The Roads & Drainage Division of Orange County Public Works in Orange County, Florida is responsible for the routine maintenance and preservation of 106 county-owned vehicular and pedestrian bridges. These bridges fall within the Federal Highway Administration (FHWA) and Florida Department of Transportation (FDOT) Bridge Management System (BMS).
Each of these bridges are inspected once every two years by FDOT consultants, with the exception of those bridges requiring yearly inspections based on specific structurally deficient elements, or due to the fact that accumulated criteria sets them near obsolete. FDOT’s Bridge Structures Inspection Program identifies bridge deficiencies and other structurally deficient issues and/or concerns that are critical enough to endanger public safety. Non-critical deficiencies are also identified in this process, resulting in a Comprehensive Inventory Data Report (CIDR) which is in turn submitted to the county.
As Orange County, of which the authors are members, is responsible for carrying out repair and restoration efforts, its Roads & Drainage Division provides planning, administration, and methodologies for the entire bridge maintenance program.
Bridge inspection reports assign a numerical condition rating to each of the components or items: 0 being the worst, 9 being the best. The Overall Condition Rating for a bridge represents the component or item with the lowest rating. The ratings are divided into four categories as follows:
Excellent (8-9); Good (6-7); Fair (5); Poor (4 or less).
As a bridge owner, Orange County employs the Bridge Management System (BMS) in selecting and performing work that is determined to be the appropriate activity, taking place on the correct bridge, at the right time, and at the right cost. The BMS also helps the county to achieve its bridge performance objectives and goals—and to maximize returns on investment.
There are two families of criteria, or “elements,” that are considered in the overall BMS. National Bridge Elements are the primary structural components of bridges necessary to determine the overall condition and safety of the primary load carrying members. These include various materials and construction types with regard to decks and slabs, bridge railings, superstructures, substructures, bearings, and culverts. Bridge Management Elements include components of bridges such as joints, wearing surfaces, protective coating systems, and deck/slab protection systems that are used for bridge management purposes.
Some of these common elements’ deficiencies are scour, settlement, distortion, loss of bearing areas, alignment, exposed prestressing, movement or rotation, poor or failing connections, seal damage, seal adhesion, debris impaction, corrosion, deterioration, leakage, blockage, exposed rebar, cracking, delamination/spall, patched areas, rust/staining, and abrasion.
Florida DOT reports depict deficiencies as Good, Fair, Poor, or Severe, and identify bridge work categories that include general maintenance, routine maintenance (minor repairs or non-structural), periodic maintenance (major repairs or structural), and bridge rehabilitation.
Maintenance and repair types adhere to a classification system. General maintenance is for nonstructural defects. Minor repairs include spall patching, minor repairs to joints, and bolt tightening. Major repairs are channel modifications, pile jacketing, and other larger works, usually handled by term contracts or through a public bid solicitation process.
Rehabilitations are not considered to be routine maintenance, but rather more advanced repairs to bring deficient bridges up to current standards. Bridge rehabilitation projects are somewhat reactive and based on information from bridge inspection reports. Repairs often include structural activities such as wing wall replacements, beam replacements, and the addition of corrosion control systems.
Work Process Flow History & Strategy
Prior to May 2018, all inspections and CIDR report submittals were managed by Orange County’s Engineering Division in coordination with FDOT. All minor maintenance and routine repair work were sent to Roads & Drainage Division for handling, where the in-house construction section staff under the direction of the Construction Coordinator performed all routine bridge maintenance work. With respect to the major structural deficiencies, this was handled by the Engineering Division directly as a Capital Improvement Project (CIP).
However, the work process flow scenario was changed immediately after this time. A decision was made where the Engineering Division would no longer handle bridge maintenance and rehabilitation duties—except for total bridge replacement.
We were then provided with 72 FDOT CIDR bridge reports that included all major/minor deficiencies, both structural and nonstructural, for handling. Our staff—being a maintenance group with neither a set program nor budget—had now for the first time to deal with the entire bridge maintenance and repairs program. This was an overwhelmig challenge for the division staff. Hence, the division management immediately put in place an emergency funding request and approach process, which initiated an approach to address the 72 FDOT CIDR bridge reports.
In the CIDR reports, core structural issues that needed immediate attention were as follows:
- Cracks on pillar circumference
- Eroded concrete piles
- Pile scouring/Underwater repairs
- Embankment washouts
- Wing wall / Barrier wall rotation
- Bridge approach subsidence
- Deck separation, soffit repairs
- MSE wall repairs
- Voids / loose soils on embankment and slopes preservation
- Critical Structural Repairs
In some cases, reported deficiencies were not clearly described for repair items. Our current in-house bridge crew only carried out routine and minor nonstructural repairs such as (but not limited to):
- Sealing
- Caulking
- Handrail repairs
- Guardrail repairs
- Graffiti removal
- Painting
In some instances, term contract services were employed for repairs of hand rails, guard rails, graffiti removal, and other such activities. However, the current 72 FDOT CIDR bridge reports provided an extensive spectrum of repairs with varied challenges, among which were:
Resource Limitations: The in-house bridge crew has limited resources and could only perform minor repairs such as sealing, caulking, painting, weed removal, patching, and fence and post repairs. This crew was not equipped with scaffolding, boats, long boom utility bucket trucks, floating decks, or barges—any form of equipment needed to perform underwater repairs—nor were they outfitted for road closure maintenance of traffic scenarios, or provided the proper instruments required for major repairs. Watercraft can sometimes be necessary, as well as large lights, scaffolding, or electronic equipment. The ownership and maintenance of all these equipment types incurs additional work and expense.
