End bearing values would not be reduced provided the bases of the piers are at similar elevations. Linear interpolation can be used between one and three diameters. Piers in-line with the direction of the lateral load should have a minimum spacing of six diameters (center-to-center) based upon the larger pier. If a closer spacing is required, the modulus of subgrade reaction for initial and trailing piers should be reduced. At a spacing of three diameters, the effective modulus of subgrade reaction of the first pier can be estimated by multiplying the given mod- ulus by 0.6. For trailing piers in a line at three-diameter spacing, the factor is 0.4. Linear interpolation can be used for spacing between three and six diameters. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 10 Reductions to the modulus of subgrade reaction can be accomplished in LPILE by inputting the appropriate modification factors for the p-y curves. Re- ducing the modulus of subgrade reaction in trailing piers will result in greater computed deflections on these piers. In practice, the grade beam can force de- flections of piers to be equal. Load-deflection graphs can be generated for each pier in the group using the appropriate p-multiplier values. The sum of the piers’ lateral load resistance at selected deflections can be used to develop a total lat- eral load versus deflection relationship for the system of piers. For lateral loads perpendicular to the line of piers a minimum spacing of three diameters can be used with no capacity reduction. At one diameter (piers touching) the piers can be analyzed as a single unit. Linear interpolation can be used for intermediate conditions. BELOW GRADE AREAS No basement areas are planned for the buildings. For this condition, pe- rimeter drains are not usually necessary. We should be contacted to provide foundation drain recommendations if plans change to include basement areas. FLOOR SYSTEMS In our opinion, it is reasonable to use slab-on-grade floors for the pro- posed construction. Any fill placed for the floor subgrade should be built with densely compacted, engineered fill as discussed in the Fill Placement section of this report. The existing fill is not an acceptable subgrade for a slab-on-grade floor and should be completely removed from the subgrade under a floor. It is impossible to construct slab-on-grade floors with no risk of movement. We believe movements due to swell will be less than 1 inch at this site. If move- ment cannot be tolerated, structural floors should be used. Structural floors can COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 11 be considered for specific areas that are particularly sensitive to movement or where equipment on the floor is sensitive to movement. Where structurally supported floors are selected, we recommend a mini- mum void between the ground surface and the underside of the floor system of 4 inches. The minimum void should be constructed below beams and utilities that penetrate the floor. The floor may be cast over void form. Void form should be chosen to break down quickly after the slab is placed. We recommend against the use of wax or plastic-coated void boxes. Slabs may be subject to heavy point loads. The structural engineer should design floor slab reinforcement. For design of slabs-on-grade, we recom- mend a modulus of subgrade reaction of 90 pci for on-site soils. If the owner elects to use slab-on-grade construction and accepts the risk of movement and associated damage, we recommend the following precautions for slab-on-grade construction at this site. These precautions can help reduce, but not eliminate, damage or distress due to slab movement. 1. Slabs should be separated from exterior walls and interior bearing members with a slip joint that allows free vertical movement of the slabs. This can reduce cracking if some movement of the slab oc- curs. 2. Slabs should be placed directly on exposed soils or properly mois- ture conditioned, compacted fill. The 2012 International Building Code (IBC) requires a vapor retarder be placed between the base course or subgrade soils and the concrete slab-on-grade floor. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building use to moisture. A properly installed vapor retarder (10 mil minimum) is more benefi- cial below concrete slab-on-grade floors where floor coverings, painted floor surfaces or products stored on the floor will be sensi- tive to moisture. The vapor retarder is most effective when con- crete is placed directly on top of it, rather than placing a sand or gravel leveling course between the vapor retarder and the floor COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 12 slab. The placement of concrete on the vapor retarder may in- crease the risk of shrinkage cracking and curling. Use of concrete with reduced shrinkage characteristics including minimized water content, maximized coarse aggregate content, and reasonably low slump will reduce the risk of shrinkage cracking and curling. Con- siderations and recommendations for the installation of vapor re- tarders below concrete slabs are outlined in Section 3.2.3 of the 2006 report of American Concrete Institute (ACI) Committee 302, “Guide for Concrete Floor and Slab Construction (ACI 302.R1-04)”. 