|
|
Of further importance for the steering of a microtunnelling or shield machine is the knowledge of its inclination and roll angles (Abschnitt 11.2). For the determination of inclination and roll angles of the microtunnelling … |
||||
|
|
The measurement of the distance travelled by the jacking or shield machine or by the boring and displacement head (jacking advance) is of primary importance for determining position. This can be carried out by means of:
|
||||
|
|
|||||
|
|
With this measurement system a passively illuminated (Bild 11.3.1.1) or self-illuminated target board (diode target board) is observed by the person carrying out the measurement or the equipment driver at predetermined jacking stations through the telescope in order to read off the target board coordinates (Bild 11.3.1.1).
|
||||
|
|
This measurement system corresponds in principle to the one with theodolite or laser theodolite with direct target board observation (Abschnitt 11.3.1.1). In this case, the picture of the target board is not seen directly by an observer but is recorded by a video camera that can be installed either in the target board itself (Bild 11.2.2.2) (Bild 11.3.1.2), near the target board (Bild 11.2.2.2) or in the ocular of the theodolite (Bild 11.3.1.2) and … |
||||
|
|
The combination of directional laser with active target board has found wide acceptance especially with microtunnelling and pipe jacking for a selection of manual, semi- or fully automatic steering methods [Fitzk94]. In this case, a laser beam that impinges on an active target board is used as an optical means of guidance (Abschnitt 11.2.2.2). One representative of this standard measurement system is the ELS (Electronic Laser System) (Tabelle 11.3.1.3) |
||||
|
|
|||||
|
|
Jul 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Measurements in the pipe string (without line of sight to the starting shaft) (Image: Measuring arrangement when using a theodolite for measuring the positional deviation of the shield machine [Borne83]) Static measurement with a theodolite is the oldest measurement method used in pipe jacking [Borne83] [Jacob96]. In order to acquire the position of the shield machine, it is necessary with each measurement procedure to measure and calculate the whole survey traverse and altitude transfer from the starting shaft up to the target … |
||||
|
|
Jul 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Measurement with onboard apparatus (dynamic survey traverse measurement) Representatives of the survey traverse measurement with onboard Servo Total Station include:
The … |
||||
|
|
Jul 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Measurement with onboard apparatus (dynamic survey traverse measurement) (Image: System overview of the NELS curve measuring system with reference to [FI-Herre98] [Image: S&P GmbH]) In place of an onboard Servo Total Station as well as the connection to survey prisms for survey traverse measurement, use can also be made of a gyroscope in connection with a directional laser. A representative of the measuring system "onboard gyroscope with directional laser" is the NELS curve measurement system (Bild 11.3.2.2.2) [FI-Herreb]. … |
||||
|
|
Jul 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Measurement with onboard apparatus (dynamic survey traverse measurement)
This automatic survey traverse measurement is a measurement whose quality is dependent, among others, on the accuracy of the direction transfer in the starting shaft, the accuracy of the measurements in the pipe string and the … |
||||
|
|
|||||
|
|
|||||
|
|
Jul 06, 2007 Trenchless Technology for Installation of Cables and Pipelines Measurement methods utilizing the previously described instruments
From DN/ID 1000, measurement systems with North seeking gyroscopes offer the possibility of determining the precise direction and position of the microtunnelling or shield machine in the man-accessible … |
||||
|
|
|||||
|
|
EN 12889 [DINEN12889:2000] and ATV-A 125E [ATVA125:1996] prescribe that the following measurement data should preferably be automatically acquired and displayed for monitoring the jacking:
|
||||
|
|
|||||
|
|
(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].
|
||||
|
|
Liner plates are understood to be bent (shaped) and possibly hot-dipped galvanized or plastic coated or epoxy resin coated steel plate elements that are prefabricated at the works in segments and are bolted together in-situ into shaft rings (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2) (Bild 12.5.2.2). In view of the wear at the construction site, corrosion protection is not normal … |
||||
|
|
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 … |
11094 search results:
