In bridge health monitoring, inclinometers are usually arranged on the bridge deck, tower, pier and suspension cable to measure the deformation of the bridge under load and evaluate the integrity and stability of the bridge structure. Among them, the main purpose of monitoring the bridge deck deformation is to judge the important technical parameters such as the stiffness and structural bearing capacity of the bridge in the vertical direction, which are the key reference indicators in the process of bridge identification, reconstruction and new bridge acceptance. The bridge tower is another place that needs to be measured by the inclination sensor. To a certain extent, the inclination value of the bridge tower reflects whether the integrity and stability of the bridge structure are affected, and whether it will endanger the safety of the bridge.

The monitoring items of the super large bridge can be divided into two parts: load source and structural static and dynamic response. The general principles for determination are as follows:

1. selection principle of monitoring items

① According to the importance of various structural members of the bridge in structural safety and the vulnerability of members;

② According to the geographical and climatic environment characteristics of the bridge, the factors affecting the stress of the bridge structure are determined;

③ Starting from the needs of structural state assessment and operation maintenance management, technical preparations should be made for future state identification and structural safety evaluation;

④ The special structure of the bridge should be monitored;

⑤ According to the characteristics of the bridge, capital investment and economy, real-time monitoring and regular monitoring are combined to realize bridge monitoring and early warning.

2. the monitoring project is based on the bidding documents and the above principles, and in combination with the operating environment characteristics, structural stress characteristics and structural characteristics of the super large bridge site, the monitoring project is divided into environmental parameters and load sources, structural response monitoring, structural durability monitoring and other monitoring:

(1) Load source monitoring items:

① Wind load (including wind speed and direction); 

(2) Structural response monitoring:

① Main beam displacement monitoring; ② Stress and strain monitoring; ③ Cable tension monitoring of stay cables; ④ Tower tilt monitoring; According to the bidding documents, the monitoring items and the scale of measuring points of the automatic sensing test subsystem of the monitoring system of Dachong Yongjiang super large bridge are shown in the table below.

The principle of product selection is: 1 Select the current international advanced technical equipment to ensure good accuracy, stability, durability and scalability of the system; two Select products with good versatility and easy purchase in the market to ensure the maintainability and replaceability of the system; three Select products with high performance price ratio to ensure the best operation of the system at the lowest cost and realize bridge monitoring and early warning; four The system has reached the international advanced level.

 The BWS5500 series ultra-high precision inclinometer produced by BWSENSING is selected as the high-precision inclinometer product, and the sampling frequency is 1Hz.

Project overview

Jiangyin Yangtze River Bridge is a river crossing channel connecting Jingjiang City and Jiangyin City in Jiangsu Province, China. It is a key construction project during the Ninth Five Year Plan period in China. It is the "throat" project of Tongjiang Sanya national highway trunk line and Beijing Shanghai national highway trunk line in the main skeleton of China's "two vertical and two horizontal" highway. North micro sensor and sujiaoke have established a complete set of effective safety monitoring measures for bridge monitoring to ensure bridge safety.

Solution

● product: real time feedback of bridge data through inclination sensor equipment;

● data: timely discover and warn potential safety hazards in combination with on-site video images, meteorological data, etc;

● cloud platform: collect data through products, integrate big data platform, and provide security analysis data and early warning.

Customer value

● reduce the workload of manual patrol inspection and ensure personnel safety;

● standardized personnel and equipment management, informatization and real-time management;

● early warning to avoid safety accidents caused by hidden dangers.