Formwork-free construction method with self-adaptive wet joint parameters of precast beam pieces

Abstract

The invention provides a prefabricated beam piece wet joint parameter self-adaptive formwork-erecting-free construction method which comprises the following steps that S1, components are prefabricated, specifically, beam pieces and joint plates are prefabricated, the joint plates are of table structures formed by symmetrical corner cutting of the top edges of the two sides of a square concrete prefabricated plate, inverted-U-shaped connecting steel bars are pre-embedded in the tops of the joint plates, and the inverted-U-shaped connecting steel bars are embedded in the top edges of the square concrete prefabricated plate; the bottom of the beam piece wing plate is provided with a slope surface with the same angle as the chamfers on the two sides of the joint plate, and wing plate steel bars are pre-embedded in the side face of the beam piece wing plate; s2, beam piece installation; s3, hoisting the joint plate; s4, the joint plate is suspended and supported; s5, mounting a steel bar net rack; and S6, joint pouring is conducted. According to the method, the problems that when a wet joint is constructed by temporarily erecting a bottom die in a traditional method, the adaptability to the width and height difference changes of the wet joint is poor, and the construction efficiency is low are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a formwork-free construction method with adaptive wet joint parameters of prefabricated beam pieces. Background Art

[0002] Highway, municipal road, and railway projects generally involve bridge construction. With the maturity of bridge construction technology, small and medium-span bridges are now mostly constructed using prefabrication. Beams are prefabricated at a prefabrication site, then transported to the site for installation using a bridge crane or crane. Pre-assembled beams are then welded or tied with pre-reinforced steel and poured with concrete to form a single, unconnected beam. Wet joints are crucial for transmitting force in prefabricated beam structures, but they are also vulnerable points during use. Current traditional wet joint construction methods present the following problems:

[0003] (1) The width of traditional wet joints is mostly 40cm to 80cm. Within this width range, steel bar binding or welding can meet the structural stress requirements and ensure structural safety. Due to the limitations of the prefabrication accuracy of the beam pieces and the flatness of the pier top, there may be a certain height difference between beam pieces installed in different positions. Based on the above, in actual construction, the width or height difference of the wet joints usually varies or changes. Therefore, the existing method of supporting the bottom formwork is difficult to flexibly adapt to the above parameter changes of the wet joints.

[0004] (2) At present, the common construction method for wet joints is suspension construction and various innovative methods based on suspension construction. It is necessary to install square timber or steel pipes, tension screws on the beams and support formwork at the bottom of the wet joints. After the construction is completed, the above components need to be removed. This will greatly reduce the speed of on-site construction and fail to meet the requirements of rapid bridge construction. At the same time, the formwork, square timber or steel pipes left on the bridge deck will lead to poor cleanliness of the bridge deck, which is not conducive to the finishing and roughening of the bridge deck concrete. The bolt holes formed by installing the tension screws are difficult to seal, which can easily cause water leakage on the bridge deck. When removing the formwork, the formwork at the bottom of the wet joint cannot be fixed. The bolts and nuts can only be unscrewed to let the formwork fall freely, which can easily damage the formwork and reduce the turnover of the formwork, thereby increasing construction costs. Summary of the Invention

[0005] In response to the above problems, the present invention provides a formwork-free construction method with adaptive parameters of wet joints of prefabricated beams, which solves the problems of poor adaptability to changes in the width and height difference of wet joints and low construction efficiency when constructing wet joints by temporarily setting up a bottom formwork in the traditional method.

[0006] The present invention is achieved through the following technical solutions.

[0007] A formwork-free construction method for prefabricated beam wet joint parameters with adaptive properties is characterized by comprising the following steps:

[0008] S1. Component prefabrication

[0009] The beams and joint plates are prefabricated. The joint plates are square concrete prefabricated plates with symmetrically cut corners on both sides of the top edge. Inverted U-shaped connecting steel bars are embedded in the top of the joint plates. The bottom of the beam flange has a slope with the same angle as the cut corners on both sides of the joint plates. Flange steel bars are embedded in the sides of the beam flange.

