Technical_Specifications.pdf

TECHNICAL SPECIAL PROVISION

FOR

MOVABLE BRIDGE CONSTRUCTION

MAIN STREET BRIDGE REPAIRS - CLEANING AND PAINTING

BRIDGE NO. 794004

This item has been digitally signed and sealed by Natalie Rodriguez on the date adjacent to the seal. Signature must be verified on any electronic copies.

Professional Engineer: Natalie Rodriguez, PE #70945 Date: June 24, 2026 Firm Name: GFT Infrastructure, Inc.

Firm Address: 3230 W. Commercial Blvd., Suite 450

Fort Lauderdale, FL 33309 Cert. of Authorization: 5564 Pages: 1-9 nmrodriguez

TABLE OF CONTENTS

T465-1. GENERAL

T465-1.1. Description T465-1.2. Standards T465-1.3. Field Measurements and Surveys T465-1.4. Products T465-1.5. Quality Control T465-1.6. Submittals

T465-2. COUNTERWEIGHTS AND BRIDGE BALANCING

T465-2.1. Description T465-2.2. Materials T465-2.3. Construction Requirements

T465-3. METHOD OF MEASUREMENT

T465-4. BASIS OF PAYMENT

SECTION T465 - MOVABLE BRIDGES

T465-1. GENERAL

T465-1.1. Description

Execute movable bridge work in accordance with the Contract Documents.

T465-1.2. Standards

Portions or all of certain recognized industry or association standards or specifications referred to as a requirement in these Technical Special Provisions are to be considered as binding as though reproduced in full unless supplemented and modified by more stringent requirements of the Contract Documents. Unless otherwise stated the reference standard or specification, which is current at the time the Contract Documents are sent out for solicitation, will apply.

T465-1.3. Field Measurements and Surveys Conduct field surveys to verify existing dimensions shown on the plans, prior to development of submittals. Identify field verified dimensions on submittals. Conduct field measurements and surveys as required to supplement information provided in the plans and as necessary to provide a complete and satisfactory fitting and operational installation.

T465-1.4. Products Provide materials and equipment meeting the requirements of this TSP. Where particular products are called for, provide said products unless otherwise approved by the Engineer.

T465-1.5. Quality Control Perform all work under this Technical Special Provision in accordance with an approved Quality Control Plan meeting the requirements of FDOT Specification 105.

T465-1.6. Submittals T465-1.6.1. General Shop Drawings:

1. Refer to FDOT Specification 5.

2. Mark standard drawings showing more than one model or size, to indicate the model or size proposed.

Samples: Refer to FDOT Specification 6.

T465-1.6.2 Product Data Submit data for products following the requirements of FDOT Specification 5-1.4.4.

T465-2. COUNTERWEIGHTS AND BRIDGE BALANCING

T465-2.1. Description T465-2.1.1. Terminology The terms “counterweight adjusting blocks”, “counterweight balancing blocks”, “counterweight blocks”, “adjusting blocks”, and “balance blocks” are used interchangeably.

The terms “balance state” and “balance condition” are used interchangeably.

T465-2.1.2. Requirements for Balance States Properly balance the bridge for all angles of operation. Consider the properly balanced condition for the bascule leaf as follows:

A. Ensure that the bascule leaf is unbalanced toward the channel (tip heavy) by a force at the toe between 1,500 and 2,000lbs with the bridge in the lowered (closed) position.

B. Center of gravity of the leaf forward of the centerline of rotation (trunnion) of the leaf with an alpha angle between a minus 20 degrees and 20 degrees. The alpha angle is defined as the angle of elevation of the center of gravity of the leaf above (minus being below) the horizontal axis through the centerline rotation of the leaf. Location of the center of gravity within this range will yield a closing imbalance moment for the full rotation of the leaf, with larger imbalance being near the fully closed position and smaller imbalance at the fully open position of the leaf. This will provide good holding of the leaf and contact of limit switches to close the leaf from open position under imbalance.

Required Interim Balance State: During the course of construction and for conditions where the leaf is not secured with tie-down devices, the maximum permitted imbalance requirement is indicated in Paragraph A (above). The Engineer may consider an imbalance outside this range acceptable for specific operations. For such operations, submit detailed request along with calculations completed in accordance with Specifications to the Engineer for review and approval.

T465-2.1.3. General Scope of Work A. General: The work specified in this Section is required for the bascule span; items are not necessarily listed in the order of occurrence.

