Attachment 18. UPRR Requirements & Guidelines.pdf

UPRR Requirements and Guidelines

Various Exhibit A Forms

(required for all temporary crossings under tracks and closest encroachment to centerline of track)

SUBDIVISION:

M.P.:

E.S.M.:

NEAREST CITY: COUNTY: STATE:

APPLICANT:

FILE NO.: DATE:

SCALE:

SECTION

NONE

CASING PIPE

CARRIER PIPE

SURFACE

GROUND

CROSSING

ANGLE OF

DEG.

UPRR R.O.W.

UPRR R.O.W.

R

O

W

U P

R R

R

O

W

U P

R R

A

PLAN

SCALE: NONE

TRACK

‘ OUTER

TRACK

‘ OUTER

VENT PIPE

T R

A C

K

C

O S

S I

N G

P I

E

L

N E

A

A

DITCH

DRAINAGE

____FT.

____ FT.

____FT. ____FT.

____FT.

____FT.

____FT.

____FT.

TOTAL TRACKS

____FT. ____FT.

____FT. ____FT.

F T

F T

NORTH ARROW

CROSSING TRACK

FIXED OBJECT

DESCRIBE

TRACK TYPE:

LAT.:

LONG.:

____ FT.

____FT.

U

M

L

E P

O S

T

CROSSING TRACK

FIXED OBJECT

DESCRIBE

U

M

L

E P

O S

T

ENCROACHMENT

LONGITUDINAL PIPE

EXHIBIT "A"

BOTH

ENCROACHMENT

CROSSING

PIPELINE

NON-FLAMMABLE LIQUID

2) REFER TO AREMA VOLUME 1, CHAPTER 1, PART 5, SECTION 5.3.

1) ALL DIMENSIONS MEASURED PERPENDICULAR TO THE CENTERLINE OF TRACK.

NOTES:

_______ AND _______.

BORING AND JACKING PITS WHEN MEASURED AT RIGHT ANGLES

F) DISTANCE FROM CENTERLINE OF TRACK TO NEAR FACE OF

CASING PIPE IS ______ AT THE ENDS.

CATHODIC/COATING PROTECTION_______

WALL THICKNESS ______ IN. DIAMETER ______ IN.

TOTAL LENGTH CASING PIPE: ______ FT.

E) CASING MATERIAL __________________________. IF RCP, CLASS V? ____.

CATHODIC/COATING PROTECTION_______

WALL THICKNESS (INCH)/ SCHEDULE _________ . DIAMETER ______ IN.

OPERATIONAL PRESSURE ______ PSI. MAOP ______ PSI.

COMMODITY TO BE CONVEYED _____________________.

D) CARRIER MATERIAL ________________________. IF RCP, CLASS V? ____.

C) SIGNS PROVIDED? ______.

B) DIST. FROM CENTERLINE OF TRACK TO PIPE ENCROACHMENT _____.

A) METHOD OF INSTALLATION ____________________________________

Guidelines for Temporary Shoring

GUIDELINES FOR

TEMPORARY SHORING

EMAIL BEFORE YOU DIG

UP.COM/CBUD

EMERGENCIES

1-888-877-7267

CALL BEFORE YOU DIG

1-800-533-2891

EMERGENCIES

1-800-832-5452

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 1

Contents

1. INTRODUCTION

PURPOSE

SCOPE

2. GENERAL CRITERIA

SAFETY & RAILROAD OPERATIONS

SHORING REMOVAL

RAILROAD FLAGGING

CALL BEFORE YOU DIG & EXISTING UTILITIES

APPLICANT & CONTRACTOR RESPONSIBILITIES

TRACK, GROUND & SHORING MONITORING:

RAILROAD RIGHT-OF-WAY

CONSTRUCTION AND MAINTENANCE AGREEMENT

RAILROAD REVIEW PROCESS

APPROVAL EXPIRATION

3. DESIGN

GENERAL DESIGN REQUIREMENTS

INFORMATION REQUIRED

DESIGN PROCEDURE

(Step 1) EXCAVATION LOCATION

(Step 2) SUBSURFACE CHARACTERIZATION

(Step 3) SHORING TYPES

(Step 4) APPLIED LOADS AND CALCULATIONS

(Step 5) STRUCTURAL DESIGN CALCULATIONS

DESIGN PLAN REQUIREMENTS

4. DEFINITIONS

5. APPENDIX

LIVE LOAD PRESSURE DUE TO COOPER E80 LOADING

CHART – LIVE LOAD PRESSURE DUE TO E80 LOADING

TABLES FOR SOIL SPECIFICATIONS

6. REFERENCES

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 2

1. INTRODUCTION

PURPOSE

a. The purpose of these guidelines is to inform public agencies, design engineers, contractors and inspectors of current Railroad standards and requirements concerning design and construction of temporary shoring.

SCOPE

a. This guideline governs on the Railroad Right-of-Way. This includes the limits of property owned, controlled and/or operated upon by the Railroad.

b. All requirements addressed within this document shall constitute minimum requirements for all projects or works on the Railroad Right-of-Way. The applicability of each requirement for any given project will be subjected to the Railroad’s discretion.

c. Where laws or orders of authority prescribe a higher degree of protection or restriction than specified herein, the higher degree so prescribed shall control.

d. These guidelines supplement the current American Railway Engineering and Maintenance-of-Way

Association (AREMA) Manual for Railway Engineering. For items covered within these guidelines and

AREMA, the more restrictive shall control.

i. It is the requirement for the Contractor and designer developing Railroad shoring systems to have a copy of the AREMA Manual. Visit www.arema.org to obtain the Manual for Railway

Engineering.

e. These guidelines supersede all previous Railroad guidelines for temporary shoring and are subject to revision without notice.

f. In addition to this guideline, all excavations shall also be governed by each individual Railroad requirements, Federal, State and Local laws, rules and regulations concerning construction safety.

g. These guidelines are provided as a reference and cannot be taken as authority to construct without prior review and written approval of the Railroad. See Section 2.9 for review process.

