Instruction for installing shafts
Shafts with preformed channel base are distinguished by low weight and simple installation
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Step 1: Preparation of the construction pit
When installing the inspection shaft made of polyethylene, it is necessary to excavate a construction pit of the appropriate size, so that it is possible for the worker to approach it for making connections and adjusting the falls.
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Step 2: Preparation of the bed
The inspection shaft must be placed on a suitable bed. This must be hard and compact and made with suitable backfilling material.
The material for making the bed can be round-grained with a grain size of 0 - 32 mm, or crushed material with a grain size of 0 - 32 mm. Frozen material is not suitable for use.
It is necessary to prepare the bed from the appropriate material in a thickness of 15-20 cm and compress it to a compaction of 97% according to Proctor. In the case of underground water, it is necessary to make a bed of lean concrete MB15 for the shaft.
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Step 3: Installation and adaptation of the shaft to the terrain
The shaft can be installed manually or with the help of construction machinery - an excavator. When lifting the shaft with machinery, lifting lugs are integrated on the cone of the shaft. We adjust the shaft in the construction pit accordingly to the terrain. When inserting the shaft, we must pay attention to the protruding parts, so that the coupling or stud on the shaft does not break off.
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Step 4: Backfilling of the shaft
Backfilling the shaft requires the use of suitable backfilling material. The material suitable for backfill can be round-grained with a grain size of 0-32 mm, or crushed material with a grain size of 0-32 mm. Frozen material is not suitable for use.
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Step 5: Design of cast iron cover
Before the implementation of the relief plate and the installed LTŽ cover, the use of heavy construction machinery is not allowed in the immediate vicinity of 1 m from the shaft.
The relief plate is placed on the backfill material, which should be at least 0.4 m larger than the diameter of the shaft. (example: Shaft DN 600 – relief plate or AB ring at least 1000 mm.)
With this, the loads are transferred to the reinforced backfill in the vicinity of the shaft and not directly to the inspection shaft.
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Step 6: PE cover design
To construct a manhole with a PE cover, it is necessary to fill the manhole with backfill material up to the last 20 cm of height. An adapter with a cover is placed on the neck of the shaft and filled with existing soil or other pressure. This cover is not suitable for driving. The load carried by the PE cover is up to max. 200 kg.
