Willow_Ave_Geotechnical_Report.pdf

Report of Geotechnical Engineering Exploration

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Seminole County, Florida GEC Project No. 4518G

April 14, 2020 Revised June 30, 2020

Metric Engineering 615 Crescent Executive Court, Suite 524 Lake Mary, FL 32746

Attention: Mr. Brian Fuller, P.E.

Subject: Report of Geotechnical Engineering Exploration

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Willow Avenue – Alhambra Avenue Seminole County, Florida GEC Project No. 4518G

Dear Mr. Fuller:

Geotechnical and Environmental Consultants, Inc. (GEC) has completed our geotechnical engineering exploration for the North of Lake Harriet Drainage Improvements project and prepared this report in accordance with our Proposal No. 10009G dated November 12, 2019. The purpose of this study was to develop recommendations to guide site preparation and design of drainage improvements and pavements.

This report describes our methodology, documents our field and laboratory test results and presents our recommendations regarding the geotechnical engineering aspects of the project.

GEC appreciates the opportunity to be of service to you on this project. If you have any questions concerning the contents of this report, or if we may be of further assistance, please contact us.

Sincerely, GEOTECHNICAL AND ENVIRONMENTAL CONSULTANTS, INC.

Certificate of Authorization No. 00005882

Ryan J. Petersen, E.I. Daniel C. Stanfill Engineer Intern Senior Geotechnical Engineer Florida License No. 42763

This Report has been digitally signed and sealed by Daniel C. Stanfill on the date adjacent to the seal. Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

GEC Project No. 4518G ii Report of Geotechnical Engineering Exploration North of Lake Harriet Drainage Improvements

TABLE OF CONTENTS

1.0 SITE LOCATION AND DESCRIPTION

2.0 PROJECT DESCRIPTION

3.0 NRCS SOIL SURVEY

4.0 POTENTIOMETRIC MAP DATA

5.0 SUBSURFACE EXPLORATION

6.0 LABORATORY TESTING

7.0 SUBSURFACE CONDITIONS

7.1 Subsurface Profile

7.2 Groundwater Levels

7.3 Pavement Cores

8.0 DESIGN RECOMMENDATIONS

8.1 Box Culvert Foundation Design

8.2 Foundation Settlement

8.3 Wall/Lateral Earth Pressure Design Parameters

8.4 Uplift Resistance for Submerged Structures

8.5 Pavement Design

8.6 Pavement Base Clearance

9.0 CONSTRUCTION RECOMMENDATIONS

9.1 General Site Preparation

9.2 Unsuitable Soil Excavation

9.3 Construction Materials Quality Control Testing

10.0 REPORT USE AND LIMITATIONS

FIGURES

Figure 1: USGS Quadrangle and NRCS Soil Survey Maps Figure 2: Boring and Pavement Core Location Plan with Muck Probe Results Figures 3 to 5: Soil Boring Results

GEC Project No. 4518G iii Report of Geotechnical Engineering Exploration

TABLES

Table 1: Summary of Proposed Concrete Box Culverts Table 2: NRCS Soil Classifications Table 3: Site Exploration Summary Table 4: Summary of Laboratory Testing Program Tables 5A to 5D: General Subsurface Profile Based on SPT Borings Table 6: Groundwater Levels in Building and Pavement Borings Table 7: Pavement Core results Table 8: Recommended Soil Parameters for Box Culvert Design Table 9: Box Culvert Settlement Table 10: Recommended Pavement Designs Table 11: Corrosion Series Test Results

APPENDIX

A. Central Florida Geology B. Exploration Method Descriptions

B.1 SPT Borings B.2 Manual Auger Borings B.3 Groundwater Measurement B.4 Manual Muck Probes B.5 Corrosion/Redox Sampling B.6 Pavement Cores

C. Laboratory Test Results C.1 Corrosion Series Test Results

D. Design Calculations D.1 Bearing Capacity

E. Construction Recommendations E.1 Groundwater and Surface Water Control E.2 General Site Preparation E.3 Fill Selection, Placement and Compaction E.4 Foundation Subgrade Preparation E.5 Pavement Subgrade Preparation E.6 Excavation Safety E.7 Reclaimed Concrete Aggregate Base Material

GEC Project No. 4518G 1 Report of Geotechnical Engineering Evaluation

1.0 SITE LOCATION AND DESCRIPTION

The project site is located in the residential area found to the north of Lake Harriet in Altamonte Springs, Florida as shown on Figure 1. More specifically the project includes 3 existing culvert sites.

The first site is an approximately 70-foot culvert crossing located on West Lake Brantley Drive approximately 315 feet south of Virginia Drive. The second is an approximately 220-foot culvert along Virginia Drive on the south side of the road that begins approximately 840 feet east of West Lake Brantley Road. The third culvert site includes an approximately 2,300 foot length of culvert that includes crossings at Willow Avenue, Alhambra Avenue and Alder Avenue. This section also includes the culverts that connect between these crossings. The general vicinity of the site is characterized as single family residential.

The approximate site vicinity is shown on an excerpt of the United States Geological Survey (USGS) Forrest City, Florida Quadrangle map on Figure 1 in the Appendix. Based on a review of the USGS Quadrangle map, the ground surface elevation across the site ranges from approximately +50 to +60 feet NGVD.

2.0 PROJECT DESCRIPTION

We understand that project plans include replacing approximately 2,600 feet of total culvert at the three areas with culverts at this project site. We understand that the proposed culverts will be 4 feet tall by 7 feet wide with 10 to 12 inch thick concrete and approximately 2 feet of cover. Table 1 below shows the culvert dimensions. The approximate culvert locations are shown on Figure 2.

We understand the project plans also include restoring the roadway facilities once the culverts are installed.

Table 1: Summary of Proposed Concrete Box Culverts

Box Culvert Location Dimensions

(ft x ft) Length

(ft)

West Lake Brantley Road 4x7 67

Virginia Drive 4x7 221

Willow Avenue to Alder Avenue 4x7 691

If any of the above project information is incorrect, please notify us so that we can evaluate whether the changes in design affect our recommendations.

GEC Project No. 4518G 2 Report of Geotechnical Engineering Evaluation

3.0 NRCS SOIL SURVEY

The Natural Resources Conservation Service (NRCS) Soil Survey of Seminole County, Florida was reviewed for near-surface soil and groundwater information. The NRCS Soil Survey map is shown on Figure 1. The soils near the project site are summarized in Table 2.

Table 2: Summary of NRCS Soil Survey Soil Units

Soil Unit No. Soil Name

Depth (inches) Soil Description

Unified Classification

Symbol

Depth to Seasonal High Groundwater

(feet) Hydrologic

Group

Seffner fine sand, 0 to 2 percent slopes

0 – 18 Fine sand SM, SP-SM

1.5 – 3.5 A/D

18 – 80 Fine sand SP-SM, SC-SM

Urban land, 0 to 2 percent slopes

Urban Land refers to areas where most of the ground surface is covered by asphalt, concrete, buildings and other impervious surfaces that modify surface/subsurface drainage and obscure or alter the soils so that their identification is not possible. The depth to seasonal high groundwater level for this soil unit is typically dependent upon the functioning of existing drainage systems.

