UNITRACC - Underground Infrastructure Training and Competence Center

Damages in pipe jacking

In jacking processes, extensive and irreparable damages are frequently observed, which is due to irregularities of the subsoil.

Although extensive subsoil investigations can reduce the subsoil risk, failures and damages cannot be completely excluded.

(Image: Attention!)

These are the consequences of damages during pipe jacking:

Insufficient quality of the construction execution
Delay
High costs
Environmental impacts

Jan 25, 2005

Errors and consequences of damage

Damages in pipe jacking - statistics

(Image: Distribution of damages in pipe jacking in Germany (source: IFB, Hanover 1993))

Aug 28, 2008

Errors and consequences of damage

Indication: Leaking Pipe Connection

Aug 25, 2008

Errors and consequences of damage

Jul 01, 2021

Utility Tunnelling - Pipe jacking - Part 2

This presentation is part of the series of presentations "Utility Tunnelling" and deals with the various types of shield machines, the removal of obstacles and possible errors in pipe jacking.

Jan 01, 1900

Underground pipelines and utilities are predominantly installed by using the tradition open-cut (i.e., cut and fill) method: a trench is dug, the lines are installed by constructing proper embankment or sheeting or using a trench box, and the trench is filled afterwards.

In the face of the numerous challenges (e.g., urbanization, densely populated areas) as well as growing environmental consciousness, it is important to consider trenchless technology …

Aug 08, 2008

Description of the technique

Definition pipe jacking

(Image: Manned techniques)

(Image: Steerable techniques)

Pipe jacking:
A system of directly installing pipes behind a cutting head and/or shield, by hydraulic jacking from a drive shaft, such that the pipes form a string in the ground [DINEN12889:2000].

The manned or unmanned technique, in which jacking pipes with a clear diameter ≥ 1200 mm (not to be confused with DN/ID) are jacked directly behind a shield machine from a starting shaft by pressing …

Aug 08, 2008

Description of the technique

Pipe Jacking - Technical Components

Aug 07, 2008

Description of the technique

Aug 08, 2008

Main jacking station

Main Jacking Station - Design

Aug 08, 2008

Definition shield machine

Aug 08, 2008

Properties of shield machines

Jan 25, 2005

Functions of the shield machine

The duties of the shield machine in pipe jacking are as follows [Scher77a]:

To protect the personnel,
To create the necessary cavity so that the following pipe string can be pressed in with a minimum degree of soil deformation and with the lowest possible skin friction,
To protect the cavity until the jacking pipes can finally carry all the loads and forces,
To secure the working face against collapsing soil and rock as well as groundwater, …

Aug 08, 2008

Design of shield machines

2-component shield machine

(Image: Design of a 2-component shield machine)

3-component shield machine

(Image: Design of a 3-component shield machine)

Jan 25, 2005

Shield machine types - overview

(Image: Overview of shield machine types)

Aug 08, 2008

Definition open shields

Open shields:
Shield machine without pressure tight sealing between the working face and the following pipe string [Stein05a].

Open shields do not have a pressure-tight seal between the working face and the subsequent pipe string. They are characterized by relatively good access to the working face and easy-to-use machine technique.

(Image: Hand shields - Overall view of a hand shield (external diameter 2098 mm) [FI-Nishi]) (Image: Open shield) (Image: …

Aug 08, 2008

Shield machines with partial excavation

Shield machines with partial excavation feature an open (SM-T1 or SM-T2) or closed shield (SM-T3 or SMT4) and partial loosening of the soil or material at the working face.

Shield machines with partial excavation of the working face are grouped according to the method of excavation into:

Shield machines with partial excavation by hand (hand shields)
Shield machines with mechanical partial excavation
Shield machines with hydraulic partial excavation

Aug 08, 2008

Definition closed shields

Closed shields:
Shield machines equipped with a pressure bulkhead between the working face and the shield tail in order to build up an artificial pressure at the working face [Stein05a].

(Image: Possible designs of boring heads for earth pressure balance shields - Shield with eight-spoke cutting wheel and circumferential rim (external diameter 3100 mm) [Breme])

Closed shields are – depending on the used pressure balancing fluid – executed with …

Aug 08, 2008

Shield machines with full-face excavation

Shield machines with full-face excavation (SM-V) differ from those with partial excavation (SM-T) in that they process and loosen the whole working face in one working step by means of a rotating boring head equipped with corresponding excavation tools.

(Image: Shield machines with full-face excavation - Working face with natural support SM-V1)	(Image: Shield machines with full-face excavation - Working face with mechanical support SM-V2)
(Image: …

Aug 07, 2008

Shield machines

Aug 08, 2008

Partial cutting machines - excavation machines

Excavation machines

(Image: Attention!) Excavation machines are used with shield machines with partial excavation. Operating and steering of the shield machine are carried out directly at the site by a machine operator who has a continuous view of the working face.
(Image: Shield machine with fixed installed boom cutting machine - With axial cutting head)	(Image: Axial cutter head of the boom cutting machine equipped with round shank cutter bits)	(Image: Principles …

Aug 08, 2008

Partial cutting machines - excavation machines

Excavation machines - classification

Aug 08, 2008

Full-face cutting machines - design of the cutting head

Design of the cutter head

Aug 08, 2008

Full-face cutting machines - design of the cutting head

Cutting wheel

(Image: Three-spoke rim cutting wheel with scraper teeth (standard bore head) [FI-Rasa])

The cutting wheel is a largely openly designed drilling head that is not used for the mechanical support of the working face. Their advantages lie with the low coverage and thus the good accessibility of the working face when needed. A distinction is made between the spoke and the rim cutting wheel [Maidl98].

(Image: Possible designs of boring heads for earth …

Aug 08, 2008