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In the KCMM-1500 A Dash method (Bild 8.4.1.3) and KCMM 1500 BEAVER II method (Bild 8.4.1.3) (Bild 8.4.1.3) [FI-KCMM], the transport of the spoil, in contrast to the DEINO TYPE or MTB-P method (Abschnitt 8.4.1.1), is achieved through positive air pressure according to the principle of plug flow. The spoil in the excavation chamber is pressed into the discharge pipe (DN/ID 50) and is transported from there with the aid of a further jet of air to a vacuum … |
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Representative equipment for microtunnelling with pneumatic spoil removal in a two-phase operation are the KCMM-1500 Mark II and KCMM-mini methods [FI-KCMM] [Kaoru97]. The method of operation and sequence of these two methods is basically identical with those of single phase jacking (Abschnitt 8.4.1.1). In this case, the pneumatic spoil removal is also based on the principle of plug flow with the pressure plants presented in Abschnitt 8.4.1.3. After … |
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Microtunnelling with pneumatic spoil removal, called microtunnelling with spoil removal by vacuum in EN 12889 [DINEN12889:2000] or also microtunnelling with air or pneumatic conveying in practice, is characterized by single or two-phase jacking of pipes … |
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(Image: Principle of the LUNDBY method with spoil removal by a scraper arrangement with reference to [FI-Skansb] [Image: S&P GmbH]) Microtunnelling methods with spoil removal by other mechanical means are characterized by the jacking of pipes with simultaneous excavation of soil at the working face by means of a boring head and continuous or discontinuous conveying of soil using methods other than the above-mentioned mechanical ones (Abschnitt 8.2) [… |
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In the PERIMOLE TPM method (Bild 8.6.1) [FI-Isekib], the cone-shaped displacement and steering head is divided into two. The cone point and cone rump rotate eccentrically in opposite directions about their common axis during jacking and in this way displace the soil (Bild 8.6.1) [Wilhe99a].
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In the ACEMOLE PL 30 method (PL = Press-in Long Distance) [FI-NTTa] (Bild 8.6.2), the displacement and steering head consists of a closed blunt cylinder that is extended hydraulically for soil displacement and, if required for steering, can be angled a maximum of ± 1.5%. After completing the stroke, the pipe string and the microtunnelling machine are advanced by the jacking station by the amount of the stroke (Bild 8.6.2) (Bild 8.6.2) (Bild 8.6.2) |
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(Image: HERRENKNECHT AVB microtunnelling method with soil displacement [FI-Herreb]) Microtunnelling machines of the HERRENKNECHT AVB type possess a coned displacement and steering head at whose point a rotating three-spoked rim cutting wheel (Bild 8.6.3) is arranged. The purpose of the cutting wheel is to loosen the in situ subsoil in front of the steering head and it is additionally equipped with a high pressure jet. The excavation tools are capable … |
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Microtunnelling methods with soil displacement are used exclusively in displaceable soils with or without groundwater (Abschnitt 4.3.5.6). The areas of application of the above-mentioned soil displacement methods can be found on Tabelle 8.6.4. (Table: Areas of application of microtunnelling methods with soil displacement according to the manufacturer's information) Microtunnelling methods with soil displacement are at present much used in Bangkok. The … |
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The variant of microtunnelling according to the principle of soil displacement (Abschnitt 6) is not mentioned in EN 12889 [DINEN12889:2000] even though at the time of its preparation, this method was already being used in practice. The group of microtunnelling with spoil displacement is characterized by the single-phase jacking of pipes with simultaneous displacement of the soil by means of a displacement and steering head, e.g. no system for removing … |
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In this variant, developed in Japan, the principle of soil removal and soil displacement are combined. A portion of the soil loosened by the cutting head is pressed and compacted through the exit opening into the annular space over the periphery of the shield skin against the borehole wall. This measure improves the soil parameters of the borehole wall, which influences the stability of the borehole and thus the pipe load and the skin friction [Stein96a]. … |
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This is a microtunnelling method also developed in Japan for use under groundwater in strongly permeable soils [FI-Okumu] [FI-IHI] that is utilized in Germany as the SDB system (SDB = Supporting Membrane Depot Box System) [Eulen01]. The main aim was to ensure … |
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Jun 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Jacking with uncoupling of the penetration resistance and skin friction The ENVILINER (types SH-253, SH-303, SH-305, SH-355, SH-408 and SH-456) is based on microtunnelling methods with auger spoil removal (Abschnitt 8.2) and was specially developed for jacking PVC pipes with screwed, glued or plug-in joint in the nominal size range DN/ID 150 to DN/ID 450 (Bild 8.7.3.1). In addition, this method can also be used with concrete and polymer concrete pipes [FI-Sanwaa]. (Image: ENVILINER method of type SH-253 for nominal pipe … |
