GEOTECHNICAL EXPLORATION REPORT

Transcription

1 110001_Report_Geotech, 2/ GEOTECHNICAL EXPLORATION REPORT BENSON STREET SEWER REPLACEMENT READING, HAMILTON COUNTY, OHIO MSDGC PROJECT NO PREPARED FOR AECOM 219 MALSBURY ROAD CINCINNATI, OHIO 22 PREPARED BY CTL ENGINEERING, INC. 2 SCHAPPELLE LANE CINCINNATI, OHIO 20 CTL PROJECT NO CIN SEPTEMBER 6, 20

2 110001_Report_Geotech, 3/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page i TABLE OF CONTENTS PAGE I. PROJECT INFORMATION AND PURPOSE... 1 II. SUBSURFACE EXPLORATION... 1 III. FINDINGS... 2 A. Visual Observations...2 B. Geology...2 C. Subsurface Conditions...3 IV. DISCUSSION AND EVALUATION... A. Marginal Subgrade Soils... B. Moderately Plastic Soils... C. Trench Backfill, Compaction and Monitoring... D. Ground Water...6 V. ANALYSIS AND RECOMMENDATIONS... 6 A. Site Preparation and Earthwork Recommendations...6 VI. CHANGED CONDITIONS... VII. TESTING AND OBSERVATION... VIII. CLOSING... APPENDIX A APPENDIX B APPENDIX C TEST BORING RECORDS RESULTS OF SOIL LABORATORY TESTS BORING LOCATION PLAN AND SOIL PROFILE

3 110001_Report_Geotech, / Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 1 I. PROJECT INFORMATION AND PURPOSE In a request for a proposal to CTL Engineering, dated April 19, 20, the Metropolitan Sewer District of Greater Cincinnati (MSDGC) is planning for the design and construction of new sanitary and/or storm sewers to replace approximately, feet of combined sewer in Reading, Ohio. The project consists of the following areas Bradley Street from cul de sac at IR to Jefferson Avenue; Jefferson Avenue from Bradley Street to Maple Street; Maple Street from Jefferson Avenue to Reading Road; Reading Road from Maple Street to Benson Avenue; Benson Street from Reading Road to Hill Street. CTL Engineering, Inc. (CTL Engineering) understands the purpose of this geotechnical exploration is to determine the subsurface conditions of the site in conjunction with evaluating its suitability for the installation of the new sanitary and/or storm sewers and appurtenances. CTL Engineering was provided an AutoCAD drawing prepared by the Metropolitan Sewer District of Greater Cincinnati (MSDGC), undated, showing the existing underground utilities, existing site topographical features, contours, property lines, and proposed sewer profile. II. SUBSURFACE EXPLORATION Four () test borings, designated as B1 through B, were drilled along the alignment of the proposed sanitary sewer. The locations and predetermined depths of the soil test borings were selected by AECOM to provide a general profile of the subsurface conditions at the site. The test borings were located in the field by CTL Engineering personnel utilizing topographic features identified on the plan and profile drawings provided by AECOM. The test borings were drilled on August 1 and 1, 20 utilizing 3.2 inch I.D. hollowstem augers (HSA) powered by an ATVmounted drill rig. Standard Penetration Tests (SPTs) were conducted in the test borings using a pound automatic hammer falling 30 inches to drive a 2inch O.D. split barrel sampler for 1 inches. Standard penetration testing utilizing splitspoon sampling was performed at 2½foot intervals. Soil samples obtained from the drilling operations were preserved in glass jars, visually classified in the field, and delivered to CTL Engineering s soil laboratory for classification, testing and analysis. Drilling, sampling, field and laboratory testing were performed according to standard geotechnical engineering practices and current ASTM procedures. Results from field and

4 110001_Report_Geotech, / Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 2 laboratory tests are shown on the enclosed test boring records in Appendix A. The results of the laboratory tests are presented in Appendix B. III. FINDINGS A. Visual Observations The subject site is located in a residential area, with commercial properties located between B1 and B2. The ground surface elevation generally decreases from west to east. The low elevation point is near the western end of the project area, near B1 at the intersection of Bradley Avenue with Wachendorf Street. The pavement markings, valves, and manholes in the roadway indicate that many underground utilities are present along the proposed sewer alignment. Overhead power lines and overhang from trees are also present along the proposed sewer alignment. Based on available topographic mapping of the site (Cincinnati East Quadrangle, Ohio ½minute Series, USGS, 1961, Revised 191), the topography consists of a slope down from the east end of the sanitary and/or storm sewer alignment to the low point at the western end of the project. Ground surface elevations range from about 60 feet above mean sea level (AMSL) to about 0 feet AMSL, respectively. B. Geology According to the Soil Survey of Hamilton County, Ohio, United States Department of Agriculture in cooperation with Ohio Department of Natural Resources, 199, the surficial soils at the project site are identified as Eldean Urban land complex, 0 to 2 percent slopes (ErA), Urban landrossmoyne complex, 0 to percent slopes (UrB), and Pate silty clay loam, to 1 percent slopes (PfC). The ErA soils are mapped in the area of the sewer along Bradley Street, Jefferson Avenue, and Maple Street from Jefferson Avenue to Jenny Lind Street. The UrB soils are mapped in the area along Maple Street from Jenny Lind Street to Reading Road, Reading Road, and Benson Street from Reading Road to th Street. The PfC soils are mapped in the area along Benson Street from th Street to Hill Street. These mapped soils are described as well drained. Mapping of the bedrock topography (Bedrock Topography of the Cincinnati East, Ohio Quadrangle, OpenFile Map BT3B, ODNR Geological Survey, 199) indicates the elevation of the top of rock surface in the immediate project area is between about feet and 600 feet AMSL. These elevations correlate to approximate depths, ranging from 0 feet to 1 feet bgs, to the top of rock surface. It should be noted that the referenced mapping utilizes 0foot contours

