The world’s largest cable-stayed bridge across the Eastern Bosphorus Strait in Vladivostok is equipped with an automated precision monitoring system, which allows a continuous holistic health monitoring of the giant installation to be conducted using simultaneously two satellite-based global positioning systems, GLONASS and GPS.
“The Bridge to Russky Island is located in a very tough climate zone, which is defined by the seashore and gusty storm winds. The cable-stayed giant calls for special attention because of the unique engineering features as well as safety and operational reliability requirements. When the project was built, a holistic automated monitoring system which integrates more than 500 state-of-the-art sensors was designed and put in place. The system allows for real-time monitoring of bridge health parameters and also the weather conditions and the wind loads”,– says Gennady Shkuropatov, Director of the Special Branch of OJSC USK MOST in Vladivostok.
“Using special devices installed on the bridge, which receive satellite system signals, we can also conduct the precision monitoring of 3-D positions of all elements of the giant installation that connects the mainland to Russky Island. A huge display board in the Control Center that monitors the bridge over the Eastern Bosphorus Strait is also called a video wall.”
Numerous displays and monitors that occupy the entire display in real time show all incoming data such as visibility, wind velocity, roadway temperature, traction coefficient, water film thickness, lane traffic intensity, traffic flow density, and many others.
“The totality of the data determines the actions taken by the 24-hour control team. More specifically, safe speed limits are set up for traffic via the bridge, based on the acquired data”,– says Artem Efremenko, Chief Engineer of the Automated Control System.
“All drivers can get the necessary information from the billboards that are installed at the bridge entry on both sides – on the Nazimov Peninsula end and on the Russky Island end.”
After the giant cable-stayed bridge has been put in service, the innovative monitoring system integrated a variety of sensor types, including GLONASS /GPS receivers, tachymeters, inclinometers, seismometers, which provide the precise position monitoring and monitor health monitoring of the structural members. Color coding is used to show the bridge health. Precision sensors are mounted on the pylons, stay cables, reinforced concrete girders and steel stiffening girders. The green light on the screen means that everything is OK; yellow warns of the approaching alarm level in the preset range; red is the alarm level. However, only green light has been there all the time since the moment the bridge was put in service.
“During the period of observation, winds of up to 21-25 meters per second and even stronger occurred, which is the speed that calls for putting in place restrictions or even close down the traffic for the sake of safety of the drivers and vehicles”,– says Sergey Safronov, Engineer of the Automated Control System.
“However, even with strong winds, the structures have never been close to the warning level. Therefore, the period of operation confirmed to the full extent that the design, process, and engineering concepts that were adopted when the unique bridge to Russky Island was designed and built were correct.”
“The bridge to Russky Island is operated in the normal mode, and all the fears and conjectures that existed during the period of construction, especially at the initial stages have been forgotten”,– continues Gennady Shkuropatov.
“The monitoring data confirms the correctness of the analyses results dealing with both predicted stresses in the bridge structures and with installation of the girder and stay-cable system which can withstand the hurricane-level winds in the Eastern Bosphorus Strait.”