Information contained in the NRCS Soil Survey is very general and may be outdated. Therefore, it may not be reflective of actual soil and groundwater conditions, particularly if recent development in the site vicinity has modified soil conditions or surface/subsurface drainage. The information obtained from recent soil borings provides a better characterization of actual site conditions.

4.0 POTENTIOMETRIC MAP DATA

Artesian groundwater conditions can be predicted based on comparison of the Floridan aquifer potentiometric surface and ground surface elevations. The Florida Geological Survey map entitled The Upper Floridan Aquifer Potentiometric Surface Contours, September, 2016 (the most recent map available) indicates the potentiometric surface of the Floridan aquifer at the site is approximately +40 feet NGVD. Since the existing ground surface at the site is approximately +50 to +60 feet NGVD, artesian flow conditions are not anticipated. Additionally, artesian conditions were not encountered in our soil borings. However, our drilling operations required the use of high density drilling mud which could potentially obscure the effect of artesian conditions during drilling. A brief summary of the Central Florida Geology is presented in Appendix A.

GEC Project No. 4518G 3 Report of Geotechnical Engineering Evaluation

5.0 SUBSURFACE EXPLORATION

In addition to consulting published sources, GEC conducted an exploration of the project site to evaluate subsurface conditions. Our field exploration is summarized in Table 3. Please refer to Appendix B for a description of the field exploration methods used for this investigation.

Table 3: Site Exploration Summary

Project Element 1Exploration Method Quantity

Test ID No.

Depth Explored

(feet) Figure

No.

Culverts SPT Borings 12 B-1 to B-12 30 to 50 3 to 5

Muck Probes 36 --- --- 2A to 2C

Pavement HA Borings 8 AB-1 to AB-8 5 3 to 5

Pavement Cores 8 PC-1 to PC-8 --- 2A to 2C

1. SPT = Standard Penetration Test; HA = Hand Auger

The locations of the field activities listed in Table 2 are shown on the site plan in Figure 2. These locations were not surveyed; they were estimated by taping distances from existing features. The approximate method used to locate them is sufficient to meet the intent of our study. However, if greater accuracy is desired a licensed Professional Land Surveyor should survey the locations.

6.0 LABORATORY TESTING

Selected soil samples retrieved from the borings were tested in accordance with Florida Standard Testing Methods (FM) and American Standard Testing Methods (ASTM). Our laboratory testing program is summarized on the following table:

Table 4: Summary of Laboratory Testing Program

Test Test No.

Grain Size Analysis AASHTO T88

Atterberg Limits AASHTO - T89/90 Organic Content FM 1 - T267

Natural Moisture Content AASHTO - T265 Corrosion Series (pH, sulfates, chlorides, and resistivity) FM 5-550/551/552/553

The results of our general laboratory tests (i.e.; grain size, Atterberg limits, organic content and natural moisture content) are shown adjacent to the soil profiles on the Soil Boring Result sheets (Figures 3 to 5). Please refer to Appendix C for the corrosion series test results.

GEC Project No. 4518G 4 Report of Geotechnical Engineering Evaluation

7.0 SUBSURFACE CONDITIONS

GEC’s field exploration was conducted from January 15 to 17, 2020. The soil and groundwater conditions encountered are summarized in this section. Please refer to Figures 3 through 5 for a detailed description of the subsurface profile at each boring location shown on Figure 2. The results of selected laboratory tests are shown adjacent to the subsurface profiles at the depth the samples were obtained.

7.1 Subsurface Profile

Tables 5A through 5D summarize the subsurface conditions encountered in the SPT borings:

Table 5A: General Subsurface Profile – SPT Borings Along West Lake Brantley Road and Virginia Drive (B-1 to B-4)

Layer Depth (feet) Soil Description

SPT

Resistance

(blows/foot)

0 to 30 Loose to medium dense fine sand with silt (SP-SM), and silty fine sand (SM) with occasional some limerock, shell, phosphate, clay and trace organics

6 to 25 (HA to 6ft)

The following exceptions were encountered:

• Boring B-3 encountered a dense blow count at a depth of 20 feet.

• Boring B-4 encountered a stiff sandy lean clay from approximately 23.5 to 30 feet.

Table 5B: General Subsurface Profile – SPT Borings

Along Willow Avenue, Alhambra Avenue and Alder Avenue (B-5, B-6, B-9, B-12)

(feet) Soil Description

SPT

Resistance

(blows/foot)

0 to 14 Loose to medium dense fine sand with silt (SP-SM), and silty fine sand (SM)

5 to 23

14 to 20 Loose to medium dense clayey fine sand (SC) to soft sandy lean clay (CL)

4 to 16

20 to 30 Loose to medium dense fine sand with silt (SP-SM), and silty fine sand (SM)

4 to 18

GEC Project No. 4518G 5 Report of Geotechnical Engineering Evaluation

• Boring B-9 encountered a very loose blow count at a depth of 25 feet.

Table 5C: General Subsurface Profile – SPT Borings Along Willow Avenue, Alhambra Avenue and Alder Avenue (B-7, B-8, B-10)

(feet) Soil Description

SPT

Resistance

(blows/foot)

0 to 17 Loose to medium dense fine sand with silt (SP-SM), and silty fine sand (SM)

4 to 21

17 to 27 Very loose to loose fine sand with silt (SP-SM), and silty fine sand (SM) with occasional trace phosphate

2 to 4

27 to 30 Loose to medium dense fine sand with silt (SP-SM), and silty fine sand (SM) with trace phosphate

6 to 21

Table 5D: General Subsurface Profile – SPT Boring at Alder Avenue (B-11)

(feet) Soil Description

SPT

Resistance

(blows/foot) 0 to 13 Loose to medium dense fine sand with silt (SP-SM) 6 to 16

13 to 22 Dense to very dense fine sand with silt (SP-SM) 38 to 56 22 to 27 Medium dense fine sand with silt (SP-SM) 11 27 to 42 Very loose to loose mucky fine sand (PT) 2 to 6 42 to 47 Loose fine sand with silt (SP-SM) 4 47 to 50 Loose mucky fine sand (PT) 4

• Boring B-11 encountered a weight-of-hammer (W/H) blow count at a depth of 8 feet.

In general the auger borings (AB-1 to AB-8) encountered fine sand (SP) to fine sand with silt (SP- SM) to silty fine sand (SM) within the maximum depth explored of 5 feet. Boring AB-5 encountered a clayey fine sand layer at a depth of 1.5 to 5 feet.

The manual muck probes performed in the open channels at the intakes and outfalls of the existing culverts encountered surficial muck thickness ranging from 0 to 0.2 feet and water depths ranging from 0 to 2.0 feet. For specific surficial muck thickness and water depths, see Figures 2A to 2C.

GEC Project No. 4518G 6 Report of Geotechnical Engineering Evaluation

7.2 Groundwater Levels

Table 6 summarizes the measured and estimated seasonal high groundwater levels in culvert and pavement locations.

Table 6: Groundwater Levels in Building and Pavement Borings

Location Boring ID Nos.

Measured Depths (ft)

(1/15 to 1/17)

Estimated Seasonal High

Depths (ft)

Estimated Average

Seasonal High Depths (ft)

Culvert B-1 to B-12 2.0 – 5.0 0.5 – 3.0 1.6 Pavement AB-1 to AB-8 2.5 – 4.8 1.3 – 2.5 1.9

Please refer to Figures 3 through 5 for measured and estimated seasonal high groundwater levels at each boring location shown on Figure 2.

7.3 Pavement Cores

In addition to the field exploration activities described above GEC also conducted 8 pavement cores (PC-1 to PC-8). The table below documents the pavement and base thicknesses encountered at each core location shown on Figure 2.

Table 7: Pavement Core Results Core No.

Core Length

(in) 1Base Type

Base Thickness (in)

Subgrade Type

PC-1 2.25 LR 10.5 SM

PC-2 2.25 LR 14 SM

PC-3 1.25 Stabilized Subgrade 12 SP-SM PC-4 1.25 Stabilized Subgrade 12 SP

PC-5 1.25 LR 10.25 SP

PC-6 3.0 LR 7.75 SP

PC-7 3.25 Stabilized Subgrade 9.75 SP-SM

PC-8 2.5 LR 9.5 SM

1.LR= Limerock

8.0 DESIGN RECOMMENDATIONS

GEC developed the following recommendations based on the results of our field and laboratory testing program. These recommendations are only applicable if the site is prepared in accordance with the construction requirements provided in Section 9.0 of this report and Appendix E.

GEC Project No. 4518G 7 Report of Geotechnical Engineering Evaluation

8.1 Box Culvert Foundation Design

The site is suitable for support of the proposed box culverts. Design soil parameters for the box culvert are presented on Table 8 below. The soil parameters provided below were developed based on the general subsurface profiles encountered throughout the project site.

Table 8: Recommended Soil Parameters for Box Culvert Design

It is noted that the foundation elements of the existing residences must be adequately supported during excavation and placement of the proposed culverts. Methods of supporting the existing foundations should be determined by the contractor or his engineer, but may include bracing, underpinning and/or other appropriate methods.

8.2 Foundation Settlement

Our analysis indicates that the box culverts designed in accordance with the above recommendations, assuming supporting loads no larger than those previously described, will experience settlements found in the table below. The majority of this settlement is anticipated to occur during construction.

Table 9: Box Culvert Settlement

Box Culvert Location Effective Length

(ft)

Differential Settlement

(in)

Total Settlement

(in) West Lake Brantley Road 67 0.5 1.0

Virginia Drive 221 0.5 1.0 Willow Avenue to Alder Avenue 691 0.5 1.0

Project Element Soil Soil Type

2.Nominal Bearing

Resistance

(NBR)

(psf)

Saturated Unit

Weight (pcf)

Effective (Buoyant)

Unit Weight

(pcf)

Angle of Internal

Friction, φ (degrees)

Modulus of Subgrade Reaction

(pci) --- Backfill (sands) SP, SP-SM N/A 110 50 30 N/A

Culvert Foundations from W. Lake Brantley Rd. to 150 feet west of

Alder Ave Foundation

1.SP to SP- SM to SM

3000 110 50 30 100

Culvert Foundations from 150 feet west of Alder Ave. to east of Alder

Ave.

Foundation 1.SP-SM 2000 100 40 28 100

Notes:

1. Any surficial (PT) material should be removed and replaced with Select (S) material.

2. NBR calculated using a Phi Factor of 0.45 per AASHTO LRFD guidelines. Endwall/wingwall footings should be designed with a Nominal Bearing Resistance of 3,000 psf and should be designed by the structural engineer to resist the anticipated loading.

GEC Project No. 4518G 8 Report of Geotechnical Engineering Evaluation

Settlement of the adjacent residences may occur during construction if the existing residence foundations are not property protected. Any additional settlement may result in minor cracks in the existing residences. The construction budget for this project should allow for cosmetic repairs to the existing residences, if cracking occurs.

8.3 Wall/Lateral Earth Pressure Design Parameters

Lateral earth pressure for design of walls and other below-grade structures should be calculated using the following soil parameters:

• Friction Angle (degrees) = 30

• Moist Unit Weight (pcf) = 110

• Saturated Unit Weight (pcf) = 115

• Buoyant Unit Weight (pcf) = 55

• Angle of Wall Friction (degrees) = 15

• Base Friction Coefficient = 0.50

The active, passive and at-rest earth pressures can be calculated using these parameters. The earth pressure condition will be dependent on wall design. Frictional resistance at the foundation base can be calculated by multiplying the base contact pressure by the friction coefficient. The above soil parameters do not include a factor of safety; appropriate safety factors should be applied in the wall design calculations.

The estimated seasonal high groundwater levels included in this report can be used for guidance when determining the design high water level for structure design. If drainage through the wall cannot be assured, we recommend using the ground surface elevation at the top of the structure for the design high water level.

GEC should review the final wall analysis and plans to verify that our recommendations have been correctly applied in the wall design.

8.4 Uplift Resistance for Submerged Structures

Structures below the water table will be subjected to uplift (buoyant) forces. The components resisting buoyancy include the following:

• Weight of the structure

• Weight of the soil above the structure

• Shear forces on planes that radiate vertically from the perimeter of the structure to the ground surface

GEC Project No. 4518G 9 Report of Geotechnical Engineering Evaluation

The allowable unit shearing resistance (Fa) in psf may be determined by the following formula:

• Fa = Ko γm h (⅔ tan Φ) /S.F. (above water table)

• Fa = Ko (γs - γW) h (⅔ tan Φ) /S.F. (below water table)

Where, Ko = coefficient of earth pressure at rest = 0.5 γm = unit weight of moist soil = 110 pcf γs = saturated unit weight of soil = 115 pcf γW = unit weight of water = 62.4 pcf h = vertical depth below grade at which shearing resistance is calculated Φ = soil internal friction angle = 30 degrees S.F. = safety factor = 2

These design parameters are based on the assumption that fill above and/or surrounding the structure will achieve the construction requirements provided in Appendix E.

8.5 Pavement Design

Our investigation indicates that the site can be made suitable for support of conventional flexible (asphalt) or rigid (concrete) pavement sections. Table 10 presents our recommended pavement sections. These pavement sections are typical of similar projects in Central Florida and are not based on traffic loading information, which was not available when this report was prepared.

