CN206693363U - Assembled plastics municipal drainage inspection shaft - Google Patents

Abstract

The utility model relates to an assembled plastics municipal drainage inspection shaft belongs to the drainage engineering field. The inspection well structure size of the existing standard diagram is taken as the basis, and the standard flow groove, workbench and well descending maintenance requirements are met. The plastic-concrete composite well mainly comprises a foundation, a well bottom, a well chamber, a cover plate, a well shaft, a well mouth and a well cover, wherein the well bottom, the well chamber, the cover plate, the well shaft and the well mouth are made of plastic components and are combined on site, a reinforced concrete frame is arranged around a plastic well body to serve as a bearing structure, ground load and soil pressure around the well are borne by reinforced concrete, and a plastic and reinforced concrete composite structure is formed. When the frame concrete is poured, the plastic well body is used as a template, formwork supporting and formwork removing are not needed, and the material and labor for formwork supporting and formwork removing are saved. The complex procedures of bricking of municipal drainage inspection wells or concrete pouring by supporting a formwork in the prior art are omitted, the construction speed is high, and the quality is easy to control.

Description

Prefabricated plastic municipal drainage inspection well

technical field

The utility model relates to an assembled plastic municipal drainage inspection well, which belongs to the field of drainage engineering, in particular to a plastic drainage inspection well used under municipal roads.

Background technique

Urban drainage is divided into rainwater and sewage. The drainage system is divided into diversion system and combined system. Most cities adopt the diversion system, that is, rainwater and sewage are discharged separately. Units or residential areas along urban roads generally have organized drainage, collecting and discharging rainwater and sewage to drainage pipes under urban roads, commonly known as municipal drainage pipes. Rainwater and sewage are discharged to water bodies or sewage treatment plants through municipal drainage pipes. Inspection wells shall be set at regular intervals of municipal drainage pipes, where pipes turn, and where branch pipes are connected. Municipal drainage pipes are characterized by larger pipe diameters and larger manholes used. "Code for Design of Outdoor Drainage" GB50014-2006 stipulates the height of the well chamber of the inspection well, the setting of the flow channel, and the radius of the flow channel of the inspection well at the turning. When designing drainage pipelines, designers use the national standard drawing "Drainage Inspection Well" 02S515, or "Municipal Drainage Pipeline Engineering and Auxiliary Facilities" 06MS201, the latter is the revised and bound version of the former. Municipal drainage inspection wells are divided into circular, rectangular, fan-shaped, etc. according to the diameter of the pipe. There are four types of circular inspection wells with diameters of 700mm, 1000mm, 1250, and 1500mm. They are suitable for pipes with a diameter of less than or equal to 1000mm. The inspection wells with larger diameters are rectangular, and the inspection wells at the corners of large diameter pipes are fan-shaped. There is a trough in the drainage inspection well to reduce turbulent flow and increase the flow rate. It is also equipped with a workbench for maintenance personnel to go down the well for maintenance. The height of the well chamber is also required to ensure sufficient space for downhole operations.

The plastic drainage inspection wells of the prior art are all relatively small, and can only be applied to drainage pipes inside residential quarters and enterprises and institutions. "Technical Regulations for the Application of Plastic Drainage Inspection Wells" CJJ209T-2013 stipulates that the regulations "applicable to drainage inspection wells with a diameter of no more than 1000mm and a buried depth of no more than 6m in newly built, expanded and rebuilt buried drainage systems"; Inspection wells" 08SS523 clearly apply to "plastic drainage inspection wells with buried plastic drainage pipes with an outer diameter of no more than 800mm and a buried depth of no more than 6m within the scope of building communities (residential areas, public building areas, factory areas, etc.)" . According to the structural requirements of municipal drainage inspection wells, the plastic inspection wells of the prior art cannot be used in municipal drainage pipeline projects. The prior art "Municipal Drainage Plastic Inspection Well" patent number CN201520385429.7 and "Large Plastic Inspection Well" patent number CN201210519421.6 use reinforcing ribs to improve the strength of the inspection well. For the necessary structures such as trough and workbench, the designer will not be able to adopt them because they do not meet the specification requirements. The diameter of the municipal drainage pipe is larger, and the corresponding inspection well is also larger. For example, for a four-way inspection well with an outlet pipe diameter of 1500mm, the well chamber size is 3.3m long and 2.48m wide, and the well chamber height for rainwater pipes is 1.8m, and the chamber height for sewage pipes is 3.3m. It is difficult to meet the strength requirements of such a large inspection well with only plastic ribs. In particular, most of the municipal inspection wells are set under the roads, which are subject to vehicle loads and require higher strength for the inspection wells. This is also a difficult problem that restricts the application of plastic drainage inspection wells in municipal drainage pipelines.

The current standard drawing inspection well is divided into two structural forms: brickwork and concrete pouring. Most of the actual projects adopt brick structure, compared with concrete structure, brick has the advantages of simple construction and short construction period. However, the masonry requirements for brick drainage inspection wells are very high, the joint mortar should be full, and the waterproof mortar plastering surface in the well should be dense. Before the drainage pipeline is backfilled, a closed water test shall be carried out to test the sealing performance of the pipeline. The closed water test requires a well test, that is, the closed water test of the pipeline together with the inspection well. In actual construction, there are often quality hazards such as lax brick joints in the inspection well, especially the difficulty in masonry between the pipeline and the inspection well, and poor plastering in the well. In the standard diagram, the height of the plastering surface in the rainwater inspection well is 200mm above the top of the pipe, and the height of the plastering surface in the sewage inspection well is to the top of the well chamber. The water level of the closed water test is 2m above the inner top of the inspection well pipe in the most upstream of the test section, and the water level may be higher than the height of the plastering surface The phenomenon that the inspection well is easy to cause water leakage (especially the grout between the cover plate and the well body is the main part of the leakage), the closed water test caused by water leakage cannot meet the requirements, and it is necessary to re-plaster or even dismantle the inspection well and re-build. Water leakage will also occur if the inspection well of concrete poured on site is not compacted by vibration. Therefore, when applying standard drawings, designers generally require that the inside of the rainwater inspection well be wiped to the wellhead, and the inside and outside of the sewage inspection well to be wiped to the wellhead. Brick and concrete inspection wells require high technology and difficult construction. The on-site construction is greatly affected by the technical level of personnel, the construction quality is uneven, the construction period is long, and the airtight performance is not as good as that of plastic inspection wells.

Contents of the invention

The purpose of this utility model is to provide an assembled plastic municipal drainage inspection well, which is based on the structural size of the inspection well in the current standard drawing, and meets the maintenance requirements of the standardized launder, workbench and downhole. It is mainly composed of foundation, well bottom, well chamber, cover plate, well shaft, well head and well cover. The well bottom, well chamber, cover plate, well shaft and well head are made of plastic components and assembled on site. The reinforced concrete frame is used as the load-bearing structure, and the ground load and the earth pressure around the well are borne by the reinforced concrete, forming a mixed structure of plastic and reinforced concrete. This plastic-mixed structure has good airtightness of plastic and strong bearing capacity of reinforced concrete. Frame concrete pouring uses plastic wells as formwork, without the need for formwork support and formwork removal, saving materials and labor for formwork support and formwork removal. The beneficial effect is: it overcomes the defects that the existing plastic inspection wells are small, has no launder and well chamber, cannot be maintained in the well, and the plastic strength is low and is not suitable for making large-volume municipal inspection wells, making up for the prior art brick or concrete inspection Poor airtightness of the well, prone to water leakage, complicated construction procedures and long construction period.

