240607 BSFD No. 3 - Geotech Report.pdf
PDF 8 MB Posted
- Attached to
- Material Testing and 3rd Party Inspections
- Solicitation number
- RFP_F-BSFD-0000000002
- Issued by
- Gallatin County, Montana
About this file
The document is a geotechnical engineering investigation report prepared by CTL|Thompson, Inc. for CH SP Acquisition, LLC for the South Fork Road Fire Station project located in Madison County, Montana. The report details the subsurface conditions, site geology, and geotechnical recommendations for the proposed two-story fire station within the Spanish Peaks development. The investigation involved excavating two exploratory pits and drilling three exploratory borings to analyze soil and bedrock characteristics, with the site located near the base of a hill sloping southwest at grades of 10 to 15 percent.
The report provides comprehensive recommendations for site preparation, including subexcavation, structural fill placement, foundation construction, pavement design, and drainage management. Key findings include the presence of claystone bedrock near the ground surface, potential for soil expansion when wetted, and recommendations for mitigating potential ground movement and settlement. The site's soils are classified as highly plastic clay with a low R-value, requiring specific construction techniques such as subexcavation to a depth of 3 feet, use of granular structural fill, and careful compaction methods. The investigation suggests using either hot-mix asphalt or Portland cement concrete for pavements, with detailed specifications for material composition, placement, and compaction.
View the file
Other files
On GovTribe
Work with this file
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
CTL|Thompson, Inc.
Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado
Cheyenne, Wyoming and Bozeman, Montana
SOUTH FORK ROAD FIRE STATION
MADISON COUNTY, MONTANA
Prepared for:
CH SP ACQUISITION, LLC
P.O. Box 160040
Big Sky, MT 59716
Attention:
Jon Olsen, P.E.
Project No. MT01140.000-125
June 7, 2024
GEOTECHNICAL ENGINEERING INVESTIGATION
https://ctlthompson.com/ https://ctlthompson.com/denver https://www.ctlthompson.com/fortcollins https://www.ctlthompson.com/coloradosprings https://www.ctlthompson.com/glenwoodsprings https://www.ctlthompson.com/pueblo https://www.ctlthompson.com/summitcounty https://www.ctlthompson.com/cheyenne https://www.ctlthompson.com/bozeman
Table of Contents
CH SP ACQUISITION, LLC Page i of ii
SOUTH FORK ROAD FIRE STATION
CTL|T PROJECT NO. MT01140.000-125
SCOPE
SITE CONDITIONS
PROPOSED CONSTRUCTION
SITE GEOLOGY
Seismicity
SUBSURFACE CONDITIONS
EARTHWORK
Excavation
Subexcavation and Structural Fill
Site Grading Fill
Foundation Wall Backfill
Utility Trench Backfill
Pavement Subgrade
Permanent Slope Construction
BUILDING FOUNDATION
SLAB-ON-GRADE CONSTRUCTION
BUILDING FOUNDATION WALLS
SITE EARTH RETAINING WALLS
SURFACE DRAINAGE
SUBSURFACE DRAINAGE
CONCRETE
PAVEMENTS
CONSTRUCTION OBSERVATIONS
GEOTECHNICAL RISK
LIMITATIONS
FIGURE 1 – VICINITY MAP
FIGURE 2 – AERIAL PHOTOGRAPH
FIGURE 3 – PROPOSED DEVELOPMENT
FIGURE 4 – SUMMARY LOGS OF EXPLORATORY PITS
FIGURE 5 – SUMMARY LOGS OF EXPLORATORY BORINGS
FIGURE 6 AND 7 – SWELL-CONSOLIDATION TEST RESULTS
FIGURE 8 – GRADATION TEST RESULTS
Table of Contents, Continued
CH SP ACQUISITION, LLC Page ii of ii
SOUTH FORK ROAD FIRE STATION
CTL|T PROJECT NO. MT01140.000-125
TABLE I – SUMMARY OF LABORATORY TESTING
APPENDIX A – EXPLORATORY PIT PHOTOGRAPHS
APPENDIX B – SOIL SAMPLE PHOTOGRAPHS
APPENDIX C – PAVEMENT MATERIALS AND CONSTRUCTION RECOMMENDATIONS
CH SP ACQUISITION, LLC 1 of 18
CTL|T PROJECT NO. MT01140.000-125
SCOPE
CTL|Thompson, Inc. (CTL|T) has completed a geotechnical engineering investigation for the South Fork Road Fire Station that is proposed within the Spanish Peaks development in
Gallatin County, Montana. We conducted this investigation to evaluate subsurface conditions at the site and provide geotechnical engineering recommendations for design and construction of the building. Our geotechnical engineering recommendations were developed with data from our field exploration, laboratory testing, engineering analysis, and our experience with similar conditions. The recommendations in this report are based on the construction as currently planned. Revisions to the planned construction could affect our recommendations. CTL|T should be contacted to participate in design-team meetings so we can provide geotech-nical/geo-structural engineering input.
SITE CONDITIONS
The South Fork Road Fire Station is proposed east of the intersection of South Fork
Road and Inspiration Point Road within the Spanish Peaks Development. A vicinity map with the location of the site is included as Figure 1. The site is bounded by South Fork Road to the south and Inspiration Point Road to the west and north. Vacant land is east of the site. An aerial pho-tograph (dated June 2014) of the site is shown on Figure 2. The site is near the base of a hill that slopes down to the southwest at grades of about 10 to 15 percent. The site has sparse co-niferous trees and ground cover consists of native grass and shrubs. A vehicle pullout is present on the west side of the site.
PROPOSED CONSTRUCTION
CTL|T was provided with schematic design plans for the fire station by OZ Architecture
(OZ) dated March 29, 2024. A plan view of the proposed construction is shown on Figure 3. The fire station will be a two-story building that is partially below-grade on the uphill (northeast) side.
The building will have three apparatus bays for fire trucks, vehicles, and equipment storage. The building will include offices, restrooms, and living quarters. An exterior staircase is planned at the northwest corner of the building. The building will be surrounded by paved parking and ac-cess drives to the south, east and west. Access to the site will be from South Fork Road and In-spiration Point Road.
CH SP ACQUISITION, LLC 2 of 18
CTL|T PROJECT NO. MT01140.000-125
The northeast side of the building will be below-grade. The proposed finished floor ele-vation is 6467 feet, which is about 22 feet below existing grades at the northeast corner. We an-ticipate excavation depth of about 30 feet will be needed at the northeast corner to reach the bottom of proposed subexcavation elevations to facilitate the currently planned construction. We anticipate the contractor intends to lay the temporary excavation back at safe slopes per OSHA standards. It appears fill depths up to about 10 feet are planned at the southwest side of the building. Permanent slopes are planned at inclinations of 2:1 (horizontal:vertical).
