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HomeMy WebLinkAboutSoils Report 12.02.2019CTL I THOMPSON nw.go J GEOTECHNICAL ENGINEERING INVESTIGATION STATION 84 — WEST END 5449 COUNTY ROAD 154 GARFIELD COUNTY, COLORADO Prepared For: CARBONDALE AND RURAL FIRE PROTECTION DISTRICT 301 Meadowood Drive Carbondale, CO 81623 Attention: Rob Goodwin Chief Project No. GS06418.001-125 December 2, 2019 234 Center Drive I Glenwood Springs, Colorado 81601 Telephone: 970-945-2809 Fax: 970-945-7411 TABLE OF CONTENTS SCOPE 1 SUMMARY OF CONCLUSIONS 1 SITE CONDITIONS 2 PROPOSED CONSTRUCTION 3 SITE GEOLOGY 4 SUBSURFACE CONDITIONS 4 EARTHWORK 5 Subexcavation and Structural Fill 6 Foundation Wall Backfill 7 FOUNDATION 7 SLAB -ON -GRADE CONSTRUCTION. 8 BELOW -GRADE CONSTRUCTION 9 SURFACE DRAINAGE 9 PAVEMENTS 10 CONCRETE 11 CONSTRUCTION OBSERVATIONS - 12 GEOTECHNICAL RISK 12 LIMITATIONS 13 FIGURE 1 — VICINITY MAP FIGURE 2 — AERIAL PHOTOGRAPH FIGURE 3 — PROPOSED BUILDING FOOTPRINT FIGURE 4 — SUMMARY LOGS OF EXPLORATORY PITS FIGURE 5 — GRADATION TEST RESULTS TABLE 1 — SUMMARY OF LABORATORY TEST RESULTS APPENDIX A — CONSTRUCTION AND PAVEMENT MATERIALS RECOMMENDATIONS APPENDIX B — PAVEMENT MAINTENANCE RECOMMENDATIONS CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 l I SCOPE This report presents the results of our geotechnical engineering investiga- tion for the planned addition to the Carbondale and Rural Fire Protection Dis- trict's "Station 84 — West End" at 5449 County Road 154 in Garfield County, Col- orado. We conducted this investigation to evaluate subsurface conditions at the site and provide geotechnical engineering recommendations for the proposed construction. The scope of our investigation was set forth in our Proposal No. GS 19-0281. Our report was prepared from data developed during our field ex- ploration, laboratory testing, engineering analysis, and our experience with simi- lar conditions. This report includes a description of the subsurface conditions en- countered in our exploratory pits and presents geotechnical engineering recom- mendations for design and construction of foundations, floor systems, pavement section alternatives, and details influenced by the subsoils. A summary of our conclusions is presented below. SUMMARY OF CONCLUSIONS 1. Subsurface conditions encountered in our exploratory pits, TP -1 and TP -2, in the area of the proposed building consisted of about 4 inches of sandy clay "topsoil" and 1.5 to 3 feet of silty sandy clay underlain by silty gravel, cobbles and boulders to the maximum ex- cavated depth of 8 feet. TP -3, to the west of the existing apparatus bays, exposed about 4 inches of topsoil, 3 feet of sandy clay, and 4 feet of silty sand, underlain by silty gravel, cobbles and boulders to the total explored depth of 8 feet. Free groundwater was not en- countered in our exploratory pits. 2. Our exploratory pits indicate the silty gravel and cobble soil, which has good foundation support properties, is near the ground surface in the area of the proposed building addition. We recommend con- structing the addition on a footing foundation supported by the un- disturbed, silty gravel and cobble soil. Where clay soils are found at planned footing elevations, the clay should be subexcavated to expose the underlying gravel and cobble soil. Foundation eleva- tions can be re -attained with densely -compacted, granular structur- CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001.125 1 al fill. Design and construction criteria for footings are presented in the report. 3. Floors in the building addition are planned as slabs -on -grade. The sandy clay soil at the site possesses relatively poor slab support characteristics as compared to the silty gravel and cobble. We rec- ommend removal of clay soils below the building floor slabs to a depth of at least 2 feet and replacement with densely -compacted, granular structural fill. Additional discussion is in the report. 4. Most pavement areas at the site will be subject to traffic from heavy fire trucks that will turn and stop. We recommend a minimum pavement section of 6 inches of Portland Cement Concrete. 