Appendix_B.pdf

American GeoServices Geotechnical Evaluation Report

Proposed Military Working Dog Kennel Facility Peterson Airforce Base, Colorado Springs, CO

Original Date: December 18, 2017 Revision Date: January 7, 2018 Project No: 0401-CS17

2663 CINNABAR ROAD, COLORADO SPRINGS, CO 80921; PH: (719) 761-6072

MAILING ADDRESS: 191 UNIVERSITY BLV 375 DENVER, CO 80206 PH: (303) 325-3869

December 18, 2017 Revised January 7, 2018

PROJECT NO: 0401-CS17

Mr. Shane Matt, FourFront Design, Inc.

517 Seventh Street Rapid City, SD 57701

Reference: Geotechnical Evaluation Report, Peterson AFB Military Working Dog Kennel Facilities, FourFront Design, Inc. Project No. 14.2205.A04

A detailed Geotechnical Evaluation Report No. 0401-CS17 dated December 18, 2017 was submitted to you. Subsequently, we received review comments from you and Mr. Joel Simonyak, the project architect. Based on the results of our evaluation of the review comments and additional analyses, we submit the following revised geotechnical report.

PROJECT INFORMATION

The site is located south of Hwy 94 and west of Peterson Road as shown in Figure 1 through Figure 5. The site is roughly a rectangular-shaped barren parcel of land situated inside the Peterson Air Force Base in Colorado Springs, Colorado. Site topography is relatively flat to gently sloping downwards towards the south or south-east.

The proposed development will consist of building a single-story structure. We do not anticipate significant site grading or basement for this project. We anticipate proposed structures will be constructed with light to moderate foundation loads. If these proposed conditions change, we should be contacted to modify our report.

SCOPE OF WORK

During December 2017, eight Standard Penetration Test (SPT) borings (B1 through B8) were drilled in the proposed construction area at locations shown in Figure 6. Using a CME 55 equivalent drill rig, SPT borings were extended to the maximum exploration depth of

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Revised January 7, 2018 Page No: 2 of 15 approximately 25 feet below the existing ground surface. The drill rig was equipped with 4.0-inch diameter, solid-stem continuous-flight augers. The augers were used to advance the boreholes and samples were obtained using a 2-inch, outside-diameter split-spoon sampler. The sampler was driven using a standard hammer weighing 140 pounds falling a distance of 30 inches. The sampler was first seated into the bottom of the borehole, and then driven 12 inches. The number of blows required driving the sampler 12 inches, or a fraction thereof, constitutes a penetration test and is similar to the SPT testing standards as per American Society for Testing and Materials ASTM D1586. The penetration tests, when properly evaluated, provide an index to the soil strength and density of the material tested. The penetration test results are shown on the individual Borehole Log included in an Appendix. The Legend and Notes necessary to interpret our Borehole Logs are also included in an appendix.

After the completion of drilling, all boring locations were backfilled with soil cuttings. Remaining soil cuttings were removed from the site and the entire site was left clean.

Samples of subsurface soil materials were collected at regular intervals during drilling. The samples were visually inspected, logged, placed in a sealed container, and transported to testing laboratory for further visual evaluation. Groundwater level measurements were taken during drilling and after the completion of drilling. Besides visual observation, soil classification and moisture content determination, and Atterberg Limits testing, other soil laboratory tests/evaluation were not deemed necessary. Results of laboratory tests are included in an appendix.

Data obtained from site observations, subsurface exploration, laboratory evaluation, and previous experience in the area was used to perform engineering analyses. Results of engineering analyses were then used to reach conclusions and recommendations presented in this report.

SUBSURFACE CONDITIONS

Subsurface conditions encountered in our boreholes B1 through B8 are described in detail in the Borehole Logs provided in an Appendix. Soil classification and identification are based on commonly accepted methods employed in the practice of geotechnical engineering. In some cases, the stratigraphic boundaries shown on Borehole Logs represent transitions between soil types rather than distinct lithological boundaries. It should be recognized that subsurface conditions often vary both with depth and laterally between individual borehole locations. The following is a summary of the subsurface conditions encountered at the site:

Topsoil: Topsoil was encountered at the site in upper 2-4 inches.

Native Alluvium: Topsoil was underlain by generally loose to medium dense sands to clayey sands (SP, SC) with trace to some gravels, and trace silt, extending to the maximum explored depth of 25 feet below ground surface (BGS). Laboratory testing of these soils revealed moisture

Revised January 7, 2018 Page No: 3 of 15 contents in the range of 7.0-13.5%. These soils were non-plastic. Sandy clays (SC) were generally noted below depths of 19-21 feet.

Groundwater: Groundwater was not encountered during or after the completion of drilling. These observations may not be indicative of other times or at locations other than the site. Some variations in the groundwater level may be experienced in the future. The magnitude of the variation will largely depend upon the duration and intensity of precipitation, temperature and the surface and subsurface drainage characteristics of the surrounding area.

Seismicity: Based on the results of our subsurface explorations and review of available literature (current International Building Code), in our opinion, a site classification “D” may be used for this project. However, this site classification may be revised by performing a site-specific shear wave velocity study. We do not anticipate seismically induced liquefaction potential at the site.