2. GENERAL CRITERIA

SAFETY & RAILROAD OPERATIONS

a. Projects shall be designed such that construction activities and phasing will not compromise safety nor impact Railroad operations.

b. Emergency Railroad phone numbers are to be obtained from a Railroad representative prior to the start of any work and shall be posted at the job site.

SHORING REMOVAL

a. The Contractor is responsible for planning and executing all procedures necessary to construct, maintain and remove the temporary shoring system in a safe and controlled manner.

RAILROAD FLAGGING

a. A flagman is required when any work is performed within 25 feet of track centerline. If the Railroad provides flagging or other services, the Contractor shall not be relieved of any responsibilities or liabilities as set forth in any document authorizing the work. No work is allowed within 50 feet of track centerline when a train passes the work site, and all personnel must clear the area within 25 feet of track centerline and secure all equipment when trains are present.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 3

CALL BEFORE YOU DIG & EXISTING UTILITIES

a. Call Before You Dig: Appropriate measures for the installation and protection of fiber optic, or other cables, shall be addressed in the plans and contract documents. For specific Railroad requirements and additional information refer to:

BNSF: www.bnsf.com or call 1-800-533-2891.

UPRR: www.up.com/cbud

b. Relocation of utilities or communication lines not owned by the Railroad shall be coordinated with the respective utility owners. Utility relocation plans must then be submitted to the Railroad utility representative(s) for review and prior approval must be secured before work can proceed. The Railroad will not be responsible for costs associated with any utility, signal, or communication line relocation or adjustments.

c. Abandonment of utilities must follow the UPRR Guidelines For Abandonment of Subsurface Utility

Structures or the BNSF Utility Accommodation Policy.

APPLICANT & CONTRACTOR RESPONSIBILITIES

a. The Applicant and Contractor must verify with the Railroad’s Local Representative their receipt of the latest version of these guidelines prior to developing Construction Documents.

b. Construction shall NOT impact Railroad operations, functions and facilities:

i. The Applicant and Contractor shall develop design plans, including, without limitation, all procedures necessary to construct and maintain the proposed shoring project, which cause no interruption to

Railroad operations during and after construction.

ii. Work shall also not impede drainage or other functions of the Railroad.

iii. Any rail traffic outages or curfews thought to be required for the installation or removal of any portions of a shoring system must be requested by submittal to the Railroad for prior consideration long in advance of mobilization and construction. Such requests may not be granted.

iv. Unapproved and unscheduled interruptions to Railroad operations may result in your removal from

Railroad Right-of-Way, and your authorization to re-enter revoked.

c. Railroad approved design and construction plans:

i. The Contractor shall install the temporary shoring system per the plans approved by the Railroad.

ii. Any deviation from the Railroad approved plans requires resubmittal and prior approval by the

Railroad prior to proceeding with said deviation. Approval from the Railroad may not be granted.

d. The Contractor must monitor the track, ground and shoring for movement. See Section 2.6 for monitoring.

e. The Applicant and Contractor shall be jointly responsible for the design, construction and performance of the temporary structure.

f. The Contractor must review the temporary shoring plans to ensure that the proposed method of construction is compatible with the existing site and soil conditions. Removal of the shoring system must also be addressed.

g. The Contractor must obtain a valid right of entry permit from the Railroad and comply with all Railroad requirements when working on Railroad property.

h. The Contractor is responsible to protect the Railroad ballast and subballast from contamination.

i. The Contractor shall comply with all State and Federal Laws, county or municipal ordinances and regulations which in any manner affect the work.

j. All removed soils will become the responsibility of the Contractor and shall be disposed of outside the

Railroad Right-of-Way according to the applicable Federal, State and Local regulations.

http://www.bnsf.com/ https://www.up.com/aboutup/community/telecom/groups/index.htm https://www.up.com/cs/groups/public/@uprr/@realestate/documents/up_pdf_nativedocs/pdf_up_util_aban.pdf https://www.up.com/cs/groups/public/@uprr/@realestate/documents/up_pdf_nativedocs/pdf_up_util_aban.pdf https://www.bnsf.com/bnsf-resources/pdf/about-bnsf/utility.pdf

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 4

k. The project engineer and the Contractor shall evaluate the quality of materials furnished and work performed.

l. The Applicant, at its expense, shall be solely responsible for all costs, design, construction, future replacement, maintenance, and serviceability of the proposed shoring project, except as noted otherwise in the Construction & Maintenance (C & M) Agreement with the Railroad.

m. The Applicant shall be responsible for obtaining all Federal, State, Local and other permits for construction of the shoring project.

i. The Engineer-of-Record shall be registered in the state of the project location. The Engineer-of-

Record may be Applicant’s in-house staff or a consultant retained by the Applicant. The Contractor shall not employ the Engineer-of-Record as the Contractor's Engineer-of-Record or as a specialty engineer, with the exception of design build projects.

n. The Applicant and/or the Engineer-of-Record have the ultimate responsibility and liability for the

Construction Documents and liability for damages to Railroad property during and after construction of the shoring.

o. The Contractor is responsible to comply with the construction documents prepared by the Applicant. The

Contractor shall comply with Railroad requirements stated in the C & M Agreement prior to the commencement of any construction. The Contractor shall develop work plans that ensure the track(s) remain open to train traffic per Railroad requirements as stated in the C & M Agreement and meet the requirements of the Railroad Right-of-Entry Agreement (if applicable).

p. The Applicant and Contractor is responsible for the security and safety of all people including the general public and trespassers, and the protection of Railroad infrastructure within the limits of the proposed shoring project. Any damage to Railroad property such as track, signal equipment or structure could result in a train derailment. All damages must be reported immediately to the Railroad Local Representative and to the local Railroad Track Maintenance Representative.

q. The Applicant and Contractor are required to meet all safety standards as defined by the Railroad, Federal

Railroad Administration (FRA), Division of Occupational Safety and Health Administration (OSHA), Local, State and Federal Governments and the State Railroad Regulatory Body.