[0010] S2. Beam installation

[0011] Install the beam pieces on the piers;

[0012] S3. Seam plate hoisting

[0013] Use the lifting equipment to lift the joint plate to the bottom of the joint between adjacent beam pieces, and make the cut-angle surfaces on both sides of the joint plate fit with the slope surface at the bottom of the beam flange plate;

[0014] S4, joint plate suspension

[0015] Use support rods to cross the inside of the inverted U-shaped connecting steel bars, so that the two ends of the support rods overlap the flanges of the beams on both sides of the joint. Install jacks between the ends of the support rods and the flanges of the beams, and slowly lift the jacks synchronously so that the joint plate is suspended and supported in the joint between adjacent beams through the support rods and jacks, and the lifting equipment is relieved of the force to complete the force conversion;

[0016] S5. Steel mesh installation

[0017] Connect transverse connecting steel bars between the flange steel bars on both sides of the joint, and overlap the transverse connecting steel bars with the inverted U-shaped connecting steel bars at the transverse position, so that the flange steel bars, the inverted U-shaped connecting steel bars and the transverse connecting steel bars are connected to form an integral steel grid;

[0018] S6. Joint casting

[0019] Seal the joint between the cut corner surface of the joint plate and the slope surface of the beam wing plate, then pour the cast-in-place joint layer in the space enclosed by the joint plate and the beam wing plates on both sides, cover it with film and maintain it regularly. After the strength of the cast-in-place joint layer meets the requirements, remove the support rods and jacks.

[0020] Preferably, in step S1, the thickness of the corner cut portions on both sides of the joint plate accounts for 2 / 3 of the thickness of the entire plate.

[0021] Preferably, in step S1, the cutting angles on both sides of the seam plate are 40° to 60°.

[0022] Preferably, in step S1, the starting position of the slope of the bottom of the beam wing plate is at a position of 1 / 2 of the thickness of the beam wing plate.

[0023] Preferably, in step S1, the beam pieces and the joint plates are prefabricated at the same prefabrication site, the joint plates are prefabricated by simultaneously casting the remaining tailings from casting the beam pieces, and the top of the joint plates is roughened or brushed.

[0024] Preferably, in step S3, the joint plate is vertically lifted on one side of the joint along the length direction of the beam piece, and the joint plate is longitudinally translated to the bottom of the joint so that the joint plate passes laterally from the joint. Then, the lateral position of the joint plate is adjusted, and the joint plate is slowly lifted vertically so that the cut angle surfaces on both sides of the joint plate fit together with the slope surface at the bottom of the beam piece wing plate.

[0025] Preferably, in step S3, the lateral position of the joint plate is adjusted to control the horizontal distance Z between the vertical center line of the joint plate and the side surface of the beam wing plate on the higher side to be:

[0026] Z=(X- △ Y / tanβ) / 2

[0027] Where X is the seam width, Y is the seam height difference, and β is the cutting angle.

[0028] Preferably, in step S1, a plurality of connecting grooves are provided on the cut angle surfaces on both sides of the joint plate along the width direction of the joint plate, a steel mesh is installed in the connecting grooves, and a plurality of connecting holes corresponding to the connecting grooves are provided vertically through the beam wing plate, and steel bar heads are reserved on the inner wall surface of the connecting hole.

[0029] Preferably, step S5 also includes installing vertical connecting steel bars in the space where the connecting channel and the connecting groove are connected, so that one end of the vertical connecting steel bar is connected to the steel bar head and the other end is connected to the steel mesh; step S6 also includes pouring concrete in the space where the connecting channel and the connecting groove are connected.

[0030] Preferably, in step S3, a layer of asphalt with a thickness of less than 0.5 cm is first applied to the cut corner surfaces on both sides of the joint plate, and then the joint plate is hoisted.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) In this invention, by directly casting the joint plate with the concrete at the wet joint location to form an integral whole, this approach can reduce the problem of wet joint cracking caused by environmental disturbances. As long as the top surface layer is properly maintained and surface cracks are avoided, the wet joint can achieve good quality. In particular, this approach eliminates the need for bottom formwork, thereby avoiding many of the problems associated with bottom formwork construction.

