2. PROJECT DESCRIPTION

Transcription

1 4 2. PROJECT DESCRIPTION 2.1. PROJECT LOCATION AND DESIGN The proposed Project is located in the southwest of the SRR International Airport at Plaine Magnien, District of Grand Port - Savanne, Figure 2-1. The proposed route is 4.3 km long and will connect the airport to the M1 motorway through a southern bypass of Plaine Magnien. In total 3 roundabouts are proposed along the route: to the north and southwest of the new Holiday Inn Hotel; and to the south of Plaine Magnien (B8, La Barraque Road ). The junction with the M1 will be in the SE of Mare d Albert where a new interchange will be provided. The design speed selected for the New Access Road is 100 km/h, and the design life is 20 years. A dual carriageway (2 x 2 lanes of 3.65m each) with a central reserve of 5 m is proposed. The shoulders will be 3.5 m wide (2m paved and 1.5 unpaved). The total cross section will thus be 26.6m. A typical cross section of the Project road is provided in Figure 2-2. Further, to be able to accommodate any future airport / regional extension / development, it is considered desirable to provide for additional lanes resulting in the carriageway being ultimately 2x3 lanes. The overall road x-section will then be 33.9, say, 34m. However, road reserves and need for landscaping will entail the acquisition of a 50m wide corridor.

2 5 Figure 2-1: Project location (A1 size map follows)

3 6 Figure 2-2: New Airport Access Road: typical cross section

4 7 In the initial 0.6 km section of the Project (between the airport and roundabout near the Holiday Inn Hotel) a single carriageway (2x1 lanes) already exists (Figure 2-3), connecting the airport and Holiday Inn Airport Hotel to the Mon Désert Road (B85). In this section the proposed design is to widen the existing road on the right side (in the airport Hotel direction). The following 3.7 km of the Project route (i.e. the section from the roundabout at Holiday Inn Hotel to the M1 Motorway) will be an entirely new road, which mainly passes through sugarcane plantations. In developing the route, existing parallel cane tracks will, as far as possible, be maintained so as not to hamper access to the surrounding land and to preserve access that can be used for material transport during construction. Figure 2-3: Existing single carriageway road along the first 0.6 km of the Project road. Left: view from the airport to the south; Right: view from first roundabout towards the north 2.2. STORMWATER DRAINAGE The new airport access road will be a classified road and must be designed such as to fulfill its functions at all times. The proposed drainage design is initially based on relevant criteria as established by the WRU and Intensity-Duration-Frequency (IDF) curves provided by the Mauritius Meteorological Services (MMS). The existing IDF curves, however, do not incorporate more recently observed trends of climate change and related phenomena such as the noted increased frequency of say, 25-year rainfall. In response to these observations, a 25-yr return period was adopted for the design of drainage structures. Various types of drains will be provided. Lined open channels will be provided locally to direct the storm flow to cross drainage structures and from there to absorption pits. From there the runoff will gradually percolate into the permeable underground. In total, 7 absorption pits are proposed which typically measure 5m x 10m and 3 m deep. The typical section of an absorption pit as proposed under the Project is shown in Figure 2-4. The overall stormwater drainage layout is illustrated in Figure 2-5. Figure 2-6 provides typical sections of the various drains.

5 8 Figure 2-4: Absorption pit details, typical layout as proposed under the Project

6 9 Figure 2-5: Stormwater drainage layout (A1 size follows))

7 10 Figure 2-6 : Typical Sections of Drains

8 ROAD FURNITURE In line with usual standards for such roads, the Project will have, inter alia, usual road markings, street lighting throughout the route and guardrails along the central verge. LED lightning will be provided throughout the Project route in the central reserve, as shown in Figure PROJECT CONSTRUCTION According to the project proponent, construction contracts will be awarded through an open international bidding process. Given the size and location of the project it is assumed that there will be no on-site accommodation of workers. Construction will comprise, inter alia, the following main activities: Preparatory works Preparation of the contractor s yard; Land clearing; removal and temporary storage of topsoil; Earthworks and temporary storage of soil; Scarifying of existing roads and other sealed surfaces; Rerouting of services; Temporary storage of rubble / spoils. Construction Road construction: subgrade preparation and embankment construction; Pavement construction; Construction of roadside drains; Construction of new service utilities networks; Road furniture, electrical installations; Landscaping; Decommissioning of contractor s yard and site clean-up. Construction Equipment / Plant Equipment used for a road construction project of the present size and type would usually involve the following: Tractors with dozer and / or ripper Scraper Excavator Power grader Rollers Concrete mixer Poker vibrator Bitumen sprayer Asphalt paver Compressor Dumper Lorry with service platform Water distributor (bowser)

9 Agricultural tractor and trailer Cutting equipment Pump and motor Pickup trucks Welding equipment Stone crushing plant (not necessarily on site 7 ) Asphalt plant (not necessarily on site). 12 Workforce The estimated number of people to be employed under the Project is not known at this point in time. At the tendering stage however, Contractors will be requested to indicate their manpower requirement needed to complete the works within the prescribed time schedule LANDSCAPING The New Access Road will be the gateway to Mauritius for any visitor from abroad and as such has an important function in representing Mauritius as a top destination for high end tourism in the region and in supporting the Government s intention to develop Mauritius as an international hub in the Indian Ocean. Therefore a landscaping concept will be prepared separately as part of the detailed design to provide for appealing plantations of high aesthetic value. Space for plantations is available throughout the central reserve and the embankments as well as in the roundabouts LAND REQUIREMENTS AND OWNERSHIP The overall road x-section for a carriageway of 2x3 lanes compute to 34m as mentioned in section 2.1 above. Taking on board land required for, inter alia, landscaping, a land corridor of total width 50m will be acquired. The total land requirements work out to 21.5 ha belonging to Omnicane Ltd. Omnicane Ltd has agreed to vest this land into AML-RDA for construction of the said road. ANNEX 1 provides a copy of the letter of intent from Omnicane Ltd, including a figure providing coordinates of a few points on the proposed road alignment, and ANNEX 1a provides a Notary Certificate confirming that the land to be made available for the construction of the new road belongs to OMNICANE Ltd.. AML will fund all construction costs. Eventually, the road will be a classified road and will be operated and maintained by the RDA PROJECT IMPLEMENTATION According to the project proponent, project completion is scheduled for the second half of 2015 so as to quickly improve road safety and access to and from the airport. 7 Note that a PCU crushing plant is located in the immediate vicinity of the Project site