TRACK, GROUND & SHORING MONITORING:

The Contractor must monitor the track, ground and shoring for movement to ensure proper performance of the shoring system and the safe operation of trains. Record top of rail elevations and track alignment for the duration of the project. After the project is complete additional track and ground monitoring may be required as deemed necessary by the Railroad.

a. Track & Ground Monitoring requirements: In addition to Table 2:

• For UPRR, see the Union Pacific Railroad Guidelines for Track & Ground Monitoring.

• For BNSF, subject to direction of the BNSF project engineer for the project

ii. Deflection Limits (Table 2), Section 3.8k, for both track and shoring deflection limits.

• Displacements exceeding the limits defined in Table 2 must be immediately reported to the

Railroad. All work on the project must stop and the Railroad may take any action necessary to ensure safe passage of trains. The Contractor must immediately submit a corrective action plan to the Railroad for review and approval. The Railroad must review and approve the proposed repair procedure. The repair must be inspected by the Railroad before any work on the project can proceed.

b. Any damage to Railroad property such as track, signal equipment or structure could result in a train derailment. All damage must be reported immediately to the Railroad representative in charge of the project and to the Railroad Track Maintenance Representative.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 5

RAILROAD RIGHT-OF-WAY

a. The Railroad Right-of-Way accommodates existing tracks, drainage systems, multiple utilities, access roads, Railroad support facilities and space for future track(s).

b. The proposed project shall not limit existing or future Railroad operating capacity and utility accommodations within the Railroad Right-of-Way.

c. Limits of Railroad Right-of-Way are to be located by the Applicant and identified on the plans.

CONSTRUCTION AND MAINTENANCE AGREEMENT

a. Prior to construction on Railroad Right-of-Way, Applicants must have an executed a C & M Agreement with the Railroad.

b. The C & M agreement shall, at a minimum, include a funding source, cost estimate, insurance and indemnification requirements, method of payment, responsibility for design, construction, ownership, maintenance and future replacement.

c. The Applicant shall own, maintain and replace the proposed project at no cost to the Railroad and with no interruption to Railroad operations during construction, maintenance and future replacement of the structure.

d. The Railroad shall, at its own expense, be responsible for ownership and maintenance of ballast and track components only.

e. The Applicant shall provide, at no cost to the Railroad, traffic control and/or detours to allow occupation of the roadway by the Railroad or its contractor(s) to perform periodic inspections as required.

f. The Applicant is responsible for performing the work in accordance with the terms specified in the C & M

Agreement.

RAILROAD REVIEW PROCESS

a. How to Communicate with the Railroad

i. All design and construction submittals shall be sent to the Railroad Representative who will pass them along for Railroad review.

b. Railroad Compensation Agreement:

i. Prior to any review, the Railroad Local Representative shall receive written notice from the Applicant agreeing to pay all costs associated with the Railroad’s (or its consultant’s) review of the design plans, construction documents and construction monitoring phase. This is often referred to as the

Preliminary Engineering Agreement (PE Agreement).

ii. The estimated costs of such PE Agreement shall not be the upper limit of the costs but will provide a guideline for budgeting purposes. Regardless, all actual costs incurred by the Railroad (or its consultants) during the review of design plans, construction documents, and construction monitoring submittals shall be fully recoverable from the Applicant.

c. Railroad Review Duration

i. Review of design submittals and resubmittals by the Railroad (or its consultants) will require a minimum of 4 weeks each individual submission to the Railroad.

ii. To expedite the review process of the temporary shoring plans, drawings submitted to the Railroad shall be in accordance with these Guidelines. Otherwise, longer review times shall be expected.

iii. To avoid impacting the construction schedule, the Contractor should schedule submittals at least 4 to

6 months in advance.

iv. Partial, incomplete or inadequate designs will be rejected, thus delaying the approval.

v. Revised submittals will follow the same procedure as the initial submittal until all issues are resolved.

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 6

d. Applicant and Engineer of Record Review

i. Before providing submittals for the Railroad to review, the applicant and or Engineer of Record must first review and approve the submittal for compliance with the project specifications, AREMA Manual, these Guidelines and structural capacity. Exceptions or proposed alternatives, if any, must be clearly communicated and identified for all submittals involved.

ii. Drawings and calculations must be signed and stamped by a licensed professional engineer familiar with railway loadings and is licensed in the state where the shoring system is intended for use.

e. Construction May Commence Only When:

i. The Contractor must not begin construction of any component of the shoring system affecting the

Railroad Right-of-Way until written Railroad approval has been received.

APPROVAL EXPIRATION

a. Written approval of Final Plans will be valid for two years from the date of approval by the Railroad unless otherwise provided in the C&M Agreement. If construction of the approved structure has not begun within this period, the Railroad shall have the right to perform a design review, at the cost of the Applicant, to confirm compliance with the Railroad’s then-current Guidelines before a Railroad Right-of–Entry

Agreement is issued to begin construction.

3. DESIGN

GENERAL DESIGN REQUIREMENTS

a. Shoring Zones (see Figure 1 below):

i. All dimensions are measured perpendicular to the centerline of track.

ii. For ALL excavations within Zone A, shoring plans shall be accompanied by design calculations.

iii. All shoring within the limits of Zone A must be placed prior to the start of excavation.

FIGURE 1

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 7

b. Excavation Limits: No excavation shall be permitted closer than 15’-0” measured at a right angle from the centerline of track to the trackside of shoring system.

c. Evaluate slope and stability conditions to ensure the Railroad embankment will not be adversely affected.

Local and global stability conditions must also be evaluated.

d. Lateral clearances must provide sufficient space for construction of the required Railroad ditches parallel to the standard Railroad roadbed section. The size of ditches will vary depending upon the flow and terrain and should be designed accordingly.

e. Protect Open Excavations:

i. Any excavation, holes or trenches on the Railroad property shall be covered, guarded and/or protected. Handrails, fence, or other barrier methods must meet OSHA and FRA requirements.