5. Surface drainage is critical for building performance. Site grading should be designed and constructed to convey surface water off pavements and away from the building. SITE CONDITIONS The Carbondale and Rural Fire Protection District's "Station 84 — West End" is located at 5449 County Road 154 in Garfield County, Colorado. A vicinity map with the location of the site is provided on Figure 1. The parcel is bounded by County Road 154 at the east and a mobile home park to the south. The Glenwood Ditch trends along the northwest property boundary. The property is a triangular-shaped, 1.68 -acre parcel. Existing buildings for apparatus storage and crew housing. An aerial photograph of the site is on Figure 2. A concrete -paved access drive and parking area is east of the apparatus bays. Ground surface appears to slope gently down to the west at grades less than 5 percent. Vegeta- tion on the site consists of irrigated grass and scattered trees. Several inches of snow covered the ground surface at the time of our subsurface investigation. A photograph of the site is below. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 2 Looking south from TP -1. PROPOSED CONSTRUCTION The currently -proposed building will be northwest of the existing apparatus bays. A hallway will connect the new and existing buildings. The proposed building footprint, as indicated by the client, is shown on Figure 3. The construc- tion will include additional apparatus bays and gear storage. It appears that addi- tional vehicle parking will be south of the existing concrete -pavement area. The new building areas will be one-story with slab -on -grade floors. No below -grade areas, such as basements or crawl spaces, are planned. We expect elevations of bottoms of footings will be about 3 to 4 feet below existing ground surface. Foundation loads are expected to vary between 1,000 and 3,000 pounds per lin- ear foot of foundation wall with maximum interior column loads of up to 30 kips. We should be provided with construction plans as they are developed so that we can provide geotechnical/geostructural engineering input. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 3 SITE GEOLOGY As part of our investigation, we reviewed the open file geologic map and re- port by the Colorado Geology Survey (CGS), titled, "Geologic Map of the Cattle Creek Quadrangle, Garfield County, Colorado", by Kirkham, Streufert, Hemborg, and Stelling (dated 2014). The soils at the site are mapped as intermediate terrace alluvium deposits of the late Pleistocene Epoch. The deposits are generally poorly - sorted, clast-supported, occasionally boulder, cobble and gravel with a sand to silt matrix. The soils are underlain at depth by bedrock of the Eagle Valley Evaporite formation. The natural gravel and cobble soil found in our expoloratory pits is con- sistent with the terrace alluvium described on the geologic mapping. SUBSURFACE CONDITIONS Subsurface conditions at the site were investigated by excavating three ex- ploratory pits (TP -1 through TP -3) with a trackhoe at the approximate locations shown on Figure 2. Exploratory excavation operations were directed by our engi- neer who logged the soils and obtained samples for laboratory testing. Samples ob- tained from our pits were returned to our laboratory where they were visually classi- fied and typical samples selected for testing. Graphic logs of the soils encountered in our exploratory pits are presented on Figure 4. Subsurface conditions encountered in our exploratory pits, TP -1 and TP -2, in the area of the proposed building consisted of about 4 inches of sandy clay "topsoil" and 1.5 to 3 feet of silty sandy clay underlain by silty gravel, cobbles and boulders to the maximum excavated depth of 8 feet. TP -3, to the west of the existing apparatus bays, exposed about 4 inches of topsoil, 3 feet of sandy clay, and 4 feet of silty sand, underlain by silty gravel, cobbles and boulders to the total explored depth of 8 feet. Free groundwater was not encountered in our exploratory pits. The pits were CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 4 backfilled immediately after exploratory excavation was completed. A photograph of soils exposed during excavation of TP -1 is below. Soils exposed in TP -1. We performed laboratory testing on samples of the subsoils obtained from our exploratory pits. Two samples of the silty gravel and cobble soil selected for gradation analysis contained 73 and 77 percent gravel, 19 and 23 percent sand, and 4 percent silt and clay (passing the No. 200 sieve). Gradation tests are not inclusive of gravel and cobbles larger than about 5 inches. Engineering index testing on a sample of the silty sandy clay indicated a liquid limit of about 25 per- cent and a plasticity index