Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

1 / 10 Febr. 14-2007

Numerical Modeling of theIKT-Pipe Jacking Simulator ND 1600

IKT – Institute for Underground Infrastructure

University of Applied SciencesDepartment of Civil Engineering

Contractor:

Client:

Working Group for Structural Analysis and Computer Science

- Preliminary Report -

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

2 / 10 Febr. 14-2007

Finite Element Method is applicable for the explanation of • coupled pipes displacement phenomenon,• stress distribution in intermediate layers including non

linear geometrical and physical behavior and • forces and friction between pipe and soil

Research Goals

Assistance for experimental work to • explain measurement phenomena like displacementsand jacking forces,

• plan further steps and • define needs of additional measure data

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

3 / 10 Febr. 14-2007

1. Description of the Finite Element Model

Bild 1: Isometrische Ansicht des FE-Modells

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusionyz

x

Springline, left

Springline, right

Fig. 1 Symmetric Finite Element Model with dimensions of the IKT-Pipe Jacking Simulator: ND 1600, L = 16.2 m

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

4 / 10 Febr. 14-2007

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

String of 5 pipes

y

x

z

Side bedding

Intermediate wooden layer

Concrete pipeFig. 2 Meshed Finite Element Model

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

5 / 10 Febr. 14-2007

2. First result, Load case „Curve“

Fig. 4 Finite Element Model for load case „Curve”

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

Fig. 3 Pipe arrangement for load case „Curve“

= 191 mm

R = 540 m

x

y

Fx

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

6 / 10 Febr. 14-2007

end pipe rotation

Fig. 6 Deformations in y-direction (scaling factor 15)

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

y

z x

R = 540 m

Fig. 5 Mises stresses for the load case „Curve” (scaling factor 1)

y

xz

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

7 / 10 Febr. 14-2007

Fig 7a Jacking forces Fy, measured at the simulator

Fig. 7b Jacking forces Fy, calculated by the FE-Model

[kN] [kN] -363 309 341 328 315 115 -26073

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

y

x

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

8 / 10 Febr. 14-2007

Fig. 8 Distribution of contact stresses σx in the intermediate wooden layers

and eccentricity ey of the axial forces

ey = -301 mmey = -658 mm

ey = -673 mmey = -336 mm

y

x

z

pipe 1-2 pipe 2-3pipe 3-4 pipe 4-5

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

9 / 10 Febr. 14-2007

3. Conclusion3.1 Recommendations for further experiments

• Look for equilibrium ∑Fy = 0 in the horizontal direction

• Deformations and flexibility due to transversal loads Fy

• Evaluate angle differences and gaps width betweenneighbouring pipes

• Measure orthogonality of the pipe end planes after dismantlingthe simulator

3.2 Phenomena in real pipe jacking situations

• Eccentricity of the axial forces and rotation of the end pipes in curves

• Bedding reactions of the end pipes in the surrounding soil

• Friction caused by these reactions to be added to the total jacking force ∑Fx

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

Prof. Dr.-Ing. B. FalterDipl.-Ing. F. Holthoff___________________

Numerical Modeling of the IKT-Pipe Jacking Simulator ND 1600

10 / 10 Febr. 14-2007

References

1. Description of the FE-Model

2. First resultsLoad case „Curve“

3. Conclusion

1. IKT – Institut für unterirdische Infrastruktur: Forschungsantrag2. ABAQUS/Standard, Version 6.6, Hibbitt, Karlsson & Sorensen, Inc.,

Handbuch, 20063. Scherle, M.: Rohrvortrieb, Band 2: Statik, Planung, Ausführung.

Bauverlag GmbH, Wiesbaden und Berlin (1977)4. Stein, D.: Grabenloser Leitungsbau. Ernst & Sohn, Berlin 20035. Verburg, N.: An analysis of friction by microtunnelling. Final report TU Delft,

Dec. 20066. Bosseler, B.; Liebscher, M.; Redmann, A.: Simulation von Rohrvortrieben

im Maßstab 1:1. 3R international (45) H. 12/2006 7. Arbeitsblatt DWA-A 125: Rohrvortrieb und verwandte Verfahren.

Entwurf Mai 20068. Arbeitsblatt ATV-A 161: Statische Berechnung von Vortriebsrohren.

Jan. 1990 sowie Entwurf 2. Auflage 2007