5 110001_Report_Geotech, 6/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 3 that are interpolated from topographic surface features and widely spaced data points where water wells and soil borings have encountered rock. According to the mapping of bedrock geology in the area, (Reconnaissance Bedrock Geology of the Cincinnati East, Ohio Quadrangle, OpenFile Map BG2, ODNR Geological Survey, February 2002) the surficial soil deposits are underlain by Ordovicianage sedimentary rock. Specifically, the bedrock underlying the site is identified as the Kope Formation. This formation consists of shale with approximately 2 percent interbedded limestone. The rock is described as gray to bluish gray and weathers light gray to yellowish gray, with thin to thick bedding which is planar. According to the mapping of karst features in the area (Known and Probable Karst in Ohio, Map EG1, Revised September 2002, ODNR Geological Survey), the project area is not located in or near a probable karst area or an area of carbonatedominant lithology. C. Subsurface Conditions Further details of the subsurface conditions encountered during CTL Engineering s geotechnical exploration are presented on the test boring records in Appendix A. 1. Surficial Materials All test borings encountered pavement materials at the ground surface. The pavement consisted of asphalt ranging in thickness from to inches. Below the asphalt, test boring B1 encountered concrete with a thickness inches. Test boring B encountered 6 inches of gravel base below the asphalt. 2. FineGrained Soils Finegrained (silt and clay) soils, classified as CL (lean clay) or ML (silt) according to the USCS, were encountered in all of the test borings. The lean clay materials were described as brown or gray soft to very stiff sandy lean clay, lean clay with gravel, lean clay with sand, or lean clay. The silt materials were described as brown or gray stiff sandy silt or silt with sand. Within these cohesive materials, SPT Nvalues ranging from to 26 blows per foot (bpf) were determined in the test borings. CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near these moderately to nonplastic soils as identified in borings B1, B3 and B. Samples of the materials were tested in the laboratory for moisture content, Atterberg Limits, and/or particle size analysis. The results of these tests are

6 110001_Report_Geotech, / Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page presented in Appendix B and are summarized here. The natural moisture content of the cohesive soils ranged from to 2 percent. Representative samples of the lean clay materials had Liquid Limits (LL) ranging from 2 to 39 and Plasticity Indices (PI) ranging from 9 to 1. A representative sample of the silt material was tested and found to be non plastic. 3. Granular Soils Granular (sand and gravel) soils were encountered in all test borings except B. These soils were classified as SC (clayey sand), SM (silty sand), SW (wellgraded sand), SP (poorlygraded sand), GW (wellgraded gravel), according to the USCS. Within the granular materials, SPT Nvalues ranged from to 30 blows per foot (bpf). CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near or on these granular soils in the area of boring B2. Samples of these soils were tested in the laboratory for moisture content, Atterberg Limits, and/or particle size analysis. The results of these tests are presented in Appendix B and are summarized here. The natural moisture content of the granular soils ranged from 3 to 1 percent. A representative sample of an SM (silty sand) material was tested and found to be non plastic.. Weathered Rock In test boring B0 highly weathered shale was encountered at a depth ranging from about 26 feet bgs (elevation 626 feet). This material is derived from the underlying unweathered sedimentary rock and may appear soillike depending on the degree of weathering. The degree of weathering is typically associated with the color; for example brown (severely weathered) to olive brown or gray, to gray (slightly or unweathered); the moisture content (decrease in moisture content with decreased weathering); degree of toughness (weak to strong). The recovered samples of the highly weathered rock material were visually described as gray. Standard Penetration Tests conducted in the severely weathered shale resulted in values of 0+ blows within the initial 6 inch interval (split spoon refusal).. Ground Water The depth to groundwater was recorded during drilling and after removing augers at the completion of drilling, prior to backfilling of the borehole. The borings were immediately backfilled due to safety and traffic requirements and therefore longterm water level readings were not obtained. It should be noted that the greater Cincinnati area has been in a drought condition at the time of this exploration and the presence of ground water or its level may be not be representative of normal ground water conditions. Groundwater was encountered only in test boring B1. During drilling, groundwater was encountered at 11.0 feet bgs, and at the completion of drilling,

7 110001_Report_Geotech, / Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page groundwater was encountered at.0 feet bgs. These depths are associated with elevations 31.0 and 32.0 feet. IV. DISCUSSION AND EVALUATION Based on the subsurface information collected from the test borings, CTL Engineering s evaluation is that the site is generally suitable for the installation of the proposed sanitary sewers. However, conditions were encountered which pose a concern from a geotechnical and construction standpoint. These concerns and their implications are addressed below. A. Marginal Subgrade Soils Weak soils with SPT Nvalues of less than bpf or lower are anticipated above and/or near the elevation of the proposed sewers along the entire alignment. The natural moisture contents of these materials are on the wet of the soil type s optimum moisture content. These soils are classified as OSHA Soil Type B or C, and appropriate cautions should be taken during trench excavation to limit the time the trench is left open. B. Moderately Plastic Soils Moderately plastic soils classified as CL (lean clay) according to the USCS were encountered in the test borings at the site. CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near or on the moderately plastic soils in some portions of the proposed sewers. These moderately plastic soils are susceptible to volume change with variations in moisture content. Should these volume changes (due to wetting during construction occur near the new sewers, the resulting deformations can cause undesirable vertical movement. Construction planning should minimize exposure of these soils to excessive wetting or drying. It is anticipated that once construction is complete the soil moisture content at the proposed sewer depth will stabilize; assuming sewer exfiltration is controlled satisfactorily. C. Trench Backfill, Compaction and Monitoring Monitoring of earthwork operations, especially the placement of backfill and compaction operations will be critical to the successful performance of the sanitary sewers and also the overlying roadway pavement after construction. Installation of the sewers will require the placement and compaction of a significant volume of granular backfill. The placement of large volumes of fill can lead to excessive settlement during and after construction if not properly placed and compacted.