Temporary lighting may also be required by the Railroad to identify tripping hazards to train crewmen and other Railroad personnel.

f. The most stringent project specifications shall be used of the Public Utilities Commission Orders, Department of Industrial Safety, OSHA, FRA, AREMA, BNSF, UPRR or other governmental agencies.

g. Secondhand material is not acceptable unless the Engineer of Record submits a full inspection report which verifies the material properties and condition of the secondhand material. The report must be signed and sealed by the Engineer of Record.

h. Shoring Removal:

i. All components of the shoring system are to be removed when the shoring is no longer needed to the extent that there is no impact to Railroad operations. All voids must be filled and compacted properly, and drainage facilities restored. See compaction requirements in Section 3.5c.

ii. If the shoring cannot be completely removed, it shall be removed at least 3.0 feet below the final finished grade or at least 3.0 feet below the base of rail, whichever is lower, unless otherwise specified by the Railroad and only if approved by the Railroad.

iii. No traffic during unsupported excavations resulting from shoring removal.

i. Soldier piles may be installed in predrilled holes if the requirements of AREMA, Vol. 2, Ch. 8, Article

28.5.4.3 and the following are met:

i. Slurry and drilling fluid type materials are not acceptable as backfill for soldier piles in drilled holes.

ii. Concrete and flowable backfill may be used but might prevent removal of the embedded piles. If width of the drilled hole will be relied on for passive resistance, the concrete backfill shall have a minimum compressive strength of 3,000 psi, and a minimum coverage of at least 3.0 inches between the edge of the pile and drilled hole.

iii. Compacted pea gravel material is allowed as backfill if the groundwater level is below the bottom of the drilled hole, the diameter of the hole is at least 12 inches greater than the diagonal width of the pile, and the pea gravel is placed in successive lifts of 8 inches or less in thickness and either consolidated by vibrating the pile or being dry rodded between each lift. The design passive resistance shall be based on the lessor of that derived from either the surrounding subsurface soils or the pea gravel. The pea gravel shall be assumed to have a friction angle no greater than 34 degrees.

iv. Temporary or permanent casing is used to support the sides of the drilled hole for holes drilled within

25 feet from centerline of track, or 2 times the hole diameter plus 15 feet from centerline of track, whichever is greater. The thickness and strength of the steel casing shall be sufficient to support the loads described in Section 3.7, and shall be specified on the plans.

j. Tieback & Soil Nail Anchor Rods

i. Soil Nails are defined as drilled-in ground anchors that require ground and wall movement to occur before fully utilized, and Tiebacks are defined as tie rods and drilled-in ground anchors that are prestressed after installation.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 8

ii. Tiebacks & Soil Nails are not approved to permanently retain Railroad embankment supporting tracks.

iii. Tiebacks & Soil Nails installed below active tracks shall be cased during anchor installation.

iv. Tiebacks & Soil Nails shall be installed a minimum of 6 feet below base of rail, unless comprised of fiberglass or fully removed after the shoring is no longer needed. Additionally, the upper surface of the grouted tieback or soil nail shall be no less than 3.5 feet below base of rail.

v. Tiebacks & Soil Nails shall be designed for gravity placement of grout unless pressure grouting can be proven to not cause an unacceptable risk of track heave.

vi. For shoring that will extend above existing grade, which will result in the shoring being backfilled with compacted fill, settlement of the backfill, and associated impacts to shoring and adjacent structures, shall be evaluated. If tieback tie rods will be installed within the compacted backfill, the tie rods shall be placed in the bottom of pipe sleeves that have sufficient diameter to prevent vertical loading on the tie rods from backfill settlement. The pipe sleeves shall also have sufficient strength to support overburden backfill and surcharge loads.

vii. The contractor is responsible for providing an approved test method to verify the capacity of anchored or tieback systems. The manufacturers recommendations for testing must be satisfied. Systems which support the Railroad embankment will be considered high risk in determining the percentage of elements to be proof tested.

viii. Cement-grouted anchors tiebacks shall be installed, tested and stressed in accordance with the project specifications, AREMA requirements, FHWA-IF-99-015, Geotechnical Engineering Circular 4, Ground Anchors and Anchored Systems.

k. The proximity of existing structures shall be evaluated when determining shoring installation methods.

Installation of shoring by vibratory or impact hammers has the potential to cause dynamically induced subsidence of existing structures and track. The Railroad may dictate shoring installation methods as required on a case by case basis.

INFORMATION REQUIRED

a. Plans and calculations shall be submitted, signed and stamped by a Licensed Professional Engineer familiar with Railroad loadings and who is licensed in the state where the shoring system is intended for use. See Section 3.9 for requirements on plan submittals. In addition to plans and calculations, the following information is also required.

b. Field Survey

i. The field survey shall be referenced to the centerline of track(s) and top of rail elevations. Existing grades and alignment of tracks and roads shall be surveyed. The location of existing utilities shall also be determined.

c. Drainage

i. The drainage pattern of the site before and after construction should be analyzed and adequate drainage provisions should be incorporated into the plans and specifications. Consideration should be given to groundwater seepage as well as surface drainage.

ii. Drainage provisions for backfill should be compatible with the assumed water conditions in design.

d. Geotechnical Report – See Section 3.5, Subsurface Characterization.

e. Assumed Loading – See Section 3.7, Applied Loads and Calculations.

f. Structural Design Calculations – See Section 3.8, Structural Design Calculations.

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 9

DESIGN PROCEDURE

a. Shoring design should generally adhere to the following procedure:

Step 1) Determine proposed excavation location and depth.

Step 2) Establish subsurface and surface conditions at proposed shoring location. See Section 3.5 for requirements.

