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HomeMy WebLinkAboutPVH MEDICAL OFFICE BUILDING & PARKING STRUCTURE - PDP - 14-07 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGeotechnical Engineering Report Teffam McWhinney — Poudre Valley Hospital MOB SNV/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Seismic Considerations The project site is located in Seismic Risk Zone I of the Seismic Zone Map of the United States as indicated by the 1997 Uniform Building Code. Based upon the nature of the subsurface materials, Soil Profile Type "Sc" should be used for the design of structures for the proposed project (1997 Uniform Building Code, Table No. 16-J). A site classification "C" should be used for the design of structures for the proposed project (2003 International Building Code, Table No. 1615.1.1). Floor Slab Design and Construction Some differential movement of a slab -on -grade floor system is possible should the subgrade soils become elevated in moisture content. To reduce potential slab movements, the subgrade soils should be prepared as outlined in the earthwork section of this report. For structural design of concrete slabs -on -grade, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) may be used for floors supported on existing soils. A modulus of 200 pci may be used for floors supported on non -expansive imported structural fill material approved by the geotechnical engineer. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. However, even if these procedures are followed, some movement and at least minor cracking in the structure's foundation system and floor slab should be anticipated. The severity of cracking and other cosmetic damage such as uneven floor slabs will probably increase if any modification of the site results in excessive wetting or drying of the expansive materials. Eliminating the risk of movement and cosmetic distress may not be feasible, but it may be possible to further reduce the risk of movement if significantly more expensive measures are used during construction. Some of these options, such as the use of structural floors or overexcavating and replacing expansive materials are discussed in this report. We would be pleased to discuss other construction alternatives with you upon request. Additional floor slab design and construction recommendations for floor slabs are as follow: • Remove all existing fill material where encountered, from below proposed slabs and replaced with approved engineered fill material. • Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. • Control joints should be provided in slabs to control the location and extent of cracking. 10 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIWIC of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lrerracon 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. 23 i Geotechnical Engineering Report McWhinney— Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Curing TErncan 1. The final layer of treated subgrade should be thoroughly rolled with a pneumatic tire roller, skimmed with a road grader to a depth of approximately 1/4-inch removing all loosened stabilized material from the section. The moisture content of the surface material must be maintained within the specified range during all finishing. Finishing shall proceed in such a manner as to produce, in not more than 2 hours, a smooth, closely knit surface free of cracks, ridges or loose material conforming to grades and plans. 2. After the fly ash treated course has been finished as specified, the surface shall be protected against rapid drying by either of the following curing methods for a period of not less than 3 days or until the surface of subsequent courses are in place. (a) By maintaining a continuous moisture condition by sprinkling; or (b) By applying an asphalt membrane to the treated course immediately after it is completed. The type of asphalt used shall be sufficient to completely cover and seal the total surface. 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. 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 or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, 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 22 Geotechnical Engineering Report lrerracm 1 McWhinney— Poudre Valley Hospital MOB SIWIC of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 6. The fly ash shall be spread by a method approved by the engineer at the rate shown on the plan or as directed by the engineer. Fly ash shall not be applied when wind conditions in the opinion of the engineer are such that blowing fly ash becomes objectionable to traffic or adjacent property owners. 7. During the final mixing, the material shall be sprinkled as directed by the engineer until the proper moisture content has been obtained. However, initial mixing after the addition to fly ash may be accomplished dry or with a minimum of water to prevent fly ash balls. 8. Final moisture content of the mix prior to compaction shall not exceed the optimum moisture content by more than 2 percent nor be less than the optimum moisture by more than 2 percent during placement and compaction procedures. 9. The soil and fly ash shall be thoroughly mixed with approved road mixers or other approved equipment and the mixing continued until in the opinion of the engineer a homogeneous and friable mixture of soil and fly ash is obtained free from clods or lumps. Water required to achieve the specific moisture content for the mixture should be added after initial mixing. Compaction of the mixture shall begin immediately after mixing of the . fly ash and shall be completed within 2 hours following addition of water to the fly ash. The material shall be sprinkled as necessary to maintain the optimum moisture. Compaction of Fly Ash and Soil Mixture 1. Place and compact subgrade in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift as described above. 2. Compaction of the mixture shall begin at the bottom and continue until the entire depth of the mixture is uniformly and compacted to the specified density. 3. Uncompacted fill lifts should not exceed 12 inches loose thickness. 4. No fill should be placed over frozen ground. 5. The fly ash materials should be compacted to a minimum of 95% of Standard Proctor Density ASTM D698. 21 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SMIC of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lferracan water in areas adjacent to the building or pavements, should be sealed or eliminated. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately 5 percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. Sprinkler systems should not be installed within 10-feet of foundation walls. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. General Considerations for Fly ash Subgrade Preparation The conclusions contained in this report for the proposed construction are contingent upon compliance with recommendations presented in this section as well as those presented in LCUASS Pavement Design Manual — Chapter 22. The following provides general fly ash 1 construction guidelines, which should be followed in conjunction with those presented in Chapter 22 of the LCUASS manual. Fly Ash Placement The upper 12 inches of existing subgrade should be treated with a minimum of 12 percent of Class C fly ash. The fly ash shall consist of Class C fly ash meeting ASTM Specification C 618. 