8 110001_Report_Geotech, 9/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 6 The use of flowable controlled density fill (CDF) as a backfill material may be preferred in areas where sewer trenches are deep, the sewer trench width is limited due to other utility conflicts, or the sewer trench is located within drives and roadways where traffic needs to be reestablished within the same day. D. Ground Water The groundwater encountered was observed within a cohesive layer identified in test boring B1. Based on our experience with the geology at this site, ground water conditions affecting construction projects are related to trapped or perched water that may occur in irregular, discontinuous zones within the soil overburden, and may also be present but were not identified on the test boring records. Typically water bearing strata are associated with granular layers such as sand and gravel materials. When these water bearing strata are exposed in excavations, such as utility trenches, they can produce widely varying seepage durations and rates depending on recent rainfall activity and other hydrogeologic characteristics of the area. Therefore, the presence of ground water and the levels at which it is encountered may vary from those measured at the time of drilling. These perched water sources are often not linked to the more continuous static groundwater encountered at greater depths. V. ANALYSIS AND RECOMMENDATIONS Based upon the preceding considerations as well as the subsurface information obtained from the field and laboratory testing, the following recommendations are provided. A. Site Preparation and Earthwork Recommendations 1. CTL Engineering anticipates that existing soils at the site can be excavated using conventional excavation equipment. 2. Water should be prevented from ponding in the trench excavation during construction. Absorption of heavy rainfall and accumulations of water may result in a volume change of the soil along with severe reduction of strength. The Geotechnical Engineer should be contacted if the soil becomes excessively wet, dry, or frozen. 3. Temporary trench excavations in excess of.0 feet in depth should be sloped or shored in accordance with OSHA regulations. The following provides recommendations in accordance with OSHA requirements based on the encountered soil types.

9 110001_Report_Geotech, / Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page The cohesive soils and granular soils encountered in the test borings are classified as Soil Type B and C, respectively. In excavations that are 20 feet or less in depth, OSHA regulations allow 11 slopes in Type B soils, and 1.1 slopes in Type C soils. At the maximum sewer depth of approximately 13 feet, the width of the excavation slopes should be 26 feet in Type B soils and 39 feet in Type C soils at a minimum, not including the width of the trench between the slopes.. Due to the presence of utilities throughout the project area and the need to minimize the impact of the construction on traffic, CTL Engineering recommends that vertical trench walls be utilized along with a support or shield system as specified in OSHA Standard 1926 Subpart P App B.. Dewatering of the trench excavation during construction of the sewer should be anticipated within the entire granular layers. It is anticipated that dewatering utilizing a pump and sump method should achieve dewatering to the levels that will allow for construction of the sewers. However, this will be dependent upon the construction schedule (period of sewer construction) and recent precipitation rates. During the wet periods of the year, typically from October through May, groundwater levels and infiltration rates will substantially increase and may require continuous pumping or more extensive dewatering methods. The contractor should be made explicitly aware of the potential for this condition in the prebid meeting and allow for this in his contract or a contingency should be made by the owner for additional dewatering requirements beyond those normally budgeted for similar construction. VI. CHANGED CONDITIONS The evaluations, conclusions, and recommendations in this report are based on our interpretation of the field and laboratory data obtained during the exploration, our understanding of the project and our experience with similar sites and subsurface conditions using generally accepted geotechnical engineering practices. Although individual test borings are representative of the subsurface conditions at the boring locations on the dates drilled, they are not necessarily representative of the subsurface conditions between boring locations or subsurface conditions during other seasons of the year. In the event that changes in the project are proposed, additional information becomes available, or if it is apparent that subsurface conditions are different from those provided in this report, CTL Engineering should be notified so that our recommendations can be modified, if required.

10 110001_Report_Geotech, 11/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page VII. TESTING AND OBSERVATION During the design process, it is recommended that CTL Engineering work with the project designers to confirm that the geotechnical recommendations are properly incorporated into the final plans and specifications, and to assist with establishing criteria for the construction observation and testing. CTL Engineering is not responsible for independent conclusions, opinions and recommendations made by others based on the data and recommendations provided in this report. It is recommended that CTL Engineering be retained to provide construction quality control services on this project. If CTL Engineering is not retained for these services, CTL Engineering shall assume no responsibility for compliance with the design concepts or recommendations provided. VIII. CLOSING This report has been prepared for the exclusive use by AECOM for use only on this project. Our services have been performed in accordance with generally accepted Geotechnical Engineering principles and practices. No warranty is either expressed or implied. This report addresses only the geotechnical aspects of this project and does not include any environmental issues. Specific design and construction recommendations have been provided in this report. Therefore, the report should be used in its entirety. Respectfully Submitted, CTL ENGINEERING, INC. Nathan Wilhelm, E.I. Project Engineer Doug R. Batt, P.E. Project Engineer License Ohio E CIN_MSDGC_Benson Street_Geo Rpt_ Docx

