Incremental launching construction method of bilateral box girder and bridge construction method

Abstract

The invention relates to the technical field of bridge construction, in particular to an incremental launching construction method of a bilateral box girder and a bridge construction method. The incremental launching construction method comprises the steps that the transverse overturning stability coefficient of a beam body is calculated, and the anti-overturning capacity of the beam body is judged according to the transverse overturning stability coefficient; according to the judgment result of the anti-overturning capacity of the beam body, temporary piers are constructed under inner webs of the beam body side boxes, or temporary piers are constructed under the inner webs and outer webs of the beam body side boxes at the same time; and the temporary piers are used for pushing the beam body to the designed position. According to the method, the anti-overturning capacity of the beam body is calculated and judged, the arrangement scheme of the temporary piers is flexibly adjusted, the temporary piers are only arranged below the inner web plate under the condition that the conditions are allowed for incremental launching construction, the gradually-widened outer web plate is ingeniously avoided, the number of the temporary piers is reduced, complex measures of incremental launching on a curve are also reduced, and the method is economical, safe and high in practicability. And the operability is high.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a jacking construction method for a double-sided box girder and a bridge construction method. Background Art

[0002] Push-slip construction is a method of engineering construction with a certain degree of flexibility such as bridges, roof trusses, and steel structures. For example, the Chinese invention application "Walking multi-point pushing construction method" (application number 201210042810.4) discloses the following content: The walking multi-point pushing scheme uses the two steps of "pushing" and "pushing" alternately. First, the whole steel box girder is lifted by the supporting jacking cylinder, and then it is pushed forward by the pushing cylinder, and then the steel box girder is placed on the temporary pier structure. The pushing cylinder is retracted to the bottom and continues to realize the next cycle. Through the cycle of reciprocating pushing steps, the steel box girder is finally sent to the predetermined position.

[0003] In the related technology, during the top-pushing construction of the double-sided box composite beam, it is necessary to first push the double-sided box steel beam, and then pour the concrete panel after the top-pushing is completed. The top-pushing requires setting up temporary piers between the main piers. Install the steel beam assembly bracket next to the starting pier, and use the gantry crane to assemble the steel box beam on the assembly bracket. After a part of the steel beam is assembled, it starts to push forward, and then continues to assemble the steel beam on the assembly bracket, and the steel beam top-pushing construction is carried out in a cycle.

[0004] However, the traditional double-sided box composite beam or steel box beam jacking is to set a walking top under the inner and outer webs of the side box, and a temporary pier needs to be set under the walking top. For some side boxes with special structures (for example: steel box beams that gradually widen), the principle of widening the side boxes is that the inner webs of the two side boxes are parallel to the bridge axis, and the outer webs are gradually widening. Therefore, the jacking construction of such side boxes requires a large temporary pier under the inner and outer webs that can simultaneously meet the needs of the inner and outer webs, or a temporary pier is set for each of the inner and outer webs. The temporary piers use a lot of materials, have complicated installation measures, occupy a lot of space, are expensive and uneconomical. Summary of the invention

[0005] In the related technologies, the construction of double-sided box composite beams or steel box beams is done by default by constructing large temporary piers under the inner and outer webs or by constructing multiple temporary piers to push the inner and outer webs at the same time. This results in the use of more materials for the temporary piers, complex installation measures, more space occupied, and high costs and uneconomical problems.

[0006] In a first aspect, an embodiment of the present application provides a method for jacking construction of a double-sided box girder, which comprises:

[0007] Calculate the lateral overturning stability coefficient of the beam body, and judge the anti-overturning capacity of the beam body based on the lateral overturning stability coefficient;

[0008] According to the result of the anti-overturning capacity assessment of the beam body, temporary piers are constructed under the inner web of the beam body side box, or temporary piers are constructed under both the inner web and outer web of the beam body side box;

[0009] Use temporary piers to push the beam to the designed position.

[0010] In combination with the first aspect, in one implementation, the calculating the lateral overturning stability coefficient of the beam body includes:

[0011] Calculate the overturning moment and resisting moment of the beam;

[0012] The ratio of the resisting moment to the overturning moment is taken as the lateral overturning stability coefficient.