2. Water used in the stabilized mixture should be potable. 3. The machinery, equipment and tools necessary for proper placement of the fly ash and soil mixture should be suitable for properly mixing and compacting the soil and fly ash mixture. 4. It is important to secure a completed course of treated material, which contains a uniform fly ash soil mixture with no loose or segregated areas. The material should have a uniform density and moisture content, is well bound its full depth and has a smooth surface suitable for placing base course and pavement. 5. The subgrade should be graded and shaped to enable the fly ash treatment of materials in place in conformance with lines, grades and thickness shown on the plans. 20 Geotechnical Engineering Report McWhinney— Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 providing structural exterior slabs supported on foundations similar to the building. Corrosion Protection lrerracan Results of soluble sulfate testing indicate that ASTM Type I Portland cement is suitable for all concrete on and below grade. However, if there is no, or minimal cost differential, use of ASTM Type II Portland cement is recommended for additional sulfate resistance of construction concrete. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Laboratory test results indicate that on -site soils have resistivities ranging from approximately 2,270 to 2,940 ohm -centimeters, pH values ranging from 7.1 to 7.3, oxidation-reduction (Redox) potential ranging from 110 to 140 milli -volts, (mV), along with trace amounts of sulfide contents, or below the laboratory detection limits of 0.1 mg/kg. These values should be used to determine potential corrosive characteristics of the on -site soils with respect to contact with the various underground materials, which will be used during the projects construction phases. Underground Utility Systems All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should consist of the on -site soils or imported material approved by the geotechnical engineer. The pipe backfill should be compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698. Temporary dewatering measures may be required if utility excavations are required to be extended to or near existing groundwater levels. Surface Drainage All grades must provide effective drainage away from the building during and after construction. Water permitted to pond next to the building can result in greater soil movements than those discussed in this report. These greater movements can result in unacceptable differential floor slab movements, cracked slabs and walls, and roof leaks. Estimated movements described in this report are based on effective drainage for the life of the structure and cannot be relied upon if effective drainage is not maintained. Positive drainage should be provided during construction and maintained throughout the life of the proposed project. Infiltration of water into utility or foundation excavations must be prevented during construction. Planters and other surface features, which could retain 19 g m Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SMIC of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 1rerracon temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. The soils to be penetrated by the proposed excavations may vary significantly across the site. The preliminary soil classifications are based solely on the materials encountered in widely spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope height. The exposed slope face should be protected against the elements. Additional Design and Construction Considerations • Exterior Slab Design and Construction Compacted subgrade or existing clay soils will expand with increasing moisture content; therefore, exterior concrete grade slabs may heave, resulting in cracking or vertical offsets. The potential for damage would be greatest where exterior slabs are constructed adjacent to the building or other structural elements. To reduce the potential for damage, we recommend: a exterior slabs be supported on fill with no, or very low expansion potential • strict moisture -density control during placement of subgrade fills • placement of effective control joints on relatively close centers and isolation - . joints between slabs and other structural elements • provision for adequate drainage in areas adjoining the slabs • use of designs which allow vertical movement between the exterior slabs and adjoining structural elements In those locations where movement of exterior slabs cannot be tolerated or must be reduced, consideration should be given to: • Constructing slabs with a stem or key -edge, a minimum of 6 inches in width and _I at least 12 inches below grade; • supporting keys or stems on drilled piers or screw piles; or 11 18 J Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SM/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Subgrade Preparation lrerrecon Subgrade soils beneath interior and exterior slabs should be scarified; moisture conditioned and compacted to a minimum depth of 12-inches below proposed controlled fill material. The moisture content and compaction of subgrade soils should be maintained until slab or pavement construction. Fill Materials and Placement Approved imported materials may be used as fill material and are suitable for use as compacted fill beneath interior or exterior floor slabs. Imported soils (if required) should conform to the following: Gradation Percent finer by weight (ASTM C136) 3"......................................................................................................... 100 No. 4 Sieve..................................................................................... 50-100 No. 200 Sieve.............................................................................. 35 (max) • Liquid Limit.................................................................................. 30 (max) • Plasticity Index............................................................................. 15 (max) • Group Index................................................................................. 