11 110001_Report_Geotech, / APPENDIX A TEST BORING RECORDS

12 110001_Report_Geotech, 13/ "A" LINE GRAPH 60 PLASTICITY INDEX 0 CH or OH 0 CL or OL MH or OH CLML MLorOL LIQUID LIMIT

13 110001_Report_Geotech, 1/ SOIL DESCRIPTION NONCOHESIVE SOIL DESCRIPTION STANDARD PENETRATION BLOWCOUNTS PER FOOT (BPF) Very Loose...0 Loose... Medium Dense Dense Very Dense... Over 0 COHESIVE SOIL DESCRIPTION STANDARD PENETRATION BLOWCOUNTS PER FOOT (BPF) Very Soft Soft...2 Medium Stiff... Stiff Very Stiff Hard... Over 30 GRADATION COMPONENT SIZE Boulders...Larger than " Cobbles... " 3" Gravel...Passing 3" Retained on # Sand... Passing # Retained on #200 Silt mm to 0.00 mm Clay... Smaller than 0.00 mm COMPONENT MODIFIERS SIZE Traces... 0 % Little % Some % And % MOISTURE TERMS DESCRIPTION Dry...Powdery Damp...Below Plastic Moist...Above Plastic Limit & Below Liquid Limit Wet...Above Liquid Limit

14 BORING ELEVATION STATION OFFSET TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO. 2.0 Feet BORING METHOD HSA N/A N/A 2.0 Feet RIG TYPE CASING DIA. CORE SIZE CME 3.2 Inches I.D. N/A _Report_Geotech, 1/ PROJECT Benson St. Sewer MSDGC SHEET 1 OF 2 LOCATION City of Reading, Ohio DATE STARTED 01 PROJECT NO CIN DATE COMPLETED 01 GROUNDWATER Encountered at 11.0' At completion.0' Caved in at.0' B01 HAMMER DRILLER TEMPERATURE WEATHER Auto BK Sunny STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION Asphalt (") Concrete (") Stiff, Brown, SANDY SILT (ML), Moist STRATUM SAMPLE NUMBER SS1 SPT per 6" 6 BLOWS per " (N) 11 % RECOVERY 6 MOISTURE CONTENT 11 TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf.0* ATTERBERG LIMITS LL PL PI 3. Loose, Brown, POORLY GRADED SAND (SP), Moist 3. SS2 9 6 TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ Loose to Medium Dense, Brown, WELL GRADED GRAVEL WITH SAND (GW), Moist Medium Stiff, Brown, SANDY LEAN CLAY(CL), Moist Stiff, Gray, SANDY LEAN CLAY(CL), Moist Loose, Gray, WELL GRADED SAND (SP), Moist Very Stiff, Gray, LEAN CLAY WITH GRAVEL (CL), Moist Continued on next page CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH SS3 SS SS SS6 SS SS BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR 9.0*.0* 9.0* ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

15 TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO _Report_Geotech, 16/ PROJECT Benson St. Sewer MSDGC SHEET 2 OF 2 B01 STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION STRATUM SAMPLE NUMBER SPT per 6" BLOWS per " (N) % RECOVERY MOISTURE CONTENT TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf ATTERBERG LIMITS LL PL PI SS Medium Dense, Brown, WELL GRADED GRAVEL WITH SAND (GW), Moist BOTTOM OF 2.0 FEET 2.0 SS TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 3 0 CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

16 BORING ELEVATION STATION OFFSET TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO..0 Feet BORING METHOD HSA N/A N/A 2.0 Feet RIG TYPE CASING DIA. CORE SIZE CME 3.2 Inches I.D. N/A _Report_Geotech, 1/ PROJECT Benson St. Sewer MSDGC SHEET 1 OF 2 LOCATION City of Reading, Ohio DATE STARTED 01 PROJECT NO CIN DATE COMPLETED 01 GROUNDWATER Encountered at Not Encountered Caved in at 1.0' B02 HAMMER DRILLER TEMPERATURE WEATHER Auto BK Sunny STRATUM ELEVATION. SAMPLE SOIL/MATERIAL DESCRIPTION Asphalt (6") STRATUM 0. SAMPLE NUMBER SPT per 6" BLOWS per " (N) % RECOVERY MOISTURE CONTENT TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf ATTERBERG LIMITS LL PL PI 2.0 Soft, Brown, LEAN CLAY WITH SAND (CL), Damp 3.0 SS * Medium Stiff, Brown, SANDY LEAN CLAY (CL), Moist SS2 1.0* TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ Stiff, Light Brown, SANDY SILT (ML), Moist Medium Dense, Brown, CLAYEY SAND WITH GRAVEL (SC), Damp to Moist Very Stiff, Gray, SANDY LEAN CLAY (CL), Damp Continued on next page CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH SS3 SS SS SS6 SS SS BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR 1.0* 0.0* 0.0* 0.0*.0*.0* NP NP ABBREVIATIONS NP Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

17 TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO _Report_Geotech, 1/ PROJECT Benson St. Sewer MSDGC SHEET 2 OF 2 B02 STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION STRATUM SAMPLE NUMBER SPT per 6" BLOWS per " (N) % RECOVERY MOISTURE CONTENT TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf ATTERBERG LIMITS LL PL PI 22.0 Very Stiff, Gray, SANDY LEAN CLAY (CL), Damp 23.0 SS * Very Stiff, Brown, SILTY SAND (SM), Moist 2.0 SS * NP NP NP BOTTOM OF 2.0 FEET 30 TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 3 0 CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