Site plans indicate permanent retaining walls are planned east of the building, above the parking area. We were not provided with retaining wall details. It appears a three-tier retaining wall is contemplated, with a total maximum height of about 13 feet. Existing slopes with grades of about 10 to 15 percent are above the proposed retained slope.
SITE GEOLOGY
As part of our geotechnical investigation, we reviewed geologic mapping by the Montana
Bureau of Mines and Geology (MBMG) titled, “Geologic Map of the Sphinx Mountain quadrangle and adjacent parts of the Cameron, Cliff Lake, and Hebgen Dam quadrangles, Montana” by
Russell G. Tysdal (dated 1990). The mapping indicates the site is underlain by bedrock of the
Mowry Shale Formation that is near the ground surface.
The Mowry Shale Formation is described as slope-forming, dark-gray mudstone and silty mudstone, and a few interbeds of siltstone, sandstone, bentonite, coal and coaly shale in the upper part. The lower part of the formation is predominantly gray green, yellow, and brown, or-ange mudstone, bentonitic mudstone, porcellanite; welded tuff and siltstone. The claystone ob-served in our exploratory borings appears to be consistent with the described mudstone in the upper part of the formation. The natural overburden soils encountered in our borings appear to be directly derived from weathering of the underlying bedrock.
Geologic constraints mapping by Treadwell & Rollo (T&R) shows the proposed fire sta-tion site is about 200 feet southeast of the southeastern extent of a mapped landslide desig-nated as LS-13. We do not believe the subject site is at risk of significant lateral ground move-ment.
CH SP ACQUISITION, LLC 3 of 18
CTL|T PROJECT NO. MT01140.000-125
Seismicity
Based on criteria set forth in ASCE/SEI7-16, we estimate a Seismic Site Class C for the proposed fire station site. Assuming a Risk Category II for the structure, we estimate a peak ground acceleration (PGA) of 0.369, a maximum earthquake spectral response acceleration for the short period (SS) of 0.852, and a maximum spectral response acceleration for the 1-second period (S1) of 0.272. A geophysical consultant can utilize field testing methods, such as multi-channel analysis of surface waves (MASW), to measure the shear wave velocity in the upper
100 feet of the subsurface profile. This would provide data to determine whether a Site Class B can be used for structural design.
SUBSURFACE CONDITIONS
We investigated subsurface conditions at the site by observing excavation of two explor-atory pits (TP-1 and TP-2) in proposed pavement areas and drilling three exploratory borings
(TH-1, TH-2, and TH-3) near the proposed structure footprint. Approximate locations of the ex-ploratory pits and borings are shown on Figures 2 and 3. The pits were excavated with a track-hoe on March 7, 2024. The borings were drilled on March 11 and 12, 2024 with a track-mounted, CME-45 drill rig and 6-inch diameter, hollow-stem auger.
Exploratory excavation and drilling operations were directed by our engineer, who logged subsurface conditions encountered and obtained representative samples of the soils and bedrock. Summary logs of subsurface conditions encountered in our exploratory pits and bor-ings are included as Figures 4 and 5, respectively.
Subsurface conditions encountered in our pits consisted of about 12 inches of topsoil or
18 inches of sandy clay fill underlain by slightly sandy clay with gravel over weathered and com-paratively unweathered claystone bedrock to the maximum explored depth of 10 feet. The clay was highly plastic, with liquid limits of 68 and 87 and plasticity indices of 52 and 63 in two sam-ples. We encountered weathered claystone at a depth of about 4.5 feet and relatively unweath-ered claystone at a depth of 9.5 feet in TP-2. We did not encounter water in the pits at the time of excavation. Photographs of subsurface conditions encountered in our exploratory pits are in
Appendix A. The pits were backfilled immediately after excavation operations were completed.
CH SP ACQUISITION, LLC 4 of 18
CTL|T PROJECT NO. MT01140.000-125
Bulk samples were obtained from the excavated soils. Photographs of soil samples from our pits are included in Appendix B.
Subsurface conditions encountered in our exploratory borings consisted of about 6 to 12 inches of topsoil underlain by slightly sandy clay over weathered to comparatively unweathered claystone bedrock to the maximum explored depth of 27.5 feet. We encountered practical auger refusal in TH-3 at a depth of 10 feet. We did not encounter water in our borings during drilling.
Samples were obtained from our borings with a 2.5-inch outer diameter (OD) California-barrel sampler and a 2.0-inch outer diameter (OD) Split-spoon sampler, as well as from the auger cut-tings. The borings were backfilled immediately after exploratory drilling operations were com-pleted.
Samples of the soils obtained from our exploratory pits and borings were returned to our laboratory for pertinent testing. Laboratory testing included swell-consolidation, particle grada-tion analysis (full gradation and passing No. 200 sieve), Atterberg limits, and water-soluble sul-fates. Three claystone samples swelled 0.6 to 1.6 percent when wetted under an appleied pres-sure of 1,000 psf.. The clay and claystone were lean to highly plastic, with liquid limits of 34 to
55 and plasticity indices of 18 to 30 in three samples. Swell test results are shown on Figures 6 and 7. GThe gradation test result is shown on Figure 8. Laboratory testing is summarized on
Table I.
EARTHWORK
Excavation
We anticipate maximum excavation depths for the fire station foundation will be on the order of 30 feet. We expect excavations at the site can be accomplished using conventional, heavy-duty excavation equipment. The foundation excavation at the north side of the building can likely be constructed without excavation retention, provided the temporary excavation face is no steeper than 1:1 (horizontal:vertical).
Sides of excavations must be sloped or braced to meet local, state, and federal safety regulations, including the current OSHA Excavation and Trench Safety Standards. We believe the soils at this site will likely classify as Type B soils based on OSHA standards, which typically
CH SP ACQUISITION, LLC 5 of 18
CTL|T PROJECT NO. MT01140.000-125
require maximum side slope inclinations of 1:1 for temporary excavations deeper than 4 feet in dry conditions. Groundwater seepage can cause slumps and sloughing and the need for flatter excavation slopes. The contractor’s “competent person” is required to review excavation condi-tions and refer to OSHA Standards when worker exposure is anticipated.
We do not anticipate excavations for the planned construction at the site will penetrate a free groundwater table. Our experience in similar geology and topography in the area indicates the upper soils may become saturated during snowmelt in spring and early summer. Significant water flow into excavations could occur during this period. We recommend against excavation during periods of snowmelt. Water from seepage, precipitation, and snowmelt can likely be miti-gated by sloping excavations to gravity discharges, or to temporary sumps, where water can be removed by pumping.
