CN213508793U - A template system for construction of municipal concrete drainage pipe - Google Patents

Abstract

The utility model discloses a template system for municipal concrete drainage pipe construction. The template is an aluminum alloy rectangular template, and comprises a first template and an adjusting template, wherein positioning pin holes are formed in the four lateral sides and the back of the template; the steel structure back support comprises a steel skeleton, the steel skeleton comprises an outer vertical rod, an inner vertical rod, an upper cross rod, a lower cross rod and an inclined rod which are connected, the end part of the extending end of the upper cross rod is connected with a back support screw rod, the lower ends of the outer vertical rod and the inner vertical rod are respectively connected with an outer supporting leg and an inner supporting leg, the outer vertical rod is provided with two first positioning pins corresponding to positioning pin holes in the template, and the upper cross rod is provided with positioning pin holes corresponding to the outer supporting legs; the connecting flower stand is of a rectangular frame structure, and two short sides of the connecting flower stand are respectively connected with second positioning pins corresponding to positioning pin holes arranged on the inner vertical rods; the four corners of the pedal are provided with connecting holes corresponding to the connecting holes arranged on the upper cross rod.

Description

A template system for construction of municipal concrete drainage pipe

Technical Field

The utility model relates to a template system for municipal concrete drainage pipe construction belongs to building construction technical field.

Background

The municipal drainage pipeline adopts a non-pressure drainage design, so that rain sewage in the pipeline flows according to a pipeline ramp. As urban underground pipelines are various in variety, in order to prevent the urban underground pipelines from colliding with pipelines such as tap water, reclaimed water, electric power, fuel gas and heat power in elevation, the buried depth of the drainage pipeline is 3-7 m in common. Drainage pipelines are usually laid by a grooving method, and the excavation of a groove is supported by the Larsen steel sheet pile matched with the inner support system of the enclosing purlin.

According to the related spirit of the national implementation of building standardization, municipal drainage pipelines are constructed according to the standard atlas of municipal drainage pipeline engineering and accessory facilities 06MS 201. According to the requirements of a drawing set and a design drawing, after a pipe laying process, in order to prevent a socket joint from falling off, a pipeline foundation needs to be encapsulated, a foundation encapsulation supporting angle is generally 180 degrees or 120 degrees, and the encapsulated concrete continuously extends along the longitudinal direction of a pipe ditch from a pipeline base to two sides. The traditional foundation concrete construction method at present is a glued wood formwork and square timber support system, and the formwork system has the following outstanding defects: firstly because pipeline construction is located moist wet water environment more, the plywood deformation damage is fast, and the turnover number of times is few, is generally 3 ~ 4 times, and extravagant very serious. Secondly, the plywood has large deformation when being reused, particularly has serious corner damage, poor sealing performance and installation precision of the template and poor engineering quality. Thirdly, the template and the square timber need to be cut according to the size of the foundation concrete, the material waste is serious, the field is messy, and the civilized construction is poor. Fourthly, construction operation is carried out in the deep groove, the operation space on two sides of the pipeline is narrow, the sizes of components such as a template back support and the like are irregular, the weight is large, the speed of installing and dismantling the template is very slow, and the labor intensity of workers is very high. Fifthly, a construction operation platform and a walking channel along the longitudinal direction of the groove are not provided, the concrete pouring operation is very inconvenient, and great potential safety hazards exist.

Disclosure of Invention

To the above-mentioned defect that exists among the prior art, the utility model provides a template system of standardization, modular design, it has high strength rigidity, installs and demolishs convenient, construction convenient operation's characteristics.