18 BORING ELEVATION STATION OFFSET TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO..0 Feet BORING METHOD HSA N/A N/A 2.0 Feet RIG TYPE CASING DIA. CORE SIZE CME 3.2 Inches I.D. N/A _Report_Geotech, 19/ PROJECT Benson St. Sewer MSDGC SHEET 1 OF 2 LOCATION City of Reading, Ohio DATE STARTED 01 PROJECT NO CIN DATE COMPLETED 01 GROUNDWATER Encountered at Not Encountered Caved in at.0' B03 HAMMER DRILLER TEMPERATURE WEATHER Auto BK Sunny STRATUM ELEVATION.3 SAMPLE Asphalt (") SOIL/MATERIAL DESCRIPTION STRATUM 0. SAMPLE NUMBER SPT per 6" BLOWS per " (N) % RECOVERY MOISTURE CONTENT TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf ATTERBERG LIMITS LL PL PI.0 Stiff, Brown, LEAN CLAY WITH SAND (CL), Moist 3.0 SS * TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ Very Loose, Brown, WELL GRADED SAND (SW), Damp Medium Stiff, Gray, LEAN CLAY WITH SAND (CL), Moist Stiff, Gray, SILT WITH SAND (ML), Wet Medium to Very Stiff, Gray, SANDY LEAN CLAY (CL), Damp Continued on next page CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH SS2 SS3 SS SS SS6 SS SS BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR.0* 1.0* 2.0* 3.0*.0* ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

19 TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO _Report_Geotech, 20/ PROJECT Benson St. Sewer MSDGC SHEET 2 OF 2 B03 STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION STRATUM SAMPLE NUMBER SPT per 6" BLOWS per " (N) % RECOVERY MOISTURE CONTENT TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf ATTERBERG LIMITS LL PL PI SS * Medium to Very Stiff, Gray, SANDY LEAN CLAY (CL), Damp 2.0 SS * BOTTOM OF 2.0 FEET 30 TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 3 0 CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

20 BORING ELEVATION STATION OFFSET TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO. 6.0 Feet BORING METHOD HSA N/A N/A 2.0 Feet RIG TYPE CASING DIA. CORE SIZE CME 3.2 Inches I.D. N/A _Report_Geotech, 21/ PROJECT Benson St. Sewer MSDGC SHEET 1 OF 2 LOCATION City of Reading, Ohio DATE STARTED 01 PROJECT NO CIN DATE COMPLETED 01 GROUNDWATER Encountered at Not Encountered Caved in at.' B0 HAMMER DRILLER TEMPERATURE WEATHER Auto BK Sunny STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION Asphalt (6") Granular Base (6") Medium Stiff, Brown, LEAN CLAY WITH SAND (CL), Damp STRATUM SAMPLE NUMBER SS1 SPT per 6" BLOWS per " (N) % RECOVERY 33 MOISTURE CONTENT 1 TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf 6.0* ATTERBERG LIMITS LL PL PI SS2 22.0* TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ Medium Stiff, Brown and Gray, LEAN CLAY (CL), Moist Very Stiff to Hard, Brown, LEAN CLAY (CL), FEET LIMESTONE COBBLES ENCOUNTERED Continued on next page CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20. SS3 SS SS SS6 SS SS BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger /3 0/3 SS ST CR BS WH /3 0/ SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR.0*.0* 9.0* 9.0* ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

21 TEST BORING RECORD CLIENT AECOM Technical Services, Inc. BORING NO _Report_Geotech, 22/ PROJECT Benson St. Sewer MSDGC SHEET 2 OF 2 B0 STRATUM ELEVATION SAMPLE SOIL/MATERIAL DESCRIPTION STRATUM 21.0 SAMPLE NUMBER SS9 SPT per 6" 3 0/2 BLOWS per " (N) 0/2 % RECOVERY MOISTURE CONTENT 13 TOTAL UNIT WEIGHT pcf UNCONF. COMP., ksf 9.0* ATTERBERG LIMITS LL PL PI Very Weak, Gray, SEVERELY WEATHERED SHALE, Damp SS 0/3 0/ BOTTOM OF 2.0 FEET 30 TEST BORING/PIT RECORD CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 3 0 CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 BORING METHOD HSA Hollow Stem Auger SFA Solid Flight Auger RC Rock Coring MD Mud Drilling WD Wash Drilling HA Hand Auger SS ST CR BS WH SAMPLING METHOD Split Spoon Sample Shelby Tube Sample Rock Core Sample Bag Sample Weight Of Hammer * LL PL PI SPT SSR ABBREVIATIONS Hand Penetrometer Liquid Limit Plastic Limit Plasticity Index Standard Penetration Test Split Spoon Refusal

22 110001_Report_Geotech, 23/ APPENDIX B RESULTS OF SOIL LABORATORY TESTS

23 PERCENT FINER BY WEIGHT U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 2 1 1/ / 3/ _Report_Geotech, 2/ HYDROMETER USCS SIEVE GRAPH CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 1 0 COBBLES Specimen ID Specimen ID Sample B02 SS Sample coarse GRAVEL D 19 fine D CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 Telephone Fax GRAIN SIZE IN MILLIMETERS coarse D0 0.0 medium SAND Classification D fine SANDY SILT (ML) nonplastic silt, fine sand D %Gravel SILT OR CLAY %Sand 33 LL NP %MC 13 PL NP %Silt GRAIN SIZE DISTRIBUTION Project Benson St. Sewer MSDGC Location City of Reading, Ohio CTL Project Number 00032CIN PI NP Cu. Cc 1.62 %Clay

