CN115142354A - A kind of pre-embedded inner formwork and post-casting construction technology of tie beam for double-pier bridge pouring construction - Google Patents

Abstract

The invention relates to a pre-embedded inner formwork and post-casting construction technology for tie beams in the pouring construction of a double-pier bridge, which effectively solves the problems of poor post-casting combination of tie-beams, long construction period and high construction cost for synchronous casting; When the pier is poured, it is pre-buried in the concrete of the pier to form an umbrella-shaped cavity. When the inner form is pre-embedded, the connecting steel bars are pre-buried together. When the beam is tied after pouring, the tie beam mould cavity is connected with the cavity formed by the inner form. , at the end of the tie beam, an umbrella-shaped anchoring structure anchored in the pier column is formed; while the construction technology of post-casting the tie beam is realized, the long-term stability of the connection between the tie beam and the pier column is ensured, and the new and old concrete is compensated. Poor binding defect.

Description

A kind of pre-embedded inner formwork and post-casting construction technology of tie beam for double-pier bridge pouring construction

technical field

The invention relates to the field of bridge construction, in particular to a pre-embedded inner formwork and post-casting construction technology of a tie beam in the pouring construction of a double-pier bridge.

Background technique

Double-pier bridge is also called double-column pier, which means that two piers are set along the width direction of the bridge at the same longitudinal support position of the bridge, which are mostly used for ultra-wide bridges and ultra-high bridges. Or multiple horizontal tie beams connect two piers and columns to limit the position of the piers and columns, so that the two piers form a whole and improve the stability; the pouring construction of piers and columns with tie beams is divided into two types:

First, the tie beams are poured after the pier and column are poured. The disadvantage of this method is that the old and new concrete of the tie beam and the pier column are poorly combined; for the reverse method pier construction, because the pier is first punched and poured, the earthwork is excavated. method, the tie beam cannot be cast in situ, only this post-cast construction method can be used, and the tie beam is poured after the earthwork is excavated to the position of the tie beam, such as the invention patent of application number: CN201911185322.7; due to the stability of the combination of new and old concrete It is always a difficult technical problem to solve, and concrete has the characteristics of compressive but not tensile, so this post-casting method, the new and old concrete joint surface between the end face of the tie beam and the side wall of the pier column can withstand the tie beam for a long time. Under the condition of tension and compression alternating stress, there is a risk of cracking. Once the concrete cracks, the limiting effect of the tie beam will be greatly weakened or even lost;

The second is the simultaneous pouring method of tied beams and piers. When the piers and columns are poured to the height of the tied beams, a tied beam mold cavity that communicates with the pier-column mold cavity is built, and then the concrete is poured to complete the simultaneous pouring of the tied beams and the pier columns. For example, the application number: CN201911002742. 7 invention patent, in this way, the tie beam and the pier column are cast as a whole, and the tensile performance of the tie beam is stable. However, this method also has corresponding disadvantages: the pouring construction methods of longitudinal structures include climbing formwork construction, sliding formwork construction, and turning formwork construction. Due to the small amount of formwork used in climbing formwork construction and sliding formwork, the pouring process There is no need to remove the formwork, so it has the advantages of fast construction progress, low construction cost and less equipment investment, but it can only be used for the pouring of the upper and lower cross-section members. When the piers with tie beams are synchronously poured, they cannot be used due to the obstruction of the tie beams. Sliding form construction and climbing formwork construction can only be constructed by turning the formwork, and the turning formwork construction needs to repeatedly remove the lower formwork and connect it to the upper formwork, so the construction progress is slow, the construction period is long, the amount of formwork is large, and the position of the tie beam requires special formwork, construction high cost.

SUMMARY OF THE INVENTION

In view of the above situation, in order to solve the problems of poor tie-beam post-pouring combination, long construction period and high construction cost for simultaneous pouring, the present invention provides a pre-embedded inner formwork and tie-beam post-pouring construction technology for double-pier bridge pouring construction.

A pre-embedded inner mold for double-pier bridge pouring construction includes a main cylinder and a plurality of side cylinders, the inner end of the main cylinder is closed and the outer end is open, the two ends of the side cylinders are closed, and the inner end surface of the main cylinder is provided with a plurality of through holes, and the inner end of the main cylinder is closed. The circumference of each side cylinder is evenly distributed outside the main cylinder and forms a fixed angle with the axis of the main cylinder. The barrel forms an umbrella-like structure.

The inner end of the side cylinder and the main cylinder are fixed by bolts.

The outer ends of each of the side cylinders are provided with threaded holes.

A radial transverse brace is fixed in the main cylinder.

A post-casting construction technique for tie beams of a pre-embedded inner formwork for the pouring construction of a double-pier bridge, comprising the following construction steps:

Step 1: The pier column is poured, the pier column reinforcement cage is hoisted to the calibration position, the pier column formwork system is set up, and the pier column concrete is poured section by section from bottom to top;

Step 2: Pre-embed the inner mold, when the pier column is poured to a section below the bottom elevation of the tie beam, fix the side cylinder on the outer wall of the main cylinder with bolts, so that the main cylinder and the side cylinder form an umbrella-shaped inner mold, and then install the rib-shaped inner mold in the tie beam. The connection position between the beam end and the pier column is pre-embedded with an inner mold, and a pre-embedded connecting steel bar is inserted into each through hole of the main cylinder and is bound and fixed with the pier column reinforcement cage;

Step 3: Add pre-embedded connecting steel bars, and add embedded connecting steel bars on the periphery of the main cylinder within the projection range of the end face of the tie beam;

Step 4: Continue to pour the concrete of the pier column to the elevation;

Step 5: Pull out the inner mold, build the tie beam formwork, hoist the tie beam reinforcement cage, and connect the end of the tie beam steel bar with the embedded connecting steel bar;

Step 6: Pour the tie beam concrete to the top elevation of the tie beam;

Step 7: After the concrete is solidified, remove the tie beam formwork and complete the post-pouring operation of the tie beam.

In step 2, before tying the pre-embedded connecting bars, bind the horizontal transverse bars perpendicular to the pre-embedded connecting bars on the pier column reinforcement cages. superior.

In step 2 and step 3, the connection between the pre-embedded connecting steel bar and the through hole is sealed with foam rubber, the outer end of the main cylinder is sealed with bamboo plywood or foam board, the threaded hole at the outer end of the side cylinder and all the threaded sleeves are sealed. External ports are plugged with plastic films or rubber plugs.

In step 2, the inner threaded pipe is pre-embedded at a position lower than the bottom elevation of the tie beam, and the inner threaded pipe is arranged along the radial direction of the pier column. Tie beam formwork system.

In step 5, a miniature steel cage skeleton is implanted in the cavity formed by each side cylinder, the inner end of the skeleton is bound and fixed with the pre-embedded connecting steel bars in the cavity of the main cylinder, and the outer end of the skeleton is bound and fixed with the tie beam steel bars.

In step 5, after the inner mold is pulled out, the inner wall of the cavity of the inner mold is roughened, then the hole is cleaned, and the outer wall of the pier column at the joint position with the end of the tie beam is chiseled.

The invention adopts the construction technology of post-casting of the tie beam, and at the same time, through the rib-shaped anchoring structure at the end of the tie beam, the long-term stability of the connection between the tie beam and the pier column is ensured, and the defect of poor combination of new and old concrete is made up.

Description of drawings

FIG. 1 is a front sectional view of the inner mold.

Figure 2 is a right side view of the inner mold.

FIG. 3 is a front sectional view when the inner mold is pre-embedded.

FIG. 4 is an enlarged view of the position A in FIG. 3 .

Fig. 5 is a front cross-sectional view of the position of the cavity after the inner mold is demolded.

