Redundant Manholes

Aarsleff Pipe Technologies’ methods for sealing of manholes no longer in use are based on the most state-of-the-art CIPP Lining technology. Today, we can seal all types of manholes effectively. Whether or not the main pipe has already been renewed by means of Aarsleff CIPP Lining.

When we seal up a manhole by means of Aarsleff CIPP Lining, we often leave a possible through-going CIPP Lining in the main pipe unopened in connection with the manhole in question. If the main pipe is not through-going, then we install a new short CIPP Lining in the main pipe. This installation is carried out from the manhole to be sealed up.

Subsequently, we fill the manhole with sand or concrete depending on the dimension of the manhole. Regardless of which method we use, we ensure an efficient manhole sealing up. If a manhole possibly has to be reopened later on, then we use sand as fill material.

Prior to filling of concrete or sand, we remove any possible cones. This provides us with as much space as possible in the manhole. Also, we drill holes in the benching or manhole wall to let infiltrated water out thus keeping the groundwater table of the manhole at the same level as that of the groundwater table outside the manhole. Then we fill the manhole with concrete or sand. If we use sand, then this is to be compacted to avoid subsidence damage. Finally, we reinstate the paving. The manhole has now been sealed effectively.

 We recommend that manholes measuring less than one metre are filled with concrete, as sand compaction is not possible for small manhole dimensions.