PERCOLATION TEST RESULTS

In December 2017, two percolation tests were performed at depths ranging from 2-3 feet.

Percolation tests P1 and P2 were performed at Borehole Locations B2 and B8, respectively, in general accordance with El Paso County percolation test procedures and US EPA-625/1-80-012 test procedure. Boreholes B2 and B8 were used as the profile test holes, and the percolation tests were performed prior to extending the boreholes to full depth. Percolation test holes were made at least 6 inches in diameter. In addition, following available soils literature and public domain websites were reviewed on the site vicinity area:

• Soil Survey of El Paso County, USDA, SCS

• Geology of Colorado, USGS

• Geologic Maps, Colorado Geological Survey

• USGS Topographic Maps.

• U.S. Geological Survey, Open File Reports

• El Paso County, GIS

Available NRCS soil survey map data (Web Soil Survey) revealed that the potential storm water treatment or BMP area and the site is generally underlain by ‘Truckton Sandy Loam, 0 to 3 percent slopes. This soil is classified as ‘well-drained.’ The following is a summary of percolation test results:

Revised January 7, 2018 Page No: 4 of 15

Test Location Test Depth

Field Percolation

Rates

Soil Type

B2 24” 18 minutes / inch 2 B8 36” 20 minutes / inch 2

Notes:

1. Groundwater table or any restrictive soil layer was not encountered.

2. Soil conditions are similar throughout the site as per the Soil Survey Map and subsurface investigation, therefore, same infiltration rate may be used for the whole site.

GEOTECHNICAL CONSIDERATIONS

The site is suitable for the proposed construction provided following recommendations are strictly followed. It should be noted that our recommendations are intended as guidance. They are based on our interpretation of the geotechnical data obtained during our evaluation and following assumptions:

• Proposed/Final site grades will not differ significantly from the current site grades;

• Proposed foundations will be constructed on level ground; and

• Structural loads are static in nature.

Following construction recommendations are provided to highlight aspects of construction that could affect the design of the project. Entities requiring information on various aspects of construction must make their own interpretation of the subsurface conditions in order to determine construction methods, cost, equipment, and work schedule.

CONVENTIONAL SHALLOW FOUNDATION

The proposed structures can be supported on conventional shallow foundations provided following conditions are met. If these conditions cannot be met, then we should be contacted to provide specific recommendations or to modify following recommendations:

• All footings should be embedded at least 3 feet from all sides and should not be subjected to any temporary flooding from any water in the swales or detention facilities.

• Excavate the foundation subgrades and surficially compact the excavated subgrade with a vibratory plate compactor, and then call AGS for open-hole inspection.

• Once the compacted foundation subgrades are inspected and approved by AGS, install adequate reinforcement and perimeter/foundation drains (optional) as shown in Figure 7 & Figure 8. All drainage systems should be discharged into suitable receptacles. Positive drainage away from buildings must be maintained at all times.

Revised January 7, 2018 Page No: 5 of 15

• Pour concrete only after all foundation subgrades and foundation drains are inspected and approved by a registered geotechnical engineer.

• Provided above recommendations are strictly followed, foundations can be designed for a maximum allowable bearing capacity of 1,500 pounds per square foot (psf). For lateral load resistance, passive earth pressure value of 300 pcf equivalent fluid density may be used. A coefficient of friction value of 0.4 (unfactored) may be used for concrete foundation against sandy subgrade.

• Estimated final structural loads will dictate the final form and size of foundations to be constructed. However, as a minimum, we recommend bearing walls be supported by continuous footings of at least 18 inches in width. Isolated columns should be supported on pads with minimum dimensions of 24 inches square.

• Continuous or strip foundations should be reinforced in the top and bottom to span an unsupported length of at least 8 feet to further aid in resisting differential movement. See Figure 7.

We estimate total settlement for foundations designed and constructed as discussed in this section will be one inch or less, with differential settlements on the order of one-half to three-fourths of the total settlement.

SLAB-ON-GRADE

The “Slab Performance Risk” associated with existing sandy soils is “Low.” Slab-on-grade is a viable option, however, the owner should be aware that there is always some potential risk associated with slab movement. A structural slab or a PTS slab is always a more reliable option, especially if the owner is not willing to assume any risk.

The actual slab movements that will occur on a particular project site are very difficult, if not impossible, to predict accurately because these movements depend on loads, evapo-transpiration cycles, surface and subsurface drainage, and settlement / collapse characteristics.

The actual time of year during which the slab-on-grade is constructed has been found to have a large influence on future slab-on-grade movements.

Slab settlements are normally defined in terms of "total" and "differential" movement. "Total" movement refers to the maximum amount of settlement that the slab may experience as a whole.

"Differential" movement refers to unequal settlement that different points of the same slab may experience, sometimes over relatively short horizontal distances. Differential movements are arbitrarily determined to be one-half of the total movement in soils exhibiting Low Slab Performance Risk. Greater differential movements can occur in areas where loess soils have been encountered and where the natural soils abruptly transition to fill material.