Step 3) Select shoring type (see Section 3.6)

Step 4) Determine Applied Loads

• Lateral Driving Pressures on back side of shoring, which would consist of the following:

o Earth pressure (Active, At-Rest, Apparent) (see Sections 3.7c.i, 3.7c.ii, and 3.7c.iii) o Surcharge pressures (see Section 3.7c.iv) o Hydrostatic pressure (see Section 3.7c.v)

• Lateral Resisting Pressures on the front side of shoring, which would consist of the following:

o Passive earth pressure (see Section 3.7d.i).

o Passive earth pressure reductions (e.g., seepage uplift) (see Section 3.7d.ii) o Resisting loads from braces and tiebacks

Step 5) Perform Structural Design Calculations

• Perform stability analysis to establish the minimum embedment depth of shoring and anchor/brace loads (see Section 3.8j).

o For complex shoring designs, perform global and basal heave stability analyses (see

Section 3.8j).

• Verify deflection is within that allowable (see Section 3.8k).

• Verify strength of structural elements are not exceeded (see Section 3.8i)

(Step 1) EXCAVATION LOCATION

a. See Figure 1, Section 3.1b for excavation limits.

b. Shoring systems should be located as far from the Railroad track and structures as possible.

(Step 2) SUBSURFACE CHARACTERIZATION

a. Subsurface exploration.

i. Sufficient borings shall be made along the length of the structure to determine, with a reasonable degree of certainty, the subsurface conditions. Irregularities found during the initial soil boring program may dictate that additional borings be performed.

ii. In general, borings should be performed within 50 feet of the planned location of shoring, or closer as necessary. If the planned shoring is longer than 250 feet in length, additional borings shall be performed along the length of the shoring on an average spacing of 250 feet.

iii. Borings shall be performed to a depth sufficient to fully characterize the soils adjacent to and below the proposed shoring.

iv. Unless otherwise stated in these guidelines, subsurface investigation shall also be made in accordance with the provisions of AREMA, Vol. 2, Ch. 8, Part 22, Geotechnical Subsurface

Investigation.

b. Type of backfill and backfill properties.

i. Backfill is defined as material behind the wall, whether undisturbed ground or compacted fill, that contributes to the pressure against the wall.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 10

ii. The compacted fill may be classified with reference to the soil types described in AREMA Vol. 2, Ch.

8, Articles 5.2.5 and 5.3.2. However, the unit weight used in design shall be representative of the actual unit weight of the material as measured by laboratory testing.

c. Backfill placement and compaction.

i. The compacted fill shall meet the latest version requirements of Section 31 23 26 of the UPRR

General Conditions and Specifications (UPRR) or BNSF Standard Construction Specifications

(BNSF).

ii. No dumping of backfill material shall be permitted in such a way that the successive layers slope downward toward the wall. The layers shall be horizontal or shall slope downward away from the wall.

iii. If the wall is not free to rotate (i.e., is anchored or braced) and achieve an active condition during compaction of the backfill, the induced earth pressure due to compaction shall be evaluated. The assumed earth pressure shall be no less than the at-rest earth pressure (see Section 3.7c.ii).

d. Stress states and corresponding soil strength properties.

i. Saturated cohesive soils (clays and some silts) can reside in two different stress states while shoring is in service:

• Undrained / Total Stress: A short-term condition where the undrained shear strength (Su) of the soil should be used for analysis.

• Drained / Effective Stress: A long-term condition where drained effective friction angle (’) and effective cohesion (c’) of the soil should be used for analysis.

ii. It is impossible to accurately predict how long saturated cohesive soils will remain in an undrained / total stress state before pore pressures dissipate and the soil achieves a drained / effective stress state. For this reason, the Undrained Cohesive soil state shall only control for design when it results in a higher factor of safety for the shoring design than that estimated for the Drained Cohesive soil state. This will generally only be the case when the cohesive soils are relatively soft.

iii. It is noted that cohesive soils can also reside in an “unsaturated” state, where the soil can be characterized by an unsaturated shear strength. The unsaturated shear strength of a cohesive soil can vary drastically as it’s moisture content increases or decreases. Given the impossibility of predicting moisture content changes for soils exposed to weather and groundwater fluctuations, the unsaturated shear strength of the soil shall not be used for design.

iv. Saturated and unsaturated cohesionless soils (some silts, sands, and gravels) should be assumed to always reside in a drained / effective stress state.

e. A Geotechnical Report summarizing the existing and proposed subsurface conditions shall be provided by a Licensed Professional Engineer. The Geotechnical Report shall include:

i. Boring location plan showing the location of each boring in relation to tracks and the proposed shoring.

ii. Boring logs that indicate the elevation and depth of each layer of soil encountered, USCS classification of each layer of soil, an indication of whether the soil is fill or natural soil, the depth/elevation of groundwater, results of in-situ testing, index properties of the soil layers as determined by laboratory testing (e.g., moisture, density, sand content, plasticity, unconfined strength, etc.)

iii. Results of all laboratory testing. Laboratory testing shall include at a minimum: moisture content, density, unconfined compression tests on clay/rock, and direct shear or triaxial compression testing on soils to determine the effective cohesion and internal angle of friction.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 11

iv. Recommended soil properties for the design of shoring for each layer of soil as follows:

• Top/bottom elevation of soil layer

• Moist () and effective (’) unit weight

• Undrained shear strength (Su) of cohesive soils

• Effective cohesion (c’) and friction angle (’)

• Active and passive earth pressure coefficients

• Parameters for p-y curve generation, if necessary.

v. If required, allowable bearing capacity for spread footings.

vi. Compaction recommendations for backfill, optimum moisture content and maximum density of fill material, and design parameters for the compacted fill. See Sections 3.5b and 3.5c.

vii. Water table elevation to be assumed on both sides of the shoring system.

viii. Dewatering recommendations, as needed, and proposed flownets or zones of groundwater influence.

(Step 3) SHORING TYPES

a. Shoring/Trench Box is a prefabricated shoring system which is installed as the excavation progresses.

