overview on geo 3d project improvement of the tbm tunneling process by using real time information...

Overview on Geo 3D Project

Improvement of the TBM tunneling process by using real time information

Constantin Radu GoguDaniel MonfortVioleta VelascoJordi Font-Capó

Enric Vázquez – SuñeJesús Carrera

GRUPO HIDROLOGÍA SUBTERRÁNEA (UPC)

UPC, November 6, 2008

Content :

- Project goal

- Current trends and situation

- Project overview

- Modeling integrated scheme

- Conclusions & Discussions

Geo 3D - Improvement of the TBM tunneling process by using real time information

Improvement of the TBM tunneling process by real time updating of the geological and of the hydrogeological model, using real time information concerning the geological materials and the hydrogeological and deformation behavior registered during the excavation of the tunnel.


Ideal objective

Project goal


Project goal

Visualization of the geological model (control cabin) continuously updated function of the observations and the tunneling process recorded parameters:

- excavated material type (granulometry and mineralogy),

- hydrogeological parameters (hydraulic conductivity, hydraulic head, fluxes)

- mechanical resistance (cohesion, friction angle)

- soil deformation


Idea

Project goal

Advantage

- Normal conditions: the machine parameters could have an optimal adjustment

- Identification of problematic zones: the excavated material does not coincide with predicted


Project goal

- study and model the hydrogeological parameters the geological information could be really improved

- few applications of groundwater behavior related to tunneling aspects can be found in the literature.

- Hydrogeological parameters are analyzed or modeled to study:

● seepage effects,

● pressures to determine the subsidence, tunnel ring deformations, longitudinal displacements and related consequences.

- Analysis usually is performed to study the execution aspects or the tunnel behavior in time and less for geology prediction.


Existing situation

Current trends and situation



How works the tunneling process ?



Ptop

Applied Pressure at the Tunnel Face

Natural Pressure at the Tunnel Face

Fconf FwaterFground

Confinement Pressure gradient


Pressures interacting on the tunnel face


Approximate settlement ranges observed in tunneling excavated in granular media


50% - 80% 0 - 25%

~ 2-3 dias

0 - 25%

Levantamientos

Asientos Escudo





2

2

2

2

max 2exp

22exp)(

i

y

i

V

i

ySyS s

S(y)

H

y

Smax

i

R

Geometry of the settlement produced by tunnel excavation expressed by the Gaussian curve

with the transition point i = K ×H, where K - ground coefficient; H – Vs – volume of the settlement

Subsidence produced by the tunnel excavation (Peck, 1969)



Study case - Emeriault and Kastinger (2008)

CPI 2

CPI 1

2.25

0.75

5.50

7.48

11.00

Top of the molassesWater level

Ground level

evolution of pore pressures in two cells installed in the tunnel axis:

- located within the tunnel boring machine pass (CPI2) and was destroyed during excavation -located at 0,75 m above the tunnel crown (CPI1).

- homogeneous geology (Toulouse molasses: hard sandy clay with pockets and lenses of very dense sand)

- homogenous geotechnical characteristics - the average cover ranges between 10 and 20 m - groundwater table 4 m below ground level.



Study case - Yamamoto et al. (2003)

- system using geostatistics to evaluate the geological conditions ahead and surrounding of the tunnel face simultaneously with excavation

- relationships between drill energy coefficient in the region ahead of the face of the tunnel derived from the drill logging data and the excavating energy or the rock mass strength



Study case - Yamamoto et al. (2003) The amount of energy required to bore a unit volume of ground “drilled energy coefficient :Ev = (E×N)/(V×A) E – drill energy per strike

N – striking times/sec V – drilling speedA – area of cross-section

The rock mass strengthσc(F) = F/(C1×Pe) σc(F) – rock mass strength

F – thrust loadPe– penetrationC1– constant

The excavating energy Qv = F/A + 2π N×Tr/(A×V) Qv– excavation energy

F – thrust loadA – area of cross-sectionN – cutter revolutions/minTr – cutter torqueV – excavating speed




Evaluating the geological conditions - made in three steps:

- the drill energy coefficient derived from drill logging at each measuring location ahead of the face was converted into excavating energy and rock mass strength based on a predetermined correlation coefficient

- the spatial distribution of these converted values was modeled using the mean function and the covariance function of the spatial structure

- the kriging method was used to estimate the distributions of the rock mass strength and the excavating energy of the area ahead of the face.

- data collection: a large campaign of geophysical and hydrogeological field tests made before, during, and after the tunnel excavation;

- development a hydrogeological model simulating the aquifer behavior during and after the tunnel execution;

- studying the entire set of parameters provided by the tunneling machine during the excavation process together with the variables resulted during the field tests and the hydrogeological models outputs;

- design and the development of a 3D geological spatial data platform designed to manage spatial and temporal data.