B. Develop and submit counterweight computations and finalized counterweight configuration.

C. Develop and submit Leaf Balancing and Stability Plan.

D. Furnish and place cast-iron counterweight adjusting blocks for final balancing or temporary ballast as required for achieving balancing.

E. Achieve and maintain acceptable interim balance states for the bascule leaf throughout the course of the work.

F. Achieve an acceptable final balance state for the bascule leaves upon completion of the work.

G. Furnish and install Span Balancing Test Gage Assemblies and perform testing as needed.

H. Field survey and document final dimensional configuration of adjusting blocks in the counterweight pockets. Inventory all counterweight pockets.

T465-2.1.4. Work Restriction and Requirements A. Meet the requirements of FDOT Specification 7 and 103.

B. Maintain a Balanced Leaf Condition at all times.

C. The use of span locks as a tie-down device or as a supplement to a tie-down device is not permitted.

D. Installation of a steel ballast piece is not permitted until the Engineer has received certified dimensions and shipping weight for that individual piece to be installed in the leaf.

T465-2.1.5. Quality Assurance Counterweight Computations: Provide signed and sealed counterweight computations and shop drawings.

Computations for Tie-Down Devices: Provide signed and sealed computations and shop drawings.

T465-2.1.6. Shop Drawings A. As a minimum, submit the following for review and approval: Shop drawings for cast-iron counterweight adjusting blocks; provide weight of block; product data for coal tar epoxy coating for cast-iron blocks.

B. Counterweight Computations:

1. Submit detailed counterweight computations and shop drawings for interim leaf configurations and interim balance states.

2. Submit detailed counterweight computations and shop drawings for the final leaf configuration and final balance state.

3. Provide all counterweight shop drawings and counterweight computations signed and sealed by a Professional Engineer registered in the State of Florida.

4. Counterweight computations are to identify as a minimum, the center of gravity of the following component assemblies: Existing bicycle plates, new bicycle plates and counterweight adjusting blocks.

5. Use weights from approved structural steel and machinery shop drawings for computations.

6. At the completion of Balance Verification Testing, submit revised erection drawings documenting the final configuration of adjusting blocks in the counterweight pockets.

C. Span Balancing (Interim and Final): Submit description of proposed equipment to be utilized, proposed balancing procedures, and proposed reporting forms.

D. Leaf Balancing and Stability Plan:

1. Prepare and submit a Leaf Balancing and Stability Plan for the leaf.

2. Outline proposed leaf stability for the duration of the project.

3. Specifically address each element of the Work associated with the leaf and the machinery of the leaf that will affect the balance and stability of the leaf and the proposed measures that will be taken to ensure balanced and stable leaf conditions throughout the duration of the Work.

4. Submit supporting shop drawings and counterweight computations.

5. Balance State Report:

a. Submit for final balance state after all work on the leaf is complete but prior to Balance Verification Tests.

b. As a minimum, the balance state reports must contain the following:

Geometric parameters for equating pressure/torque and imbalance moment, pressure/torque measurements with associated leaf positions, accompanying weather, wind, and temperature measurements, quantification of the location of the center of gravity of the leaf, inventory of the counterweight pockets, summary and conclusions, and Signed and Sealed by Professional Engineer registered in the State of Florida.

T465-2.1.7. Balance Calculations

A. Perform balance calculations for the bascule leaf. Compute the balance calculations in two phases: Phase 1 - Preliminary Balance Calculations using existing balance data, including adjustments for each phase of work and the end balance for each leaf and Phase 2 (Final Balance Calculations) using measured weights for the existing and new structural steel. Ensure the calculations are prepared, signed and sealed by a Professional Engineer registered in the State of Florida. In order to permit detailed checking, prepare these calculations as detailed below.

B. Allowance is required for the weight of paint.

C. Compute weights of individual components to the nearest 0.1 lb accuracy. Summarize weights of assemblies to the nearest 1.0 lb accuracy. Summarize Bascule Leaf weight to the nearest

0.1 kip accuracy.

D. Locate the Center of Gravity (C.G.) of each component or assembly of components both horizontally and vertically.

1. Reference the C.G.’s longitudinally to the center of rotation:

a. Positive (+) distances are recorded for elements forward of the trunnion (i.e., toward the channel).

b. Negative (-) distances are recorded for elements behind the trunnion.

2. Reference the C.G.’s vertically to the center of trunnions:

a. Positive (+) distances are recorded for elements above the trunnion.

b. Negative (-) distances are recorded for elements below the trunnion.

