Cunningham’s Gap – Completed Reconstruction Program Program Update December 2012

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Ipswich and Brisbane

Warwick and Sydney

Site No.

Location Details of damage Proposed treatment

Top of the Gap Landslip caused topsoil and vegetation to fall away below the road surface. Stabilise landslip with 129 permanent soil nails – completed in October 2011.

Slope located 15 m from the top of the Gap

Cracks and changes to road surface in the east bound lane. Excavate and rock fill embankment with 555 soil nails (345 temporary and 210 permanent) – completed in November 2011.

Slope located 150 m from the top of the Gap

Cracks and changes to road surface in the east bound lane. Excavate and rock fill embankment – completed in September 2011.

Slope located 300 m east of Gap Creek Bridge

Cracks and changes to road surface in the road shoulder and the east bound lane.

Excavate and rock fill embankment with 134 permanent soils nails – completed in December 2011.

West of Fig Tree Gully Cracks and changes to road surface in the east bound lane. Excavate and rock fill embankment with 216 permanent soils nails – completed in February 2012.

Fig Tree Gully Cracks and changes to road surface across all lanes. New retaining structure including 40 piles – completed in February 2012.

West of the truck rest bay Landslip below the road surface. Clean landslip, excavate and rock fill embankment – completed in January 2011.

Clayton’s Gully Cracks and changes to road surface due to embankment settlement across three of the four lanes (approx 2–4 m).

Realign highway away from embankment – completed 2012.

Six Penny Gully Cracks and drop in the road surface across two of the four lanes. Excavate and rock fill retaining structure – completed in February 2012.

West of Stockpile Site (1200 m east of the helipad)

Landslip below the road surface. Clean landslip, excavate and rock fill embankment – completed in February 2011.

National Trail (600 m east of the helipad)

Signs of road surface damage. Excavate and rock fill embankment – completed in December 2011.

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Works completed

Rockfill

Temporary soil nails

Permanent soil nails (up to 15 m long)

← Traffic lane (to Aratula)

Traffic lanes (to Warwick)) →

Rockfill with soil nail solution

Fig Tree Gully – piling solution

Rockfill

Temporary soil nails

Permanent soil nails (up to 15 m long)

Pile (20–25 m deep) anchored to rock under road

Artists impressions are indicative only and not to scale

Gap Creek Bridge