Geotechnical_Report.pdf

SOILS AND FOUNDATION REPORT

NO. 03-12

PROJECT GREE 11(1)

STILL CREEK BRIDGE

GREENBELT NATIONAL PARK

PRINCE GEORGE’S COUNTY, MARYLAND

U.S. Department of Transportation Federal Highway Administration

Eastern Federal Lands Highway Division 21400 Ridgetop Circle

Sterling, VA 20166

August 2017

TABLE OF CONTENTS

1 INTRODUCTION

1.1 General

1.2 Project Description

2 REGIONAL GEOLOGIY

3 SUBSURFACE EXPLORATION AND CONDITIONS

3.1 Soil Sampling and Field Testing

3.2 Laboratory Testing

3.3 Subsurface Conditions

4 GEOTECHNICAL ANALYSES AND RECOMMENDATIONS

4.1 Bridge Foundation Alternatives

4.1.1 Deep Foundations

4.1.2 GRS-IBS Foundations

4.2 Design Analysis

4.2.1 Seismic Design Considerations

4.2.2 Bridge Loading

4.2.3 Geotechnical Design Parameters

4.2.4 Settlement

4.2.5 External Stability Analysis

4.2.6 Internal Stability Analysis

5 CONSTRUCTION CONSIDERATIONS

5.1 GRS-IBS General Construction Requirements

5.2 Excavation and Dewatering

5.3 GRS Foundation

5.4 GRS Facing

5.5 Reinforcement Length

5.6 Geosynthetics

6 DISCLAIMER/LIMITATIONS CLAUSE

APPENDICES

APPENDIX A – Figures APPENDIX B – Bridge Layout Plans APPENDIX C – Boring Location Map, Subsurface Profile, and Boring Logs APPENDIX D – Laboratory Test Data APPENDIX E – Design Calculations APPENDIX F – Representative Photographs

Note: Design changes subsequent to publication of this report and prior to the project’s advertisement will be documented by a memo inserted after the title page.

SOILS AND FOUNDATION REPORT

NO. 03-12

PROJECT GREE 11(1)

GREENBELT NATIONAL PARK

PRINCE GEORGE’S COUNTY, MARYLAND

1 INTRODUCTION

1.1 General

This report summarizes the results of our subsurface exploration, laboratory testing, and design analyses and presents our evaluations and recommendations for the replacement of a damaged culvert that carries Park Central Road over Still Creek. The site is located in Greenbelt National Park in Prince George’s County, Maryland. The site location map is provided in Figure 1, Appendix A.

1.2 Project Description

This project consists of replacing the corroded and damaged existing culvert at Still Creek with a bridge. The culvert consists of double corrugated metal arch with 10 feet span and 6 feet rise. Based on information provided by the National Park Service (NPS), the existing culvert was damaged by a large storm in June 2009 that caused water level in the stream to come within a foot or two from overtopping the road. A scour hole was observed at the culvert outlet during the field investigation.

It has been determined that a new bridge is an appropriate solution for the damaged and undersized structure. The proposed bridge will be single span concrete bridge of approximately 70 feet long and 32.5 feet wide. The elevation of the bridge surface will be approximately 4 to 5 feet higher than the current grade to improve the hydraulic capacity of the structure. The superstructure will consist of 8-AASHTO box beams BI-48 girder.

The bridge will be supported on Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS) abutments. The Bridge Layout Plans are provided in Appendix B.

2 REGIONAL GEOLOGIY

The Geologic Map of Maryland (Maryland Geologic Survey, 1968) indicates that the subject site is located in the Potomac Group of the Atlantic Coastal Plain Province. The Potomac Group consists primarily of interbeded Quartzose gravels; Protoquartzilic to Quartzilic Argillaceous sands; and white, dark and multicolored silts and clays. The site geological information for the project is shown in Figure 2, Geological Map in Appendix A.

3 SUBSURFACE EXPLORATION AND CONDITIONS

The Eastern Federal Lands Highway Division’s (EFLHD) Subsurface Exploration Team completed the drilling operation for this project in November 2011. The drilling

Project: GREE 11(1) Soils and Foundation Report Greenbelt National Park No. 03-12 Prince George’s County, Maryland Still Creek Bridge

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

STERLING, VA

operations included drilling two (2) soil borings (B-1 and B-2) in the vicinity of the proposed bridge abutments.

Borings B-1 and B-2 were drilled to the depths of 72 and 62 feet below existing grade, respectively, using the CME 750 ATV-mounted drill rig. Boring locations were determined in the field by measuring distances from features present on site and by a hand-held GPS. Boring elevations were determined from a topographic plan prepared by EFLHD Survey team. A boring location map and a generalized subsurface profile are provided in Appendix C.

3.1 Soil Sampling and Field Testing

Borings were advanced to their termination depths using 3¾-in. (inside diameter) hollow stem augers. Standard Penetration Testing (SPT) was performed using a 2¼-in. (outside diameter) split-spoon sampler in accordance with AASHTO T206-87. SPT soil samples were typically recovered at 2.5 and 5-foot intervals. Samples were obtained by driving the split-spoon sampler 24 inches into the undisturbed soil under the impact of a 140-lb.

automatic hammer free-falling 30 inches. The number of hammer blows required to advance the split-spoon sampler the middle foot of the 24-in. sample interval is designated as the “Standard Penetration Resistance” or N-value. The number of blows required to advance the sampler through each 6-in. interval was recorded on the field boring logs. A field description by color and texture was made for each recovered sample.

Representative portions of split-spoon samples were preserved in glass jars for laboratory testing. One (1) Shelby tube soil sample was collected in accordance with AASHTO T207, at Boring B-1. The undisturbed/thin-walled sample was preserved within its respective sample tube. All samples were later transported to EFLHD’s Materials Testing Laboratory in Sevierville, Tennessee for laboratory testing and storage. The sampling sequence and associated jar samples for each boring are presented on its appropriate Boring Log in Appendix C.

Water levels, if present, were measured at the time of completion of each boring and prior to backfilling the borehole. The borings were backfilled with auger cuttings upon completion of the drilling.

3.2 Laboratory Testing

Laboratory testing was conducted on representative soil samples recovered during the subsurface exploration to aid with the classification and evaluation of the engineering properties of soils present at the site. Laboratory tests included natural moisture content (AASHTO T-265), Atterberg limits (AASHTO T-89 & T-90), particle size analysis (AASHTO T-88), and classification (AASHTO M-145). All tests were conducted in general accordance with applicable ASTM/AASHTO standard test methods. The results of the laboratory testing program are presented in Appendix D and summarized in Table 1.

Table 1 – Summary of Laboratory Test Results

Boring No.

Sample No.

Sample Depth

(ft)

MC

Fines

LL

PI

B-1 J-6 13-16 16.2 12.5 * *

B-1 J-8 20-22 23.1 98.1 60 34

B-1 J-12 35-37 23.2 96.9 75 52

B-1 J-16 60-62 20.1 98.0 69 47

B-2 J-3 10-12 40.9 75.4 44 19

B-2 J-4 15-17 15.6 11.9 * *

B-2 J-8 28-30 25.6 98.5 59 32

B-2 J-12 45-47 17.9 97.2 65 40

* sample was not tested for the specific test

3.3 Subsurface Conditions

Boring logs describing the subsurface conditions encountered in each boring are provided in Appendix C. The Subsurface Profile in Appendix C represents the general soil conditions that may be encountered at the bridge abutments. Descriptions of the soil conditions encountered during the subsurface exploration conducted at the site are presented below. The stratification lines designating the interfaces between soil types on the boring logs in Appendix C represent approximate boundaries. The transition between materials may be gradual. It should be noted that one or more of the units may be absent at specific locations.

Borings B-1 and B-2 were drilled in the proximity of the proposed bridge abutments. In general, the borings encountered four basic soil types at various locations within the termination depths. Each of the soil types has been grouped according to its engineering properties and classification. These primary soil types are described briefly in the following paragraphs:

Fill – Fill material consisting of brown to reddish brown silty sand and clayey sand with trace amounts of gravel and organic matter was encountered from the ground surface to depths of 10.6 and 8 feet in Borings B-1 and B-2, respectively. SPT values recorded within this layer ranged from 5 to 21 blows per foot (bpf) in boring B-1 and 4 to 6 (bpf) in boring B-2.

Lean Clay – Brownish gray, lean clay was encountered in moist to wet condition below the fill to a depth of 14 feet in Boring B-2. The N-value recorded within this layer was 0 bpf (weight of hammer) indicating very soft conditions. This layer was not encountered in boring B-1.

Sand Silty Sand – Brown and orange silty sand to coarse grained sand with trace amounts of silt and clay were encountered in wet conditions in Boring B-1 below the fill and extended to about 16 to 17 feet below existing grade. Silty sand material was encountered in Boring B-2 below the lean clay layer and extended to 10.6 to 16 ft below existing site grade. with a N-value of 17 bpf. In B-2, this layer extends from 14 to 17 ft below existing site grade, with N-value of 20 bpf.

Fat Clay – Brownish red, stiff to hard fat clay was encountered in moist conditions below the sand layer to the boring termination depths at 72.0 ft and 62 ft in Borings B-1 and B- 2, respectively. N-values recorded within this layer ranged from 19 to 47 bpf in boring B- 1 and 16 to 39 bpf in Boring B-2.

Groundwater– Groundwater was encountered at depths of 11.5 ft and 11 ft below existing grade in Borings B-1 and B-2, respectively. These elevations are slightly lower than the water elevation in Still Creek. Groundwater level readings were made at the times and under the conditions stated on the boring logs. Fluctuations in groundwater level due to seasonal variations, rainfall, temperature, and other factors not evident at the time measurements were made should be expected.

4 GEOTECHNICAL ANALYSES AND RECOMMENDATIONS

4.1 Bridge Foundation Alternatives

Alternatives considered for the replacement of the existing culvert included bridge structure and bottomless box culvert. The bridge alternative was selected as it will restore the stream to a more naturally functioning ecosystem. Bridge foundations alternatives explored included deep foundations and GRS-IBS abutments. Foundations alternatives were evaluated based on performance, cost and constructability.

4.1.1 Deep Foundations

The results of the subsurface investigation at the site indicated very soft lean clay, medium dense sand, and stiff to hard fat clay at the bridge abutment locations. Therefore, deep foundation system consisting of driven piles embedded to depths ranging from 40 to 60 feet may be required to support the bridge through the soft soil strata. Therefore this alternative was deemed as not cost effective.

4.1.2 GRS-IBS Foundations

The GRS-IBS abutments consist of closely spaced layers of reinforced compacted fill and the super structure is placed directly on the geosynthetic reinforced soils (GRS) abutment. The benefits associated with the GRS-IBS abutment include:

1. The GRS foundation is relatively flexible compared to conventional bridge foundations resulting in uniform and therefore tolerable settlements.

2. GRS abutment and IBS approach are engineered to accommodate settlement allowing for smooth transition from the Bridge to the approach which helps eliminate the bump normally forms at the approach due to differential settlement.

3. The GRS-IBS is proven for significant cost savings of 20 to 60% compared to conventional bridge foundation.

4. The GRS-IBS is simple and easy to construct without the need of highly skilled labors and/or heavy or specialized equipment compared to conventional bridge foundation systems.

Therefore, the GRS-IBS was considered an ideal fit for this project.

4.2 Design Analysis

Design analysis performed for the GRS-IBS system included evaluation of the external stability (i.e., global stability, bearing resistance and direct sliding), internal stability (i.e., vertical capacity, deformation and reinforcement strength) and settlement. The design was performed in accordance with AASHTO LRFD Bridge Design Specifications, Fifth Edition, 2012 and Interim Revisions and FHWA-HRT-11-026 "Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide".

4.2.1 Seismic Design Considerations

AASHTO 4.7.4.2 indicates that seismic analysis is not required for single-span bridges regardless of seismic zone. However, connections between the bridge superstructure and the abutments shall conform to AASHTO 3.10.9.

4.2.2 Bridge Loading

Design parameters, provided by the Structural Engineer, are listed in Table 2.

Table 2 – Summary of Bridge Loading Data Bridge Width

(ft)

Abutment Width

(ft)

Total Service 1 (Un-factored)

(kip)

Total Strength 1 (Factored)

(kip)

32.4 41.2 460.3 658.5

4.2.3 Geotechnical Design Parameters

A summary of the design parameters used in the analyses and design of the GRS-IBS abutments, based on the subsurface profile encountered during our drilling operations are listed in Table 3. These parameters were determined based on empirical correlations for soils encountered, field SPT N-values, and laboratory test results.

Table 3 – Design Soil Parameters Soil Type Total

Unit Weight γ

(pcf)

Shear Strength Parameters

Water Table Depth

(ft)

(deg) c′ (psf)

Reinforced Soil 120 39 0

11.0

RSF 140 39 0

Foundation/Retained Soil -Layer 1 Medium dense sand

122 32 0

Retained Soil (silt sand and clay fill) 115 28 0 Foundation Soil -Layer 2 Medium stiff to hard clay

130 20 2000

RSF= Reinforced Soil Foundation; 'effectivefriction angle; c′= Effective (drained) cohesion

4.2.4 Settlement

Settlement analysis was performed for the GRS embankment using subsurface soil profile, bridge design data and published correlations with the soil index properties.

The result of the settlement analysis indicated an immediate settlement of less than 0.5 inch and total settlement of less than 2 inches. Most of the settlement is anticipated to take place during or not too long after completion of construction. Settlement computations are included in Appendix E.

4.2.5 External Stability Analysis

External stability analyses for the GRS abutment included sliding, bearing resistance, and overall global stability. Information regarding reinforcement length, abutment height, and foundation dimensions used for our analysis are listed in Table 4. A uniformly distributed load of 401.2 psf was applied to account for traffic surcharge.

Table 4 –GRS Abutment Dimensions and Reinforcement Lengths Abutment

Height

RSF

Width (front)

(ft)

RSF

Length (sides)

(ft)

RSF

Depth

Min. Base Length of Reinforcement

Design Bearing Width

11.1 43.7 12 2.5 9.5 4

The results of the external stability analyses are provided in Table 5. The results indicate that the proposed GRS abutment meets stability requirements for direct sliding and bearing resistance.

Table 5 –Summary of the External Stability Analysis Results Failure Mode Actual

CDR

Required

CDR

Direct Sliding (GRS-RSF interface) 1.3 1.0

Direct Sliding (RSF-Foundation soil interface) 1.2 1.0 Bearing Resistance 2.3 1.0

Global stability analysis was performed using ReSSA (3) computer program. A summary of the results is listed in Table 6. The analysis output is provided in Appendix E. The results indicate that the proposed GRS abutment meets or exceeds global stability requirements.

