existing bridge scour scope 12-29-04(2)

EXHIBIT "A"

SCOPE OF SERVICES

FOR

DISTRICT-WIDE BRIDGE SCOUR EVALUATION

FINANCIAL PROJECT NO. xxxxxx x xx xx

Revised: 7/18/037/15/037/11/031/16/04


INDEX

Page No.

I. DESCRIPTION……………………………………………………….………………..A-1

II. OBJECTIVE……………………………………………………………………………A-1

III. PROVISIONS FOR WORK……………………………………………………………A-1

IV. SERVICES……………………………………………………………………………..A-2

A. PHASE I - DATA COLLECTION AND QUALITATIVE ANALYSIS…………..A-3

B. PHASE II - HYDROLOGIC & HYDRAULIC ASSESSMENT…………………..A-6

C. PHASE III - GEOTECHNICAL & STRUCTURAL SCOUR ASSESSMENT……A-9

D. PHASE IV - RECOMMENED ACTION…………………………………………A-10

V. QUALITY CONTROL PROGRAM………………………………………………….A-10

VI. PERSONNEL REQUIREMENTS……………………………………………………A-12

VII. DEPARTMENT RESPONSIBILITIES……………………………………………….A-13

VIII. BEGINNING AND LENGTH OF SERVICE………………………………………...A-13

February 17, 2004A-i

EXHIBIT “A”

FINANCIAL PROJECT NO.: xxxxxx x xx xx

SCOPE OF SERVICES


I. DESCRIPTION

The specific purpose of this scope is to evaluate various bridges over tidal and non-tidal waterways with scourable beds to determine the risk of failure from scour.

II. OBJECTIVE

The Florida Department of Transportation, hereinafter called the Department, desires consultant services for bridge scour evaluation on bridges within District X.

III. PROVISIONS FOR WORK

A. The Department recognizes the necessity of maintaining qualified expertise in the dynamic field of Bridge Scour Evaluation. A multi-disciplined Team of Engineers is required to ensure proper evaluation. Experts in Bridge Hydraulics/Hydrology, Coastal Engineering, Structures, and Geotechnology are required to come to a consensus on potential bridge scour associated problems and possible corrective actions. The key individuals within the team having direct oversight of this work must demonstrate by formal education and or experience the ability to meet the qualifications described below. An individual may qualify in more than one discipline. Should any key individual terminate their employment relationship with the contracted firm, the Department must review and approve the replacement before continuation of any work requiring that expertise. Failure to maintain the required expertise makes the contract null and void at the option of the Department. Engineering analyses and calculations must be signed and sealed by the appropriate overseeing professional engineer.

B. The Consultant is required to perform a scour evaluation on various bridges in District X in accordance with this scope of services. The evaluation will be performed in four (4) Phases: (1) Data Collection and Qualitative Analysis, (2) Hydrologic and Hydraulic Assessment, (3) Geotechnical and Structural Scour Assessment, and (4) Recommend Plan of Action. Should the Plan of Action include the construction of scour countermeasures, the Consultant may be

A-1 February 17, 2004

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retained to provide construction support services such as shop drawing reviews and providing recommendations to resolve field problems. Services are governed by the following provisions:

1. A review shall be made at the completion of each phase to coordinate what course of action is needed and what should be included in the next phase. The Consultant shall not proceed with the next phase until authorization has been issued.

2. No work may be commenced until a written Task Authorization has been issued (see Article VIII, Beginning and Length of Services, of this Exhibit "A").

3. The Consultant shall research and conduct pile tests when requested by the Department to obtain the length of the imbedded piles if pile driving records are not available. Methods and procedures of the proposed pile testing must be approved by the Department and FHWA prior to any actual bridge site work.

4. The Consultant shall review available survey data to determine if there is a need for an additional survey. If required, the Department may authorize the additional survey to be secured by the Consultant.

5. The Consultant shall coordinate and attend technical review meetings with the Department personnel during the course of this study.

