APPLICABILITY OF THREE-DIMENSIONAL POINT CLOUD DATA TO MAINTENANCE OF ROADBED IN RAILWAY TUNNELS

Abstract

 This paper shows applicability of three-dimensional point cloud data to manintenance of roadbed in railway tunnels.

 Defects such as cracks, settlement and heaving are observed on roadbed in some tunnels. Among these defects, settlement of roadbed may affect the safety of train operation and stability of tunnel structure. Therefore, authors need to evaluate the soundness of settlement accurately through inspections. Moreover, the efficiency of inspection is also important. This is because the inspecions of railway tunnels are usually conducted after and before the train oeperation, and the duration for insection is limited.

 We measured three-dimensional point cloud data of railway roadbed in tunnels and rail facilities on RC slabs. Point cloud data are measured by Mobile Mapping System. Then, we calculated the gap between the bottom of rail and surface of RC slab continuously in the longitudinal direction of tunnels, using the data from three-dimensional point cloud data.

 Through the validation of gap data, we verified that the gap data capture the feature of settlement of roadbed. Moreover, we found that the data added the record of track maintenance could show the situation of roadbed more acculately.

 With the course of consideration about continuous gap data and record of track maintenance, we confirmed the possibility of improvement in accuracy and efficienty of visual inspection on roadbed regarding settlement.