Table 6 –Summary of the Global Stability Analysis Results

Failure Mode Actual FS Required FS

Rotational 1.5 1.5

Translational 1.7 1.5

Three-part wedge failure mechanism 2.5 1.5

4.2.6 Internal Stability Analysis

Internal stability analysis to determine nominal capacity of GRS abutment was performed using the analytical method (soil-geosynthetic capacity method) described in FHWA- HRT-11-026 manual. The input characteristics and results of the analysis are presented in Table 7. The results indicate that the proposed GRS abutment satisfies vertical capacity requirements. The design calculations are provided in Appendix E. The maximum required reinforcement strength (Treq) was checked against the allowable reinforcement strength (Tallow) and the strength 2% tensile strain (T@=2%). The required reinforcement strength didn’t exceed the values of Tallow or T@=2% at any of the layers. Therefore, no bearing bed reinforcement is needed. However, the minimum requirement is that the bearing bed reinforcement should extend through five (5) courses of blocks. The calculations for the depth of bearing bed reinforcement is provided in Appendix E.

Table 7 – Results of Internal Stability Analysis based on the Analytical Method

Description Unit Value

Reinforcement vertical spacing (Sv) inches 8 Maximum particle size, inches (dmax) inches 1.0 Ultimate reinforcement strength (Tf) lb/ft 4,800 Factored Applied stress on top of GRS mass (Vapplied) psf 5,075 Factored ultimate capacity of the foundation using the analytical method (cap*qnan) psf 8,851

Ratio of factored ultimate capacity to factored applied pressure - 1.7 cap (resistance factor) =0.45

5 CONSTRUCTION CONSIDERATIONS

5.1 GRS-IBS General Construction Requirements

Construction procedures are outlined in Chapter 7 of the FHWA-HRT-11-026 "Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide".

(Adams, et al, 2012).

5.2 Excavation and Dewatering

In general, all temporary cut slopes constructed in soils should not be steeper than 1 horizontal to 1 vertical (1H:1V). All excavations are to be performed in accordance with applicable OSHA, federal, state, and county requirements and in accordance with Section 204 of the FP-14 Specifications. Temporary excavation in fill and/or natural material should be achievable using conventional earthmoving equipment in proper working condition. Any unsuitable materials encountered below proposed foundation elevations should be removed and replaced with suitable material.

Excavations should be kept dry at all times and control of storm or seepage water flowing into open excavations may be necessary in order to retain the integrity of the natural bearing soils. The contractor should control the flow of surface and seepage water into excavations at all times. Storm water collection and control during construction may be achieved using collection trenches and sumps, if accumulation does occur. All dewatering must be conducted in a manner that avoids undermining foundation subgrades and limits the pumping of fines.

5.3 GRS Foundation

The GRS foundation subgrades should not be left exposed to rain, flooding, or weathering conditions. It is recommended to place the geosynthetics reinforcement and select granular backfill immediately after excavation or to cover the GRS foundation subgrades with plastic during wet weather. It is not recommended to sub-excavate below the planned bottom of the GRS foundation.

5.4 GRS Facing

The CMU will insure compaction every 8-inch lift before placement of the next geosynthetic layer. The CMU should have a minimum compressive strength of 4,000 psi and water absorption limit of 5 percent.

5.5 Reinforcement Length

Extend reinforcement length as specified and provided in the plan.

5.6 Geosynthetics

Furnish geosynthetics consisting of geogrid or geotextile for the GRS abutment. Furnish geotextile for the RSF and integrated approach.

Geosynthetics material may be manufactured from Polypropylene (PP), High Density

Polyethylene (HDPE) or Polyester (PET).

Geosynthetics can be either uniaxial or biaxial. When a uniaxial type is used, the higher strength axis must be placed perpendicular to the wall face.

Furnish geosynthetic composed of a minimum ultimate tensile strength of 4,800 lb/ft according to ASTM D 4595 for geotextile or ASTM D 6637 for geogrid.

Geosynthetic reinforcement strength at 2 percent strain shall be greater than the unfactored required reinforcement strength.

6 DISCLAIMER/LIMITATIONS CLAUSE

The subsurface exploration procedures and results described in this report have been conducted in accordance with standard practices and procedures (except as specifically noted). The results of these explorations and tests represent conditions at the specific locations and dates indicated. Subsurface conditions between these locations may vary.

The design aanalyses and rrecommendations in this report include interpretations and recommendations developed by the Government in the process of preparing the design.

These interpretations are not intended as a substitute for the personal investigation, independent interpretation, and judgment of the Contractor.

Prepared by:

Mohammed Elias, Ph.D., P.E.

Senior Geotechnical Engineer

Reviewed by:

Mounir Abouzakhm, P.E.

Division Geotechnical Engineer

APPENDIX A

Figures

FIGURE 1

Site Location Map

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL LANDS HIGHWAY DIVISION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

STERLING, VIRGINIA

PROJECT

PRA-GREE 11(1)

STATE

MD

Project: PRA-GREE 11(1)

Source:

Geologic Map of Maryland (1968) Maryland Geologic Survey

FIGURE 2

Geologic Map

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL LANDS HIGHWAY DIVISION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

STERLING, VIRGINIA

STATE

MD

PROJECT

PRA-GREE 11(1)

Source:

CcC Christiana-Downer complex, 5 to 10 percent slopes

Soil Survey of Prince George's County, MD (2009) Web Soil Survey, USDA

STATE

MD

PROJECT

PRA-GREE 11(1)

FIGURE 3

Soil Survey Map

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL LANDS HIGHWAY DIVISION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

STERLING, VIRGINIA

Map Unit Symbol

ZS

SOD

Map Unit Name

Map Unit Legend

Zekiah and Issue soils, frequently flooded

Sassafras and Croom soils, 10 to 15 percent slopes

APPENDIX B

Bridge Layout Plans

NC MD GREE 11(1)

GREENBELT PARK

-J u l-

:1

P

M M

P r o j e c ts g r e e (1

B r id g e M ic r o s ta ti o n B r id g e

D e s ig n

F il e s

P

R O J E

C T

S .d g n

PROJECT TEAM LEADER BRIDGE DRAWING

of

DATESCALECHECKED BYDRAWN BYDESIGNED BYREVISIONSNO. DATE BY REVISIONS NO. DATE BY

STATE PROJECT

SHEET

NO.

U.S. DEPARTMENT OF TRANSPORTATION

REGION

BRP NO.

NPS

NO.

PMIS NO.

JJO/JEG B. OltmannJJO July 201310

NOT

FOR

CO

NST

RUCTI

ON

PRE

LIM

INARY

BRP-1132

-J u l-

:1

P

M M

P r o j e c ts g r e e (1

B r id g e M ic r o s ta ti o n B r id g e

D e s ig n

F il e s

P

R O J E

C T

S .d g n

REGION

SHEET

NO.

PROJECT TEAM LEADER BRIDGE DRAWING

DATESCALECHECKED BYDRAWN BYDESIGNED BYREVISIONSNO. DATE BY NO. DATE BY

PLAN AND ELEVATION

70’-0"

L

L RoadwayC

Elev. 80.38

Sta 102+97.52

Begin bridge

Elev. 80.59

Sta 103+67.60

End bridge

CL Structure

103+00

N

Bridge Length = 70’-0"

PLAN

ELEVATION

L

70’-0"

= 1’-0"16 3Scale:

= 1’-0"16 3Scale:

R03

3" = 1’-0"16

A C

T U

A L F I L E R

G R

E E P

E .D

G N of bridge at downstream face

Existing groundline groundline

Proposed culvert

Remove existing at 35’-0" left of C

Existing groundline at 40’-0" right C

Existing groundline

Type IV

Geotextile

Riprap Class 4

NC MD GREE 11(1)

STATE PROJECT

SHEET

NO.