FIG. 6 is a front cross-sectional view of the tie beam steel formwork and the tie beam reinforcement cage after they are in place.

FIG. 7 is an enlarged view of the position B in FIG. 6 .

Figure 8 is a front cross-sectional view after the tie beam is poured.

In the above figures, 1-main cylinder, 2-side cylinder, 3-through hole, 4-bolt, 5-threaded hole, 6-cross brace, 7-pier column reinforcement cage, 8-pier column template, 9-pier Column concrete, 10-embedded connecting steel bar, 11-thread sleeve, 12-tie beam formwork, 13-tie beam reinforcement cage, 14-horizontal transverse bar, 15-internal threaded pipe, 16-corbel, 17-support beam , 18-miniature steel cage frame, 19-tie beam concrete.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

The inner mold includes a main cylinder 1 and a plurality of side cylinders 2. The inner end of the main cylinder 1 is closed and the outer end is open, and the two ends of the side cylinder 2 are closed. Installed on the pier column reinforcement cage 7, the opening of the main cylinder 1 faces outward, and a plurality of through holes 3 are opened on the inner end surface of the main cylinder 1, and the embedded connecting steel bars 10 are inserted into the through holes 3, and the inner end of the embedded connecting steel bars 10 is inserted. It is bound and fixed with the pier column reinforcement cage 7, and the outer end penetrates into the main cylinder 1 and is connected with the tie beam reinforcement when the tie beam is to be poured; a plurality of side cylinders 2 are evenly distributed around the main cylinder 1 and form a fixed clip with the axis of the main cylinder 1 Angle, the inner end of the side tube 2 is attached to the side wall of the main tube 1, and the outer end is flush with the outer end of the main tube 1. After the pier column formwork 8 at the tie beam position is in place, the inner wall of the formwork is in line with the main tube 1 and other parts. The outer ends of each side cylinder 2 are fitted together, and a plurality of main cylinders 1 and side cylinders 2 form an umbrella-shaped structure. After concrete is poured, the main cylinder 1 and the side cylinders 2 form an umbrella-shaped cavity.

The inner end of the side cylinder 2 and the main cylinder 1 are fixed by bolts 4. After the inner end of the side cylinder 2 is attached to the main cylinder 1, the bolts 4 are screwed from the inside of the main cylinder 1 to fix the side cylinder 2 and the main cylinder 1. It is ensured that the side drum 2 will not be displaced when the concrete is poured.

The outer end of each of the side cylinders 2 is provided with a threaded hole 5. When removing the formwork, a bolt 4 pull ring is screwed into the threaded hole 5, so that the side cylinder 2 can be easily pulled out of the concrete to complete the formwork removal.

The main cylinder 1 is fixed with a radial transverse brace 6, and the pre-embedded connecting steel bars 10 are bound and fixed with the transverse brace 6, so that the position of the main cylinder 1 is completely fixed so that it will not be displaced. The main cylinder 1 can also be easily pulled out from the concrete through the cross brace 6 during moulding.

The method of using the above-mentioned internal mold for pier column pouring and post-pouring construction of tied beams is as follows:

Step 1: The pier column is poured, the pier column reinforcement cage 7 is hoisted to the calibration position, the position and verticality of the center line axis are strictly controlled, and the pier column formwork 8 system is erected at the bottom of the pier column. The formwork can be constructed. After the formwork is brushed with release agent and placed in place, its position, elevation and horizontal stability shall be checked. After passing the test, the pier column concrete 9 shall be poured section by section from bottom to top, and the height of the pier column shall not exceed two meters at a time. When pouring, use a plug-in vibrator to vibrate and compact. Vibration is strictly prohibited to insert on the steel bar for vibration, and keep a distance of 5 to 10 cm from the formwork. The sign of vibration compaction is that the concrete will no longer collapse and there are no bubbles. Emergence, the surface is flat and slurred;

