CN210621475U - Cast-in-situ bent cap assembled steel pipe support - Google Patents

Abstract

The utility model relates to a cast-in-place bent cap assembled steel pipe support to current medium flask of the same kind and connecting elements structural design not good enough, the support is whole to be under construction and demolish comparatively inconvenient technical problem and design. The steel pipe support is characterized in that a sand box is arranged at the joint of a main beam and a steel pipe buttress of the steel pipe support, C40 concrete is arranged on the upper layer of the sand box, medium-coarse sand is arranged on the lower layer of the sand box, an inner steel pipe of a sand box top flange plate is arranged in an outer steel pipe of a sand box bottom flange plate, the sand box bottom flange plate is arranged on the steel pipe buttress top flange plate at the top of the steel pipe buttress, double-spliced steel is arranged at the top of the sand box top flange plate, a U-shaped clamp penetrates through bolt holes of the sand box top flange plate and bolt holes of the sand box bottom flange plate downwards in sequence after sleeving the steel section of the main beam from two sides of the upper part of the main beam, the double-spliced steel, the sand box and the steel pipe buttress top flange plate are fixed into a whole through double nuts.

Description

Cast-in-situ bent cap assembled steel pipe support

Technical Field

The utility model relates to a cast-in-place bent cap support of concrete and construction are cast-in-place bent cap assembled steel pipe support.

Background

The capping beam is an upper load for supporting, distributing and transmitting a cross beam on a building, and mainly has the functions of supporting an upper structure of a bridge and transmitting all loads to the lower part, the cross beam is arranged at the top of a framed bent pier, some conventional bridge piles are directly connected with the capping beam, and other bridge piles are connected with the capping beam after being connected with the upright post. Some existing bent caps adopt simply-supported bridges, such as application number 200910048036.6 disclosed in Chinese patent literature, application publication date 2009.09.23, and the invention name of 'construction method for converting simply-supported beams into post-cast hidden bent caps of continuous beams'; other bent caps adopt bent cap piers of single-column piers, such as application number 201710855483.7 disclosed in Chinese patent literature, application publication No. 2018.02.02, the invention name of 'large steel pipe truss for bent cap cast-in-situ construction and construction method'; some cover beams are cast in situ by using templates, such as application number 201310290955.0 disclosed in Chinese patent documents, application publication number 2013.11.06, the invention name 'a support for cast in situ box beams and a building method thereof'; and the invention discloses a construction method of a wide concrete PK box girder support system, such as application number 201811436101.8 disclosed in Chinese patent literature, application publication date 2019.02.15. But the sand box structures of the products and the like need to be further improved, and connecting members for welding the steel pipe bracket and the standard knot need to be further improved in the installation construction of the lower cross beam with the built-together track; meanwhile, the steel pipe support is inconvenient to transport and assemble on site, the mode of engineering manufacturing production and splicing on site is less adopted, the construction time is influenced, and the requirements on construction and transportation environments are high.

Disclosure of Invention

In order to overcome the defects, the utility model aims to provide a cast-in-place bent cap assembled steel pipe support to this field, make it solve present flask of the same kind and connecting element structural design not good enough, the support is whole to be under construction and to demolish comparatively inconveniently to and the support mounting is comparatively complicated, the more technical problem of the manpower time that consumes. The purpose is realized by the following technical scheme.

A cast-in-place bent cap assembled steel pipe support comprises a main body of the steel pipe support, a steel pipe buttress and a profile steel support, wherein a bent cap is formed by casting a pier column in place through a profile steel support upper template at the top of the steel pipe buttress, and the bent cap and the pier column are connected into a whole through reinforced concrete; the bottom of the steel pipe buttress is respectively provided with a support foundation, the top of the steel pipe buttress is provided with a main beam, the top of the main beam is sequentially provided with a secondary beam, a main ridge, a secondary ridge and a template, and two sides of the main beam are provided with guardrails; the structural design key points are that a sand box is arranged at the joint of a girder and a steel pipe buttress, the upper layer of the sand box is C40 concrete, the lower layer of the sand box is medium coarse sand, the upper layer of the sand box is arranged in an inner steel pipe at the bottom of a sand box top flange, the top surface of C40 concrete is flush with the top surface of the inner steel pipe, the medium coarse sand is arranged in an outer steel pipe of a sand box bottom flange, the inner steel pipe of the sand box top flange is inversely arranged in the outer steel pipe of the sand box bottom flange, the sand box bottom flange is arranged in the steel pipe buttress top flange at the top of the steel pipe buttress, double-spliced steel sections are arranged at the top of the sand box top flange, a U-shaped clamp sequentially penetrates through bolt holes of the sand box top flange, bolt holes of the sand box bottom flange and bolt holes of the steel pipe buttress top flange from the two sides of the girder and then fixes the girder, the double-spliced steel pipe, the U-shaped clamp is a U-shaped screw rod. Thereby pass through the fixed as an organic whole of U shaped card between the steel pipe buttress of sand box department and the girder to further strengthen the bearing capacity of girder through double pin shaped steel, above-mentioned sand box department structure is demolishd comparatively conveniently simultaneously.