of about 5 percent. Gradation test results are shown on Figure 5. Laboratory test results are summarized on Table I. EARTHWORK We anticipate that excavations for the proposed building can be accom- plished using conventional, heavy-duty excavation equipment. Sides of excava- CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 5 tions must be sloped or braced to meet local, state and federal safety regula- tions. The clay and gravel soils will likely classify as Type B or Type C, respec- tively, based on OSHA standards governing excavations. Temporary slopes deeper than 4 feet and above groundwater should be no steeper than 1 to 1 (hor- izontal to vertical) in Type B soils and 1.5 to 1 in Type C soils. Contractors are responsible for site safety and providing and maintaining safe and stable excava- tions. Contractors should identify the soils encountered and ensure that OSHA standards are met. Our exploratory pits did not penetrate groundwater at the time of excava- tion. We do not expect groundwater to affect excavations to the proposed depths at the site. Excavations should be sloped to a gravity discharge or to a tempo- rary sump where water from precipitation can be removed by pumping. Subexcavation and Structural Fill Our exploratory pits indicate the silty gravel and cobble soil, which has good building support properties, is near the ground surface in the area of the proposed building addition. Where clay soils are found at planned footing eleva- tions, the clay should be subexcavated to expose the underlying gravel and cob- ble soil. We recommend removal of clay soils below the building floor slabs to a depth of at least 2 feet. The subexcavated clay should be replaced with densely - compacted, granular structural fill. We recommend that structural fill consist of a CDOT aggregate base course or similar soil. Structural fill should be placed in loose lifts of 10 inches thick or less, moisture conditioned to within 2 percent of optimum moisture -content, and com- pacted to at least 98 percent of standard Proctor (ASTM D 698) maximum dry density. Moisture content and density of structural fill should be checked by a CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 6 representative of our firm during placement. Observation of the compaction pro- cedure is necessary. Foundation Wall Backfill Proper placement and compaction of foundation backfill is important to re- duce infiltration of surface water and settlement of backfill. The on-site soils can be reused as backfill, provided they are free of rocks larger than 6 inches in di- ameter, organics and debris. Backfill should be placed in loose lifts of approxi- mately 10 inches thick or less, moisture -conditioned to within 2 percent of opti- mum moisture content, and compacted to at least 95 percent of maximum stand- ard Proctor dry density (ASTM D 698). Moisture content and density of the back- fill should be checked during placement by a representative of our firm. FOUNDATION Our exploratory pits indicate the silty gravel and cobble soil, which has good foundation support properties, is near the ground surface in the area of the proposed building addition. We recommend constructing the addition on a foot- ing foundation supported by the undisturbed, silty gravel and cobble soil. Where clay soils are found at planned footing elevations, the clay should be subexca- vated to expose the underlying gravel and cobble soil. Footing elevations can be re -attained with densely -compacted, granular structural fill. The structural fill should be in accordance with recommendations in the Subexcavation and Struc- tural Fill section. Settlement of the addition due to new foundation loads will be differential with respect to the existing building. We recommend that a joint be constructed that can allow movement between the new and existing structures. Recommended design and construction criteria for footings are presented below. 1. Footing foundations should be supported by the undisturbed, gravel and cobble soil or densely -compacted, granular structural fill. Soils CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 7 loosened during excavation or the forming process for the footings should be removed or the soils can be re -compacted prior to plac- ing concrete. 