1. Measurement of Landslide Movement with 3D Laser Scanner ASANO, Hiroki Erosion and Sediment Control Research Group Public Works Research Institute

2. Contents Most observation techniques and problem Outline of 3D Laser Mirror Scanner Attempt of landslide movement measurement with 3D Laser Scanner Result of movement measurement Summary

3. When landslide calamity occurs Based on the site situation and the observation value (ground expansion and contraction meter etc.). ・ The judgment is demanded promptly. ・ Appropriate measures is demanded. Hard measures ： First aid restoration worker Software measures ： Precaution and shelter recommendation

4. Observation technique at calamity suddenly Watch with CCD cameras Watch with ground expansion and contraction meter

5. Concept chart of watch at calamity

6. Ground expansion and contraction meter crack Storage box Paling

7. Principle of ground expansion and contraction meter Movement of landslide Inn bar line Rotation of drum Record pen Recording paper

8. Drum of ground expansion and contraction meter

9. Example of setting up ground expansion and contraction meter

10. Insufficient point of ground expansion and contraction meter The installation and the measurement are difficult in the place with danger. It takes time for the installation (The expansion and contraction meter is one/day). The installation and the observation at nighttime are difficult.

11. laser scanner landslide Measurement image of 3D scanner

12. 3D Laser Scanner

13. Composition of 3D laser scanner ① range finder electronics of the 3D scanner LMS-Z210 ② laser beam ③ rotating polygon ④ slow scan ("frame scan") ⑤ ECP compatible LPT printer port ⑥ PC ⑦ software

14. Outline of 3D laser scanner Measurement range ： 2 ～ 350, reflectivity >= 80 % Measurement accuracy ： +/- 2.5 cm, in the worst case +/- 10 cm Range which can be measured ： 80°×300° total Beam divergence ： approx. 3 mrad Eye safety ： Class 1 for the scanned beam

15. Characteristic of 3D laser scanner The pulse of the laser beam is launched repeatedly at very short intervals of time. Each pulse reflects, the time to returning is measured, and the distance is measured. The direction of the laser beam is changed and three- dimensional shape is scanned. ＝ The measurement principle is the same as the machine and the total station etc. of a general light wave measurement. A new part is technically a method of scanning It is possible to measure without setting up the reflection mirror.

16. L ΔｔΔｔ Ｌ＝ｃ ・ Δ ｔ （片道） laser scanner laser pulse t t t

17. laser pulse mirror laser scanner

18. laser scanner

19. laser scanner

20. laser scanner Extension angle of 3mrad

21. The measurement data displayed to personal-computer

22. Computational graphic

24. Landslide measurement which uses 3D laser scanner Geographical features measurement of landslide →Making of ＤＥＭ（ digital elevation model ） →Making of topographical map Measurement two or more times →Grasp of displacement situation Making of vector chart Grasp of range of landslide movement

25. Ｘ Ｙ Ｚ laser scanner Overlapping the data is difficult if there is no points in evaluation.

26. point （Ｘ，Ｙ，Ｚ） Ｘ Ｙ Ｚ laser scanner

27. ＸＹ Ｚ point （Ｘ，Ｙ，Ｚ） Ｘ Ｙ Ｚ laser scanner

28. Reflection seal

29. Situation of measurement

30. laser scanner Range of measurement （ top and bottom ） 40° （ right and left ） 85° Landslide

31. Procedure of the measurement data analysis ① The data measurement ② The point data making ④ Making of TIN model ⑤ Plan and section chart making ③ Movement amount calculation

32. Vector chart

33. Frequency distribution of measurement error

34. 11 月 16 日 地すべり末端 11 月 24 日

35. Landslide movement range chart

36. Summary ① 7cm or less roughly against the amount of the movement of 15-20cm. ② The respect grasp of the range of the movement was possible because of overlapping the topographical map before and behind the movement amount. ③ The examination is scheduled to be advanced for the improvement of the accuracy in the future.

37. Finished Thank you for your attention.