This system is allowed in special applications only, typically where Railroad live load surcharge is not present unless it can be shown that the over excavation outside the box will be filled and compacted before the presence of Railroad live load.

b. Anchored systems with tiebacks are discouraged, as the tiebacks will be an obstruction to future utility installations and may also damage existing utilities. If used, see Section 3.1.j for design requirements for tiebacks and soil nails.

c. Sheet Pile Wall (Anchored) is a structure designed to provide lateral support for a soil mass and derives stability from passive resistance of the soil in which the sheet pile is embedded and the tensile resistance of tiebacks.

d. Sheet Pile Wall (Cantilevered) is a structure designed to provide lateral support for a soil mass and derives stability from passive resistance of the soil in which the sheet pile is embedded. Cantilever sheet pile walls shall be used only in granular soils or stiff clays. The maximum height of wall above the excavation line shall be 10 feet in Zone A (see Figure 1) and 12 feet in Zone B.

e. Soldier Pile with Lagging Wall (Anchored) is a structure designed to provide lateral support for a soil mass and derives stability from passive resistance of the soil/rock in which the soldier beam is embedded and from the tensile resistance of tiebacks. Soldier beams include steel H-piles, wide flange sections or other fabricated sections that are driven or set in drilled holes. Lagging refers to the members spanning between soldier beams.

f. Soldier Pile with Lagging Wall (Cantilever) is a structure designed to provide lateral support for a soil mass and derives stability from passive resistance of the soil/rock in which the soldier beam is embedded. The maximum height of the wall above the excavation line shall be 8 feet for Zone A (see Figure 1) and 12 feet for Zone B.

g. Braced Excavation is a structure designed to provide lateral support for a soil mass and derives stability from passive resistance of the soil in which the vertical members are embedded and from the structural capacity of the bracing members. For purposes of these guidelines, the vertical members of the braced excavation system include steel sheet piling or soldier beams comprised of steel H-piles, wide flange sections, or other fabricated sections that are driven or installed in drilled holes. Wales are horizontal structural members designed to transfer lateral loads from the vertical members to struts or rakers. Struts and rakers are structural compression members that support the lateral loads from the wales and transfer the load to either another side of a shored excavation (struts) or to a reaction pile/thrust block (raker).

h. Cofferdam is an enclosed temporary structure used to keep water and soil out of an excavation for a permanent structure such as a bridge pier or abutment or similar structure. Cofferdams may be

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 12

constructed of timber, steel, concrete or a combination of these. These guidelines consider cofferdams primarily constructed with steel sheet piles.

(Step 4) APPLIED LOADS AND CALCULATIONS

a. For shoring design submittal, all design criteria, temporary and permanent loading must be clearly stated in the design calculations and on the contract and record plans.

b. Applied loading will consist of driving pressures/forces on the back of the shoring and resisting pressures/forces on the front of the shoring.

• Driving pressure will generally consist of:

o Active, At-Rest & Apparent pressures. (Sections 3.7c.i, 3.7c.ii, 3.7c.iii) o Surcharge (Section 3.7c.iv) o Hydrostatic pressures (Section 3.7c.v).

• Resisting pressure will generally consist of:

o Passive earth pressure (3.7d.i) and brace/tieback loading.

c. Driving Pressures/Loads:

i. Active Earth Pressure

• Use for cantilever walls and flexible walls with only one row of tiebacks/braces (i.e., flexible anchored bulkheads), if the minimum deflection criteria per AREMA Vol. 2, Ch. 8, Article

20.1.2.d is met. If the minimum deflection criteria for flexible anchored bulkheads is not met, use Apparent Earth Pressure for top-down shoring construction (Section 3.7c.iii), and At-Rest

Earth Pressure for walls that are backfilled (Section 3.7c.ii).

• The active earth pressure may be computed by the Rankine, Coulomb or Log-Spiral theories.

The active earth pressure may also be based on general soil type per AREMA Vol. 2, Ch. 8, Part 20, Table 8-20-3 as provided in the Appendix.

• For interface friction angles used for Coulomb and Log-Spiral theories, the interface friction angle shall not be greater than one-half of the effective friction angle of the soil, or that consistent with published values for specific types of soil in contact with either steel or concrete (e.g., NAVFAC DM7.02, Chapter 3, Table 1).

• The backslope of the retained soil shall be considered when calculating the active earth pressure.

• See Section 3.5b. Subsurface Characterization, for further requirements for computing earth pressure from compacted backfill.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 13

FIGURE 2

❖ NON-COHESIVE SOILS

Level Backslope (Rankine) 𝜎𝐴𝐻 = 𝐾𝐴 𝛾 𝑧 , 𝑤ℎ𝑒𝑟𝑒 𝐾𝐴 = 𝑡𝑎𝑛2 (45 − 𝜙′

Sloping Backslope (Rankine) 𝜎𝐴𝐻 = 𝐾𝐴 𝛾 𝑧 𝑐𝑜𝑠 𝛽 , 𝑤ℎ𝑒𝑟𝑒 𝐾𝐴 = cosβ ( 𝑐𝑜𝑠𝛽 − √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ 𝑐𝑜𝑠𝛽 + √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′

❖ COHESIVE SOILS & FRACTURED ROCK

Drained Cohesive & Fractured Rock - Level & Sloping Backslope (Rankine/Bell)

▪ Use these drained equations unless the undrained equations below result in greater earth pressures in the shoring design.

𝜎𝐴𝐻 = 𝐾𝐴 𝛾𝑧 − 2𝑐′√𝐾𝐴

𝐾𝐴 = 𝑡𝑎𝑛2 (45 −

𝜙′

) , 𝐹𝑜𝑟 𝐿𝑒𝑣𝑒𝑙 𝐵𝑎𝑐𝑘𝑠𝑙𝑜𝑝𝑒

𝐾𝐴 = cosβ ( 𝑐𝑜𝑠𝛽 − √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ 𝑐𝑜𝑠𝛽 + √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ ) , 𝐹𝑜𝑟 𝑆𝑙𝑜𝑝𝑖𝑛𝑔 𝐵𝑎𝑐𝑘𝑠𝑙𝑜𝑝𝑒

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 14

▪ Effective Cohesion Note: Effective cohesion shall be assumed to be zero, unless local experience by a Licensed Geotechnical Engineer indicates the fully softened strength of the clay will have an effective cohesion greater than zero.

