tunnelmodeling and maintanance


LiDAR is the fastest, safest and most accurate way of collect information from underground spaces like tunnels and bridges to construct new structures or monitor and maintain old ones. One cannot survey them in any other means.

Active tunnel construction sites are non-traditional environments for LiDAR scanning and required unique and adaptable solutions.With correct data interpretation techniques, LiDAR technology provides a precise 3-dimensional tool for geo-mechanical assessment of exposed rock in the face and walls. LiDAR data may also be used retroactively for quality control of installed tunnel support.

Traditionally, deformation and change in an underground environment is measured using a series of five or more permanent control points installed around the profile of an excavation. Using LiDAR for profile analysis provides many benefits as compared to traditional monitoring techniques.

 Due to the high density of the point cloud data, the change in profile is able to be fully characterized, and areas of anomalous movement can easily be separated from overall closure trends.

Furthermore, monitoring with LiDAR does not require the permanent installation of control points, therefore monitoring can be completed more quickly after excavation, and scanning is non-invasive therefore no damage is done during the installation of temporary control points.

Tunnel Modeling & Maintenance


Shotcrete thickness verification

Bolt installation verification

Potential leakage mapping

Structural discontinuity evaluation

Surface characterization

Joint spacing measurement

Large scale joint roughness calculation

Analysis of structurally controlled over break

Discontinuity spacing and 3 dimensional models

Prediction of future deformations or large failures

Tunnel alignment verification at chainage locations

Refinement of support design and excavation rate and method

Back calculation of rock mass deformability and other rock mass parameters

Discontinuity orientation measurement and extraction for input into Digital Elevation Modelling(DEM).

Comparison of the design cross-section with the actual cross sections obtained from 3D laser scan data

Geokno India Private Limited