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May 18, 2020 |
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May 18, 2020 |
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May 18, 2020
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May 18, 2020 (Image: Distribution of damages in pipe jacking in Germany (source: IFB, Hanover 1993)) |
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The calculation and continuous monitoring of the jacking process is an important tool for the prevention of damages in order to secure:
(Image: Crack formation as a consequence of splitting tensile stresses due to unbalanced load introduction into the pipe faces) |
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May 18, 2020 |
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May 18, 2020 |
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May 18, 2020 Today, the installation of gas, water and wastewater pipelines is still predominantly carried out using open trenches. In view of the numerous disadvantages associated with this method, it is imperative that trenchless pipeline construction be considered much more strongly in the future than it has been to date, as an alternative in the planning and construction of sewers and pipelines.
This module deals in detail with the numerous different types of shield machines, obstacle removal and possible errors in pipe jacking and their consequences.
After completing this module, you will have a sound knowledge of:
- limitations of the use of shield machines and
- errors and consequences of damage during pipe jacking.
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Water: From a chemical point of view, water (H2O) is a compound consisting of two hydrogen atoms (H) and one oxygen atom (O). As per DIN 4049-1, the term “water” is a collective name for all naturally occurring kinds of water, thus including substances that have dissolved, emulsified and suspended in it including microorganisms [DIN4049-1] (Image: Global distribution of water) |
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According to DIN 4049-1, the hydrologic cycle is the permanent changing of water in its state and location, with its main components being:
[DIN4049-1] (Video: Global hydrologic cycle) |
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The water circulates from one reservoir to the next, whereas the seas (oceans and their semi-enclosed and adjacent seas) that cover about 70 % of the Earth’s surface represent the largest water reservoir. Depending on the water reservoirs involved, we distinguish between three different hydrologic cycles:
(Video: The three different hydrologic cycles) |
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The hydrologic balance equation (in general also called water inventory or water budget equation) is a quantitative description of the natural hydrologic cycle, i.e. the interrelation between the components and environmental compartments of water (hydrosphere), soil (pe-dosphere) or air (Earth’s atmosphere). The components are:
(Image: Basic hydrologic balance equation) |
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The regional hydrologic cycle is in a small way also influenced by the “urban hydrologic cycle” that is shaped by man. The mere development of urbanisation (the spread of the urban lifestyle) has a massive influence on the water balance and results in both quantitative and qualitative changes of the units to be balanced in the catchment area under observation. According to Klinger, the hydrologic balance equation for urban areas is described as:
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(Image: Attention!) The proper functionality and leak-tightness of the drain and sewer system has a massive impact on the hydrologic cycle in urban areas, and thus also on both the quantity and quality of groundwater as a resource. Combined with the effects of the global climate change (global warming, climatic shifts), this fact becomes a national challenge. What is important in this context is to realise that due to the very distinct local and environmental … |
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Congratulations! You have successfully finished the first part of the lesson. The lesson continues in the form of a script. Please take all further information from the following script “Hydrologic cycle”. Stay curious! |
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Aug 06, 2015 This module provides an essential basic understanding of the global hydrologic cycle along with the quantitative description of the natural and urban hydrological cycle through the hydrologic balance equation. After completing this module, you will have knowledge regarding:
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