The utility model is realized through the following technologies: an assembled plastic municipal drainage inspection well mainly consists of a foundation 1, a well bottom 2, a well chamber 3, a cover plate 4, a well shaft 5, a well head 6 and a well cover 7. The well bottom 2, the well chamber 3, the cover plate 4, the well shaft 5, and the wellhead 6 are components made of plastic, and the components are connected and assembled by sockets to form the well body of the inspection well. The inspection well is made of plastic components on site. Assembly combined with cast-in-place concrete construction, from bottom to top: foundation 1, well bottom 2, well chamber 3, cover plate 4, well shaft 5, well head 6, well cover 7. The well bottom 2 and the well chamber 3 together form a water passage section and a maintenance space. The well bottom 2 and the well chamber 3 are provided with a well chamber column 20 on the periphery, and the well chamber column steel bar 21 is arranged in the well chamber column. The well chamber column The lower end of the steel bar 21 is embedded in the foundation 1 . The bottom of the well 2 is composed of the outer frame 12 of the well and the inner wall of the well 13. The bottom of the inspection well is provided with an inlet pipe 8 and an outlet pipe 9. Between the inlet pipe 8 and the outlet pipe 9 is a launder 10. The two sides of the launder 10 The side is the workbench 11, and the space enclosed by the outer frame 12 of the well and the inner wall of the well 13 forms the well chamber column groove 14, which is used for setting the well chamber column 20, and the well chamber column 20 adopts concrete pouring. The lower part is filled with concrete and connected with the concrete of the well column 20 as a whole. The well chamber 3 is composed of the well outer frame 12 and the well inner wall 13 to form an operating space for inspection of well maintenance, and the space enclosed by the well outer frame 12 and the well inner wall 13 forms a well chamber column groove 14 for setting the well chamber The column 20 and the well column 20 are poured with concrete.

The cover plate 4 is installed on the upper part of the well chamber 3. The cover plate 4 is composed of the well cover outer frame 15 and the well cover inner wall 16. The steel bar 22 and the upper end of the well chamber column steel bar 21 extend into the cover plate 4 and connect with the cover plate steel bar 22; The wellbore 5 is arranged on the cover plate 4, the wellbore 5 is composed of the wellbore outer frame 17 and the wellbore inner wall 18, which is used for pipeline dredging and downhole maintenance. The enclosed space forms a shaft column groove 19 for setting the shaft column 23. The shaft column 23 adopts concrete pouring.

The wellhead 6 is a circular ring with the same diameter as the inner wall 18 of the wellbore, installed on the upper part of the wellbore 5, the wellhead 6 is surrounded by a well circle 25, the well circle steel bar 26 is arranged in the well circle 25, and the wellbore column steel bar 24 upper end extends into the well circle 25, It is connected with the steel bar 26 of the well circle; Well cover 7 is installed on the well circle 25,

The bottom of the well 2, the well chamber 3, the cover plate 4, the well shaft 5, and the wellhead 6 are provided with a ladder 27, and the ladder 27 is provided with steel bars covered with plastic, and the positions of each section are set up and down. Inside the concrete of the columns.

The above-mentioned structure constitutes a waterproof well body assembled by plastic components, and reinforced concrete is a plastic-concrete structure inspection well with a frame load-bearing structure.

The utility model is a factory-made plastic well body component, which is assembled and combined on site, and is a plastic-mixed inspection well formed by pouring a reinforced concrete frame. When pouring the frame concrete, the plastic well body is used as the formwork, and there is no need for formwork support and formwork removal, which saves materials and labor for formwork support and formwork removal. The cumbersome procedure of laying bricks or casting concrete in the municipal drainage inspection well in the prior art is omitted, and the construction speed and quality are easy to control.

Description of drawings

Fig. 1 is a plan view of the utility model;

Fig. 2 is this utility vertical sectional view;

Fig. 3 is a three-dimensional view of inspection well assembly;

Figure 4 is a three-dimensional view of the steel frame of the inspection well;

Fig. 5 is a three-dimensional view of the plastic components of the well chamber;

Fig. 6 is a three-dimensional view of the bottom plastic component;

Fig. 7 is a perspective view of the plastic component of the cover plate;

Fig. 8 is a three-dimensional view of the wellbore plastic component;

Fig. 9 is a perspective view of the wellhead plastic component.