10 (max) Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. It is recommended all fill material to be placed on the site be compacted to at least 95 percent of Standard Proctor Density (SPD) ASTM D698. On -site clay soils should be compacted .within a moisture content range of 2 percent below, to 2 percent above optimum. Imported granular soils should be compacted within a moisture range of 3 percent .below to 3 percent above optimum unless modified by the project geotechnical engineer. Excavation and Trench Construction Excavations into the on -site soils will encounter a variety of conditions. Excavations into the clays can be expected to stand on relatively. steep temporary slopes during construction. However, caving soils and groundwater may also be encountered. The individual contractor(s) should be made responsible for designing and constructing stable, 17 _ Geotechnical Engineering Report 1 McWhinney — Poudre Valley Hospital MOB SM/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Site Preparation 1rerrimm Strip and remove any existing debris, fill material and/or other deleterious materials from proposed building areas. All exposed surfaces should be free of mounds and depressions that could prevent uniform compaction. The site should be initially graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed building addition. Demolition of any existing medical office/clinic facility planned to be razed to accommodate the MOB structure or any auxiliary features to accommodate the new construction, should include complete removal of all foundation systems within the proposed construction area. This should include removal of any loose backfill found adjacent to existing foundations. All materials derived from the demolition of existing structure(s) and/or pavements should be removed from the site and not be allowed for use in any on -site fills. If unexpected fills or underground facilities are encountered, j such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. After all existing fill is removed, exposed areas, which will receive fill, once properly cleared where necessary, should be scarified to a minimum depth of 12-inches, conditioned to near optimum moisture content, and compacted. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. Based upon the subsurface conditions determined from the geotechnical exploration, the majority of the underlying subgrade soils exposed during construction are anticipated to be relatively stable; however soft compressible and/or unstable areas may be encountered during construction. The stability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unstable conditions develop, workability may be improved by scarifying and drying. Overexcavabon of wet zones and replacement with granular materials may be necessary. Use of lime, fly ash, kiln dust, cement or geotextiles could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction. Lightweight excavation equipment may be required to reduce subgrade pumping. 16 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SM/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lrerracon Placing curb, gutter and/or sidewalk directly on subgrade soils with the use of base course materials beneath. Preventive maintenance should be planned and provided for through an on -going pavement management program. Preventive maintenance activities are intended to slow the rate of pavement deterioration, and to preserve the pavement investment. Preventive maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching) and global maintenance (e.g. surface sealing). Preventive maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type and extent of preventive maintenance. Site grading is generally accomplished early in the construction phase. However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, or rainfall. As a result, the pavement subgrade may not be suitable for pavement construction and corrective action will be required. The subgrade should be carefully evaluated at the time of pavement construction for signs of disturbance or excessive rutting. If disturbance has occurred, pavement subgrade areas should be reworked, moisture conditioned, and properly compacted to the recommendations in this report immediately prior to paving. Please note that if during or after placement of the stabilization or initial lift of pavement, the area is observed to be yielding under vehicle traffic or construction equipment, it is recommended that Terracon be contacted for additional alternative methods of stabilization, or a change in the pavement section. Earthwork General Considerations The following presents recommendations for site preparation, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project. 15 Geotechnical Engineering Report McWhinney— Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lrenacon Each alternative should be investigated with respect to current material availability and economic conditions. Aggregate base course (if used on the site) should consist of a blend of sand and gravel, which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for base course. Aggregate base course should be placed in lifts not exceeding six inches and should be compacted to a minimum of 95% Standard Proctor Density (ASTM D698). Asphalt concrete pavement should be composed, of a mixture of aggregate, filler, binders, and additives, if required, and approved bituminous material in accordance with the LCUASS Pavement Design Criteria. The HMA should conform to an approved mix design stating the Hveem and/or Superpave properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in the HMA should meet particular gradations, such as the Colorado Department of Transportation Grading S, SX or SG specifications. Mix designs should be submitted prior to construction to verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and should be compacted to a within a range of 92 to 96 % of Maximum Theoretical Density. For areas subject to concentrated and repetitive loading conditions such as dumpster pads, truck delivery docks and ingress/egress aprons, we recommend using a Portland cement concrete pavement with a thickness of at least 7 inches underlain by at least 4 inches of aggregate road base material. Prior to placement of the aggregate road base material, the areas should be thoroughly proofrolled. For dumpster pads, the concrete pavement area should be large enough to support the container and tipping axle of the refuse truck. Long-term pavement performance will be dependent upon several factors, including maintaining subgrade moisture levels and providing for preventive maintenance. The following recommendations should be considered the minimum: • Site grading at'a minimum 2% grade away from the pavements; • The subgrade and the pavement surface have a minimum %< inch per foot slope to promote proper surface drainage. • Consider appropriate edge drainage and pavement under drain systems, • Install pavement drainage surrounding areas anticipated for frequent wetting (e.g. garden centers, wash racks) Install joint sealant and seal cracks immediately, • Seal all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils; • Placing compacted, low permeability backfill against the exterior side of curb and gutter; and, 14 Geotechnical Engineering Report McWhinney - Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lrerracan the pavement may be adequate from a structural standpoint, yet still experience cracking and deformation due to shrink/swell related movement of the subgrade. It is, therefore, important to minimize moisture changes in the subgrade to reduce shrink/swell movements. Recommended alternatives for flexible and rigid pavements, summarized for each traffic area, are as follows: RECOMMENDED