The Ground Requires Specific Solutions.
Herrenknecht Provides them.
The geological and hydraulic information about the soil forms the basis for planning and executing tunnelling and pipe jacking projects.
Consequently, the expert evaluation of geological reports is of great importance because it enables soil conditions to be fully taken into account in mechanical design.
Soil investigations provide the basic data for selecting tunnelling methods and cutting wheel tools that will cut through the native ground efficiently and economically. The classical fields of application of tunnel face support systems (slurry or earth pressure support) are defined by the types of soil or their permeability coefficients. Innovations based on additives (foam, polymers, tensides) in the field of chemical process engineering have extended the classical fields of application of the respective types of processes still further, resulting in a greater degree of flexibility of the machines used. It is absolutely essential that all those involved in the project have sufficient knowledge of the interactions between soil, additive and machine.
The most important ground or rock-mechanical parameters for designing a tunnel boring machine are:
- the grading curve
- ground water penetration
- the consistency limits
- the rock/clay mineralogy
- the quality of the rock
- the hardness of the rock
Apart from the choice of process, particular attention must also be paid to the design of the cutting wheel. Here too the soil parameters have a great influence on the choice of design since the cutter rings used on hard rock, just like scraper tools used principally on cohesive loose soil, are exposed to abrasion and clogging by the soil.
Herrenknecht AG fulfills these requirements by making project-specific adaptations to the process and excavation techniques.
In order to achieve optimum tunnelling, even in tunnel faces supported by slurry pressure, an extensive knowledge of geology is also necessary to prepare the support medium, bentonite, by means of a separation plant.
The tunnel boring machine concept devised by Herrenknecht AG therefore incorporates the expert implementation of hydrogeological reports on which the mechanical design is based. At Herrenknecht, engineering technicians, construction engineers and process engineers collaborate in order to fully meet both the heterogeneous requirements of the soil and the requirements of the customer.
If you have any further questions or need more information on your current or future project, please write an e-mail to:
traffic(at)herrenknecht.de (for traffic tunnelling)
utility(at)herrenknecht.de (for utility tunnelling)