Revised January 7, 2018 Page No: 6 of 15

For design of floor slabs, a modulus of subgrade reaction of 200 pounds per cubic inch (pci) may be used provided slab-on-grade is placed on properly prepared subgrades after the completion of soil modification procedures described earlier.

We recommend that the construction measures outlined in the following paragraphs be followed to reduce potential damage to floor slabs, should wetting of the subsurface soils occur:

• Separate floor slab from all bearing walls and columns with expansion joints to allow unrestrained vertical movement. In general, floor slab should not extend beneath exterior doors or over foundation grade beams without saw cutting the slab at the beam after construction. However, saw-cutting and isolating the slab can be eliminated provided the slab is adequately reinforced to control the location and the extent of cracking, to bridge over localized settled spots due to any localized hydro-compaction of sandy soils. We do not anticipate localized settled spots to be longer than 8 feet, if any. The low potential for hydro-compaction of onsite sandy soils was discussed in earlier paragraphs.

• Provide slip joints around exterior walls, interior non-bearing partitions.

• The connections between the interior, slab-supported partitions and exterior foundation supported walls should allow for differential movement. For slab-bearing masonry block partitions, provide slip joints at the top of the walls. Notwithstanding, if the floor moves, the partition walls may still show signs of structural distress such as cracking.

• If partition walls, masonry block walls, or any other walls without bottom slip joints are required, it is best to support them on grade beams which are, in turn, supported on piers.

In other words, construct the slab independent of all foundations.

• If options are not available and slab-bearing partition walls are necessary, then the potential for structural distress may be reduced by connecting the partition walls to exterior walls using slip channels.

• Frequent control joints should be provided at about 10 feet spacing in the floor slab to reduce problems with shrinkage and cracking according to ACI specifications. Control joint spacing is a function of slab thickness, aggregate size, slump and curing conditions. The requirements for concrete slab thickness, joint spacing, and reinforcement should be established by the designer, based on experience, recognized design guidelines and the intended slab use. Placement and curing conditions will have a strong impact on the final concrete slab integrity. Floor slabs should be adequately reinforced.

• The need for a vapor barrier will depend on the sensitivity of floor coverings to moisture.

If moisture sensitive floor coverings are proposed for portions of the proposed structure, a capillary break material, typically consisting of a “clean” gravel, should be considered.

We can provide additional recommendations if this is the case.

Vapor barrier may be placed directly underneath the slab, provided the project architect and structural engineer evaluate the possibility of curling of slab, adverse impact on

Revised January 7, 2018 Page No: 7 of 15 floorings due to moisture imbalance, and the adverse impact (increased drying time or moisture migration upwards) on the drying of the poured concrete slab.

• Provided gravel is desired below the slab, a layer of 4 to 6 inches can be used. Plumbing passing through slabs should be isolated from the slabs and provided with flexible connections to allow for movement. A positive bond break should be provided where plumbing lines enter through the slab. Under slab, plumbing should be avoided if possible and should be brought above the slab as soon as possible.

• Where mechanical equipment and HVAC equipment are supported on slabs, we recommend provision of a flexible connection between the furnace and ductwork with a minimum of 1.5 inches of vertical movement.

• Sidewalks and other exterior flatwork should be separated from the slab and the slab should be designed as an independent unit.

RETAINING WALLS

We do not anticipate the use of basement walls on this project. In any case, foundation walls, and basement walls, if used, should be designed to be rigid (unyielding), and not free to rotate.

Retaining walls for at-rest conditions can be designed to resist an equivalent fluid density of 50 pcf for on-site materials. If needed, only imported granular backfill meeting CDOT Class 1 structural backfill should be used. Retaining walls for unrestrained conditions (free lateral movement) can be designed to resist an equivalent fluid density of 45 pcf for on-site fill materials and 35 pcf for imported granular backfill or CDOT Class 1 structural backfill. For passive resistance of unrestrained walls, we recommend passive resistance of 300 psf per foot of wall height. A coefficient of friction value of 0.35 may be used for contact between the prepared soil surface and concrete base.

The above recommended values do not include a factor of safety or allowances for surcharge loads such as adjacent foundations, sloping backfill, vehicle traffic, or hydrostatic pressure. The above recommended values do not include hydrostatic pressures as they are based on drained conditions. We should be contacted to provide additional recommendations for any specific site retaining conditions.

Retaining wall backfill should be placed in strict accordance with our earthwork recommendations given below. Backfill should not be over-compacted to minimize excessive lateral pressures on the walls. As a precautionary measure, a drainage collection system (drains or geosynthetic drains) should be included in the wall design to minimize hydrostatic pressures. A prefabricated drainage composite or drain board such as the MiraDrain 2000 or an engineer-approved equivalent may be installed along the backfilled side of the basement foundation wall.

Revised January 7, 2018 Page No: 8 of 15

SUBSURFACE DRAINAGE

High groundwater was not encountered during or after the completion of drilling. Nevertheless, proper subsurface drainage is critical for long-term performance of the proposed structures. As a minimum, recommendations illustrated in Figure 8 and given below should be strictly followed.

• A perimeter drain/dewatering system should be installed to reduce the potential for groundwater entering the foundation and slab areas. The lot-specific perimeter dewatering systems should be properly designed and connected to the suitable discharge from the lot.

