Research On Grating Joint Meter Applied In The Uplift Deformation Monitoring Of Crts Ⅱ Ballastless Track Slab

The stability and comfort is the key to the normal operation of high speed railway.Due to the high requirement of smoothless of the track,a small deformation may lead to serious consequences for the running train on the strack.Therefore,it is necessary to carry out the continuous deformation monitoring about the structure under track for the operation of high speed railway.China is a vast country,and its north and south regions appear large differences in the climate degree.It makes the temperature stress act upon CRTSⅡballastless track slab very complicatedly,and results in a variety of diseases,such as expansion deformation and upward deformation of ballastless track slab.At present,the detection of the upward deformation of ballastless track slab mainly depends on the field inspection and leveling measurement.In this method,the efficiency of detection is very poor,and it is difficult to complete all inspection in the limited time available.So it is necessary to study the automatic monitoring of expansion deformation and upward deformation of ballastless track slab.According to the above content,the following work has been carried out from the choice of automatic monitoring method,the implementation of monitoring scheme,the verification of technology method and so on:(1)In aspects of the automatic monitoring of upward deformation of ballastless track slab,the properties of the mechanical grating joint meter,distributed grating,and the tilt sensor were analyzed and compared from monitoring type,temperature effect,data quality,economic efficiency and safety.(2)On the basis of clearly adopting the mechanical grating joint meter to monitor upward deformation of ballastless track slab,the new mechanical grating joint meter and supporting facilities are designed according to the characteristics of thermal deformation of ballastless track slab and disadvantage of the conventional grating sensor.(3)Considering the particularity of high-speed railway monitoring conditions,the safety of measuring equipment is verified.Also considering the monitoring efficiency and economic benefits and other factors,the principles of installation of monitoring instruments are put forward.(4)Under different environmental conditions,the test of mechanical grating joint meter against high temperature,vibration and water pouring is done.According to the experimental data,the deformation characteristics of track slab subjected to temperature are preliminarily analyzed.The research shows that the mechanical grating joint meter performs stably under the external interferences,such as the high temperature,vibrations and water pouring.The reliability and accuracy of the mechanical grating joint meter is very perfect and meets the requirements of track slab monitoring.The application of the improved grating joint meter and the principles of the installment,which is described as the combination of the traditional mechanical grating joint meter with the new one and the principle of combining differentiation with dynamic adjustment,can improve efficiency and reduce the costs.The research has a certain reference value for the automatic monitoring of upward deformation of ballastless track slab and the analysis of ballastless track slab deformation law in the future.