Table 10: Recommended Pavement Designs

Traffic Type Surface Course Base Course Stabilized Subgrade

Light Duty – parking stalls

1.5 inches Asphalt Surface Course

6 inches limerock (LBR 100 min)

12 inches (LBR=40)

7 inches reclaimed concrete aggregate (LBR 150 min)

12 inches (LBR=40)

8 inches soil-cement (300 psi min)

Stabilization not required*

Medium Duty – parking lot drive lanes and perimeter roads

2.0 inches Asphalt Surface Course

8 inches limerock (LBR 100 min)

12 inches (LBR=40)

7 inches reclaimed concrete aggregate (LBR 150 min)

12 inches (LBR=40)

10 inches soil-cement (300 psi min)

Stabilization not required*

GEC Project No. 4518G 10 Report of Geotechnical Engineering Evaluation

Traffic Type Surface Course Base Course Stabilized Subgrade

Heavy Duty – truck turning movements, loading areas

6.0 inches concrete (4,000 psi 28-day min)

Base course not required

12 inches (95% Modified Proctor Compaction only) Stabilization not required*

‘*’ Free draining subgrade soils (e.g. sands with <12% fines) are recommended to promote drainage of infiltrating water.

If traffic loading information becomes available, we should review it to confirm the suitability of these typical pavement sections.

Additional recommendations for using reclaimed concrete aggregate (RCA) are provided in Appendix E.

8.6 Pavement Base Clearance

Vertical separation of the base from the water table is required to prevent pavement damage created by inundation of the base course during periods of heavy rainfall. We recommend a minimum of 24 inches of separation between the bottom of the pavement base and the estimated seasonal high groundwater level. If this vertical clearance cannot be provided, limerock should not be used for the base material. A soil-cement base course or asphalt base course (black base) can be constructed with a minimum vertical base clearance of 12 inches. Underdrains will be required to artificially lower the water table where the seasonal high groundwater level is within 12 inches of the bottom of the base.

These conclusions are contingent upon preparation of proposed pavement areas in accordance with the requirements of Appendix E.

9.0 CONSTRUCTION RECOMMENDATIONS

9.1 General Site Preparation

Our recommendations for general construction activities are presented in Appendix E, which addresses the following requirements:

• Groundwater and Surface Water Control

• General Site Preparation

• Fill Selection, Placement and Compaction

• Foundation Subgrade Preparation

• Pavement Subgrade Preparation

GEC Project No. 4518G 11 Report of Geotechnical Engineering Evaluation

• Excavation Safety

• Reclaimed Concrete Aggregate Base Material

9.2 Unsuitable Soil Excavation

The muck in soil boring B-11 encountered at a depth of 27 feet shall remain. If any other organic soils are encountered within the culvert excavations it should be removed within 5 feet of the culvert foundation. Muck excavation should be performed “in the dry” so that removal can be verified and to facilitate excavation backfill compaction. It will be critical to adhere to the site dewatering, site preparation and fill selection, placement and compaction requirements in Appendix E to ensure adequate muck removal. If any organic material is encountered that was not encountered in this exploration, please notify us so that we can evaluate whether the changes in site conditions affect our recommendations

In addition, full-time inspection of demucking operations by an engineering technician working under the supervision of a Florida-licensed geotechnical engineer is strongly recommended. Full-time inspection is needed to verify complete removal, and to prevent the removal of suitable soil that would unnecessarily increase construction costs. Allowing construction equipment operators to determine muck removal limits commonly results in cost overruns that could be avoided if a trained inspector is on-site to properly classify excavated soils.

9.3 Construction Materials Quality Control Testing

A comprehensive quality control program is required to verify that site preparation and foundation, pavement and pond construction is conducted in accordance with the recommendations in this report including Appendix E. Materials testing and inspection services should be provided by Geotechnical and Environmental Consultants, Inc. due to our knowledge of the site conditions and understanding of the intent of our recommendations.

10.0 REPORT USE AND LIMITATIONS

This section of the report presents important information regarding the proper use of this report, our investigative methods and the limitations of this study. The test data, conclusions and recommendations presented in this report should be reviewed and applied with these limitations in mind.

Subsurface Variability. The analyses and recommendations contained in this report are based in part on the data obtained from a limited number of soil samples and groundwater measurements obtained from widely-spaced borings/piezometers. The sampling methods used indicate subsurface conditions only at the specific boring locations where samples were obtained, only at

GEC Project No. 4518G 12 Report of Geotechnical Engineering Evaluation the time they were obtained, and only to the depths penetrated. Borings cannot be relied upon to accurately reflect the variations that usually exist between boring locations and these variations may not become evident until construction. Conditions at the boring locations can change over time. Groundwater levels fluctuate seasonally, and soil conditions can be altered by earthmoving operations.

Manual Probes. Manual muck probes were performed by pushing a slender metal rod into the surficial soil and evaluating the relative resistance of the soil to manual penetration. Highly organic soils, such as muck and/or peat, are characteristically very soft and will easily yield to the manual probe. Manual probes, however, cannot detect peat or muck layers which are present beneath layers of sand or dense soils which cannot be penetrated by the probe. The probes can also penetrate to some extent in very loose sands which may be present beneath peat or muck layers.

No soil samples are obtained for visual examination or laboratory testing when using this exploratory technique. The soil type being penetrated is inferred solely by evaluating the relative resistance of the soil to penetration. These limitations can lead to some under-estimation or over-estimation of peat or muck layer thicknesses. The probe data presented in this report should be evaluated with these limitations in mind.

Soil Stratification. The depths and thicknesses of the subsurface strata indicated on the boring logs were interpolated between samples obtained at different depths in the borings. The actual transition between soil layers may be different than indicated. These stratification lines were used for our analytical purposes. Earthwork quantity estimates based on the results of the borings will vary from the actual quantities measured during construction.

Groundwater Measurements. Groundwater levels can vary seasonally and with changes in subsurface conditions between boring and/or piezometer locations. Alterations in surface and/or subsurface drainage brought about by site development can also affect groundwater levels.

Therefore, groundwater depths measured at different times or at different locations on the site can be expected to vary from those measured by GEC during this investigation.

Groundwater Predictions. For purposes of this report, estimated seasonal high groundwater levels are defined as groundwater levels that are anticipated at the end of the wet season during a “normal rainfall” year under pre-development site conditions. We define a “normal rainfall” year as a year in which rainfall quantity and distribution were at or near historical averages.

Construction Variations. If variations from the subsurface conditions described in this report do become evident during construction, GEC should be retained to reevaluate this report's conclusions and recommendations, and modify the recommendations included in this report, if needed, in light of such changes.

GEC Project No. 4518G 13 Report of Geotechnical Engineering Evaluation

Plans/Specifications Review. GEC should be provided with the construction plans and specifications prior to bidding so that we can verify that the recommendations presented in this report were correctly interpreted and incorporated into the plans and specifications. The recommendations in this report were not written in specification language and are not intended to be used verbatim as a part of the plans and specifications. This report should not be wholly incorporated into the project contract documents.

Design Changes. The conclusions or recommendations of this report should be disregarded if the nature, design, or location of the facilities is changed. If such changes are contemplated, GEC should be retained to review the new plans to assess the applicability of this report in light of the proposed changes.