• As a minimum, the subsurface drainage system should consist typically of 4-inch minimum diameter perforated rigid PVC pipe surrounded by at least one pipe diameter of free draining gravel. The pipe should be wrapped in a geosynthetic to prevent fine soils from clogging the system in the future. The pipe should drain by gravity to a suitable all-weather outlet or to a properly designed area underdrain system. If an outlet or area underdrain is not available, the subsurface drainage system should be sloped to sump pits with sump pumps having standby capacity in the event of pump failure.

• Surface cleanouts of the perimeter drain should be installed at minimum serviceability distances around the addition. A properly constructed drain system can result in a reduction of moisture infiltration of the subsurface soils. Drains which are improperly installed can introduce settlement of the subsurface soils and could result in improper surface grading only compounding the potential issues.

• The entire design and construction team should evaluate, within their respective field of expertise, the current and potential sources of water throughout the life of the structure and provide any design/construction criteria to alleviate the potential for moisture changes.

If recommended drain systems are used, the actual design/layout, outlets, and location should be designed by AGS. The construction means and methods should be observed by a representative of AGS.

SURFACE DRAINAGE

Proper surface drainage should be maintained at the site during and after completion of construction operations. Based on the intended use of the proposed facility, all drainage recommendations provided local, state, and federal regulatory agencies should be strictly followed. As a minimum, recommendations illustrated in Figure 8 and given below should be implemented.

• It is important to follow these recommendations to minimize wetting or drying of the foundation elements throughout the life of the facility. Construction means and methods should also be utilized which minimize improper increases/decreases in the moisture contents of the soils during construction.

Revised January 7, 2018 Page No: 9 of 15

• The ground surface adjacent to buildings should be sloped to promote rapid run-off of surface water. We recommend a minimum slope of six inches in the first five horizontal feet for landscaped or graveled areas. These slopes should be maintained during the service life of buildings.

• Landscaping should be limited around building areas to either xeri-scaping, landscaping gravel, or plants with low moisture requirements. Irrigation should be minimal and limited to maintain plants. Roof downspouts should discharge on splash-blocks or other impervious surfaces and directed away from the building. Ponding of water should not be allowed immediately adjacent to the building.

• Upper 2 feet of exterior grading or landscaping fill placed immediately adjacent to the building (within 10ft) should be relatively impervious to minimize water infiltration adjacent to the building. Do not use plastic membrane in lieu of impervious fill to cover the ground surface.

• Again, positive drainage away from the new structures is essential to the successful performance of foundations and flatwork, and should be provided during the life of the structure. Paved areas within 10 feet of structures should slope at a minimum of 2 percent away from foundations, and landscape areas within 10 feet of structures should slope away at a minimum of 8 percent.

• Downspouts from all roof drains, if any, should cross all backfilled areas such that they discharge all water away from the backfill zones and structures. Drainage should be created such that water is diverted away from building sites and away from backfill areas of adjacent buildings.

OPTIONAL- ELIMINATION OF FOUNDATION DRAIN AND IMPERVIOUS FILL

The foundation drain and the placement of impervious fill around the foundations can be completed eliminated, provided the owner is willing to assume a low risk of future differential movement (approximately 0.75 inches). This risk exists at the site, due to the following site conditions:

a. As illustrated in Figure 4, the site is located extremely close to the mapped Collapsible Soils Hazard Zone to the east. Although collapsible soils were not encountered in any of the boreholes, it is possible to have localized pockets of collapsible soils, especially considering the proximity to the Collapsible Soils Hazard Zone. Moreover, the site is underlain by sandy alluvial material which are also somewhat susceptible to hydro-compaction resulting from flooding, snow-melt, freeze-thaw, and excessive or unusual rainfall.

b. Due to the cold climate and the presence of trace amounts of silt within sandy soil matrix, there is also a small possibility of adverse impact on the bearing capacity resulting from

Revised January 7, 2018 Page No: 10 of 15 frost action or freeze-thaw cycles, and minor frost-heave. It should also be noted that the on-site soils are classified as having moderate potential for frost-action (USCS, El Paso County, CO).

c. As illustrated in Figure 5, the site is located extremely close to the mapped Flood Hazard Zone to the west. Although the potential is very low, the on-site soils can be subjected to saturation due to the proximity to the Flood Hazard Zone and subsequent hydro compaction of sandy soils.

d. The absence of impervious fill around the foundation may result in faster movement of water towards the foundations, further increasing the possibility of hydro-compaction of soils, reduction of bearing capacity, or punching shear failure, or localized loss of support of shallow footings.

e. In general, recommendations given for the bearing capacity (along with a settlement criteria) assume of ‘uniform moisture conditions.’ Elimination of foundation drains and impervious cover adjacent to the footings may adversely impact the ‘uniform moisture conditions’ assumption.

EARTHWORK

At the time of report preparation, grading plans were not available. If cuts and fills exceed 4 feet of depth, we should be contacted for specific earthwork recommendations, especially stability of adjacent structures, shoring requirements, cut slopes, and construction dewatering. In any case, site grading should be carefully planned so that positive drainage away from all structures is achieved. Following earthwork recommendations should be followed for all aspects of the project.