3. If slab-bearing partitions are used, they should be designed and constructed to allow for slab movement. At least a 2-inch void should be maintained below or above the partitions. If the “float” is provided at the top of partitions, the connection between interior, slab-supported partitions and exterior, foundation supported walls should be detailed to allow differential movement. 4. Underslab plumbing should be eliminated where feasible. Where such plumbing is unavoidable it should be thoroughly pressure tested for leaks prior to slab construction and be provided with flexi- ble couplings. Pressurized water supply lines should be brought above the floors as quickly as possible. 5. Plumbing and utilities that pass through the slabs should be iso- lated from the slabs and constructed with flexible couplings. Where water and gas lines are connected to furnaces or heaters, the lines should be constructed with sufficient flexibility to allow for move- ment. 6. HVAC equipment supported on the slab should be provided with a collapsible connection between the furnace and the ductwork, with allowance for at least 2 inches of vertical movement. 7. The American Concrete Institute (ACI) recommends frequent con- trol joints be provided in slabs to reduce problems associated with shrinkage cracking and curling. To reduce curling, the concrete mix should have a high aggregate content and a low slump. If desired, a shrinkage compensating admixture could be added to the con- crete to reduce the risk of shrinkage cracking. We can perform a mix design or assist the design team in selecting a pre-existing mix. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 13 PAVEMENTS The project will include paved parking areas and access drives. The per- formance of a pavement structure is dependent upon the characteristics of the subgrade soil, traffic loading and frequency, climatic conditions, drainage and pavement materials. As part of our investigation for this project, we drilled three exploratory borings and conducted laboratory tests for characterization of the subgrade soils in the area of the proposed pavements. Laboratory tests indi- cated the subgrade soils generally classified as A-6 and A-7 soils with predicted fair to poor subgrade support. If fill is needed, we have assumed it will be soils with similar or better characteristics. We understand flexible hot mix asphalt (HMA) pavement is planned for the parking lot. Rigid portland cement concrete (PCC) pavement should be consid- ered for trash enclosure areas and where the pavement will be subjected to fre- quent turning of heavy vehicles. Alternatives that include each material are pro- vided below. Our designs are based on the AASHTO design method and our ex- perience. Using the criteria discussed above we recommend the minimum pave- ment sections provided in Table B. TABLE B RECOMMENDED PAVEMENT SECTIONS Classification Hot Mix Asphalt (HMA) + Aggre- gate Base Course (ABC) Portland Cement Concrete (PCC) Parking Area 4" HMA + 6" ABC 6" PCC Access Drives 5" HMA + 6" ABC 6" PCC Trash Enclosures - 6" PCC COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 14 Pavement Selection Composite HMA/ABC pavement over a stable subgrade is expected to perform well at this site based on the recommendations provided. HMA provides a stiff, stable pavement to withstand heavy loading and will provide a good fa- tigue resistant pavement. However, HMA does not perform well where point loads are subjected and in areas where heavy trucks turn and maneuver at slow speeds. PCC pavement is also expected to perform well in this area. PCC pavement has better performance in freeze-thaw conditions and should require less long-term maintenance than HMA pavement. In any event, the performance of the pavement structure depends partly on the stability of the subgrade soils. Subgrade and Pavement Materials and Construction The design of a pavement system is as much a function of the quality of the paving materials and construction as the support characteristics of the sub- grade. The construction materials are assumed to possess sufficient quality as reflected by the strength factors used in our design calculations. Moisture treat- ment criteria and additional criteria for materials and construction requirements are presented in Appendix C of this report. Pavement Maintenance Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the long-term life of a pavement system. We recommend a preven- tive maintenance program be developed and followed for all pavement systems to assure the design life can be realized. Choosing to defer maintenance usually results in accelerated deterioration leading to higher future maintenance costs, and/or repair. A recommended maintenance program is outlined in Appendix D. COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 15 Excavation of completed pavement for utility construction or repair can de- stroy the integrity of the pavement and result in a severe