MINIMUM PAVEMENT THICKNESS - INCHES (') HMA Surface HMA Surface Aggregate Base (2) Fly Ash 0 Structural Traffic Area Alternatives Grading S or Grading S or Course - Class 5 Treated Sub Fill CDOT PCC Total SX SG or 6 Base Class 7 (4) A 1.5 2.5 6.0 10.0 Automobile (5)B _ 1 3.5 6.0 12.0 21.5 Parking Areas - 20 (5) B _2 3.5 6.0 24.0 33.5 Year Design Life - 18 kip (4) C -1 4.0 6.0 10.0 EDLA 15 C-2 4.0 12.0 5.5 21.5 (4) A 1.5 3.0 7.0 11.5 Heavy Dutyfrruck Traffic Areas (5)B _ 1 3.5 6.0 12.0 21.5 - 20 Year (5) B -2 3.5 6.0 24.0 33.5 Design Life -18kip (4)C-1 4.0 6.5 10.5 EDLA 35 C-2 4.0 12.0 6.0 22.0 (1) If the HMA surface course is to consist of Grading SX the required minimum lift/thickness placed is 1-1/2-inches, for Grading S the minimum lift/thickness placed is 2-inches, and for Grading SG, the required minimum lift/thickness placed is 3-inches. (2) If fly ash is utilized for the on -site pavement improvement areas to mitigate the swell potential of the on -site subgrade materials, it is recommended that at least the upper 12-inches of the prepared subgrade be treated with fly ash. Terracon is available to provide the required laboratory soil and fly ash mix design as well as placement recommendations upon request. (3) For swell mitigation purposes, an alternative would be to overexcavated and replace the low to moderately expansive soils with a minimum thickness of 2-feet of CDOT Class 7 aggregate base course/structural fill material. (4) Alternative A and C-1 assumes a minimum of 2-feet of on -site soils have been either scarified or overexcavated, moisture conditioned and recompacted to at least 95 % of SPD, and an approved proof -roll has been completed. (5) Alternatives B-1 and B-2 provide the appropriate pavement thickness for either a fly ash or a structural fill replacement procedure for swell mitigation. Due to the properties of the existing cohesive on -site soils, full depth asphalt pavement is not recommended. 13 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 1rerracon potential and also enhances the structural integrity of the subgrade. This method may provide an excess of on -site soils for export. Chemical treatment, such as fly ash or lime. This procedure mitigates for expansive potential and enhances the structural integrity of the subgrade, as well as minimizes the exportation of soils. The third option involves over -excavating and reworking a minimum of 2-feet of the existing cohesive fill material. This requires the existing on -site subgrade section to be overexcavated and/or scarified a minimum depth of 2-feet below final subgrade elevation, moisture conditioned to plus or minus 2 percent of optimum moisture content and recompacted to at least 95 percent of Standard Proctor Density (SPD) ASTM D698. The intent of this procedure is to mitigate the expansive potential of the swelling materials; however due to the nature of cohesive soils, pumping conditions may develop causing unstable subgrade conditions. If unstable subgrade conditions occur, another means of stabilization will be necessary. The LCUASS Pavement Design Criteria provides guidelines for consultants conducting pavement evaluation - assessments when subgrade stabilization is necessary. This may include incorporation of a chemical treatment such as kiln dust, and/or fly ash to reduce the swell potential or an over -excavation and replacement with two (2) feet of non -to low expansive type soils. Due to the potential pumping conditions, which develop in a moisture treatment process, we recommend the use of fly ash. Incorporating into the upper 12-inches of the rough final subgrade soils with the use of a chemical treatment process, such as fly ash is recommended for this project. Proofrolling and recompacting the subgrade is recommended immediately prior to placement of the aggregate J road base section. Soft or weak areas delineated by the proofrolling operations should be undercut or stabilized in -place to achieve the appropriate subgrade support with additional fly ash if necessary. Hot Mix Asphalt (HMA) underlain by crushed aggregate base course with or without a fly ash treated subgrade, and non -reinforced concrete pavement are feasible alternatives for the proposed on -site paved sections. Based on the subsurface conditions encountered at the site, and the laboratory test results, it is recommended the on -site private drives and parking areas be designed using a minimum R-value of 10. Pavement design methods are intended to provide structural sections with adequate thickness over a particular subgrade such that wheel loads are reduced to a level the subgrade can support. The support characteristics of the subgrade for pavement design do not account for shrink/swell movements of an expansive clay subgrade such as the soils encountered on this project. Thus, 12 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20076039 lrerracan Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined below. • A minimum 6-inch layer of clean -graded gravel or aggregate base course should be placed beneath slabs on grade. Floor slabs should not be constructed on frozen subgrade. • Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1R are recommended. . Pavement Design and Construction (For Non -Jurisdictional On -Site Areas) Based on the subsurface conditions encountered during the site exploration, it is our opinion the proposed on -site pavement areas are feasible provided the following recommendations are implemented. The subsoils encountered throughout the site are generally plastictcohesive soils exhibiting low subgrade strength characteristics and low to moderate swell/expansive potential. This report provides recommendations to help mitigate the effects of soil shrinkage and expansion. Even if these recommendations are followed some pavement distress and exterior slab movement should be anticipated. Relatively undisturbed subsurface samples obtained at anticipated pavement subgrade elevations, revealed swell -index values greater than 2-percent when inundated with water at pre - loaded at 150 psf in accordance with Larimer County Urban Area Street Standards (LCUSS) Pavement Design Criteria, a guideline used to evaluate the pavement design recommendations. Swell -index test results in excess of 2-percent when inundated with water at a pre -loading scheme of 150 psf generally require a swell mitigation plan to reduce subgrade heave. Based.on our experience with similar soil conditions and the nature of the subsurface soil on -site, subgrade stabilization will be necessary prior to pavement procedures. Depending upon the time of year of construction and approval process of a passing subgrade proof roll, consideration should be given to a fly ash treatment procedure. If necessary, a fly ash treatment procedure should be incorporated into the subgrade section as a stabilization method to enhance the integrity of the underlying subsoils prior to placement of base course or Hot Mix Asphalt (HMA) materials. Terracon is providing herein three alternatives for swell mitigation and subgrade stabilization procedures