TTSJ900-general Bridging Machine Used Both Inside And Outside Of Tunnels

With the development of China’s high-speed railway construction, China’s high-speedrailway has been developed into the mountains, such as the Southwest region. High-speedrailway construction in these areas runs into tunnels after over the bridges,which areconnected all the time. It is called wonders in the world. The early separated bridgelaunching and transporting equipmentscan not solve the problem of launching gantrys inzerodistance of tunnelentrance. Manyrestrictions and huge dismantle works arerequiredfor launching gantrys. Even the special carrier can place girders at tunnel entrance，but its effectiveness is much lower than the separatedlaunching gantrys and has bigger fuelconsumption，thus high costs. Therefore a separatedlaunching gantry with high efficiency，lowfuel consumption， which can also place girders at entrances of the tunnels， or eveninside of the tunnels is in a great need.This paper studies the following:Analysis the general situation for launching gantrys from both domestic andinternational，gives introduction to modles and charactors of major existinghigh-speedrailway bridge launching equipments. Through analysis, we propose a separate typelaunching gantry model for working inside of the tunnel, and introduce the technicalfeatures of this model.Analysis the basic structure of the launching gantry used both inside and outside thetunnel，studythe details of the construction methodunder various constructionconditions.The study indicates that this new model has met the construction requirementsof palcingthe girder at tunnel entrance and also inside of the tunnel. Transporting and launching arealso achieved separately with carrying the girder by the transporterto have lower fuelconsumption, fast girder transporting speed， more adaptive in slopes， and can gothrough small curves，etc., which improvesbridge equipment efficencyand reduces the costof girdertransporting.Designcalculationsare made for the main parts of theuniversal launching gantryusedboth inside and outside of tunnels. Theequipmentoperating parameters and various componentmodelselectionsare determined by the calculation， which provide designinsureance for the good operation of the launching gantry.Theoreticalcalculationshave also been made for overturning stability and the mainbeam stiffness and strength of LG inside and outside of the tunnel.Stressanalysis model isalso established with three-dimensional structure under the most unfavorable conditionsfor the main beam of launching gantry. By using ANSYS finite element analysis software，main beam structure of the new launching gantry can be three-dimensional finite elementanalyzed.Throughsimulation calculation, and compare with theoretical analysis,safetymarginof theoretical analysis could be given as well as theaffect to the main beam causedby the temperature changes. Finally, modal analysisfor the main beam will be given toavoid main beam resonance caused by the load factor. By studying all the above keytechnologies and calculationof this model, we can ensure the safe and stable operation ofthis launching gantry.After the equipment put into use, solutions have been made forthe majorissuesoccurred on site. Through the actual implementation of these solutions,theoperational stability of the launchinggantry was improved.The failure rate oflaunchinggantry is reduced as well. Then, the promoted designwas given for further improvement ofthe effectiveness of this model.