REGION

NPS

PMIS NO.

PROJECT TEAM LEADERSCALECHECKED BYDRAWN BYDESIGNED BY

JJO/JEG B. OltmannJJO

GREENBELT PARK

BRIDGE DRAWING

DATE

U.S. DEPARTMENT OF TRANSPORTATION

BRP NO.

July 201310 BRP-1132

NOT

FOR

CO

NST

RUCTI

ON

PRE

LIM

APPENDIX C

Boring Location Map, Subsurface Profile, and Boring Logs

REG STATE PROJECT SHEET NO.

7. GEOPHYSICAL TEST SITE: SEISMIC RESISTIVITY

6. BHR - BORE HOLE REFUSAL

5. BHT - BORE HOLE TERMINATED

4. RQD - ROCK QUALITY DESIGNATION

3. CR% - PERCENT OF RECOVERY

2. R - REFUSAL, SPT 100 BLOWS/12"

1. SPT - STANDARD PENETRATION TEST - AASHTO T206-74 STERLING, VIRGINIA

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

CONDITIONS MAY VARY BETWEEN THESE LOCATIONS.

AT THE BORING LOCATIONS SHOWN. SUBSURFACE

THE SUBSURFACE CONDITIONS ENCOUNTERED

THE BORING LOGS ON THIS SHEET REPRESENT

AND SUBSURFACE PROFILE

BORING LOCATION PLAN

TYPE OF MATERIAL TEST BORING MISCELLANEOUS

SCALE

BORING NUMBER B-N

(24 HOURS)

WATER LEVEL (WL)

(TIME OF DRILLING)

WATER LEVEL (WL)

DEPTH MARKS

N BLOWS/12" (SPT)

J-N JAR SAMPLE NO.

CR% RQD

N

N N

N

BHT OR BHR

S R

SYMBOLTYPE OF MATERIALSYMBOL

STILL CREEK BRIDGE

NOT

FOR

CO

NST

RUCTI

ON

PRE

LIM

mm1671706m-883

L at 40’-0" rigth C

Existing groundline

L RoadwalC

Elev. 80.38

Sta 102+97.77

Begin bridge

Elev. 80.59

Sta 103+67.59

End bridge

CL Structure

103+00

N

Bridge Length = 70’-0"

PLAN

Lat 35’-0" left of C

Existing groundline to be removed

Existing calvert groundline

Proposed face of bridge at downstream

Existing groundline mm1671706m-883

LEAN CLAY

SILTY SAND

ST-1

0.00.0

10.6

16.0

72.0

28.0

0.0

8.0

14.0

17.0

62.0

Bridge Length = 70’-0"

FILL

FAT CLAY

B-1

B-2

SCALE IN FEET

0 10 20

GEOTECHNICAL REPORT NO. 03-12

PROJECT GREE 11(1)

SE MD GREE 11(1) 1 of 1

Elevation

SOIL BORING GENERAL NOTES

Drilling and Sampling Symbols

SS: Split Spoon - 1 3/8” I.D., 2” O.D., except where noted ST: Shelby Tube - 2” O.D., except where noted PA: Power Auger Sample

Water levels indicated on the boring logs are the levels measured in the boring at the times indicated. In pervious soils, the indicated elevations are considered reliable ground water levels. In impervious soils, the accurate determination of ground water elevations is not possible, even after several days, and additional evidence on ground water elevations must be sought.

VISUAL METHODS FOR SOILS CLASSIFICATION

Component Distinguishing Features

Boulders Larger than 12” (300 mm)

Cobbles 3” to 12” (75 mm to 12 mm)

Gravel Larger than No. 4 sieve and smaller than a 3” sieve, described with any of the following terms (or any combination):

Coarse 3” to 3/4” (75 mm to 19 mm) sieve Medium 3/4” to 3/8” (19 mm to 9.5 mm) sieve Fine 3/8” to No. 4 (9.5 mm to 4.75 mm) sieve

Sand The finest sand grains are just visible to the naked eye, while the largest would pass a No. 4

(4.75mm) sieve (pinhead size). Described with any of the following terms (or any combination):

Coarse No. 4 to No. 10 (4.75 mm to 2.0 mm) sieve Medium No. 10 to No. 40 (2.0 mm to 0.42 mm) sieve Fine No. 40 to No. 200 (0.42 mm to 0.075 mm) sieve

Silt 1. Lumps are easily crumbled when are-dried.

2. Feels gritty between the teeth.

3. A moist pat when shaken in the palm of the hand will appear shiny and wet. When squeezed it will appear dry and dull.

Clay 1. Lumps are comparatively hard when air-dried.

2. Threads (1/8” diameter) of considerable length will support their own weight when held by one end.

3. A moist pat will appear the same whether shaken in the palm of the hand or squeezed.

Order of Description

1. Soil Density (or consistency) – see table below

2. Color

3. Major Grain Size – Composes more than 50% of the sample

4. Modifying Term – “and” : 40% to 50% of the minor grain size

“some” : 30% to 40% “little” : 10% to 30%

“trace” : 10% or less

5. Minor Grain Size(s)

6. Other (plasticity, etc.)

7. Moisture Content (by field test) – “dry” : Absence of moisture, dusty, dry to the touch “moist” : Damp but no visible water

“wet” : Visible free water, usually soil is below water table

8. General Classification – Fill, Residual Soil, Weathered Rock

SOIL DENSITY (OR CONSISTENCY) TABLE

Coarse-Grained Soil (Gravel, Sand) Fine-Grained Soil (Clay, Silt)

Apparent Density SPT (# blows / ft) Consistency SPT (# blows / ft) Very loose 0-4 Very soft 0-2

Loose 5-10 Soft 3-4 Medium dense 11-30 Medium stiff 5-8

Dense 31-50 Stiff 9-15 Very dense >50 Very stiff 16-30

Hard >30

Examples:

1. Dense to very dense, brown to light brown, SILTY SAND, some gravel [A-7-6(10)]

(Moist)

-FILL-

Criteria for Describing Soil Structure

Description Criteria

Bed A sedimentary layer bounded by depositional surfaces.

Blocky A characteristic in which cohesive soil can be broken down into small angular lumps which resist further breakdown.

Bonded Attached or adhering.

Fissured Broken along definite planes of fracture.

Foliated Planar arrangement of textural or structural features.

Frequent More than one per foot of thickness.

Homogeneous Same color and appearance throughout.

Interbedded Alternating soil layers of different composition.

Laminae A very thin cohesive layer.

Layer A general term for material lying essentially parallel to the surfaces against which it was formed.

Lens A lenticular deposit, larger than a pocket.

Occasional One or less per foot of thickness.

Parting A very thin granular layer.

Pocket Small erratic deposits less than 12” in thickness.

Seam A thin layer separating two distinctive layers of different composition or greater magnitude.

Stratified Alternating layers of varying material or color.

Stratum A stratigraphic unit.

Varve A cyclic sedimentary couplet consisting of a coarser and a finer layer representing the variation in depositional energy resulting from the annual freeze-thaw cycle typically found in glaciolacustrine environments.

