Condition assessment and inspection of highway bridges using terrestrial laser scanner
Authors: Beshr Ashraf A.A. , Ghazi Zeinab , Heneash Usama 
Published: January 2025

Purpose
In any developing country, including Egypt, highway bridges are essential to the sustained growth of urban areas. It is also regarded as one of the significant construction projects that contribute to improve and facilitate transportation and save a lot of travel time. Bridges have some defects and deformation as a result of climatic changes, vehicle loads and express traffic and accidents, which necessitate continual observation and monitoring to repair any defect before it increases. One of the main reinforced bridges in Egypt is Kafr El-Sheikh highway bridge which is the subject of this effort. This paper focuses on an integrated monitoring system for assessing the deformation behavior of this bridge.

Design/methodology/approach
The coordinates of monitoring stations distributed throughout the structure are pertinent data for evaluating the deformation of this structure derived from geodetic observations. These points’ coordinates are determined with reference to control fixed points. Therefore, any distortions in the coordinates of control points between any two successive observational epochs will have an impact on the structural deformation values. This paper investigates the application of multiparameter transformation for structural health monitoring of bridges in order to address this problem. Statistical tests of geodetic measurements using the F-Fisher criterion at a 98% confidence level are also included. Two observations epochs were carried out using terrestrial laser scanner (TLS) in December 2021 and October 2022. In each epoch, visual inspection is carried out to identify the defects in the pavement layer of the bridge and the defects in the body of the bridge itself, this is done before field monitoring with TLS.

Findings
The potential application of terrestrial laser scanning (TLS) is investigated in this research for studying the condition assessment and inspection of highway bridge in Kafr El-Sheikh city in Egypt. The suggested 3D TLS as a geodetic monitoring methods for highway bridges can yield important information on the movement and deformation of structural elements. TLS can therefore be a useful substitute for the outdated, conventional methods. Using seven criteria, the transformation methodology can eliminate systematic mistakes in measurements between two successive epochs, making it a useful tool for calculating the values of structural deformation. A statistical test based on the F-Fisher criterion has a 98% confidence level and may be used to calculate the values of deformation for any structure, such as a highway bridge between any two observational epochs.

Originality/value
This paper focuses on an integrated monitoring system for assessing the deformation behavior of highway bridges. The paper seeks to cover the following points: 1. Creating an accurate observation method using a 3D laser scanner to scan, track and assess the R.C. highway bridge condition in Kafr El-Sheikh city, Egypt. 2. Using TLS observations to identify and quantify the size of defects and deformation in the pavement surface, R.C main system of the studied bridge. 3. Investigating the possibilities of determining the monitoring points’ displacement on the bridge main system using a seven-parameter transformation.