The utility model discloses a realize through following technical scheme: the utility model provides a template system for municipal concrete drainage pipe construction, characterized by: the device comprises a template, a steel structure back support, a connecting flower stand, an inclined support rod and a pedal, wherein the template is a rectangular template, the template is an aluminum alloy template, the template comprises a first template and an adjusting template, and positioning pin holes are formed in the four lateral sides and the back of the template; the steel structure back support comprises a section steel framework, the section steel framework comprises an outer vertical rod and an inner vertical rod which are vertically arranged, the upper ends of the outer vertical rod and the inner vertical rod are connected with a horizontal upper transverse rod, one end of the upper transverse rod close to the inner vertical rod extends outwards, the lower ends of the outer vertical rod and the inner vertical rod are connected with a horizontal lower cross rod, an inclined rod is fixedly connected between the extending end of the upper cross rod and the lower end of the inner vertical rod, the end part of the extending end of the upper cross rod is connected with an adjustable back-supporting screw rod, the lower end of the outer vertical rod is connected with an adjustable outer supporting leg, the lower end of the inner vertical rod is connected with an adjustable inner supporting leg, two first positioning pins are arranged on the outer side of the outer vertical rod at intervals along the height direction, the first positioning pin corresponds to a positioning pin hole on the template, and a positioning pin hole corresponding to the outer support leg is arranged on the upper cross rod; the connecting flower stand is of a rectangular frame structure, two second positioning pins are fixedly connected to two short sides of the connecting flower stand respectively, and the second positioning pins correspond to positioning pin holes formed in the inner vertical rods; two ends of the diagonal brace are respectively provided with a connecting pin hole; the pedal is of a rectangular structure, and connecting holes corresponding to the connecting holes formed in the upper cross rod are formed in the four corners of the pedal.

The utility model discloses in, the template adopts first template and adjusts the template, and first template is standard template, can choose different standard module and adjust the template for use to make up according to the difference of basic encapsulation concrete size during the construction. The utility model provides a steel construction back of body props and connects at the template dorsal part when being used for the construction, and steel construction back of body props perpendicular to template face-mounting, arranges with having the interval, and steel construction back of body props its locating pin of accessible and is connected with the locating pin hole in the template, and steel construction back of body props the other end and can push up tightly through the back of body props the screw rod and maintain the steel sheet pile, plays the supporting role to the template. The connecting flower shelf is used for connecting two adjacent steel structure back supports during construction, and the template, the steel structure back supports and the connecting flower shelf form a stable space integral structure. The steel framework of the steel structure back support is arranged in a vertical plane in a vertical direction when the flower stand is connected, and the positioning pins penetrate through the corresponding positioning pin holes in the inner vertical rods of the steel framework to realize connection. The footboard is used for as the operation platform during construction, directly sets up on shaped steel skeleton's last horizontal pole during the installation, and the connecting hole of footboard four corners is counterpointed with the connecting hole on shaped steel skeleton's the last horizontal pole, and accessible bolted connection is fixed. The utility model provides a steel construction back-support can set up one deck or multilayer according to the difference of encapsulation concrete size when the construction, and when setting up multilayer steel construction back-support, the connection between the upper and lower steel construction back-support inserts the downthehole realization connection location of locating pin that corresponds on the last horizontal pole of lower floor's steel construction back-support through the outer leg of upper steel construction back-support. The back support screw rod, the outer support leg and the inner support leg can be adjusted in length. The utility model provides a diagonal brace is used for when basic encapsulation concrete size is less than using the steel construction back-up support or basic encapsulation concrete size is great, and when the size of template size and steel construction back-up support can't match, uses the diagonal brace to link together template and the ground anchor bar of lower part or the steel construction back-up support of lower part, supports the template.

Further, in order to keep the back-supporting system perpendicular to the formwork surface and prevent torsion, the cross section of the first positioning pin is square.

Further, in order to ensure light weight, the outer vertical rod, the inner vertical rod, the upper cross rod, the lower cross rod and the inclined rod of the steel skeleton are all channel steel.

Further, in order to ensure light weight, the pedal is made of aluminum alloy or galvanized steel sheets.

Further, for the convenience of supporting, backing plates are arranged at the outer side end of the back support screw rod, the lower end of the screw rod of the inner supporting leg and the screw rod of the outer supporting leg.

Furthermore, the corner connecting piece comprises a connecting piece body processed by equilateral angle steel, and positioning pin holes corresponding to the positioning pin holes in the template are formed in two limb edges of the connecting piece body.

The utility model has the advantages that:

1. the design of the shaped metal template is adopted, the processing and mounting precision of the template is high, and the concrete construction quality is easy to control.

2. By adopting the light weight design, the weight of various components such as the aluminum alloy template, the steel structure back support, the pedal and the like is light, the weight of the maximum single piece is not more than 18kg, the weight is only one third of that of the same type of steel template, mechanical equipment is not needed, and the labor intensity of workers is greatly reduced.

3. The standardized and modularized sizing design is adopted, the mounting and dismounting speed of the template is high, and the dismounting can be quickly completed by only two persons matching and using portable tools such as a spanner.

