Tricky Trench with lots of Services

Dated: August 2016 Display all Projects
Principal: SCIRT
Customer: MacDow
Location: Sorensens's Place, Phillipstown, Christchurch
Contractor: Macdow
Product: Gripshore Vertishore with Backing Board

At a small Housing NZ development in Christchurch MacDow have been installing drainage pipes using a variety of trench shoring from TSNZ, including KS100 trench boxes, KVL trench boxes and a KVL mini piling frame where they have encountered the odd service crossing the trench.

However, when Macdow encountered multiple services crossings in a small area they turned to TSNZ for a shoring solution. TSNZ saw that this was an ideal application for the new Gripshore Vertishore hydraulic soldier shoring system which TSNZ soures from specialist shoring company MGF in the UK. Macdow chose to use the 1.6m long Gripshore Vertishore soldier rails complete with 500mm wide GRP backing boards.

These soldier sets were easily installed manually by lowering into position using load rated fabric strops supplied by TSNZ, then pumping out to the required pressure to induce a load into the surrounding soil.


Hydraulic soldier shoring systems provide safe shoring even though gaps of up to 1.5m can be left between each set. This is because of the soil arching principal. This occurs when soils are of sufficient strength and cohesiveness to be able to take on and hold a load which is induced by the pressure which is put onto the soldier rails by the hydraulic hand pump. A load of a minimum 400 psi is required in order for this to occur and different loads are required for categories of soil types. TSNZ provide a handy guide for this.


Macdow chose to take 1.6m long rails with 500mm wide backing boards, which are facatory bonded to the rails. These backing boards serve to prevent any loose material from ravelling off the trench walls. This loose material might otherwise be a niusance. Soil arching occurs though regardless of backing boards being used.


Gripshore Vertishore is fast, safe and very effective for working around services in trenches up to 2m deep.

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