Excavation: Materials encountered at this site may be excavated with conventional mechanical excavating equipment. Although our borings did not encounter “buried” foundation elements or other structures or debris, these materials may be encountered during excavation activities.

Debris materials such as brick, wood, concrete, and abandoned utility lines, if encountered, should be removed from structural areas when encountered in excavations and either wasted from the site or placed in landscaped areas.

Temporary excavations should comply with OSHA and other applicable federal, state, and local safety regulations. In our opinion, OSHA Type C soils will be encountered at this site during excavation. OSHA recommends maximum allowable unbraced temporary excavation slopes of 1.5:1(H:V) for Type C soils for excavations up to 15 feet deep. Permanent cut slopes are anticipated to be stable at slope ratios as steep as 2H:1V (horizontal to vertical) under dry conditions. New slopes should be revegetated as soon as possible after completion to minimize erosion.

Revised January 7, 2018 Page No: 11 of 15

We recommend a minimum of 10 feet of clearance between the top of excavation slopes and soil stockpiles or heavy equipment or adjacent structures (subject to approval of AGS). If braced excavations are to be used, they should be reviewed and designed by AGS. It should be noted that near-surface soils encountered at the site will be susceptible to some sloughing and excavations should be periodically monitored by AGS’s representative.

If excavation is performed under water table, or excavation is made steeper than OSHA recommendations, proper shoring should be provided. It is contractor’s responsibility to assure safety during excavation and earthwork operations.

Construction Dewatering: Due to the absence of high water table, construction dewatering may not be critical for this project. However, depending upon the season, we recommend developing a construction dewatering plan prior to the beginning of excavation. As a minimum, an interceptor drain outside the entire perimeter of proposed building may be considered with proper maintenance during construction. Sumps and pumps may also be required depending upon the construction season.

During construction in wet or cold weather, grade the site such that surface water can drain readily away from the building areas. Promptly pump out or otherwise remove any water that may accumulate in excavations or on subgrade surfaces, and allow these areas to dry before resuming construction. Berms, ditches and similar means may be used to prevent storm water from entering the work area and to convey any water off-site efficiently.

Fill Placement: Fill material should be placed under proper moisture control, in uniform horizontal layers (lifts) not exceeding 8 inches, before compacting to the required density and before successive layers are placed. If the contractor's equipment is not capable of properly moisture conditioning and compacting 8-inch lifts, then the lift thickness shall be reduced until satisfactory results are achieved.

Fill under the foundations should be granular, non-expansive and free from organics and non-soil materials. Imported structural fill should consist of sand or gravel material with a maximum particle size of 3 inches or less. In addition, this material shall have a liquid limit less than 30 and a plasticity index of 15 or less. Structural fill should also have a percent fine between 15 to 30 percent passing the No. 200 sieve. Structural fill should be moisture conditioned to within 2 percent of OMC and compacted to at least 95 percent of Standard Proctor (ASTM D698) maximum dry density. Compaction in the wall backfill areas should be 85% or greater.

Permanent fill slopes are anticipated to be stable at slope ratios as steep as 2H:1V (horizontal to vertical) under dry conditions. New slopes should be revegetated as soon as possible after completion to minimize erosion.

Revised January 7, 2018 Page No: 12 of 15

Cold Weather Construction: If earthwork is performed during the winter months when freezing is a factor, no grading fill, structural fill or other fill should be placed on frosted or frozen ground, nor should frozen material be placed as fill. Frozen ground should be allowed to thaw or be completely removed prior to placement of fill. A good practice is to cover the compacted fill with a “blanket” of loose fill to help prevent the compacted fill from freezing overnight. The “blanket” of loose fill should be removed the next morning prior to resuming fill placement.

During cold weather, foundations, concrete slabs-on-grade, or other concrete elements should not be constructed on frozen soil. Frozen soil should be completely removed from beneath the concrete elements, or thawed, scarified and re-compacted. The amount of time passing between excavation or subgrade preparation and placing concrete should be minimized during freezing conditions to prevent the prepared soils from freezing. Blankets, soil cover or heating as required may be utilized to prevent the subgrade from freezing.

CONCRETE & STEEL CONSTRUCTION

Concrete sidewalks and any other exterior concrete flatwork around the proposed structure may experience some differential movement and cracking. While it is not likely that the exterior flatworks can be economically protected from distress, we recommend following techniques to reduce the potential long-term movement:

• Scarify and re-compact at least 12 inches of subgrade material located immediately beneath structures.

• Avoid landscape irrigation and moisture holding plants adjacent to structures.

• Thicken or structurally reinforce the structures.

We recommend Class 2 sulfate resistance as per ACI 201 standards for all concrete in contact with the soil on this site. Calcium chloride should not be added. Concrete should not be placed on frost or frozen soil. Concrete must be protected from low temperatures and properly cured.

We anticipate corrosive potential for on-site soils.