decrease in serviceabil- ity. To restore the pavement top original serviceability, careful backfill compac- tion before repaving is necessary. WATER-SOLUBLE SULFATES Concrete that comes into contact with soils can be subject to sulfate at- tack. We measured water-soluble sulfate concentrations in seven samples from this site. Concentrations measured were between 0.06 and 1.2 percent, with two samples having sulfate concentrations greater than 0.2 percent. Water-soluble sulfate concentrations between 0.2 and 2 percent indicate Class 2 sulfate expo- sure, according to the American Concrete Institute (ACI). For sites with Class 2 sulfate exposure, ACI recommends using a cement meeting the requirements for Type V (sulfate resistant) cement or the equivalent, with a maximum water-to-ce- mentitious material ratio of 0.45 and air entrainment of 5 to 7 percent. As an al- ternative, ACI allows the use of cement that conforms to ASTM C 150 Type II re- quirements, if it meets the Type V performance requirements (ASTM C 1012) of ACI 201, or ACI allows a blend of any type of portland cement and fly ash that meets the performance requirements (ASTM C 1012) of ACI 201. In Colorado, Type II cement with 20 percent Class F fly ash usually meets these performance requirements. The fly ash content can be reduced to 15 percent for placement in cold weather months, provided a water-to-cementitious material ratio of 0.45 or less is maintained. ACI also indicates concrete with Class 2 sulfate exposure should have a minimum compressive strength of 4,500 psi. Sulfate attack problems are comparatively rare in this area when quality concrete is used. Considering the range of test results, we believe risk of sulfate attack is lower than indicated by the few laboratory tests performed. The risk is also lowered to some extent by damp-proofing the surfaces of concrete walls in contact with the soil. ACI indicates sulfate resistance for Class 1 exposure can COLORADO STATE UNIVERSITY CSU MEDICAL CENTER CTLT PROJECT NO. FC07034-125 16 be achieved by using Type II cement, a maximum water-to-cementitious material ratio of 0.50, and a minimum compressive strength of 4000 psi. We believe this approach should be used as a minimum at this project. The more stringent measures outlined in the previous paragraph will better control risk of sulfate at- tack and are more in alignment with written industry standards. SURFACE DRAINAGE Performance of foundations, flatwork and pavements are influenced by changes in subgrade moisture conditions. Carefully planned and maintained sur- face grading can reduce the risk of wetting of the foundation soils and pavement subgrade. Positive drainage should be provided away from foundations. Backfill around foundations should be moisture treated and compacted as described in Fill Placement. Roof drains should be directed away from buildings. Downspout extensions and splash blocks should be provided at discharge points. LIMITATIONS Although our borings were spaced to obtain a reasonably accurate picture of subsurface conditions, variations not indicated in our borings are possible. We should observe footing excavations to confirm soils are similar to those found in our borings or pier hole drilling to confirm adequate penetration into bedrock. Placement and compaction of fill, backfill, subgrade and other fills should be ob- served and tested by a representative of our firm during construction. This report was prepared from data developed during our field exploration, laboratory testing, engineering analysis and experience with similar conditions. The recommendations contained in this report were based upon our understand- ing of the planned construction. If plans change or differ from the assumptions presented herein, we should be contacted to review our recommendations. 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.6 DETAILED GRADING PLAN - SOUTHEAST CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.5 DETAILED GRADING PLAN - SOUTHWEST CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.4 DETAILED GRADING PLAN - EAST CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.3 DETAILED GRADING PLAN - WEST CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.2 DETAILED GRADING PLAN - NORTHEAST CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER C1.1 DETAILED GRADING PLAN - NORTHWEST CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner 303.927.8362 1301 Wazee . Suite 100 Denver . Colorado . 80204 303 . 623 . 7323 303 . 623 . 2836 Fax NOT FOR CONSTRUCTION 797 Ventura St. Aurora. Colorado. 80011 303 . 363 . 7101 303 . 363 . 9251 Fax Owner Project Number BENNETT WAGNER GRODY ARCHITECTS 10/8/2015 12:22:27 PM OCTOBER 30, 2015 14-023 151 W. Lake Street Fort Collins, CO 80524 DD Core / Shell Progress KRB KAT 15042.00 CSU HEALTH AND MEDICAL CENTER CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: CHECKED BY: Date Date Date Date Date Date City of Fort Collins, Colorado UTILITY PLAN APPROVAL Parks and Recreation Traffic Engineer Stormwater Utility Water & Wastewater Utility City Engineer CHECKED BY: APPROVED: Date Environmental Planner