Loose to medium dense, brown,SILTY SAND, trace clay and gravel (moist)

[FILL]

Medium dense, brown, SILTY SAND, trace clay (wet)

Medium dense, orange, COARSE SAND, trace silt (wet)

Loose, brown and gray, SILTY SAND

Stiff, red, FAT CLAY (moist)

Very stiff to hard, red and gray, FAT CLAY (moist)

J-1

J-2

J-3

J-4

J-5

J-6

J-7

J-8

ST-1

J-10

10.6

12.5

15.0

16.0

28.0

1.25

3.25

3.0

4.0

1-2-3-4

2-4-4-4

1-3-3-2

3-9-12-7

4-7-10-7

3-3-4-3

1-5-7-10

5-13-18-25

1.4

1.5

1.6

1.6

1.6

0.5

1.4

1.4

1.8

(Blows / ft)

D ep th S ca le ft)

1. A bulk sample was collected from 5 to 10.5 feet.

2. Boring was backfilled with auger cuttings on 11/01/2011

SPT

Cool

Boring Began: 10/21/11

HSA

10/30/11

KT

RK/DHOperator:

North Abutment

U. S. DEPARTMENT OF TRANSPORTATION

Weather:

SAMPLE

hrs

Remarks:

Auger Cuttings UD

11.5

10 60

T yp e

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Plastic Limit Liquid Limit

40 80

MATERIAL DESCRIPTION

G ra ph ic

L og

Boring No.:

Hammer Wt. & Type:

Surface Elevation:

Water Content %

Inspector:Caved at:

Hammer Drop:

Project Name:

N o.

Park Central Road in Greenbelt National Park La ye r

D ep th ft)

Bridge on Still Creek

P P

/R Q

D (t sf

E le va tio n (f ee t)

Standard Penetration Test Data

Encountered at:

9.5 ftAfter

Groundwater Depth:

Project Location:

At Completion:

Completed:

Hole Diameter:

Boring Method:

Rock Core Diam:

Vane Shear

Boring Location:

30 in.

140 lbs/Auto 3 3/4

B lo w s pe r in

B-1

76.0 ft

Penetrometer

Sample Types:

Rock Core

R ec ft/

BORING LOG

B

O R

IN

G

L O

G

7/

/1

:2

M

P R

O

JE

C T

S \G

R E

E \1

1( 1)

\T E

C H

S E

R V

\G E

O T

E C

H \S

U B

S U

R F

A C

E I

N V

E S

T

IG

A T

IO

N

\B O

R

IN

G L

O G

S \G

R E

E

1(

B

L.

G

P J

65.4

63.5

61.0

60.0

48.0

Very stiff to hard, red and gray, FAT CLAY (moist) (Continued)

J-11

J-12

J-13

J-14

J-15

J-16

4.5

4.5

4.5

4.5

4.5

3-9-10-12

7-15-20-28

5-9-13-17

5-11-17-20

6-14-18-23

2.0

2.0

1.8

2.0

2.0

(Blows / ft)

D ep th S ca le ft)

1. A bulk sample was collected from 5 to 10.5 feet.

2. Boring was backfilled with auger cuttings on 11/01/2011

SPT

Cool

Boring Began: 10/21/11

HSA

10/30/11

KT

RK/DHOperator:

North Abutment

U. S. DEPARTMENT OF TRANSPORTATION

Weather:

SAMPLE

hrs

Remarks:

Auger Cuttings UD

11.5

10 60

T yp e

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Plastic Limit Liquid Limit

40 80

MATERIAL DESCRIPTION

G ra ph ic

L og

Boring No.:

Hammer Wt. & Type:

Surface Elevation:

Water Content %

Inspector:Caved at:

Hammer Drop:

Project Name:

N o.

Park Central Road in Greenbelt National Park La ye r

D ep th ft)

Bridge on Still Creek

P P

/R Q

D (t sf

E le va tio n (f ee t)

Standard Penetration Test Data

Encountered at:

9.5 ftAfter

Groundwater Depth:

Project Location:

At Completion:

Completed:

Hole Diameter:

Boring Method:

Rock Core Diam:

Vane Shear

Boring Location:

30 in.

140 lbs/Auto 3 3/4

B lo w s pe r in

B-1

76.0 ft

Penetrometer

Sample Types:

Rock Core

R ec ft/

BORING LOG

B

O R

IN

G

L O

/1

:2

M

P R

O

JE

C T

S \G

R E

E \1

1( 1)

\T E

C H

S E

R V

\G E

O T

E C

H \S

U B

S U

R F

A C

E I

N V

E S

T

IG

A T

IO

N

\B O

R

IN

G L

O G

S \G

R E

E

1(

B

L.

G

P J

Very stiff to hard, red and gray, FAT CLAY

Bottom of boring @ 72 ft

J-17

J-18

72.0

4.5

4.5

6-18-25-31

5-19-28-50

2.0

2.0

(Blows / ft)

D ep th S ca le ft)

1. A bulk sample was collected from 5 to 10.5 feet.

2. Boring was backfilled with auger cuttings on 11/01/2011

SPT

Cool

Boring Began: 10/21/11

HSA

10/30/11

KT

RK/DHOperator:

North Abutment

U. S. DEPARTMENT OF TRANSPORTATION

Weather:

SAMPLE

hrs

Remarks:

Auger Cuttings UD

11.5

10 60

T yp e

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Plastic Limit Liquid Limit

40 80

MATERIAL DESCRIPTION

G ra ph ic

L og

Boring No.:

Hammer Wt. & Type:

Surface Elevation:

Water Content %

Inspector:Caved at:

Hammer Drop:

Project Name:

N o.

Park Central Road in Greenbelt National Park La ye r

D ep th ft)

Bridge on Still Creek

P P

/R Q

D (t sf

E le va tio n (f ee t)

Standard Penetration Test Data

Encountered at:

9.5 ftAfter

Groundwater Depth:

Project Location:

At Completion:

Completed:

Hole Diameter:

Boring Method:

Rock Core Diam:

Vane Shear

Boring Location:

30 in.

140 lbs/Auto 3 3/4

B lo w s pe r in

B-1

76.0 ft

Penetrometer

Sample Types:

Rock Core

R ec ft/

BORING LOG

B

O R

IN

G

L O

/1

:2

M

P R

O

JE

C T

S \G

R E

E \1

1( 1)

\T E

C H

S E

R V

\G E

O T

E C

H \S

U B

S U

R F

A C

E I

N V

E S

T

IG

A T

IO

N

\B O

R

IN

G L

O G

S \G

R E

E

1(

B

L.

G

P J

4.0

Loose, red brown,CLAYEY SAND (moist to wet)

[FILL]

Very soft, brown and gray, LEAN CLAY (moist to wet)

Medium dense, brown, SILTY SAND, trace gravel (wet)

Very stiff to hard, red and brown, FAT CLAY (moist)

J-1

J-2

J-3

J-4

J-5

J-6

J-7

J-8

J-9

8.0

14.0

17.0

1.0

4.5

4.5

4.5

3.5

4.5

2-2-2-3

2-3-3-3

0-0-0-0

5-10-10-8

4-9-12-15

5-9-12-14

3-6-12-17

3-7-10-13

3-8-10-15

1.5

1.1

1.0

1.0

1.3

1.7

1.8

1.7

1.9

(Blows / ft)

D ep th S ca le ft)

Boring was backfilled with auger cuttings on 11/01/2011

SPT

Cool

Boring Began: 11/1/11

HSA

11/1/11

KT

RK/DHOperator:

South Abutment

U. S. DEPARTMENT OF TRANSPORTATION

Weather:

SAMPLE

hrs

Remarks:

Auger Cuttings UD

10 60

T yp e

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Plastic Limit Liquid Limit

40 80

MATERIAL DESCRIPTION

G ra ph ic

L og

Boring No.:

Hammer Wt. & Type:

Surface Elevation:

Water Content %

Inspector:Caved at:

Hammer Drop:

Project Name:

N o.