2. Footings supported by the gravel and cobble soil or densely - compacted, granular structural fill can be designed for a maximum allowable soil pressure of 4,000 psf. 3. A friction factor of 0.45 can be used to calculate resistance to slid- ing between concrete footings and the soil. Continuous wall footings should have a minimum width of at least 16 inches. Foundations for isolated columns should have minimum dimensions of 24 inches by 24 inches. Larger sizes may be re- quired, depending upon foundation loads. 5. Grade beams and foundation walls should be well reinforced, top and bottom, to span undisclosed loose or soft soil pockets. We recommend reinforcement sufficient to span an unsupported dis- tance of at least 12 feet. 6. The soils under exterior footings should be protected from freezing. We recommend the bottom of footings be constructed at a depth of at least 36 inches below finished exterior grades for frost protection. The Garfield County building department should be consulted re- garding required frost protection depth. SLAB -ON -GRADE CONSTRUCTION Floors in the building addition are planned as slabs -on -grade. The sandy clay soil at the site possesses relatively poor slab support characteristics as compared to the silty gravel and cobble. We recommend removal of clay soils below the building floor slabs to a depth of at least 2 feet and replacement with densely -compacted, granular structural fill. Structural fill below slabs should be in accordance with recommendations in the Subexeavation and Structural Fill section. We recommend the following precautions for slab -on -grade construction at this site. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 8 1. Slabs should be separated from wall 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 poured. 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 patio and porch slabs should be isolated from the building. These slabs should be well -reinforced to function as independent units. Frequent control joints should be provided, in accordance with American Concrete Institute (ACI) recommendations, to reduce problems associated with shrinkage and curling. BELOW -GRADE CONSTRUCTION We understand that no below -grade areas, such as a basement or crawl space, are planned. If construction plans change to include below -grade areas, we should be informed so that we can provide recommendations for lateral earth pressures and subsurface drainage. SURFACE DRAINAGE Surface drainage is critical to the performance of foundations, floor slabs, and concrete flatwork. Surface drainage should be designed to provide rapid runoff of surface water away from the building. Proper surface drainage and irri- gation practices can help control the amount of surface water that penetrates to foundation levels and contributes to settlement or heave of soils and bedrock that support foundations and slabs -on -grade. Positive drainage away from the foun- dation and avoidance of irrigation near the foundation also help to avoid exces- sive wetting of backfill soils, which can lead to increased backfill settlement and possibly to higher lateral earth pressures, due to increased weight and reduced strength of the backfill. We recommend the following precautions. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84- WEST END PROJECT NO. GS06418.001-125 9 The ground surface surrounding the exterior of the building should be sloped to drain away from the building in all directions. We rec- ommend a minimum constructed slope of at least 12 inches in the first 10 feet (10 percent) in landscaped areas around the structure. 2. Roof downspouts and drains should discharge well beyond the lim- its of all backfill. Splash blocks and/or extensions should be provid- ed at all downspouts so water discharges onto the ground beyond the backfill. Landscaping should be carefully designed and maintained to mini- mize irrigation. Plants placed close to foundation walls should be limited to those with low moisture requirements. Sprinklers should not discharge within 5 feet of foundations. Plastic sheeting should not be placed beneath landscaped areas adjacent to foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet still allow natural evaporation to occur. PAVEMENTS Subsurface information indicates the subgrade soils at the site consist of silty sandy clay. These soils generally classify as A-4 based on the AASHTO classifica- tion system. We estimated an R -value of 10 for the silty sandy clay soils, based on our laboratory testing and experience with similar soils. Most pavement areas will be subject to traffic from heavy fire trucks