|
|
Aug 03, 2005
The location and the number of shafts are decisively influenced by the lay out of the sewer and the requirements of the trenchless construction method (e.g. realisable jacking length (Abschnitt 4.4), straight … |
|||
|
|
Jun 01, 2004
|
|||
|
|
Aug 04, 2005 The most widely used method in Germany for securing rectangular shafts, or shafts deviating from the circular, is that of using sheet planks or sheet piles because the construction companies have extensive experience in handling this type of lining and usually also possess the equipment required for it. The steel sheet planks or sheet piles with wall thicknesses between 3 mm and 8 mm are driven into the soil by means of ramming, vibration (shaking) … |
|||
|
|
Jun 01, 2004 An open sinking shaft is a shaft open at the bottom that is usually constructed in sections of in-cast concrete or of prefabricated reinforced concrete elements (Bild 6.4.3) (Bild 6.4.3) (Bild 6.4.3) on a manufacturing platform and that is sunk to its foundation level with simultaneous excavation of the core (Bild 3) (Bild 3) (Bild 3).
|
|||
|
|
Aug 03, 2005 (Image: Methods for securing shafts [Stein05a]) Decisive for the selection of a method of shaft construction, i.e. the measures for sinking and securing of a shaft, can be, for example [Stein05a] :
|
|||
|
|
Aug 04, 2005 When opening up the exit and entrance openings with jacking in soil that is free of groundwater, the main task is to avoid ground failure. In the cases in which a bentonite suspension is injected into the annular gap for reducing skin friction, or in which, despite the absence of groundwater, closed shields with fluid support or earth pressure support of the working face are used, care must be taken regarding sealing measures like in saturated subsoils (… |
|||
|
|
Jun 01, 2004 The gasketed opening seal consists of a single or double or duplex elastomeric seal (for high groundwater pressures) (Bild 6.5.2.1) (Bild 6.5.2.1) (Bild 6.5.2.1) (Bild 6.5.2.1) that is attached between the shaft wall and a correspondingly seal fixture. The seal fixture may use a steel fixed flange, an exit or entrance top hat or similar and, if necessary, additional intermediate rings as well as a bolted loose flange often consisting of several segments. … |
|||
|
|
Aug 04, 2005 Their purpose is to provide a transition, without damage, from the atmospheric pressure in the shaft to the groundwater pressure outside in the subsoil in order to permit unhindered exit and entry of the microtunnelling machine at the time of the opening of the shaft lining without additional measures. Pressure chambers always possess two locks and an integrated gasketed opening seal (Abschnitt 6.5.2.1) into which the microtunnelling machine enters. |
|||
|
|
Aug 04, 2005 (Image: Dewatering properties of different types of soils with water retention measures [Herth95]) The following measures are possible in order to prevent ground failure and groundwater inflows when creating and traversing the exit and entry openings [Stein05a] :
The simplest solutions, when technically possible are water retention measures for lowering the groundwater level [Rappe96] [DIN18305]. |
|||
|
|
Aug 04, 2005 Within the scope of microtunnelling and pilot pipe jacking a difference is made between the following phases of jacking [Konra01] :
|
|||
|
|
Jun 01, 2004 Shafts for drains and sewers consisting of jacking pipes have to correspond to EN 476 [DINEN476:1997] and ATVDVWK A 157E [ATVA157], respectively to the materialrelating shaft standards based on them (e.g. EN 1917 [DINEN1917:2004] and DIN V 4034-1 [Konra01] for shafts of precast concrete- and reinforced concrete elements). A manhole (DN/ID 1000) is usually built into the starting- or target shaft (double shell construction method, respectively shaft-… |
|||
|
|
Aug 03, 2005 |
|||
|
|
Jun 16, 2014 Article Herrenknecht AG With growing demand for raw materials, mines are applying increasing effort and expense to open up deep and difficult to access resources. With this in mind, the new Herrenknecht product portfolio of Raise Boring Rigs allows the optimal drilling of shafts with larger diametersat depths of up to 2,000 meters.
In the new and further development of Raise Boring Rigs, Herrenknecht draws on proven technologies and components as well as on extensive knowhow in the area of mechanized tunnelling technology.
|
|||
|
|
(Image: Installation of a manhole after completion of the jacking works - Starting shaft secured with the spray concrete construction method [Köln91]) Shafts are usually always necessary for trenchless installation of pipes and cables with unmanned, non steerable techniques (Abschnitt 5), unmanned, steerable soil displacement techniques (Abschnitt 6), pilot pipe jacking (Abschnitt 7.1), microtunnelling (Abschnitt 8.1) and pipe jacking (Abschnitt 9.1). |
|||
|
|
The locality and the number of shafts are greatly influenced by the lay out of the planned line to be jacked. For this reason, it is recommended when planning the line system to take into account right from the start … |
|||
|
|
(Image: Cross sectional shapes of starting and target shafts) The shape and dimensions of shafts should be planned and built under the aspect of minimising expected emissions and construction costs as well as work and health protection. Shafts in which work is carried out must have sufficient working space. The dimensions of the working space depend on the slope angle, lining, equipment, type of pipe and method of working [BGVC22] . At present, three … |
|||
|
|
Shaft construction is understood to be the method of sinking and securing of shafts [Olsha91]. Decisive for the selection of a method of shaft construction, i.e. the measures for sinking and securing of a shaft, can be, for example [Stein05a] :
|
|||
|
|
The simplest application form is presented by shafts with sloped walls (Bild 12.5.1) (Bild 12.5.1).
The inclination of the slope is suited to the subsoil (physical properties of the in-situ soil types, water conditions), the utilization of the adjoining surfaces (traffic paths, … |
|||
|
|
With standard horizontal linings to DIN 4124 [DIN4124:2002], the shaft walls are progressively lined during the excavation from the top to the bottom with horizontal, closely fitted wooden planks, sheet planks or similar and these are usually secured with vertical wale timbers and supported by bracing (Bild 12.5.2.1) (Bild 12.5.2.1) [Riege00b].
|
|||
|
|
With standard vertical lining to DIN 4124 [DIN4124:2002], wooden planks or sheet planks are progressively installed with the excavation or, in soft cohesive soil, are first driven vertically into the soil so that in all construction state, their points are at least 0.30 m in the soil. The earth or traffic loads acting on the vertical wooden planks or plank sheets are diverted into horizontal wale timbers or steel profiles that are installed in the … |
|||
|
|
||||
|
|
Non-removable (lost) linings (Bild 12.4) are understood in the case of trenchless installation to be covering, bracing and anchoring structures which are left partially or wholly in the subsoil after completion of the jacking or construction works. Thus, this method of lining offers the ability to use the structural shell as a network structure for operation and servicing in the form of a single or double shell lining (Abschnitt 12.2). The disadvantages … |
|||
|
|
||||
|
|
In closed sinking shafts, a massive pressure retaining cover with the side cutters forms a working chamber open to the bottom through which the water for sinking is forced out by means of compressed air. Air locks and shaft pipes make the working chamber accessible and the excavation base open for loosening and conveying the soil (Abschnitt 9.2.1.2.3) [Linge97]. This form of sinking shaft [Linge97] [Breck84] [Niema70] is relatively seldom used in trenchless … |
|||
|
|
|
148 search results:
