Warsaw, Poland is both a major international tourist destination and a major economic hub in central Europe. Located in east-central Poland, the greater Warsaw metropolitan area has a population of more than 2.6 million residents and is one of the largest cities in the European Union.
To help alleviate traffic congestion in the heart of the city, work is currently underway on the construction of S-2 express road, which is a part of Poland's southern Warsaw bypass. The S-2 express road is designed to relieve the central part of the city from heavy traffic, facilitate access to the airport, and provide links to external road networks, including the A2 motorway. The contractor for the S-2 project is a consortium led by Bilfinger Berger Construction SA, a large and well-established Polish construction company that specializes in transportation construction projects including the repair and construction of road infrastructure.
The Trimble 3D PCS900 on southern Warsaw bypass construction. The paver obtains information on current position with a robotic total station located on site.
Bilfinger Berger Construction SA relies on Trimble 3D Machine Control Systems to improve accuracy and productivity on job sites throughout the country, and the S-2 expressway is no exception. One critical part of the S-2 construction project is an 11 km-long section connecting "Konotopa" node, located near the western entrance of the A2 motorway to Warsaw, with the "Airport" node. During work with an asphalt paver the contractor decided to use the Trimble PCS900 Paving Control System, a precise 3D system that improves paving productivity and the ride ability of road surfaces by directly referencing off the road design.
"Compared to the conventional method of laying material, working with a 3D system is much faster," said Emil Gołaszewski, the engineer supervising construction works at Bilfinger Berger Construction SA. "From the beginning, we have gained extra time through eliminating the need for manual and time-consuming string-line assembly."
The Trimble 3D PCS900 System is a fully automatic hydraulic machine control solution that provides control of the height and cross slope of the screed. The PCS900 consists of a Trimble SPS930 Universal Total Station, an MT900 active target, and a CB460 display running the PCS900 on-board software.
Constant controlling of the finished surface to match the given asphalt thickness specification.
The machine pulls the information about current position from a robotic total station that is located on the site. With Trimble's patented active prism technology, the total station continuously measures the position with a frequency of 20 times per second. This allows controlling the screed with a precision of three to six millimeters.
Operation of the system is based on a 3D terrain model prepared in the software Trimble Business Center - Heavy Construction Edition. Trimble Business Center - HCE is a software package designed specifically to streamline site positioning and grade control workflows. Using Trimble Business Center - HCE, Bilfinger can import, review, and analyze graphical design information. Field crews can then assign, manage, and track that information through the construction project. Trimble Business Center - HCE emphasizes efficient management of a single job site and the crews operating on that site at any time.
Active machine prism MT900 on the mast. Trimble's patented technology of active prism makes it easy for the SPS930 Total Station to remain locked to the on-machine target.
Trimble Business Center - HCE handles field measurement, CAD, and design information, and provides specific workflows to manage information for a construction project. Plan, profile, cross section, spreadsheet, and 3D views are all dynamically linked, so edits in one view are automatically reflected in all other views and any associated surface models and contours.
The 3D design data, which was prepared in Business Center- HCE, runs on the Trimble CB460, a machine 3D control box equipped with an extra-large graphical display. With the CB460 a single operator can simultaneously control and monitor the left and right side of the screed for the measured value and the target cross slope and design elevation.
To maintain continuity of laying the material and ensure a smooth finished surface, the work is carried out using three Universal Total stations. Two instruments alternately control the operation of the machine (their spacing within 150 meters provide the highest accuracy), and the third total station is used for ongoing monitoring of the achieved results compared to the project.
The PCS900 can control screed with an accuracy of 3-6 mm, which is ideal for projects such as airports, large commercial areas, roads or highways.
The Trimble Universal Total Stations are unique because of the Trimble active tracking technology, which guarantees lock to the on-machine target, ignoring passing vehicles, strobes, and other reflective objects. This ensures superior tracking for all site measurement tasks and millimeter control of the screed.
"With 3D technology and the proper configuration of the system, we obtained increased smoothness of the road and an accuracy satisfying the required technical specifications," said Gołaszewski.
Distribution and installation of Trimble machine control systems was provided by Trimtech Ltd., the exclusive dealer of Trimble technology solutions for heavy civil contractors in Poland. Trimtech Ltd. provides the tools and support to ensure the integration of data for the planning, designing and positioning of construction, machine control and asset management throughout the lifecycle of construction projects.