A manhole (even manhole , manhole , entry or inspection chamber is) a manhole structure which, merging is used according to the standard for changing direction, height bridging of different pipelines, review, maintenance and cleaning of pipelines. These manhole structures are divided into 2 different pipeline systems: mixed water, waste water and rain water. They are part of municipal sewage disposal . A mixed water system brings with it a shaft every 50 m. With the separation system (waste water and rain water (individually)) there are two manhole covers directly next to each other. But they are also the polygon point of the change in direction of a line, with the maximum angle of 100 gon (90 °). A shaft and the following in the flow direction pipeline is called attitude . Internal length: approx. 50 m and external length: approx. 100 m. According to ISYBAU, they have the same name. Inspection shafts usually consist of precast concrete parts , masonry , fiber cement , polymer concrete or plastic . A combination of different materials is possible.
Inspection shafts consist of different components:
- Manhole cover
- Support ring (AR-V) (non-shifting)
- Manhole neck (SH-M) (also cone )
A cone is a manhole ring (generally the top manhole ring) to taper the inspection manhole towards the top. The taper is asymmetrical, one side is vertical and crampons are embedded on this side. Usually the cone has a height of 60 cm, the top diameter is 625 mm, 800 mm or 1000 mm.
- optional components
- Cover plate (AP-M) (thickness 150 - 250 mm, depending on requirements) as an alternative to the cone for low shaft heights or unfavorable division of the components.
- Transition plate (UEP-M) (for manholes larger than 1200 mm and more than two meters above the canal base, usually at 1000 mm)
- Foot support rings (FAR-M) (thickness 250 mm)
- Manhole rings with crampons (SR-M) (according to DIN 1212 , e.g. type 1212-E or 1212-GS) or other entry aids such as a ladder or stirrup with plastic coating (according to DIN 19555 , made of steel (e.g. type A 400 S or B 300 S) or made of stainless steel (e.g. A 410 O or B 310 O)).
Manhole base with shaft bottom and Fließgerinne. (SU-M)
- Nominal size of the manhole base DN 1000
- up to pipeline DN 600 (circular profile)
- Nominal width of the manhole base DN 1200
- up to pipeline DN 800 (circular profile)
- Nominal width of the manhole base DN 1500
- up to pipeline DN 1000 (circular profile)
- Nominal size of the manhole base DN 2000 (outside of DIN 4034 and EN 1917 )
- up to pipe DN 1500 (circular profile)
- Nominal size of the manhole base DN 2500 (outside of DIN 4034 and EN 1917 )
- up to pipeline DN 1800 (circular profile)
- Nominal size of the manhole base DN 1000
- Manhole inlets or outlets
The channel in round manhole manholes with a diameter of 1.00–2.50 m is usually made with an extension in concrete, stoneware half-shells, plastic or clinker. However, concrete does not have a high resistance to sulfur and other pollutants, which is why a channel and berm made of concrete is usually dispensed with in sewage manholes . However, there are concrete additives that achieve a higher sulfate resistance. (SR-Zement) (formerly: HS-Zement)
In addition to the round accessible sewer manholes, there are also manual manholes, but these usually have an angular shape, which were previously built with conical sewer clinker bricks.
The inside diameter of the manhole for prefabricated manholes depends on the pipe diameter, the profiles, the number and the angle of connection of the connected sewer profiles.
Another type of construction are so-called tub shafts, which do not have a round cross-section, but rather a shape that is elongated in the direction of the duct.
Shafts (more likely shaft covers) are differentiated according to load classes, such as class D 400 and class F 900.
- A 15 → for green areas and traffic areas that can only be used by pedestrians and cyclists
- B 125 → for sidewalks, pedestrian zones and comparable areas, car parking areas and car parking decks; often for private sewers
- C 250 → for curb channel area (e.g. curb slot channels), parking spaces, hard shoulder stripes and the like
- D 400 → for road lanes (including pedestrian streets), hard shoulders on streets and parking areas that are approved for all types of road vehicles; is most commonly used.
- E 600 → for areas that are driven on with high wheel loads, e.g. B. Industrial and military facilities
- F 900 → for areas that are driven on with particularly high wheel loads, e.g. B. Air traffic areas and ports
Inspection shafts can also be assembled from different nominal widths with the help of transition plates. It is also possible to combine different materials and profiles, for example an angular masonry manhole base with a further structure of manhole rings and cones made of concrete.
- EN 124 (old DIN 1229) - attachments and covers for traffic areas
- EN 1917 - Manholes and inspection shafts made of concrete, steel fiber concrete and reinforced concrete
- DIN 4034 - precast concrete parts
- DIN 4051 - sewer clinker
- DIN 1211 and DIN 1212 - crampons
- DIN 19555 - stirrups
- DIN 28124 - Manhole closures for pressure vessels made of unalloyed steels
Structure in a sewer network
- Change of direction maximum 100 gon
- Angle specification of the inlets relative to the outlet with 0 gon, then the inlets follow in clockwise direction.
- Dietrich Richter, Manfred Heindel: Road and civil engineering . BG Teubner Verlag, 2008, ISBN 978-3-8351-0057-2 , p. 182 ff.