Subexcavation and Structural Fill
Our subsurface information indicates the natural clay soils and claystone bedrock have potential for expansion when wetted under building loads. This presents risk of damaging move-ments below foundations, floor slabs, pavements, and other improvements. We judge that foot-ings are suitable for the building, provided the soils are subexcavated to a depth of at least 3 feet below bottom of foundation and floor slab elevations. Footing and floor slab elevations can be re-attained with properly compacted, granular, structural fill. The subexcavated areas should extend laterally at least 1 foot beyond the perimeter of the building footprint. CTL|T should be called to observe conditions in the subexcavated areas, prior to placement of structural fill. If soft or loose soils are present at excavation bottoms, they will need to be stabilized, prior to fill placement.
We recommend structural fill consist of an imported pit run with a maximum rock size of
4 inches and 10 to 30 percent silt and clay size material. Pit run material from the Morgan Pit and Moonlight Pit have been successfully used on many projects within Spanish Peaks. Poten-tial import material should be submitted to our office for approval prior to importing to the site.
Topsoil and organics should be stripped from areas to receive fill. Structural fill should be placed in loose lifts of 8 inches thick or less, moisture conditioned to within 2 percent of optimum
CH SP ACQUISITION, LLC 6 of 18
CTL|T PROJECT NO. MT01140.000-125
moisture content, and compacted to at least 98 percent of standard Proctor (ASTM D 698) max-imum dry density. Moisture content and density of structural fill should be checked by a repre-sentative of our firm during placement. Fill placement and compaction should not be conducted when the fill material or subgrades are frozen. Observation of the compaction procedure is nec-essary.
Site Grading Fill
Topsoil and organics should be stripped from areas to receive fill. The on-site soils can be used for site grading fill in landscape areas that will not support structures. Site grading fill should be placed in loose lifts of 8 inches or less, moisture conditioned to within 2 percent of op-timum moisture content, and compacted to at least 95 percent of standard Proctor (ASTM D
698) maximum dry density. Moisture content and density of site grading fill should be checked by a representative of our firm during placement.
Foundation Wall Backfill
Proper placement and compaction of foundation backfill is important to reduce infiltration of surface water and settlement of backfill. However, excessive compaction of the backfill soils adjacent to concrete walls may result in cracking of the wall. The potential for cracking will vary depending on many factors, including the degree of compaction achieved, the weight and type of compaction equipment utilized, the structural design of the wall, the strength of concrete at the time of backfill compaction, and the presence of temporary or permanent bracing.
We expect the soils excavated at the site can be used as backfill material, provided they are free of rocks larger than 4 inches in diameter, organics, and debris. Backfill should be placed in loose lifts of approximately 10 inches thick or less, moisture-conditioned to within 2 percent of optimum moisture content, and compacted to at least 95 percent of standard Proctor
(ASTM D 698) maximum dry density. Moisture content and density of the backfill should be checked by CTL|T during placement. Observation of the compaction procedure is necessary.
CH SP ACQUISITION, LLC 7 of 18
CTL|T PROJECT NO. MT01140.000-125
Utility Trench Backfill
We expect underground utilities may be constructed beneath pavements and flatwork providing access to the building. Compaction of utility trench backfill will have a significant effect on the life and serviceability of overlying pavements and exterior flatwork. Improper compaction of trench backfill can cause excessive settlement of backfill soils, leading to potential severe pavement deformity. The on-site soils free of rocks larger than 4 inches in diameter, organics, and debris can generally be used as utility trench backfill.
Trench backfill soils should be placed in loose lifts of 10 inches thick or less, moisture conditioned to within 2 percent of optimum moisture content and compacted to at least 95 per-cent of standard Proctor (ASMT D 698) maximum dry density. Special care is needed for backfill adjacent to manholes and vertical riser pipes. Our representative should test moisture content and density of the backfill during placement. Observation of the compaction procedure is neces-sary.
Pavement Subgrade
To enhance performance of pavements, we recommend subexcavation of the subgrade soils below pavement sections to a depth of at least 18 inches. The excavated soils free of rocks larger than 4 inches in diameter, organics, and debris can be reused as fill in subexca-vated pavement areas. Fill below pavements should be placed in loose lifts of 8 inches thick-ness or less, moisture-conditioned to within 2 percent of optimum moisture-content, and com-pacted to at least 95 percent of standard Proctor (ASTM D 698) maximum dry density. Moisture content and density of structural fill should be checked by a representative of our firm during placement. Observation of the compaction procedure is necessary.
After the subgrade has been compacted and tested, these areas should be proof-rolled to check for soft or deflecting areas. We recommend proof-rolling with a heavy, pneumatic-tired vehicle, such as a loaded dump truck or water truck. The proof-roll should be performed while moisture contents of the subgrade are still within recommended limits. Our representative should be called to observe proof-rolling. Drying of the subgrade prior to proof-roll or paving should be avoided. Areas of soft subgrade should be stabilized. We can provide geotechnical engineering input if areas require stabilization.
CH SP ACQUISITION, LLC 8 of 18
Permanent Slope Construction
Permanent slopes at an inclination of 2:1 or less steep should be stable provided they are constructed properly, and erosion control measured are designed, constructed, and main-tained during and after construction.
Topsoil and organics should be stripped from areas to receive fill. Where fill will be placed on slopes exceeding 20 percent (5:1), it should be placed on benches at 3- to 5-foot height intervals to expose firm soils. Fill slopes should be over-built and cut back to desired grade. The fill material for permanent slopes should be in accordance with recommendations in
Site Grading Fill.
Erosion protection should be designed, constructed, and maintained during and after construction. The contractor should provide and maintain positive site drainage during earth-work operations to maintain integrity of the surface soils. Cut and fill slopes should receive tem-porary matting, such as RollMaxTM EroNet SC150 or similar. Slope matting should be installed according to the manufacturer’s specifications. Many erosion control measures are available that can assist re-vegetation in the alpine environment. We recommend installation of erosion control and slope vegetation as soon as earthwork operations are completed.
BUILDING FOUNDATION
The natural soils and claystone bedrock at this site have potential for expansion when wetted under building loads. We judge a footing foundation is appropriate for the fire station building, provided recommended measures are implemented to mitigate potential for heave-re-lated damage. To reduce potential for damaging movements due to expansive soils and bed-rock, we recommend subexcavation to a depth of 3 feet below foundations and floor slabs. The subexcavated soils should be replaced with properly compacted, granular, structural fill as de-scribed in the Subexcavation and Structural Fill section.
Recommended design and construction criteria for footings are below. These criteria were developed based on our analysis of field and laboratory data as well as our engineering experience.
CH SP ACQUISITION, LLC 9 of 18
CTL|T PROJECT NO. MT01140.000-125
1. Footings should be supported on properly-compacted, granular, structural fill that is at least 3 feet thick as described in Subexcavation and Structural Fill.
2. Footings placed on properly-compacted, structural fill can be designed for a max-imum allowable bearing pressure of 3,000 psf.
3. A friction factor of 0.45 can be used to calculate resistance to sliding between concrete footings and structural fill.