Step 2: Pre-embed the inner mold, when the pier column is poured to a section below the bottom elevation of the tie beam, fix the side tube 2 on the outer wall of the main tube 1 with bolts 4, so that the main tube 1 and the side tube 2 form an umbrella-shaped inner wall. and then pre-embed the inner mold at the connection position between the end of the tie beam and the pier column; specifically, after the inner mold is assembled, insert a pre-embedded connecting steel bar 10 into each through hole 3 at the bottom of the main cylinder 1, The threaded sleeve 11 is installed at the outer end of the embedded connecting steel bar 10 for subsequent connection with the tie beam steel bar, and then the main barrel 1 is hoisted to the calibration position, the barrel mouth is facing outward, and the barrel mouth is flush with the inner wall of the pier column formwork 8. The inner wall of the pier formwork 8 is fitted, and the outer ends of the main cylinder 1 and the side cylinder 2 are in the shape of intersecting lines that intersect with the inner wall of the pier formwork 8; Do not protrude out of the main barrel 1, and then bind and fix the inner end of the embedded connecting steel bar 10 to the pier column steel cage 7, and then bind and fix the embedded connecting steel bar 10 that is close to the cross brace 6 with the cross brace 6;

Step 3: Add pre-embedded connecting bars 10, and add pre-embedded connecting bars 10 on the periphery of the main tube 1 within the projection range of the end face of the tie beam; Install the threaded sleeve 11, and the outer end of the threaded sleeve 11 is flush with the inner wall of the pier formwork 8 for subsequent connection with the tie beam reinforcement;

Step 4: Continue to pour the concrete 9 of the pier column to the elevation; after the inner mold is fixed in place, apply a release agent to the outer wall of the inner mold, and then continue to pour the concrete 9 of the pier column to the elevation position of the top of the pier column, and remove the formwork to complete the pier column after solidification. the pouring work;

Step 5: Pull out the inner mold, build the tie beam formwork 12, hoist the tie beam reinforcement cage 13, and connect the end of the tie beam steel bar with the embedded connecting steel bar 10; before pouring the tie beam, first pull out the inner mold, the specific method To remove the bolt 4 from the main cylinder 1, remove the connection between the main cylinder 1 and the side cylinder 2, then remove the binding between the embedded connecting steel bar 10 and the cross brace 6, pull out the main cylinder 1 through the cross brace 6, Screw the pull ring on the threaded hole 5 at the outer end of the cylinder 2 to pull out the side cylinders 2 one by one; after the inner mold is removed, build the tie beam template 12 at the calibration position and hoist the reinforcement cage of the tie beam in place, and the template is painted and demoulded. Check the position, elevation and stability of the formwork, and the two ends of the tie beam steel bars are respectively connected with the threaded sleeves 11 at the ends of the embedded connecting steel bars 10 in the piers at both ends;

Step 6: Pour the tie beam concrete 19 to the top elevation of the tie beam; vibrate with the vibrating rod when inserting during pouring, pay attention to insert the vibrating rod into the reserved cavity at position 1 of the main cylinder to vibrate to ensure that the inner mold is reserved The concrete in the cavity is also vibrated and compacted;

Step 7: After the concrete is solidified, the tie beam formwork 12 is removed to complete the post-pouring operation of the tie beam.

In step 2, before tying the pre-embedded connecting bars 10, tie the horizontal transverse bars 14 perpendicular to the pre-embedded connecting bars 10 on the pier column reinforcing bars 7, and the inner ends of the pre-embedded connecting bars 10 can be bound on the reinforcing bars, and also It can be bound on the horizontal transverse bars 14 to avoid the distance between the pre-embedded connecting bars 10 and the main bars of the pier column bar cage 7 being too far to bind.

In step 2 and step 3, the connection between the pre-embedded connecting steel bar 10 and the through hole 3 is blocked with foam rubber, the outer end of the main cylinder 1 is blocked with bamboo glue board or foam board, the threaded hole 5 and the outer end of the side cylinder 2 are blocked with The outer ports of all threaded sleeves 11 are plugged with plastic films or rubber plugs to prevent concrete from entering the inner mold cavity.

