Subproject A1 (finished July 2014)


The goal of subproject A1 is to gain knowledge and experience about the interactions of ground conditions and machine behavior for execution planning, project simulations and excavation support for prospective projects. Additionally focus is placed on tool wear and wear prediction. The primary work comprises the detailed documentation of the actual ground conditions inside of 4 open cut stations in the course of construction of Wehrhahn-Linie metro project in Düsseldorf, Germany. Here, tunnel excavation was carried out before the excavation of the stations and allowed thus very detailed insight into the real ground conditions. 44 site inspections were conducted within two years, over 200 soil samples were taken and analyzed in the laboratory, numerous geological sections were documented and nearly 200 meter of dynamic probing (DPL) were carried out.

Figure 1: Project site of Düsseldorf Wehrhahn-Linie; left side: exhumed tunnel within an open cut station; middle: dynamic probing; right side: tunnel surrounding soils

Because of the very homogeneous ground conditions in this special case, the investigation of technical or “manmade“ (excavation-independent) influences on machine raw data became possible and finally was found to be essential for any kind of analysis aiming on ground investigation. For the comparison of the resulting excavation-specific data components of different projects, cutting wheel design (size, opening ratio, tool assembly) has to be considered as well and forces therefore may be scaled (at least) to the cutting wheel area (Fig. 2).

Figure 2: Contact forces per unit area of the cutting wheel of two hydro shield projects, both driven in sands and in gravels with similar penetration rates of 15 to 25 mm/U, but much higher soil strength properties in right case (except the excavation of 4 concrete walls (peaks) in left case)

Finally soil strength properties seem to have the major impact on machine performance (much more important than the soil type itself) as well as on wear aspects. Additionally it was found that in most cases superposition of many different effects on the excavation-specific data components (mainly excavation resistance, clogging or wear effects) will be realized in practice.





List of publications

 

Doctoral theses

2014
Düllmann, J., Ingenieurgeologische Untersuchungen zur Optimierung von Leistungs- und Verschleissprognosen bei Hydroschildvortrieben im Lockergestein, in: , 2014, Link
 

Journals

2013
Hollmann, F., Thewes, M., Assessment method for clay clogging and disintegration of fines in mechanised tunnelling, Tunnelling and Underground Space Technology, Volume: 37, pages 96-106, 2013, DOI
 

Books & Contribution in books

2014
Thewes, M., Tunnelbau im Schildvortrieb – Verfahrenstechniken und Planungsgrundlagen, in: Bergmeister, K., Fingerloos, F., Wörner, J. -D., (eds.), Beton-Kalender 2014: Unterirdisches Bauen, Grundbau, Eurocode 7, Ernst & Sohn, pages 121 – 170, 2014
 

Conference Proceedings

2013
Düllmann, J., Hollmann, F., Thewes, M., Alber, M., Analysis of Soil-Machine-Interactions (Part 1):Processing of TBM-Machine-Data and Extraction of Excavation-specific Data, in: Proceedings of the Third International Conference on Computational Methods in Tunnelling and Subsurface Engineering, Ruhr-University Bochum, Aedificatio, pages 621-634, 2013
 
Hollmann, F., Düllmann, J., Thewes, M., Alber, M., Analysis of Soil-Machine-Interactions (Part 2): Influences on the Excavation-specific Data of TBM-Machine Data, in: Proceedings of the Third International Conference on Computational Methods in Tunnelling and Subsurface Engineering, Ruhr-University Bochum, Aedificatio, pages 635-648, 2013