4. Continuous wall footings for the building should have a minimum width of at least
16 inches. Footing pads for isolated columns should have minimum dimensions of 24 inches by 24 inches. Larger sizes may be required based on structural loads.
5. Footings and foundation walls should be well-reinforced. We recommend rein-forcement sufficient to span an unsupported distance of at least 10 feet.
6. Soils under exterior footings should be protected from freezing. We recommend the bottom of footings and pads be constructed at a depth of at least 42 inches below finished exterior grades. The Madison County building department should be consulted regarding required frost protection requirements.
SLAB-ON-GRADE CONSTRUCTION
We anticipate a slab-on-grade floor will be used for the structure. Slab-on-grade floors can be utilized in the building, provided the soils below the slabs are subexcavated to a depth of at least 3 feet below the bottom of slabs. The subexcavated soils should be replaced with properly-compacted structural fill in accordance with recommendations in the Subexcavation and Structural Fill section.
Based on our analysis of field and laboratory data, as well as our engineering experi-ence, we recommend the following precautions for slab-on-grade construction at this site.
1. Slabs should be separated from footings and column pads with slip joints which allow free vertical movement of the slabs.
2. Underslab plumbing should be pressure tested for leaks before the slabs are constructed. Plumbing and utilities which pass through slabs should be isolated from the slabs with sleeves and provided with flexible couplings to slab supported appliances.
3. Exterior slabs should be isolated from the building. These slabs should be well-reinforced to function as independent units.
CH SP ACQUISITION, LLC 10 of 18
CTL|T PROJECT NO. MT01140.000-125
4. Frequent control joints should be provided, in accordance with American Con-crete Institute (ACI) recommendations, to reduce problems associated with shrinkage and curling.
5. We recommend a 4-inch layer of clean gravel be placed beneath the slab to pro-vide a flat, uniform subgrade. This material should consist of minus 2-inch aggre-gate with at least 50% retained on the No. 4 sieve and less than 2% passing the No. 200 sieve.
6. The 2018 International Building Code (IBC R506) states that a 4-inch basecourse layer consisting of clean graded sand, gravel, crushed stone, or crushed blast furnace slag shall be placed beneath below slab-on-grade floors (unless the un-derlying soils are free-draining), along with a vapor retarder. The IBC may require a vapor retarder be placed between the base course or subgrade soils and the concrete slab-on-grade floors. The merits of installation of a vapor retarder below floor slabs depend on the sensitivity of floor coverings and building to moisture. A properly installed vapor retarder (10 mil minimum) is more beneficial below con-crete slab-on-grade floors where floor coverings will be sensitive to moisture.
BUILDING FOUNDATION WALLS
Foundation walls in the building that will retain earth should be designed for lateral earth pressures. Many factors affect the values of the design lateral earth pressure. These factors in-clude, but are not limited to, the type, compaction, slope, and drainage of the backfill, and the rigidity of the wall against rotation and deflection. Most building walls are designed to be rigid with the expectation of negligible deflection. In this circumstance, an “at-rest” lateral earth pres-sure should be used in design.
For backfill soils conforming to recommendations in the Foundation Wall Backfill sec-tion that are not saturated, we recommend design of the building walls at this site using 60 pcf for the on-site soils. These equivalent fluid densities do not include allowances for sloping back-fill, surcharges or hydrostatic pressures.
SITE EARTH RETAINING WALLS
Free-standing, tiered, earth retaining walls are proposed east of the fire station building.
We anticipate the tiered walls will have a total height of about 13 feet. In our opinion, several earth retention systems could be utilized at the site. These include mechanically stabilized earth
(MSE) structures, large-block retaining walls, and reinforced concrete retaining walls. Brief com-ments on each of these systems are below.
CH SP ACQUISITION, LLC 11 of 18
CTL|T PROJECT NO. MT01140.000-125
An MSE structure consists of alternating layers of compacted structural fill and geogrid reinforcement. Mobilized friction between the geogrid and structural fill results in a zone or rein-forced earth that essentially acts as a gravity retaining structure. The structure is faced with ma-sonry blocks that are connected to the geogrid reinforcement. The facing blocks prevent erosion and sloughing of the materials at the front of the reinforced earth zone and create an aestheti-cally pleasing wall. The bottom course of blocks is typically placed on a layer of densely-com-pacted, granular structural fill. A drainage layer is required behind the facing blocks. MSE struc-tures are relatively tolerant to ground movement.
Large-block earth retaining walls (e.g., Redi-rock) are constructed with pre-cast concrete blocks that are available in a variety of styles and colors. Walls with maximum heights of 9 feet can often be designed without geogrid reinforcement behind the wall. For this type of wall, the weight and interlocking nature of the blocks provides resistance to earth pressures in the re-tained slope. The bottom course of blocks is typically placed on a layer of densely-compacted, granular, structural fill. A drainage layer and some backfill soils are required behind the blocks.
Large-block retaining walls can accommodate a significant amount of ground movement.
A reinforced concrete retaining wall is a potential alternative to consider. These walls are constructed with two-sided forms, which must be stripped after the wall is cast. This could result in personnel in a trench-type situation between the wall and the excavation slope. OSHA guide-lines for trench safety apply. The footing foundation for the wall would likely need to be sup-ported on a 2-foot thickness of densely-compacted, granular structural fill. A drain system is re-quired behind reinforced concrete earth retaining walls to reduce potential hydrostatic pressure.
We recommend the equivalent fluid pressures in the table below be used for design of a rein-forced concrete site earth retaining wall.
CH SP ACQUISITION, LLC 12 of 18
CTL|T PROJECT NO. MT01140.000-125
LATERAL EARTH PRESSURES FOR SITE EARTH RETAINING WALLS
Imported Structural Fill Native Soils
Earth Pressure Condition Equivalent Fluid Pressure (Static Condition)
Equivalent Fluid Pressure (Static Condition)
Active 40 45 Passive 345 250
CTL|T can assist with design of any of these earth retention systems. We can provide additional recommendations as plans are further developed.
SURFACE DRAINAGE
Surface drainage is critical to the performance of foundations, floor slabs, and concrete flatwork. Site grading should be designed and constructed to rapidly convey surface water away from the structure. Proper surface drainage and irrigation practices can help control the amount of surface water that penetrates to foundation levels and contributes to settlement or heave of soils that support foundations and slabs-on-grade. Positive drainage away from the foundation and avoidance of irrigation near the foundation also help to avoid excessive wetting of backfill soils, which can lead to increased backfill settlement and possibly to higher lateral earth pres-sures, due to increased weight and reduced strength of the backfill. We recommend the follow-ing precautions.
1. The ground surface surrounding the exterior of the building should be sloped to drain away from the building in all directions. We recommend a minimum con-structed slope of at least 12 inches in the first 10 feet (10 percent) around the structure.
2. Backfill around the foundation and foundation walls should be moisture-condi-tioned and compacted according to the recommendations in the Foundation Wall Backfill section.