24 PERCENT FINER BY WEIGHT U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 2 1 1/ / 3/ _Report_Geotech, 2/ HYDROMETER USCS SIEVE GRAPH CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 1 0 COBBLES Specimen ID Specimen ID Sample B02 SS Sample coarse GRAVEL D 9.2 fine D CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 Telephone Fax GRAIN SIZE IN MILLIMETERS coarse D0 0.1 medium SAND Classification D fine SILTY SAND (SM) fine sand, nonplastic silt D %Gravel SILT OR CLAY %Sand 6 LL NP %MC 1 PL NP %Silt 26 GRAIN SIZE DISTRIBUTION Project Benson St. Sewer MSDGC Location City of Reading, Ohio CTL Project Number 00032CIN PI NP Cu 30. Cc 3. %Clay

25 PERCENT FINER BY WEIGHT U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 2 1 1/ / 3/ _Report_Geotech, 26/ HYDROMETER USCS SIEVE GRAPH CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 1 0 COBBLES Specimen ID Specimen ID Sample B03 SS9 Sample coarse GRAVEL D 9.2 fine D CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 Telephone Fax GRAIN SIZE IN MILLIMETERS coarse D medium SAND D fine D 0.1 %Gravel 0.01 SILT OR CLAY Classification LL PL SANDY LEAN CLAY (CL) 2 16 low plasticity clay, fine to medium sand %MC 13 %Sand 2 %Silt GRAIN SIZE DISTRIBUTION Project Benson St. Sewer MSDGC Location City of Reading, Ohio CTL Project Number 00032CIN PI Cu Cc %Clay 2

26 PERCENT FINER BY WEIGHT U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS 2 1 1/ / 3/ _Report_Geotech, 2/ HYDROMETER USCS SIEVE GRAPH CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ 1 0 COBBLES Specimen ID Specimen ID Sample B0 SS Sample coarse GRAVEL D 9.2 fine D CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, OH 20 Telephone Fax GRAIN SIZE IN MILLIMETERS coarse D medium SAND D30 fine D 0.1 %Gravel SILT OR CLAY Classification LL PL LEAN CLAY (CL) moderate plasticity clay %MC 21 %Sand %Silt 6 GRAIN SIZE DISTRIBUTION Project Benson St. Sewer MSDGC Location City of Reading, Ohio CTL Project Number 00032CIN PI Cu Cc %Clay

27 110001_Report_Geotech, 2/ APPENDIX B BORING LOCATION PLAN AND SOIL PROFILE

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32 110001_Report_Geotech, 33/ 60 B /3 0/3 0/2 0/ CTL FENCE 11X1 TEST CTL CORPORATE.GDT ASTM LIBRARY BY DM 6230 (TESTING).GLB 00032CIN.GPJ /30/ Elevation (ft) B LEGEND Standard Penetration in Ground water encountered USCS Poorlygraded USCS Wellgraded # Asphalt Blows per Foot (Nvalue) at the time of drilling Sand Sand /30/20 Benson St. Sewer MSDGC w Moisture Content in percent (w) Boring cavein location B02 Ground water encountered at the completion of drilling LITHOLOGY Concrete USCS Silt B USCS Wellgraded Gravel USCS Low Plasticity Clay (CL) USCS Clayey Sand USCS Silty Sand (SM) DATE SCALE As Shown DRAWN BY JW SOIL PROFILE REVIEWED BY DRB City of Reading, Ohio SHEET CTL Project Number 00032CIN

33 110001_Report_Geotech, 3/ CTL Engineering, Inc. 2 Schappelle Lane Cincinnati, Ohio 20 Phone 13/2266 Fax 13/3660 AN EMPLOYEE OWNED COMPANY Consulting Engineers Testing Inspection Services Analytical Laboratories Established 192 September 6, 20 AECOM 219 Malsbury Road Cincinnati, Ohio 22 Attention Reference Mr. Shawn Loew, P.E. Project Manager Geotechnical Exploration Report Benson Street Sewer Replacement Reading, Hamilton County, Ohio CTL Engineering Project No. 0003CIN Dear Mr. Loew CTL Engineering, Inc. has completed the geotechnical exploration report for the above referenced project. One electronic copy (PDF file) of the geotechnical exploration report has been provided. Thank you for the opportunity to be of service to you on this project. If you have any questions, please contact our office. Respectfully Submitted, CTL ENGINEERING, INC. Doug R. Batt, P.E. Project Manager

34 110001_Report_Geotech, 3/ GEOTECHNICAL EXPLORATION REPORT BENSON STREET SEWER REPLACEMENT READING, HAMILTON COUNTY, OHIO MSDGC PROJECT NO PREPARED FOR AECOM 219 MALSBURY ROAD CINCINNATI, OHIO 22 PREPARED BY CTL ENGINEERING, INC. 2 SCHAPPELLE LANE CINCINNATI, OHIO 20 CTL PROJECT NO CIN SEPTEMBER 6, 20