[0033] 2) The present invention designs the joint plate into a platform structure with cut corners on both sides, and designs the bottom of the beam wing plate to have a slope with the same angle as the cut corners on both sides of the joint plate, so that the cut corner surface of the joint plate is in parallel contact with the slope of the bottom of the beam wing plate during installation. When the joint width or height difference changes, the position of the joint plate can be adjusted by moving to make the joint plate and the beam fit tightly. Therefore, the construction method of the present invention has good applicability to changes in wet joint parameters caused by insufficient beam installation accuracy or deviations in construction.

[0034] 3) In the method of the present invention, by lifting the joint plate from one side of the joint, the stability and safety of the initial installation of the joint plate can be ensured. At the same time, the joint plate completes the force conversion through the cooperation of the inverted U-shaped connecting steel bars, support rods and jacks, and the wing plate steel bars, inverted U-shaped connecting steel bars and transverse connecting steel bars are connected to form an integral steel grid, which can provide stable force support for subsequent joint casting, thereby ensuring construction safety.

[0035] 4) The present invention can improve the overall connection strength between the joint plate and the beams on both sides and enhance the bending resistance between the beams by arranging the connection grooves and the connection holes, and connecting the steel grid and pouring concrete in the space formed by the connection of the connection grooves and the connection holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the construction method of the present invention;

[0037] Figure 2 Schematic diagram of the construction of the steel mesh installation and joint plate suspension in the present invention;

[0038] Figure 3 Schematic diagram of the three-dimensional structure of the joint plate;

[0039] Figure 4 Schematic diagram of matching seams of different widths for seam panels;

[0040] Figure 5 Schematic diagram of matching different height difference joints for joint plates;

[0041] Figure 6 Design schematic diagrams for the dimensions of beams and joint plates;

[0042] Figure 7 This is a schematic diagram of position control during the hoisting of the joint plate;

[0043] Figure 8 This is a schematic diagram of the main structure of the bridge after construction according to the method of the present invention;

[0044] Figure 9 Schematic diagram of a preferred embodiment of the method of the present invention;

[0045] Figure 10for Figure 9 A magnified schematic diagram of point B in the middle;

[0046] Figure 11 for Figure 8 A magnified schematic diagram of point A in the middle;

[0047] The meanings of the symbols in the above figure are: beam piece 1, joint plate 2, inverted U-shaped connecting steel bar 3, flange steel bar 4, joint 5, support rod 6, jack 7, transverse connecting steel bar 8, lifting equipment 9, connecting channel 10, cast-in-place joint layer 11, connecting channel 12, steel bar head 13, vertical connecting steel bar 14, steel mesh 15, bridge pier 16, and bridge deck 17. DETAILED DESCRIPTION

[0048] The present invention will be further described below in the form of specific embodiments in conjunction with the accompanying drawings. It should be noted that the following embodiments are merely illustrative of the present invention in the form of examples, but the scope of protection of the present invention is not limited thereto. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0049] Example 1

[0050] This embodiment provides a prefabricated beam wet joint parameter adaptive formwork-free construction method, please refer to Figure 1 , which includes the following steps:

[0051] S1. Component prefabrication

[0052] Prefabricate the beam 1 and the joint plate 2; Figure 3 and Figure 6 The joint plate 2 is a platform structure formed by symmetrically cutting the top edges of both sides of the square concrete precast plate, and the top of the joint plate 2 is pre-embedded with an inverted U-shaped connecting steel bar 3; the bottom of the wing plate of the beam piece 1 has a slope with the same angle as the cutting angle of the two sides of the joint plate 2, and the side of the wing plate of the beam piece 1 is pre-embedded with a wing plate steel bar 4; in order to facilitate construction, the beam piece 1 and the joint plate 2 are prefabricated at the same prefabrication site, it is possible to consider planning a small component prefabrication site for prefabricated joint plates 2 at the prefabrication site of the beam piece 1, and the joint plate 2 is prefabricated synchronously with the remaining tailings of the beam piece 1. When pouring the joint plate 2, due to its thin structural design, the time and vibration intensity should be controlled during vibration. After pouring, its top should be chiseled or roughened to strengthen the connection between the subsequent cast-in-place joints or bridge deck pavement and the joint plate. After the prefabrication of the joint plate is completed, it can be transported by vehicles or machinery such as forklifts and cranes and stored together with the beam pieces.

