The Project consists of the execution of a new road to link the towns of Agaete and Aldea de San Nicolás, improving travelling times and user safety. The standard section of the road is of two 3.5 metre lanes, with hard shoulders of 1.5 metres, except in two sections in tunnels, where a further lane is incorporated, to undertake the splitting off of the Gran Canaria road towards the tourist zones located to the south-east, with a length of 6.30 km. The section will be dual carriageway with two 3.5 metre lanes each, and a varying width median.
Due to the irregularity of the terrain to be crossed, in the original project it was foreseen that seven pairs of tunnels would be built, representing a total length of about 8,000 metres of the total 12,600 m (6,300 for each direction), meaning approximately 60% of the route in tunnels. Furthermore, three viaducts were foreseen which represent around 9% of the total length.
The Modified project arises from the need to meet the following requisites, arising during the execution of the work:
- Improve the environmental conditions of the original project, eliminating exits from the road to the two ravines of archaeological and environmental value (Medio Almud and del Cura), modifying the ground elevation and maintaining the route on the ground plan.
- As a consequence, four pairs of tunnels will be built, joining the three intermediate pairs of tunnels which link the Tauro and Taurito ravines into one sole pair, with approximately 2,500 m for each tube, eliminating the effect on the above-mentioned ravines. Likewise, the route carried by viaducts is reduced, and now two bridges will be built, representing about 7% of the length.
- Adaptation of the cross drainage works: the publication of the calculated flow rate for the cross drainage by the GRAN CANARIA ISLAND WATER COUNCIL (the competent authority on hydrological matters), with notable variation in those flows with respect to the original project, the decisive flows being those in the El Lechugal Ravine and in the Mogán Ravine, forces reconsideration of the complete set of works to create cross drainage in each ravine, giving justification from the hydraulic and structural point of view for the solutions adopted for each case.
- Modifications in the Mogán Viaduct: in order to improve the ravine from an environmental point of view and adapt the water course to the new flows, the structure of the ravine is modified, eliminating the embankment at the exit of the tunnel, and changing the type of channelling from tri-cellular frame to “open course”, extending at the same time the viaduct by the execution of the branch roads which join the current road.
- Recalculation of the tunnel sections: due to the new heights of lining of the tunnels affected by the change of elevation, these sections have been recalculated, creating a new catalogue of standard sections based on the rock mass rating of the terrain and which is applicable to all of the tunnels.
Facilities
- In the original project, different facilities were foreseen, amongst which, internal tunnel lighting, ventilation, fire prevention, 6 transformation centres, with alternative of 6 electricity generators, safety facilities for tunnels: loudspeakers, CCTV, SOS posts, incident detection, adaptation of supervision and communications centre. All of this called for an installed power capacity of 6,205 KW with 6 20 KV network supply points from the supply company.
- Once the modification of the road’s route was presented, all the facilities are recalculated to adapt them to the new route. Mainly, it is the lighting which is affected, since the number of exits and entries does not go down, and the length of the longest tunnel increases to approximately 2,500 m. In addition, adaptation is made to new regulations coming into force for ENERGY EFFICIENCY.
- With all of this, the total number of projectors installed in the inside of the tunnel goes down from 3,166 units to 2,148 units, changing from 1,016 kW to 752.2 kW of inside lighting installed in tunnels.
- Once various design criteria have been modified for the installation of ventilation and lighting, a total power supply is reached of 1,800 kW to be contracted, with Medium Tension tariffs with a maxi-meter. Thus a serious initial problems is solved, due to the lack of infrastructure on the part of the local electricity supply company which hindered the supply of the power initially required in the original project.
- Thus, during the drawing up of the project, the installations for the new route are reviewed, recalculated and adapted. At the same time as updating to the new regulations and technologies in force.
Services Affected
- Multiple diversions of water networks were foreseen to be affected by the new route, both for irrigation, supply for various drainage collectors, in the setting of the two treatment centres adjacent to the work (unfiltered water, treated water and outlets).
- Various diversions of medium tension lines affected were designed, amongst which of particular note is the overhead 20 KV line which supplies the centre of Taurito and the overhead 20 KV line which supplies the Pueblo de Mogán. In addition the main 20 KV lines linking the Arguineguín Substation and Mogán are diverted. In addition the diversions of the low tensions lines affected were undertaken.
- Finally, various diversions of telephony lines were performed.
Other modifications: other lesser modifications have been undertaken, among which to be stressed are:
- Unification of the traffic categories (T1 for the trunk road and T2 for the junctions).
- Homogenisation of the section of road surface along the trunk road to 132 and in all the junctions to 232.
- Finally it is to be stressed that the additional net budget for the Modified Project is ZERO EUROS AND ZERO CENTS (€ 0.00).
Types of service provided:
- Drafting project designs
- Road Works
- Tunnel Works
- Viaduct Works
- Drainage Works
- Electrical Installation Work (LT and HT)
- Public Lighting Works
- Installations in Tunnels Works
- Fire Prevention System Works
- Landscape and Gardening Treatment Works
- Replacement of Overhead and Underground Electrical Network in High Tension