And a bolt seal is arranged at the bottom of one side of the outer steel pipe of the sand box bottom flange plate, and a bolt is arranged in a bolt hole at the bolt seal. The bolt seal is convenient for removing coarse sand in the outer steel pipe, so that the sand box structure is more convenient to disassemble.

The bottom section of the steel pipe buttress is lengthened through the standard section, the bottom section is arranged on the support foundation, the bottom section embedded steel plate of the bottom section is arranged on the support foundation, the bottom section embedded steel plate is provided with a steel pipe buttress bottom flange plate, the steel pipe buttress bottom flange plate is welded and fixed with the bottom section embedded steel plate through a clamping plate, and the clamping plate is L-shaped. The steel pipe buttress of being convenient for of above-mentioned structure passes through the end festival and installs on the support basis to and make things convenient for dismantling of end festival, according to the concrete construction condition, partial steel pipe buttress passes through standard festival extension installation.

Standard joint flange plates are respectively arranged at the tail ends of four steel pipes on a standard joint of the steel pipe buttress, the standard joint and the standard joint are connected through the standard joint flange plates and high-cavity bolts, a triangular steel plate stiffening plate is arranged at the joint of the standard joint flange plates and the steel pipe buttress, and a horizontal support and an inclined support are arranged between the top and the bottom in the standard joint; the steel pipe buttress at the top of the stair is provided with a construction operation platform, and the stair are arranged in the standard knot. Thereby the steel pipe buttress passes through the standardized production preparation of mill and accomplishes the back, transports to the construction site through haulage vehicle, and the installation of steel pipe buttress can be realized in the hoist and mount of construction site, has improved the progress of construction, has reduced the restriction of construction condition.

The support foundation of the steel pipe buttress is provided with a cast-in-place bar foundation, a foundation embedded steel plate is arranged in the bar foundation, the bottom of the foundation embedded steel plate is provided with C12 anchoring steel bars, and the arrangement distance is 20 cm; the top of the bearing platform of the strip foundation is provided with a steel pipe, the bottom elevation of the steel pipe is-26 m, the top of the steel pipe is fixedly connected by adopting a horizontal brace and an inclined brace, the top of the steel pipe is provided with an H-shaped steel carrying pole beam along the bridge direction, the two rows of steel pipes in the middle are provided with double-spliced H-shaped steel carrying pole beams, the rest are provided with single carrying pole beams, and the top of the carrying pole beam is provided with a triple-spliced H-shaped steel bearing beam along the bridge direction. The concrete support foundation structure has the advantages of simple construction and firm structure.

A lower cross beam with a track built together is arranged below the cover beam, a steel pipe buttress below the beam top of the lower cross beam is a welded steel pipe buttress, and the welded steel pipe buttress is connected with a standard joint of the steel pipe buttress through a steel pipe buttress top flange plate; the joint is provided with three-spliced section steel, the three-spliced section steel is a three-spliced 32a I-shaped steel tie beam, and steel pipe buttress top flange plates on two sides of the three-spliced section steel pass through the U-shaped clamp and the double nuts are fixed into a whole. The construction embodiment of the double-layer viaduct built together on the rails is described above.

The utility model has reasonable structural design, convenient construction, installation and removal, especially reasonable structural design at the sand box, convenient construction, installation and removal; the cast-in-place bent cap steel pipe support is suitable for being used and constructed as a cast-in-place bent cap steel pipe support of a viaduct bridge and a common rail dual-purpose bridge, and the structural improvement and the construction improvement of similar products.

Drawings

Fig. 1 is a schematic structural view of a construction state according to an embodiment of the present invention, in which a frame portion is enlarged.

FIG. 2 is a schematic view of the structure of the flask of FIG. 1, with the main beam omitted.

Fig. 3 is a schematic top view of the structure of fig. 2.

Fig. 4 is a schematic top view of the bottom section of fig. 1.

Fig. 5 is a side view schematic diagram of the bottom section of fig. 4.

Fig. 6 is a schematic view of the formwork of fig. 1 in a pre-installation configuration.

Fig. 7 is a schematic view of the construction rear cap beam of fig. 1.

Fig. 8 is a schematic structural view of a second construction state according to an embodiment of the present invention.

Fig. 9 is a schematic structural view of the third construction state according to the embodiment of the present invention.

Fig. 10 is a schematic structural diagram of four construction states according to an embodiment of the present invention.

Fig. 11 is a schematic structural diagram of a fifth construction state according to an embodiment of the present invention.

Fig. 12 is a first schematic view of the construction structure of the lower beam of the present invention.

Fig. 13 is a left side view of the structure of fig. 12.

FIG. 14 is a schematic structural view of the joint between the standard knot of FIG. 13 and the welded steel pipe buttress.

Fig. 15 is a schematic diagram of the construction structure of the lower beam of the present invention, wherein standard joint flanges are respectively disposed at two ends of the standard joint.

