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Nov 19, 2004 (Image: Universal test figure T05/DIN 25 435 Part 4 [DIN25435-4]) As the above paragraphs have shown, the most varied systems of sewer inspection for all nominal sizes usual in sewer systems are available today. The requirements to be fulfilled for their use in Germany are formulated in [ATVM143-2] and the most important of them will be mentioned in more detail below:
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Nov 19, 2004 The oldest and simplest method of gaining an overview of the inner condition of straight laid and non-man-accessible sewers is direct viewing, if necessary, with the aid of sufficient lighting. For the sake of simplicity, use is made of sewer mirroring [Gürsc21]. In this method, a mirror is held at an angle of 45° at the end of the section of the sewer in such manner that an uninterrupted view is possible, whereby the light shines from the next … |
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Nov 19, 2004 The foremost technology in internal inspection is the optical condition acquisition. In Germany this is regulated by the ATV-M 143E Part 2 in [ATVM143-2], which will be referred to below. Depending on the methods used, the following can be acquired and qualitatively evaluated (Abschnitt 2.1) :
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Nov 19, 2004 (Image: Depiction of the principle of the inverted siphon measuring system with reference to [FI-KARO] [Image: S&P GmbH]) Deposits (Abschnitt 2.3.2.1) belong to the damage group of obstacles. They are presently acquired, together with incrustation, projecting flow obstacles and root ingress (Tabelle 2.9) within the scope of optical inspection and estimated as regards their effect on the cross sectional reduction as a percentage. The height of the deposits … |
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Nov 19, 2004 Inclinometers, also called gradient measurement instruments, are utilised in combination with the sewer TV inspection for determining the gradient of the individual pipes or the section of the sewer (Abschnitt 4.3.2.1). The core piece of such an instrument is generally a gravity sensor with a control loop for torque compensation [Stein89g]. The measurement signal is a direct current, which is proportional to the sense of the gradient of inclination … |
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Nov 19, 2004 (Image: Principle of the pressure measuring hose levelling device with reference to [Colli83] [Image: S&P GmbH]) The pressure measuring hose levelling instrument was developed especially for determining the vertical position (gradient, deflection, displacement) of non-man-accessible pipelines [Colli83] [NN86d]. A hose end is connected to a fixed level device containing a free fluid level as reference height. At the other end of the hose there is situated … |
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Feb 16, 2011 (Image: Measuring arrangement for determining the directional deviation by means of laser and hole plate [NN86d]) The construction laser used for pipe laying can also be used to measure the position of existing straight drains and sewers in both the horizontal and vertical directions. For this purpose, the laser is positioned at the end of a section of the sewer, e.g. in an access manhole, and is first calibrated by means of a control board situated … |
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Nov 19, 2004 Positional deviations in sewers can occur due to numerous causes (Abschnitt 2.4.1) and their recognition presents a condition for the evaluation of the hydraulic capabilities as well as for the selection of a suitable rehabilitation procedure. In accessible sewers, the measurement of the horizontal and vertical positional deviations is carried out by means of well-known engineering measuring methods, e.g. by means of the theodolite. In non-man-accessible … |
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Nov 19, 2004 Rehabilitation and Maintenance of Drains and Sewers Profile Measurement (Displacement, Deformation, Internal Corrosion and Wear) Calibration measuring apparatus are pulled through the pipe or are moved forwards under the pressure of the conveying medium and make possible, by means of spring contacts evenly distributed around the circumference, the acquisition of ovalities, buckling, alterations of wall thicknesses, welding beads, deposits, etc. For flexible pipes, however, this is valid only on the assumption of a vertically symmetrical and elliptical deformation figure in … |
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Feb 16, 2011 Rehabilitation and Maintenance of Drains and Sewers Profile Measurement (Displacement, Deformation, Internal Corrosion and Wear) Optical-electrical displacement measuring devices that are combined with a sewer TV camera are based mainly on the split-beam method. In this method, the pipe to be measured is illuminated not by means of points, but by a special light curtain (sheet) light that is created either with a corresponding optic or by means of a rotating mirror. The light reflected by the object surface is taken up by a receiver optic displaced in the direction of the … |
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Feb 16, 2011 Rehabilitation and Maintenance of Drains and Sewers Profile Measurement (Displacement, Deformation, Internal Corrosion and Wear) Powerful systems for determining the cross-sectional figure use laser measuring devices in combination with a video camera [NN95g] (Abschnitt 4.3.2.1) (Bild 4.3.2.2.3.3) (Bild 4.3.2.2.3.3). For measuring the pipe deformation, the measuring head positions itself automatically normal to the pipe wall and senses this in steps selected by the user by means of a laser distance sensor. The scatter beams reflected from the pipe wall are bundled by an optical … |
