For construction managers, field engineers, and inspectors working on bridge and infrastructure projects, the proper installation of precast concrete girders is a critical path activity. Errors in handling, setting, or securing these massive components lead directly to costly rework, schedule delays, and significant safety hazards. ANSI\/ASCE CI 67-17, “Design and Construction of Girders for Precast Concrete Bridge Decks,” provides the definitive operational framework to manage these risks. This guide translates its core requirements into actionable, on-site procedures, moving from the yard to final placement.<\/p>\n
In practical terms, this standard is your comprehensive field manual for precast girder projects. It is not a design textbook but a set of enforceable rules for what happens after the girder leaves the casting bed. Field professionals encounter it when: It fills the operational gap between the structural design drawings and the physical, safe installation of the girders, ensuring all field activities align with the designer’s assumptions.<\/p>\n This standard directly addresses high-stakes field challenges: The standard’s power lies in its specific, actionable directives for field crews. Key operational highlights include:<\/p>\n 1. Handling and Erection Procedures (Beyond the Crane Lift):<\/strong> 2. Bearing Seat Preparation & Girder Setting:<\/strong> 3. Temporary Bracing and Stability:<\/strong> 4. Grouting of Bearing Assemblies:<\/strong> ANSI\/ASCE CI 67-17 is widely referenced in US Department of Transportation (DOT) specifications and many municipal bridge codes. Compliance is often a contractual mandate. Who Uses This On-Site:<\/strong> Erection superintendents, rigging foremen, crane operators, field layout engineers, and quality control inspectors. It is used during pre-lift “job hazard analysis” meetings, daily pre-lift briefings, and the real-time inspection of each placement operation.<\/p>\n On-Site Risks of Ignoring CI 67-17:<\/strong> Use this as a field verification guide for each girder or girder line:<\/p>\n Phase 1: Pre-Lift (In the Yard & On-Site)<\/strong> Phase 2: During Placement<\/strong> Phase 3: Post-Placement & Grouting<\/strong> A field engineer on a highway overpass project uses CI 67-17 when the second girder in a line is being set. Following the standard, the crew installed lateral braces on the first girder immediately after its placement. As the crane swings the second girder into position, a sudden gust of wind exerts lateral pressure on the first girder. Because the mandated temporary bracing is already in place, the system remains stable, preventing a potential chain-reaction collision. The engineer references the standard’s wind load provisions in the daily report, justifying a work stoppage until winds subside, ensuring continued safe operations.<\/p>\n 1. “The girder is stable on its bearings, so we can brace later.”<\/strong> FALSE. CI 67-17 requires immediate temporary bracing for stability during the construction phase<\/em>, which is a different condition than the final, permanently decked state. Wind and construction loads before deck placement are a major hazard. By treating ANSI\/ASCE CI 67-17 as an essential field operations manual, construction teams transform a high-risk activity into a controlled, repeatable, and compliant process, safeguarding personnel, the project schedule, and the long-term integrity of the structure.<\/p>\n\r\n
\n* Construction Managers<\/strong> develop lift plans, rigging procedures, and sequence-of-operation documents.
\n* Field Engineers<\/strong> verify bearing seat preparations, oversee girder alignment, and manage grouting operations.
\n* On-Site Inspectors<\/strong> check temporary bracing, confirm proper bearing pad installation, and validate that all installation tolerances are met before the project proceeds.<\/p>\nCore On-Site Problems Solved by CI 67-17<\/h3>\n<\/p>\n
\n* Preventing Girder Damage During Handling:<\/strong> It provides rules for lift points, rigging angles, and temporary stresses to avoid cracking girders before they are even set.
\n* Ensuring Structural Stability During Construction:<\/strong> It mandates specific temporary bracing and support requirements to prevent girder rollover or collapse before the deck is cast and the system becomes composite.
\n* Achieving Final Design Geometry:<\/strong> It sets enforceable tolerances for girder placement (line, grade, and cross-level) to ensure the finished deck profile and alignment meet specifications.
\n* Standardizing Bearing & Connection Details:<\/strong> It offers clear protocols for preparing bearing seats, installing elastomeric pads or other bearings, and grouting sole plates to ensure uniform load transfer.<\/p>\nKey On-Site Technical & Safety Requirements<\/h3>\n<\/p>\n
\n Lifting Hardware Verification:<\/strong> It requires that all lifting devices (loops, inserts) be proof-tested and certified <\/em>before* use, not assumed to be adequate based on design.
