stability analysis of photogrammetry models - case studies

Stability analysis of photogrammetry

models - Case studiesJessica Ka Yi Chiu

2020-03-05 NBG Vårsleppet

E39 Rock Cliff above Eastern Portal for Søgne Tunnel

LiDAR X Photogrammetry

Leica P40

Control and scanning points are surveyed by CPOS cm accuracy

DJI Phantom 4 Pro drone

Photogrammetrymodel

LiDAR model

Georeferencing:Agisoft Metashape

(<5 cm accuracy)

Meshing, joint mapping, volume estimation:Maptek Point Studio

ST1 ST2 ST4 ST5LiDAR X PhotogrammetryCloud to Cloud registration(error: 2-4 mm)DGNSS (error 3-9 mm)

Joint orientation Joint spacing Volume

Georeferencing of photogrammetry model

Picking 28 fixed points + 8 controlled pointsusing CloudCompareError ~ 3-3.3 cm

‘Smart query’

‘Extract’

Red+Black: mapped bothmanually and automatically

Black: overlooked by manual mapping

‘Query’ – manual trace mapping

S1

S2S3

S4

S3

S2

S5?

13

651 joints are mapped

Joint Spacing for each joint set

14

Volume estimation

15

Volume estimation – agreed with client

Aog BC

D

E1

F og GE2

A

B

CD

E2FG

E1

A

B

C DE2 F G

E1

E18 Larvik Rock cut failure investigation

Before failture

https://cloud.google.com/maps-platform/terms/#3.-license-.

https://cloud.google.com/maps-platform/terms/#3.-license-.

Before failure: Google Street View screenshotsGenerated by Agisoft Metashape

After failure: Drone + camera picturesGenerated by Agisoft Metashape

Before and after failure

Georeferencing of models by using Ground Control Points surveyed by DGNSS.Accuracy better than 5 cm

NORWEGIAN GEOTECHNICAL INSTITUTENGI.NO

#onsafeground

Joint mapping usingMaptek PointStudio

Joint roughness estimation usingMaptek PointStudio

Volume and distance measurement using PolyWorks

Underground?

(Source: Bever Control)

Hoverings Solutions drone

Autonomous flight beyond line-of-sight (source: Emesent)

Maptek Laser skanner 2018 NGI Photogrammetry 2017 Bever Control Profiler 2019

S1

S4?

S3

S3b

N

S

EW

Symbol SOURCE Quantity

Bever 19

Color Density Concentrations

0.00 - 2.50

2.50 - 5.00

5.00 - 7.50

7.50 - 10.00

10.00 - 12.50

12.50 - 15.00

15.00 - 17.50

17.50 - 20.00

20.00 - 22.50

22.50 - 25.00

Contour Data Pole Vectors

Maximum Density 24.43%

Contour Distribution Fisher

Counting Circle Size 1.0%

Plot Mode Pole Vectors

Vector Count 19 (19 Entries)

Hemisphere Lower

Projection Equal Angle

Rock joint mapping in tunnel (Båndkall)

S1

S3

S3b

S1

S3

N

S

EW


Bever 19


0.00 - 2.00

2.00 - 4.00

4.00 - 6.00

6.00 - 8.00

8.00 - 10.00

10.00 - 12.00

12.00 - 14.00

14.00 - 16.00

16.00 - 18.00

18.00 - 20.00







Hemisphere Lower


N

S

EW


Bever 19


0.00 - 2.50

2.50 - 5.00

5.00 - 7.50

7.50 - 10.00

10.00 - 12.50

12.50 - 15.00

15.00 - 17.50

17.50 - 20.00

20.00 - 22.50

22.50 - 25.00







Hemisphere Lower


S4? S3

S1

S3b S3

S1

S3b

S1

S3

Further applications of 3D models:

Example from E18 Rugtvedt-Dørdahl

>> Parametric Designs of rock support

Example from E18 Rugtvedt-Dørdahl

The what?

A combination of CAD software and programming interface to create 3D geometries.

Grasshopper is a visual programming tool used to create the geometry, and much more…

Rhino is used to visualize results (CAD)

The what?

Geometries are parametric – we can change the parameters to modify the model seamlessly

Geometries are computational – we apply math to create the design

Geometries can be generative– we can iterate the process based on goals to obtain the best solution

The how?It’s like scripting – but simply more intuitive

We can create complex geometries in 3D with little effort – fast and efficient

On this geometry we can perform evaluations and analysis

We can then communicate our design and results using BIM and VR, or export to drawings.

Suitable for development of diciplinemodels in rock support, rock grouting and geotechnical constructions.

Parametric model of rock support in rock slope

NORWEGIAN GEOTECHNICAL INSTITUTENGI.NO

#onsafeground

stability analysis of photogrammetry models - case studies

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