On July 24, 2023, a Scarborough RT (Line 3) train derailed just south of Ellesmere Station in Toronto. Gannett Fleming was engaged by the Toronto Transit Commission (TTC) to complete a forensic assessment and retained HAL Group Inc. for materials testing, with Abbas Haghbin, P.Eng., serving as the investigation’s Material Testing Lead.

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INVERT SLAB CORING

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On August 1, 2023, HAL extracted five concrete cores from the guideway invert slab at the locations where the reaction rail anchor bolts had been dislodged.

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CORE EXAMINATION AND TESTING

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Each core was photographed, logged, sawn along its full length and tested for carbonation depth, documenting the anchor holes, the remaining expansion sleeves and the quality of the surrounding concrete.

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ANCHOR FAILURE ANALYSIS AND ROD TESTING

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A second phase covered a failure analysis of two anchors and testing of six anchor rods, four replacement rods and two original Hilti rods, to compare the original and replacement anchorage.

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INFORMING THE FINDINGS

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HAL’s results fed into the forensic assessment issued in October 2023, which traced the derailment to reaction rail anchor failures and recommended testing of post-installed anchors along the line.