In the figure: 1-foundation, 2-well bottom, 3-well chamber, 4-cover plate, 5-wellbore, 6-wellhead, 7-well cover, 8-water inlet pipe, 9-water outlet pipe, 10-launder, 11 -workbench, 12-well outer frame, 13-well inner wall, 14-well chamber column groove, 15-well cover outer frame, 16-well cover inner wall, 17-well shaft outer frame, 18-well shaft inner wall, 19-well shaft column groove , 20-well chamber column, 21-well chamber column steel bar, 22-cover plate steel bar, 23-well shaft column, 24-well shaft column steel bar, 25-well ring, 26-well ring steel bar, 27-ladder.

detailed description

The utility model is a well body composed of plastic components, which is assembled and assembled on site, and a reinforced concrete frame is arranged around the well body as a load-bearing plastic-mixed structure inspection well. The prefabricated plastic municipal drainage inspection well is mainly composed of a foundation 1, a well bottom 2, a well chamber 3, a cover plate 4, a well shaft 5, a well head 6 and a well cover 7. The plan view of the utility model is shown in Fig. 1, and the cutting position is horizontally cut along the center of the water inlet pipe 8 and the water outlet pipe 9; The well bottom 2, the well chamber 3, the cover plate 4, the well shaft 5 and the wellhead 6 are components made of plastic, and the components are connected and assembled by sockets to form the well body of the inspection well. Concreting construction, from bottom to top: foundation 1, well bottom 2, well chamber 3, cover plate 4, well shaft 5, well head 6, well cover 7. See Figure 3 for a perspective view of the assembly of the inspection well, in which the manhole cover 7 is not shown, and see Figure 4 for a perspective view of the steel frame of the inspection well.

Embodiment: Now take the circular drainage inspection well as an example to illustrate the structure and connection relationship of each part.

The well bottom 2 and the well chamber 3 together form the water passage section and the maintenance space. The well bottom 2 and the well chamber 3 are provided with a well chamber column 20 on the periphery. 21. The lower end of the steel bar 21 of the well chamber column is embedded in the foundation 1. See Figure 5 for the perspective view of the plastic components at the bottom of the well 2, and Figure 6 for the perspective view of the plastic components at the well chamber 3. The bottom of the well 2 is composed of the outer frame 12 of the well and the inner wall of the well 13. The bottom of the inspection well is provided with an inlet pipe 8 and an outlet pipe 9. Between the inlet pipe 8 and the outlet pipe 9 is a launder 10, and both sides of the launder 10 are working The space enclosed by the platform 11 , the well outer frame 12 and the well inner wall 13 forms a well column groove 14 for setting the well column 20 . The plane shape of the well outer frame 12 is a square, the plane shape of the well inner wall 13 is a circle, the square is circumscribed to a circle, the side length of the square is equal to the diameter of the circle, and a hypotenuse is formed between the four corners of the square and the circle. It is a triangle with an arc, which is the space enclosed by the outer frame 12 of the well and the inner wall of the well 13. The section of the well column 20 on the periphery of the well bottom 2 is a hypotenuse arc triangle, and the well column 20 adopts concrete pouring, and the launder 10 and The lower part of the workbench 11 is filled with concrete, which is integrated with the concrete of the well column 20 . The well chamber 3 is composed of the outer frame 12 of the well and the inner wall 13 of the well, which is used to check the operation space of the well maintenance. The enclosed space forms the well column groove 14 for setting the well column 20 . The bottom of the well 2 and the well chamber 3 form a circular waterproof well inner wall made of plastic, and the four corners are supported by reinforced concrete to support the water section and maintenance space. See Figure 2, Figure 3, and Figure 4.

The cover plate 4 is installed on the top of the well chamber 3, and the perspective view of the plastic components of the cover plate 4 is shown in FIG. 7 . The cover plate 4 is composed of the well cover outer frame 15 and the well cover inner wall 16 to form the formwork for pouring the cover plate 4 concrete, which is the transition section between the well chamber 3 and the well shaft 5. The cover plate 4 is provided with a cover plate steel bar 22, and the cover plate 4 adopts pouring concrete. The upper end of the well column steel bar 21 extends into the cover plate 4 and connects with the cover plate steel bar 22. The cover plate 4 is supported on the well room column 20 and is a load-bearing component of the inspection well, see Fig. 2, Fig. 3 and Fig. 4 .