Revised January 7, 2018 Page No: 13 of 15

PAVEMENT DESIGN & CONSTRUCTION

Based on the results of our subsurface exploration, we anticipate sandy soil subgrades for pavements, which is equivalent to soil classification A-2/A-3 in accordance with American Association of State Highway and Transportation Officials (AASHTO). All pavement subgrades should be surficially compacted with a vibratory steel wheel drum roller, then proof-rolled and approved by a registered geotechnical engineer from our office prior to the placement of base rock or pavement materials.

We used the Unified Facilities Criteria (UFC) Pavement Design Method (UFC 3-250-01) dated 14 November 2016, including the PCASE Computer Program, for the design of pavements for a design life of 25 years. Results of our design are summarized below.

Pavement Area Full-depth

AC

(Inches)

AC + ABC

(Inches)

PCC

Parking 5.0 3.0 AC + 6.0 ABC 5.5 Driveways, Fire Lanes, and Heavy Traffic / Loading Areas

6.5 4.5 AC + 6.0 ABC 6.0

AC: Asphaltic Concrete; ABC: Aggregate Base Course; PCC: Portland Cement Concrete

If specific pavement loading is planned or if some of our recommendations given here cannot be followed, we should be contacted immediately.

We recommend the use of PCC (instead of AC) in areas of loading/unloading, concentrated loading, and turning movements by heavy vehicles. These areas typically include delivery zones, entrances and trash collection/dumpster locations. All PCC pavement should have adequate construction joints, including longitudinal and transverse joints. All joints should be formed during construction or sawed into freshly setting concrete prior to uncontrolled cracking. All formed joints should be properly sealed. Proper curing procedures should be used to protect PCC pavements from moisture loss, freezing, rapid temperature change, and mechanical injury. Traffic should not be allowed during the first week after pavement construction.

Pavement areas should be properly graded and adequate drainage provided in order to assure quick removal of water or surface run-off from pavement areas. Ponding of water should not be allowed. All joints and curb areas should be properly sealed to minimize water infiltration. Proper and routine maintenance including annual crack repair and 5-6 year overlays should be performed to assure long-term performance of AC pavements. Similarly, regular maintenance and sealing of concrete joints should be done for PCC pavements. Deicing salts should not be used during the first year after pavement construction.

Revised January 7, 2018 Page No: 14 of 15

All pavement materials and placement methods should conform to the requirements given in the most current Colorado Department of Transportation’s (CDOT) “Standard Specifications for Road and Bridge Construction.” In addition, all applicable specifications and requirements of the local City should be followed. Pavement materials should be submitted for our review and tested for conformance with CDOT and local City specifications.

LIMITATIONS

Recommendations contained in this report are based on our field observations and subsurface explorations, limited laboratory evaluation, and our present knowledge of the proposed construction. It is possible that soil conditions could vary between or beyond the points explored.

If soil conditions are encountered during construction that differ from those described herein, we should be notified so that we can review and make any supplemental recommendations necessary. If the scope of the proposed construction, including the proposed loads or structural locations, changes from that described in this report, our recommendations should also be reviewed and revised by AGS.

Our Scope of Work for this project did not include any flood hazard evaluation, civil engineering evaluation of any kind, research, testing, or assessment relative to past or present contamination of the site by any source. If such contamination were present, it is very likely that the exploration and testing conducted for this report would not reveal its existence. If the Owner is concerned about the potential for such contamination, additional studies should be undertaken. We are available to discuss the scope of such studies with you. No tests were performed to detect the existence of mold or other environmental hazards as it was beyond Scope of Work.

Local regulations regarding land or facility use, on and off-site conditions, or other factors may change over time, and additional work may be required with the passage of time. Based on the intended use of the report within one year from the date of report preparation, AGS may recommend additional work and report updates. Non-compliance with any of these requirements by the client or anyone else will release AGS from any liability resulting from the use of this report by any unauthorized party. Client agrees to defend, indemnify, and hold harmless AGS from any claim or liability associated with such unauthorized use or non-compliance.

In this report, we have presented judgments based partly on our understanding of the proposed construction and partly on the data we have obtained. This report meets professional standards expected for reports of this type in this area. Our company is not responsible for the conclusions, opinions or recommendations made by others based on the data we have presented. Refer to American Society of Foundation Engineers (ASFE) general conditions included in an appendix.

This report has been prepared exclusively for the client, its’ engineers and subcontractors for the purpose of design and construction of the proposed structure. No other engineer, consultant, or

Revised January 7, 2018 Page No: 15 of 15 contractor shall be entitled to rely on information, conclusions or recommendations presented in this document without the prior written approval of AGS.

We appreciate the opportunity to be of service to you on this project. If we can provide additional assistance or observation and testing services during design and construction phases, please call us at 1 888 276 4027.

Sincerely, Sam Adettiwar, MS, PE, GE, P.Eng, M.ASCE Senior Engineer

Attachments

FIGURES

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REFERENCE:

NOTE:

SITE IS NOT UNDERLAIN DIRECTLY BY EXPANSIVE SOILS

OR BEDROCK FORMATION .

SITE IS NOT UNDERLAIN BY COLLAPSIBLE SOILS.