in order of least to greater risk potential: Over -excavation of a minimum depth of 2-feet of existing cohesive material and replaced with approved imported granular structural fill. This procedure mitigates for expansive 11 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Terracon Terracon should be consulted to review preliminary load test data, and a representative of this firm should be present to observe. test and production screw pile installation to verify that proper bearing materials have been encountered during installation. Lateral Earth Pressures For soils above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements are: • Active: Cohesive soil backfill (on -site clay soils).................................45 psf/ft Cohesionless soil backfill (imported granular soils).................35 psf/ft On -site bedrock materials ...........................not recommended for use • Passive: Cohesive soil backfill (on -site clay soils)...............................250 psf/ft Cohesionless soil backfill (imported granular soils)...............350 psf/ft Drilled Piers..........................................................................500 psf/ft Where the design includes restrained elements, the following equivalent fluid pressures are recommended: At rest: Cohesive soil backfill (on -site clay soils).................................60 psf/ft Cohesionless soil backfill (granular imported soils).................50 psf/ft On -site bedrock materials ........................... not recommended for use The lateral earth pressures herein do not include any factor of safety and are not applicable for submerged soils/hydrostatic loading. Additional recommendations may be necessary if submerged conditions are to be included in the design. Fill against grade beams and retaining walls should be compacted to densities specified in Earthwork. Medium to high plasticity clay soils or claystone bedrock should not be used as backfill against retaining walls. Compaction of each lift adjacent to walls should be accomplished with hand -operated tampers or other lightweight compactors. Overcompaction may cause excessive lateral earth pressures, which could result in wall movement. 9 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lrerracan As part of the design phase and the determination of loading parameters, the installer can conduct an installation demonstration to the design team as they become more familiar with the expected subsurface conditions, (i.e. the depth to bedrock, drilled pier design parameters and groundwater conditions). The installer can also provide a site -specific load test to determine the achievable torque necessary to support the anticipated maximum wall and column loads for the Poudre Valley Hospital's MOB project. Terracon's design parameters for the use of drilled piers, which includes end bearing and skin friction characteristics as well as depth to bedrock, are presented in this geotechnical engineering report. The screw pile designer can design a screw pile foundation system to accommodate the maximum wall and column loads for the project based on the structural engineer's load design calculations as well as a pile cap/foundation wall system. The screw piles 1 will vary with depth from north to south and generally follow the bedrock contours. The screw piles should extend into the underlying bedrock formation sufficiently to achieve the design torque to support the anticipated loading parameters. A screw pile is installed to a design torque and not Jnecessarily a required depth of penetration into the bedrock. As long as the required torque is achieved the screw install is then terminated. Typically, depending upon the design loads as well as the design torque, a screw pile may only extend into the bedrock a few feet. The screw pile designer can design the screw pile system with the necessary pipe diameter, wall thickness, and helix flight configuration to accommodate the project. An experienced screw pile contractor should be consulted to review the Logs of Borings provided herein. Groundwater and variable depth to medium hard to very hard siltstone bedrock with intermittent sandstone lenses encountered at the site could result in pile installation difficulties. At a minimum, we recommend that test piles/load test procedures be conducted to determine the appropriate design parameters for the site, (i.e. tested for axial and lateral capacity prior to installing production piles). If lateral load testing cannot be performed, a sufficient number of battered piles should be installed to resist all lateral loading imposed. 1 The actual design of the piles including the pile capacity, spacing, helix diameter(s), shaft length, 1 bracket attachment and configuration, and shaft diameter should be performed by an experienced screw pile contractor and designed by a licensed structural engineer. As previously outlined, due to the relatively shallow depth to bedrock, an experienced screw pile contractor should review the data to assess whether heavy-duty equipment or pre -drilling will be required to achieve the minimum length and capacity. Screw piles should be considered to work in group action if the horizontal spacing is less than 3 pile diameters. A minimum practical horizontal spacing between piles of at least 3 diameters should be maintained, and adjacent piles should bear at the same elevation. The capacity of individual piles must be reduced when considering the effects of group action. Capacity reduction is a function of pile spacing and the number of piles within a group. If group action analyses are necessary, capacity reduction factors can be provided for the analyses. 1.1 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lferreazon Drilling most of the caissons should be possible with conventional single flight power augers within the weathered portions of the underlying bedrock formation. Areas of well -cemented sandstone bedrock will be encountered at increased depths where specialized drilling equipment and/or rock augers will be required. Consideration should be given to obtaining a unit price for difficult caisson excavation in the contract documents for the project. Groundwater was measured in each of the four deeper foundation related test borings at 1 approximate depths of 21 to 22-feet below site grades during initial drilling operations. Therefore J temporary casing will be required. The use of a tremie may be needed to adequately/properly drill and clean piers prior to concrete placement. Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete should be placed immediately after completion of drilling and cleaning. A maximum 3-inch depth of groundwater is acceptable in each pier prior to concrete placement. If pier concrete cannot be placed in dry conditions, a tremie should be used for concrete placement. Due to potential sloughing and raveling, foundation concrete quantities may exceed calculated geometric volumes. Pier concrete with slump in the range of 6 to 8 inches is recommended. If casing is used for pier construction, it should be withdrawn in a slow continuous manner d maintaining a sufficient head of concrete to prevent infiltration of water or the creation of voids in pier concrete. Foundation excavations should be observed by the geotechnical engineer. A representative of the geotechnical engineer should inspect the bearing surface and pier configuration. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. Alternative Foundation System — Steel Screw Piles An alternative foundation system to consider for this project, due to the depth to the underlying bedrock formation as well as the presence of groundwater, would be the use of steel screw piles. Due to the depth to groundwater as well as the necessity to case each drilled pier/caisson and also depending upon the time of year for construction, it is Terracon's opinion that the use of screw piles are a viable alternative for this site. There are several benefits for using a screw pile design concept versus a drilled pier in certain situations, especially in cases where the bedrock is encountered at depths greater than 20-feet below site grades and when groundwater is present. Depending on the contractor, a screw pile can be installed in less time than a drilled pier and there is no need for concrete or additional reinforcement. Casing is not necessary and the screw pile(s) can also be loaded up to approximately 500 kips per location, or a series of screw piles can be installed to achieve a greater concentrated loading arrangement as well as to resist laterally loaded conditions. 7 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lemon All piers should be reinforced full depth for the applied axial, lateral and uplift stresses imposed. The tensile force created by the uplift force on each pier, with allowance for dead load, should determine the amount of reinforcing steel for expansion. To satisfy forces in the horizontal direction, piers may be designed for lateral loads using a modulus of 75 tons per square foot for the portion of the pier in clays and/or engineered fill, and 400 tsf in bedrock for a pier diameter of 12 inches. The coefficient of subgrade reaction for varying pier diameters is as follows: C Q � �S��i1,WIUt S i'vClfx g1 7').1 ,Ie�"�Fa�►eter�((nches) � ✓4 Sl "� , ',y ril'�y 5 ti..x�+{ s.�r! Coefficient,ofsSubg�aderF�eactlon�(ton � �;r • �d;r�� ��� � , u , )4Nt� rlj� 31 !,� 1 ^ i.l V f, ft r) > , +, � �� n� +,w ra � � Englnee&&Flll,or Stlff Clays v ;Bedrock , s> 18 50 267 24 38 200 30 30 160 36 25 133 48 18 100 When the lateral capacity of drilled piers is evaluated by the L-Pile (COM 624) computer program, we recommend that intemally generated load -deformation (P-Y) curves be used. The following parameters may be used for the design of laterally loaded piers, using the L-Pile (COM 624) computer program: Parameters Compacted On -Site Overburden Bedrock Structural Fill Cohesive Soils Unit Weight of Soil (pcf) 130 1150) 125(') Cohesion (psf) 0 1500 5000 Angle of Internal Friction O 35 25 20 (degrees) Strain Corresponding to 'Y2 Max. — 0.02 0.015 Principal Stress Difference w "Notes: 1) Use of 65 PCF below the water table To reduce potential uplift forces on piers, use of long grade beam spans to increase individual pier loading, and small diameter piers are recommended. For this project, use of a minimum pier diameter of 24-inches is recommended. Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lferra<on exploration, 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. Zones of perched and/or trapped groundwater may occur at times in the subsurface soils overlying bedrock, on top of the bedrock surface or within permeable fractures in the bedrock materials. The location and amount of perched water is dependent upon several factors, including hydrologic conditions, type of site development, irrigation demands on or adjacent to the site, fluctuations in water features, seasonal and weather conditions. Based upon review of U.S. Geological Survey maps ('Hillier, et al, 1983), regional groundwater is expected to be encountered in unconsolidated alluvial deposits on the site, at depths ranging from 10 to 20 feet below the existing ground surface at the project site. ENGINEERING ANALYSES AND RECOMMENDATIONS Geotechnical Considerations The site appears suitable for the proposed construction from a geotechnical engineering point of view. Due to on -site subsurface conditions, complexity of the project, foundation bearing levels, and structural loads, the following foundation system was evaluated for use on the site: Grade beams and straight shaft drilled piers/caissons extending into the underlying bedrock formation; and • Steel Screw Piles installed into the underlying bedrock formation to design torque values established during a "pre -design" load -test demonstration. Foundation Systems — Drilled Piers/Caissons Due to the anticipated loading conditions for the proposed Poudre Valley Hospital's 4-story Medical Office Building structure, it is recommended that a grade beam and drilled pier/caisson foundation system be used to support the proposed structure. Straight shaft piers, drilled a minimum of 10- feet into competent or harder bedrock, with minimum shaft lengths of 25-feet are recommended and should be designed using a maximum end bearing of 45,000 psf, along with a skin friction of 4,500 psf. The drilled piers should also be designed to maintain a minimum dead load of 5,000 psf. I Hillier, Donald E.; Schneider, Paul A., Jr.; and Hutchinson, E. Carter, 1983, Depth to Water Table (1979) In the Boulder - Fort Collins -Greeley Area, Front Range Urban Corridor, Colorado, United States Geological Survey, Map 1-855-I. A Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Nerrazon approximately 3 to 4-inches of existing aggregate base course. Underlying the pavement layers in each boring was sandy lean clay with trace amounts of gravel fill material, which extended to the native subsoils below. The native sandy lean clay and/or lean clay strata were encountered at approximate depths of 2 to 2-1/2-feet below site grades and extended to the fine to coarse granular strata below. Silty sand and silty sand with gravel was encountered in each boring at approximate depths of 22 to 23-feet below site grades and extended to the bedrock below. Sandstone/siltstone bedrock with intermittent cemented sandstone lenses was encountered in each of the deeper foundation related test borings at approximate depths of 30 to 32-feet below site grades and extended to the depths explored, approximately 44-1/2-feet y below site grades. Field and Laboratory Test Results Field and laboratory test results indicate the native cohesive clay at shallow depths are soft to stiff in consistency, exhibit low to moderate swell potential and low to moderate bearing characteristics. The fine to course granular strata is medium dense to dense in relative density and exhibits non -expansion potential and moderate bearing characteristics. The bedrock stratum varies from moderately hard to very with increasing depths and generally exhibits_ a low to moderate swell potential and moderate to