3. We recommend the building be provided with roof gutters and downspouts. The downspouts should discharge well beyond the limits of all backfill. Splash blocks and/or extensions should be provided at all downspouts so water discharges onto the ground beyond the backfill. We recommend against burial of downspout discharge pipes.
SUBSURFACE DRAINAGE
Our experience in similar geology and topography in the area indicates the upper soils become saturated during snowmelt in spring and early summer months. Frozen ground during
CH SP ACQUISITION, LLC 13 of 18
CTL|T PROJECT NO. MT01140.000-125
spring runoff can also create a perched condition. Additionally, water from precipitation, snow-melt, and irrigation frequently flows through relatively permeable backfill placed adjacent to a residence and collects on the surface of less permeable soils at the bottom of foundation exca-vations. These sources of water can cause wet or moist conditions in below-grade areas after construction. To reduce the likelihood water pressure will develop outside foundation walls, we recommend provision of a foundation wall drain around the perimeter of the structure.
The foundation wall drain should consist of 4-inch diameter, slotted PVC pipe encased in free-draining gravel. A prefabricated drainage composite should be placed adjacent to founda-tion wall exteriors. Care should be taken during backfill operations to prevent damage to drain-age composites. The drain should discharge via a positive gravity outlet. The gravity outlet should not be susceptible to clogging or freezing. We recommend installation of a clean-out along the drainpipe. CTL|T should be called to check that the drain is constructed properly, prior to backfilling.
CONCRETE
Concrete in contact with soil can be subject to sulfate attack. We measured a water-sol-uble sulfate concentration of 0.11 percent in one sample of the clay from the site. Pursuant to
ACI 318-19, the sulfate exposure class is Moderate or S1 as indicated on the table below.
SULFATE EXPOSURE CLASSES PER ACI 318-19
Exposure Classes Water-Soluble Sulfate (SO4) in
Soil A
Not Applicable S0 < 0.10 Moderate S1 0.10 to 0.20 Severe S2 0.20 to 2.00
Very Severe S3 > 2.00 A) Percent sulfate by mass in soil determined by ASTM C1580
For this level of sulfate concentration, ACI 318-19 Code Requirements indicates there are no special cement type requirements for sulfate resistance as indicated in the table below.
CH SP ACQUISITION, LLC 14 of 18
CTL|T PROJECT NO. MT01140.000-125
CONCRETE DESIGN REQUIREMENTS FOR SULFATE EXPOSURE PER ACI 318-19
Exposure Class
Maximum Water/
Cement Ratio
Minimum Compressive
Strength (psi)
Cementitious Material Types A Calcium
Chloride Ad-mixtures
ASTM
C150/
C150M
ASTM
C595/
C595M
ASTM
C1157/
C1157M
S0 N/A 2500 No Type Re-strictions
No Type Re-strictions
No Type
Restrictions No Restrictions
S1 0.50 4000 IIB Type with (MS) Designation MS No Restrictions
S2 0.45 4500 V B Type with (HS) Designation HS Not Permitted
S3 Option 1 0.45 4500 V + Pozzolan or Slag Cement C
Type with (HS) Designation plus Pozzolan or Slag
Cement C
HS + Pozzolan or Slag Cement C Not Permitted
S3 Option 2 0.4 5000 V D Type with (HS) Designation HS Not Permitted
A) Alternate combinations of cementitious materials shall be permitted when tested for sulfate resistance meet-ing the criteria in section 26.4.2.2(c).
B) Other available types of cement such as Type III or Type I are permitted in Exposure Classes S1 or S2 if the C3A contents are less than 8 or 5 percent, respectively.
C) The amount of the specific source of pozzolan or slag to be used shall not be less than the amount that has been determined by service record to improve sulfate resistance when used in concrete containing Type V cement. Alternatively, the amount of the specific source of the pozzolan or slab to be used shall not be less than the amount tested in accordance with ASTM C1012 and meeting the criteria in section 26.4.2.2(c) of
ACI 318.
D) If Type V cement is used as the sole cementitious material, the optional sulfate resistance requirement of
0.040 percent maximum expansion in ASTM C150 shall be specified.
Superficial damage may occur to the exposed surfaces of highly permeable concrete, even though sulfate levels are relatively low. To control this risk and to resist freeze-thaw deteri-oration, the water-to-cementitious materials ratio should not exceed 0.50 for concrete in contact with soils that are likely to stay moist due to surface drainage or high-water tables. Concrete should have a total air content of 6 percent ± 1.5 percent. We advocate damp-proofing of all foundation walls and grade beams in contact with the subsoils.
PAVEMENTS
Site grading fill below pavements should be in accordance with recommendations in the
Pavement Subgrade section. Based our laboratory testing, the on-site soils generally have an
AASHTO soil classification of A-7-6, which is considered relatively poor subgrade. We estimate an R-value of 5 for these soils.
CH SP ACQUISITION, LLC 15 of 18
CTL|T PROJECT NO. MT01140.000-125
Traffic loading numbers were not available at this writing. Much of the pavement will be subject to traffic from fire trucks. We estimated a 20-year Equivalent Single Axle Load (ESAL)
Value of 73,000 for the automobile parking areas and a 30-year ESAL of 164,000 for fire truck traffic areas. We should be provided with design traffic numbers when available so that we can review and/or refine our recommendations. Based on our calculations, we recommend the mini-mum pavement sections on the table below.
SUMMARY OF RECOMMENDED MINIMUM PAVEMENT ALTERNATIVES
Anticipated Traffic Type
Hot-Mix Asphalt
(HMA)
Hot-Mix Asphalt + Aggregate Base Course
(HMA + ABC)
Portland Cement Concrete
(PCC)
Automobile Parking Only 6” HMA 4” HMA + 6” ABC 6” PCC
Access Drives and Fire/Truck Lanes Not recommended Not recommended 7” PCC
Our experience indicates problems with asphalt pavements can occur in areas where heavy trucks drive and turn at low speeds. In areas of concentrated loading and turning move-ments by fire trucks and garbage trucks, we recommend Portland cement concrete pavement that is 7-inches or thicker.
The performance of a pavement system depends on the quality of the paving materials and construction, as well as the support characteristics of the subgrade. If the pavement system is constructed of inferior material, then the life and serviceability of the pavement will be sub-stantially reduced. We have included recommendations for pavement materials and construc-tion in the attached Appendix C.
A primary cause of early pavement deterioration is water infiltration into the pavement system. The addition of moisture usually results in softening of base course and subgrade and the eventual failure of the pavement. We recommend drainage be designed for rapid removal of surface runoff from pavement surfaces. Final grading should be carefully controlled so that de-sign cross-slope is maintained and low spots in the subgrade which could trap water are elimi-nated. Portland cement concrete drainage pans with subsurface drains should be considered in areas where water will be flowing across pavement surfaces.
