CN112045841A - Construction method of assembly type beam-making pedestal for prefabricating high-speed railway box beam - Google Patents

Abstract

The invention relates to a construction method of an assembled beam-making pedestal for prefabricating high-speed railway box girder, belonging to the technical field of high-speed railway box girder prefabrication. The method of the invention firstly performs waterproof protection construction on the existing roadbed, then hoists the prefabricated beam-making pedestal foundation on the roadbed, and finally performs prefabricated box girder work through the prefabricated beam-making pedestal foundation. The prefabricated beam-making pedestal foundation includes multiple beam-making pedestal monomers connected in sequence. The connecting ends of the adjacent two-section beam-making pedestal monomers are assembled and connected by a mortise and tenon structure, and the connecting part of the mortise and tenon structure is fixed with long rod bolts. connect. The construction method of the invention is green and environmentally friendly, the construction process is simple, the versatility is strong, and the popularization and practical value are high. The concrete components of the pedestal can be recycled and reused, which reduces energy consumption and has obvious economic effects. It can meet the specification requirements of railway box girder prefabrication, and does not require the pedestal structure itself to be strengthened. Design and construction of the pedestal foundation are energy-saving and environmentally friendly.

Description

Construction method of prefabricated beam-making pedestal for prefabricated high-speed railway box girder

technical field

The invention relates to the technical field of high-speed railway box girder prefabrication, in particular to a construction method for a prefabricated beam-making pedestal for prefabricating high-speed railway box girder.

Background technique

In 2019, 8,489 kilometers of new railway lines were put into operation across the country, including 5,474 kilometers of high-speed railways. In 2020, 26 projects and more than 4,000 kilometers of new lines will be opened, with bridges accounting for more than 45%. In the construction of high-speed railways in China, according to the distribution of lines and bridges, a prefabricated yard with a centralized prefabricated box girder should be arranged in the middle section of the bridge cluster or at both ends of the super bridge, and the maximum distance should not exceed 20km to 30km. There are more than 90 railway prefabricated box girders.

The civil construction of the prefabricated beam yard mainly includes the beam making pedestal and the static load test bench. Beam-making pedestals usually adopt well-type, wall-type or steel pier and concrete slab combination pedestals, and the foundation adopts pile foundation or raft foundation. No matter what kind of structure the precast pedestal adopts, its pedestal and foundation are all cast-in-place concrete. In each beam yard, only the prefabricated pedestal and foundation concrete cast-in ^- situ amount is more than 2000m3, and the concrete masonry structure cannot be recycled. After the prefabrication of the box girder is completed (generally, the prefabrication period is within 12 months), the prefabricated pedestal is directly demolished and discarded, and the beam yard is reclaimed. Every year, the prefabricated box girder of the high-speed railway only produces more than ^18,000m3 of concrete construction waste, which is a serious consumption and waste of concrete construction materials, and also increases the land for ballast abandonment. In addition, a large amount of dust and noise are generated during the removal process, and the environment is seriously polluted.

SUMMARY OF THE INVENTION

The invention is to solve the problem that the prefabricated pedestal and foundation of the high-speed railway box girder cannot be recycled, the waste of one-time use of concrete is serious, the amount of concrete masonry for the prefabricated pedestal structure is too large, the demolition and reclamation process of the beam yard causes serious damage to the environment, waste of land, etc. A series of problems are provided, and a construction method of a prefabricated beam-making pedestal for a prefabricated high-speed railway box girder is provided. This method is a construction method based on the concept of green, pollution-free and prefabricated buildings, and is especially suitable for the prefabricated construction of 900t box girder of 350Km high-speed railway.

The present invention is achieved through the following technical solutions:

A construction method for a prefabricated beam-making pedestal for a prefabricated high-speed railway box girder, comprising the following steps:

1) Carry out waterproof protection construction for the existing roadbed, specifically: first build a 5cm-thick water stable layer on the road surface, lay a layer of geomembrane on the water stable layer, lay a layer of geotextile on the geomembrane, and then lay a layer of geotextile on the geotextile. A layer of sand-free concrete is poured as the surface layer, and finally leveled;

2) Make the prefabricated beam-making pedestal foundation, and place the prefabricated beam-making pedestal foundation on the top surface of the constructed subgrade, and finally perform the prefabricated box girder work through the prefabricated beam-making pedestal foundation; among them, the prefabricated beam-making pedestal foundation The pedestal foundation includes a plurality of beam-making pedestal monomers connected in sequence, the connecting ends of the adjacent two-section beam-making pedestal monomers are assembled and connected by a mortise and tenon structure, and the connecting part of the mortise and tenon structure is fixedly connected by a long rod bolt.

Further, the beam-making pedestal monomer is a long-strip concrete structure formed by pouring into one piece, which is composed of a wide strip body at the lower part and a narrow strip body at the upper part, and its vertical cross-section is a "convex" shape; the beam-making pedestal monomer is divided into There are two types of exterior styles, one is the beam-making pedestal unit whose upper narrow strips at both ends are protruding outward, and the other beam-making pedestal unit is that the lower wide strips at both ends are protruding outward; two The beam-making pedestal units of various shapes are alternately connected adjacently in turn, and the protruding narrow strips and the protruding wide strips overlap each other to form a mortise and tenon structure and are fixedly connected by long rod bolts.

Further, on the single body of the beam-making pedestal, the protruding narrow strip body and the protruding wide strip body are provided with embedded pipes for the long rod bolts to be inserted, and the protruding narrow strip body and the protruding wide strip body are provided with embedded pipes. After overlapping each other, the pre-embedded pipes on the two are connected and connected, and the long rod bolts are inserted into the butted pre-embedded pipes to connect and fix the two.

Further, the production method of the beam-making pedestal monomer includes the following steps: 1) Forming: firstly, the template is polished and cleaned, and then the template is assembled, and the size error after the template is controlled to be within 1cm after assembly. Check it diagonally, and apply mold release agent after the template is assembled; 2) Reinforcing bar binding: The bar binding should ensure the blanking size of the semi-finished steel bar, and the deviation should be controlled within 2cm. Less than 1cm; 3) Installation of pre-embedded parts: the installation error of the anchor bolt reserved hole and sleeve shall be within 1cm, and the allowable error of the pre-embedding of the hanger and hanger is 2cm; Tight, if the formwork gap is too large, adjust the formwork, if it is a structural gap, use foam glue to seal it to prevent leakage during the concrete pouring process; the pouring process is strictly vibrated according to the requirements, so as to achieve fast insertion and slow extraction, and vibration points are divided into parts. Evenly, the time of each vibration is 20s ~ 30s, when the concrete no longer sinks significantly, bubbles do not appear, and the grouting starts; 5) Precast component maintenance: After the concrete is poured, cover it with geotextile or plastic film, sprinkle with water Maintenance, keep the concrete surface moist; 6) Demoulding: check the strength of the concrete according to the notice of the laboratory, and prevent the formwork from colliding with the concrete to cause missing edges and corners; 7) Finished product inspection: use a tape measure to detect the length and size of the prefabricated components, use A spirit level and a feeler gauge are used to detect the flatness of components.

The construction method of the prefabricated beam-making pedestal used for the prefabricated high-speed railway box girder of the present invention, the key technical basis of which is the assembled and reusable beam-making pedestal foundation. During transportation, the single structure of the beam-making pedestal that forms the foundation of the beam-making pedestal is small, which is convenient for transportation; during construction, the multi-section beam-making pedestal monomers are sequentially assembled and connected to the length of the beam-making pedestal foundation through long rod bolts, which is fast and convenient, and is convenient for on-site installation. It can be installed quickly, and the straightness of the lower beam-making pedestal unit can be adjusted depending on the connection method of the embedded pipe and the long rod bolt, without the need to borrow other equipment, and the adjustment is fast. After the foundation construction of the girder pedestal is completed, the prefabrication of the high-speed railway box girder can be carried out. After the final construction is completed, the foundation of the beam-making pedestal can be dismantled. When dismantling, only the long rod bolts are pulled out, and the beam-making pedestal foundation can be divided into several individual beam-making pedestal units for subsequent reuse.

Compared with the prior art, the present invention has the following beneficial effects:

The construction method of the invention is green and environmentally friendly, the construction process is simple, the versatility is strong, and the popularization and practical value are high. The concrete components of the pedestal can be recycled and reused, which reduces energy consumption and has obvious economic effects. It can meet the specification requirements of railway box girder prefabrication, and does not require the pedestal structure itself to be strengthened. Design and construction of the pedestal foundation are energy-saving and environmentally friendly.

Description of drawings

The accompanying drawings here are used to provide further descriptions of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

FIG. 1 is a schematic structural diagram of an assembled beam-making pedestal foundation in the method of the present invention.

FIG. 2 is a top view of FIG. 1 .

FIG. 3 is a schematic structural diagram of an exterior style of a beam-making pedestal unit in the method of the present invention.

FIG. 4 is a top view of FIG. 3 .

FIG. 5 is a schematic structural diagram of another exterior style of the beam-making pedestal unit in the method of the present invention.

FIG. 6 is a top view of FIG. 5 .

FIG. 7 is a vertical cross-sectional view of a beam-making base unit in the method of the present invention.

FIG. 8 is a schematic diagram of the connection and fixation of the beam-making pedestal monomers of two shapes in the method of the present invention.

In the picture: 1-beam-making pedestal monomer, 1-1-wide strip body, 1-2-narrow strip body, 2-long rod bolt, 3-pre-embedded pipe.

Detailed ways

In order to make those skilled in the art better understand the present invention, the present invention will be further clearly and completely described below with reference to the accompanying drawings and the embodiments. It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

As shown in Figures 1 to 8, a construction method for a prefabricated beam-making pedestal for a prefabricated high-speed railway box girder includes the following steps:

1) Carry out waterproof protection construction for the existing roadbed, specifically: first build a 5cm-thick water stable layer on the road surface, lay a layer of geomembrane on the water stable layer, lay a layer of geotextile on the geomembrane, and then lay a layer of geotextile on the geotextile. A layer of sand-free concrete is poured as the surface layer and finally leveled.

2) Make the prefabricated beam-making pedestal foundation, and place the prefabricated beam-making pedestal foundation on the top surface of the constructed subgrade, and finally perform the prefabricated box girder work through the prefabricated beam-making pedestal foundation; among them, the prefabricated beam-making pedestal foundation The pedestal foundation includes a plurality of beam-making pedestal monomers 1 connected in sequence, the connecting ends of the adjacent two-section beam-making pedestal monomers 1 are assembled and connected by a mortise and tenon structure, and a long rod bolt 2 is used for the fixed connection in the connection part of the mortise and tenon structure. . The beam-making pedestal unit 1 is a long-striped concrete structure cast as one piece, consisting of a wide strip body 1-1 in the lower part and a narrow strip body 1-2 in the upper part, and its vertical section is a "convex" shape; the beam-making pedestal The unit 1 is divided into two exterior styles, one is the beam-making base unit 1, the upper narrow strips 1-2 at both ends are protruding outward, and the other beam-making base unit 1 is the lower part of the two ends. The wide strip body 1-1 is protruding outward; the beam-making pedestal units 1 of the two shapes are alternately connected adjacently in turn, and the protruding narrow strip body 1-2 and the protruding wide strip body 1-1 overlap each other. It is connected to form a mortise and tenon structure and is fixedly connected by long rod bolts 2, specifically: the protruding narrow strip body 1-2 and the protruding wide strip body 1-1 are provided with pre-embedded pipes for the long rod bolts to be inserted through. 3. After the protruding narrow strip body 1-2 and the protruding wide strip body 1-1 are overlapped with each other, the pre-embedded pipes 3 on the two are butt-connected and the long rod bolts 2 are inserted into the butted pre-embedded pipes 3. Connect the two inside. Using the connection and fixing method of long rod bolts 2 and pre-embedded pipes 3 can not only control the height of the foundation in elevation, but also control the straightness of the foundation.

The manufacturing method of the beam-making pedestal monomer comprises the following steps:

1) Formwork: first grind and clean the formwork, and then assemble the formwork. After the formwork is assembled, the size error is within 1cm, and the inspection is carried out by measuring the length, width and diagonal angle. After the formwork is assembled, paint and demould. agent;

2) Binding of steel bars: The binding of steel bars should ensure the cutting size of semi-finished steel bars, and the control deviation should be within 2cm. After the steel bars are bound, the deviation of the binding position should be controlled, and the control deviation should be less than 1cm;

3) Installation of embedded parts: the installation error of anchor bolt embedded pipe 3 is within 1cm, and the allowable error of pre-embedded hanging nails is 2cm;

4) Concrete pouring: Check the size of the formwork before concrete pouring, and the formwork is required to be tightly closed. If the gap between the formwork is too large, adjust the formwork. If it is a structural gap, use foam glue to seal it to prevent leakage during concrete pouring. It is required to vibrate, so that it can be inserted quickly and pulled out slowly, and the vibration points are evenly distributed. The time of each vibration is 20s to 30s, and the time when the concrete no longer sinks significantly, does not appear bubbles, and starts to splatter shall prevail;

5) Precast component maintenance: After the concrete is poured, cover it with geotextile or plastic film, sprinkle water for maintenance, and keep the concrete surface moist;

6) Demoulding: Check the strength of the concrete according to the notification from the laboratory, and prevent the formwork from colliding with the concrete and causing missing edges and corners when demoulding;

7) Finished product inspection: use a tape measure to detect the length of the prefabricated components, and use a level and feeler gauge to detect the flatness of the components.

In the specific implementation, the length of a prefabricated beam-making pedestal foundation is 33.7m and the width is 1m, and three prefabricated beam-making pedestal foundations are arranged side by side for the construction of box girder prefabrication. For each prefabricated beam-making pedestal foundation, ten pieces of beam-making pedestal monomers 1 are assembled, including eight beam-making pedestal monomers 1 with a size of 4×1×0.6m and a size of 3.1×1×0.6 There are two beam-making pedestal units 1 of m, of which, the two beam-making pedestal units 1 with a size of 3.1×1×0.6m are located at both ends of the entire prefabricated beam-making pedestal foundation, and the beam-making pedestal unit 1 at the end is located at both ends. The wide strip body 1-1 and the narrow strip body 1-2 of the beam pedestal unit 1 are aligned; the weight of the single beam-making pedestal unit 1 is controlled within 6t, which is convenient for on-site hoisting operations, and the beam-making pedestal unit 1 is hoisted and spliced , using the mortise and tenon lap joint structure between the beam-making pedestal monomers 1, the long rod bolts 2, and the pre-embedded pipes 3 to fix the adjacent beam-making pedestal monomers 1, specifically: the upper and lower beam-making pedestal monomers 1 are adopted The mortise and tenon lap joint is used for connection, the length of the lap joint structure is 50cm, and a Φ50 embedded pipe 3 is reserved at the lap joint for anchoring the long rod bolt 2.

During the prefabrication of box girder, the above-mentioned reusable prefabricated girder pedestal foundation is used in the same way as the conventional girder pedestal foundation, and can carry concrete support pressure and accessories such as steel formwork and support plate; after the completion of box girder prefabrication construction , it is necessary to dismantle the foundation of the assembled beam-making pedestal. When dismantling, just pull out the long rod bolts 2, and the single-piece beam-making pedestal 1 can be reused.

Compared with the current domestic traditional prefabricated beam pedestal, the present invention has obvious advantages: first, the prefabricated beam pedestal foundation is matched and prefabricated in advance, which shortens the construction period of the prefabricated beam yard (at least 28 days); second, the prefabricated beam pedestal foundation can be Factory prefabrication can also be closed and prefabricated on site, the finished product is of good quality, and the process is environmentally friendly; third, the base structure of the prefabricated beam pedestal is simple, and the production and installation process is simple; fourth, the foundation of the prefabricated beam pedestal can be recycled and used, which is economical Good, reduce the generation of concrete construction waste, do not need to increase the waste land for disposal of waste waste, energy saving, green, land saving and environmental protection; Fifth, the basic structure size of the prefabricated beam-making pedestal is further optimized, each pedestal reduces concrete by 95m ³ , and the economy is high. Material saving and energy saving; Sixth, in the process of reclamation of prefabricated beam yard, the foundation of the prefabricated beam-making pedestal can be hoisted and dismantled, without the need for a large breaking hammer to break it down, the demolition process is free of noise and dust pollution, and the construction process is environmentally friendly; Seventh, the prefabricated beam-making pedestal The bearing capacity of the foundation foundation can reach 300Kpa. On the basis of the traditional prefabricated pedestal foundation treatment, there is no need to further strengthen the foundation treatment, the site requirements are not high, and the applicability and versatility are strong; Eighth, the prefabricated beam pedestal foundation can be used in new railway stations. Or it can be assembled and used on the subgrade of the interval to further save the land for the railway box girder prefabricated beam field.

The embodiments are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims (4)

1. A construction method for an assembly type beam-making pedestal for prefabricating a high-speed railway box beam is characterized by comprising the following steps:

1) carry out water protection construction to existing road bed, specifically do: firstly, a 5 cm-thick water stabilization layer is constructed on a road surface, a layer of geomembrane is laid on the water stabilization layer, a layer of geotextile is laid on the geomembrane, a layer of sand-free concrete is poured on the geotextile to be used as a surface layer, and finally, leveling is carried out;

2) manufacturing an assembly type beam-making pedestal foundation, seating the assembly type beam-making pedestal foundation on the top surface of the constructed roadbed, and finally performing precast box beam operation through the assembly type beam-making pedestal foundation; the assembled beam manufacturing pedestal foundation comprises a plurality of sections of beam manufacturing pedestal monomers which are connected in sequence, the connecting ends of two adjacent sections of beam manufacturing pedestal monomers are spliced and connected by adopting a mortise and tenon structure, and long rod bolts are adopted at the connecting parts of the mortise and tenon structure for fixed connection.

2. The construction method of the fabricated girder fabrication pedestal for prefabricating a box girder of a high speed railway according to claim 1, wherein: the beam-making pedestal monomer is of a strip-shaped concrete structure which is integrally cast and formed, and consists of a wide strip body at the lower part and a narrow strip body at the upper part, and the vertical section of the beam-making pedestal monomer is in a convex shape; the beam-making pedestal single bodies are divided into two types of appearance styles, one type of beam-making pedestal single body is that the upper narrow strip bodies at the two ends of the beam-making pedestal single body are provided with bulges in an extending way, and the other type of beam-making pedestal single body is that the lower wide strip bodies at the two ends of the beam-making pedestal single body are provided with bulges in an extending way; the beam-making pedestal monomers of two appearance styles are sequentially and alternately and adjacently connected, and the convex narrow strip bodies and the convex wide strip bodies are mutually overlapped to form a mortise and tenon structure and are fixedly connected through long rod bolts.

3. The construction method of the fabricated girder fabrication pedestal for prefabricating the box girder of the high speed railway according to claim 2, wherein: the protruding narrow strip body and the protruding wide strip body are provided with embedded pipes for the insertion of the long rod bolts, and after the protruding narrow strip body and the protruding wide strip body are mutually overlapped, the embedded pipes on the protruding narrow strip body and the protruding wide strip body are in butt joint communication, the long rod bolts are inserted in the butted embedded pipes and are fixedly connected with the embedded pipes.

4. The construction method of the fabricated girder fabrication pedestal for prefabricating the high speed railway box girder according to claim 3, wherein the fabrication method of the girder fabrication pedestal monomer comprises the following steps: 1) assembling a module: firstly, polishing and cleaning the templates, then assembling the templates, controlling the size error of the assembled templates to be within 1cm, checking by adopting a mode of measuring the length, the width and the diagonal angle, and painting a release agent after the templates are assembled; 2) binding steel bars: the binding of the steel bars ensures the blanking size of the semi-finished steel bars, the control deviation is within 2cm, the binding position deviation is controlled after the steel bars are bound, and the control deviation is less than 1 cm; 3) installing an embedded part: the mounting requirement error of the anchor bolt preformed hole sleeve is within 1cm, and the pre-buried allowable error of the hanging nail hanger is 2 cm; 4) pouring concrete: checking the size of the template before concrete pouring, wherein the template is required to be tightly closed, if the gap of the template is too large, the template is adjusted, and if the gap is a structural gap, the template is blocked by using foam rubber to prevent slurry leakage in the concrete pouring process; vibrating according to the requirements strictly in the pouring process, achieving fast insertion and slow pulling, uniformly distributing vibration points, wherein the vibration time is 20-30 s each time, and the concrete is mainly treated when the concrete does not sink obviously any more, no air bubbles appear and the concrete begins to spread; 5) maintaining the prefabricated part: after the concrete is poured, covering geotextile or plastic film, watering and curing to keep the concrete surface wet; 6) demolding: the strength of the concrete is detected based on the notification of a laboratory, and the form is prevented from colliding with the concrete to cause unfilled edges and corner drop when the form is removed; 7) and (4) finished product inspection: and (3) detecting the length size of the prefabricated part by using a measuring tape, and detecting the flatness of the prefabricated part by using a level gauge and a feeler gauge.

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