Research On Wireless Automatic Monitoring And Early Warning System For Subgrade Settlement Of High Speed Railway

Subgrade settlement appears in many sections along with the construction of large-scale high-speed railway,which has a serious impact on the track smoothness and driving safety.But there is not enough proper means of monitoring for subgrade settlement.In the present,most monitoring methods cost much time and human resources and the monitoring frequency is determined by the time course of “window”.In this paper,the research of calculating subgrade settlement by measuring the horizontal inclined deformation of bed slab(or track plate)is carried out.The research of the monitoring method is carried out according to the working principle of the monitoring instruments.By the use of the field experiments conducted at working point,the proposal monitoring method is analyzed,and warning indicators of settlement,warning level,emergency measures are proposed and corresponding to the new monitoring system.Research achievements of this paper enrich the method of the ballastless track subgrade settlement monitoring.It is meaningful to guarantee the safety operation of high-speed rail train,scientific research and practical application.At the beginning of the paper,the state of the art for monitoring settlement at home and abroad are introduced.Secondly,the mechanism of high-speed railway subgrade settlement and disease occurrence are analyzed and the method of calculating subgrade settlement is introduced.The paper focus on the monitoring system of the subgrade settlement developed by the research group,and the monitoring system includes the working principle of the monitoring system,and the functional structural design of monitoring instruments.The monitoring method corresponding to the developed new monitoring instructions is proposed and includes the installation of the monitoring instruments,the spacing of the installation of the monitoring instruments,and the analysis of the measuring accuracy of the monitoring instruments.At the end of the paper,field experiments are conducted,the result measured by the monitoring system is compared with the monitoring data measured by the trolley,quantitative and qualitative analysis are made for the monitoring curves,warning indicators of settlement,warning level,warning value,and emergency measures are proposed hopefully and corresponding to the monitoring system.Some research results obtained in this paper are listed as follows:(1)Domestic and international monitoring techniques for high-speed railway subgrade settlement are described,trends and research directions of the monitoring techniques forhigh-speed railway subgrade settlement are analyzed,and mechanism of the high-speed railway embankment settlement,disease occurrence,characteristics of ballastless track structure are described.(2)Research is given for the monitoring idea of calculating subgrade settlement by measuring the horizontal inclined deformation of the high-speed railway ballastless track bed(or track plate)so as to monitor and give a warming on the high-speed railway subgrade settlement,and the feasibility of the calculation method is analyzed theoretically.(3)Research is given for the monitoring method of the subgrade settlement based on the developed new monitoring instructions,and includes the installation of the monitoring instruments,the analysis of the measuring accuracy,and the reasonable selection of the monitoring cases.(4)The new monitoring system is carried out at the settlement working point of the operating railway to conduct field experiments,availability of the monitoring method and the monitoring principle are analyzed by the comparison with the monitoring result measured by the existing trolley,which lays the practical foundation for large-scale promotion and application of the subsidence monitoring system in high-speed railway roadbed settlement monitoring areas.(5)Warning indicators of subgrade settlement are proposed hopefully and corresponding to the new monitoring system,settlement is graded according to the indicators,and emergency measures are proposed for each level of settlement.