high bearing characteristics. The existing on -site fill material is not suitable for support of footings or floor slabs without over excavating, moisture conditioning and recompacting to the specifications contained in the "Earthwork" section of this report. The competent bedrock with interbedded sandstone lenses revealed Standard Penetration Test (SPT — N Blows/foot) results with increased depths within the cemented lenses of approximately 50 blows with a 140-pound hammer falling 30-inches, penetrating 1 to 8-inches. The hard, well cemented sandstone lenses at increased depths throughout the site may require the use of specialized heavy-duty equipment to achieve designed elevations. Excavations penetrating the well -cemented bedrock may require the use of a rock hammer or core barrel to achieve final design elevations. Consideration should be given to obtaining a unit price for difficult excavation in the contract documents for the project. Groundwater Conditions Groundwater was measured in each of the test borings at approximate depths of 21 to 22-feet below site grades within the deeper foundation related test borings during the initial field exploration activities. Upon completion of the drilling operations the test borings were backfilled with auger cuttings for safety purposes; therefore, stabilized groundwater measurements were not obtained. These observations represent groundwater conditions at the time of the field 1 4 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB SIW/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 lferrxon penetration resistance value is a useful index in estimating the consistency, relative density or hardness of the materials encountered. Laboratory Testing J All samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer and were classified in accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Bedrock Classification. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A. Laboratory tests were conducted on selected soil samples and are presented in Appendix B. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. All laboratory tests were performed in general accordance with the applicable local or other accepted standards. Selected soil and bedrock samples were tested for the following engineering properties: Water Content • Plasticity Index • Dry Density • Grain -Size Distribution • Swell -Consolidation SITE CONDITIONS The site for the proposed 4-story slab on grade MOB structure is situated on the south side of Garfield Street and west of Lemay Avenue. The majority of the site is currently occupied by an existing asphalt paved parking area with a medical clinic office building situated near the northwest portion of the site. We understand this building is to be razed to accommodate the MOB structure. Robertson Street borders the site to the west with the Lemay Medical Park located beyond and the proposed parking garage structure along with existing business establishments are located to the north. The existing Lemay Avenue PVH building is located on the east side of Lemay Avenue directly across from the proposed MOB structure. 1 SUBSURFACE CONDITIONS Soil and Bedrock Conditions The subsurface conditions encountered within the 7 test borings drilled to date, generally consisted of an approximate 4 to 5-inch layer of existing asphalt pavement underlain by I3 Geotechnical Engineering Report McWhinney — Poudre Valley Hospital MOB S/W/C of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 Terrazan An existing building is located within the western portion of the site, in which 2 test borings are recommended by the project design team for pavement evaluation purposes. Our intent is to conduct a supplemental exploration after the building has been razed and the demolition complete. Although final site grading plans were not available at the time of the preparation of this report, it is assumed first floor level will be at or slightly above existing site grade elevations. SITE EXPLORATION The scope of the services performed for this project included a site reconnaissance by an engineering geologist, a subsurface exploration program, laboratory testing and engineering analyses. Field Exploration At this time a total of seven (7) were drilled on May 3, 20007 to approximate depths of 10 to 44- 1/2-feet below existing site grades, at the locations as shown on the enclosed Test Boring Location Diagram, Figure No. 1. Test Borings labeled BB1 through BB4 were foundation related borings and were extended to an approximate depth of 44-1/2-feet below site grades. During our initial field exploration for he proposed parking garage structure planned to the north, a test boring was drilled for an initially proposed stair tower structure. This boring, with the new conceptual layout is within the northeastern portion of the proposed MOB structure and we are including the information from Test Boring No. 9 herein. The borings labeled SB 3 through SB 5 are site borings for pavement evaluation analyses. As previously mentioned, SB 1 and SB 2 will be drilled when the existing building situated within the northwestern portion of the site has been razed. The borings were advanced with a truck -mounted drilling rig, utilizing 4-inch diameter solid stem and 3- 1/4-inch inside diameter hollow stem augers. The borings were located in the field by using a hand held GPS unit and referenced to existing site features. Approximate ground surface elevations were estimated at each boring location by use of an engineer's level and referenced to a temporary benchmark (TBM), which consisted of the finish floor elevation of the existing hospital building, assuming an elevation of 4,974. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used. Lithologic logs of each boring were recorded by the engineering geologist during the drilling operations. At selected intervals, samples of the subsurface materials were taken by means of driving split -spoon and/or ring -barrel samplers. Penetration resistance measurements were obtained by driving the split -spoon or ring barrel sampler into the subsurface materials with a 140-pound hammer falling 30 inches. The VA GEOTECHNICAL ENGINEERING REPORT PROPOSED POUDRE VALLEY HOSPITAL — MEDICAL OFFICE BUILDING 1024 SOUTH LEMAY AVENUE CAMPUS SOUTHWEST CORNER OF GARFIELD STREET AND SOUTH LEMAY AVENUE FORT COLLINS, COLORADO TERRACON PROJECT NO.20075039 MAY 14, 2007 INTRODUCTION This report contains the results of our geotechnical engineering exploration for the 4-story Medical Office Building (MOB) structure and associated pavement areas, to be constructed at the northwest comer of Lemay Avenue and Garfield Street for the existing Poudre Valley Hospital's Lemay Avenue Campus in Fort Collins, Colorado. The site is located in the Southeast 1/4 of Section 13, Township 7 North, Range 69 West of the 6th Principal Meridian, Larimer County, Fort Collins, Colorado. The purpose of the geotechnical engineering related services is to provide information and preliminary geotechnical engineering recommendations relative to: • subsurface soil and bedrock conditions • groundwater conditions • foundation design and construction • floor slab design and construction • pavement design construction • earthwork • drainage The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, and experience with similar soil conditions, structures and our understanding of the proposed project. PROPOSED CONSTRUCTION The project as we understand, is to construct an approximate 60,000 square foot, 4-story, slab on grade, multi -tenant MOB structure south of the proposed parking garage structure, and situated at the southwest corner of South Lemay Avenue and Garfield Street, directly west of the existing I Lemay Avenue PVH Campus. We anticipate the maximum wall and column loads for the PVH new MOB structure to be on the order of 1 to 6 kips per linear foot, and 75 to 500 kips respectively. Geotechnical Engineering Report Twamn McWhinney — Poudre Valley Hospital MOB SIWIC of Lemay Avenue and Garfield Street Fort Collins, Colorado Project No. 20075039 APPENDIX A Figure No. 1 — Test Boring Location Diagram Test Boring Logs APPENDIX B Laboratory Test Results APPENDIX C General Notes iv TABLE OF CONTENTS Page No. Letterof Transmittal..............................................................................................i INTRODUCTION..................................................................................................................1 PROPOSED CONSTRUCTION............................................................................................1 SITEEXPLORATION...........................................................................................................2 FieldExploration.......................................................:..................................................2 LaboratoryTesting....................................................................................................... 3 SITECONDITIONS..............................................................................................................3 SUBSURFACE CONDITIONS..............................................................................................3 Soil and Bedrock Conditions........................................................................................3 Field and Laboratory Test Results...............................................................................4 Groundwater Conditions..............................................................................................4 J ENGINEERING ANALYSES AND RECOMMENDATIONS...................................................5 Geotechnical Considerations.......................................................................................5 1 Foundation Systems — Drilled Piers/Caissons............................................................. 5 j Foundation Systems — Screw Piles.............................................................................. 7 Lateral Earth Pressures..........:....................................................................................9 Seismic Considerations.............................................................................................10 Floor Slab Design and Construction..........................................................................10 Pavement Design and Construction..........................................................................10 Earthwork..................................................................................................................15 General Considerations....................................................................................15 SitePreparation...............................................................................................16 Subgrade Preparation......................................................................................17 Fill Materials and Placement.............................................................................17 Excavation and Trench Construction................................................................17 Additional Design and Construction Considerations..................................................18 Exterior Slab Design and Construction.............................................................18 Corrosion Protection.........................................................................................19 Underground Utility Systems............................................................................19 J Surface Drainage.............................................................................................19 General Considerations for Fly Ash.................................................................. 20 GENERALCOMMENTS.....................................................................................................20 May 14, 2007 McWhinney 2725 Rocky Mountain Avenue — Suite 200 Loveland, Colorado 80538 Attn: Mr. Dean Barber, Vice President of Construction Irerracon Consulting Engineers & Scientists Re: Geotechnical Engineering Report Proposed Poudre Valley Hospital — Medical Office Building (MOB) 1024 South Lemay Avenue Campus Southwest Comer of Garfield Street and South Lemay Avenue Fort Collins, Colorado y Terracon Project No. 20075039 301 North Howes Fort Collins, Colorado 80521 Phone 970.484.0359 Fax 970.484.0454 www.terracon.com Terracon has completed a geotechnical engineering exploration for the proposed 4-story Medical Office Building (MOB) structure and associated pavement areas, to be constructed at the northwest comer of Lemay Avenue and Garfield Street for the existing Poudre Valley Hospital's Lemay Avenue Campus in Fort Collins, Colorado. This study was performed in general accordance with our Proposal No. D2007183 dated April 24, 2007. The results of our engineering study completed for the proposed MOB structure including the boring location diagram, test boring records, and the geotechnical recommendations needed to aid in the design of foundations, floor slabs, and other earth connected phases of this project are attached. We appreciate being of service to you in the geotechnical engineering phase of this project, and are prepared to assist you during the construction phases as well. If you have any questions concerning this report or any of our testing, inspection, design and consulting services, please do not hesitate to contact us. Sincerely, TERRACON David A. Richer, P.E. ' Geotechnical Engineer/Department Manager Doug J. Jobe, P.E. Geotechnical Engineer/Regional Manager Copies to: Addressee (4) PVHS System Development (2): Mr. Troy Martin Delivering Success for Clients and Employees Since 1965 More Than 80 Offices Nationwide GEOTECHNICAL ENGINEERING REPORT PROPOSED POUDRE VALLEY HOSPITAL — MEDICAL OFFICE BUILDING 1024 SOUTH LEMAY AVENUE CAMPUS SOUTHWEST CORNER OF GARFIELD STREET AND SOUTH LEMAY AVENUE FORT COLLINS, COLORADO TERRACON PROJECT NO.20075039 MAY 14, 2007 Prepared for. McWhinney 2725 Rocky Mountain Avenue — Suite 200 Loveland, Colorado 80538 Attn: Mr. Dean Barber, Vice President of Construction Prepared by. Terracon 301 North Howes Street Fort Collins, Colorado 80521 � � Irerrac