Park Central Road in Greenbelt National Park La ye r

D ep th ft)

Bridge on Still Creek

P P

/R Q

D (t sf

E le va tio n (f ee t)

Standard Penetration Test Data

Encountered at:

After

Groundwater Depth:

Project Location:

At Completion:

Completed:

Hole Diameter:

Boring Method:

Rock Core Diam:

Vane Shear

Boring Location:

30 in.

140 lbs/Auto 3 3/4

B lo w s pe r in

B-2

76.5 ft

Penetrometer

Sample Types:

Rock Core

R ec ft/

BORING LOG

B

O R

IN

G

L O

/1

:1

M

P R

O

JE

C T

S \G

R E

E \1

1( 1)

\T E

C H

S E

R V

\G E

O T

E C

H \S

U B

S U

R F

A C

E I

N V

E S

T

IG

A T

IO

N

\B O

R

IN

G L

O G

S \G

R E

E

1(

B

L.

G

P J

68.5

62.5

59.5

Very stiff to hard, red and brown, FAT CLAY

Bottom of boring @ 62 ft

J-10

J-11

J-12

J-13

J-14

J-15

62.0

3.5

4.5

4.5

4.5

3.75

4.5

4-6-10-12

3-9-11-13

4-11-15-19

5-10-13-13

5-11-14-19

8-16-23-25

2.0

2.0

1.9

1.9

1.9

1.9

(Blows / ft)

D ep th S ca le ft)

Boring was backfilled with auger cuttings on 11/01/2011

SPT

Cool

Boring Began: 11/1/11

HSA

11/1/11

KT

RK/DHOperator:

South Abutment

U. S. DEPARTMENT OF TRANSPORTATION

Weather:

SAMPLE

hrs

Remarks:

Auger Cuttings UD

10 60

T yp e

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

Plastic Limit Liquid Limit

40 80

MATERIAL DESCRIPTION

G ra ph ic

L og

Boring No.:

Hammer Wt. & Type:

Surface Elevation:

Water Content %

Inspector:Caved at:

Hammer Drop:

Project Name:

N o.

Park Central Road in Greenbelt National Park La ye r

D ep th ft)

Bridge on Still Creek

P P

/R Q

D (t sf

E le va tio n (f ee t)

Standard Penetration Test Data

Encountered at:

After

Groundwater Depth:

Project Location:

At Completion:

Completed:

Hole Diameter:

Boring Method:

Rock Core Diam:

Vane Shear

Boring Location:

30 in.

140 lbs/Auto 3 3/4

B lo w s pe r in

B-2

76.5 ft

Penetrometer

Sample Types:

Rock Core

R ec ft/

BORING LOG

B

O R

IN

G

L O

/1

:1

M

P R

O

JE

C T

S \G

R E

E \1

1( 1)

\T E

C H

S E

R V

\G E

O T

E C

H \S

U B

S U

R F

A C

E I

N V

E S

T

IG

A T

IO

N

\B O

R

IN

G L

O G

S \G

R E

E

1(

B

L.

G

P J

14.5

APPENDIX D

Laboratory Test Data

SOIL DATA

USCSDESCRIPTION

DEPTHSAMPLE

SOURCESYMBOL

Project No.:

Project:

Client:

Particle Size Distribution Report

P E

R C

E N

T F

IN

E

R

100 10 1 0.1 0.01 0.001200 GRAIN SIZE - mm

% + 3"

% GRAVEL

CRS. FINE

% SAND

CRS. MEDIUM FINE

% FINES

SILT CLAY

in in in

1- 1/ in in

3/ in

1/ in

3/ in

#4 #1

#2

#3

#4

#6

#1

#1

#2

0.0 5.0 13.3 10.8 36.0 22.4 12.5

(ft.)

GREE 11(1)

GREE 11(1)

FHWA / EFLHD

Sill Creek B-1/J-6 13-16

Particle Size Distribution Report

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

0.0 0.0 0.2 0.0 0.4 1.3 98.1

Sill Creek B-1/J-8 20-22

0.0 0.0 0.0 0.0 0.4 2.7 96.9

Sill Creek B-1/J-12 35-37

0.0 0.0 0.0 0.0 0.5 1.5 98.0

Sill Creek B-1/J-16 60-62

0.0 0.0 0.0 0.0 8.6 16.0 75.4

Sill Creek B-2/J-3 10-12

USCSDESCRIPTION

DEPTHSAMPLE

SOURCESYMBOL

Project No.:

Project:

Client:

Particle Size Distribution Report

P E

R C

E N

T F

IN

E

R

100 10 1 0.1 0.01 0.001200 GRAIN SIZE - mm

% + 3"

% GRAVEL

CRS. FINE

% SAND

CRS. MEDIUM FINE

% FINES

SILT CLAY

in in in

1- 1/ in in

3/ in

1/ in

3/ in

#4 #1

#2

#3

#4

#6

#1

#1

#2

0.0 6.0 23.1 10.9 30.7 17.4 11.9

(ft.)

GREE 11(1)

GREE 11(1)

FHWA / EFLHD

Sill Creek B-2/J-4 15-17

Particle Size Distribution Report

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

0.0 0.0 0.0 0.0 0.2 1.3 98.5

Sill Creek B-2/J-8 28-30

0.0 0.0 0.0 0.0 1.9 0.9 97.2

Sill Creek B-2/J-12 45-47

INDEXLIMITLIMITCONTENTNO.

PLASTICITYLIQUIDPLASTICWATERDEPTHSAMPLE

NATURAL

SOURCESYMBOL

Project No.:

Project:

Client:

LIQUID AND PLASTIC LIMITS TEST REPORT

(ft.)

AASHTO

GREE 11(1)

GREE 11(1)

FHWA / EFLHD

34602623.120-22B-1/J-8Sill Creek

LIQUID AND PLASTIC LIMITS TEST REPORT

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

52752323.235-37B-1/J-12Sill Creek

47692220.160-62B-1/J-16Sill Creek

19442540.910-12B-2/J-3Sill Creek

32592725.628-30B-2/J-8Sill Creek

10 30 50 70 90 110

LIQUID LIMIT

P

LA

S T

IC

IT

Y

IN

D E

X

PI

=L

L-

A-4 or A-2-4 A-5 or A-2-5

A-7-6

A-6 or A-2-6

A-7-5 or A-2-7

INDEXLIMITLIMITCONTENTNO.

PLASTICITYLIQUIDPLASTICWATERDEPTHSAMPLE

NATURAL

SOURCESYMBOL

Project No.:

Project:

Client:

LIQUID AND PLASTIC LIMITS TEST REPORT

(ft.)

