Prestressed concrete box girder short line matching segment precast system and construction method

Abstract

The application provides a prestressed concrete box girder short line matching segment prefabrication system and construction method, relates to the technical field of box girder short line matching segment prefabrication, and comprises the following steps: step 1, excavating a bottom mold pit; step 2, installing a side mold fixing base; step 3, installing and adjusting a bottom mold system; step 4, installing and adjusting a side mold; step 5, installing a steel reinforcement framework; step 6, installing and adjusting an inner mold and an end mold; and step 7, segment girder cyclic prefabrication. The application improves the occupying and adjusting mode of the bottom mold system, changes the side mold positioning and measuring mode, integrates the inner mold and the end mold system, reduces the operation space occupation, and improves the prefabrication operation precision and efficiency.

Description

Technical Field

[0001] This invention relates to the field of bridge prefabrication technology, and in particular to a prefabrication system and construction method for short-line matching segments of prestressed concrete box girders. Background Technology

[0002] With the continuous development of society and economy and the advancement of bridge construction technology, bridges are transforming towards higher quality, higher efficiency, energy conservation, and environmental protection. Compared to traditional methods such as scaffolding construction and cantilever symmetrical casting, segmental precast assembly technology offers advantages such as reduced investment, shorter construction time, less environmental impact and pollution, and no need to occupy the space beneath the bridge. Therefore, this technology has gained increasing popularity in prestressed concrete bridges, making its application and development more eye-catching and widely recognized in the construction industry worldwide.

[0003] Segmental bridge construction involves dividing the beam into segments, prefabricating the segments in a factory, moving them to the bridge site for assembly, and applying prestress to make the segmental beams an integral structure. The segmental beam construction method has the advantages of being technically reasonable and having controllable product quality, and it can realize the factory prefabrication of large-span bridges. This construction method has a high degree of industrialization, but this assembly construction method has certain limitations: (1) At present, short-line matching segmental beam components are generally produced using a fixed formwork process. The end face of the cast segment is the end form of the next segment, which requires precise matching to ensure the splicing accuracy of adjacent segments. The matching accuracy is high and the time required is long. (2) At present, the side formwork, bottom formwork, inner formwork, and end formwork of the matching beam are set separately. The formwork positioning process is complicated and the formwork is large, resulting in a low degree of automation, which limits the advantages of the short-line matching method segmental box girder construction technology. Summary of the Invention

[0004] The purpose of this invention is to provide a precast system and construction method for short-line matching segments of prestressed concrete box girders that solves the above-mentioned technical problems.

[0005] To address the aforementioned technical problems, this invention provides a precast system and construction method for short-line matching segments of prestressed concrete box girders, comprising the following steps:

[0006] Step 1: Excavate the bottom formwork pit: Divide the prefabrication area, and excavate a continuous pit of the same width as the bottom formwork in the area of ​​the prefabricated box girder. The center line of the pit's axis overlaps with the center line of the box girder's axis.

[0007] Step 2: Install side formwork fixing bases: Construct at least two full-length bases symmetrically on the ground on both sides of the pit, and install slide rails on the bases;

[0008] Step 3: Install and adjust the bottom formwork system: Install at least two tracks symmetrically on the bottom surface of the pit. Install the bottom formwork trolley base plate on the tracks. The bottom formwork trolley base plate can slide along the tracks under power. Then, install several sets of support points at intervals along the longitudinal and transverse directions on the bottom formwork trolley base plate. Install the corresponding chassis and telescopic cylinder on each set of support points. Install support beams on the top of several adjacent telescopic cylinders in the transverse direction to form several longitudinally spaced support beams. Install the bottom formwork on several longitudinally spaced support beams.

[0009] Step 4: Install and adjust the side formwork: Before adjusting the side formwork, move the completed matching section to the matching position using the bottom formwork system, and limit the completed matching section using the fixing frame. The fixing frame is fixed to the hardened ground by anchored concrete. The width of the side formwork is greater than the width of a single completed matching section. When the side formwork is in place, the side formwork and the side adjacent to the completed matching section fit together to cover the segment boundary line.

[0010] Step 5: Install the steel reinforcement cage;

[0011] Step 6: Install and adjust the inner mold and end mold: The inner mold and end mold share the same mobile trolley. The base of the mobile trolley has wheels. The wheels move on the hardened ground, which drives the inner mold system and end mold system supported on the mobile trolley to be in place or detached. The inner mold system and end mold system are relatively independent.