CH SP ACQUISITION, LLC 16 of 18
CTL|T PROJECT NO. MT01140.000-125
The asphalt should consist of a mixture of aggregate, filler, and asphalt cement. The as-phalt should be a batched hot mix, approved by the engineer, and placed and compacted to a density of 92 to 96 percent of the maximum theoretical density. We recommend asphalt be placed in lifts with a minimum thickness of 1.5 inches and maximum thickness of 3 inches.
All concrete should be based on a mix design established by a qualified engineer. The design mix should consist of aggregate Portland cement, water, and additives which will meet the requirements contained in this section. The concrete should have a modulus of rupture of third point loading of 630 psi. Normally, concrete with a 28-day compressive strength of 4,000 psi will meet this value. The concrete should contain joints not greater than 15 feet on-centers.
Joints should be sawed or formed by pre-molded filler. The joints should be at least ¼ of the slab thickness. Expansion joints should be provided at the end of each construction sequence and between the concrete slab and adjacent structures. Expansion joints, where required, should be filled with a ½-inch thick asphalt impregnated fiber. Concrete should be cured by pro-tecting against loss of moisture, rapid temperature changes, and mechanical injury for at least three days after placement.
CONSTRUCTION OBSERVATIONS
We recommend that CTL|T be retained to provide construction observation and materi-als testing services for the project. This would allow us the opportunity to verify whether soil conditions are consistent with those found during this investigation. If others perform these ob-servations, they must accept responsibility to judge whether the recommendations in this report remain appropriate. It is also beneficial to projects, from economic and practical standpoints, when there is continuity between engineering consultation and the construction observation and materials testing phases.
GEOTECHNICAL RISK
The concept of risk is an important aspect of any geotechnical evaluation. The primary reason for this is that the analytical methods used to develop geotechnical recommendations do not comprise an exact science. We never have complete knowledge of subsurface conditions.
Our analysis must be tempered with engineering judgment and experience. Therefore, the rec-ommendations in any geotechnical evaluation should not be considered risk-free. We cannot
CH SP ACQUISITION, LLC 17 of 18
CTL|T PROJECT NO. MT01140.000-125
provide a guarantee that the interaction between the soils and the proposed structures will lead to performance as desired or intended. Our recommendations represent our judgment of those measures that are necessary to increase the chances that the structure will perform satisfacto-rily. It is critical that all recommendations in this report are followed.
LIMITATIONS
This report has been prepared for the exclusive use of CH SP Acquisition, LLC. The in-formation, conclusions, and recommendations provided herein are based upon consideration of many factors including, but not limited to, the type of structure proposed, the geologic setting, and the subsurface conditions encountered. Standards of practice evolve in geotechnical engi-neering. The recommendations provided in this report are appropriate for about three years. If the proposed project is not constructed within about three years, we should be contacted to de-termine if we should update this report.
Our exploratory pits and borings provide a reasonable characterization of subsurface conditions at the site. Variations in the subsurface conditions not indicated by the exploratory pits and borings will occur. The recommendations in the report are based on the construction as currently planned. CTL|T should be contacted to participate in design-team meetings so we can provide geotechnical/geo-structural engineering input.
This geotechnical engineering investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing un-der similar conditions in the locality of this project. No warranty, express or implied, is made.
Please contact us if we can be of service in discussing the contents of this report.
CH SP ACQUISITION, LLC 18 of 18
CTL|THOMPSON, INC.
Leyla Safari, P.E.
Project Manager lsafari@ctlthompson.com
Reviewed By:
Alan J. Lisowy, P.E. James D. Kellogg, P.E.
Principal Engineer Principal Engineer alisowy@ctlthompson.com jkellogg@ctlthompson.com
LS:AJL:JDK
cc: jolsen@lonemountainland.com tdecker@lonemountainland.com
6/7/2024
6/7/2024 mailto:lsafari@ctlthompson.com mailto:alisowy@ctlthompson.com mailto:jkellogg@ctlthompson.com mailto:jolsen@lonemountainland.com mailto:tdecker@lonemountainland.com
0 7
98.00'
10.00'
(TYP.)
.0
(T
Y P
8.00'
51.95'
35.34'
34.50'
32.49'
.3
34.5 0'
.4
7.97'
29.03'
9.
.0
0'
37.28'
.6
9.87'
.2
6.50'
51.95'
7.97'
29.03'
40.00'
40.00'
0.
18.14'
.0
15.40'
.5
7'
3.
.6
'23.06'
12.32'5.66'
.3
8 '
.4
4.00'
7.
.4
104°'
.0
16.82'
20.00'
(TYP.)
.0
(T Y
P
14.00'
3.00'(TYP.)
40.00'
SPANISH PEAKS
FIRE STATION
PROPERTY
LINE (TYP.)
IN
SPIR
ATI
O N P
OIN
T R
O
AD
SOUTH FORK ROAD
10' UTILITY EASEMENT
20' UTILITY
EASEMENT
EX. 60' ACCESS
EASEMENT
10' UTILITY EASEMENT
20' UTILITY
EASEMENT
30' UTILITY
EASEMENT
LOT 1
3.005 ACRES
SPANIS
H P
EAKS E
STATES SUBDIVISION
PHASE 7
PLAT J-737
TRACT 1
LESS S
PANIS
H P
EAKS R
ESORT PHASE 1B
MATCH EXISTING
SAW CUT ASPHALT
EX. 1' CONTOUR (TYP.)
FINISH 1' CONTOUR (TYP.)
152 L.F. OF 6" WATER SERVICE
NEW (FOUR) 1,000-GAL
PROPANE TANKS
NEW GENERATOR BUILDING
NEW GAS SERVICE
NEW BOULDER STACK RETAINING WALL
(TYP.) (SEE LANDSCAPE PLANS)
RELOCATED NEW 2" BLOW OFF VALVE
CONNECT TO EX. BLOWOFF VALVE SERVICE
NEW 6" FIRE HYDRANT ASSEMBLY
NEW 6" GATE VALVE
NEW BOLLARD (TYP.)