4. The aluminum alloy template has the advantages of light weight, high strength, corrosion resistance, excellent corrosion resistance, suitability for damp and wet underground engineering construction operation environment, turnover use for more than 200 times which is far higher than that of plywood for 3-4 times, high recycling value, resource saving and environment protection.

5. The pipeline laying construction environment is severe, the space is narrow, and by laying the pedal, a safe, stable and smooth operating platform and a walking channel are provided for workers, so that the potential safety hazard is reduced, and the construction efficiency is improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a die plate system in the case of a 400mm pipe diameter in an embodiment;

FIG. 2 is a schematic cross-sectional view of a template system in the case of a 600mm tube diameter in an embodiment;

FIG. 3 is a schematic cross-sectional view of a template system in the case of a 1000mm pipe diameter in an embodiment;

FIG. 4 is a schematic cross-sectional view of a die plate system in the case of a 1200mm tube diameter in an embodiment;

FIG. 5 is a schematic plan view of the present invention in an embodiment (one side of which does not show the pedal);

FIG. 6 is a schematic front view of a template in the present invention in accordance with an embodiment;

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a rear view of FIG. 6;

fig. 9 is a schematic structural view of a steel structure back support in the present invention according to the specific embodiment;

fig. 10 is a schematic view of a connection structure between a screw and a channel steel in the steel structure back support according to the embodiment of the present invention;

FIG. 11 is a schematic view of the connecting flower shelf according to the present invention;

FIG. 12 is a schematic view of a corner connector according to the present invention;

in the figure, 1, a template, 1-1, a panel, 1-2, a stiffening rib, 1-3, a positioning pin hole on the template, 2, a steel structure back support, 2-1, a profile steel framework, 2-1-1, an upper cross rod, 2-1-2, a lower cross rod, 2-1-3, an outer vertical rod, 2-1-4, an inner vertical rod, 2-1-5, an inclined rod, 2-2, a back support screw rod, 2-3, an outer support leg, 2-4, an inner support leg, 2-5, a first positioning pin, 2-6, a backing plate, 2-7, a positioning pin hole, 2-8, a connecting hole, 2-9, a positioning pin hole, 3, a connecting flower stand, 3-1, a second positioning pin, 4, an inclined support rod, 5, a pedal, 6, a concrete cushion layer, 7 and a concrete foundation, 8. the steel sheet pile comprises a steel sheet pile body 9, a pipeline 10, a screw rod 11, a positioning steel sheet 12, a positioning steel sheet 13, channel steel 14, a connecting piece body 15, a positioning pin hole 16 and a rib plate.

Detailed Description

The invention will now be further described by way of non-limiting examples with reference to the accompanying drawings, without limiting the invention thereto. The utility model discloses only concentrate the socket joint type concrete pipe foundation type of common use to standard drawing, other types are not the utility model discloses an in the research range.

As shown in the attached drawings, the template system for municipal concrete drainage pipeline construction comprises a template 1, a steel structure back support 2, a connecting flower stand 3, inclined support rods 4 and pedals 5.

The template 1 is a rectangular template, and the template 1 is an aluminum alloy template. The aluminum alloy formwork 1 consists of a panel 1-1 and grid type stiffening ribs 1-2 arranged on the back side of the panel, the thickness of the panel 1-1 is 5-6 mm according to construction load and precision requirements of foundation encapsulation concrete, the stiffening ribs 1-2 are combined by rib plates and angle iron, the height of the ribs is about 8cm usually, and the specific size is determined according to load calculation, so that the aluminum alloy formwork can meet the requirements of torsion resistance and deformation. According to the standard atlas, the sizes of the foundation encapsulation concrete required by pipelines with different pipe diameters are different. According to the requirements of standardization and universality, the template 1 is divided into a first template and an adjusting template, the first template is a standard template, and the following table shows that:

template numbering

Standard board

Template numbering

Adjusting plate 1

Template numbering

Adjusting plate

2

A1

1.2*0.64m

B1

0.6*0.64m

C1

0.2*0.64m

A2

1.2*0.32m

B2

0.6*0.32m

C2

0.2*0.32m

A3

1.2*0.16m

B3

0.6*0.16m

C3

0.2*0.16m

The concrete thickness is encapsulated by the foundation of different pipe diameters in common use at all, and the use combination mode of the template is shown in the following table:

serial number	Inner diameter of pipeline	Thickness of foundation	Template number combination
				1	400mm	0.32m	2
2	600mm	0.48m	2+3
				3	800mm	0.64m	1
4	1000mm	0.8m	1+3
				5	1200mm	0.96m	1+2
6	1500mm	1.2m	1+1
				7	1800mm	1.44m	1+1+3

The four sides and the back of the side direction of the template are provided with a plurality of positioning pin holes 1-3. When the adjusting template is mainly used for construction and is installed to the last template, the proper B-type or C-type adjusting template can be selected for extension adjustment according to the actual measured length.