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Nov 19, 2004 Rehabilitation and Maintenance of Drains and Sewers Profile Measurement (Displacement, Deformation, Internal Corrosion and Wear) Sonar scanners have up to now only been used as extensions to the laser technology in order to make measurements in partly filled sewers possible (Abschnitt 4.3.2.3) [Campb95]. |
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Nov 19, 2004 (Image: 3D Laser Scan System: Laser-Scanner [FI-Buchm]) Although change of shape of flexible pipes (Abschnitt 2.7.1), deformation of cracked rigid pipes (Abschnitt 2.8.6) cross sectional measurements and internal corrosion associated with this (Abschnitt 2.6.3.2) and mechanical wear (Abschnitt 2.5) of sewers can be recognised through inspection by sewer TV cameras, or while walking through the sewer, quantitative information is only possible with … |
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Nov 19, 2004 (Image: Principle sketch of an "Impulse Echo Radar" with reference to [Lenz97] [Image: S&P GmbH]) Based on investigations carried out throughout the world, it has been determined that the exploration of the embedment by means of geophysical methods is basically possible but that there is a need for further development. One way to a solution is offered by the transfer of the so-called geophysical borehole measuring methods (e.g. gamma sensors, gamma-… |
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Nov 19, 2004
A fully new concept for the acquisition and description of the pipe-soil system from the … |
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Nov 19, 2004 Soil Exploration |
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Nov 19, 2004 There are many methods, instructions and numerous testing devices for testing accessible concrete and reinforced concrete sewers [NN86i] [ACI201] [Augus84] [Kuhne85] [Rybic79]. A review of the most important evaluation values, testing methods and aids is provided in Tabelle 4.3.2.2.5. Further information on testing methods with reference to the various testing aims can be found in [Larjo80] [Grube90] [Pohl69] [Bisle88]. (Table: Possible tests of concrete … |
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Nov 19, 2004 The results of optical inspections (Abschnitt 4.3.2.1) are often not sufficient to describe the condition of the sewers comprehensively and to provide satisfactory answers to questions of damage as well as type and extent of rehabilitation measures. In order carry out technically and economically based rehabilitation measures it may be necessary to carry out qualitative as well as quantitative determination of the actual condition (Abschnitt 4.2). |
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Jan 01, 1900 The methods presented below also deal with new developments that have not yet been used in practice. In all cases, an attempt is made, with the help of simultaneously utilised sensors to obtain different information on the actual condition of the respective sewers and, in some cases, of their bedding.
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Nov 19, 2004 The (KARO system) sewer robot has been conceived primarily for the inspection of concrete and vitrified clay sewers DN 200 to DN 500 and with a length of up to 400 m (Bild 4.3.2.3.1) (Bild 4.3.2.3.1) (Bild 4.3.2.3.1) [Kuntz95]. Besides a high resolution TV technology, the modular system concept consists of various sensors, especially optical, ultrasonic and microwave sensors that are in a position to detect the type, position and extent of damage … |
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Nov 19, 2004 A newly developed measuring system combining laser and ultrasonic measurement has been developed within the scope of the PIRAT project (Pipe Inspection Rapid Assessment Technique) by CSIRO, Australian and Melbourne Water [Campb95]. In this technique, the inner geometry of the sewers (including damage) is measured and then the data are analysed, identified and classified with the aid of modern computer methods. Depending on the level of the water, … |
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Nov 19, 2004 Also meant for internal inspection is the SSET system (Sewer System Evaluation Technology) being developed [FI-TOA] by TOA Grout Corp. & TGS Comp. in Japan. A combination of video inspection, scan and centrifugal techniques is meant to make the acquisition of the internal pipe surface possible in the form of a coating figure of the complete section of the sewer. Damage is identified and described by a colour and longitudinal horizontal and vertical … |
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Nov 19, 2004 (Image: Non-destructive hammer test with the Sonomolch with reference to [Kling94] [Image: S&P GmbH]) Acoustic methods can be used in order to discover non-visible damage. Besides information on corrosion on the external wall and bedding errors, measurements of the wall thickness as well as the course, position and depth of cracks are possible. A further aim of acoustic sewer inspection is the detection of errors in the operating condition with filled … |
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Nov 19, 2004 The methods presented below also deal with new developments that have not yet been used in practice. In all cases, an attempt is made, with the help of simultaneously utilised sensors to obtain different information on the actual condition of the respective sewers and, in some cases, of their bedding.
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Nov 19, 2004 Internal inspection includes all measures for determining and evaluating the actual condition of drains and sewers, manholes and the embedment or the immediate surrounding soil (Abschnitt 4.3.1.2) from inside. One distinguishes in this between the qualitative and the quantitative condition acquisition (Bild 4.3). Which of the methods and processes are to be used in the particular case under consideration, depends primarily on the nature of the inspection … |
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