Curve steel box girder variable cross slope assembling incremental launching construction method

Abstract

The invention discloses a curved steel box girder variable cross slope assembly incremental launching construction method which comprises the following steps: dynamically adjusting a construction cross slope through spatial rotation: rotating a target linetype to reduce the cross slope by taking a line connecting line of line axis points of an original target steel girder as a rotating shaft during first assembly, solving post-rotation target data of the first assembly, and completing the assembly; the process is iterated in subsequent assembly, the beam is reset after construction is completed, the transverse component force on the beam body bearing face is reduced, the beam body instability risk under the large cross slope working condition is avoided, and therefore steel box beam assembly and incremental launching construction are safer, and the method is suitable for the field of bridge construction.

Description

Technical Field

[0001] The invention relates to the technical field of steel box girder assembly and jacking construction of bridges, and in particular to a method for assembling and jacking construction of curved steel box girders with variable transverse slopes. Background Art

[0002] The construction principle of the steel box girder jacking method is to set up an assembly platform behind the platform along the longitudinal axis of the bridge, assemble the beam sections according to the designed cross slope, apply horizontal force through the jack, and use the sliding device to push the beam forward section by section. After the beam is in place, it will be dropped and the formal support will be replaced.

[0003] In traditional steel box girder jacking construction, beam sections are assembled according to the designed transverse slope (e.g. 5%). During jacking, the lateral component of the beam bottom is too large, leading to the risk of beam instability. Existing technologies lack solutions for dynamically adjusting the transverse slope during construction, making it difficult to balance structural safety and design accuracy. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a curved steel box girder variable cross-slope assembly and jacking construction method, which reduces the cross slope of the beam bottom to a safe range during the assembly and jacking stage and resets it to the designed cross slope after completion.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A method for assembling and pushing a curved steel box girder with a variable transverse slope is characterized by comprising the following steps:

[0007] S1. Establish target alignment: According to the steel box girder design and construction drawings, establish the target plane and elevation alignment of the top surface of the steel box girder under each assembly condition. The target plane and elevation alignment include the beam axis and beam edge line.

[0008] S2. Calculate target values: Under each assembly condition, calculate the plane coordinates (x, y) and elevation (h) target values ​​of the top axis and edge points at the front and rear section sections of the steel box girder segment to be assembled;

[0009] S3. Assembly and adjustment on the first support: On the support in the steel beam assembly area, use the line connecting the axis point A of the first section and the axis point B of the tail section of the first assembly section as the spatial rotation axis to rotate the target linearly in space. The rotation direction is to reduce the cross slope of the beam bottom. The rotation amount is determined by the difference between the design cross slope and the safe cross slope. After the rotation, the on-site linear control data (x, y, h) of the AB segment of the first assembly working condition is generated, and on-site adjustment and assembly are carried out accordingly.

[0010] S4. Pushing construction: Assemble the steel box beams according to the adjusted line shape, and use the reaction jacks arranged on the supports and piers with the function of moving the steel box beams longitudinally and transversely to push the beam sections to the target mileage;

[0011] S5, subsequent assembly: During the subsequent assembly, the target line shape is spatially rotated again with the line connecting the axis point B of the head section and the axis point C of the tail section of the segment to be assembled as the rotation axis. The rotation direction is also in the direction of reducing the cross slope, and the rotation amount is the same as step S3. After the rotation, the on-site line shape control data of the assembled and to-be-assembled steel box girders of the BC segment under this working condition are obtained;

[0012] S6, fine-tuning and assembly: According to the linear control data of step S5, fine-tune the linear shape of the assembled steel box girder, assemble the segments to be assembled, and control the vertical angle, lateral angle and twist deviation between the segments;

[0013] S7, repeat construction: repeat steps S5 and S6 until all segments are assembled and pushed;

[0014] S8. Drop the beam and restore it to its original position: Install permanent supports, drop the steel box beam to the designed elevation, and restore the cross slope at the bottom of the beam to the designed state.