Contamination Exclusion. The sole purpose of the borings performed by GEC at this site was to obtain indications of subsurface conditions as part of a geotechnical exploration program. GEC has not evaluated the site for the potential presence of contaminated soil or groundwater, nor have we subjected any soil samples to analysis for contaminants.

Report Reliance. GEC has prepared this report for the exclusive use of our client, Metric, and for specific application to this project. GEC is not responsible for any third party’s interpretation or use of this report’s subsurface data, engineering analysis or recommendations without our written authorization.

Standard of Care. GEC has performed the services described in this report in a manner consistent with that level of care and skill ordinarily exercised by members of our profession currently practicing in Central Florida. No other representation is made or implied in this document.

FIGURES

993110

W:\Projects\J4518G North of Lake Harriet Drainage Imp\Geotechnical\7 CADD Files\4518Gquadrangle.mxd 4/14/2020

Geotechnical and Environmental 919 Lake Baldwin Lane Orlando, FL 32814

PH (407) 898-1818 FAX (407) 898-1837

Certificate of Authorization No. 00005882

PROJECT NO.

4518G USGS QUADRANGLE AND NRCS SOIL SURVEY MAPS

NORTH OF LAKE HARRIET

DRAINAGE IMPROVEMENTS

Consultants, Inc.

FIGURE

NO.

4/14/2020DATE

SKR

DRAWN BY

RJP

CHECKED BY

DCSCHECKED BY

:APPROXIMATE BOX CULVERT LOCATION

DANIEL C. STANFILL P.E. 42763

NRCS Soil Survey of Seminole County, FL Seminole County Map Unit Legend 30 - Seffner fine sand, 0 to 2 percent slopes 34 - Urban land, 0 to 2 percent slopes

0 1,000500

Feet

USGS Forest City, FL Quadrangle Map Dated: 1959

0 2,0001,000

Feet

GEC

&<B-2

B-1

AB-2

PC-2

PC-1AB-1

W:\Projects\J4518G North of Lake Harriet Drainage Imp\Geotechnical\7 CADD Files\4518G2A.mxd 4/14/2020

Geotechnical and Environmental

: 919 Lake Baldwin Lane Orlando, FL 32814

PH (407) 898-1818 FAX (407) 898-1837

Certificate of Authorization No. 00005882 GEC PROJECT NO.

4518G BORING AND PAVEMENT CORE LOCATION PLAN

WITH MUCK PROBE RESULTS

NORTH OF LAKE HARRIET

DRAINAGE IMPROVEMENTS

Consultants, Inc.

FIGURE

NO.

2A 4/14/2020

DATE

SKR

DRAWN BY

RJP

CHECKED BY

DCSCHECKED BY

0 6030

Feet

APPROXIMATE MUCK PROBE LOCATION!(

DANIEL C. STANFILL P.E. 42763

0.3 | 0.0

0.0 | 0.0

0.5 | 0.1

1.0 | 0.0

0.0 | 0.0

1.5 | 0.0

0.5 | 0.0

0.5 | 0.0

1.5 | 0.0

0.5 | 0.0

1.0 | 0.0

1.5 | 0.0

B-2

B-1

AB-2

PC-2

PC-1AB-1

Scale: 1"-20'

MUCK PROBE AREAS A & B

APPROXIMATE SPT BORING LOCATION

APPROXIMATE AUGER BORING LOCATION

APPROXIMATE PAVEMENT CORE LOCATION

0.3 | 0.1

STANDING WATER DEPTH (FT.)

SURFICIAL MUCK THICKNESS (FT.)

MUCK PROBE AREA A

MUCK PROBE AREA B

B-4

B-3

W:\Projects\J4518G North of Lake Harriet Drainage Imp\Geotechnical\7 CADD Files\4518G2B.mxd 4/14/2020

Geotechnical and Environmental

: 919 Lake Baldwin Lane Orlando, FL 32814

PH (407) 898-1818 FAX (407) 898-1837

Certificate of Authorization No. 00005882 GEC PROJECT NO.

4518G BORING LOCATION PLAN WITH MUCK PROBE RESULTS

NORTH OF LAKE HARRIET

DRAINAGE IMPROVEMENTS

Consultants, Inc.

FIGURE

NO.

2B 4/14/2020

DATE

SKR

DRAWN BY

RJP

CHECKED BY

DCSCHECKED BY

0 6030

Feet

APPROXIMATE MUCK PROBE LOCATION!(

DANIEL C. STANFILL P.E. 42763

!(0.0 | 0.1

1.5 | 0.0

0.2 | 0.0 0.0 | 0.2

0.0 | 0.0

1.5 | 0.0

Scale: 1"-20'

MUCK PROBE AREA C

APPROXIMATE SPT BORING LOCATION

APPROXIMATE AUGER BORING LOCATION

APPROXIMATE PAVEMENT CORE LOCATION

0.3 | 0.1

STANDING WATER DEPTH (FT.)

SURFICIAL MUCK THICKNESS (FT.)

MUCK PROBE AREA C

MUCK PROBE AREA D

B-4

0.2 | 0.0

2.0 | 0.0

0.3 | 0.1 0.3 | 0.0

0.2 | 0.0

2.0 | 0.0

Scale: 1"-20'

MUCK PROBE AREA D

B-9

B-8

B-7B-6

B-5

PC-5

AB-6

AB-4

PC-6

AB-3

PC-8

PC-7

AB-8

AB-7 B-12

B-11

B-10AB-5

PC-4

PC-3

W:\Projects\J4518G North of Lake Harriet Drainage Imp\Geotechnical\7 CADD Files\4518G2C.mxd 4/14/2020

Geotechnical and Environmental

: 919 Lake Baldwin Lane Orlando, FL 32814

PH (407) 898-1818 FAX (407) 898-1837

Certificate of Authorization No. 00005882 GEC PROJECT NO.

4518G BORING LOCATION PLAN WITH MUCK PROBE RESULTS

NORTH OF LAKE HARRIET

DRAINAGE IMPROVEMENTS

Consultants, Inc.

FIGURE

NO.

2C 4/14/2020

DATE

SKR

DRAWN BY

RJP

CHECKED BY

DCSCHECKED BY

0 6030

Feet

APPROXIMATE MUCK PROBE LOCATION!(

DANIEL C. STANFILL P.E. 42763

AB-4PC-4

0.1 | 0.1

0.1 | 0.0

0.4 | 0.0

0.2 | 0.0

0.1 | 0.0

0.4 | 0.0

Scale: 1"-20'

MUCK PROBE AREA E

APPROXIMATE SPT BORING LOCATION

APPROXIMATE AUGER BORING LOCATION

APPROXIMATE PAVEMENT CORE LOCATION

0.3 | 0.1

STANDING WATER DEPTH (FT.)

SURFICIAL MUCK THICKNESS (FT.)