that will turn and stop. We estimated an Equivalent Single Axle Load (ESAL) Value of 109,500 for the pavements at the site. Based on our calculations, we recommend a minimum pavement section of 6 inches of Portland Cement Concrete Pavement. The performance of a pavement system is as much a function of the quality of the paving materials and construction as the support characteristics of the sub - grade. If the pavement system is constructed of inferior material, then the life and serviceability of the pavement will be substantially reduced. We recommend that subgrade soils below pavements be scarified to a depth of 8 inches, moisture- CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 10 treated, and recompacted as structural fill. We have included criteria for pavement material properties and construction for rigid pavements in Appendix A. We recommend concrete contain a minimum of 610 pounds of cement per cubic yard and between 5 and 7 percent entrained air. A mix design should be pre- pared for this project using the aggregate and cement that will be used during con- struction. Control joints should separate concrete pavements into panels as rec- ommended by ACI. No de-icing salts should be used on paving concrete for at least one year after placement. Pavement maintenance recommendations are included as Appendix B. 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 rec- ommend drainage be designed for rapid removal of surface runoff from pave- ment surfaces. Final grading should be carefully controlled so that design cross - slope is maintained and low spots in the subgrade which could trap water are eliminated. CONCRETE Concrete in contact with soil can be subject to sulfate attack. We meas- ured a soluble sulfate concentration of 0.00 percent in a sample of soil from this site, which is considered a low level. The American Concrete Institute indicates that for this level of sulfate concentration any type of cement can be used for concrete in contact with the subsoils. In our experience, 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 deterioration, the water-to-cementitious CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84- WEST END PROJECT NO. GS06418.001-125 11 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% +1- 1.5%. CONSTRUCTION OBSERVATIONS We recommend that CTL 1 Thompson, Inc. be retained to provide con- struction observation services. This would allow us the opportunity to verify whether soil conditions are consistent with those found during this investigation. If others perform these observations, they must accept responsibility to judge whether the recommendations in this report remain appropriate. It is also benefi- cial to projects, from cost and practical standpoints, when there is continuity be- tween engineering consultation and the construction observation and materials testing phases. GEOTECHNICAL RISK The concept of risk is an important aspect with any geotechnical evalua- tion primarily because the methods used to develop geotechnical recommenda- tions do not comprise an exact science. We never have complete knowledge of subsurface conditions. Our analysis must be tempered with engineering judg- ment and experience. Therefore, the recommendations presented in any ge- otechnical evaluation should not be considered risk-free. We cannot provide a guarantee that the interaction between the soils and a proposed structure will be as desired or intended. Our recommendations represent our judgment of those measures that are necessary to increase the chances that the structures will per- form satisfactorily. It is critical that all recommendations in this report are followed during construction. Owners must assume responsibility for maintaining the structure and use appropriate practices regarding drainage and landscaping. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06416.001-125 12 This report has been prepared for the exclusive use of the client. The in- formation, conclusions, and recommendations presented herein are based upon consideration of many factors including, but not limited to, the type of structures proposed, the geologic setting, and the subsurface conditions encountered. Standards of practice continuously change in the area of geotechnical engineer- ing. The recommendations provided are appropriate for about three years. If the proposed building is not constructed within about three years, we should be con- tacted to determine if we should update this report. LIMITATIONS Our exploratory pits provide a reasonably accurate picture of subsurface conditions. Variations in the subsurface conditions not indicated by our pits will occur. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing under similar conditions in the locality of this project. No warranty, express or implied, is made. If we can be of further service in discussing the contents of this report, please call. CTL 1 THOMPSON, INC. Ryan R. Barbone, E.I.T. Staff Engineer RRB:JDK:ac cc: Via email rgoodwincarbondalefire.orq CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 Reviewed by: - !4r't amesD. Keiogg,?298:„),.44 'vision Manag rt,: Z 1 13 iT SCALE: 1' = 1,000' CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END Protect No. GS06418.001-125 Vicinity Map Fig. 1 SCALE: 1' = 60' NOTE: IMAGE FROM GOOGLE EARTH. TP -1 APPROXIMATE LOCATION OF EXPLORATORY PIT. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 -WEST END Project No. GS06418.001-125 Aerial Photograph Flg. 2 i SCALE: 1' = 60' WEST END STATION #84 9Ionwp0dSm754C 151 pnipsad 54 LSITE PLAN SITE AREA: 76,928 S F CREW QUARTERS: 1,559 S F. sTAT10N.Bn: 2,577 S F. NEW APPARATUS BAYS: 1,8002F - FUTURE EXPANSION: 2,000 S.F. G--- / '`L� 92710 rzo ARE • EMS • RESCUE TP - I� MISQ(STORAGE I REW0AYS •m:, LW RR ••-. _' I Tams, .u1URE ! ,? OTIg R!1wa. 1 sTA11Ory •1 trvnnsbu j i a s H Lazy F Drive NOTE: IMAGE PROVIDED BY CLIENT. TP -1 APPROXIMATE LOCATION [ OF EXPLORATORY PIT. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END Project No. GS06418.001-125 Proposed Building Footprint Fig. 3 TP -1 TP -2 TP -3 EL. 6006 EL. 6005 EL. 6006 6,010 6,010 - LEGEND: 6,005 w - LL Or 6,000 5,995 CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END CTLIT PROJECT NO. GS06418.001.125 6,005 - 6,000 5,995 W W LL Z 0 W rj SANDY CLAY "TOPSOIL", MOIST, DARK BROWN /1 CLAY, SANDY, SILTY, GRAVEL, MEDIUM STIFF, MOIST, DARK BROWN. (CL -ML) SAND, SILTY, GRAVEL AND COBBLES, MEDIUM DENSE, MOIST, BROWN. (SM) GRAVEL, SLIGHTLY SILTY, SAND, COBBLES A. AND BOULDERS, MEDIUM DENSE, MOIST, • BROWN, GRAY. (GP -GM) b NOTES: INDICATES HAND DRIVE SAMPLE INDICATES BULK SAMPLE FROM EXCAVATED SOILS. 1. EXPLORATORY PITS WERE EXCAVATED WITH A BACKHOE ON OCTOBER 30, 2019. PITS WERE BACKFILLED IMMEDIATELY AFTER EXPLORATORY EXCAVATION OPERATIONS WERE COMPLETED. 2. FREE GOUNDWATER WAS NOT FOUND IN OUR EXPLORATORY PITS AT THE TIME OF EXCAVATION. 3. LOCATIONS OF EXPLORATORY PITS ARE APPROXIMATE. ELEVATIONS WERE ESTIMATED FROM GOOGLE EARTH. 4. THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS AS CONTAINED IN THIS REPORT. Summary Logs of Exploratory Pits FIG. 4 Sample of GRAVEL, SLIGHTLY SILTY (GP -GM) From TP -'I AT 6-7 FEET GRAVEL 77 % SAND 19 % SILT & CLAY 4 % LIQUID LIMIT % PLASTICITY INDEX % i I/YDROMETER ANA LYSIS SIEVE ANALYSIS 25 HR. 7 HR. TIME READINGS U S STANDARD SERIES CLEAR SQUARE OPENINGS 45 MIN. 15 MIN. 60 MIN. 19 MIN. 4 MIN. 1 MIN. '200 '100 50 '40 '30 '16 '10 '0 '4 3/8" 3/4" 1W 3" 5'6" R. 100 90 ����� �_�p�......1- {� IM®MOR I_�-_:pp-- 0 CD °' �' > c o 0 0 0 0 PERCENT RETAINED C1.1 C�MMMC=— 60 10 Eil l _®E{'�MMMM9 070 80 i... 20 (1) "Ci <60 -i z0 M51�""" w y �� <B0 L 050 40 w �E �C_ tY w reMI aqp 50 N z w M,..�I�i SC No M� 60 W Mii 230 30 .. -1-ICC. 10 �--����►� 70 �� ♦Tib' ��m 20 M 0 80 �, --- 001 0 002 .005 .009 .019 ,037 .074 .149 .297042 590 1 19 2 0 2.38 4 76 9 52 19.1 36.1 76.2 12152200 DIAMETER OF PARTICLE IN MILLIMETERS CLAY (PLASTIC) TO SILT (NON -PLASTIC) SANDS GRAVEL FINE MEDIUM COARS , FINE I COARSE COBBLES Sample of GRAVEL, SLIGHTLY SILTY (GP -GM) From TP -'I AT 6-7 FEET GRAVEL 77 % SAND 19 % SILT & CLAY 4 % LIQUID LIMIT % PLASTICITY INDEX % i HYDROMETER ANALYSIS I SIEVE ANALYSIS 1 25 HR. 7 HR. TIME READINGS U.S STANDARD SERIES CLEAR SQUARE OPENINGS 45 MIN. 15 MIN. 60 MIN. 19 MIN 4 MIN 1 MIN. '200 '100 50 '40 '30 16 '10 '8 '4 3/8" 3/4" 1'/," 3" 5"6" 8" 100 0 90 10 80 20 z0 w y __30 <B0 - 40 w reMI 50 N z w SC No 60 W 30 70 20 80 0 .. i'I... .001 0 002 .005 .009 .019 .037 .074 .149 DIAMETER .2970.42 OF PARTICLE .590 .... 