\n* Detailed Lift Plans:<\/strong> Mandates that erection sequences account for wind loads, crane positioning, and temporary stability, moving beyond simple crane capacity calculations.
\n* Temporary Support Design:<\/strong> Requires that falsework, cribbing, or temporary piers used to support girders before deck placement be designed for all construction loads, including impact, and inspected before use.<\/p>\n
\n This is a critical verification point. The standard emphasizes that the bearing seat surface must be clean, sound, and at the correct elevation and orientation <\/em>before* the girder is lowered. A common pitfall is trying to “fix” seat issues with grout after the multi-ton girder is in place.<\/p>\n
\n A unique and mandatory control point<\/strong> is the requirement for lateral temporary bracing. Unlike some older practices, CI 67-17 typically requires positive lateral restraint (e.g., diagonal braces or a tied system) to be installed <\/em>immediately* after girder placement and before releasing the crane. This prevents rollover during subsequent girder placements or from wind loads.<\/p>\n
\n* Provides step-by-step guidance on grout material properties, formwork, mixing, placement, and curing to ensure full bearing between the girder sole plate and the masonry bearing plate, preventing point loads and corrosion.<\/p>\nRegulatory Context and On-Site Compliance<\/h3>\n<\/p>\n
\n* On-Site Workflow Integration:<\/strong> Third-party inspectors will use this standard as their primary checklist during girder erection operations. The required documentation\u2014lift plans, rigging certifications, temporary support calculations, and inspection reports\u2014becomes part of the permanent project record for regulatory audits and permit closure.
\n* Comparison with Regional Practices:<\/strong> While the end goal is similar, CI 67-17 is often more prescriptive than older, experience-based field methods. For example, it formalizes the temporary bracing requirement that may have been left to “standard practice” in the past, providing a clear, defensible standard for inspectors to enforce.<\/p>\nTarget Field Professionals and Risks of Non-Compliance<\/h3>\n<\/p>\n
\n* Catastrophic Structural Collapse:<\/strong> Inadequate temporary bracing can lead to girder rollover, causing fatalities, equipment destruction, and project shutdown.
\n* Major Rework and Delay:<\/strong> A girder set on an unprepared bearing seat or damaged during lifting may need to be removed and replaced\u2014an operation costing hundreds of thousands of dollars and weeks of delay.
\n* Long-Term Performance Failure:<\/strong> Improper grouting or misalignment can lead to premature bearing deterioration, water infiltration, and reflective deck cracking, resulting in liability claims years after project completion.<\/p>\nStep-by-Step On-Site Implementation Checklist<\/h3>\n<\/p>\n
\n* [ ] Verify certification of all lifting hardware (loops, straps, spreader beams).
\n* [ ] Confirm crane capacity charts account for rigging weight, girder weight, and planned radius.
\n* [ ] Inspect bearing seats on pier\/abutment: check elevation, cleanliness, and anchor bolt placement.
\n* [ ] Have approved temporary bracing hardware on deck and ready for immediate installation.<\/p>\n
\n* [ ] Conduct final pre-lift briefing with entire crew (crane operator, riggers, connectors, surveyor).
\n* [ ] Guide girder slowly to seat; avoid impact. Use drift pins for alignment, not crane force.
\n [ ] Critical Step:<\/strong> Install lateral temporary braces as soon as girder is stable and <\/em>before* fully releasing crane load.
\n* [ ] Surveyor verifies final line, grade, and cross-level meets CI 67-17 tolerances (typically \u00b11\/4″ on location and elevation).<\/p>\n
\n* [ ] Install grout forms\/seals around bearing assembly.
\n* [ ] Use non-shrink, high-strength grout mix as specified. Ensure proper water ratio and mixing.
\n* [ ] Place grout from one side to allow air escape, ensuring complete filling.
\n* [ ] Protect grout during cure period (e.g., from freezing or drying too quickly).<\/p>\nReal-World On-Site Scenario<\/h3>\n<\/p>\n
Common On-Site Misconceptions<\/h3>\n<\/p>\n
\n2. “If the bearing seat is a little high, we can just grind the girder bottom or use more grout.”<\/strong> FALSE. Correcting seat elevation is a pier modification activity. Attempting to compensate after placement compromises bearing integrity. The standard requires seat verification prior<\/em> to girder setting, forcing the issue to be corrected correctly the first time.<\/p>\n\r\n
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