Figure number and name: 1. the steel pipe buttress, 2, sand box, 3, guardrail, 4, bent cap, 5, wood truss, 6, main beam, 7, secondary beam, 8, main ridge, 9, secondary ridge, 10, support foundation, 11, pier stud, 12, double-spliced section steel, 13, U-shaped clamp, 14, steel pipe buttress top flange, 15, double-nut, 16, sand box bottom flange, 17, sand box top flange, 18, bottom section pre-embedded steel plate, 19, steel pipe buttress bottom flange, 20, clamping plate, 21, bottom beam, 22 and three-spliced section steel.

Detailed Description

The structure and use of the present invention will now be further described with reference to the accompanying drawings. As shown in fig. 1-15, the main body of the steel pipe support is a steel pipe buttress 1 and a profile steel support, a pier stud 11 is cast in situ by a profile steel support upper template at the top of the steel pipe buttress to form a capping beam 4, and the capping beam and the pier stud are connected into a whole by reinforced concrete; the bottom of steel pipe buttress is equipped with support basis 10 respectively, and the top of steel pipe buttress is equipped with girder 6, and the top of girder is equipped with secondary beam 7, main stupefied 8, inferior stupefied 9, template in proper order, and the both sides of girder are equipped with guardrail 3. The concrete structure is as follows: the girder is equipped with sand box 2 with the junction of steel pipe buttress, the upper strata of sand box is C40 concrete, the lower floor of sand box is well coarse sand, the upper strata of sand box sets up in the interior steel pipe of sand box top ring flange 17 bottom, the top surface of C40 concrete and the top surface parallel and level of interior steel pipe, well coarse sand sets up in the outer steel pipe of sand box bottom ring flange 16, the interior steel pipe of sand box top ring flange is in the outer steel pipe of sand box bottom ring flange in the upside down, the outer steel pipe one side bottom of sand box bottom ring flange is equipped with the bolt and seals, the bolt hole that the bolt sealed the department is equipped with the bolt. The sand box bottom flange plate is arranged on a steel pipe buttress top flange plate 14 at the top of the steel pipe buttress, double-spliced section steel 12 is arranged at the top of the sand box top flange plate, and a U-shaped clamp 13 penetrates through bolt holes of the sand box top flange plate, bolt holes of the sand box bottom flange plate and bolt holes of the steel pipe buttress top flange plate downwards in sequence after sleeving the section steel of the girder from two sides of the upper part of the girder and fixes the girder, the double-spliced section steel, the sand box and the steel pipe buttress top flange plate into a whole through double nuts 15, wherein the U-shaped clamp is a U-shaped.

Meanwhile, the bottom section of the steel pipe buttress is lengthened through the standard section, the bottom section is arranged on the support foundation, the bottom section embedded steel plate 16 of the bottom section is arranged on the support foundation, the bottom section embedded steel plate is provided with a steel pipe buttress bottom flange 19, the steel pipe buttress bottom flange is welded and fixed with the bottom section embedded steel plate through a clamping plate 20, and the clamping plate is L-shaped. The support foundation of the steel pipe buttress is provided with a cast-in-place bar foundation, a foundation embedded steel plate is arranged in the bar foundation, the bottom of the foundation embedded steel plate is provided with C12 anchoring steel bars, and the arrangement distance is 20 cm; the top of the bearing platform of the strip foundation is provided with a steel pipe, the bottom elevation of the steel pipe is-26 m, the top of the steel pipe is fixedly connected by adopting a horizontal brace and an inclined brace, the top of the steel pipe is provided with an H-shaped steel carrying pole beam along the bridge direction, the two rows of steel pipes in the middle are provided with double-spliced H-shaped steel carrying pole beams, the rest are provided with single carrying pole beams, and the top of the carrying pole beam is provided with a triple-spliced H-shaped steel bearing beam along the bridge direction. A lower cross beam 21 with rails built together is arranged below some cover beams, steel pipe buttresses below the beam tops of the lower cross beams are welded steel pipe buttresses, and the welded steel pipe buttresses are connected with standard joints of the steel pipe buttresses through steel pipe buttress top flange plates; the joint is provided with a three-spliced section steel 22 which is a three-spliced 32a I-shaped steel tie beam, and steel pipe buttress top flange plates on two sides of the three-spliced section steel are fixed into a whole through the U-shaped clamp 13 and the double nuts 15. The bent cap cantilever section at the bottom of the partial template is provided with a triangular wood truss, or the bent cap at the middle section of the pier stud is provided with a trapezoidal wood truss for further fixing the template at the bottom of the upper door type bent cap supported by the section steel.

The bent cap of this construction object mostly is gate-type bent cap and the support height all is higher, therefore the bent cap support adopts the steel pipe support method, adopts the form that steel pipe buttress and shaped steel support combine to be under construction promptly. The concrete structure of this steel pipe support is as follows:

1. a support foundation: the method is characterized in that a form of filling 60cm pond residues after undisturbed soil treatment and combining with a cast-in-place strip foundation is adopted, the cast-in-place strip foundation is arranged in the transverse bridge direction according to the position of a steel pipe buttress, and 2 steel pipes are arranged on each foundation. The length of the cast-in-place strip foundation is 3.7m, the height of the cast-in-place strip foundation is 0.8m, and C30 concrete is poured. The width of the cover beam cast-in-place strip foundation is 1.2 m; the width of the bent cap strip-shaped foundation is 1.5 m; the width of the bent cap strip-shaped foundation is 2m, and reinforcing bars are arranged in the beam body. And (3) before construction, after filling of the pond slag, taking one most unfavorable pond slag layer to perform a foundation bearing capacity test, wherein the actual bearing capacity of the pond slag layer is obtained through the test. If the construction requirements cannot be met, the method of increasing the thickness of the concrete to enlarge the stress area of the slag layer is adopted for reinforcement, and the actual bearing capacity of the slag layer of the pool is ensured to meet the construction requirements. The No. 45-50 bent cap is located in the current road area, the foundation bottom is the current asphalt road pavement, the bearing capacity can meet the construction requirement, and a foundation bearing capacity test is not needed. The bearing platform is partially arranged in the river channel, the whole section of the river channel cannot be backfilled according to the requirements of a water conservancy department, and the stability and compactness of a partial backfilling pond slag side slope cannot be guaranteed, so that the steel pipe piles are arranged in the bearing platform and on two sides of the bearing platform in a foundation mode. 12 steel pipes are arranged at the top of the bearing platform, 4 steel pipes are arranged at the outer side of the bearing platform, the steel pipes are phi 609 multiplied by 6mm steel pipes, the elevation of the pile top is the same as that of the current terrace, the elevation of the pile bottom of the steel pipe pile at the outer side of the bearing platform is-26 m, and the specific position is shown in the attached drawing in detail.

2. Steel pipe buttress: the steel pipe buttress adopts phi 377 multiplied by 6mm steel pipes, in order to facilitate the installation of the steel pipes, four steel pipes are combined to form a shaped standard section, and standard sections are connected by a standard section flange plate. The standard section flange plates are 14mm in thickness and 56cm in diameter, eight triangular steel plate stiffening plates are arranged at the joints of the standard section flange plates and the steel pipe buttress, and eight 8.8-grade M24 high-strength bolts are adopted for connecting each standard section flange plate. The steel pipe shaping standard knot plane is square arrangement, and adjacent steel pipe center distance is 2.5m, adopts double pin 8# channel-section steel to set up the level and props around. The height of the standard section is divided into two specifications of 4m and 6m, two horizontal supports are arranged at the position 60cm inward from the top and the bottom of the standard section of 4m, and three horizontal supports are arranged at the position 50cm inward from the top and the bottom and at the position 3m in the middle of the standard section of 6 m. And a 14# channel steel is adopted between the two horizontal braces to arrange the diagonal braces, and the directions of the adjacent diagonal braces are opposite.

3. Sand box: in order to facilitate the dismantling of the support after the concrete pouring is finished, a sand box is arranged at the top of the steel pipe buttress, and the height of the sand box is 0.38 m.

4. Main beam: the pier main beam is made of three-spliced 32a I-shaped steel, the other bent cap main beams are made of double-spliced 32a I-shaped steel, and the I-shaped steel main beams are arranged on the upper part of the sand box along the bridge direction.

5. Secondary beam: the secondary beam is divided into a plurality of forms according to different use positions. The main piers are separated double-column piers, the clear distance between the double columns is only 3.1m, only one standard steel pipe buttress can be placed, and the span is 2.5m, so that the secondary beam adopts H-shaped steel with the thickness of 350X 170X 6X 7 mm. The H-shaped steel secondary beam is only arranged between the separated double-column pier columns, and is transversely arranged on the upper portion of the main beam in the bridge direction, and the distance is 35 cm. And the secondary beams at the bottoms of the capping beams at the other positions are made of 32a or 40b I-steel and are arranged in the transverse bridge direction at the upper part of the main beam, and the time interval of the secondary beams made of 32a I-steel is 35cm and the time interval of the secondary beams made of 40b I-steel is 60 cm. The load of the operation platform at two sides is small, and the distance from the edge of the cover beam to the edge of the operation platform is about 2.7m-2.825m, so that two H-shaped steel secondary beams with the length of 350 multiplied by 170 multiplied by 6 multiplied by 7mm are arranged at the position of the operation platform, and the distance is not more than 150 cm.

6. Main corrugation: the main beam is made of 10# I-steel and arranged on the upper portion of the secondary beam along the bridge direction. The height of the bent cap beams is higher, the distance between the main ridges is set to be 40cm, and the distance between the main ridges of the rest bent caps is 50 cm.

7. Secondary corrugation: the bent cap part is the gate-type bent cap, and the part is a word bent cap, and bent cap cantilever section sets up triangular wood truss, or pier stud interlude bent cap sets up trapezoidal wood truss. The beam bottom of the door type bent cap is horizontal, 9 multiplied by 9 is used as a secondary ridge, and the distance between the secondary ridges is 20 cm; a word bent cap all has the chamfer at the intercolumniation and both sides cantilever end, consequently adopt 8# channel-section steel preparation design truss as the horizontal stupefied of template, it is triangle-shaped and trapezoidal to stereotype inferior stupefied, upper strata and lower floor are 8# channel-section steel, bent cap both sides cantilever end wooden truss intermediate strut adopts 8# channel-section steel, all the other bent cap truss intermediate struts adopt C32 deformed steel bar, interval 60cm, bent cap truss interval is not more than 50cm, in the bridge direction again, two-layer 9 is placed to the cross bridge in bent cap truss top, interval 20 cm.

8. Template: the templates are made of 15mm thick bottom template bamboo plywood, are fully laid and arranged, and are fixed with the secondary ridges.

The steel pipe support comprises the following steps of:

1. construction of a strip foundation: the cast-in-place strip foundation is arranged along the bridge direction according to the position of the steel pipe buttress, C30 concrete is poured, and reinforcing bars are arranged inside the beam body. For the convenience of fixing the upper steel pipe buttress after installation, a foundation embedded steel plate is arranged in the strip foundation corresponding to the position of the steel pipe, and the plane size of the foundation embedded steel plate is 75 multiplied by 75cm and the thickness of the foundation embedded steel plate is 8 mm. C12 anchoring steel bars are arranged at the bottom of the foundation embedded steel plate, and the arrangement distance is 20 cm; after the foundation embedded steel plate is installed, the surface level is ensured, and the subsequent steel pipe buttress installation is facilitated.

2. Constructing a steel pipe foundation: twelve steel pipes are arranged at the top of a bearing platform of the strip foundation, six steel pipes are arranged on the south and north sides of the pier stud, two steel pipe piles are arranged on the east and west sides of the bearing platform, the elevation of the bottom of each steel pipe is-26 m, and the tops of the steel pipes are fixedly connected by adopting horizontal braces and inclined braces. The top of the steel pipe is provided with a 600X 200X 15X 8mm H-shaped steel carrying pole beam along the bridge direction, the middle two rows of steel pipes are provided with double-spliced H-shaped steel carrying pole beams, and the rest steel pipes are provided with single carrying pole beams; the transverse bridge at the top of the shoulder pole beam is provided with an H-shaped steel bearing beam with the diameter of 600 multiplied by 200 multiplied by 15 multiplied by 8mm which is spliced in three.

3. Installing a steel pipe buttress: the standard section of the steel pipe buttress is installed by adopting a 25-t truck crane in a matching way, the dead weight of the standard section of the 6m steel pipe buttress is about 2.4t, the lifting capacity of the 25t truck crane is 4.8t when the working radius is 9m and the longest suspension arm is 31.5m, and the construction requirement can be met by adopting the 25t truck crane in a matching way. The steel pipe buttresses are arranged according to the number of trusses, one truss is supported from the bottom of the cover beam to a group of standard steel pipe joints of the strip-shaped foundation, and the central distance between every two trusses is not more than 7.5 m.

a) And mounting a bottom section: the bottom section of the steel pipe buttress is arranged at a bottom section embedded steel plate arranged on the support foundation, and a flange plate at the bottom of the steel pipe buttress is closely attached to the bottom section embedded steel plate. After the steel pipe buttress of the first section is installed in place, in order to ensure the stability of the steel pipe buttress, a clamping plate is welded and fixed at the position of a flange plate at the bottom of the steel pipe buttress and a bottom section embedded steel plate; the clamping plate is L-shaped, and is welded and fixed with the bottom section embedded steel plate after the flange plate at the bottom of the steel pipe pier is tightly pressed.

b) And standard joint extension installation: and the standard section is installed by adopting the cooperation of a 25t truck crane, after the standard section is hoisted in place, the bolt holes of the steel pipe buttress top flange plates are fixedly connected by adopting 8.8-grade M24 high-strength bolts, and each steel pipe buttress top flange plate is provided with eight high-strength bolts. In order to facilitate the installation of the standard section of the steel pipe buttress and the installation of the flange plate bolt at the top of the steel pipe buttress, a construction operating platform is arranged 1.3m below the top in the standard section, and the width of the operating platform is 0.7 m. Meanwhile, the vertical steel ladder stand is arranged from the bottom of the standard section to the operating platform, so that the personnel can conveniently mount and follow-up check up and down, and the annular protective covers are arranged on two sides of the ladder stand, so that the safety of the personnel from top to bottom is ensured.

c) Installing a steel pipe support top adjusting section: the elevation of the bottom of the bent cap is different from that of the original terrace, so that the top of the steel pipe support is adjusted by adopting an independent steel pipe adjusting section, and the elevation of the top of the support is ensured to be consistent with the elevation of the bottom of the designed bent cap. The specification of the steel pipe at the independent steel pipe adjusting section is the same as that of the standard section, and a phi 377 multiplied by 6mm steel pipe is adopted. In order to be connected with the standard section conveniently, two ends of the adjusting section are provided with steel pipe buttress top flange plates which are connected with the standard section through the steel pipe buttress top flange plates. After the upper adjusting section of one standard joint is installed, horizontal supports are arranged at the positions which are 30cm inward respectively at the two ends of the adjusting section. When the height of the adjusting section is less than 1m, no inclined strut is arranged; when the height of the adjusting section is larger than 1m, a 14# channel steel is adopted between two horizontal struts to form an inclined strut, and the directions of adjacent inclined struts are opposite.

d) The lower cross beam adjusting section: and the track co-construction section is provided with a track beam and a lower cross beam, the lower cross beam at the lower part of the bent cap is constructed firstly, and then the upper bent cap is constructed under the projection plane of the upper bent cap. Therefore, standard sections of the steel pipe buttresses cannot be adopted below the beam top of the lower cross beam, the steel pipe buttresses are welded on site, the distance between centers of steel pipes in the forward bridge direction is 3.2m, and the distance between centers of steel pipes in the transverse bridge direction is still 2.5 m. Because the beam width of the lower cross beam is 2.5m at the widest, the center distance between adjacent steel pipes of the standard section of the steel pipe buttress is 2.5m, and the standard section of the steel pipe buttress cannot be adopted in the beam area of the lower cross beam. Therefore, the steel pipe buttresses are welded on site in the range of the lower cross beam, the distance between the steel pipes of the welded steel pipe buttresses and the center of the steel pipe is 3m along the bridge, the clear distance between the steel pipes is about 2.62m and is larger than the width of the lower cross beam by 2.5m, the installation requirement is met, the distance between the steel pipes and the beam body of the lower cross beam is smaller, and the steel pipes and the lower cross beam are wedged into a wood wedge to be clamped and fixed after the installation is finished. Meanwhile, the distance between the transverse bridge and the middle of the steel pipe is the same as that of a standard joint, 2.5m is still adopted, a horizontal support is arranged at the position 20cm outside the top and the bottom of the lower crossbeam respectively, and a horizontal inclined support is arranged on the north and south sides of the lower crossbeam respectively, and the directions are opposite. The horizontal support and the cross support installation between the steel pipe buttresses at the part below the top and the bottom of the lower beam are the same as the standard section installation method.

4. Manufacturing a sand box: in order to facilitate the dismantling of the support after the concrete pouring is finished, a sand box is arranged at the top of the steel pipe buttress, the height of the sand box is 0.38m, and the sand box is formed by filling dry medium-coarse sand in the outer steel pipe. The outer steel pipe of the sand box adopts a seamless steel pipe with the diameter of 406 multiplied by 8mm and the height of 25cm, the bottom plate steel plate adopts a flange plate which is the same as the steel pipe buttress so as to be convenient for the connection of the steel pipe buttress, and the bottom plate steel plate is fixedly welded with the outer steel pipe. The outer steel pipe is provided with a circular bolt hole 20mm away from the bottom plate, and the bolt is screwed in for being used as a sand unloading outlet when the support is detached. The inner steel pipe of the sand box is a phi 377 multiplied by 8mm steel pipe with the height of 20cm, the top plate steel plate is a flange plate which is the same as the steel pipe buttress, and the top plate steel plate and the inner steel pipe are welded and fixed. The inner steel pipe and the top steel plate thereof are used as templates and are inverted, C40 concrete is poured into the inner steel pipe, and the inner steel pipe is placed on a test vibration table to be vibrated and compacted. The top surface of the concrete is flush with the top surface of the inner steel pipe, the upper surface of the concrete is smoothed by a trowel, and the cylindrical top surface of the manufactured C40 concrete is covered, sprinkled and maintained. The bottom plate steel plate of the sand box is a flange plate which is the same as the steel pipe buttress, and the inner steel pipe is inverted and is attached to the outer steel pipe, so that the sand box is fixed with the steel pipe buttress by adopting double nuts after the installation is finished; two bolt holes that reserve horizontal symmetry during two nut installations do not install two nuts for follow-up girder is fixed to be used. The top plate steel plate is a sand box top flange plate, and the bottom plate steel plate is a sand box bottom flange plate.

5. Main beam installation: the main beams are made of 32a multi-spliced I-shaped steel and are arranged on the upper portion of the sand box along the bridge direction, namely two steel pipe buttress standard sections are arranged on the upper portion of each steel pipe buttress standard section, and the main beams are installed by adopting 25t truck crane matching. The length of the I-shaped steel is 6m, the beam width of the cast-in-place bent cap is 2.2m-3.1m, the distance between the steel pipes is 2.5m, and the loads of the operation platforms on the two sides are small. Therefore, two double-spliced I-beams are arranged in a staggered mode, the double-spliced overlapping length is 3.5m, 2.5m of each double-spliced I-beam is a single I-beam, and the stress requirement of the double-spliced I-beams at the beam bottom can be met, and the width requirement of the construction platforms at the two sides can be met. And the double-spliced I-shaped steel lap joint area is fixed by spot welding, and four vertical stiffening ribs are arranged at the I-shaped steel web plate at the pier top position of the steel pipe buttress for ensuring the stress of the I-shaped steel, and the distance is 10 cm. The girder on both sides of the steel pipe buttress is respectively provided with a cantilever end with the width of 3m, and the girder needs to be fixed in order to prevent the section steel girder from overturning.