Record distances to components or assemblies to the nearest 0.010 foot of accuracy.

E. In computing the vertical distances to the C.G.’s of the components, account for the vertical geometry of the bascule leaf.

F. Summarize the computations in tabular form with components and/or subassemblies grouped together.

G. Report the weight and C.G. of each component as follows:

1. Weight, W in kips (to the nearest 0.01 kip).

2. Distances from center of trunnions to C.G., X (horizontal) and Y (vertical) in feet (to the nearest 0.010 ft).

3. The component contribution to unbalance torque in kip-ft shown as the products W*X and W*Y (to the nearest 0.1 kip-ft.).

4. Add the component weights and unbalanced torques to produce totals for each Bascule Leaf.

H. Report the weight and C.G. of the sum total of all components for each Bascule Leaf in terminology as follows:

1. Weight, W in kips (to the nearest 1.0 kip).

2. Distances from center of trunnions to C.G., X (horizontal), Y (vertical) and L (radial) in feet (to the nearest 0.010 ft).

3. Angle, α, between a horizontal line through the trunnion axis and a line from the trunnion axis through the C.G. of the Bascule Leaf in degrees (accuracy to 0.010 degrees). The angle is measured positive (+) upwards from a horizontal line extending forward (toward the channel) of the trunnion axis.

4. The net Bascule Leaf unbalance torque as the products, W*X, W*Y, and W*L, and the leaf unbalance torque, T = W*L*cos(θ +α), shown at ten degree increments of leaf angle, θ.

T465-2.2. Materials T465-2.2.1. Counterweight Blocks (Cast Iron) Cast-iron Blocks:

A. Material: ASTM A48 or equivalent.

B. Unit Weight: Minimum 450 lb/ft3.

C. Protective Coating: Coal Tar Epoxy: Abrasive blast and apply one coat of coal tar epoxy coating minimum 8 mils dry film thickness. Optional: Hot-dipped galvanized in accordance with

ASTM A153.

T465-2.3. Construction Requirements T465-2.3.1. Notifications Notify the Engineer a minimum of 28 days prior to the date that is anticipated that the final Balance Testing is going to be performed.

T465-2.3.2. Counterweight Adjusting Blocks Fabricate counterweight adjusting blocks only after approval by the Engineer of the appropriate counterweight computations as specified elsewhere in this Technical Special Provision.

Place and arrange blocks throughout the course of the Work as required for achieving or maintaining acceptable balance states.

T465-2.3.3. Span Balancing - General A. For final and intermediate balance states, obtain chart recorded strain gauge based torque, imbalance and friction data, for a minimum of three cycles of the leaf. The intent is to obtain three measurements at each angular position, the second and third measurement being made after the leaf is cycled back to the closed position.

B. Given the numerous variables that may have an effect on the values of the torque measurements, schedule testing generally as follows in order that measurements taken on one day may be better correlated with measurements taken on another day:

1. In the morning at sunrise so as to minimize the differential in ambient temperature.

2. At a time with no wind; if wind exists, preferably the wind should not be in a direction along centerline of the bridge.

C. For each torque measurement, obtain and record the following data: Ambient temperature, weather conditions, wind speed and direction.

T465-2.3.4. Maintenance Balance During the Course of Construction Maintain balance in accordance with the Leaf Balancing and Stability Plan.

Verify the condition of balance at time intervals appropriate with the work being performed to ensure a Balanced Condition at all times.

The initial balance state was measured in December, 2024. The results are as follows:

T465-2.3.5. Final Balancing Complete all work on the leaf prior to initiation of the final balancing program.

Perform the final balancing of the leaf; achieve an acceptable final balance state.

Submit Balance Report and arrangement of adjusting blocks by inventorying the counterweight pockets.

T465-2.3.6. Dynamic Strain Gauge Testing Dynamic Strain Gauge Testing includes, at minimum, the following items:

A. Description of experimental procedure including type and method of installation of strain gauge rosettes, method of transmission of low level signals, data acquisition equipment and strip chart recorders.

B. Location plan of span drive equipment showing proposed location of strain gauges, amplifiers, cable or radio links, data acquisition equipment and all associated cabling.

C. Details of method of transmission of signals from shafting to data acquisition units.

D. Elementary wiring diagrams of interconnection of strain gauges, amplifiers, data acquisition equipment and strip chart recorders.