AASHTO

GREE 11(1)

GREE 11(1)

FHWA / EFLHD

40652517.945-47B-2/J-12Sill Creek

LIQUID AND PLASTIC LIMITS TEST REPORT

FEDERAL HIGHWAY ADMINISTRATION

EASTERN FEDERAL LANDS HIGHWAY DIVISION

10 30 50 70 90 110

LIQUID LIMIT

P

LA

S T

IC

IT

Y

IN

D E

X

PI

=L

L-

A-4 or A-2-4 A-5 or A-2-5

A-7-6

A-6 or A-2-6

A-7-5 or A-2-7

APPENDIX E

Design Calculations

Date: 07/27/2017 Calcs: M. Elias Checked: M. Abouzakhm

Project - GREE 11(1) Greenbelt Park Still Creek Bridge Design of GRS-IBS

Design Specificatrions:

1. AASHTO LRFD Bridge Design Sepcifications, 2014

2. FHWA-HRT-11-026 "Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide"

Habut 11.09 ft Height of GRS abutment hrb 2.75ft Height of roadbase = height of bridge beam+deck

Bb 32.438ft Bridge width

Lspan 70ft Bridge span ab 8in Distance between the back of the wall face and beam seat (set back)

Labut 41.17 ft Abutment width

Lblock 15.625in Length of a facing block bblock 7.625in Width of a facing block hblock 7.625in Height of a facing block

Wblock 42lbf Weight of individual block

Nblck_est

Habut hblock

17.453 Estimated number of CMU blocks layers

Actual number of CMU blocks layers Nblock floor Nblck_est 17

Total Ultimate reinforcement strength Tf 4800plf

Sv 8in Reinforcement vertical spacing

Pdbp 4000.psf Design bearing pressure-FHWA-HRT-11-026 (page 25)

Dist. from top of wall Factored Unfactored Factored Ultimate Check Unfactored 2% Check No. Layer z (ft) α β σh,bridge (psf) σh,bridge,f (psf) σh,rb (psf) σh,rb,f (psf) σh,t (psf) σh,t,f (psf) σh,W (psf) σh,W,f (psf) σh,total,f (psf) σh,total (psf) Treq,f (lb/ft) Treq,f > Tf,f Treq (lb/ft) Treq >T@2%

1.0 1.0 0.6 2.53 -1.26 621 866 88 118 91 160 17 27 1171 817 1256 YES 876 YES

2.0 2.0 1.3 2.01 -1.00 583 813 88 118 91 160 35 55 1146 796 1229 YES 854 YES

3.0 3.0 1.9 1.62 -0.81 523 730 88 118 91 160 52 82 1090 754 1170 YES 809 YES

4.0 4.0 2.5 1.33 -0.67 461 643 88 118 91 160 69 109 1031 709 1105 YES 761 YES

5.0 5.0 3.2 1.12 -0.56 405 565 88 118 91 160 87 137 980 671 1051 YES 719 YES

6.0 6.0 3.8 0.97 -0.48 358 499 88 118 91 160 104 164 941 641 1009 YES 687 YES

7.0 7.0 4.4 0.85 -0.42 319 445 88 118 91 160 121 191 914 619 980 YES 664 YES

8.0 8.0 5.1 0.75 -0.37 286 399 88 118 91 160 139 219 896 604 961 YES 648 YES

9.0 9.0 5.7 0.67 -0.34 259 362 88 118 91 160 156 246 886 594 950 YES 637 YES

10.0 10.0 6.4 0.61 -0.30 236 330 88 118 91 160 173 273 881 589 945 YES 632 YES

11.0 11.0 7.0 0.56 -0.28 217 303 88 118 91 160 191 301 882 587 946 YES 630 YES

12.0 12.0 7.6 0.51 -0.26 201 280 88 118 91 160 208 328 886 588 950 YES 630 YES

13.0 13.0 8.3 0.48 -0.24 186 260 88 118 91 160 226 355 893 591 958 YES 634 YES

14.0 14.0 8.9 0.44 -0.22 174 243 88 118 91 160 243 383 903 596 969 YES 639 YES

15.0 15.0 9.5 0.41 -0.21 163 228 88 118 91 160 260 410 915 602 982 YES 646 YES

16.0 16.0 10.2 0.39 -0.19 153 214 88 118 91 160 278 437 929 610 997 YES 654 YES

17.0 17.0 10.8 0.37 -0.18 145 202 88 118 91 160 295 464 945 619 1013 YES 664 YES

18.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

19.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

20.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

21.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

22.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

23.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

24.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

25.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

26.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

27.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

28.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

29.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

30.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

31.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

32.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

33.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

34.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

35.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

36.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

37.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

38.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

39.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

40.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

41.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

42.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

43.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

44.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

45.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

46.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

47.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

48.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

49.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

50.0 End of reinforcement layers - - - - - - - - - - - - - - - - -

Equivalent Bridge Load Road Base DL and Approach LL GRS Fill

Check for GRS-IBS Abutment Geometry :

demin 3in 0.02 Habut 3inif

0.02 Habut otherwise

Minimum clear space (from top of wall to bottom of superstructure) = Max (2% abutment height, 3") de demin 3 in Design clear space

H Habut de 11.34 ft Height of GRS abutment including clear space distance (de) bmin 2ft Lspan 25.ftif

2.5ft otherwise

Minimum bearing width bmin 2.5 ft

Design bearing width b 4ft

Btotalmin max 5ft 0.3 H( ) Lspan 25.ftif max 6ft 0.3 H( ) otherwise

Minimum base width

Btotalmin 6 ft

Btotal 9.5ft Design base width

B Btotal bblock 8.865 ft Base length of reinforcement not including the GRS facing

BRSFmin 1.25 Btotal 11.875 ft Minimum width of reinforced soil foundation

BRSF 12 ft Design width of reinforced soil foundation xRSF.min BRSF Btotal 2.5 ft Minimum length of RSF in front of the GRS facing xRSF 2.5ft Design length of RSF in front of the GRS facing

DRSFmin 0.25 Btotal 2.375 ft Minimum depth of excavation should be below scour depth

DRSF 2.5ft Design depth of excavation (RSF depth) br.min 2 ab b 5.333 ft Minimum length of bearing bed reinforcement br 6.5ft brb Btotal ab bblock b 4.198 ft Distance over which the road base DL and roadway LL surcharges act over the GRS

L oad and Resistance Factors:

γDCMAX 1.50 Maximum load factor for dead load (DL) γDCMIN 0.9 Minimum load factor for dead load (DL) γDCMAX_CA 1.25 Maximum load factor for dead load for component and attachment (DL) γDCMIN_CA 0.9 Minimum load factor for dead load for component and attachment (DL) γEHMAX 1.5 Maximum load factor for horizontal earth pressure γEHMIN 0.9 Minimum load factor for horizontal earth pressure γESMAX 1.5 Maximum load factor for earth surcharge γESMIN 0.75 Minimum load factor for earth surcharge γEVMAX 1.35 Maximum load factor for vertical earth pressure γEVMIN 1.0 Minimum load factor for vertical earth pressure γLS 1.75 Load factor for live load (LL) surcharge

Φτ 1 Resistance factor for shear resistance along common interfaces

Φb 0.65 Resistance factor for bearing resistance

Φcapan 0.45 Resistance factor for ultimate capacity

Soil Properties:

γw 62.4pcf Unit weight of water

Foundation Soil:

γf 122pcf Unit weight for foundation soil γfe γf γw 59.6 pcf Effective unit weight for foundation soil ϕfe 32deg Effective angle of internal friction for foundation soil, degrees cfe 0psf Effective cohesion for foundation soil

Retained Soil:

γb 115pcf Unit weight for retained soil

Effective angle of internal friction for retained soil, degrees ϕbe 28deg cbe 0psf Effective cohesion for retained soil