35 110001_Report_Geotech, 36/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page i TABLE OF CONTENTS PAGE I. PROJECT INFORMATION AND PURPOSE... 1 II. SUBSURFACE EXPLORATION... 1 III. FINDINGS... 2 A. Visual Observations...2 B. Geology...2 C. Subsurface Conditions...3 IV. DISCUSSION AND EVALUATION... A. Marginal Subgrade Soils... B. Moderately Plastic Soils... C. Trench Backfill, Compaction and Monitoring... D. Ground Water...6 V. ANALYSIS AND RECOMMENDATIONS... 6 A. Site Preparation and Earthwork Recommendations...6 VI. CHANGED CONDITIONS... VII. TESTING AND OBSERVATION... VIII. CLOSING... APPENDIX A APPENDIX B APPENDIX C TEST BORING RECORDS RESULTS OF SOIL LABORATORY TESTS BORING LOCATION PLAN AND SOIL PROFILE

36 110001_Report_Geotech, 3/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 1 I. PROJECT INFORMATION AND PURPOSE In a request for a proposal to CTL Engineering, dated April 19, 20, the Metropolitan Sewer District of Greater Cincinnati (MSDGC) is planning for the design and construction of new sanitary and/or storm sewers to replace approximately, feet of combined sewer in Reading, Ohio. The project consists of the following areas Bradley Street from cul de sac at IR to Jefferson Avenue; Jefferson Avenue from Bradley Street to Maple Street; Maple Street from Jefferson Avenue to Reading Road; Reading Road from Maple Street to Benson Avenue; Benson Street from Reading Road to Hill Street. CTL Engineering, Inc. (CTL Engineering) understands the purpose of this geotechnical exploration is to determine the subsurface conditions of the site in conjunction with evaluating its suitability for the installation of the new sanitary and/or storm sewers and appurtenances. CTL Engineering was provided an AutoCAD drawing prepared by the Metropolitan Sewer District of Greater Cincinnati (MSDGC), undated, showing the existing underground utilities, existing site topographical features, contours, property lines, and proposed sewer profile. II. SUBSURFACE EXPLORATION Four () test borings, designated as B1 through B, were drilled along the alignment of the proposed sanitary sewer. The locations and predetermined depths of the soil test borings were selected by AECOM to provide a general profile of the subsurface conditions at the site. The test borings were located in the field by CTL Engineering personnel utilizing topographic features identified on the plan and profile drawings provided by AECOM. The test borings were drilled on August 1 and 1, 20 utilizing 3.2 inch I.D. hollowstem augers (HSA) powered by an ATVmounted drill rig. Standard Penetration Tests (SPTs) were conducted in the test borings using a pound automatic hammer falling 30 inches to drive a 2inch O.D. split barrel sampler for 1 inches. Standard penetration testing utilizing splitspoon sampling was performed at 2½foot intervals. Soil samples obtained from the drilling operations were preserved in glass jars, visually classified in the field, and delivered to CTL Engineering s soil laboratory for classification, testing and analysis. Drilling, sampling, field and laboratory testing were performed according to standard geotechnical engineering practices and current ASTM procedures. Results from field and

37 110001_Report_Geotech, 3/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 2 laboratory tests are shown on the enclosed test boring records in Appendix A. The results of the laboratory tests are presented in Appendix B. III. FINDINGS A. Visual Observations The subject site is located in a residential area, with commercial properties located between B1 and B2. The ground surface elevation generally decreases from west to east. The low elevation point is near the western end of the project area, near B1 at the intersection of Bradley Avenue with Wachendorf Street. The pavement markings, valves, and manholes in the roadway indicate that many underground utilities are present along the proposed sewer alignment. Overhead power lines and overhang from trees are also present along the proposed sewer alignment. Based on available topographic mapping of the site (Cincinnati East Quadrangle, Ohio ½minute Series, USGS, 1961, Revised 191), the topography consists of a slope down from the east end of the sanitary and/or storm sewer alignment to the low point at the western end of the project. Ground surface elevations range from about 60 feet above mean sea level (AMSL) to about 0 feet AMSL, respectively. B. Geology According to the Soil Survey of Hamilton County, Ohio, United States Department of Agriculture in cooperation with Ohio Department of Natural Resources, 199, the surficial soils at the project site are identified as Eldean Urban land complex, 0 to 2 percent slopes (ErA), Urban landrossmoyne complex, 0 to percent slopes (UrB), and Pate silty clay loam, to 1 percent slopes (PfC). The ErA soils are mapped in the area of the sewer along Bradley Street, Jefferson Avenue, and Maple Street from Jefferson Avenue to Jenny Lind Street. The UrB soils are mapped in the area along Maple Street from Jenny Lind Street to Reading Road, Reading Road, and Benson Street from Reading Road to th Street. The PfC soils are mapped in the area along Benson Street from th Street to Hill Street. These mapped soils are described as well drained. Mapping of the bedrock topography (Bedrock Topography of the Cincinnati East, Ohio Quadrangle, OpenFile Map BT3B, ODNR Geological Survey, 199) indicates the elevation of the top of rock surface in the immediate project area is between about feet and 600 feet AMSL. These elevations correlate to approximate depths, ranging from 0 feet to 1 feet bgs, to the top of rock surface. It should be noted that the referenced mapping utilizes 0foot contours