6. The Consultant is required to submit to the Department a scour evaluation report for each structure evaluated. This report shall contain all office and field data and all information relevant to the evaluation. This report shall be recorded on 8 1/2" x 11" sheets, fully titled, numbered, dated, indexed, and signed and sealed by the engineer of record according to Florida Statutes. Computer output forms and other oversized sheets shall be folded to 8 1/2" x 11" size. The data shall be bound in a hard back folder for submittal to the Department. Also, any computer files produced for this report shall become the property of the Department. Scour related structural stability evaluations of bridges with unknown foundations will be performed by task authorization only when prior FHWA approval has been obtained.

IV. SERVICES

This scope provides the information to be developed, and the methods and procedures to be followed in performing scour evaluations for existing waterway bridges in District X.

February 17, 2004A-2

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This scope document is not all-inclusive; the consultant engineer must use good judgment in its application to ensure that the evaluation is complete and appropriate for the site. Ingenuity in applying concepts and procedures is encouraged. However, approval from the Department's Reviewing Engineer must be obtained to vary from the general methodology and specific requirements presented in these guidelines. The FHWA Technical Advisory 5140.23 is referenced for policy guidelines in scour evaluation. The FHWA HEC-18 is referenced for detailed scour analysis process for riverine situations. The FHWA HEC-20 is also referenced for stream stability analysis. HEC-18 methodology should NOT be applied to analyze tidal hydraulics.

The intent of this scope document is to describe a phase process for bridge scour evaluation, with each phase being the completion of a logical step in the site evaluation. The findings of each step will provide guidance to the requirements and direction of evaluation for the next phase. A documentation and executive summary report for each completed phase will be provided to the Department’s Reviewing Engineer for approval before proceeding. This report will include plans of action for the next phase. It is possible that a conclusion could be reached at any phase in the process eliminating the need to proceed further.

The following is a summary description of the steps to be performed in each phase. Each site has its particular characteristics and levels of risk. The evaluation detail must be commensurate to these site specific factors. A form titled "Scour Evaluation Report" (provided by the Department) shall be used as summary documentation of the completed findings and recommendations unless a different format in writing is approved by the Department’s Reviewing Engineer. The report is to be appropriately completed for each phase.

Stream stability and scour evaluation for bridges shall be developed using a multi-disciplinary approach involving the hydraulics engineer, coastal engineer, geotechnical engineer, and the structures engineer. Each phase will involve the expertise of the appropriate technical specialists. It is the Consultant's responsibility to ensure the appropriate expertise and a coordinated approach is used in each phase.

Additional services may be provided by the Consultant based on need and negotiations with the Department. These services may include:

1. Soil survey,

2. Hydrographic survey,

3. Dive services

4. Pile Testing.


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A. Phase I: DATA COLLECTION AND QUALITATIVE ANALYSIS

The site and data analysis for this phase is qualitative and of the simplest form. It involves preliminary conclusions and findings based on the application of simple geomorphic concepts and the engineers' evaluation of data and site conditions.

There may be some instances where sufficient information is found and conditions are such that a scour assessment and bridge stability recommendation can be made at this level. Note: These steps are similar to those found in FHWA HEC-20.

1. Step 1 Perform an office data search and collection of information pertinent to the structure. When available, this data shall include:

· Construction and as-built plans;

· Bridge inspection reports;

· Hydraulic & hydrologic data;

· Foundation reports, test boring data, site geology, subsurface information;

· Other Agency Studies such as the Corps of Engineers (COE), Federal Emergency Management Agency (FEMA), Soil Conservation Service (SCS), United States Geological Survey (USGS), Water Management Districts (WMD), etc.;

· Mapping;

· Aerial photography;

· Gage data.