In step 2, the inner threaded pipe 15 is pre-embedded at a position lower than the bottom elevation of the tie beam, and the inner threaded pipe 15 is arranged along the radial direction of the pier column. The legs 16 are used to carry the system of the tie beam formwork 12; the inner end of the inner threaded pipe 15 is fixed and closed by welding with the pier column reinforcement cage 7, and the outer end is 3 to 5 cm away from the inner wall of the pier column formwork 8. The outer port of the internally threaded pipe 15 is plugged, and the outer end of the rod is flush with the inner wall of the pier formwork 8, so that the internally threaded pipe 15 is completely embedded in the pier. The cylindrical plug at the outer end of the pipe 15 is screwed to the inner threaded pipe 15 with a screw, and then the corbel 16 is fixed on the screw with a nut, and then the support beam 17 is fixed on the corbel 16, and the support beam 17 is erected. tie beam formwork 12; after removing the tie beam formwork 12 in step 7, remove the corbel 16, and press the inner threaded pipe 15 with concrete slurry to seal it. The threaded pipe 15 is completely buried in the pier column, and will not leak and corrode outside, ensuring the integrity of the outer facade of the pier column.

In step 5, a miniature steel cage skeleton 18 is implanted in the cavity formed by each side cylinder 2, the inner end of the skeleton is bound and fixed with the pre-embedded connecting steel bar 10 in the cavity of the main cylinder 1, and the outer end of the skeleton is connected with the tie beam steel bar. Tie and fasten.

In step 5, after the inner mold is pulled out, the inner wall of the cavity of the inner mold is roughened, and then the hole is cleaned, and the outer wall of the pier column at the joint position with the end of the tie beam is chiseled to improve the bonding firmness of the old and new concrete.

The present invention adopts the construction technology of tie-beam post-casting, which is suitable for the reverse method bridge construction, and also enables climbing form casting and sliding form casting to be used for the pier and column casting operation of the double pier bridge with tie beam in the normal construction process, which can greatly improve the casting efficiency. The investment of equipment and personnel in the pouring construction is reduced; moreover, the inner mold device and the pre-embedding method of the present invention are simple and hardly increase the equipment cost and construction cost.

In the present invention, the rib-shaped inner mold is pre-buried, and the rib-shaped cavity is reserved in the pier column corresponding to the end of the tie beam. After the tie beam concrete 19 is poured, a stable formation is formed between the end of the tie beam and the pier column. The rib-shaped anchoring structure is designed to bear the main tension of the tie beam, and the concrete bonding force between the end face of the tie beam and the surface of the pier column is the auxiliary bearing force, which avoids the weakening or even the function of the post-cast tie beam due to the cracking of the new and old concrete joint surfaces. loss, ensuring the long-term stability of the post-cast tie beam.

Claims (10)