[0015] Furthermore, the spatial rotation of step S3 and step S5 is achieved by the following calculation; let the direction vector of the rotation axis L be u=( ), u is the direction vector, and the rotation axis passes through the point =( ), for any point P=(x,y,z), rotate around L by angle The coordinates are: Where R is the rotation matrix; is the rotation angle; is the coordinate of point P after rotation around the rotation axis L.

[0016] Furthermore, the calculation formula of the rotation matrix R is:

[0017] Furthermore, the rotation axis L is determined by the axis point A and the axis point B;

[0018] Take the coordinates of point B ( );

[0019] Direction vector .

[0020] Furthermore, the steps for rotating point P=(x, y, z) around the rotation axis L are as follows

[0021] a. Translation: translate point P to is the coordinate system with the origin;

[0022] b. Rotation: Apply the rotation matrix R to rotate ;

[0023] c. Inverse translation: the rotated point Translate back to the original coordinate system;

[0024] Furthermore, the design cross slope is 5%, the safety cross slope is 3%, the rotation amount corresponds to a 2% cross slope reduction value, and the rotation angle Design cross slope Assembling safety slopes The direction of the difference is the direction of the smaller slope, that is

[0025] Furthermore, in step S6, the geometric relationship between the assembled segment and the segment to be assembled is obtained by rotating the designed three-dimensional coordinates around the rotation axis by a certain amount.

[0026] Furthermore, in step S8, the horizontal slope of the bottom of the beam is reset by adjusting the height of the permanent support.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention adjusts the transverse slope of a steel box girder under construction when the designed transverse slope is relatively large, which can greatly reduce the safety risks of construction.

[0029] 2. By dynamically adjusting the cross slope of the bottom of the beam during construction from the design value of 5% to the safety value of 3%, the lateral component of the beam support surface is significantly reduced, avoiding beam instability.

[0030] 3. Use the spatial rotation matrix to adjust the line shape to ensure assembly accuracy and smooth beam lines.

[0031] 4. The above method has clear steps and is easy to implement on site, and is particularly suitable for the large cross slope construction of curved steel box girders. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings:

[0033] Figure 1 This is a structural schematic diagram of the first assembly of a curved steel box girder with a variable transverse slope assembly and jacking construction method according to the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the present invention during the second assembly;

[0035] Figure 3 This is a schematic diagram of the structure of the working condition 11 of the present invention after assembly;

[0036] Figure 4 This is a schematic diagram of the axis points of the steel box girder during assembly according to the present invention. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0038] like Figures 1 to 3 As shown in the figure, a method for assembling and pushing a curved steel box girder with a variable transverse slope according to the present invention comprises the following steps:

[0039] S1. Establish target alignment: According to the steel box girder design and construction drawings, establish the target plane and elevation alignment of the top surface of the steel box girder under each assembly condition. The target plane and elevation alignment include the beam axis and beam edge line.

[0040] S2. Calculate target values: Under each assembly condition, calculate the plane coordinates (x, y) and elevation (h) target values ​​of the top axis and edge points at the front and rear section sections of the steel box girder segment to be assembled;

[0041] S3. Assembly and adjustment on the first support: On the support in the steel beam assembly area, use the line connecting the axis point A of the first section and the axis point B of the tail section of the first assembly section as the spatial rotation axis to rotate the target linear structure in the direction of reducing the cross slope at the bottom of the beam. The rotation amount is determined by the difference between the design cross slope and the safe cross slope. After the rotation, the on-site linear control data (x, y, h) of the AB segment of the first assembly working condition is generated, and on-site adjustment and assembly are carried out accordingly.

[0042] In this embodiment, the transverse slope of the design drawing is 5%, which is adjusted to 3% during construction, a decrease of 2%. 2% is the difference between the design transverse slope and the safe transverse slope. The purpose is to control the transverse slope of the steel beam during assembly and jacking to not exceed 3% to ensure safety during assembly and jacking. Design cross slope Assembling safety slopes The direction of the difference is the direction with smaller slope.

[0043] S4. Pushing construction: Assemble the steel box beams according to the adjusted line shape, and use the reaction jacks arranged on the supports and piers with the function of moving the steel box beams longitudinally and transversely to push the beam sections to the target mileage;

[0044] S5, subsequent assembly: During the subsequent assembly, the target line shape is spatially rotated again with the line connecting the axis point B of the head section and the axis point C of the tail section of the segment to be assembled as the rotation axis. The rotation direction is also in the direction of reducing the cross slope, and the rotation amount is the same as step S3. After the rotation, the on-site line shape control data of the assembled and to-be-assembled steel box girders of the BC segment under this working condition are obtained;

[0045] S6, fine-tuning and assembly: Based on the linear control data from step S5, fine-tune the linear shape of the assembled steel box girder, assemble the segments to be assembled, and control the vertical rotation angle, lateral rotation angle and twist deviation between the segments. The geometric relationship between the assembled segments and the segments to be assembled is obtained by rotating the designed three-dimensional coordinates around the rotation axis by a certain amount;

[0046] S7, repeat construction: repeat steps S5 and S6 until all segments are assembled and pushed;

[0047] S8, beam drop and reset: Install permanent supports, drop the steel box beam to the design elevation, restore the beam bottom cross slope to the design state, and reset the beam bottom cross slope by adjusting the height of the permanent supports.

[0048] The spatial rotation of step S3 and step S5 is achieved by the following calculations:

[0049] Let the direction vector of the rotation axis L be u=( ), u is the direction vector, and the rotation axis passes through the point =( ), for any point P=(x,y,z), rotate around L by angle The coordinates are: Where R is the rotation matrix; is the rotation angle, is the coordinate of point P after rotation around the rotation axis L.

[0050] The calculation formula of the rotation matrix R is:

[0051] The rotation axis L is determined by the axis point A and the axis point B;

[0052] Take the coordinates of point B ( );

[0053] Direction vector

[0054] The steps for rotating a point P = (x, y, z) around the axis of rotation L are as follows:

[0055] a. Translation: translate point P to is the coordinate system with the origin;

[0056] b. Rotation: Apply the rotation matrix R to rotate ;

[0057] c. Inverse translation: the rotated point Translate back to the original coordinate system;

[0058] When the present invention is assembled for the first time, the line connecting point A (AK0+563.800) and point B (AK0+551.997) is used as the rotation axis, and then the rotation angle is obtained by reducing the corresponding cross slope by 2%. , apply the rotation formula to all points on the target line type of segment AB to obtain the rotated coordinates, such as the data adjusted by 2% in Table 2.

[0059] Rotation angle Calculated as follows:

[0060]

[0061] In the present invention .

[0062] During the second assembly, the rotation formula is applied to all points on the target line of segment BC with the line connecting points B (AK0+551.997) and C (AK0+539.995) as the rotation axis to obtain the rotated coordinates. The data is adjusted by 2% as shown in Table 2. Subsequent segments are assembled in sequence until the construction is completed. After the construction is completed, the cross slope of the bottom of the beam is restored to the designed 5% by adjusting the height of the permanent support.

[0063] As shown in Table 3, after adjustment, the cross slope of the beam is stable at about 3%, the actual cross slope value is 0.030-0.031, ΔX, ΔY, and ΔH are all within a reasonable range, and the coordinate deviation is controllable.

[0064] In the present invention, a guide beam is provided before the AB stage during the jacking process, and the steel box beam is supported by the guide beam. The provision of the guide beam enables the steel box beam to be stressed as quickly as possible during the jacking process.

[0065] like Figure 4 As shown, since the structure of the steel box girder is a fan-shaped structure, in the present invention, there is a deviation between the mileage of the two sides of the steel box girder and the reference line, that is, there is a deviation in the coordinates. Therefore, it is necessary not only to calculate the coordinate values ​​of the reference route, but also to calculate the coordinate values ​​of both sides of the steel box girder, that is, the coordinate values ​​corresponding to 5.242 on the left and 14.267 on the right.

