Eastside Catchments Gibraltar

Following rockfall in 2015 Golder Associates undertook a design for rockfall mitigation measures to protect the road and residential properties below. The detailed rockfall analysis showed a requirement for protection from a 5000 kJ impact with a system height of 7 m.

In December 2016 CAN Geotechnical were awarded the project to complete phase 1 of the works, a 40 m long and 7 m high 5000 kJ rockfall barrier. We supplied a RXE-5000 barrier. To enable future works to be completed more easily and without deconstructing the existing fence, we provided a solution for the end post to alllow for this.

Over several years and many projects Geobrugg has worked with both Golders Associates and CAN Geotechncial and a good relationship has developed.  This enabled all of the involved parties to work together to find a cost effective and buildable solution. 

The ground conditions on the eastside catchments are well known and extremly difficut to work within. To enable the works to be completed CAN Geotechnical had to carry out lots of temporary works and to use enlarged concrete bases for the fence posts.  Additionally CAN Geotechnical opted to terminate all ground anchors into reinforced concrete bases with wire rope eyes protruding for connection to Geobrugg U-brakes.

In Januray 2018 CAN returned to site to instal the remaining 48m of barrier.  The customised solution installed on the previous section worked perfectly enabling a smooth instalation and transition between the two barriers.

For this phase of works CAN built upon their knowledge of the ground conditions encountered last time and in conjunction with the designer were able to use a more conventional anchoring solution avoiding the need for the large concrete foundations beams and the temporary soil nailing required in the previous phase. This was no easy task however as it required drilling with a 115mm bit to install R51 Hollow bar, with the requirement to install permanent casing in the upper part to provide extra stability.