[0053] In this embodiment, please refer to Figure 6 and Figure 7 , the prefabrication parameters of beam piece 1 and joint plate 2 are as follows: let the top width of joint plate 2 be a, the bottom width be b, the plate thickness be h, the bevel angle be β, the thickness of beam piece 1 flange be H, the width be L, the width of joint 5 be X, the height difference of joint 5, that is, the height difference of beam pieces on both sides of the joint be Y, and the unit of each dimension is cm; among them, the thickness of the beveled parts on both sides of joint plate 2 accounts for 2 / 3 of the total plate thickness, while the remaining bottom 1 / 3 maintains a square structure. This structural design can facilitate demoulding during construction on the one hand, and on the other hand, it can facilitate the protection of the finished product, so that the finished product will not be easily knocked and chipped by external forces during transportation and installation; the starting position of the slope of the bottom of beam piece 1 flange is at the position of 1 / 2 of the thickness of beam piece 1 flange to ensure the structural strength of the end of beam piece 1 flange; at this time, the parameters of joint plate 2 and beam piece 1 flange have the following relationship:

[0054]

[0055] See also Figure 4 and Figure 5 , since the angles of the cut corners on both sides of the joint plate 2 are the same as the slope angles of the bottom of the flange of the beam piece 1, the cut corners of the joint plate 2 are in parallel contact with the slope of the bottom of the flange of the beam piece 1 during installation. When the joint width X or the height difference Y changes, the position of the joint plate 2 can be adjusted by moving so that the joint plate 2 and the beam piece 1 fit tightly together. Through calculation, it can be seen that the range of the theoretical joint width X applicable to the joint plate 2 is (a-2L, b), but the minimum value a-2L and the maximum value b of this range are the critical positions of the contact between the joint plate 2 and the beam piece 1. In actual use, it is necessary to ensure that the horizontal contact width between the cut corners on both sides of the joint plate 2 and the slope of the bottom of the flange of the beam piece 1 is not less than 2 cm; then in fact, the range of the theoretical joint width X applicable to the joint plate 2 is (a-2L+4, b-4), that is, the minimum value of the suitable joint width is a-2L+4, and the maximum value is b-4; Substituting formula (1) and formula (2) into it, it can be seen that:

[0056] The range of the theoretical joint width X applicable to the joint plate (2) is:

[0057]

[0058] The range of variation of the theoretical joint width X applicable to the joint plate (2) is:

[0059]

[0060] Considering that the horizontal contact width between the angled surfaces on both sides of the joint plate 2 and the bottom slope of the flange of the beam 1 is not less than 2 cm, the range of the theoretical joint height difference Y applicable to the joint plate 2 can also be calculated as follows: Right now:

[0061]

[0062] The range of variation of the theoretical joint height difference Y applicable to joint plate 2 is:

[0063]

