ABANDONED DN525 WATERMAIN INSPECTION - LOWER HUTT

Client: Hydrotech

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Location: Lower Hutt

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Service: Civil construction

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Date started: August 2022

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Scope of work

Hydrotech needed to CCTV an Abandoned DN525 cast iron Bulk Watermain at three different locations spread along the pipe alignment.

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Solution

Marais Laying NZ proposed using its experienced team with the help of our 8T and Class 4 Trucks to provide inspection pits (10 metres long * 2 metres wide * 1.8 metres deep) and cut in points to facilitate the bulk water main inspection for Hydrotech technicians.

Due to very similar bulk water main in the same area, we had to use a Caliper to identify the correct DN525 cast iron.

Note that the detection of the existing services was made by our GPR locator.

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Results

Marais Laying NZ has been successful providing three inspection pits for Hydrotech. The inspection pits were made safe with trench shields and the ground water was successfully removed with our dewatering system in place (pump + sediment tank).

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Key facts:

• Location of existing services before starting the excavation

• 3 inspection pits (10 metres * 2 metres * 1.8 metres)

• Dewatering system (pump + sediment tank)

• Trench shield on site for the whole project

• Work carried out in the busiest street of Lower Hutt

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Key equipment used:

• 8t excavator

• Class 4 Trucks

• Hydro vacuum truck

• Dewatering system

• Trench shield

• GPR locator