2. Step 2 Conduct a field investigation (not a formal survey) to supplement existing data found during the office investigation. Collect information such as:

· Sufficient topographic and elevation data to develop or supplement plan profile drawings of site;

· The current typical channel and flood plain cross-section beyond the area affected by the bridge crossing in


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accordance with bridge inspection standards;

· Probe where practicable to obtain or confirm structure foundation elevations;

· Observe and record channel and floodplain characteristics at as well as up and down stream of the crossing, in accordance with bridge inspection standards;

· Describe the observed geological conditions at the site including their influence on stream stability;

· Record any indications of scour in the area of the bridge;

· Describe bed and bank materials according to the most recent version of FHWA HEC-20. Sampling plans shall be submitted for approval by the Department’s Reviewing Engineer;

· Plot hydrographic survey (bridge channel cross-section) as required;

· Investigate and note any up or downstream activities, such as sand and gravel mining, reservoirs, or channel improvements, that would influence short or long term channel stability;

· Note any major changes or anticipated changes in the watershed over the life of the structure;

· Obtain information on flood history of the site (including local resident interviews where practical);

· Drift conditions and potential;

· Observe other general geomorphic features of the stream reach;

· Note any levees, dikes, or other stream controls;

· Note stream confluences;

· Record site and special stream factors with photographs.


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3. Step 3 Prepare and submit a qualitative summary report of this phase to the Reviewing Engineer. The report shall include:

· Drawings and photos of the site;

· Summary of important site data;

· Definition of the stream geomorphic characteristics according to the most recent edition of FHWA HEC-20;

· Definition of overall stream stability (lateral, vertical, potential responses);

· Conclusions and recommendations;

· General outline of proposed direction and study procedures for next phase.

B. Phase II: HYDROLOGIC & HYDRAULIC ASSESSMENT FOR SCOUR ANALYSIS

This phase involves the basic engineering analysis and development of quantitative information for bridge scour assessment. Guidance in specific areas of evaluations and levels of detailing will be provided in the findings of Phase I. It is very probable that the Phase I findings will identify some steps that can be eliminated in Phase II as well as some that need to be expanded.

1. Step 1 Evaluate flood history of the site and develop runoff relations.

· Significant, historical rainfall and hurricane events effecting the site of interest will be documented, as well as any documented scour from these events.

· A hydrologic analysis will be made to determine runoff conditions at the site. The analysis shall follow Chapter 4 of the FDOT Drainage Manual.

2. Step 2 A hydraulic analysis will be made to determine basic hydraulic conditions at the site, such as velocity and flow distribution. In some cases this information may be available from previous studies or existing design calculations. A tabular summary of the findings of the hydraulic analysis is to be prepared including finding of Step 5. Hydraulic analysis and scour prediction shall follow Chapter 4 of the FDOT Drainage Manual.


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3. Step 3 A grain size analysis shall be made of the bed and bank materials if appropriate as directed by the Department (collected in Task I) and readily available. Particle size gradation curves will be developed. Information on depths of material and erodability characteristics should be described.

4. Step 4 An evaluation of channel stability should be made through analysis of incipient motion parameters.

· Potential for development of a naturally occurring armor layer should be assessed using incipient motion analysis.

· FHWA publications HEC-20 and "Highways and the River Environment" are referenced for detailed procedures in incipient motion and armoring analysis.

5. Step 5 Calculate scour depths for the foundation components at the bridge crossing at a minimum for the conditions described below. Where tip elevations of deep foundation elements are unknown, unless directed otherwise by the department, calculate scour depths assuming the foundation tips extend beyond/below the maximum scour elevation.

· Design Frequency for Scour Estimates: Scour estimates shall be developed for the following conditions:

- Worst case scour condition up through the 100 year frequency flood event (Design Scour Flood Event);

- Worst case scour condition up through the 500 year frequency flood event (Check Scour Flood Event).

- Scour Components: Scour estimates for the above events shall consist of the total scour resulting from the following:

- Natural channel aggradation and degradation anticipated during the life of the structure;

- Channel migration anticipated during the life of the structure;

- Contraction scour;


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- Local scour, including pier scour and abutment scour.

- Abutment scour estimates are not required when standard rubble riprap protection is provided and the design velocities near the abutment do not exceed 1.22 meters per second (4 feet per second).

- Procedures presented in the most recent version of FHWA HEC-18 shall be used in developing the scour depths, except that Sheppard’s pier scour equation should be used for pier scour prediction rather than the comparable procedures in HEC-18.and the Florida scour-resistant materials approach should be used for evaluating scour resistant soils.