Training Limitations: The in-house crew did not possess any specialized training to perform structural repairs. Also, the crew was not OSHA trained and certified to work on or under a bridge with specialized harnesses or safety chains/rails. Our in-house crew was not certified to do certain operations due to lack of FDOT, OSHA, and other regulation requirements.
Other Limitations: Special permitting, training, and certification is required for crew members to work on certain bridges that cross state highways, railroads, and waterways.
In looking back at our bridge maintenance progress and having responsibility for maintaining both vehicular and pedestrian bridges within the county, the process flow to facilitate this overall project was updated.
Consulting and Contracting Services
Due to the enormous task of carrying out minor and major repairs for 72 bridges on a very limited budget, we sought advice from FDOT’s consultant to get more knowledge and understanding of the agency’s CIDR methodology and recommendations.
FDOT representatives advised that structural repairs shall be carried out by using FDOT certified contractors—skilled, equipped, and experienced with major structural repairs.
We then planned our repair strategy and took a data-driven approach to project selection that emphasized detailed engineering reviews and priorities as deployment of a uniform process of asset management that looks at true needs and life cycle costs. Establishing and carefully applying standardized metrics to guide project selections for preservation, these repair projects will drive coordination and save money.
We invited Orange County’s existing engineering term consultants to develop a scope of engineering services for each bridge to further identify core engineering issues, both structural and geotechnical, and repair recommendations. Each scope of recommended service was developed to carry out required engineering services for major repairs.
Two consulting engineers were tasked to assess nine bridges that required immediate attention on structural repairs, identify the extent of structural repairs, and prepare design plans and bid documents for solicitation of contractors through an open bid process. Upon bid request, the formal solicitation is provided to prospective bidders. Upon completion of the bidding process, the lowest bidding contractor was assigned to carry out construction work per design plans, as required. Awards in this category could be made by purchase order and as a part of the award, the solicitation, and other supporting documents such as the formal contract.
In some cases, where engineering designs were not required and the construction cost was under $100,000, Public Works obtained a minimum of three written quotations (one of which, if possible, was to come from a certified minority- or woman-owned business enterprise firm) for each item or group of repair items required. A firm’s failure to reply was documented as a no-quote and thus qualified as an attempt toward the three-quote minimum.
Our consultants and structural engineer worked closely with the project team to manage and administer the program, review and inspect deficiencies noted in the CIDR reports, segregate minor from major and structural from non-structural repair recommendations, assist with term contract preparation, coordinate with consulting engineers and contractors, prepare formal bids for the three-quote process, and manage data.
What constituted success was measured by the following:
- Cost-effective management
- Improved consistency
- Accelerated project completion by transferring the risk of time delays.
- Improved project cost and quality.
- Ensuring sustainable maintenance of the bridge over its entire life cycle (including an operations component).
- Fast-tracking technology adoption by allowing consultants/contractors to capture a portion of the gains.
- Promoting creativity to promote efficiency, reduce risks, and accelerate project delivery schedules. This is particularly important for projects that pose complex design and construction challenges.
- Preventing good and fair condition bridges to reach the point of deterioration that they would be reclassified as poor condition bridges.
Looking to the Future
Most bridges built in the past were designed for a service life of 50 years, whereas the industry is now designing bridges to last for more than 75 years. Therefore, a basic factor for evaluating an appropriate repair strategy is to look at bridge age as a method of forecasting long-term budget proposals. Now, this might lead one to conclude that bridges constructed before 1960 are at the end of their service life and should be assessed first for major rehabilitation or replacement, as deemed necessary.
Fortunately, advances in material science, design practices, and construction methods have contributed to many bridges functioning well past their original design life, despite the tremendous growth in traffic volume over the intervening years. The strategy of bridge maintenance is to leverage the aforementioned advances using an aggressive maintenance program to extend the useful life of a bridge, thereby minimizing the need to replace a large number of bridges within a short period of time.
Based on the funding restrictions and other related limiting factors that affect our bridge maintenance program directly or indirectly, our goal in Orange County is to optimize a mix of in-house and contracted resources to maximize effectiveness and efficiency with regard to performance and cost savings. In addition, we are working on an inspection contract in effort to incorporate new technologies, including unmanned aerial systems, which offer a number of potential advantages for specific bridge inspection activities, in that they can make it easier for inspectors and engineers to see some of the most difficult-to-reach sections of bridges with little planning and preparation, and on relatively short notice. Moreover, the use of UAS puts fewer workers at risk, because it reduces the need for workers to climb to high, dangerous, and difficult-to-reach bridge areas as frequently.
The performance of maintenance and repair activities in a timely manner keeps bridges in good condition, avoids more expensive repair or replacement costs in the future, and ensures that the bridges are safe for use by the public. A comprehensive, detailed program of evaluation and recommendation, leading to appropriate action for each bridge’s needs, will see Orange County safely into the future.