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FIGURE 4: EXPANSIVE SOILS MAP

PROPOSED BOREHOLE LOCATIONS - TO BE DRILLING ON 12/7/2017

NOTES:

4 .

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A. ADDITIONAL REINFORCEMENT, #4 CONTINUOUS BAR,

BOTTOM OF FOOTING. .,_ ·

B. ADDITIONAL REINFORCEMENT, #4 AT 48" C/C, TOP OF

FOOTING.

C. REINFORCEMENT AS PER STRUCTURAL ENGINEER'S

DESIGN. AS A MINIMUM, USE #4 AT 48" C/C.

.i . . .

4 ..

,4·:

----- CMU OR CONCRETE RETAINING WALL

REINFORCEMENT TO BE DONE BY

PROJECT STRUCTURAL ENGINEER BASED

ON GEOTECHNICAL RECOMMENDATIONS.

. : 4".

• : .it, •

CONCRETE FOOTING TO BE

DIMENSIONED BY PROJECT

STRUCTURAL ENGINEER BASED ON

GEOTECHNICAL RECOMMENDATIONS .

B · .. · .... "' -· . ., · .

. ... · . 4.,4_: ·.

ADDITIONAL FOOTING REINFORCEMENT DETAIL

AMERICAN GEOSERVICES

""" .a n1crican�cosc1·vicc�.com

Ph.111111-271i--1027. F\.!!77-471-IIJ(,'.>

FIGURE 7: TYPICAL DETAILS

SILICON SEAL OR HIGH UALITY

FLEXIBLE ADHESIVE EQUIVALENT,

4" ABOVE GROUND;

MAINTAIN LEAK-FREE

4 ,. .

. . �a -+---r-

LEAK-FREE AND ADEQUATE

CAPACITY DOWNSPOUTS

MINIMUM 3" THICK

DECORATIVE GRAVEL,

ROCK OR BARK LA YER

AT LEAST 4 FT LONG

20 MIL THICK POLY

SHEET LINER AT LEAST

4FT LONG; EXTEND 4"

ABOVE GROUND & 36"

BELOW GROUND

EXTEND DOWNSPOUT AS

MUCH AS POSSIBLE,

AWAY FROM BUILDING

WALL WITHOUT CAUSING

ADVERSE IMPACT

ON ADJACENT

PROPERTIES; DISCHARGE

ONTO SPLASH BLOCKS.

10H:1V FINISHED GRADE

FOR POSITIVE DRAINAGE

AWAY FROM BUILDING.

6"MIN 1--

l OFFSET FOR ANY

SPRINKLER

HEADS; PART CIRCLE

SPRAYING

AWAY FROM BUILDING

DOWNSPOUT & MOISTURE BARRIER DETAIL

COMPACTED EARTH BACKFILUSOIL CAP ----

(DO NOT USE IF STEM WALL IS

DESIGNED AS A RETAINING WALL. IN

CASE OF RETAINING WALL, USE

FREE-DRAINING CRUSHED ROCK FILL TO

AVOID HYSROSTATIC PRESSURE.

FOUNDATION/STEM WALL ---

POLYETHYLENE FILM GLUED TO

FOUNDATION WALL AND EXTENDED

BELOW THE DRAIN AS SHOWN

(ESTIMATED TO

BE 0.0' FOR THE SITE)

_l vSUBGRADE, IN-SITU SOI�

(SEE NOTE C)

SLOPE TO DRAIN AWAY

FROM STRUCTURE, 10H:1V

(SEE DOWNSPOUT DETAIL)

MIRAFI 140 N FILTER

FABRIC OR EQUIVALENT

x,,..,...,._ ______ EXCAVATED TRENCH, FREE-DRAINING

CLEAN CRUSHED

ROCK/GRAVEL

NEAR VERTICAL TO

0.5H:1V

PERIMETER OR FOUNDATION DRAIN DETAIL

NOTES: A. 4-INCH DIAMETER PERFORATED PIPE PLACED AT ELEVATION BELOW OR ABOVE FOOTING SUBGRADE EMBEDDED IN FREE-DRAINING GRAVEL OR CRUSHED ROCK ENVELOPE WITH MINIMUM 0.5% GRADE TO SUMP PIT OR DISCHARGED TO A SUITABLE RECEPTACLE SUCH THAT ON-SITE AS WELL AS OFF-SITE STABILITY IS NOT ADVERSELY IMPACTED. B. DEPTH BASED ON OPEN HOLE INSPECTION, FOR SHALLOW FOUNDATION OPTION. C. ALL FOUNDATION OR OVER-EXCAVATED SUBGRADES

MUST BE INSPECTED AND APPROVED BY A GEOTECHNICAL ENGINEER.