1. An embedded inner mold for double-pier bridge pouring construction, characterized in that it comprises a main cylinder (1) and a plurality of side cylinders (2), the inner end of the main cylinder (1) is closed and the outer end is open, and the side cylinders (2) ) are closed at both ends, a plurality of through holes (3) are opened on the inner end surface of the main cylinder (1), and the circumferences of a plurality of side cylinders (2) are evenly distributed outside the main cylinder (1) and are fixed to the axis of the main cylinder (1). Included angle, the inner end of the side cylinder (2) is in contact with the side wall of the main cylinder (1), and the outer end is flush with the outer end of the main cylinder (1), consisting of a plurality of main cylinders (1) and side cylinders (2). An umbrella-like structure. 2 . The pre-embedded inner mold for pouring construction of a double-pier bridge according to claim 1 , wherein the inner end of the side cylinder ( 2 ) and the main cylinder ( 1 ) are fixed by bolts ( 4 ). 3 . 3 . The pre-embedded inner formwork for double pier bridge pouring construction according to claim 1 , wherein the outer end of each of the side cylinders ( 2 ) is provided with a threaded hole ( 5 ). 4 . 4 . The pre-embedded inner formwork for double pier bridge pouring construction according to claim 1 , wherein a radial transverse brace ( 6 ) is fixed in the main cylinder ( 1 ). 5 . 5. A post-casting construction technique for tie-beams of a pre-embedded inner mold for double-pier bridge pouring construction, characterized in that the inner mold is any one of claims 1-(4), comprising the following construction steps: Step 1: The pier column is poured, the pier column reinforcement cage (7) is hoisted to the calibration position, the pier column formwork (8) system is set up, and the pier column concrete (9) is poured section by section from bottom to top; Step 2: When the inner mold is embedded, and the pier column is poured to a section below the bottom elevation of the tie beam, the side cylinder (2) is fixed on the outer wall of the main cylinder (1) with bolts (4), so that the main cylinder (1) and the The side barrel (2) forms an umbrella-shaped inner mold, and then the inner mold is embedded at the connection position between the end of the tie beam and the pier column, and an embedded connection is inserted into each through hole (3) of the main barrel (1). Reinforcing bars (10) are bound and fixed with the pier column reinforcement cages (7); Step 3: adding pre-embedded connecting steel bars (10), and adding pre-embedded connecting steel bars (10) located on the periphery of the main tube (1) within the projection range of the end face of the tie beam; Step 4: Continue to pour concrete (9) for the pier column to the elevation; Step 5: Pull out the inner mold, build the tie beam formwork (12), hoist the tie beam reinforcement cage (13), and connect the end of the tie beam steel bar with the embedded connecting steel bar (10); Step 6: Pour the tie beam concrete (19) to the top elevation of the tie beam; Step 7: After the concrete is solidified, the tie beam formwork (12) is removed to complete the post-pouring operation of the tie beam. 6 . The post-casting construction technique for the tie beam of the pre-embedded inner formwork for the double-pier bridge pouring construction according to claim 5, characterized in that, in step 2, before tying the pre-embedded connecting steel bars (10), the pier The column reinforcement cage (7) is bound with horizontal transverse bars (14) that are perpendicular to the embedded connection reinforcement bars (10). superior. 7 . The post-casting construction technique for tie-beams of a pre-embedded inner formwork for double-pier bridge pouring construction according to claim 5, characterized in that, in step 2 and step 3, pre-embedded connecting steel bars (10) and through holes (3) Block with foam rubber, block the outer end of the main cylinder (1) with bamboo plywood or foam board, and seal the threaded hole (5) at the outer end of the side cylinder (2) and all threaded sleeves (11). External ports are plugged with plastic films or rubber plugs. 8. The post-casting construction technique of the tie beam of the pre-embedded inner formwork of a double-pier bridge pouring construction according to claim 5, is characterized in that, in step 2, the inner thread is embedded at a position lower than the elevation of the bottom of the tie beam The pipe (15) and the inner threaded pipe (15) are arranged along the radial direction of the pier column. When the tie beam formwork (12) is built in step 5, the inner threaded pipe (15) is used to install the corbel (16) and is used to carry the tie beam Template (12) system. 9 . The post-casting construction process for the tie beam of the pre-embedded inner mold for the pouring construction of the double-pier bridge according to claim 5, characterized in that, in step 5, in the cavity formed by each side cylinder (2) A miniature steel cage frame (18) is implanted, the inner end of the frame is bound and fixed with the pre-embedded connecting steel bar (10) in the cavity of the main cylinder (1), and the outer end of the frame is bound and fixed with the tie beam steel bar. 10. The post-casting construction technique of the tie beam of the pre-embedded inner mold for a double-pier bridge pouring construction according to claim 5, is characterized in that, in step 5, after pulling out the inner mold, the inner wall of the inner mold cavity is carried out Pull the hair, then clear the hole, and chisel the outer wall of the pier column at the joint position with the end of the tie beam.

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