Application case of hydraulic tensioner in bridge cable installation

In modern large-scale bridge construction, the installation accuracy and quality of the cable play a vital role in the structural safety and service life of the bridge. As an advanced tension control device, the hydraulic tensioner has been widely used in bridge cable installation projects. The following is a detailed introduction to the application of hydraulic tensioner by taking a cross-sea bridge cable installation project as an example.

Project background

The cross-sea bridge is a transportation hub connecting two important cities with a total length of about 15 kilometers. The main bridge adopts a cable-stayed bridge structure with a large number of cables and extremely high tension accuracy requirements for the cables. The traditional cable tensioning method is difficult to meet such high standards, so it is decided to introduce a hydraulic tensioner to ensure the quality and accuracy of cable installation.

Selection and configuration of hydraulic tensioner

In view of the characteristics and needs of this project, a hydraulic tensioner with advanced technical features such as high precision, large tonnage and intelligent control was selected. The tensioner is mainly composed of a host, a control system, a sensor and other parts. The main machine is made of high-strength alloy material, with good stability and reliability, and can withstand tension up to thousands of tons. The control system adopts advanced PLC (programmable logic controller) and human-machine interface (HMI) technology to realize real-time monitoring and control of tension. Operators can intuitively view tension data and equipment operation status through the HMI interface and perform remote operations as needed. The sensor uses a high-precision strain-type tension sensor, which can accurately measure the tension of the steel cable with a measurement accuracy of ±0.5%.

Application during installation

Hydraulic tension machines play an important role in the installation of bridge cables. First, during the erection stage of the steel cable, the hydraulic tension machine is used to accurately control the initial tension of the steel cable to ensure the stability and straightness of the steel cable during the erection process. The operator sets the initial tension value in the control system according to the design requirements, and the hydraulic tension machine automatically adjusts the stroke of the oil cylinder to make the steel cable reach the set tension value. At the same time, the tension changes of the steel cable are monitored in real time through the sensor, and timely feedback is given to the control system to ensure the accuracy of the initial tension.

During the tensioning stage of the steel cable, the hydraulic tension machine plays a key role. The steel cable is tensioned by graded tensioning, and different tensioning levels and tension values ​​are set according to the design requirements. The hydraulic tensioner gradually increases the oil pressure of the cylinder according to the instructions of the control system to make the steel cable reach the corresponding tension value. During the tensioning process, the sensor monitors the tension of the steel cable in real time. When the tension reaches the set value, the control system automatically stops the action of the cylinder to ensure the accuracy and safety of the tensioning process.

In order to ensure the uniformity of the tension of the steel cable, multiple hydraulic tensioners are also used to work together during the entire installation process. The control system coordinates and synchronously controls the tension of multiple tensioners in real time to keep the tension of each steel cable consistent, effectively avoiding the deformation of the steel cable and uneven force on the bridge structure caused by uneven tension.

Application Effects and Advantages

By applying the hydraulic tensioner in the steel cable installation project of the cross-sea bridge, significant effects and obvious advantages have been achieved.

​​High-precision tension control​​: The application of the hydraulic tensioner greatly improves the tension control accuracy of the steel cable, meets the high standards required by the design, and effectively ensures the structural safety and service life of the bridge.
​​Improve installation efficiency​​: Automated operation and precise control make the cable tensioning process faster and more efficient, reduce the errors and labor intensity of manual operation, greatly improve the efficiency of cable installation, and shorten the construction period.
​​Ensure construction safety​​: The intelligent control system and real-time monitoring function of the sensor of the hydraulic tension machine can detect and handle abnormal situations in time, avoid safety accidents caused by excessive or insufficient tension, and ensure the life safety of construction personnel and the normal operation of equipment.
Conclusion