[0012] Step 7: Cyclic Precasting of Segmental Beams: Install formwork, pour concrete, and move the newly poured segment to the matching beam position as the matching beam for the next segment precasting, thus completing the short-line matching segment precasting of the box girder.

[0013] The beneficial effects of this invention are as follows:

[0014] (1) The present invention places the bottom formwork system in the bottom pit, saving ground operation space. The bottom formwork system can be flexibly positioned in planar position by sliding along the track. The bottom formwork can be linearly adjusted in elevation and slope by linkage extension and retraction of the telescopic cylinder. The lowered bottom formwork provides sufficient adjustment space for the telescopic cylinder, thereby realizing the prefabrication of segmental beams with variable cross-section.

[0015] (2) The present invention limits the position of the side formwork of the segment to be poured by linking the already matched segments, thereby helping to limit the side boundary range of the segment to be poured, improving the positioning accuracy of the formwork, and improving the linear matching between the segment to be poured and the already matched segments.

[0016] (3) By setting measuring points on the side mold, the position of the side mold is located in real time by the relative position of the measuring points and the base point. The position information of the side mold is displayed in real time by digital means, which satisfies the dynamic real-time judgment of the side mold adjustment process, improves the side mold adjustment accuracy and adjustment efficiency.

[0017] (4) The present invention integrates the inner mold and the end mold on the same mobile trolley, and the inner mold system and the end mold system are relatively independent, and their positions do not interfere with each other, thereby improving the integration level of the template trolley and reducing the space occupied in operation. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the prefabrication system of the present invention in operation.

[0019] Figure 2 This is a longitudinal cross-sectional view of the prefabrication system of the present invention in operation.

[0020] Figure 3 This is a top view of the inner mold and end mold system of the prefabrication system of the present invention in operation.

[0021] Figure 4 This is a schematic diagram of the end model.

[0022] The attached diagram lists the components represented by each number as follows:

[0023] 1-Segmental beam; 2-Ground; 3-Base; 4-Slide rail; 5-Side mold trolley; 6-Side mold; 7-First hydraulic rod; 8-Second hydraulic rod; 9-Third hydraulic rod; 10-First base point; 11-Second base point; 12-Third base point; 13-First measuring point; 14-Second measuring point; 15-Third measuring point; 16-Pit; 17-Pit bottom; 18-Railway; 19-Bottom mold trolley base plate; 20-Fulcrum; 21-Chassis; 22-Telescopic cylinder; 23-Support beam; 24-Bottom mold; 25-Connecting bolt; 26-Support frame; 27-Left corner inner mold; 2 8-Right corner inner mold; 29-Top inner mold; 30-Bottom inner mold; 31-Inner mold hydraulic rod; 32-Angle adjusting hydraulic rod; 33-Hardened ground; 34-Anchored concrete; 35-Fixing frame; 36-Completed matching section; 37-Base point; 38-Measuring point; 39-Segment boundary line; 40-Segment to be poured; 41-Mobile trolley; 42-Wheel; 43-Base; 44-Inner mold system; 45-Side frame; 46-Side connecting block; 47-Railway groove; 48-Pole frame; 49-Support rod; 50-Connecting rod; 51-End mold; 52-Fixing point; 53-Inner mold. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0026] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0027] Please see Figure 1-4 As shown, this embodiment provides a precast system and construction method for short-line matching segments of prestressed concrete box girders. For ease of description, the following explanation is provided: When the first segment of the beam is precast, there is no completed matching segment beam 1 as a fixed end mold 51. Therefore, two sets of end molds 51 are used for precasting. The remaining process methods are the same as those for precasting the remaining segment beams 1. The segment beam 1 cyclic precasting method described in this invention is a precasting method that uses the first segment beam as a fixed end mold 51 after the first segment beam has been precast. Therefore, this invention will not provide further description of the first segment beam precasting method. The precast system and construction method for short-line matching segments of prestressed concrete box girders include the following steps:

[0028] Step 1: Excavate the bottom formwork 24 pits and 16 trenches.

[0029] The prefabrication area is divided, and a continuous trench 16 of the same width as the bottom formwork 24 is excavated in the area of ​​the prefabricated box girder. The center line of the trench 16 overlaps with the center line of the box girder axis.

[0030] Step 2: Install the side mold 6 fixing seat.