6. Step 6 Prepare and submit a summary report of this phase to the Reviewing Engineer. Reports on tidal bridges shall be signed and sealed by the Coastal Engineer. This report shall include:

· Plot of bridge foundation elements and computed scour depths, where deep foundation tips are unknown, denote same on plot, and also that related scour depths are based on foundation tip elevations assumed below depth of scour;

· Proposal and detailing of additional information required for analytical assessment of structure scour stability (specifically geology and unknown foundation determination);

· Conclusions and recommendations.

· General outline of proposed direction and study procedures for next phase.

C. Phase III: GEOTECHNICAL & STRUCTURAL SCOUR ASSESSMENT

1. Step 1 Analyze potential scour depth and extent, including consideration of the foundation material's resistance to scour.

2. Step 2 Analyze capacity of each foundation unit for loads and structural stability under scour conditions defined in Phase II, Step 5.


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3. Step 3 Evaluate live load capacities in accordance with the Department’s current load rating guidelines. When appropriate, recommend reduced load rating and/or posting limits

4. Step 4 For bridges found to be scour critical, scour susceptible, and/or with unknown foundations, establish recommendations for alternative plan(s)s of action (POA).

5. Step 5 Prepare and present summary of this phase to the Department’s Reviewing Engineer. This report shall include:

· Capacity of each foundation unit as defined in Step 2 above;

· Conclusions and recommendations.

· General outline of proposed direction and procedures for next phase.

D. Phase IV: RECOMMENDED ACTION

1. Develop a conceptual POA practical for protecting the traveling public and structural elements considered at risk due to scour and/or with unknown foundations should be developed. The POA shall include a minimum of one alternate countermeasure and a basic analysis for presentation and consideration by the Department’s interdisciplinary work group for final recommendation to the Department’s Reviewing Engineer for action.

2. Prepare and present a summary of the conceptual POA to the Department’s Reviewing Engineer. This report shall include:

· POA for long and/or short term –application and the technical pros and cons for each alternate;

For countermeasures and/or POA relying partially or completely on site inspections to ensure against structural failure due to flood/scour events, the report shall define, explain, and when possible quantify events that will trigger interim inspections, road posting, road closing or other protective actions.

· General construction quantities and cost estimates for an alternate repair plan and a recommendation regarding the


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most cost effective option(s).

V. QUALITY CONTROL PROGRAM

A. The Quality Control Program shall include the following elements:

1. Quality Reviews: The Consultant shall conduct quality reviews to make certain their own organization is in compliance with the requirements cited in this scope of services. Quality reviews shall be conducted to evaluate the adequacy of materials, documentation, processes, procedures, training, guidance, and staffing included in the execution of this contract. Quality reviews shall also be developed and performed to assure compliance with specific quality control provisions contained in this contract.

2. Quality Control Plan: The Consultant shall include a quality control plan in the technical proposal furnished to the Department. The quality control plan shall detail the procedures, evaluation criteria, and instruction to his organization to assure conformance with the contract. No work shall be initiated until the Consultant's quality control plan is approved by the Department. Significant changes to the work requirements may require the Consultant to revise the quality control plan. It shall be the responsibility of the Consultant to maintain a plan current with the work requirements. The Plan shall include, but not be limited to, the following areas.

3. Organization - A description is required of the Consultant's quality control organization and its functional relationship to the part of the organization performing the work under the contract. The authority, autonomy, and responsibilities of the quality control organization shall be detailed as well as the names and qualifications of personnel in the quality control organization.

4. Quality Assurance - The Consultant's quality control methods used to monitor and assure compliance with the contract requirements for services and products shall be detailed.

5. Quality Records - The types of records which will be generated and

maintained by the Consultant during the execution of a quality control program shall be outlined.

6. Control of Subcontractors and Vendors - The methods used by the Consultant to control the quality of the subcontractors and vendors shall be detailed.