MUCK PROBE AREA E MUCK PROBE AREA F

PC-8

PC-7

AB-8

AB-7

B-12

B-11

1.0 | 0.0

0.0 | 0.2

0.2 | 0.0

0.1 | 0.0

0.1 | 0.0

0.0 | 0.0

Scale: 1"-20'

MUCK PROBE AREA F

WILLOW AVENUE

ALDER AVENUE

APPENDIX A

CENTRAL FLORIDA GEOLOGY

A. CENTRAL FLORIDA GEOLOGY

Central Florida geology is defined by the nature and relationship of three sedimentary layers. The deepest layer is cavernous limestone known as the Floridan aquifer (Floridan).

The Floridan is overlain by the clayey sand to sandy clay of the Hawthorn Group (Hawthorn). The Hawthorn is in turn overlain by a surface layer of sand, which comprises the water table aquifer.

Central Florida geology is classified as “karst” or sinkhole-prone. Where the Hawthorn is absent, water and sand can flow downward to cavities within Floridan aquifer, like sand through an hourglass, recharging the Floridan aquifer, and sometimes causing the formation of surface depressions, or sinkholes. This process of subsurface erosion caused by recharge is known as raveling. Thus, areas of groundwater recharge to the Floridan aquifer are more likely to experience sinkhole activity.

No field exploration method can accurately predict the occurrence of sinkholes. It is common geotechnical practice in Central Florida to assess sinkhole risk at a site based on published geology and recent sinkhole history. Further evaluation can be made by performing deep soil borings. The purpose of the borings is to explore the Hawthorn and overlying sands for indicators of sinkhole activity, including extensive zones of loose, raveled soil and losses of drilling fluid circulation. Evaluation of sinkhole risk by deep borings is typically performed for significant structures, but is not usually performed for horizontal facilities such as highways. It is generally considered that the cost of performing such an evaluation for that type of facility would not be cost-effective when compared to the benefit derived.

In some instances, sinkholes formed in wetlands, or by their formation the sinkholes created wetlands. These sinkholes often filled with highly compressible organic soil (peat and/or muck), sometimes to depths greater than 100 feet. Although these relic sinkholes do not typically reactivate, the highly compressible nature of the organic soil can cause excessive settlement of roadways, structures or other facilities that may be constructed over them.

APPENDIX B

FIELD EXPLORATION METHODS

B. FIELD EXPLORATION METHODS

B.1 SPT Borings

Standard Penetration Test (SPT) borings were drilled in general accordance with ASTM Procedure D-1586. The boreholes were advanced by the rotary wash method with bentonite-based mud used as the circulating fluid to help remove cuttings and to help stabilize the borehole. Casing was used as necessary to further stabilize the borehole and prevent loose surficial sands from raveling into the lower more stable portions of the borehole. GEC’s field crew obtained SPT samples continuously in the borings to a depth of 10 feet and at 5-foot depth intervals thereafter. When necessary, a hand auger boring was performed to a depth of 6 feet to clear for subsurface utilities and then SPT samples were continuously in the borings to a depth of 10 feet and at 5-foot depth intervals thereafter. A GEC engineering technician supervised the drilling operation, and collected, examined and visually classified each sample. Representative samples were collected for further visual examination and classification in the GEC laboratory. SPT borings that penetrate the Hawthorn Group are grout-sealed upon completion.

B.2 Manual Auger Borings

A GEC engineering technician performed standard barrel manual auger borings in general accordance with ASTM D-1452, by manually turning a 3-inch diameter, 6-inch long sampler into the soil until it was full. He then retrieved the sampler and visually examined and classified the soil. This procedure was repeated until the desired termination depth was achieved.

Representative samples were collected for further visual examination and classification in the GEC laboratory.

B.3 Groundwater Measurement

A GEC engineering technician measured the depth to groundwater in the boreholes at the time of drilling and again after approximately 24 hours. For SPT borings that were grout sealed upon completion, a manual auger boring was performed adjacent to the grouted borehole to record the groundwater depth. Once the 24-hour groundwater measurement was recorded, the boreholes were then backfilled with soil cuttings to prevailing ground surface.

B.4 Manual Muck Probes

Manual muck probes were performed by pushing a slender metal rod into the surficial soil and evaluating the relative resistance of the soil to manual penetration. Highly organic soils, such as muck and/or peat, are characteristically very soft and will easily yield to the manual probe.

Manual probes, however, cannot detect peat or muck layers which are present beneath layers of sand or dense soils which cannot be penetrated by the probe. The probes can also penetrate to some extent in very loose sands which may be present beneath peat or muck layers. No soil samples are obtained for visual examination or laboratory testing when using this exploratory technique. The soil type being penetrated is inferred solely by evaluating the relative resistance of the soil to penetration. These limitations can lead to some under-estimation or over-estimation of peat or muck layer thicknesses. The probe data presented in this report should be evaluated with these limitations in mind.

B.5 Corrosion Sampling

Soil samples were obtained for corrosion testing. The samples were obtained at or near structure boring locations. The samples were immediately placed in glass jars and returned to our laboratory for chemical testing.

B.6 Pavement Cores

Pavement cores were conducted using a 4 or 6-inch diameter core barrel and were cored through the pavement and to the bottom of the base material. A manual auger boring was then performed at the bottom of the cored hole to collect a sample of the subgrade material. After the pavement core was completed, the hole was backfilled with soil cuttings and patched with cold patch asphalt [or high strength quick setting cement] to the pavement surface. A “Pavement Evaluation Coring and Condition” data form (State Form # 675-030-09) was prepared documenting the pavement and base thicknesses, pavement and base types, crack classification, crack depth, cross slope, rut depth and pavement condition classification at each core location.

APPENDIX C

LABORATORY TEST RESULTS

Table 11 Corrosion Series Test Results

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

GEC Project No. 4518G

B-1 SP-SM 6 - 8 7.5 13000 30 < 6 Slightly Aggressive Slightly Aggressive B-3 SP 15 7.2 15000 15 < 6 Slightly Aggressive Slightly Aggressive B-4 SM 6 - 8 5.7 14500 30 39 Moderately Aggressive Extremely Aggressive B-5 SM 4 - 6 6.0 20000 30 < 6 Slightly Aggressive Moderately Aggressive B-7 SP-SM 2 - 4 7.2 12500 30 12 Slightly Aggressive Slightly Aggressive B-8 SP-SM 2 - 4 6.9 28000 15 < 6 Slightly Aggressive Moderately Aggressive B-9 SM 8 - 10 5.2 41000 15 6 Moderately Aggressive Extremely Aggressive

B-10 SP-SM 4 - 6 6.9 21000 30 < 6 Slightly Aggressive Moderately Aggressive B-11 SP-SM 15 7.3 10500 15 < 6 Slightly Aggressive Slightly Aggressive

Boring No.