▪ Fractured Rock Note: The active earth pressure for fractured rock and intermediate geomaterials (e.g., weak shales, sandstone, etc.) shall be based on either the rock mass effective cohesion and friction angle, or mass shear strength. The mass strength parameters shall be determine using a methodology that accounts for rock type, intact strength, spacing and conditions of joints, rock quality designation (RQD), geological strength index (GSI), and/or rock mass rating (RMR).

Undrained Cohesive – Level Ground (Rankine/Bell)

▪ Only use undrained when it results in a higher earth pressure in the shoring design.

Otherwise use the Drained equations above.

▪ Assumes =0 and c’=Su 𝜎𝐴𝐻 = 𝛾𝑧 − 2𝑆𝑢 𝒐𝒓 𝜎𝐴𝐻 = 𝐾𝐴 𝛾 𝑧 , 𝑤ℎ𝑒𝑟𝑒 𝐾𝐴 = 1 −

2𝑆𝑢 𝛾𝑧

Very Soft to Medium Clays/Silts

▪ Where the Stability Number Ns = *H/Sub is greater than 4, active earth pressure shall be estimated as the greater of that determined using the equations above for drained

(effective) and undrained (total stress) conditions, or the equations directly below. The factor of safety against basal heave shall also be analyzed per Section 3.8j.ii3.8. For

Ns > 6, the global stability of the shoring shall also be evaluated by a limit-equilibrium method of slices per Section 3.8j.ii.

o For 4 < Ns < 5.14, 𝐾𝐴 = 0.22 o For Ns > 5.14 (Henkel, 1971), 𝐾𝐴 = 1 − 4𝑆𝑢 𝛾𝐻 + 2√2 𝑑

𝐻 (1 −

5.14𝑆𝑢𝑏 𝛾𝐻 ) ≥ 0.22

Where:

Su = Undrained strength of retained soil (lbf/ft2)

Sub = Undrained strength of soil below excavation base (lbf/ft2)

= Total unit weight of retained soil (lbf/ft3)

H = Total excavation depth (ft) d = Depth of potential base failure surface below base of excavation (ft)

(The lessor of either the thickness of soft to medium stiff clay below the bottom of excavation, or the width of the excavation divided by the square root of 2. See Figure 3 below.)

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 15

FIGURE 3

ii. At-Rest Earth Pressure.

• Used for rigid walls (e.g., reinforced concrete walls) that deflect less than that indicated in

Table 1.

Table 1 - When to Use At-Rest Earth Pressure

Type of Backfill Wall Deflection / Wall Height

Dense sand 0.001

Medium dense sand 0.002

Loose sand 0.004

Compacted Silt 0.002

Compacted lean clay 0.010

Compacted fat clay 0.010

(Clough & Duncan, 1991)

• At-Rest earth pressure shall also be used for walls that are restrained above the dredge line by braces/tiebacks and are backfilled with compacted fill. See also Section 3.8j.ii.

• At-Rest earth pressure shall be calculated as follows:

Level Ground 𝜎0𝐻 = 𝐾0 𝛾 𝑧 , 𝑤ℎ𝑒𝑟𝑒 𝐾0 = (1 − 𝑠𝑖𝑛𝜙′)𝑂𝐶𝑅(𝑠𝑖𝑛𝜙′)

Sloping Backslope 𝜎0𝐻 = 𝐾0 𝛾 𝑧 (1 + s𝑖𝑛 𝛽)

Where:

0H – Horizontal At-Rest Earth Pressure (lbf/ft2)

K0 – At-Rest Earth Pressure Coefficient

’ – Effective Friction Angle (deg)

OCR – Over-Consolidation Ratio

– Backslope Angle (deg)

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 16

iii. Apparent Earth Pressure

• Use for braced excavations with single or multiple levels of braces/tiebacks.

• Use equations determined per AREMA Vol. 2, Ch. 8, Article 28.5.4.1 or FHWA-IF-99-015, Sections 5.2.4 (sands), 5.2.5 (stiff to hard clays) and 5.2.6 (soft to medium clays).

• For braced excavations that bottom out in very soft to medium stiff clays/silts, where the

Stability Number Ns = *H/Sub is greater than 4, the requirements of Section 3.7c.i for very soft to medium clays shall also apply if they control for design.

iv. Surcharge Loads

• Loads include but are not limited to: Railroad vertical and centrifugal loading, railroad service vehicles (HS-20 truck), roadway loading, fills placed above the top of shoring, construction equipment, crane pads, future grading and paving, structures, material storage piles, and snow.

• Dead load assumptions to be used for design:

o Spoil pile: must be included assuming a minimum height of two feet of soil adjacent to the excavation.

o Track: use 200 lbs/linear-ft for rails, inside guardrails and fasteners.

o Roadbed: ballast, including track ties, use 120 lbs per cubic foot.

• For specific applications of the Cooper E80 live load, refer to in Appendix 5.1, which illustrates

Live Load Pressure Due to Cooper E80.

• Additional analysis for centrifugal force calculations as described in AREMA Vol. 2, Ch. 15, Article 1.3.6. Centrifugal Loads are required where shoring is located along the outer side of curved track and track curvature exceeds three degrees.

• Lateral pressure from to infinite and uniform surcharge load.

o The surcharge can effectively be treated as another soil layer, whereby the vertical surcharge pressure is multiplied by the active or at-rest earth pressure coefficient as shown below:

𝜎𝑈𝐴 = 𝐾𝐴𝑞 𝑜𝑟 𝜎𝑈0 = 𝐾0𝑞

Where:

UA – Uniform lateral surcharge pressure for active condition (lbf/ft2)

U0 – Uniform lateral surcharge pressure for at-rest condition (lbf/ft2)

KA - Active earth pressure coefficient

K0 – At-rest earth pressure coefficient q - Uniform surcharge load (lbf/ft2)

• Lateral pressure from to point, line, uniform strip, and rectangular-area surcharge loads.

o Equations shall be based on Boussinesq theory (i.e., elastic theory) and a rigid wall condition.

o For point loads, see AREMA, Vol. 2 , Ch. 8, Article 20.3.2.4.

o For line loads, see AREMA, Vol. 2 , Ch. 8, Article 20.3.2.3.

o For rectangular loads, see NAVFAC DM7.02, Figure 11.

o For uniform strip loads, see Case I (Cooper E80 loading parallel to walls) in Appendix

5.1, or AREMA, Vol. 2 , Ch. 8, Article 20.3.2.2.

