 October 2010
How Do We Do It?
Ensuring Our Clients of Structural
Integrity of Their Investment
Part I of III
by a Senior Inspector, Infrastructure Engineers, Inc.
To ensure that our clients receive the utmost in structural integrity of their bridges, Infrastructure Engineers prepares for all aspects, as every situation and structure is different. We pre-plan to ensure all safety requirements dictated by the Occupational Safety and Health Administration, Federal, State, and local authorities are met. We also pre-plan to ensure the safety of the traveling public, our inspectors, and the safety of the structure.
Infrastructure Engineers believes that planning and preparing for a bridge inspection are two very important steps in the process of inspecting a bridge. Careful preparation ensures that there is nothing left to “fall through the cracks.” The preparation and planning phases consist of several different aspects including: the preparation of personnel and equipment, and the review of previous reports and load ratings, to include the types of deficiencies and deterioration.
To be successful during this important phase, there are many questions that must be answered: What type of material is involved? Is it steel, timber, or concrete? Is this structure fracture critical? What tools can we use to give our client the most precise information about their structure? Based on these answers, we can adopt the use of our specialized equipment such as the Resistograph for a timber structure inspection or our Ultrasonic Testing Meter to measure exact section loss on a steel member.
During this preparation phase, we also identify what types of inspections are needed. Our surface supplied diving teams are prepared to inspect the piles in a fast-moving river. Our certified climbing teams can access the members that need close-up investigation due to their fracture critical nature or are otherwise impossible to reach from a lift truck.
The previous report and load ratings are reviewed during this phase and a pre-inspection meeting is conducted with project team personnel. This familiarizes the team with areas of deterioration, preparing them for any findings that may be encountered. The team can also focus on areas with similar details that may have initiation of “like” deterioration.
Infrastructure Engineers does not take bridge closures lightly, so potential critical findings are discussed and a plan of action for a bridge closure is reiterated during the pre-inspection meeting. The equipment needed to close the structure is also loaded and checked for operation. Wallet cards are utilized to provide project team members with a quick reference of phone numbers for local authorities, owners, project managers, and others involved with the structure’s closure.
Our inspection phase consists of deploying the necessary means to provide our client with a precise description of the condition of their bridges. Our teams have the ability to perform a topside inspection with the use of the snooper; while our dive team takes high quality underwater pictures of exposed rebar in black water.
The Infrastructure Engineers inspection teams take a “top down” approach while performing their inspections. The deck is inspected first, in order to identify trouble areas, which are focused on when inspecting the underside of the structure. Previous deficiencies are verified for accuracy of size and location. Any discrepancies or changes are updated, and supported by a high quality photo. New deficiencies are documented with description, exact size, and precise location on the structure. Section loss readings are taken on members with excessive corrosion using our ultrasonic testing equipment. Internal timber decay is precisely measured and graphically depicted through the use of our Resistograph.
If any critical findings are encountered during the inspection, the plan of action discussed in the pre-inspection meeting would begin. Immediate load reductions may be required until further analysis or immediate repairs can be performed. If immediate repairs or load reductions are needed, Infrastructure Engineers will submit a letter of Prompt Corrective Action, or a Bridge Posting Notice to the owner of the bridge, advising them of the conditions observed.
Additionally, while our teams are performing inspections, all repairs and conditions of the repairs are accurately documented and supported with photographs. A determination is made as to the quality of the repair and if the repair impacts the capacity of the structure.
Click Here to Read Part II of III |