38 110001_Report_Geotech, 39/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page 3 that are interpolated from topographic surface features and widely spaced data points where water wells and soil borings have encountered rock. According to the mapping of bedrock geology in the area, (Reconnaissance Bedrock Geology of the Cincinnati East, Ohio Quadrangle, OpenFile Map BG2, ODNR Geological Survey, February 2002) the surficial soil deposits are underlain by Ordovicianage sedimentary rock. Specifically, the bedrock underlying the site is identified as the Kope Formation. This formation consists of shale with approximately 2 percent interbedded limestone. The rock is described as gray to bluish gray and weathers light gray to yellowish gray, with thin to thick bedding which is planar. According to the mapping of karst features in the area (Known and Probable Karst in Ohio, Map EG1, Revised September 2002, ODNR Geological Survey), the project area is not located in or near a probable karst area or an area of carbonatedominant lithology. C. Subsurface Conditions Further details of the subsurface conditions encountered during CTL Engineering s geotechnical exploration are presented on the test boring records in Appendix A. 1. Surficial Materials All test borings encountered pavement materials at the ground surface. The pavement consisted of asphalt ranging in thickness from to inches. Below the asphalt, test boring B1 encountered concrete with a thickness inches. Test boring B encountered 6 inches of gravel base below the asphalt. 2. FineGrained Soils Finegrained (silt and clay) soils, classified as CL (lean clay) or ML (silt) according to the USCS, were encountered in all of the test borings. The lean clay materials were described as brown or gray soft to very stiff sandy lean clay, lean clay with gravel, lean clay with sand, or lean clay. The silt materials were described as brown or gray stiff sandy silt or silt with sand. Within these cohesive materials, SPT Nvalues ranging from to 26 blows per foot (bpf) were determined in the test borings. CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near these moderately to nonplastic soils as identified in borings B1, B3 and B. Samples of the materials were tested in the laboratory for moisture content, Atterberg Limits, and/or particle size analysis. The results of these tests are

39 110001_Report_Geotech, 0/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page presented in Appendix B and are summarized here. The natural moisture content of the cohesive soils ranged from to 2 percent. Representative samples of the lean clay materials had Liquid Limits (LL) ranging from 2 to 39 and Plasticity Indices (PI) ranging from 9 to 1. A representative sample of the silt material was tested and found to be non plastic. 3. Granular Soils Granular (sand and gravel) soils were encountered in all test borings except B. These soils were classified as SC (clayey sand), SM (silty sand), SW (wellgraded sand), SP (poorlygraded sand), GW (wellgraded gravel), according to the USCS. Within the granular materials, SPT Nvalues ranged from to 30 blows per foot (bpf). CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near or on these granular soils in the area of boring B2. Samples of these soils were tested in the laboratory for moisture content, Atterberg Limits, and/or particle size analysis. The results of these tests are presented in Appendix B and are summarized here. The natural moisture content of the granular soils ranged from 3 to 1 percent. A representative sample of an SM (silty sand) material was tested and found to be non plastic.. Weathered Rock In test boring B0 highly weathered shale was encountered at a depth ranging from about 26 feet bgs (elevation 626 feet). This material is derived from the underlying unweathered sedimentary rock and may appear soillike depending on the degree of weathering. The degree of weathering is typically associated with the color; for example brown (severely weathered) to olive brown or gray, to gray (slightly or unweathered); the moisture content (decrease in moisture content with decreased weathering); degree of toughness (weak to strong). The recovered samples of the highly weathered rock material were visually described as gray. Standard Penetration Tests conducted in the severely weathered shale resulted in values of 0+ blows within the initial 6 inch interval (split spoon refusal).. Ground Water The depth to groundwater was recorded during drilling and after removing augers at the completion of drilling, prior to backfilling of the borehole. The borings were immediately backfilled due to safety and traffic requirements and therefore longterm water level readings were not obtained. It should be noted that the greater Cincinnati area has been in a drought condition at the time of this exploration and the presence of ground water or its level may be not be representative of normal ground water conditions. Groundwater was encountered only in test boring B1. During drilling, groundwater was encountered at 11.0 feet bgs, and at the completion of drilling,

40 110001_Report_Geotech, 1/ Geotechnical Exploration Report September 6, 20 Benson Street Sewer Replacement; MSDGC Project No CTL Project No CIN Reading, Hamilton County, Ohio Page groundwater was encountered at.0 feet bgs. These depths are associated with elevations 31.0 and 32.0 feet. IV. DISCUSSION AND EVALUATION Based on the subsurface information collected from the test borings, CTL Engineering s evaluation is that the site is generally suitable for the installation of the proposed sanitary sewers. However, conditions were encountered which pose a concern from a geotechnical and construction standpoint. These concerns and their implications are addressed below. A. Marginal Subgrade Soils Weak soils with SPT Nvalues of less than bpf or lower are anticipated above and/or near the elevation of the proposed sewers along the entire alignment. The natural moisture contents of these materials are on the wet of the soil type s optimum moisture content. These soils are classified as OSHA Soil Type B or C, and appropriate cautions should be taken during trench excavation to limit the time the trench is left open. B. Moderately Plastic Soils Moderately plastic soils classified as CL (lean clay) according to the USCS were encountered in the test borings at the site. CTL Engineering anticipates that the sanitary and/or storm sewer bedding will bear near or on the moderately plastic soils in some portions of the proposed sewers. These moderately plastic soils are susceptible to volume change with variations in moisture content. Should these volume changes (due to wetting during construction occur near the new sewers, the resulting deformations can cause undesirable vertical movement. Construction planning should minimize exposure of these soils to excessive wetting or drying. It is anticipated that once construction is complete the soil moisture content at the proposed sewer depth will stabilize; assuming sewer exfiltration is controlled satisfactorily. C. Trench Backfill, Compaction and Monitoring Monitoring of earthwork operations, especially the placement of backfill and compaction operations will be critical to the successful performance of the sanitary sewers and also the overlying roadway pavement after construction. Installation of the sewers will require the placement and compaction of a significant volume of granular backfill. The placement of large volumes of fill can lead to excessive settlement during and after construction if not properly placed and compacted.