Drainage Flume Installation


Drainage Flume Installation

The AFC design was to install a flume drainage system, incorporating a fin catchment filter drain that would run along the top of the embankment and catch the troublesome pooling water, then into a HDPE crest chamber. The drainage would then turn 90° and travel diagonally down the embankment through a carrier pipe, then into a toe catchpit type chamber before an outfall into the existing track drainage gully.

The site of work proved a very difficult environment for access due to its positioning within dense woodland.  The route to site was through private land and along woodland paths, finally across a narrow wooden decked pipe bridge structure. Due to the dense woodland and narrow access structure the use of heavy plant was not possible, all materials and tooling would need to be transferred onto site by hand.

Due to the poor underfoot conditions Seva decided to install temporary safe access stairs to allow the safe access & egress between the embankment crest & toe.

Works progressed with the installation of the drainage components with the correct levels checked throughout the installation to confirm the correct falls of the pipes, the installation was also checked against the Inspection and test plan as it progressed, with all hold, check & witness points adhered to and confirmed for design conformity.

25 tonnes of aggregate had to be delivered and installed by hand using wheelbarrows. Cumbersome materials such as the HDPE chambers were also delivered to site by hand.

Once the drainage system was installed the existing embankment anomalies that had been created by the fault were stabilised and re-profiled with compacted aggregate and existing spoil.

The existing gully had a bituminous lining applied at the outfall point and a GRP waffle Board was installed to protect the outfall back drop pipe into the gully.

The boundary fence had become unstable due to the existing foundations being washed away, Seva realigned the fence and installed new post foundations.

All materials and tooling were removed from site and the boundary fence was re secured with snap off security bolts.

As there was a small amount of excess aggregate left over Seva used the material to improve the public footpaths that had eroded over the years and required some maintenance to improve the underfoot conditions.

The works were completed on time and within budget.

All pre, during and post inspections by the clients were successful.

All residents were happy with the general conduct of the Seva team, good house keeping and respect for the neighbouring residents and members of the public throughout.

All hand back documentation was submitted successfully to the client.