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Jun 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Jacking with uncoupling of the penetration resistance and skin friction The RASA-UNICORN DH-Es [FI-Rasa] is a member of the group of microtunnelling methods with hydraulic spoil removal (Abschnitt 8.3) and is used for jacking PVC pipes in the nominal size range DN/ID 200 (machine type UNICORN DH-Es 200 (Bild 8.7.3.2) (Bild 8.7.3.2) (Bild 8.7.3.2) (Bild 8.7.3.2) (Bild 8.7.3.2) (Bild 8.7.3.2)) to DN/ID 300 (machine type UNICORN DH-Es 300) with jacking distances to 70 m (DH-Es 200) or 80 m (DH-Es 250 and 300). As already … |
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Jacking with uncoupling of the penetration resistance and skin friction has as its aim the jacking of rigid pipes with thinner walls as well as plastic (flexible) pipes. Using this technique when microtunnelling with auger spoil removal (Abschnitt 8.2), the jacking forces for overcoming the penetration resistance (which is difficult to calculate) are introduced through the spiral conveyor guide pipe. When microtunnelling with hydraulic spoil removal (… |
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The gripper method is a further development of the "jacking with uncoupling of the penetration resistance and skin friction" (Abschnitt 8.7.3) in which, additionally, the forces to be overcome in skin friction and those to be taken up by the jacking pipes are substantially reduced by breaking them down into equal force components (Bild 8.7) [Isele94]. A representative of this method is the LLB Method (LLB = Laying Pipes of Low Bearing Force) [FI-Kidoh] [… |
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(Image: Possibility of introducing the jacking force using the microtunnelling with auger spoil removal as an example [FI-Sanwaa] [Hiroh90]) In all jacking methods in which the jacking pipes are pressed in with the aid of a jacking station positioned in the starting shaft (e.g. microtunnelling and pipe jacking (Abschnitt 9.1)), the jacking force required is determined by the penetration resistance encountered by the boring head and the skin friction … |
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In these methods, jacking pipes [DINEN12889:2000] [ATVA125:1996] [Scher77a] [Stein85f] are jacked by pressing-in through the subsoil from a starting shaft to a target shaft with the aid of a jacking station or a main jacking station helped by intermediate jacking stations. Jacking in a straight or curved line path is made possible by means of a steerable shield machine positioned at the head of the first pipe. Operation and steering of the shield … |
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Sep 14, 2005 Trenchless Technology for Installation of Cables and Pipelines Shield machines with partial excavation by hand (hand shields) (Image: Open cowl shield with spiral conveyor for spoil removal and hydraulically extendable breast plate for gravel-sand soils without groundwater (external diameter 4280 mm) [FI-Eppin]) Natural support of the working face is always applicable when the existing subsoil is free of groundwater and the working face is a priori stable (working face without support) or is sufficiently supported by a self-forming earth wedge with a natural slope angle.… |
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Sep 14, 2005 Trenchless Technology for Installation of Cables and Pipelines Shield machines with partial excavation by hand (hand shields) With partial support, the surface of the working face is divided into sections and is either supported by means of natural partial support on bench plates (bench (plate) or platform shields) and/or by means of mechanical partial support using breast plates (Bild 9.2.1.1.2). With bench shields, this division into sections has the purpose of reducing the length of the earth wedge and the size of the surface area of the slope [Scher77a]. Depending on … |
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Sep 15, 2005 Trenchless Technology for Installation of Cables and Pipelines Shield machines with partial excavation by hand (hand shields) The use of hand shields is recommended wherever very short jacking distances make the use of mechanical excavation uneconomic due to the high initial investment for the complex machine technology. In trenchless installation they are mainly used for crossing of traffic lanes and jacking distances of less than 50 m as well as for excavating special cross sections such as rectangular or arched profiles with manaccessible cross sections (Abschnitt 3). |
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Hand shields are non-mechanised open shield machines in which the soil at the working face is loosened by hand using auxiliary tools (pickaxe, spades, shovels or pneumatic hammer) (Bild 9.2.1.1) (Bild 9.2.1.1) (Bild 9.2.1.1). The removal of the spoil is carried out with the aid of conveyor belts, transport carts or tracked conveying buckets (dump trucks) (Bild 9.2.1.1).
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Because of their relatively low costs and numerous possibilities for use in soil and rock free of groundwater, open shield machines with mechanical partial excavation enjoy a wide application for jacking lengths up to 1000 m [FI-Herreb]. Water retention measures (open water retention or groundwater lowering) are required when jacking in groundwater (Abschnitt 4.4) (Abschnitt 12.8.2). In the cases in which this is not possible or permissible, a closed … |
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