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Despite many attempts, it has not yet been possible to develop a universal shield machine that is able to carry out jacking under all possible geological and hydrogeological conditions and jacking-specific limiting conditions (such as jacking distance, nominal pipe size, depth of cover, etc.) as well as taking economic, ecological, logistical and safety aspects into account. As has been seen in the previous sections, every type of shield has limits … |
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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. The characteristic feature of these machines is the type of support for the working face (Tabelle 9.2) (Tabelle 9.2). |
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Sep 19, 2005 Trenchless Technology for Installation of Cables and Pipelines Shield machines for jacking pipes with cross sections deviating from the circular Because of its modular structure, the DPLEX shield jacking method (Developing Parallel Link Excavating Shield Method) [FI-DAIHO], permits shield jacking with circular, rectangular or arc shaped cross section (Bild 9.2.3.1). The removal of the soil at the working face is achieved by means of a correspondingly shaped cutting frame rotating eccentrically about crankshafts (Bild 9.2.3.1) (Bild 9.2.3.1) [Watan97] [Kashi97].
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Sep 19, 2005 Trenchless Technology for Installation of Cables and Pipelines Shield machines for jacking pipes with cross sections deviating from the circular
The shield machine from the Japanese Takenaka Ltd. [FI-Takan] … |
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According to EN 12336 [DINEN12336:1996], a shield machine is any machine for the excavation of tunnels, in which the excavation is carried out, either by hand, mechanically or hydraulically within the protection of a shield whereby the shield is self supporting and is driven with thrust and/or steering jacks. The feature of shield machines, also called shields, for pipe jacking, is that the thrust jacks (jacking cylinders) are situated not in the … |
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(Image: SS MOLE method - longitudinal section [FI-Toyot]) The SS MOLE (SS = Super Slurry) [FI-Toyot] is a microtunnelling or shield machine with fluid supported working face and a pneumatic conveying system (Abschnitt 8.4.1.2). It consists of the boring and steering head or front shield segment and, depending on the nominal pipe size, of two or three joined articulated trailing shield segments (Bild 9.5.1). The dimensions are found in Tabelle 9.5.1 |
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(Image: ULTIMATE METHOD - arrangement of the articulations and steering cylinders with reference to [FI-Kidoh] [Image: S&P GmbH]) The ULTIMATE METHOD (Bild 9.5.2) [FI-Kidoh] works with fluid supported or earth pressure balanced working face in the nominal size range of DN/ID 800 to DN/ID 3000. Preferred areas of application depending on the distribution of the particles are shown in Bild 9.5.2 and Bild 9.5.2. This method is very similar to the SS MOLE (… |
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According to the German "Sicherheitsregeln für Bauarbeiten unter Tage" ("Safety Underground Regulations for Construction Work") [BGR160], which also applies to pipe jacking, working places and traffic paths underground must be ventilated such that:
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Underground pipelines and utilities are predominantly installed by using the traditional open-cut method (i.e., cut and fill): 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 … |
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(Image: Manned techniques) (Image: Steerable techniques) Pipe jacking: |
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May 18, 2020 |
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A shield machine is a steerable sheeting construction, in the protection of which the soil / rock on the working face is excavated manually, mechanically or hydraulically. It consists of at least two flexible connected steel pipe pieces, the front shield segment and the trailing shield segment, which is supported by the jacking pipe string. A distinction is made here between open and closed shields or shields with partial and full face excavation. |
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(Image: Overview of shield machine types) |
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Open shields: 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: … |
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