The steel structure back support 2 comprises a steel section frame 2-1, the steel section frame 2-1 is of an in-plane structure, the section steel framework 2-1 comprises an outer vertical rod 2-1-3 and an inner vertical rod 2-1-4 which are vertically arranged, the upper ends of the outer upright stanchion 2-1-3 and the inner upright stanchion 2-1-4 are connected with a horizontal upper cross bar 2-1-1, one end of the upper cross bar 2-1-1 close to the inner upright stanchion 2-1-4 extends outwards, the lower ends of the outer vertical rods 2-1-3 and the inner vertical rods 2-1-4 are connected with a horizontal lower cross bar 2-1-2, an inclined rod 2-1-5 is fixedly connected between the extending end of the upper cross rod 2-1-1 and the lower end of the inner vertical rod 2-1-4. The outer vertical rod 2-1-3, the inner vertical rod 2-1-4, the upper cross rod 2-1-1, the lower cross rod 2-1-2 and the diagonal rods 2-1-5 are all made of channel steel, all the rod pieces are connected by welding, the openings of the channel steel are inward during welding, specifically, the openings of the channel steel of the upper cross rod are downward, the openings of the lower cross rod are upward, the openings of the outer vertical rod and the inner vertical rod are opposite, and the openings of the diagonal rods are upward. In order to ensure the strength of the profile steel framework, inclined rods can be arranged between the rod pieces as required, and the inclined rods can be made of angle steel. The end part of the extending end of the upper cross rod 2-1-1 is connected with an adjustable back-supporting screw rod 2-2, the lower end of the outer upright rod 2-1-3 is connected with an adjustable outer supporting leg 2-3, and the lower end of the inner upright rod 2-1-4 is connected with an adjustable inner supporting leg 2-4. The back-supporting screw rods 2-2, the outer supporting legs 2-3 and the inner supporting legs 2-4 are all of screw rod structures, the connection between each screw rod and the corresponding channel steel adopts a structure as shown in the attached drawing 10, and two steel plates are welded at intervals at the connecting ends of the corresponding channel steel respectively: the positioning steel plate 11 and the positioning steel plate 12 are respectively provided with a positioning hole, the screw rod is inserted into the positioning hole, and the length of the screw rod is adjusted through a matched nut. In the embodiment, backing plates 2-6 are arranged at the outer side end of the back support screw rod 2-2, the lower end of the screw rod of the inner support leg 2-4 and the screw rod of the outer support leg 2-3, wherein the backing plates 2-6 of the back support screw rod 2-2 are connected in a welding mode, an internal thread is arranged at the center of the backing plate on the screw rod of the outer support leg 2-3 and is in threaded connection with the screw rod of the outer support leg 2-3, and the position of the backing plate can be adjusted on the screw rod of the outer support leg 2-3. The supporting legs can play a role in supporting and can also play a role in positioning and anchoring.

Two first positioning pins 2-5 are arranged on the outer side of the outer vertical rod 2-1-3 at intervals along the height direction, and the first positioning pins 2-5 correspond to the positioning pin holes 1-3 on the template. The steel structure back support 2 is perpendicular to the surface of the template when being installed, the arrangement distance is 60cm, and the steel structure back support 2 is connected with the positioning pin holes 1-3 on the template through the first positioning pins 2-5 on the outer vertical rods 2-1-3. In order to keep the back-up system perpendicular to the face of the formwork and prevent twisting, the first positioning pins 2-5 are preferably square in cross-section.

And the upper cross rod 2-1-1 is provided with a positioning pin hole 2-8 corresponding to the outer support leg 2-3. According to the concrete pipe diameter size of laying, when adopting individual layer steel construction back shore 2 to support, the screw rod of outer landing leg can stretch into in the bed course and regard as the anchor location muscle of template. When the double-layer steel structure back support 2 is adopted for supporting, the outer leg screw of the upper layer back support 2 can extend into the positioning pin hole on the upper cross bar of the lower layer steel structure back support 2 to connect and fix the upper and lower layers of steel structure back supports 2.