UNIFIED

Class. Concrete Steel

Substructural Environmental ClassificationSample Depth

(ft) pH

Minimum Resistivity (ohm-cm)

Chlorides (ppm)

Sulfates (ppm)

APPENDIX D

DESIGN CALCULATIONS

Foundation Input Parameters B: 9 ft (width of foundation) L: 70 ft (length of foundation) D: 2 ft (depth of foundation) β: 0 ˚ (inclination of the load)

Soil and Groundwater Input Parameters γ: 105 pcf (unit weight of soil) γsat: 110 pcf (saturated unit weight of soil) c': 0 psf (cohesion) d: 0.5 ft (depth of water table) Ǿ: 30 ˚ (friction angle)

Nq = 18.40 = tan2(45 + Ǿ/2)e π tanǾ, (Reissner, 1924) Nc = 30.14 = (Nq - 1)cotǿ, (Prandtl, 1921) Nγ = 22.40 = 2(Nq + 1)tanǿ, (Caquot and Kerisel, 1953 & Vesic, 1973)

Fcs = 1.08 = 1 + (B/L)(Nq/Nc) Fqs = 1.07 = 1 + (B/L)tanǿ Fγs = 0.95 = 1 - 0.4(B/L)

Fcd = 1.09 = 1 + 0.4(D/B) if D/B ≤ 1 or = 1+ 0.4tan-1(D/B) if D/B > 1

Fqd = 1.06 = 1+2tanǿ(1-sinǿ)2(D/B) if D/B≤1 or =1+2tanǿ(1-sinǿ)2tan-1(D/B) if D/B>1

Fγd = 1

Fci = Fqi = 1.00 = (1 - β˚/90˚)2

Fγi = 1.00 = (1 - β/ǿ)2 q = 123.90 psf Correct for water table if d ≤ D, q = dγ + (D-d)(γsat - γw), else q =γdD γ = 47.60 pcf Correct for water table if d ≤ D, γ = γ' = γsat - γw if (d - D) ≤ B, γ = γ' + (d-D)/B * (γ - γ') qu = 7158 psf (qu = c'NcFcsFcdFci + qNqFqsFqdFqi+½γBNγFγsFγdFγi) qr = 3221 psf (qr = quΦbc)

Φbc = Bearing Capacity Resistance Factor, LRFD Table 10.5.5.2.2-1, = 0.45

BEARING CAPACITY CALCULATIONS

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

West Lake Brantley Road (B-1, B-2) GEC Project No. 4518G

General Bearing Capacity Equation (Meyerhof, 1963) q u = c'N c F cs F cd F ci + qN q F qs F qd F qi +½γBN γ F γs F γd F γi

General Bearing Capacity

Inclination Factors (Hanna and Meyerhof, 1981)

Effective Surcharge & Unit Weight of Soil

Bearing Capacity Factors

Shape Factors (De Beer, 1970)

Depth Factors (Hansen, 1970)

B

D d Water Table β γ; ǿ; c’ γsat; ǿ; c’

L: 220 ft (length of foundation) D: 2 ft (depth of foundation) β: 0 ˚ (inclination of the load)

Soil and Groundwater Input Parameters γ: 105 pcf (unit weight of soil) γsat: 110 pcf (saturated unit weight of soil) c': 0 psf (cohesion) d: 0.5 ft (depth of water table) Ǿ: 30 ˚ (friction angle)

Nq = 18.40 = tan2(45 + Ǿ/2)e π tanǾ, (Reissner, 1924) Nc = 30.14 = (Nq - 1)cotǿ, (Prandtl, 1921) Nγ = 22.40 = 2(Nq + 1)tanǿ, (Caquot and Kerisel, 1953 & Vesic, 1973)

Fcs = 1.02 = 1 + (B/L)(Nq/Nc) Fqs = 1.02 = 1 + (B/L)tanǿ Fγs = 0.98 = 1 - 0.4(B/L)

Fcd = 1.09 = 1 + 0.4(D/B) if D/B ≤ 1 or = 1+ 0.4tan-1(D/B) if D/B > 1

Fqd = 1.06 = 1+2tanǿ(1-sinǿ)2(D/B) if D/B≤1 or =1+2tanǿ(1-sinǿ)2tan-1(D/B) if D/B>1

Fγd = 1

Fci = Fqi = 1.00 = (1 - β˚/90˚)2

Fγi = 1.00 = (1 - β/ǿ)2 q = 123.90 psf Correct for water table if d ≤ D, q = dγ + (D-d)(γsat - γw), else q =γdD γ = 47.60 pcf Correct for water table if d ≤ D, γ = γ' = γsat - γw if (d - D) ≤ B, γ = γ' + (d-D)/B * (γ - γ') qu = 7204 psf (qu = c'NcFcsFcdFci + qNqFqsFqdFqi+½γBNγFγsFγdFγi) qr = 3242 psf (qr = quΦbc)

Φbc = Bearing Capacity Resistance Factor, LRFD Table 10.5.5.2.2-1, = 0.45

Depth Factors (Hansen, 1970)

Inclination Factors (Hanna and Meyerhof, 1981)

Effective Surcharge & Unit Weight of Soil

General Bearing Capacity

BEARING CAPACITY CALCULATIONS

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Virginia Drive (B-3, B-4) GEC Project No. 4518G

General Bearing Capacity Equation (Meyerhof, 1963) q u = c'N c F cs F cd F ci + qN q F qs F qd F qi +½γBN γ F γs F γd F γi

Bearing Capacity Factors

Shape Factors (De Beer, 1970)

B

D d Water Table β

L: 680 ft (length of foundation) D: 2 ft (depth of foundation) β: 0 ˚ (inclination of the load)

Soil and Groundwater Input Parameters γ: 105 pcf (unit weight of soil) γsat: 110 pcf (saturated unit weight of soil) c': 0 psf (cohesion) d: 0.5 ft (depth of water table) Ǿ: 30 ˚ (friction angle)

Nq = 18.40 = tan2(45 + Ǿ/2)e π tanǾ, (Reissner, 1924) Nc = 30.14 = (Nq - 1)cotǿ, (Prandtl, 1921) Nγ = 22.40 = 2(Nq + 1)tanǿ, (Caquot and Kerisel, 1953 & Vesic, 1973)

Fcs = 1.01 = 1 + (B/L)(Nq/Nc) Fqs = 1.01 = 1 + (B/L)tanǿ Fγs = 0.99 = 1 - 0.4(B/L)

Fcd = 1.09 = 1 + 0.4(D/B) if D/B ≤ 1 or = 1+ 0.4tan-1(D/B) if D/B > 1

Fqd = 1.06 = 1+2tanǿ(1-sinǿ)2(D/B) if D/B≤1 or =1+2tanǿ(1-sinǿ)2tan-1(D/B) if D/B>1

Fγd = 1

Fci = Fqi = 1.00 = (1 - β˚/90˚)2

Fγi = 1.00 = (1 - β/ǿ)2 q = 123.90 psf Correct for water table if d ≤ D, q = dγ + (D-d)(γsat - γw), else q =γdD γ = 47.60 pcf Correct for water table if d ≤ D, γ = γ' = γsat - γw if (d - D) ≤ B, γ = γ' + (d-D)/B * (γ - γ') qu = 7218 psf (qu = c'NcFcsFcdFci + qNqFqsFqdFqi+½γBNγFγsFγdFγi) qr = 3248 psf (qr = quΦbc)