AMERICAN GEOSERVICES

,, \\'\\ .amcrican�cosen'icc�.t.·om l'h.l!XX-276--11127. I· ,.1!77--171-0:1(,9

FIGURE 8:TYPICAL DRAINAGE DETAIL

spiri Line spiri Oval

APPENDIX

TOPSOIL: 3.0" thick, sand and organics

SAND, fine to medium grained, dark brown to brown, trace gravel, trace silt, loose to medium dense, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

6-4-6

8-10-11

SP

SP

NP

NP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B1

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 14 feet

10-8-13 60 13.5 NP

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

NP

9-12-15 85 12.0 NPNP

spiri Line spiri Line spiri Line spiri Line

Line to brown, trace gravel, trace silt, loose to medium dense, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

5-5-5

7-11-10

SP

SP

NP

NP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B2

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 15 feet

10-10-11 70 7 NP

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

NP

11-12-11 90 13.0 spiri Line spiri Line spiri Line spiri Line

TOPSOIL: 2.5" thick, sand and organics to brown, trace gravel, trace silt, loose to medium dense, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

5-7-6

4-8-6

SP

SP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B3

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 15 feet

9-10-9 60

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

spiri Line spiri Line to brown, trace gravel, trace silt, loose to medium dense, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

5-7-6

6-8-10

SP

SP

NP

NP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B4

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 16 feet

10-10-9 70

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

8-11-15 85 spiri Line spiri Line spiri Line spiri Line to brown, trace gravel, loose, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

5-5-5

7-11-10

SP

SP

NP

NP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B5

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 15 feet

10-10-11 70 7 NP

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

NP

11-12-11 90 13.0 spiri Line spiri Line spiri Line spiri Line

TOPSOIL: 2.0" thick, sand and organics to brown, trace gravel, trace silt, loose to medium dense, moist

5-5-6

7-8-6

SP

SP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B6

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 15 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

11-9-10 50

End of Borehole at 15 feet.

Groundwater was not encountered during or at the completion of drilling.

At completion, borehole was backfilled with soil cuttings.

spiri Line spiri Line to brown, trace gravel, trace silt, loose to medium dense, moist

End of Borehole at 25 feet. Groundwater was not encountered during or at the completion of drilling.

5-5-5

7-11-10

SP

SP

NP

NP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B7

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 25 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Moist to very moist below 15 feet

10-10-11 70 7 NP

SAND to CLAYEY SAND, fine to medium grained, brown, trace gravel, medium dense, moist to very moist

At completion, borehole was backfilled with soil cuttings. 25

SP/

SC

NP

11-12-11 90 13.0 spiri Line spiri Line spiri Line spiri Line to brown, trace gravel, trace silt, loose to medium dense, moist

4-5-7

8-8-8

SP

SP

PROPOSED MILITARY WORKING DOG KENNEL FACILITY

B8

PETERSON AIRFORCE BASE, COLO. SPRINGS, CO

Project Number 0401-CS17 Geologist/Engineer SMA Date Drilled 12-11-2017 Borehole Diameter 4 OD Inches

Drill Rig: CME55 Solid Stem Auger, 4" Diameter Ground Elevation

M oi st ur e

See Figures Total Depth of Borehole 15 Feet Depth to Water Table Not encountered

G ra ph ic

L og

Description / Lithology

D ep th (f ee t)

Sa m pl e

C om pl et io n

D D

(p cf

R ec ov er y

Sw el l (

SP

T

B lo w C ou nt

LL

P

L

SAND, medium to coarse grained, brown, trace to some gravel, trace silt, loose to medium dense, moist

Very moist at 13-15 feet

End of Borehole at 15 feet.

Groundwater was not encountered during or at the completion of drilling.

At completion, borehole was backfilled with soil cuttings.

spiri Line

UNIFIED SOIL CLASSIFICATION AND SYMBOL CHART

COARSE-GRAINED SOILS

(more than 50% of material is larger than No. 200 sieve size.)

GRAVELS

More than 50% of coarse fraction larger than No. 4 sieve size

SANDS

50% or more of coarse fraction smaller than No. 4 sieve size

Clean Gravels (Less than 5% fines)

GW

GP

Well-graded gravels, gravel-sand mixtures, little or no fines

Poorly-graded gravels, gravel-sand mixtures, little or no fines

Gravels with fines (More than 12% fines)

GM

GC

Silty gravels, gravel-sand-silt mixtures

Clayey gravels, gravel-sand-clay mixtures

Clean Sands (Less than 5% fines)

SW

SP

Well-graded sands, gravelly sands, little or no fines

Poorly graded sands, gravelly sands, little or no fines

Sands with fines More than 12% fines

SM Silty sands, sand-silt mixtures

SC Clayey sands, sand-clay mixtures

FINE-GRAINED SOILS

(50% or more of material is smaller than No. 200 sieve size.)

SILTS

AND

CLAYS

Liquid limit less than

50%

SILTS

AND

CLAYS

Liquid limit 50% or greater

HIGHLY

ORGANIC

SOILS

ML

CL

OL

MH

CH

OH

PT

Inorganic silts and very fine sands, rock flour, silty of clayey fine sands or clayey silts with slight plasticity Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays

Organic silts and organic silty clays of low plasticity

Inorganic silts, micaceous or diatomaceous fine sandy or silty soils, elastic silts

Inorganic clays of high plasticity, fat clays

Organic clays of medium to high plasticity, organic silts

Peat and other highly organic soils

GW

GP

GM

GC

SW

SP

SM

SC

LABORATORY CLASSIFICATION CRITERIA

cu D 50 D 30 = - -greater than 4; Cc =…