E. Description of electrical and mechanical factors including sample calculations for obtaining shaft torque from measured strains, span imbalance and curve fitting and basis for friction correction.

F. Mount adhesive bond foil strain gauge rosettes on the shafts of each rack pinion.

Sufficiently clean the areas of the shafts where the gauges are to be mounted to remove all contaminants.

Mount two rosettes on each main pinion shaft at 180° from each other. Connect the two gauges such that any direct shear forces in the shafts are neglected and true torsional shear is measured.

G. Connect the gauge leads on each shaft to a four arm amplifier securely mounted to the shaft. Transmit the signals from the shafts to the data acquisition equipment either through cable links wound on spring operated cable reels with sufficient capacity and torque or through wireless transmitters.

H. Connect the output loads from each channel of the amplifiers in each shaft to a strip chart recorder with at least ten inch wide chart paper. Provide the strip chart recorder with an event marker connected to sensors on the pinion shaft such that increments of pinion shaft revolutions are recorded. Interpret each increment as opening angle utilizing the gear ratios of the machinery. Provide a step-wise adjustable chart speed and include a setting of at least 10 inches per minute.

WL Alpha Tip React

Fully Seated

Average Friction

(kip-ft) (degrees) (kips) (kip-ft)

104.34 16.5 1.493 22.364

WL Alpha Tip React

Fully Seated

Average Friction

(kip-ft) (degrees) (kips) (kip-ft)

71.106 21.4 0.988 50.15

NEAR LEAF DATA

FAR LEAF DATA

I. Record the strains in both main pinion shafts versus leaf angle simultaneously during opening and closing to a suitable scale. Ensure the readings for all main pinions are at the same strain scale and chart speed and recorded during the same span opening.

J. Numerically convert the strains induced in the rack pinion shafts to torque for at least 10 points at equal intervals along the strain plots for both opening and closing. Process this data to give a curve of torque for the full travel of the leaf versus opening angle, corrected for friction.

K. Submit a full report documenting the results of the strain gauge tests. The reports shall contain as a minimum the following:

1. Description of experimental procedure and equipment used.

2. Span drive diagram showing location at which strain gauges and event markers were attached and all applicable gear ratios. The diagram to be generated using CAD.

3. Photocopies of original strip charts for both leaf opening and leaf closing for all rack pinion shafts. On the strip charts show the full load motor torque.

4. Description of relationships and sample calculations for obtaining rack pinion shaft torque from strains, span imbalance moment from pinion shaft torque and curve fitting and basis for friction correction.

5. Fitted curves of torque versus opening angle during opening and closing for each rack pinion shaft.

6. Curve of shaft torque versus opening angle corrected for friction.

7. Discussion of probable error.

8. Discussion of results

9. Conclusions

10. Alpha angle, Imbalance, friction, but in terms of leaf torque and reaction at the toe.

11. Provide commentary on the strip chart noting if the control system is set up correctly, i.e. are the acceleration and deceleration times appropriate, is the leaf operating in a steady state manner, is the leaf holding the seating torque.

12. For the final balance report inventory the counterweight pockets and include the layout of the balance blocks in the report. The layout to be generated using CAD and to provide the dimensions of the counterweight pockets, location of the counterweight pockets relative to the center of rotation and amount and quantity of balance blocks. Provide photos of all counterweight pockets.

13. Include in the report an introductory section incorporating the name of the bridge, the shafts tested, the date of the test, weather conditions during testing, and any other information requested by the Engineer.

T465-2.3.7. Acceptance and Final Documentation Testing that verifies that a leaf is in an acceptable final balance state is the basis that the leaf is acceptable with respect to balancing.

Obtain test results and combine with revised drawings showing final adjusting block configurations; submit as final documentation of the final balance state.

T465-3. METHOD OF MEASUREMENT

A. Counterweights and Leaf Balancing: The work of furnishing, installing, and adjusting the Counterweights and performing the Leaf Balancing as described in this Section will be measured under the following items:

1. Balance Blocks will be paid for as required for final balance, fabricated and furnished to the bridge.

2. All labor and materials required to perform the balancing work, will be paid as a Lump Sum.

T465-4. BASIS OF PAYMENT

Price and payment will be full compensation for all work specified in this Technical Special Provision, including furnishing and installing all equipment and materials.

Payment will be made under:

Item No. 465-3-17 Movable Bridge Counterweight, F&I, Balance Blocks .............. Each Item No. 465-3-50 Movable Bridge Counterweight, Adjust ..................................... Lump Sum