Development And Application On The Inspection Trolleys Of The Steel-concrete Composite Girder Of The Hongkong-Zhuhai-Macao Bridge

Steel structure corrosion,welded seam fatigue and bolt loosening are common defects for steel structure bridges.Therefore,inspection trolleys are necessary for the steel bridge maintenance to ensure the durability,safety and service life.In order to ensure the safety and normal operation of the bridge,the effective means of monitoring,prediction and control of the steel beam daily operation and structural damage and corrosion defects in the later period can be quickly realized without closing traffic,and provide an effective guarantee for prediction and control.Inspection of the vehicle in the future detection,maintenance and repair needs to play a vital role.Based on the survey of bridge inspection trolleys both at home and abroad,giving the maintenance requirement of steel/concrete composite girder in Hong-Kong Zhuhai Macao Bridge(HZMB),this paper summarizes the shortcomings of current bridge inspection trolleys and designs a new vehicle and its track system for the HZMB project under bridge inspection.This paper describes the under bridge inspection trolley from the truss system,the electric control system,the track system,the driving and braking system,as well as the on-site acceptance and usage situation.The fully automatic under bridge inspection trolley can provide safe environment for on-site workers.And helps to comprehensively check and maintain the bottom plate,web plate and flange plate of the composite girders.Working with the track system,the trolleys are capable of detouring piers and passing expansion joints and running on rails with variable spacing.According to the principle of triple inspection vehicle,the number of inspection vehicles is greatly reduced,which not only achieves aesthetic effect,but also improves economic efficiency and maintenance efficiency.In the nearly 1 years' commissioning in HZMB project,the under bridge inspection trolley fully realize the preset function.This study has significant reference value for the design and application of bridge inspection trolleys for similar projects at home and abroad.