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7. Quality Control Certification - An officer of the Consultant firm will be required to sign and seal a certification that will accompany each submittal stating that the plans, reports, etc. have been prepared and checked in accordance with Department Specifications.

B. The Consultant shall maintain adequate records of the quality control actions performed (including subcontractors and vendors) in providing services and products under this contract. All records shall indicate the nature and number of observations made, the number and type of deficiencies found, and the corrective actions taken. Deficiencies identified through the consultant’s qc and/or qa processes shall be reported to the department and immediately corrected to the department’s satisfaction. Failure to make satisfactory and timely correction to deficiencies identified by the consultant or by the department shall result in withholding of payments, pending satisfactory corrections being made. These records shall be available to the Department upon request during the contract term. All records shall be kept at the primary job site. All records are subject to audit review.

C. The quality control program should have a second level (peer) review. This peer review can be conducted by several methods. The review could be accomplished internally by the Consultant's organization or, at his own option, the Consultant may contract the review with another Consulting firm which must comply with the provisions of Section III of the Scope Of Services.

VI. PERSONNEL REQUIREMENTS

A. BRIDGE HYDRAULICS/HYDROLOGY

The Consultant:

· Must employ a Registered Professional Civil Engineer in Florida with a specialty in Hydraulics/Hydrologic Engineering.

· Must employ a coastal engineer who must hold a M.S. or Ph.D. in Coastal Engineering or a related Engineering field and/or have extensive experience (as demonstrated by technical publications in technical journals with peer review) in coastal hydrodynamics and sediment transport processes.

· Must be familiar with hydrologic methods applied in the Department's Drainage Manual.

· Must be knowledgeable in the theory and application of the Federal


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Highway Administration (FHWA) WSPRO Hydraulics Model.

· Must be knowledgeable in application of the scour equations set forth in FHWA Hydraulic Engineering Circular (HEC) HEC-18 and HEC-20.

· Must be knowledgeable in the application of the Sheppard’s pier scour equations as set forth in Florida’s Bridge Scour Workshop manual and the Florida rock / clay scour analysis methodology.

B. BRIDGE STRUCTURES

The Consultant:

· Must employ a Registered Professional Civil Engineer in Florida with a specialty in Structural Engineering.

· Must be knowledgeable in bridge design and with Florida structural design requirements as stated in the Department's Structural Design Guidelines.

· Must be familiar with American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications For Highway Bridges.

· Must be familiar with the Department's Manual For Bridge and Other Structures Inspection and Reporting Procedures.

· Must be familiar with Department’s current load rating criteria and knowledgeable in performing structural load ratings in accordance with this criteria.

C. BRIDGE GEOTECHNOLOGY

The Consultant:

· Must be a Registered Professional Civil Engineer in Florida with a specialty in Geotechnical Engineering.

· Must be knowledgeable of the geotechnical requirements of the Department's Specification 455 (Deep Foundations).


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· Must be competent in current Department static and dynamic foundation analysis techniques.

· Must be familiar with the Department's Geotechnical Design Manual.

· Must be knowledgeable in the application of the Florida Rock / Clay scour analysis procedure.

VII. DEPARTMENT RESPONSIBILITIES

The Department will provide access to the following items, as appropriate and when available, for performance of the required services:

· Existing original bridge plans;

· Bridge inspection reports and underwater inspection reports;

· Structures during reviews;

· Pile driving records;

· Hydrographic surveys;

· Drainage files and past bridge hydraulics reports.

· Scour Evaluation Report Format

· Field Review checklist

VIII. BEGINNING AND LENGTH OF SERVICE

A. Services shall be commenced and completed in accordance with Task Authorizations issued by the District Professional Services Administrator under each work Phase.

B. Each Task Authorization issued by the District Professional Services Administrator shall describe the scope of services to be performed, the steps required, the number and location of bridges, and the estimated fees to be paid for the Task. No payment for work performed shall be authorized for the Consultant until a Task Authorization has been issued.

C. The last task assignment shall occur no more than two years after the award date of


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this contract.


existing bridge scour scope 12-29-04(2)

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