|
|
(Image: Microtunnelling with pneumatic spoil removal) An overview of components of a microtunnelling installation with pneumatic spoil removal is shown in (Bild 8.4.1.1.2) and the discussion in this respect will be found in Abschnitt 8.3.1.2. In place of the specific component parts for hydraulic spoil removal, the parts for pneumatic spoil removal are used here such as [FI-Hazem] :
|
|||||
|
|
Microtunnelling methods with pneumatic spoil removal are used in Europe by the following manufacturers: HAZEMAG & EPR [FI-Hazem] in the nominal size range DN/ID 400 to DN/ID 1200 in soils and rock with groundwater pressures to a maximum of 0.8 bar (8 m head of water above pipe crown), by HERRENKNECHT [FI-Herreb] in the nominal size range DN/ID 600 to DN/ID 1000 in groundwater-free "dry" soils and rock. Because of the method of operation, these microtunnelling … |
|||||
|
|
The HAZEMAG & EPR-P [FI-Hazem] and HERRENKNECHT AVP method [FI-Herreb] are German developments. The former machine can be used for microtunnelling with hydraulic spoil removal (MTB-S) as well as with pneumatic spoil removal (MTB-P) by simply re-equipping the conveying system. |
|||||
|
|
The excavation of the soil at the working face is carried out by the cutting head (Bild 8.4.1.2) with a 25 mm overcut with the addition of a drilling fluid for softening the spoil to a very soft to soft condition. The muddy soil enters the suction pipe through a hole in the dividing wall of the excavation chamber which is sealed by means of an elastomeric inflatable closing "valve" (Bild 8.4.1.2.1) (Bild 8.4.1.2.1) (Bild 8.4.1.2.1). The valve is opening … |
|||||
|
|
The DEINO TYPE is designed for jacking pipes in the nominal size range DN/ID 700 to DN/ID 1500 in soil and rock with the properties shown in Tabelle 8.4.1.2.2. (Table: Area of application of the DEINO TYPE [Sakai97]) The jacking distances depend on the nominal size of the jacking pipe and are up to 800 m. Curve radii of 30 m or more can be jacked (Tabelle 8.4.1.2.2). The minimum depth of cover should be ≥ OD of the cutting head according to manufacturer'… |
|||||
|
|
The Japanese DEINO TYPE [FI-Shin] jacking method (Bild 8.4.1.2) has been specially designed for long distance jacking with tight curves (Abschnitt 9.5). It consists of the boring and steering head with several trailing shield segments in which the necessary machinery for carrying out the pneumatic conveying is accommodated, too (Bild 8.4.1.2).
|
|||||
|
|
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 … |
|||||
|
|
||||||
|
|
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 … |
|||||
|
|
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 … |
|||||
|
|
(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) [… |
|||||
|
|
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].
|
|||||
|
|
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) |
|||||
|
|
(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 … |
|||||
|
|
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 … |
|||||
|
|
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 … |
|||||
|
|
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]. … |
|||||
|
|
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 … |
|||||
|
|
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 … |
|||||
|
|
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 … |
|||||
|
|
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 (… |
|||||
|
|
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] [… |
|||||
|
|
(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 … |
|||||
|
|
|
|||||
|
|
11094 search results:
