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Within the scope of inspection and also the acceptance of rehabilitated locally limited areas of damage in accessible sewers, e.g. cracks before and after sealing by means of injection (Abschnitt 5.2.2), it can make sense to carry out the testing only specially for the affected region. Testing equipment for this purpose is shown in Bild 4.5.1.5. It consists of a test chamber of steel elements that are provided with hollow rubber profiles on the outside … |
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As regards the testing of newly built or rehabilitated manholes and their pipe connections, EN 1610 [DINEN1610:1979], specifies that in maintaining the test pressure that results from filling the manhole to the surface, the water addition required within the test time of 30 minutes may not exceed 0.4 l/m2 of internal wetted surface area. If the manholes are tested together with the sewer section, then the permissible water addition is 0.2 l/m2 of … |
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The results of the leaktightness testing must be documented at site comprehensively and accurately in a test report as follows:
In order to ensure an optimal and economical further processing of the data, one can use electronic data processing in addition to the test record established at site. The test record must be created … |
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Until the introduction of EN 1610 [DINEN1610:1979] in the European Union, different criteria applied in the individual countries for the leaktightness testing of newly laid drains and sewers. A selection of these for the leaktightness testing with water is given in Tabelle 4.5.1.1.1. They formed one of the bases for the following investigations. Tabelle 4.5.1.8 compares the leaktightness criteria of an example of selected international standards in … |
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A possibility little discussed in Germany up to now for leaktightness testing of sewers is the infiltration measurement. This method is standardised in the USA in the ASTM Standard C 1091-90 [ASTMC109190] for gravity pipes of vitrified clay and in Great Britain independent of the materials. With this type of leaktightness testing, leaks are methodically sanctioned which contradicts the requirements of the EN 752 [DINEN752f] for watertight sewers. … |
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In order to determine the source of foreign water influx, illegal or incorrect connections (bad connections), in the separated sewers (Bild 4.5.1.10) (Bild 4.5.1.10) and limited also to leak localisation (Abschnitt 4.5.2) for sewers not lying in groundwater, the quick and cheap method of the smoke test or mist test can be used [Hochs96a] [FI-KIPP].
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Nov 19, 2004 According to EN 752 [DINEN752f] and ATV-A 139 [ATVA139b], sewers must be durable, functionally safe and leaktight. This means that substances may neither reach the groundwater nor may the groundwater be drained in order to prevent the damage effects connected with it and mentioned in Tabelle 2.9. The result of this for all operators of sewers is the duty not only to investigate newly installed and rehabilitated drains and sewers within the scope of … |
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(Image: Principle of an acoustic leak localisation with the correlation method with reference to [FI-Sewera] [Image: S&P GmbH]) Acoustic leak localising systems have been in successful use for years in the water supply sector. This is a simple method of investigation without the use of much equipment in which localising is achieved either by listening to the sewers for flow sounds using hydrophones [FI-Sewera] or with the correlation method [FI-Sewera] [… |
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In this group of methods, the conductance of (waste) water is utilised for localising leaks in drains and sewers. A process that has already been used for localising and quantifying leaks in sewers is the sewage probe AMS-4 [FI-seba] [Schub98] [Kramp98] [Kreut94]. The sewer to be tested is sealed off and flooded with water. According to the manufacturer, it is immaterial whether fresh water or backed up sewage is used, as it is only used as the electrical … |
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At present, methods based on thermography that are meant to provide an exact localising of leaks within the framework of internal or external inspection are in the development stage. In this, one assumes the fact that all bodies transmit long wavelength particles that are called the infrared region of the electromagnetic wave spectrum. The spectrum comprises wavelengths of 0.7 to 1000 μm. As all bodies act as emitters of long wave radiation and not … |
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Nov 22, 2004 The localising of leaks with the methods of leaktightness testing described in Abschnitt 4.5.1 is very time consuming if not problematical. In the methodical localisation of not optically recognisable leaks, it is necessary to begin with the section of the sewer method of leaktightness testing. By repeated halving of the respective pipe length with consequential repeated leaktightness testing, the leak can be limited to repeatedly smaller lengths. … |
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When relevant documentation regarding trade effluent, the leaktightness, the quality of the receiving waters as well as other effects on the environment is missing, then according to EN 752-5 [DINEN752-5:1997] the following investigations must be carried out: "The location of trade effluent sources shall be identified and the nature, quality, quantity and the potential environmental hazards reviewed". "The quality of all receiving water shall be determined … |
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The inspection report must be created on the basis of a section of the sewer. It must contain [ATVM143-2] :
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A sewer database opens up the possibility of storing and evaluating the information on the condition of the sewer, of the hydraulic dependencies and the changes in value of a sewer network. The necessary collection, acquisition and extension of the data require a large amount of effort and must be judged in comparison with the achievable application uses. According to this point of view, the operator must decide whether these conditions are suited … |
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(Image: Arrangement of the case and base data [ATVA145]) In accordance with ATV-A 145E [ATVA145], the structure of a sewer database should be carried out in steps depending on the desired application possibilities. In principle, a SDB can be divided into four file groups:
Each group receives the necessary basic data and the associated case data for its region so that the following … |
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Because of the large amount of work entailed, the creation of the master data decided upon is only carried out once and as comprehensively as possible in a prescribed format. When acquiring the case data, care must be exercised that an unambiguous allocation to the master data is achieved. The geographic data are determined on the basis of the selected geographic system, the basic data is taken from the official cartographic plans, the sewer plans, … |
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Feb 16, 2011 All the relevant facts of the measures undertaken for maintenance, inspection and rehabilitation of the drain and sewer system outside of buildings are documented as condition and operating data in the sewer database. They can be retrieved and output in the form of manhole and section reports. In addition, the damage acquired on videotape during optical inspection can be retrieved and viewed via a suitable interface. By means of the linkage of the … |
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Feb 16, 2011 Sewer network calculations can be carried out by means of linking the master data with the hydraulic data via an interface with an evaluation program. This can have the following aims:
When linked with the … |
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Feb 16, 2011 In order to evaluate the value, there is carried out the calculation of the plant valuation by means of suitable calculation programs, linking the master data with the cost data or, if necessary, including the condition data. This has the aim of discovering the reduction of value as well as the capital involved in the plant, and the interests that must be paid. Plant value includes, property and ground, buildings, operating plant, machines, plant … |
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Feb 16, 2011 Using a capable graphic system, the data of the sewer database can be used to present:
to various scales. In addition, with the linkage of the layout plans with digital municipal layout maps with street maps and building layouts, detailed
can be produced. The processing and alteration of existing data should … |
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Feb 16, 2011 The data in the sewer database can be sorted and output in the form of printed lists according to various criteria, either singly or in combination. Possible examples are:
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Feb 16, 2011 (Image: Structure of a sewer record to with reference to [ATVA145] [Image: S&P GmbH]) In order that the sewer database is suitable for the requirements and demands of the users, it is recommended that a modular structure be utilised. Furthermore, the possibility should exist of tying the data into a sewer or geographical information system (Bild 4.6.2.4.6). The linking with other databases, for instance with indirect introduction record as well as … |
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The numerous possibilities of application and the detailed information presented by the evaluation of the data material depend on the quantity and the variety of the input data. It must be considered that the usage of the information must be in a positive comparison with the effort expended in the acquisition and maintenance of the data material.
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The large amount and variety of different data (inspection data, inventory data) that is expected, require documentation with the aid of:
Under the aspect of co-ordinated and future-oriented rehabilitation and maintenance of sewers, the sewer database (SDB) presents and optimal working tool for documentation and updating of inventory data and inspection results. It offers, in alphanumerical form, the … |
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The aim of documenting inspection results must be to provide an accurate and comprehensive overview of the actual condition of the sewers or individual regions or of the damage that has been found in a clear manner in which the contents can be easily compared. In the following, the documentation will be explained in the form of an example of the optical internal inspection in accordance with ATV-M 143E Part 2 [ATVM143-2]. It comprises:
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