GRS (Reinforced) Soil Properties:

Unit weight for reinforced soil γr 120pcf ϕr 39deg Angle of internal friction for reinforced soil, degrees cr 0.psf Effective cohesion for reinforced soil dmax 1.0in Miximum particle size

RSF & Road Base Soil Properties:

γrb 140pcf Unit weight for road base/RSF soil γrbe γrb γw 77.6 pcf Effective unit weight for RSF soil ϕrb 39deg Angle of internal friction for road base/RSF soil, degrees crb 0.psf Undrained shear strength for road base/RSF soil

Cofficients of Earth Pressure:

Kaf

1 sin ϕfe 1 sin ϕfe 0.307 Coefficient of active earth pressure for foundation soil

Coefficient of passive earth pressure for the foundation soil in front of the RSFKpfe

1 sin ϕfe 1 sin ϕfe 3.255

Kab

1 sin ϕbe 1 sin ϕbe 0.361 Coefficient of active earth pressure for retained backfill soil

Kar

1 sin ϕr 1 sin ϕr 0.228 Coefficient of active earth pressure for the reinforced soil

Kpr

1 sin ϕr 1 sin ϕr 4.395 Coefficient of passive earth pressure for the backfill soil in front of the wall

Karb

1 sin ϕrb 1 sin ϕrb 0.228 Coefficient of active earth pressure for the road base and RSF soil

Bridge Loading

Total bridge dead load reaction at bearing per abutment Data provided by BridgeBRIDGE_DL 294.1kip

BRIDGE_LL 166.2kip Total bridge live load reaction at bearing per abutment Data provided by Bridge qb

BRIDGE_DL

b Bb

2.267 10 psf Pressure from Bridge DL qLL

BRIDGE_LL

b Bb

1.281 10 psf Pressure from Bridge LL qrb hrb γrb 385 psf Road base dead load

Wgrs B H γr 12062.925 plf Weight of the GRS abutment backfill

WRSF BRSF DRSF γrbe 2.328 10 plf Weight of the RSF

Wface Nblock

Wblock

Lblock

548.352 plf Weight of the facing element

Surcharge Loading - AASHTO Table 3.11.6.4-1

RW_Height ft heqAASHTO ft

Equivalent height of overburden for traffic surchargeheq linterp RW_Height heqAASHTO H 2.87 ft

Roadway live load (LL) qt heq γrb 401.2 psf

Check bearing pressure:

The bearing stress on the GRS abutment should not exceed 4,000 psf FHWA-HRT-11-26,Section 4.1

Pabp qb qLL 3547.5 psf Ok (Pabp Pdbp )

Pdbp 4000 psf

External Stability Analyses :

Direct Sliding z 2 cbe γb Kab 0 ft

Fb

Kab γb H 2 Kab cbe H z( ) 2.67 10 plf Lateral active earth force

Frb Kab qrb H 1576.2 plf Lateral force due to roadbase surcharge

Ft Kab qt H 1642.7 plf Lateral force due to traffic surcharge

Check Direct Sliding at the interface between the GRS Abutment and RSF

FR1 γEHMAX Fb γESMAX Frb γLS Ft 9243.5 plf

Factored driving force for direct sliding calculation

WtR γEVMIN Wgrs γDCMIN Wface γDCMIN qb b γEVMIN qrb brb 22332.5 plf

Factored total resisting weight (weight of GRS plus weight of Bridge beam plus weight of the road base over the GRS mass only) μ tan ϕr 0.54 Friction factor (coefficient of friction) based on interface friction angle between the reinforced fill and the geosynthetic for the RSF

RR Φτ WtR μ 12056.3 plf Factored resisting force

CDRs

RR

FR1

1.3 Ok (CDR> 1.0) Capacity demand ratio for direct sliding resistance

Check Direct Sliding at the interface between the RSF and the Foundation Soil

FR2 γEHMAX Fb γESMAX Frb γLS Ft 9243.5 plf Factored driving force at the RSF-foundation soil interface for direct sliding calculation

Factored total resisting weight (weight of GRS plus weight of Bridge beam plus weight of the road base over the GRS mass and RSF mass only)

WtR2 WtR γEVMIN WRSF 24660.5 plf

Pp DRSF

Kpfe γfe DRSF 2 Kpfe cfe

606.167 plf

Lateral passive earth force

Friction factor (coefficient of friction) based on interface friction angle between the RSF geosynthetic and foundation soil.μ2 tan ϕfe 0.417

RR2 Φτ WtR2 μ2 cfe BRSF γEHMIN Pp 10818.6 plf

Factored resisting force at the RSF- foundation soil interface

CDRs2

RR2

FR2

1.17 Ok (CDR> 1.0) Capacity demand ratio for direct sliding

resistance at the RSF- foundation soil interface

Bearing Resistance

ΣMD γEHMAX Fb H γESMAX Frb γLS Ft

44842.3 lbf

Driving moments

ΣMR γDCMAX_CA qb b γLS qLL b

BRSF

b ab xRSF bblock γLS qt brb γEVMAX qrb brb

BRSF

brb γEVMAX Wgrs

B

49558.1 lbf

Resisting moments

ΣV γEVMAX Wgrs γEVMAX WRSF γDCMAX_CA Wface γLS qt brb γEVMAX qrb brb γDCMAX_CA qb b γLS qLL b

4.554 10 plf

Total vertical load eBn

ΣMD ΣMR

ΣV

ΣMD ΣMR

ΣV

0.ftif

0ft otherwise

Eccentricity of the resulting base force at the base of the RSF, ft eBn 0 ft σvbase

ΣV

BRSF 2eBn

3795.183 psf Applied vertical pressureand traffic surcharge

AASHTO Table 10.6.3.1.2a-1: Bearing Capacity Factors Nc (Prandtl, 1921), Nq (Reissner, 1924), and Nγ (Vesic, 1975) - Correction factors are ignored.

For ϕfe=32 deg.

Nc 35.5 Nq 23.2 Nγ 30.2

Bef BRSF 2 eBn 12 ft Effective foundation width ic 1 iq 1 iγ 1 Inclination correction factors - No inclined load assumed dq 1 Depth correction factor (assumed)

Dw DRSF Depth to groundwater table

Cwq 1.0 Cwγ 1.0 Correction factors for location of G.W.T, AASHTO Table 10.6.3.1.2a-2 sc 1

Labut

Nq

Nc

1.19 sq 1

BRSF

tan ϕfe

1.182 Shape correction factors for ϕf>0, AASHTO Table 10.6.3.1.2a-3 sγ 1 0.4

0.883

Nominal Bearing Resistance Equation: AASHTO 10.6.3.1 qn cfe Nc sc ic γfe DRSF Nq sq dq iq Cwq 0.5 γfe Bef Nγ sγ iγ Cwγ 13626.805 psf

Nominal bearing resistance qfbrst Φb qn 8857.4 psf Factored bearing resistance

Capacity demand ratio for bearing resistance CDRbr qfbrst σvbase

2.33 Ok (CDR> 1.0)

Internal Stability Analysis:

Vertical Capacity - Analytical Method

Nominal load-carrying capacity of the foundation using the analytical methodqnan 0.7

Sv

6 dmax

Tf

Sv

Kpr 1.967 10 psf

Vapplied γDCMAX_CA qb γLS qLL 5.075 10 psf Factored applied stress on top of GRS mass

Ratio of factored vertical resistance to…