[0066]

[0067] Table 1 is the reference table of the three-dimensional coordinates of the rotation axis when the design cross slope of segment numbers 11-16 is 5% in working condition 11

[0068]

[0069] Table 2 is the reference table of the three-dimensional coordinates of the rotation axis when the cross slope of segment numbers 11-16 is 3% in working condition 11

[0070]

[0071] Table 3 shows the deviation between Table 2 and Table 1 for segment numbers 11-16 in working condition 11

[0072] The implementation methods of the present invention are not limited to these. According to the above-mentioned embodiments of the present invention, by utilizing conventional technical knowledge and customary means in this field, without departing from the above-mentioned basic technical ideas of the present invention and without conflict, the above-mentioned preferred embodiments can also be modified, replaced or combined in various other forms. The other embodiments obtained all fall within the scope of protection of the present invention.

Claims

1. A method for assembling and pushing a curved steel box girder with a variable transverse slope, characterized by: The following steps are included: S1. Establish target line type: According to the steel box girder design and construction drawings, establish the target plane and elevation line type of the top surface of the steel box girder under each assembly condition. The target plane and elevation line type include the beam axis and the beam edge line; S2. Calculate target value: Under each assembly condition, calculate the plane coordinates (x, y) and elevation (h) target values ​​of the top surface axis, edge points at the front and rear section of the steel box girder segment to be assembled; S3. Assembly and adjustment on the first bracket: On the bracket in the steel beam assembly area, use the line connecting the first section axis point A and the tail section axis point B of the first assembly section as the spatial rotation axis to rotate the target linearity in space. The rotation direction is the direction of reducing the cross slope of the beam bottom. The rotation amount is determined by the difference between the design cross slope and the safe cross slope. After rotation, the on-site line type control data (x, y, h) of the AB segment of the first assembly condition is generated, and on-site adjustment and assembly are performed accordingly; S4. Pushing construction: According to the adjusted Linearly assemble the steel box girder, and use the reaction jacks with the function of longitudinally and transversely moving the steel box girder arranged on the brackets and piers to push the beam segment to the target mileage; S5, subsequent assembly: During the subsequent assembly, use the line connecting the head end section axis point B and the tail end section axis point C of the segment to be assembled as the rotation axis, and rotate the target line shape again in space. The rotation direction is also the direction of reducing the cross slope, and the rotation amount is the same as step S3. After the rotation, the on-site line shape control data of the BC segment that has been assembled and the steel box girder to be assembled under this working condition is obtained; S6, fine-tuning and assembly: According to the line shape control data of step S5, fine-tune the line shape of the assembled steel box girder, assemble the segment to be assembled, and control the vertical rotation angle, transverse rotation angle and twist deviation between the segments; S7, repeated construction: repeat steps S5 and S6 until all segments are assembled and pushed; S8, beam drop and reset: install permanent supports, drop the steel box girder to the design elevation, and restore the cross slope at the bottom of the beam to the design state.

2. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 1, characterized in that: The spatial rotation of step S3 and step S5 is realized by the following calculation; let the direction vector of the rotation axis L be u=( ), u is the direction vector, and the rotation axis passes through the point =( ), for any point P=(x,y,z), rotate around L by angle The coordinates are: Where R is the rotation matrix; is the rotation angle; is the coordinate of point P after rotation around the rotation axis L.

3. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 2, characterized in that: The calculation formula of the rotation matrix R is:

4. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 3, characterized in that: The rotation axis L is determined by the axis point A and the axis point B; Take the coordinates of point B ( ); direction vector .

5. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 4, characterized in that: The steps for rotating point P=(x,y,z) around the rotation axis L are as follows: a. Translation: Translate point P to is the coordinate system with the origin; b. Rotation: Apply the rotation matrix R to rotate ; c. Inverse translation: the rotated point Translate back to the original coordinate system; 6. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 1, characterized in that: The design cross slope is 5%, the safety cross slope is 3%, the rotation amount corresponds to a 2% cross slope reduction value, and the rotation angle Design cross slope Assembling safety slopes The direction of the difference is the direction of the smaller slope, that is 7. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 1, characterized in that: In step S6, the geometric relationship between the assembled segment and the segment to be assembled is obtained by rotating the designed three-dimensional coordinates around the rotation axis by a certain amount.

8. A method for assembling and pushing a curved steel box girder with a variable transverse slope according to claim 1, characterized in that: In step S8, the horizontal slope of the bottom of the beam is reset by adjusting the height of the permanent support.

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