The standard design working height of the steel skeleton 2-1 is 48cm, wherein the height of the upright is 42cm, and the height of the support legs is 6 cm. The length of the lower cross rod in the width direction is 20cm, the length of the upper cross rod is 40cm, the adjusting length of the back-up screw rod is 0-30 cm, and the designed working width is 40-70 cm. The operation width of concrete pipeline laying construction both sides is 50 ~ 90cm generally, considers template and stiffening rib thickness, can satisfy the operation requirement basically. For the case that the width of each groove exceeds the stroke of the screw, a square wood block with 10cm or 15cm between the backing plate and the steel sheet pile enclosure can be supported.

The connecting flower shelf 3 is of a rectangular frame structure, the connecting flower shelf 3 is welded into a rectangular frame by adopting L40 x 40 x 3mm equilateral angle steel, and two crossed oblique rods are arranged in the rectangular frame. The connecting pergola 3 is about 52cm in length and 30cm in width. Two second positioning pins 3-1 are fixedly connected to two short edges of the connecting flower shelf 3 respectively, and the two second positioning pins 3-1 correspond to two positioning pin holes 2-9 arranged on the inner vertical rods 2-1-4. The connecting flower shelf 3 is used for connecting two adjacent steel frameworks 2-1, so that the template 1, the steel frameworks 2-1, the connecting flower shelf 3 and the anchoring ribs form a stable spatial integral structure. When the connecting flower shelf 3 is installed, the connecting flower shelf is arranged in a vertical plane perpendicular to the steel skeleton 2-1, and the second positioning pin 3-1 is directly penetrated into the corresponding positioning pin hole 2-9 on the steel skeleton to realize connection. The connecting flower shelf 3 is equal to the top surface of the steel framework after being installed, and the pedal 5 erected on the upper part is kept stable.

The diagonal rod 4 is formed by processing round steel with the diameter of 25mm, and connecting pin holes are formed in two ends of the diagonal rod 4 and can be quickly connected and installed. When in use, one end of the steel structure props against the template, and the other end of the steel structure props against the ground anchoring rib or the steel structure back support at the lower part. The diagonal stay 4 is used in the following cases: firstly, when the pipe diameter is 400mm, a 2-type template is directly adopted, namely the vertical mold height of the template is 0.32m, the template is supported by inclined support rods 4 matched with ground anchor bars, and a steel structure back support 2 is not needed. Secondly, when the pipe diameter is 1000mm, the thickness of the corresponding basic encapsulation concrete is 0.8m, a 1-type template and a 3-type template are combined, the height of the template is 0.8m, a single-layer steel structure back support 2 is adopted at the back, and a part of the template with the upper height of 0.32m needs to be supported by an inclined support rod 4. Thirdly, when the pipe diameter is 1500mm, the thickness of the corresponding basic encapsulation concrete is 1.2m, two 1-type templates are combined, the height of each template is 1.28m, a double-layer steel structure back support 2 is adopted behind the template, and a part with the upper part height of 0.32m of the template needs to be supported by an inclined support rod 4.

The pedal 5 is of a rectangular structure, is designed to be light, and is made of aluminum alloy or galvanized steel sheets. The four corners of the pedal 5 are provided with connecting holes which correspond to the connecting holes 2-8 reserved on the upper cross rod 2-1-1. During installation, the pedal 5 is directly erected on the upper cross rod of the steel structure back support 2, and is fixed with the steel structure back support through the reserved connecting holes of the pedal and the steel structure back support. The span of the footplate is not more than 60cm, and the connecting flower stand 3 can support the long edge of the footplate 5, so the steadiness of the footplate is good.

Be connected for end cap template and longitudinal formwork for being convenient for, the utility model discloses still include the corner connecting piece, the corner connecting piece is including the connecting piece body 14 that adopts equilateral angle steel processing, two limb edges of connecting piece body 14 be provided with the corresponding location pinhole 15 of location pinhole in the template. The corner connecting piece is processed by adopting 63-6 mm equal-edge angle steel, and a plurality of stiffening rib plates 16 are welded in a direction perpendicular to the axial direction of the angle steel, so that the rigidity of the connecting piece is enhanced.

