The Monitor And Analysis Of Longitudinal Forces From The CWR In Non-ballasted Track On Long Span Bridge For High Speed Railway

With the safe operation of Beijing-Tianjin intercity railway, Nanchang-Jiujiang intercityrailway, Beijing-Shanghai high-speed rail, by2012, the mileage of the high speed rail inChina will exceed13,000km, the number of the railway will reach1.6million km in2020.High-speed rail is gradually rewriting the Chinese mode of production and ways of life.Therefore, people pay more attention to the safe and comfort of the high speed railways. Asthe complex structure of the high speed railway on the long span bridge, it not only combinesthe technical points of cross-CWR, non-ballasted track, long span bridges and rail station, butalso derives a series of technical difficulties, such as the adapt of CWR and long span bridge、the adapt of welded turnout and rail station、 long span bridges and rail stations innon-ballasted track impact the CWR、 the check and evaluate of the cross-CWR、the detectand monitor of the CWR. Therefore, this paper combines of a high speed railway in China tocarry out the related research of high speed railway in long span bridge、rail station and CWRwith non-ballasted track, it guides our high speed railway construction、it solutes the problemsof the construct and operate of high speed railway, so it has important engineeringsignificance. The main research contents and conclusions in this paper are as follows.The main research contents in this paper are as follows:（1）By theoretical and experimental analysis, the main indexes of the detect andmonitor of the CWR on the long bridge have got. It includes the temperature of the rail、therail plate temperatures at different depths、the longitudinal forces of the rail、the relativevertical displacement between the rail and rail plate、the relative displacement between the railplate and girder body、beam end displacement.（2）Aim to the temperature force of CWR and locked rail temperature、the temperaturechange in girder body、rail displacement、displacement of girder and other major items,multiple experiments indoor and outdoor had been done to study the sensitivity of theproposed monitoring system、scale and errors，and established the technical standards ofmonitoring equipment.（3）Aim to the features of the detect and monitor of the high speed railway, and thespecific features of the CWR on the long bridge in construction、commissioning and operation.Using GPS global positioning technology and wireless network transmission technology tomonitor the CWR automatically. （4）Select the continuous girder of the large bridge as research object, detect andmonitor the longitudinal displacement of girder body、the angles of rotation at the support ofbeams、the longitudinal displacement of rail、thermal stress of rail、track geometry of CWR.The long-term monitoring places in the long bridge are determined.（5）Establishment of the long-term monitoring places in the long bridge, regularobservation of the temperature of the long rail、the rail plate temperatures at different depths、the longitudinal forces of the rail、the relative vertical displacement between the rail and railplate、 the relative displacement between the rail plate and girder body, in order to get theforce of the rail and deformation variation with time.The main conclusions are as follows:（1）The test methods of additional contractility and longitudinal force are got byanalyzing, is proved feasible.（2）By analyzing, the monitor system of the CWR in non-ballasted track on long spanbridge for high speed railway are established, it can be monitor better by the indications fromthe system.（3）The track plate temperature, rail temperature and the temperature trend line, andthere is good correlation. Orbital plate temperature range is much smaller than the changes inrail temperature, and there is a certain lag. Orbital plate temperature decreases with increasingdepth.（4）The longitudinal forces of the rail in the No.2pier is maximum, the longitudinalforce can be up to605.8KN. Therefore, the effect measure of reduce the longitudinal force ofrail is to shorten the span of the bridge. the greater the span of the bridge, the greater thelongitudinal forces.（5）The relative displacement between the rail and rail plate is very small, thetemperature change range of the rail at20℃, the maximum displacement of the rail board isless than0.4mm, it shows that the stability of the track is very good.（6）The relative displacement between the rail plate and the girder body can be reach10mm, it shows that the sliding layer has great effect.