• Trial Wedge method per AREMA, Vol. 2 , Ch. 8, Article C5.3.2.II may also be used.

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UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 17

v. Hydrostatic Pressure Due to Unbalanced Groundwater Levels.

• Hydrostatic pressure shall be assumed on secant/tangent pile and sheet pile shoring if the base of the excavation extends below the water table and no drainage system is installed behind the shoring.

• Weep holes are not considered an effective drainage system, unless the soil behind the shoring above the dredge line is uniformly free-draining granular material.

d. Resisting Pressures/Loads:

i. Passive earth pressure

• The passive earth pressure, Pp, below the excavation line may be computed by Rankine or

Log-Spiral theories, but not the Coulomb theory.

• For Log-Spiral theory, the interface friction angle shall not be greater than one-half of the effective friction angle of the soil, or that consistent with published values for specific types of soil in contact with either steel or concrete.

• The passive earth pressure for cohesionless soils (sands, gravels and some silts), uncontrolled fill, and mixed layers of cohesive and cohesionless soil shall be calculated based on the effective friction angle of the soil.

• The passive earth pressure for cohesive (clay and some silts) soils and controlled backfill shall be calculated for the effective stress condition (see Section 3.5d.i for definition), unless the resulting earth pressure for the total stress condition (i.e., Su) is less.

• For conditions where the slope in front of the shoring slopes down and away from the wall, the slope in front of the wall shall be considered when calculating passive pressure. If the ground in front of the shoring slopes upwards away from the wall, the ground level shall be assumed to be level for analysis.

• For reference, Rankine equations are provided below:

KP – Passive Earth Pressure Coefficient

PH – Horizontal Passive Earth Pressure (lbf/ft2)

’ – Effective Friction Angle (deg) c’ – Effective cohesion (lbf/ft2)

Su – Undrained Shear Strength (lbf/ft2)

– Moist Unit Weight of Soil (lbf/ft3) z – Depth Below Ground Surface (ft)

– Front Slope Angle (deg)

NON-COHESIVE SOILS

Level Frontslope (Rankine) 𝜎𝑃𝐻 = 𝐾𝑃 𝛾 𝑧 , 𝑤ℎ𝑒𝑟𝑒 𝐾𝑃 = 𝑡𝑎𝑛2 (45 + 𝜙′

Sloping Frontslope (Rankine)

▪ Use only if ground is sloping down and away from shoring (i.e., is negative) 𝜎𝑃𝐻 = 𝐾𝑃 𝛾 𝑧 cos 𝛽 , 𝑤ℎ𝑒𝑟𝑒 𝐾𝑃 = cosβ ( 𝑐𝑜𝑠𝛽 + √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ 𝑐𝑜𝑠𝛽 − √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′

UPRR & BNSF GUIDELINES FOR TEMPORARY SHORING, 12/7/2021 18

COHESIVE SOILS & FRACTURED ROCK

Drained Cohesive & Fractured Rock - Level & Sloping Backslope (Bell’s) 𝜎𝑃𝐻 = 𝐾𝑃 𝛾𝑧 + 2𝑐′√𝐾𝑃

𝐾𝑃 = 𝑡𝑎𝑛2 (45 +

𝜙′

) , 𝐹𝑜𝑟 𝐿𝑒𝑣𝑒𝑙 𝐹𝑟𝑜𝑛𝑡𝑠𝑙𝑜𝑝𝑒

𝐾𝑃 = cosβ ( 𝑐𝑜𝑠𝛽 + √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ 𝑐𝑜𝑠𝛽 − √𝑐𝑜𝑠2𝛽 − 𝑐𝑜𝑠2𝜙′ ) , 𝐹𝑜𝑟 𝑆𝑙𝑜𝑝𝑖𝑛𝑔 𝐹𝑟𝑜𝑛𝑡𝑠𝑙𝑜𝑝𝑒

▪ Effective cohesion shall be assumed to be zero unless local experience by a Licensed

Geotechnical Engineer indicates the fully softened strength of the clay will have an effective cohesion greater than zero.

▪ The passive resistance for fractured rock and intermediate geomaterials (e.g., weak shales, sandstone, etc.) shall be based on either the rock mass effective cohesion and friction angle, or mass shear strength. The mass strength parameters shall be determine using a methodology that accounts for rock type, intact strength, spacing and conditions of joints, rock quality designation (RQD), geological strength index

(GSI), and/or rock mass rating (RMR).

Undrained Cohesive – Level Ground (Rankine/Bell)

▪ Only use undrained when it results in a lower earth pressure in the shoring design.

Otherwise use Drained equations above.

▪ Assumes =0 and c’=Su 𝜎𝑃𝐻 = 𝛾𝑧 + 2𝑆𝑢 𝒐𝒓 𝜎𝑃𝐻 = 𝐾𝑃 𝛾 𝑧 𝑤ℎ𝑒𝑟𝑒 𝐾𝑃 = 1 +

2𝑆𝑢 𝛾𝑧

• For soldier pile walls, the upper 1.5 pile/shaft diameters of passive resistance in soil below the excavation line shall be ignored per AREMA, Vol. 2, Ch. 8, Article 28.5.3.2.a.

• Allowable arching factors for soldier pile walls shall comply with AREMA, Vol. 2, Ch. 8, Article

28.5.3.2.a.

• As noted in Section 3.1i.ii above, the width of the drilled hole for a soldier pile shall not be assumed to provide passive resistance unless the concrete backfill has a minimum compressive strength of 3,000 psi, and a minimum coverage of at least 3.0 inches between the edge…