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May 12, 2020 NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) Below are the diagrams for determining the pit length for PE pipes (SDR 33, 26, 21 and 17). (Image: Required insertion pit length lG for PE pipes SDR 33 (SN 2) pulled into a host pipe (clearance Δh / dL,a) [DWA-M 143-2 draft]) (Image: Required insertion pit length lG for PE pipes SDR 26 (SN 4) pulled into a host pipe (clearance Δh / dL,a) [DWA-M 143-2 draft]) (Image: Required insertion pit length lG for PE pipes SDR 21 (SN 8) pulled into a host pipe (… |
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May 12, 2020 NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) If the insertion pit is excavated along its entire length, pipes can be pulled in two directions. (Image: Insertion pit for the pulling in of two pipelines) |
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May 12, 2020 NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) The maximum strain of σ = 21 N/mm2 (Short Term) applies to PE pipes before buckling damage occurs, which is limited to (γ = 1.4) max σ ≅ 15 N/mm2 during installation. This strain includes the short-term modulus Eσ=15 = 500 N/mm2 and the elongation max ε = 3 % (DVS 2205-1 guideline). In order to prevent pipe buckling during the pulling in procedure, the radius of curvature is to be determined as per equation 11: Equation 11: (Formula: Krümmungsradius … |
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May 12, 2020 AE-08 Replacement: Pulling-In the Pipe String during the Pipe Bursting Process NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) To the max. RKbelongs the maximum allowable strain εK, with: Equation 12: (Formula: die maximal zulässige Dehnung εK) Due to the buckling danger, the strain max σKmust be reduced accordingly (see table on the next page). The associated modulus of elasticity can be approximated by interpolation: Equation 13: (Formula: E-Modul) (Table: Equation variables) |
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May 12, 2020 AE-08 Replacement: Pulling-In the Pipe String during the Pipe Bursting Process NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) In addition, the variability of stresses and thus the effective modulus of elasticity Em [N/mm2] of the pipe over the pit length lG , and the pipe diameter are taken into account as follows: Equation 14: (Formula: E Modul Em N mm2) (Formula: a von EModul Em Gleichung) If the pulling in of the pipeline takes place in temperatures other than 70 °F (20 ° C), the pit length can be corrected as follows: Equation 15: (Formula: Ermittlung des maximalen … |
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May 12, 2020 AE-08 Replacement: Pulling-In the Pipe String during the Pipe Bursting Process NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) With a longer interruption of the insertion process, the pipe in the insertion pit must be secured so that the maximum allowable bending radii (radii of curvature) are not exceeded. |
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May 12, 2020 NA-08 - Replacement: Pulling-In the Pipe String during the Pipe Bursting Process (Demo) Congratulations! You have successfully finished this module. Next you will have the opportunity to review the newly acquired knowledge with an interactive questionnaire. You can still navigate back to any point in the lessons if you wish to review a specific point or subject. Stay curious! |
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May 12, 2020 This module focuses on the parameters that must be considered when pulling in the pipe string for gas, water and wastewater pipelines. In addition to a basic description of the replacement procedure, the importance of tensile forces, bending radii, and the dimensioning of the excavation pit is therefore the focus of attention. After completing this module, you will have a sound knowledge of:
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Feb 16, 2011 (Image: Cutting head modified for "pipe eating" [FI-Solta]) In this replacement process, also known as pipe replacing or pipe eating, the defective, non-man-accessible sewer or pipeline is run down by means of an unmanned pipe jacking technique < DN 1200 (Abschnitt 1.3), destroyed and removed, and at the same time the new sewer or pipeline with the same or larger nominal size is laid in the same pipe course [Stein88a] [Möhri88]. Depending on the process, … |
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Pipe replacement with the introduction of dynamic forces was developed by the British Gas Corporation, England [FI-Britia] for the gas sector (European Patent No. 0053480) (Bild 5.4.3.4.2.1) and this was later adapted for the sewage sector. Based on this development, similar processes and machine developments have been marketed internationally and also in the Federal Republic of Germany [FI-Ryan] [FI-DIGA] [FI-Tracta] [FI-Terrab] [FI-Broch] so that … |
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Hydraulic pipe bursting has been used in the Federal Republic of Germany in the past few years, for instance, under the designation KM- Berstlining [FI-KMG] (licensed under the patented … |