The U-shaped clamp is used for fixing, the U-shaped clamp is a U-shaped screw, the diameter of the U-shaped clamp is 24mm, reserved bolt holes of a sand box top flange plate, a sand box bottom flange plate and a steel pipe buttress top flange plate are utilized, the U-shaped clamp penetrates through bolt holes of the sand box top flange plate, bolt holes of the sand box bottom flange plate and bolt holes of the steel pipe buttress top flange plate downwards in sequence after steel sections of the girder are sleeved on two sides of the upper portion of the girder, and then the U-shaped clamp is fixed through double nuts, so that the purpose of fixing the steel girder is.

6. Secondary beam, main stupefied, inferior stupefied, template installation: adopting a 25t truck crane for matching installation, firstly installing secondary beam I-shaped steel, and fixing the secondary beam I-shaped steel and a main beam in a spot welding manner; after the installation is finished, installing a 10# I-steel main edge and a secondary edge; and finally, mounting a bottom die bamboo plywood, fully laying and arranging, and fixing with the secondary ridges. The main ridge is made of 10# I-steel, the length of the I-steel is 6m, the beam width of the cast-in-place bent cap is 2.85m-3.1m, and the loads of the operation platforms on the two sides are small. Therefore, the I-beams are arranged in a staggered mode, the distance between the beam bottoms is determined according to the arrangement of the vertical rods in the transverse bridge direction, and the distance between the I-beams on the working faces on the two sides is increased by 1 time.

7. Installation of personnel channels and guardrails: the main line bent cap is far away from the ground, the personnel upper and lower channels are made of steel independent pedestrian channel ladder cages with the height of 2m, the width of 1.5m and the length of 4m, the personnel upper and lower channels are assembled by matching with a field crane, the longitudinal and transverse directions and the space between each section of ladder cage are connected by phi 20 bolts, and an upper ladder and a lower ladder are arranged in each section of ladder cage. After the support is erected, a guardrail is arranged at the position, close to the edge, of the main beam, steel pipes are erected, and the bottoms of the steel pipes are welded and fixed with the No. 10I-steel. The height of the guardrail rod is 1.2m, three cross rods are adopted, the bottom of the guardrail is provided with a 180mm foot baffle plate, the surfaces of the guardrail and the foot baffle plate are brushed with red and white warning colors, warning marks are arranged, and the steel pipe support can be installed.

The acceptance steps of the steel pipe support are as follows: after the steel pipe support is erected, the following aspects of acceptance check are carried out according to the erection scheme: 1. checking whether the materials used by the bracket are consistent with the scheme description; 2. checking whether the connection mode of each node of the section steel support meets the requirement of a scheme; 3. checking whether the distance between the main beam, the secondary beam and the main ridge meets the requirement of a scheme; 4. checking whether the edge guardrails on the bent cap formwork are firm and reliable and whether the upper and lower channel ladder cages are installed in place; 5. and after the construction of the support is finished, the construction unit carries out self-inspection. And after the self-inspection is qualified, informing the owner and the supervision unit to check and accept. After the acceptance is qualified, the next procedure of construction can be carried out.

The steel pipe support dismantling method comprises the following concrete steps: the main line bent cap is of a prestressed structure, so that the support is dismantled after the prestressing force is applied and the hole grouting construction is completed. The support is dismantled in the reverse process of support installation, and the support is dismantled in a mode that a 25t truck crane is matched with manpower according to a dismantling principle of 'from top to bottom and symmetry at two sides'. When the device is disassembled, medium coarse sand in the lower sand boxes of the main beams along the bridge is removed by opening the bolts at one side of the inner steel pipes, so that the bottoms of the template and the cover beam are empty, and the sand boxes under the same main beam need to be removed synchronously; sequentially removing the template, the secondary ribs, the main ribs and the secondary beams from top to bottom after the support and the capping beam bottom die are hollowed; then, removing the main beam after removing the fixed U-shaped clamp, and removing the sand box after screwing off double nuts of the sand box; and after the section steel support is dismantled, dismantling the steel pipe buttress, and chiseling the ground strip foundation after dismantling all the steel pipe buttress. The steel pipe buttress is removed because the steel pipe buttress is positioned below the projection surface of the cover beam, and therefore, a 25t truck crane is respectively parked at the south and north sides of the cover beam, and the standard section of the steel pipe buttress is removed in a double-machine matching mode; the two truck cranes respectively hoist the south and north sides of the standard section, and after the steel wire ropes are properly tightened, the bolts connected with the lower section of steel pipe are dismantled; and then, two truck cranes are matched to slowly lift the standard section to separate the standard section from the lower steel pipe buttress, the demolished standard section is horizontally moved to the middle of the standard section of the two steel pipe buttresses, and then the standard section is slowly lowered to the ground to finish demolishing the standard section. And chiseling the ground strip foundation after all the steel pipe buttresses are removed according to the steel pipe buttress removing steps.

