Bridge online health monitoring system

1.System Overview

Figure 1.1 Topology diagram of online monitoring system

The system consists of a perception layer, a transmission layer, and an application layer, specifically consisting of a sensor subsystem, a data acquisition subsystem, a data transmission subsystem, a database subsystem, a data processing and control subsystem, a security evaluation and early warning subsystem. Through mutual coordination among various layers, the corresponding functions of the system are achieved.

2.Main monitoring content

Monitoring category		Monitoring content	Monitoring Options
Environment	Temperature and humidity	Environmental temperature and humidity a in the bridge site area	●
		Temperature and humidity inside the main beam	●
		Temperature and humidity inside the main cable	○
		Temperature and humidity inside the anchor chamber b	●
		Temperature and humidity inside the saddle cover	●
		Temperature and humidity inside the tower	○
	Freeze	Bridge deck icing, main cable icing	◎
Role	Vehicle load	Vehicle weight, axle weight, number of axles, and vehicle speed in all lanes	●
		Traffic volume in all lanes	●
		Video images of vehicle spatial distribution in all lanes	◎
	Wind speed and direction	Bridge deck wind speed and direction	●
	Wind speed and direction	Tower top wind speed and direction	●
	Wind presssure	Main beam wind pressure	◎
	Structure temperature	Temperature of concrete or steel structural components	●
	Structure temperature	Temperature of bridge deck pavement layer	○
	Ship collision	Pier acceleration	○
	Ship collision	Video image	○
	Earthquake	Ground acceleration on the bridge bank	◎
		Acceleration at the top of the bearing platform or at the bottom of the bridge pier (Seismic fortification intensity of VII or above)	●
		Acceleration at the top of the bearing platform or at the bottom of the bridge pier (Seismic fortification intensity is VII or below)	○
Structural response	Displacement	Vertical displacement of main beam	●
		Lateral displacement of main beam	●
		Support displacement	●
		Longitudinal displacement of beam end	●
		Tower top deviation	●
		Main cable deviation	○
	Corner	Tower top corner	◎
		Horizontal corner of beam end	●
		Vertical corner at beam end	●
	Strain	Key section strain of the main beam	●
	Strain	Strain of critical section of cable tower	○
	Cable force	Sling force	●
	Cable force	Anchor span cable strand force	●
	Support reaction force	Support reaction force	○
	vibrate	Vertical vibration acceleration of main beam	●
		Lateral vibration acceleration of main beam	●
		Longitudinal vibration acceleration of main beam	○
		Horizontal bidirectional vibration acceleration of tower top	●
		Sling vibration acceleration	●
Structural changes	Foundation erosion	Foundation scouring depth	◎
	Displacement	Anchor displacement	●
	Crack	Cracks in concrete structures	○
	Crack	Steel structure cracks	○
	Corrosion	Chloride ion concentration in pier body and cushion cap concrete	◎
	Corrosion	Depth of chloride ion erosion in pier body and cushion cap concrete	◎
	Broken wire	Broken wire of sling and main cable	○
	Bolt status	Cable clamp screw tightening force, high-strength bolt tightening force, bolt slipping	○
	Cable clamp slip	Cable clamp slip	○
Pour：●Selected monitoring items，○Choosing monitoring items is advisable，◎Is an optional monitoring item。
A only applies to closed box girders. B Only applicable to ground anchored suspension bridge.