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Advantages of pipe bursting:
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Nov 24, 2004 (Image: Depiction of the principle of the pipe bursting process (dynamic bursting process in combination with short pipes) [FI-Tracta]) The basic idea behind pipe bursting, developed in the 80's of the 20th Century, is to pull a bursting body with a winch cable or a tension rod through the sewer that has been taken out of service and to thus destroy the pipe walling from the inside and to force it into the surrounding soil. A new sewer with the same … |
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Nov 24, 2004
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Jun 24, 2005 |
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With replacement in the same run of the pipe by the trenchless method, pipe eating and exchanging the old sewer occurs pipe, e.g. without excavating an open trench. With this method the most important processes are:
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(Image: Overview of replacement processes) Under replacement, there is understood, according to EN 752-5 [DINEN752-5:1997], the construction of a new drain or sewer, on or off the line of an existing drain or sewer, the function of the new drain or sewer incorporating that of the old. The replacement is always carried out at least in section lengths of the sewer using (Bild 5.4) :
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(Image: Sequence of operations work flow for pipe bursting) |
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(Image: Condition acquisition of a sewer via CCTV-inspection) (Image: Maintaining the drainage capability) (Image: Exposing a lateral connection using the open cut method as part of the bursting process) Pre-construction survey: The pre-construction survey includes a walkthrough at ground level of the pipeline sections to be replaced, to, determine the location of existing pipelines and utilities in the surrounding area, as well as acquiring a visual … |
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Pipe cleaning, and removal of obstructions: Pipeline cleaning is not a required process as long as the pulling-in of the winch cable or the pulling rods is possible. If there are any obstructions preventing equipment access, e.g. pipe collapse, positional deviations, roots, etc., the pipeline must be cleared of such obstacles first. Preparation of the manholes: The manhole invert and connection areas must be prepared or modified in such a way that the … |
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(Image: Documentation) Upon arrival at the construction site, the pipes are to be inspected for defects and damages. In addition, the delivery papers must be checked in order to ensure that the product corresponds with the original order details. These checks must be documented as part of the quality assurance procedure. (Image: HDPE discrete long pipes DA 20 in (500 mm)) |
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(Image: Bursting head with a directional guide) Pipe bursting procedure: Installation of the new pipeline while considerating permissible tensile forces and bending radii. There must be an overlap between the external diameter of the expander head and that of the new pipeline in order to reduce the frictional forces during the pulling through procedure. In other words, the expander head will have a larger diameter than the new pipe that will be pulled … |
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(Image: Realisation of pipe bursting from the insertion manhole to the reception manhole) Manhole to manhole: Utilization of segmental pipes and bursting equipment suited to the size of the manhole structure. (Image: Realisation of pipe bursting from the insertion manhole to the reception pit) Manhole to pit: Utilization of segmental pipes and bursting equipment suited to the size of the manhole structure. Installation of the pulling equipment in the … |
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(Image: Realisation of pipe bursting from the insertion pit to the reception manhole) Insertion pit to manhole: Installation of the pulling equipment in the manhole or above it. Either the segmental or the continuous pipeline, together with the bursting unit, are introduced through the insertion pit. The size of the bursting unit is accordingly dimensioned as to allow for its removal from the target manhole. (Image: Realisation of pipe bursting from … |
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(Image: Connection of the new pipeline to the manhole) Connection of the new pipeline to the manhole: The connection between the new pipeline and the manhole structure must be properly sealed so that water cannot infiltrate the surrounding soil. A leakt-ight joint must be placed between the manhole wall and the new pipe. The manhole channel and benching must be fitted to the new pipeline. (Image: Re-connection of a lateral to the new pipeline with the … |
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