Fracture-Critical Bridge Splice Under D1.5
A bridge fabricator is making a complete-joint-penetration groove weld splice in a 25 mm flange of a fracture-critical member to AWS D1.5. The WPS is qualified, but the CWI notices the backing is removed and the root is back-gouged, and the UT report shows a few small indications near the root. The fabricator wants to accept based on 'UT passed.' The CWI must determine whether the inspection is sufficient for a fracture-critical member, whether the indications are acceptable, and what additional requirements apply.
1. What inspection requirements apply to a fracture-critical CJP groove weld under D1.5?
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Fracture-critical members require 100% volumetric examination of CJP groove welds, typically UT, plus visual inspection. D1.5 also imposes stricter requirements on welding procedure qualification, welder qualification, and inspection than D1.1. The CWI should confirm: (1) the WPS and PQR meet D1.5; (2) welders are qualified per D1.5; (3) UT is performed by qualified personnel per the referenced standard; (4) the acceptance criteria applied are the D1.5 fracture-critical criteria, which are more restrictive than routine D1.1 criteria; and (5) the inspection report identifies the specific acceptance standard and revision. 'UT passed' is insufficient without the acceptance criteria and indication details.
2. How should the CWI evaluate the root indications?
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The CWI should obtain the UT report details: indication amplitude, length, depth, and location relative to the weld. For fracture-critical welds, the acceptance criteria are tighter; small indications that might pass in a non-fracture-critical weld may be rejectable. The CWI should compare each indication to the D1.5 acceptance table, confirm the UT technique and calibration, and verify the indications are not crack-like. If any indication is crack-like or exceeds limits, the weld must be repaired and re-examined. The CWI should not accept based on a summary statement alone.
3. What documentation and hold points should the CWI enforce?
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The CWI should enforce hold points before welding (WPS/PQR/welder quals verified), during welding (parameters monitored), and after welding (visual, UT, and any required MT/PT). Documentation should include: weld map with unique IDs, WPS number, welder ID, date, UT report with indication details and acceptance criteria, repair records, and final sign-off. The CWI should also verify that the fabricator's quality program addresses fracture-critical traceability and that records are retained per contract.