The utility model provides an outer landing leg, inner leg, back of the body prop the screw rod and can penetrate in the corresponding locating hole of shaped steel skeleton in advance, use with shaped steel skeleton is whole, transport, the installation is dismantled more conveniently, saves the cost of labor. If the damage and the deformation exist, the disassembly and the replacement can be conveniently carried out.

The utility model provides a locating pin is as the auxiliary component of template system, and the effect is connected and fixes a position each component, can adopt different cross sectional shape and size according to position and operation requirement.

The utility model discloses a standardized, modular design scale design can carry out the outfit and the combination of template to the situation of different pipe diameters, need not to reform transform the template at the job site, and the installation and dismantle fastly, only need two people's cooperations to utilize simple tools such as spanners can accomplish the dismouting fast.

Other parts in this embodiment are the prior art, and are not described herein again.

Claims (6)

1. The utility model provides a template system for municipal concrete drainage pipe construction, characterized by: the flower shelf comprises a template (1), a steel structure back support (2), a connecting flower shelf (3), an inclined support rod (4) and a pedal (5), wherein the template (1) is a rectangular template, the template (1) is an aluminum alloy template, the template (1) comprises a first template and an adjusting template, and positioning pin holes are formed in the four lateral sides and the back of the template; the steel structure back support (2) comprises a steel skeleton (2-1), the steel skeleton (2-1) comprises an outer vertical rod (2-1-3) and an inner vertical rod (2-1-4) which are vertically arranged, the upper ends of the outer vertical rod (2-1-3) and the inner vertical rod (2-1-4) are connected with a horizontal upper cross rod (2-1-1), one end of the upper cross rod (2-1-1) close to the inner vertical rod (2-1-4) extends outwards, the lower ends of the outer vertical rod (2-1-3) and the inner vertical rod (2-1-4) are connected with a horizontal lower cross rod (2-1-2), an inclined rod (2-1-5) is fixedly connected between the extending end of the upper cross rod (2-1-1) and the lower end of the inner vertical rod (2-1-4), the end part of the extending end of the upper cross rod (2-1-1) is connected with an adjustable back-support screw rod (2-2), the lower end of the outer vertical rod (2-1-3) is connected with an adjustable outer supporting leg (2-3), the lower end of the inner vertical rod (2-1-4) is connected with an adjustable inner supporting leg (2-4), two first positioning pins (2-5) are arranged on the outer side of the outer vertical rod (2-1-3) at intervals along the height direction, the first positioning pins (2-5) correspond to positioning pin holes in the template, and the upper cross rod (2-1-1) is provided with positioning pin holes corresponding to the outer supporting legs (2-3); the connecting flower stand (3) is of a rectangular frame structure, two second positioning pins (3-1) are fixedly connected to two short sides of the connecting flower stand (3) respectively, and the second positioning pins (3-1) correspond to positioning pin holes formed in the inner vertical rods (2-1-4); two ends of the diagonal brace (4) are respectively provided with a connecting pin hole; the pedal (5) is of a rectangular structure, and connecting holes corresponding to the connecting holes formed in the upper cross rod (2-1-1) are formed in the four corners of the pedal (5).

2. The formwork system for municipal concrete drainage pipeline construction according to claim 1, wherein: the cross section of the first positioning pin (2-5) is square.

3. The formwork system for municipal concrete drainage pipeline construction according to claim 1, wherein: the outer vertical rod (2-1-3), the inner vertical rod (2-1-4), the upper cross rod (2-1-1), the lower cross rod (2-1-2) and the diagonal rod (2-1-5) of the steel skeleton (2-1) are all channel steel.

4. The formwork system for municipal concrete drainage pipeline construction according to claim 1, wherein: the pedal (5) is made of aluminum alloy or galvanized steel sheet.

5. The formwork system for municipal concrete drainage pipeline construction according to claim 1, wherein: backing plates are arranged at the outer side end of the back support screw rod (2-2), the lower end of the screw rod of the inner supporting leg (2-4) and the screw rod of the outer supporting leg (2-3).

6. The formwork system for municipal concrete drainage pipeline construction according to claim 1, 2, 3, 4 or 5, wherein: the corner connecting piece comprises a connecting piece body (14) machined by adopting equal-edge angle steel, and positioning pin holes corresponding to the positioning pin holes in the template are formed in two limb edges of the connecting piece body (14).

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