[0064] In order to reduce the weight of the prefabricated board and facilitate construction, the thickness h of the joint plate 2 should not be too large. In this embodiment, the thickness h of the joint plate 2 is 5 to 8 cm; and the thickness H of the flange of the beam piece 1 is determined according to the construction requirements. Therefore, in actual engineering, the thickness h of the joint plate 2 and the thickness H of the flange of the beam piece 1 are fixed values. Combining formula (3) and formula (4), it can be seen that the maximum theoretical joint width X of the joint plate 2 is max and minimum value X min It is related to the top width a of the joint plate 2 and the cutting angle β. Combining formula (5), it can be seen that the theoretical joint width variation range applicable to the joint plate 2 is △ X is only related to the cutting angle β, and is negatively correlated with the cutting angle β; combined with formula (6), it can be seen that the maximum theoretical joint height difference Y applicable to joint plate 2 is max It is related to the cutting angle β. Combined with formula (7), it can be seen that the theoretical joint height difference range applicable to the joint plate 2 is △ Y is only related to the cutting angle β and is positively correlated with the cutting angle β. The cutting angle β of the joint plate 2 will simultaneously affect the theoretical joint width and height difference range applicable to the joint plate 2, with the former being negatively correlated and the latter being positively correlated. Therefore, in order to take into account the joint width and height difference changes, the cutting angle β in this embodiment is set to 40° to 60°.

[0065] S2. Beam installation

[0066] The beam piece 1 is installed on the bridge pier 16 using conventional methods;

[0067] S3. Seam plate hoisting

[0068] Since the joint plate needs to be installed below the joint, but the joint plate is wider than the joint, the joint plate 2 is lifted vertically on one side of the joint 5 along the length direction of the beam 1 by using a lifting device, and the joint plate 2 is kept horizontal and 1-1.5m below the beam 1. Then the joint plate 2 is moved longitudinally to just below the joint 5, so that the joint plate 2 can pass safely and smoothly from the side of the joint 5. After that, the horizontal position of the joint plate 2 is adjusted, and the joint plate 2 is slowly lifted vertically so that the angled surfaces on both sides of the joint plate fit together with the slope surface at the bottom of the beam flange. At this time, it should be ensured that the beam flange is not subjected to force or only subjected to a small force from the joint plate to prevent the beam 1 from being disturbed by the joint plate and deviating from the installation position. At this time, the joint plate is only temporarily suspended below the joint by the lifting device to complete the initial positioning of the joint plate, but the joint plate is not firmly fixed.

[0069] Please refer to Figure 7 In this step, since the position of the beam piece is determined after installation and the joint width X and height difference Y are also determined, the joint plate 2 has only one installation position that makes the chamfered surface of the joint plate 2 parallel to the bottom slope of the flange of the beam piece 1. The horizontal position of the joint plate 2 can be determined by the horizontal distance Z between the vertical center line of the joint plate 2 and the side of the flange of the beam piece 1 on the higher side, and can be calculated using the following formula:

[0070]

[0071] Where X is the joint width, Y is the joint height difference, and β is the cutting angle;

[0072] In this step, a layer of asphalt with a thickness of less than 0.5 cm can be applied to the cut angle surfaces on both sides of the joint plate 2, and then the joint plate 2 can be lifted. First, it can cushion the impact or friction between the cut angle surfaces on both sides of the joint plate and the slope surface at the bottom of the beam wing plate when the joint plate is lifted or adjusted to a certain extent. Second, after the force conversion is completed in the subsequent step S4, the cut angle surfaces on both sides of the joint plate and the slope surface at the bottom of the beam wing plate can be closely fitted with each other and sealed to prevent leakage of slurry during joint pouring and water seepage on the bridge deck.

[0073] S4, joint plate suspension

[0074] See also Figure 2 The jack 7 is installed between the end of the support rod 6 and the wing plate of the beam piece 1 on both sides of the joint, and then the jack 7 is slowly lifted up synchronously, so that the joint plate 2 is suspended and supported in the joint 5 between the adjacent beam pieces 1 by the support rod 6 and the jack 7, and the lifting equipment is relieved of the force to complete the force conversion; at this time, the lifting rope can be removed and the relevant lifting equipment can be removed, and the joint plate will be stably fixed in the joint 5, and the angled surfaces on both sides of the joint plate and the slope surface at the bottom of the beam piece wing plate are closely fitted with each other; in this step, the support rod 6 is a steel pipe, and the jack 7 is a self-locking hydraulic jack; the inverted U-shaped connecting steel bar 3 should be reserved with a suitable length when it is embedded in step S1, so that after the joint plate 2 is initially fixed in step S3, there is space for the jack 7 and the support rod 6 to cooperate with each other;

