UNITRACC - Underground Infrastructure Training and Competence Center

Indication: Drill Cuttings Crushed too Finely

Jul 24, 2024

Cracks in Longitudinal Direction and Diagonal Cracks

Jul 24, 2024

Do the Cracks Affect the Entire Pipe Wall?

Jul 24, 2024

Possible Causes of Cracking

Jul 24, 2024

Influence of the Geology on Crack Formation

Jul 24, 2024

Example of Flushing out the Overcut Filled with Soil Material

Jul 24, 2024

Causes for Filling the Overcut with Soil Material

Jul 24, 2024

Causes for Filling the Overcut with Soil Material 2

Jul 24, 2024

Causes for Filling the Overcut with Soil Material 3

Jul 24, 2024

Consequences of a Reduced Overcut

Jul 24, 2024

Buoyancy of Jacking Pipes

Jul 24, 2024

Correction of Positional Deviations

Jul 24, 2024

Buoyant Force

Jul 24, 2024

Buoyant Force and Balance of Forces in the Soil

Jul 24, 2024

Buoyant Force – Permanent Load Effects

Jul 24, 2024

Buoyant Force – Non-Permanent Load Effects

Jul 24, 2024

Buoyant Force – Bedding

Jan 01, 1900

Today, supply and discharge lines are still predominantly installed by using the open-cut method: a trench is dug, the lines are installed. Under the protection of an embankment or sheeting and the trench is filled afterwards.

In the face of the numerous disadvantages as well as the citizens' growing environmental consciousness in the future it is urgently necessary to take trenchless technology into account much stronger than until today as an alternative …

Sep 11, 2008

Definition shaft and building pit

(Image: Starting and target shafts)

Shaft:
Depression in the ground surface that is created by sinking (excavation or vertical boring), with suitable securing, that serves for the underground creation of bore holes with the aid of the methods of trenchless installation and for the transport of humans, machines, substances (spoil, air for ventilation, water, bentonite suspension, etc.) and auxiliary materials (pipes, cables, hoses) as well as power …

Sep 11, 2008

Definition shaft construction and securing

(Image: Starting and target shafts)	Shaft construction: Method for sinking and securing of shafts [Olsha91].

Support (or securing): Measures taken to prevent the collapse of the shaft (with reference to [DS853]) [Stein05a].

Sep 11, 2008

Classification of shafts

In trenchless installation, it is differentiated between:

Starting shaft
Target shaft
Intermediate shaft

(Image: Construction phases of the trenchless installation of sewers on the model of microtunnelling - Phase 2 (Jacking))

Sep 11, 2008

Definition starting, target and intermediate shaft

(Image: Starting and target shafts)	Starting shaft: An auxiliary construction in the form of a shaft from which the jacking is started (based on [DS853]) [Stein05a].
Target shaft: An auxiliary construction in the form of a shaft in which the jacking ends (also called destination shaft) (based on [DS853]) [Stein05a].
Intermediate shaft: Auxiliary structure in the form of a shaft which is passed through planned (e.g. for maintenance, tool change, …

Sep 11, 2008

Starting shaft

(Image: Starting and target shafts)

For instance, in microtunnelling and pipe jacking, the following occurs at the starting shaft:

Installation of the (main) jacking station and the abutment for introducing the jacking forces into the subsoil
Positioning the microtunnelling or shield machine
Installation of the fixed portions of the measuring system
Installation of the individual jacking pipes
Discharging the spoil excavated at the working face …

Sep 11, 2008

Target shaft

(Image: Starting and target shafts)

The duties of a target shaft are greatly determined by the methods in use. In microtunnelling and pipe jacking, it is used mainly for removing the microtunnelling or shield machine.

Target shafts are not used, for instance with blind boring, in the creation of service pipes by means of boring with underground connection to a pipe and sea outfalls in which the microtunnelling or shield machine is removed under …

Sep 11, 2008