|A view of the Russky Bridge, which has a 1,104-meter-long central span.|
Advanced GNSS equipment aids construction of the world's largest cable-stayed bridge.
It’s a structure designed to impress. Stretching 1885.53 meters (1.17 miles) from the Russian port city of Vladivostok to Russky Island, the Russky Bridge boasts a 1,104-meter-long central span (3,622 feet), making it the largest cable-stayed bridge in the world. It also features the world’s tallest pylons at more than 324 meters high (1,063 feet), and the longest stay cables. Four lanes in each direction are capable of carrying 50,000 cars per day. Estimated to cost more than $1 billion, this modern engineering marvel was constructed in a record-breaking 43 months in preparation for the 2012 Asia-Pacific Economic Corporation (APEC) summit, which was held on Russky Island in September. The Russky Bridge is seen by many as Russia’s gateway to markets in the Asia-Pacific region.
Construction of the bridge was managed by Mostovik, one of the largest engineering and construction companies in Russia. Meeting the tight timeframe and stringent quality standards required careful coordination among designers, engineers and builders, in addition to skilled project management and good communication. Accurate surveys with advanced GNSS equipment were essential to the successful completion of the project.
|Wind-resistant poles kept the Javad receivers steady during the bridge survey work.|
One of the biggest challenges facing the project team was the weather. This region of the world is characterized by very difficult climatic conditions, including temperatures ranging from -31oC to 37oC (-24oF to 99oF), high-speed winds that can reach up to 36 meters per second (81 mph) and storm surges up to 6 meters (20 feet) high. In the winter, ice up to 70 centimeters (28 inches) thick forms in the bay. Strong winds, storms and fog greatly influenced the course of construction, but the completion deadline could not be changed; the team couldn’t afford to wait around for good weather. Crews had to find innovative ways to continue their work.
Geodetic support was required at all times during the bridge construction. Each day, 12 to 15 surveyors from Mostovik were onsite with eight Javad Triumph-1 receivers, four Victor controllers, five high-precision total stations and five levels. It was often necessary to develop new methods quickly to solve geodetic problems; for example, when a trailing bridge unit had to be lifted and set in place in real time with extremely high accuracy, surveyors used six Javad receivers to accomplish the task. To keep the receivers steady in high winds, crews developed wind-resistant auxiliary structures composed of a thick metal pole surrounded by reinforced cages. From these platforms, surveyors were able to unwaveringly perform their work.
|The underside of the wind-resistant platforms that held the Javad GNSS receivers.|
During the installation of the metal panels on the channel span of the bridge, wind loads of up to 1.5 meters caused the panels to oscillate, making it very difficult to achieve the required assembly precision. Through constant measuring with the Javad receivers and post-processing by Javad Justin software, the surveyors were able to define the necessary coordinates for mounting the panels.
The surveyors also used the Javad receivers to monitor the span during the high precision installation of the bridge’s closing unit, where it was necessary to achieve an accuracy of +/- 2 mm.
The project was completed in July 2012 on time and on budget. On Aug. 1, the Russky Bridge opened to traffic--a work of engineering art and the hallmark of Vladivostok. “The bridge has a beautiful architectural structure that embodies the genius of engineering and creativity of our professionals,” said Russian Prime Minister Dmitry Medvedev during the opening ceremony.
According to Mostovik, use of the right equipment was key to successfully completing the project. The company is applying the experience gained from this project to push the technology envelope on other construction projects that require precision monitoring of geodetic points.