[0075] S5. Steel mesh installation

[0076] See also Figure 2, connect the transverse connecting steel bars 8 between the wing plate steel bars 4 on both sides of the joint 5, and make the transverse connecting steel bars 8 overlap with the inverted U-shaped connecting steel bars 3 at the transverse position, so that the wing plate steel bars 4, the inverted U-shaped connecting steel bars 3 and the transverse connecting steel bars 8 are connected to form an integral steel grid; at this time, the joint plate 2 is connected to the beams on both sides through the steel grid to form an integral structure, and under the connecting and fixing action of the steel grid and the coordinated support and fixation of the jack 7 and the support rod 6, it can provide stable force support for the subsequent joint pouring;

[0077] S6. Joint casting

[0078] Use foam glue or polyurethane foaming agent and other foaming materials to seal the cutting edge of the joint plate 2 and the slope surface of the wing plate of the beam piece 1 to prevent leakage during pouring. Then use concrete of the same grade as the beam plate to cast the cast-in-place joint layer 11 in the space enclosed by the joint plate 2 and the wing plates of the beam piece 1 on both sides and cover it with a film and maintain it regularly. After the strength of the cast-in-place joint layer 11 meets the requirements, remove the support rod 6 and the jack 7; the inverted U-shaped connecting steel bars 3 exposed outside the cast-in-place joint layer 11 can be cut to a suitable length to overlap with the steel bars of the bridge deck surface layer, and then the subsequent paving construction of the bridge deck 17 can be carried out.

[0079] Example 2

[0080] See also Figures 8-11 This embodiment provides a formwork-free construction method for prefabricated beams with adaptive wet joint parameters, which is improved as follows based on the first embodiment:

[0081] Step S1 component prefabrication also includes: opening a plurality of connecting grooves 10 on the chamfered surfaces on both sides of the joint plate 2 along the width direction of the joint plate 2, and installing a steel mesh 15 in the connecting grooves 10. A plurality of connecting holes 12 corresponding to the connecting grooves 10 are vertically penetrated through the wing plate of the beam piece 1, and a steel bar head 13 is reserved on the inner wall surface of the connecting hole 12; specifically, the connecting groove 10 is arranged every 20-30 cm along the length direction of the joint plate 2, the width of the connecting groove 10 is 5-8 cm, the length of the connecting groove 10 is 2 / 3-4 / 5 of the length of the chamfered surface of the joint plate 2, and the depth of the connecting groove 10 is about 1 / 4 of the thickness of the joint plate 2; the diameter of the connecting hole 12 is slightly smaller than the width of the connecting groove 10;

[0082] Step S5 of the steel mesh installation further includes installing a vertical connecting steel bar 14 in the space connecting the connecting channel 12 and the connecting channel 10, so that one end of the vertical connecting steel bar 14 is connected to the steel bar head 13 and the other end is connected to the steel mesh 15;

[0083] Step S6 of the joint pouring also includes pouring concrete in the space where the connecting channel 12 and the connecting groove 10 communicate with each other.

[0084] Through the improvement of this embodiment, the overall connection strength between the joint plate and the beam pieces on both sides can be increased, and the bending resistance between the beam pieces can be enhanced.