NEW STOP SIGN
CONNECT TO EX. WATER MAIN
NEW ASPHALT
PAVING
NEW ASPHALT
PAVING
NEW CONCRETE
PAVING
NEW CONCRETE
PAVING
CONNECT TO EX. WATER MAIN
6" GATE VALVE
NEW 2" EFLUENT SERVICE
(SEE PLAN AND PROFILE)
RELOCATED 8" EFFLUENT MAIN
(SEE PLAN AND PROFILE)
NEW 1,000-GAL SEPTIC TANK
50 L.F. OF 4" SCH. 40 PVC SEWER SERVICE
SLOPED AT14" PER FOOT MINIMUM TO SEPTIC
TANK. CLEANOUT WITHIN 36" OF BUILDING
NEW 4 L.F. OF 4" SCH 40 PVC SLOPED AT
18" PER FOOT MINIMUM TO DOSE TANK
NEW 1,000-GAL DOSE TANK
NEW STOP SIGN
NEW STOP SIGN
MATCH EXISTING
SAW CUT ASPHALT
MATCH EXISTING
SAW CUT ASPHALT
FFE = 7467.05
EX. WATER MAIN
CONTRACTOR TO VERIFY DEPTH
INSULATE WHEN LESS THAN 7.5' OF COVER
NOTIFY ENGINEER WHEN LESS THAN 5.0' OF COVER
EX. WATER MAIN
CONTRACTOR TO VERIFY DEPTH
INSULATE WHEN LESS THAN 7.5' OF COVER
NOTIFY ENGINEER WHEN LESS THAN 5.0' OF COVER
NEW ADVANCED FIRE STATION
WARNING SIGN W11-8
ON
TRACT 1
LESS S
PANIS
H P
EAKS R
ESORT PHASE 1B
6' WIDE THICKENED
EDGE WALK
THICKENED
EDGE WALK
ADA
R10.00' RAMP
EX. 30' UTILITY
EASEMENT
60' ACCESS AND
UTILITY EASEMENT
NEW STORMWATER EASEMENT
RAISE EX. GATE VALVE
TO FINISH GRADE
NEW 4" PAINTED
YELLOW STRIPE (TYP.)
NEW 4" PAINTED
YELLOW STRIPE
3' O.C. (TYP.)
NEW PAINTED INTERNATIONAL
DISABLED SYMBOL
NEW 10' UTILITY
EASEMENT
CTL|T PROJECT NO. MT01140.000-125
FIG. 4
7,455
7,460
7,465
7,470
7,475
7,455
7,460
7,465
7,470
7,475
LEGEND:
FILL, CLAY, SANDY WITH GRAVEL, MOIST, BROWN, GRAY.
NOTES:
Summary Logs of Exploratory Pits
E
LE
V A
T
IO
N
F E
E T
E
LE
V A
T
IO
N
F E
E T
S-1
EL.7466
S-2
EL.7473
WEATHERED CLAYSTONE, SLIGHTLY MOIST TO MOIST,
BROWN, DARK BROWN, GRAY, RUST.
1. THE EXPLORATORY PITS WERE EXCAVATED
ON MARCH 7, 2024 WITH A TRACKHOE.
2. GROUNDWATER WAS NOT ENCOUNTERED
DURING EXCAVATION. PITS WERE BACKFILLED IMMEDIATELY
AFTER EXPLORATORY OPERATIONS WERE COMPLETED.
3. PIT ELEVATIONS ARE APPROXIMATE AND
ESTIMATED BY REFERENCING GRADING PLANS.
4. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS,
LIMITATIONS, AND CONCLUSIONS AS CONTAINED
IN THIS REPORT.
BEDROCK, CLAYSTONE, SCATTERED CARBONACEOUS
LENSES, OCCASIONAL SANDSTONE LAYERS, HARD TO
VERY HARD, SLIGHTLY MOIST TO MOIST, GRAY-BROWN,
BROWN, DARK BROWN, LIGHT TO DARK GRAY, BLACK.
INDICATES BULK SAMPLE FROM EXCAVATED SOILS.
CLAY, SLIGHTLY SANDY WITH GRAVEL, LEAN TO HIGHLY
PLASTIC, STIFF TO VERY STIFF, SLIGHTLY MOIST TO MOIST,
BROWN, GRAY, DARK BROWN, GRAY, RUST (CL, CH).
CTL|T PROJECT NO. MT01140.000-125
FIG. 5
LEGEND:
TOPSOIL.
Summary Logs of Exploratory Borings
CLAY, SLIGHTLY SANDY WITH GRAVEL, LEAN TO HIGHLY PLASTIC, STIFF TO
VERY STIFF, SLIGHTLY MOIST TO MOIST, BROWN, DARK BROWN, GRAY,
RUST (CL, CH).
INDICATES BULK SAMPLE OBTAINED FROM AUGER CUTTINGS.
NOTES:
WEATHERED CLAYSTONE, SLIGHTLY MOIST TO MOIST, BROWN, DARK
BROWN, GRAY, RUST.
1. BORINGS WERE DRILLED MARCH 11 AND 12, 2024 WITH A TRACK-MOUNTED
DRILL RIG AND 6-INCH DIAMETER, CONTINUOUS-FLIGHT, HOLLOW-STEM AUGER.
2. GROUNDWATER WAS NOT ENCOUNTERED IN OUR BORINGS AT THE TIME OF DRILLING.
BORINGS WERE BACKFILLED IMMEDIATELY AFTER EXPLORATORY
DRILLING OPERATIONS WERE COMPLETED.
3. BORING ELEVATIONS ARE APPROXIMATE AND ESTIMATED BY REFERENCING GRADING PLANS.
4. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS,
LIMITATIONS, AND CONCLUSIONS AS CONTAINED IN THIS REPORT.
7,440
7,445
7,450
7,455
7,460
7,465
7,470
7,475
7,480
7,485
7,440
7,445
7,450
7,455
7,460
7,465
7,470
7,475
7,480
7,485 E
LE
V
A T
IO
N
F
E E
T
E
LE
V A
T
IO
N
F E
E T
8/12
50/12
50/12
50/6
50/4
TH-1
EL.7481
23/12
31/12
41/12
26/12
50/5
50/3
TH-2
EL.7482
19/12
50/6
TH-3
EL.7466
INDICATES PRACTICAL AUGER REFUSAL.
DRIVE SAMPLE. THE SYMBOL 72/12 INDICATES 72 BLOWS OF A 140-POUND
HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.0-INCH O.D.
SPLIT-SPOON SAMPLER 12 INCHES.
DRIVE SAMPLE. THE SYMBOL 8/12 INDICATES 8 BLOWS OF A 140-POUND
HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D.
CALIFORNIA-BARREL SAMPLER 12 INCHES.
BEDROCK CLAYSTONE, SCATTERED CARBONACEOUS LENSES, OCCASIONAL
SANDSTONE LAYERS, HARD TO VERY HARD, SLIGHTLY MOIST TO MOIST,
GRAY-BROWN, BROWN, DARK BROWN, LIGHT TO DARK GRAY, BLACK.