[0031] At least two long bases 3 are symmetrically constructed on the ground 2 on both sides of the pit 16, and slide rails 4 are installed on the bases 3.

[0032] Step 3: Install and adjust the bottom mold 24 system.

[0033] Inside the pit 16, at least two tracks 18 are symmetrically installed on the bottom surface 17 of the pit. A bottom mold trolley base plate 19 is installed on the tracks 18. The bottom mold trolley base plate 19 can slide along the tracks 18 under power. Then, several sets of support points 20 are installed at intervals along the longitudinal and transverse directions on the bottom mold trolley base plate 19. A corresponding chassis 21 and telescopic cylinder 22 are installed on each set of support points 20. A support beam 23 is installed on the top of several adjacent telescopic cylinders 22 in the transverse direction to form several longitudinally spaced support beams 23. The bottom mold 24 is installed on several longitudinally spaced support beams 23.

[0034] The bottom plate 19 of the bottom mold trolley is provided with a rotatable roller on the side near the track 18, which allows the bottom plate 19 of the bottom mold trolley to slide along the track 18.

[0035] By sliding the bottom plate 19 of the bottom formwork trolley on the track 18, the bottom formwork 24 is supported and slids simultaneously, thus realizing the positioning of the bottom formwork 24 in the plane. By the linkage extension and retraction of the telescopic cylinder 22, the elevation of the bottom formwork 24 can be adjusted, and the slope and line of the bottom formwork 24 can be adjusted by adjusting the linear height of the telescopic cylinder 22, thereby realizing the prefabrication of the segmental beam 1 with variable cross section.

[0036] The adjustment of the linear height of the telescopic cylinder 22 refers to increasing the height of each row of telescopic cylinders arranged laterally by a certain amount compared to the previous row, thereby making each row of telescopic cylinders arranged at an inclined slope.

[0037] Step 4: Install and adjust the side mold 6.

[0038] Before adjusting the side formwork 6, the completed matching segment 36 is moved to the left to the matching position using the bottom formwork 24 system. The left end of the completed matching segment 36 is limited by the fixing frame 35, which is fixed to the hardened ground 33 by the anchoring concrete 34. The width of the side formwork 6 is greater than the width of a single completed matching segment 36. When the side formwork 6 is in place, the side formwork 6 and the adjacent side of the completed matching segment 36 fit together so that the side formwork 6 covers the segment boundary line 39. In this way, the right boundary of the completed matching segment 36 defines the position of the side formwork 6. That is, when positioning the side formwork 6 of the segment to be poured 40, the position of the side formwork 6 is first defined by the completed matching segment 36. Since the completed matching segment 36 and the segment to be poured 40 are adjacent linear matching segments, this helps to limit the side boundary range of the segment to be poured 40, improve the positioning accuracy of the formwork, and thus improve the linear matching between the segment to be poured 40 and the completed matching segment 36.

[0039] The side mold 6 system is implemented by: installing a side mold trolley 5 on the slide rail 4 of the base 3; installing a first hydraulic rod 7, a second hydraulic rod 8, and a third hydraulic rod 9 on the side mold trolley 5; all hydraulic rods are located on one side of the precast beam, supporting the side mold 6. The position of the side mold 6 is adjusted by changing the angle and length of the hydraulic rods.

[0040] Before the side formwork 6 is precisely positioned, the relative position information of the side formwork 6 to be positioned is first determined. The first measuring point 13, the second measuring point 14, and the third measuring point 15 are set on the outside of the side formwork 6. The first base point 10, the second base point 11, and the third base point 12 are set on the surface of the base 3 near the precast beam. The three sets of base points 37 are fixed measuring points, that is, the position coordinates of the three sets of base points 37 are fixed. The position coordinates of the side formwork 6 are represented by the relative position coordinates of the three sets of measuring points 38 relative to the three sets of base points 37. That is, the relative position information of the side formwork 6 to be positioned is first calculated before the side formwork 6 is precisely positioned.

[0041] In one embodiment of this solution, the positioning relationship between the three sets of base points 37 and the three sets of measuring points 38 can be such that when the three sets of base points 37 and the three sets of measuring points 38 are on the same vertical line, it means that the vertical position of the side mold 6 is accurate. At the same time, by measuring the distance between the three sets of measuring points and the three sets of base points, it is possible to know whether the tilt angle, positioning height, etc. at each position of the side mold are accurate, thereby increasing the accuracy of the relative position when the side mold 6 is to be positioned.

[0042] An infrared ray emitting device is installed on each measuring point 38. The infrared rays are emitted to locate and measure the corresponding base point 37. Since the position coordinates of the three sets of base points 37 are fixed, the coordinate information of the measuring point 38 relative to the base point 37 can be measured. The relative coordinate information is generated and uploaded to the computer while adjusting the hydraulic rod. The position coordinates of the side mold 6 can be determined in real time. The real-time position coordinates of the side mold 6 are compared with the initial relative position information of the side mold 6 to determine whether the side mold 6 is in place according to the planned coordinates. By adjusting the hydraulic rod while judging the relative position information of the side mold 6, the side mold 6 is finally accurately positioned.

[0043] The side mold and the bottom mold are temporarily fixed together by connecting screws 25.

[0044] Step 5: Install the steel reinforcement cage.

[0045] Step 6: Install and adjust the inner mold 53 and the end mold 51.

[0046] The inner mold 53 and the end mold 51 share the same mobile trolley 41. The base 43 of the mobile trolley 41 has wheels 42. The wheels 42 move on the hardened ground 33, which drives the inner mold system 44 and the end mold 51 system supported on the mobile trolley 41 to be in place or detached. The inner mold system 44 and the end mold 51 system are relatively independent.

[0047] The middle part of the mobile trolley 41 is equipped with a support frame 26, which is connected to the inner mold 53 via the inner mold hydraulic rod 31 and adjusts the angle of the inner mold 53.

[0048] The mobile trolley 41 has a side frame 45. A rail groove 47 is mounted on the outer side of the side frame 45 via a side connecting block 46. A sliding connecting rod 48 is installed within the rail groove 47. The end of the rod 48 has a support rod 49, which is connected to the end mold 51 via a connecting rod 50. The rail groove 47, rod 48, support rod 49, and connecting rod 50 are sequentially connected, and the connecting rod 50 is connected to a fixed point 52 on the end mold 51. The rail groove 47, rod 48, support rod 49, and connecting rod 50 are sequentially connected to form a set, and the end mold 51 is connected to at least four sets. The sliding of the rod 48 within the rail groove 47 causes the end mold 51 to be positioned or disengaged.

[0049] Based on this, the inner mold system 44 and the end mold system 51 are relatively independent, and their positions do not interfere with each other.

[0050] The inner mold 53 is composed of a left corner inner mold 27, a right corner inner mold 28, a top inner mold 29, and a bottom inner mold 30. The opening degree of the lower corner of the left corner inner mold 27 is adjusted by the angle-adjusting hydraulic rod 32.

[0051] Step 7: Cyclic prefabrication of segmental beam 1

[0052] The template is installed and concrete is poured using the above method. The newly poured segment is then moved to the matching beam position as the matching beam for the next segment to be prefabricated, thus completing the prefabrication of the short-line matching segment of the box girder.

[0053] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method for a precast system of short-line matched segments for prestressed concrete box girders, characterized in that, Includes the following steps: Step 1: Excavate the bottom formwork (24) pit (16): Divide the prefabrication area and excavate a continuous pit (16) of the same width as the bottom formwork (24) in the area of ​​the prefabricated box girder. The center line of the pit (16) overlaps with the center line of the box girder. Step 2: Install side formwork (6) fixing base: Construct at least two long bases (3) symmetrically on the ground (2) on both sides of the pit (16), and install slide rails (4) on the bases (3); Step 3: Install and adjust the bottom formwork (24) system: Install at least two tracks (18) symmetrically on the bottom surface (17) of the pit. Install the bottom formwork trolley base plate (19) on the tracks (18). The bottom formwork trolley base plate (19) can slide along the tracks (18) under the power drive. Then, install several sets of support points (20) at intervals in the longitudinal and transverse directions on the bottom formwork trolley base plate (19). Install the corresponding chassis (21) and telescopic cylinder (22) on each set of support points (20). Install support beams (23) on the top of several adjacent telescopic cylinders (22) in the transverse direction to form several longitudinally spaced support beams (23). Install the bottom formwork (24) on several longitudinally spaced support beams (23). Step 4: Install and adjust the side formwork (6): Before adjusting the side formwork (6), move the completed matching section (36) to the matching position through the bottom formwork (24) system, and limit the completed matching section (36) through the fixing frame (35). The fixing frame (35) is fixed to the hardened ground (33) by the anchoring concrete (34). The width of the side formwork (6) is greater than the width of a single completed matching section (36). When the side formwork (6) is in place, the side formwork (6) and the side adjacent to the completed matching section (36) fit together so that the side formwork (6) covers the segment boundary line (39). Step 5: Install the steel reinforcement cage; Step 6: Install and adjust the inner mold (53) and the end mold (51): The inner mold (53) and the end mold (51) share the same mobile trolley (41). The base (43) of the mobile trolley (41) has wheels (42). The wheels (42) move on the hardened ground (33), which drives the inner mold system (44) and the end mold (51) system supported on the mobile trolley (41) to be in place or detached. The inner mold system (44) and the end mold (51) system are relatively independent. Step 7, segmental beam (1) cyclic prefabrication: Install the formwork, pour concrete, move the newly poured segment to the matching beam position as the matching beam for the next segment prefabrication, and complete the short-line matching segment prefabrication of the box girder.

2. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 1, characterized in that: In step three, the bottom mold (24) is supported by the sliding of the bottom plate (19) of the bottom mold trolley on the track (18) and slides at the same time, so as to realize the positioning of the bottom mold (24) in the plane. The bottom mold (24) is adjusted in elevation by the linkage extension and retraction of the telescopic cylinder (22), and the slope line adjustment of the bottom mold (24) is realized by adjusting the linear height of the telescopic cylinder (22), so as to realize the variable cross section prefabrication of the segment beam (1).

3. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 1, characterized in that: In step four, the implementation of the side mold (6) system includes: installing a side mold trolley (5) on the slide rail (4) of the base (3), installing a first hydraulic rod (7), a second hydraulic rod (8), and a third hydraulic rod (9) on the side mold trolley (5). The hydraulic rods are all located on one side of the precast beam, and the side mold (6) is supported by the hydraulic rods. The position of the side mold (6) is adjusted by changing the angle and length of the hydraulic rods.

4. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 1, characterized in that: In step four, before the side formwork (6) is precisely positioned, the relative position information of the side formwork (6) is first determined. The first measuring point (13), the second measuring point (14), and the third measuring point (15) are set on the outside of the side formwork (6). The first base point (10), the second base point (11), and the third base point (12) are set on the surface of the base (3) near the precast beam. The three sets of base points (37) are used as fixed measurement points. The position coordinates of the side formwork (6) are represented by the relative position coordinates of the three sets of measuring points (38) relative to the three sets of base points (37).

5. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 4, characterized in that: An infrared ray emitting device is installed on each measuring point (38). The corresponding base point (37) is located by emitting infrared rays. The relative coordinate information is generated by adjusting the hydraulic rod and uploaded to the computer. The position coordinates of the side mold (6) are determined in real time. The real-time position coordinates of the side mold (6) are compared with the initial relative position information of the side mold (6) to determine whether the side mold (6) is in place according to the planned coordinates.

6. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 1, characterized in that: The middle part of the mobile trolley (41) is equipped with a support frame (26). The support frame (26) is connected to the inner mold (53) through the inner mold hydraulic rod (31) and the angle of the inner mold (53) is adjusted. The mobile trolley (41) is equipped with a side frame (45). The outer side of the side frame (45) is equipped with a rail groove (47) through a side connecting block (46). The rail groove (47) is connected to a sliding rod frame (48). The end of the rod frame (48) is equipped with a support rod (49). The support rod (49) is connected to the end mold (51) through a connecting rod (50). The rail groove (47), rod frame (48), support rod (49), and connecting rod (50) are connected in sequence. The connecting rod (50) is connected to a fixed point (52) on the end mold (51). The rail groove (47), rod frame (48), support rod (49), and connecting rod (50) are connected in sequence to form a group and the end mold (51) is connected to at least four groups.

7. The construction method of the prestressed concrete box girder short-line matching segment prefabrication system according to claim 1, characterized in that: The inner mold (53) is composed of a left corner inner mold (27), a right corner inner mold (28), a top inner mold (29), and a bottom inner mold (30). The opening degree of the lower corner of the left corner inner mold (27) is adjusted by the angle-adjusting hydraulic rod (32).

8. A precast system for short-segment matching prestressed concrete box girders, characterized in that: The prestressed concrete box girder short-line matching segment prefabrication system as described in any one of claims 1-7 is obtained through construction.

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