Claims

1. A formwork-free construction method with adaptive wet joint parameters for prefabricated beams, characterized in that: The steps include: S1. Component prefabrication The beams and joint plates are prefabricated. The joint plates are square concrete prefabricated plates with symmetrically cut corners on both sides of the top edge to form a platform structure. The top of the joint plate is pre-embedded with inverted U-shaped connecting steel bars. The bottom of the beam flange has a slope with the same angle as the cut corners on both sides of the joint plate. The sides of the beam flange are pre-embedded with flange steel bars. S2. Beam installation Install the beam pieces on the piers; S3. Seam plate hoisting Use the lifting equipment to lift the joint plate to the bottom of the joint between adjacent beam pieces, and make the angled surfaces on both sides of the joint plate fit together with the slope surface at the bottom of the beam flange plate; S4, joint plate suspension Use support rods to cross the inside of the inverted U-shaped connecting steel bars, so that the two ends of the support rods overlap the flanges of the beams on both sides of the joint. Install jacks between the ends of the support rods and the flanges of the beams, and slowly lift the jacks synchronously so that the joint plate is suspended and supported in the joint between adjacent beams through the support rods and jacks, and the lifting equipment is relieved of the force to complete the force conversion; S5. Steel mesh installation Connect transverse connecting steel bars between the flange steel bars on both sides of the joint, and overlap the transverse connecting steel bars with the inverted U-shaped connecting steel bars at the transverse position, so that the flange steel bars, the inverted U-shaped connecting steel bars and the transverse connecting steel bars are connected to form an integral steel grid; S6. Joint casting Seal the joint between the cut corner surface of the joint plate and the slope surface of the beam wing plate, then pour the cast-in-place joint layer in the space enclosed by the joint plate and the beam wing plates on both sides, cover it with film and maintain it regularly. After the strength of the cast-in-place joint layer meets the requirements, remove the support rods and jacks.

2. The formwork-free construction method for precast beam wet joint parameters according to claim 1, characterized in that: In step S1, the thickness of the corner cut portions on both sides of the joint plate accounts for 2 / 3 of the thickness of the entire plate.

3. The formwork-free construction method for precast beam wet joint parameters according to claim 2, characterized in that: In step S1, the cutting angles on both sides of the joint plate are 40° to 60°.

4. The formwork-free construction method for precast beam wet joint parameters according to claim 3, characterized in that: In step S1 , the starting position of the slope of the bottom of the beam flange is at a position of 1 / 2 of the thickness of the beam flange.

5. The formwork-free construction method for precast beam wet joint parameters according to claim 1, characterized in that: In step S1, the beam pieces and the joint plates are prefabricated at the same prefabrication site. The joint plates are prefabricated by simultaneously casting the remaining tailings from casting the beam pieces, and the tops of the joint plates are roughened or brushed.

6. The formwork-free construction method for precast beam wet joint parameters according to claim 1, characterized in that: In step S3, the joint plate is vertically lifted on one side of the joint along the length direction of the beam, and the joint plate is longitudinally translated to the bottom of the joint so that the joint plate passes sideways from the joint. Then, the lateral position of the joint plate is adjusted, and the joint plate is slowly lifted vertically so that the cut angle surfaces on both sides of the joint plate fit together with the slope surface at the bottom of the beam flange.

7. The formwork-free construction method for precast beam wet joint parameters according to claim 6, characterized in that: In step S3, the lateral position of the joint plate is adjusted to control the horizontal distance Z between the vertical center line of the joint plate and the side surface of the higher beam flange to be: Z=(X- △ Y / andβ) / 2 Where X is the seam width, Y is the seam height difference, and β is the cutting angle.

8. The formwork-free construction method for precast beam wet joint parameters self-adaptation according to claim 1, characterized in that: In step S1, a number of connecting grooves are opened on the cut angle surfaces on both sides of the joint plate along the width direction of the joint plate, and a steel mesh is installed in the connecting grooves. A number of connecting holes corresponding to the connecting grooves are opened vertically through the beam wing plate, and steel bar heads are reserved on the inner wall surface of the connecting hole.

9. The formwork-free construction method for precast beam wet joint parameters self-adaptation according to claim 8, characterized in that: Step S5 further includes installing a vertical connecting steel bar in the space connecting the connecting channel and the connecting groove, so that one end of the vertical connecting steel bar is connected to the steel bar head and the other end is connected to the steel mesh; Step S6 also includes pouring concrete in the space where the connecting channel and the connecting groove communicate with each other.

10. The formwork-free construction method for precast beam wet joint parameters according to claim 9, characterized in that: In step S3, a layer of asphalt with a thickness of less than 0.5 cm is first applied to the cut corner surfaces on both sides of the joint plate, and then the joint plate is hoisted.

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