The above contents are intended to illustrate the technical means of the present invention, and do not limit the technical scope of the present invention. Obvious modifications to the invention, combined with the prior common general knowledge, will be apparent to those skilled in the art and still fall within the scope of the claims of the invention.

Claims (6)

1. A cast-in-place bent cap assembled steel pipe support comprises a main body of the steel pipe support, wherein a steel pipe buttress (1) and a profile steel support are arranged, a bent cap (4) is formed by casting a pier stud (11) in place through a profile steel support upper template at the top of the steel pipe buttress, and the bent cap and the pier stud are connected into a whole through reinforced concrete; the bottom of the steel pipe buttress is provided with a support foundation (10) respectively, the top of the steel pipe buttress is provided with a main beam (6), the top of the main beam is provided with a secondary beam (7), a main ridge (8), a secondary ridge (9) and a template in sequence, and two sides of the main beam are provided with guardrails (3); the steel pipe pier is characterized in that a sand box (2) is arranged at the joint of a main beam (6) and a steel pipe pier (1), the upper layer of the sand box is C40 concrete, the lower layer of the sand box is medium coarse sand, the upper layer of the sand box is arranged in an inner steel pipe at the bottom of a sand box top flange (17), the top surface of C40 concrete is flush with the top surface of the inner steel pipe, the medium coarse sand is arranged in an outer steel pipe of a sand box bottom flange (16), the inner steel pipe of the sand box top flange is arranged in the outer steel pipe of the sand box bottom flange in an inverted mode, the sand box bottom flange is arranged on the steel pipe pier top flange (14) at the top of the steel pipe pier, double-spliced section steel (12) is arranged at the top of the sand box top flange, U-shaped clamps (13) sequentially penetrate through bolt holes of the sand box top flange, bolt holes of the sand box bottom flange and bolt holes of the steel pipe pier, The double-spliced steel, the sand box and the steel pipe buttress top flange are fixed into a whole, and the U-shaped clamp is a U-shaped screw rod.

2. The cast-in-place bent cap assembled steel pipe support according to claim 1, characterized in that the bottom of one side of the outer steel pipe of the sand box bottom flange (16) is provided with a bolt seal, and a bolt hole at the bolt seal is provided with a bolt.

3. The cast-in-place bent cap assembled steel pipe support of claim 1, characterized in that the bottom section of the steel pipe buttress (1) is lengthened through a standard joint, the bottom section is arranged on the support foundation (10), the bottom section embedded steel plate (18) of the bottom section is arranged on the support foundation (10), the bottom section embedded steel plate is provided with a steel pipe buttress bottom flange (19), the steel pipe buttress bottom flange is welded and fixed with the bottom section embedded steel plate through a clamping plate (20), and the clamping plate is L-shaped.

4. The cast-in-place bent cap assembled steel pipe support frame of claim 1, characterized in that the standard section of the steel pipe buttress (1) is provided with standard section flange plates at the ends of four steel pipes respectively, the standard section is connected with the standard section through the standard section flange plates and high-cavity bolts, the joint of the standard section flange plates and the steel pipe buttress is provided with a triangular steel plate stiffening plate, and a horizontal support and an inclined support are arranged between the top and the bottom in the standard section; the steel pipe buttress at the top of the stair is provided with a construction operation platform, and the stair are arranged in the standard knot.

5. The cast-in-place bent cap assembly type steel pipe support frame of claim 1, wherein the support frame foundation (10) of the steel pipe buttress (1) is provided with a cast-in-place strip foundation, a foundation embedded steel plate is arranged in the strip foundation, and C12 anchoring steel bars are arranged at the bottom of the foundation embedded steel plate at an arrangement interval of 20 cm; the top of the bearing platform of the strip foundation is provided with a steel pipe, the bottom elevation of the steel pipe is-26 m, the top of the steel pipe is fixedly connected by adopting a horizontal brace and an inclined brace, the top of the steel pipe is provided with an H-shaped steel carrying pole beam along the bridge direction, the two rows of steel pipes in the middle are provided with double-spliced H-shaped steel carrying pole beams, the rest are provided with single carrying pole beams, and the top of the carrying pole beam is provided with a triple-spliced H-shaped steel bearing beam along the bridge direction.

6. The cast-in-place bent cap assembled steel pipe support frame of claim 1, characterized in that a lower cross beam (21) with a track built together is arranged below the bent cap (4), the steel pipe buttress (1) below the beam top of the lower cross beam is a welded steel pipe buttress, and the welded steel pipe buttress is connected with the standard joint of the steel pipe buttress through a steel pipe buttress top flange plate (14); the junction is equipped with three-piece shaped steel (22), and three-piece shaped steel is three-piece 32a I-steel tie beam, and the steel pipe buttress top ring flange of three-piece shaped steel both sides passes through U type card (13) with double nut (15) are fixed as an organic whole.

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