Working directions

Project overview


Data collection

Project overview


Data collection

Project overview

Cota (m) Profundidad (m) Cota tubo ranurado (m)

Distancia eje túnel (m)

Pou 1 5.50 30 Ranurado hasta cota -24.5

8

Pou 2 5.50 30 Ranurado hasta cota -24.5

8

SPA-1 5.31 30 Entre -20 y -24 8

SPA-2 5.50 30 Entre -20 y -24 8

SPA-3 5.465 15 Entre -4.5 y -8.5 12

SPA-4 5.42 20 Entre -7.5 y 12.5 13

SPA-5 5.34 20 Entre -9.5 y -13.5 13

SPA-6 5.335 15 Entre -4.5 y -8.5 12


Data collection Nivells pas túnel

1

1.5

2

2.5

3

3.5

21/03

/2008

00:00

21/03

/2008

02:24

21/03

/2008

04:48

21/03

/2008

07:12

21/03

/2008

09:36

21/03

/2008

12:00

21/03

/2008

14:24

21/03

/2008

16:48

21/03

/2008

19:12

21/03

/2008

21:36

22/03

/2008

00:00

temps

Niv

ell

msn

m

CiclesEPBPA3

PA4

PA5

PA6

Posició front +2.4 m secció PA1-PA2

Posició +9.6 m secció PA1-PA2

Posició +13.6m secció PA1-PA2

745 755

Posició -11.8 m secció PA1-PA2

Posició -1m secció PA1-PA2

Col·locació anellArrencada màquina

Project overview


Data collection Piezòmetres PA1 i PA2

-1.5

-1.3

-1.1

-0.9

-0.7

-0.5

-0.3

-0.1

0.1

0.3

0.5

21/0

3/20

08 0

0:00

21/0

3/20

08 0

4:48

21/0

3/20

08 0

9:36

21/0

3/20

08 1

4:24

21/0

3/20

08 1

9:12

22/0

3/20

08 0

0:00

22/0

3/20

08 0

4:48

22/0

3/20

08 0

9:36

22/0

3/20

08 1

4:24

22/0

3/20

08 1

9:12

23/0

3/20

08 0

0:00

Temps

Pro

f. m PA1

PA2

Cicles EPB

Col·locació anellArrencada màquina

-11.8m secció PA2-PA1

+18.6 m secció PA2-PA1

+13.6m secció PA2-PA1

-1m secció PA2-PA1

Project overview


TMB parameters

Current cross-section Recorded vs Predicted

estimated parameters

Analysis Management Visualization Software Platform installed on the TBM

Geological / Geotechnical parameters at the excavation section

(ex. estimated excavating energy, soil strength)

Geological / Geotechnical parameters on the excavation-section - (ex.

estimated soil strength, excavating energy)

Updating the parametres

3D tunnel graphic animation

3D Tunneling model(3D geological model & the tunnel

trajectory)

Deriving the parametres

Updating the model

Initial geological & Hydrogeological Data

Geospatial Database interface (Spatial/Time dependent query and visualization)

3D Interpreted geological Data

Tunnel technical parametres

Hydrogeological & Deformation modeling software (Code Bright)

3D Geologic model

Piezometry and Deformation daily data entry

Soil Displacements

3D Geologic modeling software (gOcad)

TMB parameters


Modeling integrated scheme

3D - Visualization software tests


Conclusions & Discussions

Before the excavation of a tunnel, only surface exposures and boreholes are usually used to assess the geology and the lithology. Their results are extrapolated to the designed tunnel and its surrounding area.

An accurate hydrogeological analysis provides trustful information on the geological characteristics. Because they are time and effort consuming the hydrogeological assessment techniques are almost unused in characterizing the tunneling conditions.



Future analyzing and modeling data in tunnel activity will be taken by software platforms combining the two software types: GIS and CAD. GIS packages and spatial databases will be used manage and visualize spatial data and the geological spatial models are build in dedicated 3D CAD applications.

A prediction model to give fast responses for the lithological uncertainties in the proximity of the tunnel face, could be by focusing the quantification procedure of the soil mass strength and the excavation energy by using soil lithological properties. These two parameters derived from the lithological properties can be compared with the same parameters derived from the TBM.


General - more complex test site- other lithological distribution with more contrasted

characteristics- …. better.. a problematic test site

Geophysics - a deeper electric tomography- seismic tomography- diagraphy

Conclusions & Future work

Data acquisition

Stratigraphy - accurate and detailed granulometry

Geotechnics - geotechnical data acquisition and laboratory tests


Tunneling machine data - data machine parameters with a shorter time step (min)

Excavated material - take more samples on each excavated section


Data acquisition

Soil deformation data - shorter time step- real time data acquisition system


Data analysis - this experience was a learning process - improve data analysis by relating the recorded parameters: (ex. – pressure of injection / hydraulic heads; granulometry/ TMB parameters, etc)- compare soil resistance (CPTU) with TBM parameters (F,M)


Modeling - model the groundwater flux and soil deformation - model 3D is necessary- Geostatistics / ANN (software platform)

Thank you for your attention !

The civil engineers forgot about groundwater !



Not in terms of existence (because it produces a lot of problems … for them)

But … in terms of extracting information !

It means by using groundwater data to better quantify the geological information.

overview on geo 3d project improvement of the tbm tunneling process by using real time information...

Documents

d improvement

d project improvement

hydrogeological model

tunnel behavior

project goal current

machine parameters

geological information

tunnel facegeo