Limitless LLC, an arm of Dubai World, is an integrated real estate development firm based in Dubai. One of its projects, the Arabian Canal, is the largest and most complex civil engineering project ever conducted in the Middle East. A 75 km waterway, surrounded by public space for leisure, community events and all types of commercial, residential and entertainment real estate, will be built.  Limitless is responsible for the managing the design and construction of the entire canal, and developing 10,000 hectares of real estate through which the canal will flow.

The Challenge

The enormous set of challenges associated with such a massive construction project is made all the more difficult with the requirement that it be completed within 3 to 5 years. In order to meet this timeline, a volume of at least 1.5 Million cubic meters of earth needs to move each day, equivalent to scooping out an area of 5 km by 300 m with 1 m depth.

The amount of earth moved each day must be accurately measured to meet three critical requirements: progress against plan, as built against plan, and invoicing. Progress reports on cubic meters of earth moved per day allow the project managers to accurately track the project and quickly identify any slowdowns that need addressing. An accurate 3D map of the dig provides a fast and efficient means of continuously monitoring the dig against the plans and make adjustments as necessary. The volume of earth moved is used to validate the invoices submitted by the subcontractors working on the project.

The Solution

For smaller construction projects, earth works monitoring is often carried out using traditional survey equipment such as total stations or GPS, or more recently 3D static scanners that produce highly accurate point clouds from which geometric measurements can be made.  However for such a large area, and given the constraint that measurements could only be made between shift changes (approx 0.5 hour every 12 hours), it was quickly determined that using traditional static methods would require a large number of crews and equipment at a great expense. Even more troublesome was the risk that the area might not be able to be surveyed within the time constraint. Based upon this a decision was made to use mobile mapping technology instead of static surveying techniques. Mobile mapping reduces both the cost and the schedule risk by increasing the efficiency of the collection process.

Two mobile mapping platforms were chosen: a helicopter based Applanix DSS with LMS-Q240 LIDAR option, and a land vehicle based Applanix LandMark. The Applanix DSS produces directly georeferenced high-resolution orthomosaic color image maps and high-accuracy 3D terrain measurements in the form of laser point clouds and digital surface models. Similarly the Applanix LandMark produces georeferenced oblique video imagery and high density laser point clouds. The land and airborne data sets are combined to produce a high-accuracy, high-density 3D terrain model of the dig with build in redundancy.   Work has now begun.

Image 1: Digital Surface Model produced in Modeler QT

Image 2: Digital Surface Model Dubai Canal