Light Rail Transit

Usually, cities develop light rail transit (LRT) systems as a means of addressing existing traffic problems. This project, however, was completely atypical: it called for the development of an LRT in a city that existed only on paper. The initial phase consisted in designing and building seven underground stations, a viaduct over the motorway that connects Doha to the northern part of the country, and preliminary works that included a depot and maintenance workshop for the LRT system. The second phase consisted in the construction of 25 stations and a depot, architectural and electromechanical lots, integrated project management, track-laying, power supply, telecommunications and control, and the delivery by our partner Alstom of 35 railcars equipped with catenary-free technology. The Yellow Line The yellow line was delivered in 2019 and the green, red and purple lines in 2020.

BACKGROUND

Since 2005, the government of Qatar has, through the Qatari Diar investment fund, been undertaking the development of a new urban centre in the desert: the city of Lusail. This city is ready to welcome 200,000 residents and 400,000 visitors a day in an area measuring 21 square kilometres consisting of business districts, residential zones, schools, leisure services, and two 18-hole golf courses.
This LRT, built in a city that didn’t exist before, is one of the most modern public transport systems in the world; in addition, it used catenary-free technology (no aerial cables) in an effort to preserve the city’s visual appeal. This project reflects a contemporary and effective vision for urban development as it focuses on building transport infrastructure, especially a public transport system, first.
This LRT is a turnkey project delivery designed to serve the whole community. This design-build contract is carried out by QDVC in consortium with Alstom.

TECHNICAL OVERVIEW

Geophysical and seismic surveys were conducted along the projected LRT route in its entirety. The surveys revealed that the rock layering (stratigraphy) in the project site is comparable to the general geology of Qatar. The surveys enabled us to distinguish a set of superficial layers measuring two to nine metres in thickness, depending on location. Also visible is a limestone formation that is characteristic of the geology of Qatar.
To prevent local instability in the altered limestone, a layer of sprayed concrete eight to ten centimetres thick reinforced with a metal grid was implemented. Deep in the ground, the rock is more stable, making the use of nailing and sprayed concrete less necessary generally. Wherever there were thicker layers of soft soil, the choice of support solutions depended the location’s specific properties.
However, it was necessary to backfill and stabilise certain locations to allow a mobile crane to be placed at the trench end in order to conduct the civil engineering works associated with the tunnelling operations. In such cases, a mixed support solution was used that included geotextile-reinforced backfill in the soil and rock-nailing. Finally, for excavation operations in proximity to existing buildings, the solution was to build a 10-foot-high soldier-pile wall for ground support. The wall is anchored on the surface of the bedrock. Once the excavation reaches the foot of the soldier-pile wall, a two to three-metre berm is retained, and excavation continues in the rock at the foot of the soldier-pile wall with the use of nailing and sprayed concrete.

The LRT consists of 4 lines covering 30 kilometres, including seven underground stations and 25 elevated stations. The new city of Lusail covers 21 square kilometres on the sea front and eventually be home to a population of 200,000. It also welcomes some 400,000 workers and visitors on a daily basis.

IMPACT

Sustainable development was a major criterion in designing this new city. Accordingly, one of the requirements for the development of its transit network was to ensure minimal greenhouse gas emissions. This infrastructure will be connected to the Doha metro in efforts to facilitate travel in Qatar’s largest urban agglomeration. On this project, investors in Qatar adopted an original urban-development strategy: they structured the development of a new city by starting with its public transit infrastructure.
Low-floor trams ensure easy access for passengers with reduced mobility. Qatar Railways Company has opted for high-end comfort for passengers as well as communications systems to keep passengers informed and security systems onboard and at stations to keep them safe.
In seven years, VINCI Construction Grands Projets has, through QDVC, became a major construction player in Qatar. After delivering the country’s largest wastewater-pumping station in northern Doha, the Company is active on multiple projects, including construction of a new motorway on the outskirts of Doha (the New Orbital Highway), the Doha metro (the south works package for the Red Line), and the underground car park and garden-landscaping at the Sheraton Hotel in the centre of the West Bay business district (Sheraton Park Project).

Project participants

Client
Qatar Rail

Project management
Qatar Rail

Key figures

Implementation dates
February 2009 to June 2020

Number of stations
32

Number of lines
4

Distance
30 km