Laser scanning technology uses a laser rangefinder to quickly acquire 3D coordinates on the surface of objects. It has various applications in civil engineering projects for tasks such as 3D modeling of structures, railway and track surveying, dam monitoring, and deformation monitoring. A case study described how laser scanning was used to accurately map and analyze cracks in a dam in Portugal. The document provided details on the basic working principles, advantages, and some limitations of laser scanning technology.

1. LASER SCANNING TECHNOLOGY IN CIVIL ENGINEERING
CONSTRUCTION PROJECTS
Presented By
SURYA C.D
ME Construction Management
1

2. CONTENTS
 Objectives 3
 Scope 4
 What is Laser Scanning ? 5
 Why is Laser Scanning ? 10
 Major applications in Civil Engineering 11
Case Study 19
 Disadvantages 24
 Conclusion 25
References 26
2Date:30/1/2011
SLIDE NUMBER

3. OBJECTIVES
 To reveal the applications of Laser Scanning Technology in Civil
Engineering construction Projects
 To reveal the benefits of using Laser Scanning technology in
construction field
To show the simple working of Laser Scanner.
3
Date: 25-06-2016

4. SCOPE
 Used mainly for 3D modeling, dam monitoring etc.
 Used in construction manufacturing plants, airports ,hospitals
bridges etc.
Increases speed and accuracy of plans, elevations, profiles, and
volume and area calculations.
Valuable tool for reduction of construction costs
Ensure fast & accurate data whenever required.
425-06-2016

5. What is Laser Scanner ?
LASER
SCANNER
Laser Unit
Rotating Unit
Control And
Recording
Unit
Ranging
Unit
5
25-06-2016

6.  Detailed 3D positioning of a structure can be made.
 Provide full FOV (Full field of view)
 Advanced timing technology
 Accurate enough up to 2 mm resolution
 Long range up to about 300 m with good reflective surfaces.
 Cannot be easily set up over a known point (heavy)
Characteristics
6
25-06-2016

7. Scanner Specifications
Speed-5000 points per second
360 degree field of view
Weighs-13 Kg to 15 Kg
340mm deep & 270 mm wide
Requires electric power to operate.
7
25-06-2016

8. Basic Concept
825-06-2016
Date:30/1/2011

9. Fig 1.1: 3d laser scanner
9
Date:30/1/2011

10. Why Laser scanning ?
Higher project costs
Missed schedules
Operations & maintenance inefficiencies
and problems
Safety problems
10
Date:30/1/2011

11. Applications
11
Date:30/1/2011

12. 3D modeling
• Data Acquisition
• Data processing
• Modeling
Steps Involved:-
12Date:30/1/2011

13. STEP 1: Target the structure
13
Date:30/1/2011
Fig. 3.1 Targeting bridge

14. STEP 2 : Point Clouding
14
Date:30/1/2011
Fig.3.2 Point clouding

15. STEP 3 : Modeling / Meshing
15
25-06-2016 Fig. 3.3 Mesh model

16. LST for Railway And track Survey
The Scanner is mounted on a rail vehicle
The Operator moves this vehicle over the
rail
Clearance analysis
• Vegetation ,signal signs, tunnels
Profile of alignment of rails is recorded.
16
Date:30/1/2011
Fig.4.1 Scanner installed in rail vehicle

17.  Capturing the obstacles
near by track
Maintenance of track is carried out
 Ballast monitoring using mobile 3D
laser scanner
Under normal conditions, the 3D mobile laser scanner map
features such as signs, lights etc.
17Date:30/1/2011
Fig. 4.2.
Fig.4.3.

18. LST for Dam Monitoring
Monitoring –evaluating the structural safety of dams
Surface displacements are important quantities to be
determined
18Date:30/1/2011

19. 19
Date:30/1/2011
Case study
Alto ceira is dam situated in portugal
Crack surveying and mapping -- major problems of dam
Cracks wider than 2 or 3mm are to be surveyed.
 The main challenge in dam monitoring – resolution of
images rather than metric quality

20.  3stations have been set up for the scanner
Perspective view of the dam is obtained
20
Date:30/1/2011

21.  Processing and modeling is done by meshing
 Orto images were created
21
Date:30/1/2011

22.  Vectorization using CAD software
 Association of CAD and DBMS
 Accurate model of dam with cracks is obtained and can be
then analyzed
22
Date:30/1/2011

23. Other applications
Deformation monitoring
Distance measurement
Determine building maintenance requirements
Helps in determination of earthwork quantities
Used to measure bridge camber
23
Date:30/1/2011

24. When scanning outside, vegetation such as trees pose a major
obstacle
Power stability is an issue for continuous usage.
Weather must be considered for outside scan.
Major Disadvantages
24
Date:30/1/2011

25. Conclusion
Possibilities of laser scanning in civil engineering is limitless
Reliable technology
Gives high fidelity data
Enable Precise and accurate 3D model of any structure
25
Date:30/1/2011

26. 26
References
[1] Jocea Andreea Florinas,”3D spatial data acquisition and modeling of
Anghel saligney monument using terrestrial laser scanning” Vol
2(15),2012,pp.2-5
[2] A Bernini’s, “Terrestrial laser scanning-civil engineering applications” Vol
XXXVIII, Part 5,2010
[3] Pedro Arias and Higino Gonzalez, “Novel method to determine laser scanner
accuracy for applications in civil engineering “Vol XLII,No. 1,2012
[4] Arias, J Armesto, M solla “ Terrestrial laser scanning and non parametric
methods in masonry arches inspection” Vol XXXVIII,2010
[5] WIKIPEDIA,http//www.wikipedia.com//
Date:30/1/2011

27. 27