Intergrated Space-Air-Train-Ground Muti-source Techniques for Early Detection of Subgrade Disasters and Service Status of Railway Subgrade

Objectives Because of high frequency of extreme weather, railway subgrade disaster shows a trend of increasing, great harmfulness and is hard to detect in advance. Even a small-size subgrade disaster may cause railway paralysis, which prevents the development of transportation. Many incidents illustrate that the earliest subgrade disaster always appeared in areas where no case ever reported before. It means that traditional monitoring methods are hard to detect hidden danger area. Thus, a promising method is urgent to be proposed for meeting the monitoring requirement for railway safety.

Methods First, the characteristics of subgrade disaster are summarized under different disaster-pregnant environments, and the advantages of various monitoring methods are discussed to find a collaborative applications method for early identification of subgrade disaster. The potential hazards that may cause damage to subgrade structure and the deterioration degree of subgrade are considered as the main monitoring object of subgrade service status, including subgrade deformation monitoring, structural health monitoring, geological hazard monitoring along the railway, track irregularity, and external environmental monitoring. Second, an investigative approach based on the integration of space-air-train-ground muti-source techniques is proposed to detect the geohazards and monitor the service status of railway subgrade. It means that collaborative application of different monitoring methods, cooperative analysis of different scales and resolutions data and collaboration of between various railway departments are required. Two monitoring schemes for subgrade disasters and service status of subgrade are proposed based on the integration of multi-source and multi-scale monitoring technique. Finally, the development direction of subgrade service status monitoring is discussed.

Results and Conclusions This monitoring system has been applied in the identification of subgrade service status in the Shanghai-Nanjing high speed railway, which can quickly investigate the location of the disasters and the deterioration degree of subgrade.