Greg Samchek (AScT), Shoring Manager Cory Yacyshyn Chief Estimator/Project Manager

• Shotcrete shoring using tieback anchors.
• Underpinning
• Pressure Grouting / Slab Jacking
• Shotcrete Applications:
  Excavation Support:
  Channel Linings
  Tunnel Lining.
  Structural & Seismic Upgrade
  Steel and Poly Fibre Shotcrete
  Drymix & Wetmix Shotcrete
  Final wall shoring
  Culvert Rehabilitation
  Shaft Support
  

• Anchor Applications:
Temporary Anchors:
Grout Injected Mai / IBO type
Manta Ray anchors
Strand Anchors
Soilex Expander Base Anchors
Dywidag type threadbar anchors
Williams bolt hollow and solid threadbar
Gewi piles / Anchor

• Permanent Anchors:
  DCP Dywidag / Williams threadbar Anchors
  DCP Strand Anchors
  Metalized / Galvanised Mai or IBO type anchors
  Epoxy coated anchors
  DCP Expander Base anchors / piles
  Mini piles
  Soilex Expanded Base Anchors/Piles
  

• Limited Access / Headroom Drill

The acquisition of our new mini-drill opens up a new dimension of restricted access /low headroom drilling for anchoring in buildings, seismic anchors below existing bridge decks on abutments, remote locations, or soil sampling in tough to reach areas. With 7500 ft.lbs (10,000 nm) torque, this drill while small in dimensions has more capacity than many full sized drills. It can walk through a 2’-6" doorway, and can drill in 7’-2" of headroom. This drill is powered by a silenced hydraulic power pack which can be located some 200’ from the drill, with capability of drilling holes up to 12" diameter , cased, and augered holes.

Shotcrete tied back shoring was developed in Vancouver in the late 1960’s, and the process patented in North America in 1972, and is the commonly used vertical shoring method employed within the City for excavations up to 80’ deep. Generally speaking it utilizes a » 4" shotcrete facing secured by tensioned soil anchors, with weep-holes regularly spaced for drainage. The tensioned anchor system leads to less ground movement than the untensioned soil nailing method. Underpinning is accomplished in a similar fashion, though generally thicker shotcrete, and heavier reinforcing is used.

Sequencing of operations is as figure 1.

Project: Design / Build Excavation & Shoring 400’ x 130’ x 71’ deep (1 city block)

Volume of excavation: 75,000 M³

Area was known to be in bad slickenside area of town with a history of large movements and previous collapse of excavations.

BelPacific worked with our design Engineer, and devised a pre-drill program to identify potentially bad areas, and subsequently reinforce these. In order to monitor movement, 6 inclinometer holes were advanced around the perimeter, and monitored weekly, or daily as required.

In slickenside areas, anchored reinforced concrete caissons were installed to resist sliding.

During construction, movement of up to 75mm. was picked up on one inclinometer, and remedial action was immediately taken to arrest this situation.

1300 WEST GEORGIA
Overall view of project		Anchored caissons
click on picture for larger view
Shotcreting caissons		Final shored caisson wall

This project was completed 2 weeks ahead of schedule.