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The soil body (initial + main backfill) located above the pipe generates vertical loads (static earth load). Under certain conditions, these loads can be reduced. If these conditions apply, we speak of the "silo effect". When applying the silo theory, the following are of influence:
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What needs to be done to verify the load bearing system?
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What needs to be done to verify the load bearing system?
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The vertical loads acting on the pipe must be transferred to the ground. This transfer is performed by the pipe support. The pipe support is described by the support angle 2 α (alpha). The larger the support angle 2α, the better the support. The illustration shows a support angle with 2 α = 90, i.e. α = 45. In addition to the size of the support angle, another important quality feature of the support is the uniformity or homogeneity of the compaction … |
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The vertical loads acting on the pipe must be transferred to the ground. This transfer is performed by the pipe support. The pipe support is described by the support angle 2 α (alpha). The larger the support angle 2α, the better the support. The illustration shows a support angle with 2 α = 90, i.e. α = 45. In addition to the size of the support angle, another important quality feature of the support is the uniformity or homogeneity of the compaction … |
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The distribution of the vertical load at the height of the pipe crown depends on both the stiffness of the pipe and the stiffness of the of lateral soil next to the pipe (side fill). Rigid pipes (vitrified clay pipes, concrete pipes) deform only insignificantly, so that even with well-compacted side fill, the pipe is usually stiffer than the soil. This leads to a load concentration on the pipe, because the lateral soil (side fill) is relieved. The … |
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The distribution of the vertical load at the height of the pipe crown depends on both the stiffness of the pipe and the stiffness of the of lateral soil next to the pipe (side fill). Rigid pipes (vitrified clay pipes, concrete pipes) deform only insignificantly, so that even with well-compacted side fill, the pipe is usually stiffer than the soil. This leads to a load concentration on the pipe, because the lateral soil (side fill) is relieved. The … |
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Aug 16, 2022 Article Dipl.-Ing. Christoph Bennerscheidt DN 1000 power plant pipeline
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Sep 20, 2017 Article vonRoll hydro (suisse) ag Lake Geneva offers heating energy for its local communities. By means of heat pumps it can be put to good use. The pipelines installed for transporting the water from the lake consist of ductile iron pipe systems which are perfect for the job: they are corrosion-protected inside and out and their large hydraulic cross-section means that operational costs are kept low. Electrically insulating thrust resistance systems prevent the risk of damage due to stray currents and they are easy and safe to install. In short, the ductile iron pipe system meets all the conditions for transporting low-temperature district heating.
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Jun 20, 2019 News Lauren Slepian Water and Sewer Line Protection Program Saves Philadelphia Homeowners $1 Million in First Six MonthsPhiladelphia officials on Wednesday joined American Water Resources (AWR) representatives to announce that a new water and sewer line protection partnership has already saved Philadelphia homeowners more than $1 million in the first six months of enrollment.
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Jun 21, 2019 News Carolin Neudeck Algae farming is widespread in China. The macroalgae Laminaria is mainly used for food in China but its bioactive ingredients are also used, for example, in cosmetics, dietary supplements or as an additive to animal food. The industrial processing of Laminaria produces wastewater with a salinity of around 20 percent.
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Mar 25, 2019 Sewer systems are either permanently or temporarily subject to different physical, chemical, biochemical and biological forms of stress. Depending on the
these stresses can more or less rapidly result in different structural, operational, environmentally … |
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Mar 25, 2019 |
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Mar 25, 2019 In the following, the types of defects in drains and sewers that can be detected during a visual internal inspection as well as their possible causes and consequences will be described in accordance with EN 13508-2 [ [EN13508-2:2011]], ATV-DVWK-M 143-1 [ [ATVM143-1:2004]] and DWA-M 149-2 [ [DWAM149-2:2013]]. In this context, EN 13508-2 [ [EN13508-2:2011]] distinguishes between a total of four main codes:
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Mar 25, 2019 According to EN 13508-2 [ [EN13508-2:2011]], deformation is defined as “the cross-sectional shape of the pipeline has been deformed from its original shape”. For this type of defect, the client will define whether this code must only be used for flexible pipes or for pipes made of all kinds of material. Pipes are defined to be flexible when their deformation has essential effects on the distribution of loads and pressure, as the soil is a component … |
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Mar 25, 2019 According to the definitions mentioned above, the classification as either flexible or rigid pipe always has to be made taking the soil consistency into account. Thus, it is rather a categorisation of the entire system composed of the stiffness of the pipe and soil consistency than a mere assessment of the stiffness of the pipe. In order to ensure the load transfer as a pipe-soil-system, the stiffness of the pipe has to provide for both a consistent … |
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Mar 25, 2019 Possible causes of defect Deformations in the sense of a defect can be caused by:
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Mar 25, 2019 In his dissertation [ [Bosse97]], for an assessment of the cross-sectional shapes that were recorded at individual monitoring stations in the sewer by means of the measurement systems explained in section 4.1.3.1.3 and section 4.1.3.1.4 (both in progress), Bosseler suggests a circular ring with a negligibly small wall thickness d as the undeformed initial system. In the plane, each point P on the circumference of the circle has two degrees of freedom … |
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Apr 01, 2019 On the basis of the approximated bending line and by means of the coefficients of the Fourier series, approximation possibilities for interpretation are provided with regard to the interior bending work Wi of the deformed linear-elastic circular ring (Remember: work is equal to force times distance). Using the series approach (Equation 2‑1), and in accordance with Bosseler [ [Bosse97]], this can be calculated as follows: (Formula: Bending approach … |
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Mar 25, 2019 In addition to the analysis of individual control cross sections N, an assessment of the course of the individual amplitudes and phase angles across the sewer section length is also of interest. For that purpose, these parameters can be applied subject to the line length and linearly interpolated between the measuring points. Examples for such courses of deformation taken from the research of Bosseler [ [Bosse97]] are illustrated in Image 2‑25 and |
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Mar 25, 2019 Thin-walled pipes fail under bending due to buckling behaviour [ [Seide61]] [ [Axelr1983b]], which could also be proven in test series [ [Spenc79]] [ [Brazi27]]. A theoretical introduction and literature survey can be found in Axelrad [ [Axelr80]]. In the pre-buckling deformation condition, a non-negligible deformation of the pipe cross-section (ovalization) occurs in conjunction with the elastic distortion. Often, in the past, this non-linear bending … |
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Mar 25, 2019 As described in (Vertical cracks (longitudinal cracks)), at present, there are only very sketchy suggestions with regard to the classification of deformations for flexible pipes. These are generally limited to the parameter of the vertical deformation dv and consider deformations that are larger than planned in the structural design as descriptions of damage. In (Geometrical cross sectional analysis), the related types of misinterpretation, which … |
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Mar 25, 2019 According to EN 13508-2 [ [EN13508-2:2011]], the description of a defect fissure (crack) mostly occurs for rigid pipes. The formation of fissures is characterised subject to the nature of the fissures and their orientation, whereby it is distinguished between the following types of fissures that can be the precursors for pipe fractures and the subsequent collapse of a sewer ( (Break / Collapse (BAC))):
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Mar 25, 2019 The consequences of cracks occurring in sewers are essentially influenced by:
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