The wellbore 5 is arranged on the cover plate 4. The perspective view of the plastic components of the wellbore 5 is shown in FIG. , the space enclosed by the wellbore frame 17 and the wellbore inner wall 18 forms a wellbore column groove 19 for setting the wellbore column 23, the planar shape of the wellbore outer frame 17 is a square, the planar shape of the wellbore inner wall 18 is a circle, and the square circumscribes a circle The side length of the square is equal to the diameter of the circle, and a triangle whose hypotenuse is an arc is formed between the four corners of the square and the circle, which is the space enclosed by the wellbore outer frame 17 and the wellbore inner wall 18, and the wellbore on the periphery of the wellbore 5 The section of the column 23 is a hypotenuse circular arc triangle. The shaft column 23 is poured with concrete. See Figure 2, Figure 3, and Figure 4.

The wellhead 6 is arranged on the top of the wellbore 5. The three-dimensional view of the plastic components of the wellhead 6 is shown in FIG. The upper end of the shaft column steel bar 24 extends into the well ring 25 and is connected with the steel bar 26 of the well ring; Well cover 7 is installed on the well circle 25, see Fig. 2, Fig. 3, Fig. 4.

For the sake of simplification of the drawing, in the perspective view of the above plastic component, the socket at the upper end of the component is not drawn.

Bottom 2, well chamber 3, cover plate 4, well shaft 5, and wellhead 6 are provided with a ladder 27, and steel bars are wrapped in plastic inside the ladder 27. The positions of each section are set up and down. The steel bars of the ladder 27 are anchored to the concrete of the corresponding section Inside. See Figure 1, Figure 2, Figure 3.

The above is the embodiment of the circular inspection well, the rectangular and fan-shaped inspection wells, the four corners of the well bottom 2 and the well chamber 3 are provided with tuck angles to form a triangular space for setting the well chamber column 20 . If the planar size of the inspection well is large, the four corner columns alone cannot meet the load-bearing requirements, and columns can be added in the middle through calculation.

The well bottom 2, the well chamber 3, the cover plate 4, the well shaft 5 and the well head 6 are components made of plastic, which are injection molded in the factory. The well bottom 2 is an independent component; the well chamber 3 is made into different heights and various specifications, and can be combined into well chambers of different heights; the height of the cover plate 4 is determined by calculation of the reinforced concrete structure. Bottom 2, well chamber 3, and cover plate 4 are determined by the size and shape of the inspection well according to the size of the pipe diameter. The shape is divided into circular, rectangular, and fan-shaped. Whether to turn and so on to determine. Shaft 5 is made into various specifications of different heights, to adapt to the combination of different height shafts, no matter what the inspection well is, the shaft 5 uniformly adopts a specification, preferably 700mm in diameter of the inner wall of the shaft. The wellhead 6 is an independent member with the same diameter as the wellbore inner wall 18. It is a long circular pipe, which can be intercepted according to the height. The height is determined according to the thickness of the well circle 25, generally about 200mm.

The construction of the prefabricated plastic municipal drainage inspection well adopts the method of on-site assembly of plastic components combined with cast-in-place concrete construction. From bottom to top: foundation 1, well bottom 2, well chamber 3, cover plate 4, well shaft 5, wellhead 6 , Manhole cover 7, assembled in sections from bottom to top combined with cast-in-place concrete construction, the construction method is as follows.

1) Make binding well chamber column steel bar 21, cover plate steel bar 22, shaft column steel bar 24, well ring steel bar 26.

2) The foundation 1 is poured on the excavated inspection well foundation, and the bundled well chamber column steel bars 21 are pre-embedded in the concrete of the foundation 1.

3) After the concrete of the foundation 1 is finally set, the well bottom 2 is installed on it, the space enclosed by the outer frame 12 of the well and the inner wall 13 of the well is covered with the steel bar 21 of the well column, and the position and elevation of the inlet pipe 8 and the outlet pipe 9 are adjusted , the well bottom 2 is fixed, the gap between the bottom and the foundation 1 is sealed with mortar, the well chamber column 20 concrete around the well bottom 2 is poured, vibrated with a vibrating rod, the concrete flows into the lower part of the launder 10 and the workbench 11, and the work The exhaust hole on the top surface of the platform 11 removes the air so that the concrete is filled compactly, and is connected with the concrete of the well column 20 as a whole.

4) After the concrete of the well chamber column 20 on the periphery of the well bottom 2 is finally set, the well chamber 3 is installed on the upper part of the well bottom 2, and the space enclosed by the outer frame 12 of the well and the inner wall of the well 13 covers the steel bar 21 of the well chamber column. Apply sealant to the socket at the joint between the well bottom 2 and the well chamber 3, insert the well chamber 3 into the socket of the well bottom 2, and pour the well chamber column 20 concrete on the periphery of the well chamber 3.

5) After the concrete of the well chamber column 20 around the well chamber 3 is finally set, install the cover plate 4 on the upper part of the well chamber 3, apply sealant on the socket at the joint between the well chamber 3 and the cover plate 4, and insert the cover plate 4 into the well In the socket of the chamber 3, place the cover plate steel bar 22, and bind firmly with the well chamber column steel bar 21 extending into the cover plate 4, install the shaft column steel bar 24 and pre-embed it in the cover plate 4, and pour the cover plate 4 concrete.

6) After the concrete of the cover plate 4 is finally set, the wellbore 5 is installed on the upper part of the cover plate 4, and the sealant is applied to the socket at the joint between the wellbore 5 and the cover plate 4, and the space enclosed by the wellbore outer frame 17 and the wellbore inner wall 18 is covered. Live the shaft column steel bar 24, pour the shaft column 23.

7) After the concrete of the wellbore column 23 reaches strength, backfill the earthwork around the inspection well and tamp it tightly. When filling to the top of the wellbore 5, install the wellhead 6 on the upper part of the wellbore 5. The bearing at the connection between the wellhead 6 and the wellbore 5 The socket is smeared with sealant, the wellhead 6 is inserted into the socket of the well shaft 5, the well ring steel bar 26 is placed, and is bound firmly with the well shaft column steel bar 24 extending into the well ring 25, and the concrete of the well ring 25 is poured.

Before the above-mentioned pouring of the well chamber column 20, the cover plate 4, and the shaft column 23 concrete, the ladder 27 should be inserted into the ladder installation hole of the corresponding component, and the ladder 27 should be fixed in the inspection well when pouring concrete.

8) After the concrete of the well circle 25 is finally set, fix the manhole cover 6 on it, and pave the road around the inspection well.

The structure described in the accompanying drawings of the utility model application document is only an embodiment of a circular inspection well, whether it is circular, rectangular, fan-shaped or other shapes, the well body is made of plastic components, and the drainage inspection of the load-bearing structure is made of reinforced concrete Wells are all within the protection scope of the present application.

Claims (7)

1. An assembled plastic municipal drainage inspection well, mainly composed of a foundation (1), a well bottom (2), a well chamber (3), a cover plate (4), a well shaft (5), a well head (6), and a well cover (7 ) composition, which is characterized in that: the well bottom (2), well chamber (3), cover plate (4), wellbore (5), and wellhead (6) are components made of plastic, and sockets are used between the components The well body of the inspection well is formed by means of connection and assembly. The inspection well adopts on-site assembly of plastic components combined with cast-in-place concrete construction. From bottom to top: foundation (1), well bottom (2), well chamber (3), cover plate (4), wellbore (5), wellhead (6), and well cover (7); the well bottom (2) and the well chamber (3) together form the water passage section and maintenance space, and the well bottom (2) and the well chamber The periphery of (3) is provided with a well chamber column (20), and the well chamber column reinforcement (21) is arranged inside the well chamber column (20), and the lower end of the well chamber column reinforcement (21) is embedded in the foundation (1); the cover plate ( 4) Installed on the upper part of the well chamber (3), the cover plate steel bar (22) is set inside the cover plate (4), the upper end of the well chamber column steel bar (21) extends into the cover plate (4), and the cover plate steel bar (22) ) connection; the wellbore (5) is arranged on the cover plate (4), and the wellbore column (23) is arranged on the periphery of the wellbore (5), and the wellbore column reinforcement (24) is arranged inside the wellbore column (23), and the wellbore column reinforcement (24 ) is buried in the cover plate (4); the wellhead (6) is set on the upper part of the wellbore (5), and the well circle (25) is arranged around the well circle (25), and the well circle steel bar (26) is set in the well circle (25), and the wellbore column steel bar (24) The upper end extends into the well circle (25) and connects with the well circle steel bar (26); the well cover (7) is installed on the well circle (25) to form a waterproof well body assembled from plastic components, reinforced concrete Inspection well for the plastic composite structure of the frame load-bearing structure. 2. The assembled plastic municipal drainage inspection well according to claim 1, characterized in that: the bottom of the well (2) is composed of the outer frame (12) of the well and the inner wall of the well (13). The inlet pipe (8) and the outlet pipe (9), between the inlet pipe (8) and the outlet pipe (9) is the launder (10), the two sides of the launder (10) are the workbench (11), the outer frame of the well (12) and the space enclosed by the inner wall of the well (13) form the well chamber column groove (14), which is used to set the well chamber column (20). The well chamber column (20) is poured with concrete, and the launder (10) and the working The bottom of the platform (11) is filled with concrete, which is connected as a whole with the concrete of the well column (20). 3. The prefabricated plastic municipal drainage inspection well according to claim 1, characterized in that: the well chamber (3) is composed of the outer frame (12) of the well and the inner wall (13) of the well for operation of maintenance of the inspection well Space, the space enclosed by the outer frame of the well (12) and the inner wall of the well (13) forms a well column groove (14), which is used for setting the well column (20), and the well column (20) is poured with concrete. 4. The prefabricated plastic municipal drainage inspection well according to claim 1, characterized in that: the cover plate (4) is composed of a well cover frame (15) and a well cover inner wall (16) to pour concrete for the cover plate (4) The formwork is the transition section between the well chamber (3) and the well shaft (5), the cover plate (4) is provided with a cover plate reinforcement (22), and the concrete is poured, and the upper end of the well chamber column reinforcement (21) extends into the cover plate (4 ), the cover plate (4) is supported on the well column (20), which is the load-bearing component of the inspection well. 5. The assembled plastic municipal drainage inspection well according to claim 1, characterized in that: the wellbore (5) is composed of a wellbore outer frame (17) and a wellbore inner wall (18) for pipe dredging and downhole maintenance The channel, the space enclosed by the shaft outer frame (17) and the shaft inner wall (18) forms a shaft column groove (19), which is used for setting the shaft column (23), and the shaft column (23) is poured with concrete. 6. The assembled plastic municipal drainage inspection well according to claim 1, characterized in that: the wellhead (6) is a ring with the same diameter as the inner wall (18) of the wellbore, installed on the upper part of the wellbore (5), A well ring (25) is arranged on the periphery of the wellhead (6), and a well ring steel bar (26) is arranged in the well ring (25), and the well ring (25) is poured with concrete, which is used as a support for the well cover (7). 7. The assembled plastic municipal drainage inspection well according to claim 1, characterized in that: the bottom of the well (2), the well chamber (3), the cover plate (4), the shaft (5), the wellhead (6 ) is provided with a ladder (27), and the ladder (27) is provided with reinforced outsourcing plastics, and the positions of each section are consistent up and down, and the steel bars of the ladder (27) are anchored in the concrete of the corresponding section column.