1 IN MILLIMETERS 19 2 _ 0 2.38 4 .. ,� 76 9 52 19.1 , 36.1 . ' 76.2 12152200 100 CLAY (PLASTIC) TO SILT (NON -PLASTIC) SANDS GRAVEL FINE 1 MEDIUM I COARS FINE 1 COARSE I COBBLES Sample of GRAVEL, SLIGHTLY SILTY (GP -GM) From TP - 2 AT 4-5 FEET CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION - 84, WEST END PROJECT NO. GS06418,001-125 GRAVEL 73 % SAND SILT & CLAY 4 % LIQUID LIMIT PLASTICITY INDEX Gradation Test Results 23 % FIG. 5 OA TABLE 1 SUMMARY OF LABORATORY TESTING PROJECT NO. GS06418.001-125 EXPLORATORY BORING DEPTH (FEET) MOISTURE CONTENT (%) ATTERBERG LIMITS LIQUID LIMIT (%) PLASTICITY INDEX (%) SOLUBLE SULFATES (%) PERCENT GRAVEL (%) PERCENT SAND (%) PASSING NO. 200 SIEVE (%) DESCRIPTION TP -1 2 14.5 25 5 54 TP -1 CLAY, SILTY, SANDY (CL -ML) 6-7 77 19 4 TP -2 TP -3 4-5 2-3 GRAVEL, SLIGHTLY SILTY (GP) 73 23 4 GRAVEL, SLIGHTLY SILTY (GP) 0.00 CLAY, SILTY, SANDY (CL -ML) Page 1 of 1 APPENDIX A CONSTRUCTION AND PAVEMENT MATERIAL RECOMMENDATIONS CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001.125 Material property recommendations and construction criteria for the pavement alternatives are provided below. These criteria were developed from analysis of the field and laboratory data and our experience. If the materials can- not meet these recommendations, then the pavement design should be reevalu- ated based upon available materials. Materials planned for construction should be submitted and the applicable laboratory tests performed to verify compliance with the specifications. Portland Cement Concrete Pavement (PCCP) 1. Portland cement concrete should have a minimum compressive strength of 4,000 psi at 28 days and a minimum modulus of rupture (flexural strength) of 550 psi in the field. A job mix design is recommended and pe- riodic checks on the iob site should be made to verify compliance with specifications. 2. Portland cement Type I or II can be used in pavements at this site. 3. Portland cement concrete should not be placed when the subgrade or air temperature is below 40°F. 4. Free water should not be finished into the concrete surface and finishers should not use a steel trowel on the surface. Atomizing nozzle pressure sprayers for applying finishing compounds are recommended whenever the concrete surface becomes difficult to finish. 5. Curing of the portland cement concrete should be accomplished by the use of a curing compound. The curing compound should be applied in ac- cordance with manufacturer recommendations. 6. Curing procedures should be implemented, as necessary, to protect the pavement against moisture Toss, rapid temperature change, freezing, and mechanical injury. 7. Construction joints, including longitudinal joints and transverse joints, should be formed during construction or sawed after the concrete has be- gun to set, but prior to uncontrolled cracking. 8. All joints should be properly sealed using a rod back-up and approved sealant. 9. Traffic should not be allowed on the pavement until it has properly cured for 14 days, or 550 psi flexural strength has been attained, with saw joints already cut. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 A-1 i' t 10. Placement of portland cement concrete should be observed and tested by a representative of our firm. Placement should not commence until the subgrade is properly prepared and tested. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-126 A-2 APPENDIX B PAVEMENT MAINTENANCE RECOMMENDATIONS CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS High traffic volumes create pavement rutting and smooth, polished surfaces. Preventive maintenance treatments will typically preserve the original or existing pavement by providing a protective seal and improving skid resistance through a new wearing course. 1. Annual Preventive Maintenance a. Visual pavement evaluations should be performed each spring or fall. b. Reports documenting the progress of distress should be kept current to provide information of effective times to apply preventive mainte- nance. c. Crack sealing should be performed annually as new cracks appear. 2. 4 to 8 Year Preventive Maintenance a. The owner should budget for a preventive treatment at approximate intervals of 4 to 8 years to reduce joint deterioration. b. Typical preventive maintenance for rigid pavements include patching, crack sealing and joint cleaning and sealing. c. Where joint sealants are missing or distressed, resealing is mandato- ry 3. 15 to 20 Year Corrective Maintenance a. Corrective maintenance for rigid pavements includes patching and slab replacement to correct subgrade failures, edge damage and ma- terial failure. b. Asphalt concrete overlays may be required at 15 to 20 -year inter- vals to improve the structural capacity of the pavement. CARBONDALE AND RURAL FIRE PROTECTION DISTRICT STATION 84 - WEST END PROJECT NO. GS06418.001-125 B-1