Φbc = Bearing Capacity Resistance Factor, LRFD Table 10.5.5.2.2-1, = 0.45

Depth Factors (Hansen, 1970)

Inclination Factors (Hanna and Meyerhof, 1981)

Effective Surcharge & Unit Weight of Soil

General Bearing Capacity

BEARING CAPACITY CALCULATIONS

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Willow Ave, Alhambra Ave, Alder Ave (B-5, B-6, B-9, B-12) GEC Project No. 4518G

General Bearing Capacity Equation (Meyerhof, 1963) q u = c'N c F cs F cd F ci + qN q F qs F qd F qi +½γBN γ F γs F γd F γi

Bearing Capacity Factors

Shape Factors (De Beer, 1970)

B

D d Water Table β

L: 680 ft (length of foundation) D: 2 ft (depth of foundation) β: 0 ˚ (inclination of the load)

Soil and Groundwater Input Parameters γ: 105 pcf (unit weight of soil) γsat: 110 pcf (saturated unit weight of soil) c': 0 psf (cohesion) d: 0.5 ft (depth of water table) Ǿ: 30 ˚ (friction angle)

Nq = 18.40 = tan2(45 + Ǿ/2)e π tanǾ, (Reissner, 1924) Nc = 30.14 = (Nq - 1)cotǿ, (Prandtl, 1921) Nγ = 22.40 = 2(Nq + 1)tanǿ, (Caquot and Kerisel, 1953 & Vesic, 1973)

Fcs = 1.01 = 1 + (B/L)(Nq/Nc) Fqs = 1.01 = 1 + (B/L)tanǿ Fγs = 0.99 = 1 - 0.4(B/L)

Fcd = 1.09 = 1 + 0.4(D/B) if D/B ≤ 1 or = 1+ 0.4tan-1(D/B) if D/B > 1

Fqd = 1.06 = 1+2tanǿ(1-sinǿ)2(D/B) if D/B≤1 or =1+2tanǿ(1-sinǿ)2tan-1(D/B) if D/B>1

Fγd = 1

Fci = Fqi = 1.00 = (1 - β˚/90˚)2

Fγi = 1.00 = (1 - β/ǿ)2 q = 123.90 psf Correct for water table if d ≤ D, q = dγ + (D-d)(γsat - γw), else q =γdD γ = 47.60 pcf Correct for water table if d ≤ D, γ = γ' = γsat - γw if (d - D) ≤ B, γ = γ' + (d-D)/B * (γ - γ') qu = 7218 psf (qu = c'NcFcsFcdFci + qNqFqsFqdFqi+½γBNγFγsFγdFγi) qr = 3248 psf (qr = quΦbc)

Φbc = Bearing Capacity Resistance Factor, LRFD Table 10.5.5.2.2-1, = 0.45

Depth Factors (Hansen, 1970)

Inclination Factors (Hanna and Meyerhof, 1981)

Effective Surcharge & Unit Weight of Soil

General Bearing Capacity

BEARING CAPACITY CALCULATIONS

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Willow Ave, Alhambra Ave, Alder Ave (B-7, B-8, B-10)

GEC Project No. 4518G

General Bearing Capacity Equation (Meyerhof, 1963) q u = c'N c F cs F cd F ci + qN q F qs F qd F qi +½γBN γ F γs F γd F γi

Bearing Capacity Factors

Shape Factors (De Beer, 1970)

B

D d Water Table β

L: 150 ft (length of foundation) D: 2 ft (depth of foundation) β: 0 ˚ (inclination of the load)

Soil and Groundwater Input Parameters γ: 95 pcf (unit weight of soil) γsat: 100 pcf (saturated unit weight of soil) c': 0 psf (cohesion) d: 0.5 ft (depth of water table) Ǿ: 28 ˚ (friction angle)

Nq = 14.72 = tan2(45 + Ǿ/2)e π tanǾ, (Reissner, 1924) Nc = 25.80 = (Nq - 1)cotǿ, (Prandtl, 1921) Nγ = 16.72 = 2(Nq + 1)tanǿ, (Caquot and Kerisel, 1953 & Vesic, 1973)

Fcs = 1.03 = 1 + (B/L)(Nq/Nc) Fqs = 1.03 = 1 + (B/L)tanǿ Fγs = 0.98 = 1 - 0.4(B/L)

Fcd = 1.09 = 1 + 0.4(D/B) if D/B ≤ 1 or = 1+ 0.4tan-1(D/B) if D/B > 1

Fqd = 1.07 = 1+2tanǿ(1-sinǿ)2(D/B) if D/B≤1 or =1+2tanǿ(1-sinǿ)2tan-1(D/B) if D/B>1

Fγd = 1

Fci = Fqi = 1.00 = (1 - β˚/90˚)2

Fγi = 1.00 = (1 - β/ǿ)2 q = 103.90 psf Correct for water table if d ≤ D, q = dγ + (D-d)(γsat - γw), else q =γdD γ = 37.60 pcf Correct for water table if d ≤ D, γ = γ' = γsat - γw if (d - D) ≤ B, γ = γ' + (d-D)/B * (γ - γ') qu = 4444 psf (qu = c'NcFcsFcdFci + qNqFqsFqdFqi+½γBNγFγsFγdFγi) qr = 2000 psf (qr = quΦbc)

Φbc = Bearing Capacity Resistance Factor, LRFD Table 10.5.5.2.2-1, = 0.45

Depth Factors (Hansen, 1970)

Inclination Factors (Hanna and Meyerhof, 1981)

Effective Surcharge & Unit Weight of Soil

General Bearing Capacity

BEARING CAPACITY CALCULATIONS

NORTH OF LAKE HARRIET DRAINAGE IMPROVEMENTS

Alder Ave (B-11) GEC Project No. 4518G

General Bearing Capacity Equation (Meyerhof, 1963) q u = c'N c F cs F cd F ci + qN q F qs F qd F qi +½γBN γ F γs F γd F γi

Bearing Capacity Factors

Shape Factors (De Beer, 1970)

B

D d Water Table β

APPENDIX E

CONSTRUCTION RECOMMENDATIONS

E. CONSTRUCTION RECOMMENDATIONS

The following sections include comments on issues related to the geotechnical aspects of the proposed construction. These recommendations are not intended to dictate construction methods or sequences. Instead, they are furnished as an aid to design professionals and to identify important construction issues related to foundation and earthwork plans and specifications. These recommendations may also be useful to personnel who observe construction activity.

Prospective contractors for this project should evaluate potential construction problems on the basis of their review of the contract documents, their own knowledge and experience in the local area, and on the basis of similar projects in other localities, taking into account their own proposed means and methods.

E.1 Groundwater and Surface Water Control

Depending on groundwater levels at the time of construction, excavation depths and final design grades, temporary…