Sample of CLAYSTONE DRY UNIT WEIGHT= 115 PCF
From TH-1 AT 15 FEET MOISTURE CONTENT= 16.1 %
Sample of CLAYSTONE DRY UNIT WEIGHT= 117 PCF
From TH-2 AT 15 FEET MOISTURE CONTENT= 12.4 %
CH SP ACQUISITION, LLC
SOUTH FORK ROAD FIRE STATION
CTL|T PROJECT NO. MT01140.000-125
APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
C O
M P
R E
S S
IO
N
E
X P
A N
S
IO
N
Swell Consolidation Test Results
FIG. 6
C O
M P
R E
S S
IO
N
E
X P
A N
S
IO
N
-4
-3
-2
-1
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
Sample of CLAYSTONE DRY UNIT WEIGHT= 110 PCF
From TH-3 AT 5 FEET MOISTURE CONTENT= 17.2 %
CH SP ACQUISITION, LLC
SOUTH FORK ROAD FIRE STATION
CTL|T PROJECT NO. MT01140.000-125
APPLIED PRESSURE - KSF
C O
M P
R E
S S
IO
N
E
X P
A N
S
IO
N
Swell Consolidation Test Results
FIG. 7
-8
-7
-6
-5
-4
-3
-2
-1
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
Sample of CLAY, GRAVELLY, HIGHLY PLASTIC (CH) GRAVEL 18 % SAND 6 % From S - 1 AT 0-5 FEET SILT & CLAY 76 % LIQUID LIMIT 68
PLASTICITY INDEX 52
Sample of GRAVEL % SAND % From SILT & CLAY % LIQUID LIMIT
PLASTICITY INDEX
CH SP ACQUISITION, LLC
SOUTH FORK ROAD FIRE STATION
CTL|T PROJECT NO. MT01140.000-125
FIG. 8
Gradation Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
5"
6"
8"
.001
45 MIN.
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARS
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PE
R
C
EN
T
PA
SS
IN
G
PE
R
C
EN
T R
ET
AI
N
ED
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
5"
6"
8"
.001
45 MIN.
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARS
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PE
R
C
EN
T
PA
SS
IN
G
PE
R
C
EN
T R
ET
AI
N
ED
0 7
98.00'
10.00'
(TYP.)
.0
(T
Y P
8.00'
51.95'
35.34'
34.50'
32.49'
.3
34.5 0'
.4
7.97'
29.03'
9.
.0
0'
37.28'
.6
9.87'
.2
6.50'
51.95'
7.97'
29.03'
40.00'
40.00'
0.
18.14'
.0
15.40'
.5
7'
3.
.6
'23.06'
12.32'5.66'
.3
8 '
.4
4.00'
7.
.4
104°'
.0
16.82'
20.00'
(TYP.)
.0
(T Y
P
14.00'
3.00'(TYP.)
40.00'
SPANISH PEAKS
FIRE STATION
PROPERTY
LINE (TYP.)
IN
SPIR
ATI
O N P
OIN
T R
O
AD
SOUTH FORK ROAD
10' UTILITY EASEMENT
20' UTILITY
EASEMENT
EX. 60' ACCESS
EASEMENT
10' UTILITY EASEMENT
20' UTILITY
EASEMENT
30' UTILITY
EASEMENT
LOT 1
3.005 ACRES
SPANIS
H P
EAKS E
STATES SUBDIVISION
PHASE 7
PLAT J-737
TRACT 1
LESS S
PANIS
H P
EAKS R
ESORT PHASE 1B
MATCH EXISTING
SAW CUT ASPHALT
EX. 1' CONTOUR (TYP.)
FINISH 1' CONTOUR (TYP.)
152 L.F. OF 6" WATER SERVICE
NEW (FOUR) 1,000-GAL
PROPANE TANKS
NEW GENERATOR BUILDING
NEW GAS SERVICE
NEW BOULDER STACK RETAINING WALL
(TYP.) (SEE LANDSCAPE PLANS)
RELOCATED NEW 2" BLOW OFF VALVE
CONNECT TO EX. BLOWOFF VALVE SERVICE
NEW 6" FIRE HYDRANT ASSEMBLY
NEW 6" GATE VALVE
NEW BOLLARD (TYP.)
NEW STOP SIGN
CONNECT TO EX. WATER MAIN
NEW ASPHALT
PAVING
NEW ASPHALT
PAVING
NEW CONCRETE
PAVING
NEW CONCRETE
PAVING
CONNECT TO EX. WATER MAIN
6" GATE VALVE
NEW 2" EFLUENT SERVICE
(SEE PLAN AND PROFILE)
RELOCATED 8" EFFLUENT MAIN
(SEE PLAN AND PROFILE)
NEW 1,000-GAL SEPTIC TANK
50 L.F. OF 4" SCH. 40 PVC SEWER SERVICE
SLOPED AT14" PER FOOT MINIMUM TO SEPTIC
TANK. CLEANOUT WITHIN 36" OF BUILDING
NEW 4 L.F. OF 4" SCH 40 PVC SLOPED AT
18" PER FOOT MINIMUM TO DOSE TANK
NEW 1,000-GAL DOSE TANK
NEW STOP SIGN
NEW STOP SIGN
MATCH EXISTING
SAW CUT ASPHALT
MATCH EXISTING
SAW CUT ASPHALT
FFE = 7467.05
EX. WATER MAIN
CONTRACTOR TO VERIFY DEPTH
INSULATE WHEN LESS THAN 7.5' OF COVER
NOTIFY ENGINEER WHEN LESS THAN 5.0' OF COVER
EX. WATER MAIN
CONTRACTOR TO VERIFY DEPTH
INSULATE WHEN LESS THAN 7.5' OF COVER
NOTIFY ENGINEER WHEN LESS THAN 5.0' OF COVER
NEW ADVANCED FIRE STATION
WARNING SIGN W11-8
ON
TRACT 1
LESS S
PANIS
H P
EAKS R
ESORT PHASE 1B
6' WIDE THICKENED
EDGE WALK
THICKENED
EDGE WALK
ADA
R10.00' RAMP
EX. 30' UTILITY
EASEMENT
60' ACCESS AND
UTILITY EASEMENT
NEW STORMWATER EASEMENT
RAISE EX. GATE VALVE
TO FINISH GRADE
NEW 4" PAINTED
YELLOW STRIPE (TYP.)
NEW 4" PAINTED
YELLOW STRIPE
3' O.C. (TYP.)
NEW PAINTED INTERNATIONAL
DISABLED SYMBOL
NEW 10' UTILITY
EASEMENT
CTL|T PROJECT NO. MT01140.000-125
FIG. 4
7,455
7,460
7,465
7,470
7,475
7,455
7,460
7,465
7,470
7,475
LEGEND:
FILL, CLAY, SANDY WITH GRAVEL, MOIST, BROWN, GRAY.
NOTES:
INDICATES BULK SAMPLE FROM EXCAVATED SOILS.
Summary Logs of Exploratory Pits
E
LE
V A
T
IO
N
F E
E T
E
LE
V A
T
IO
N
F E
E T
S-1
EL.7466
S-2
EL.7473
CLAY, SLIGHTLY SANDY WITH GRAVEL, LEAN TO HIGHLY
PLASTIC, VERY STIFF, SLIGHTLY MOIST…
This is the start of the file's text. The full file is on GovTribe.
File details come from the government source that posted it. Updated .