[0013] In combination with the first aspect, in one implementation, the calculating the overturning moment of the beam body includes:

[0014] Measuring the first distance value from the point where the resultant force of the wind load acts on the beam to the overturning point of the beam and the magnitude of the resultant force of the wind load;

[0015] The product of the first distance value and the resultant wind load is taken as the overturning moment.

[0016] In combination with the first aspect, in one implementation, the calculation of the resisting moment of the beam includes:

[0017] Measuring a second distance value from the point of action of the gravity of the beam and the resultant force of the gravity of the beam to its overturning point;

[0018] The product of the gravity of the beam and the second distance value is taken as the resisting moment.

[0019] In combination with the first aspect, in one embodiment, constructing temporary piers under the inner web of the beam side box includes: arranging a plurality of temporary piers at intervals under the inner web of the beam side box along the length direction of the beam.

[0020] In combination with the first aspect, in one embodiment, the multiple temporary piers are arranged at intervals under the inner webs of the side boxes of the beam body along the length direction of the beam body, including: multiple temporary pier groups are arranged in groups of two temporary piers under the two inner webs of the side boxes of the beam body along the length direction of the beam body, and the line connecting the centers of the multiple temporary pier groups is parallel to the bridge axis of the beam body.

[0021] In combination with the first aspect, in one embodiment, before constructing a temporary pier under the inner web of the beam side box, the method further includes: constructing a main pier and installing an assembly bracket on the main pier.

[0022] In combination with the first aspect, in one embodiment, the construction of a temporary pier under the inner web of the beam side box further includes:

[0023] Construct pads and walking tops on temporary piers;

[0024] And assemble the beam body on the assembly bracket.

[0025] In combination with the first aspect, in one implementation, the step of using a temporary pier to push the beam body to a designed position includes:

[0026] Use the walking jack to push the beam body and move it one stroke, then drop the beam body onto the pad, and the walking jack will retreat one stroke;

[0027] Use walking jack to repeat the jacking steps until the beam reaches the designed position.

[0028] In a second aspect, an embodiment of the present application provides a bridge construction method, which includes: a jacking construction method as described in any one of the above.

[0029] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0030] This application calculates and determines the anti-overturning capacity of the beam body, flexibly adjusts the layout of temporary piers, and only sets temporary piers under the inner web when conditions permit for jacking construction, cleverly avoiding the gradually widening outer web, reducing the number of temporary piers, and also reducing the complex measures of jacking on curves. It is economical, safe, and highly operational. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 This is a flow chart of the top-pushing construction method of the double-sided box girder in the embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of the force on the beam body in the embodiment of the present application;

[0034] Figure 3 This is a longitudinal cross-sectional view of the beam body after step S2 is completed in one embodiment of the present application;

[0035] Figure 4 This is a schematic diagram of a beam body during a top-pushing construction process in one embodiment of the present application;

[0036] Figure 5 This is a schematic diagram of a beam body from a top-down perspective during the jacking construction process in one embodiment of the present application.

[0037] In the figure: 1. Beam body; 11. Inner web; 12. Outer web; 2. Temporary pier; 3. Main pier; 6. Walking top. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In the related technologies, the construction of double-sided box composite beams or steel box beams is done by default by constructing large temporary piers under the inner and outer webs or by constructing multiple temporary piers to push the inner and outer webs at the same time. This results in the use of more materials for the temporary piers, complex installation measures, more space occupied, and high costs and uneconomical problems.

[0040] First, as Figure 1 As shown, the present application provides a method for top-pushing construction of a double-sided box girder, which comprises:

[0041] Step S1, calculating the lateral overturning stability coefficient of the beam body 1, and judging the anti-overturning ability of the beam body 1 according to the lateral overturning stability coefficient.

[0042] In some specific implementations, the above step S1 includes:

[0043] Step S1a, calculating the overturning moment and the resisting moment of the beam body 1.

[0044] Specifically, Figure 2 As shown, the first distance value L1 from the point where the wind load resultant force acts on the beam body 1 to the overturning point of the beam body 1 and the magnitude of the wind load resultant force F1 are measured. The gravity F2 of the beam body 1 and the second distance value L2 from the point where the gravity resultant force of the beam body 1 acts to its overturning point are measured. The product of the first distance value L1 and the wind load resultant force F1 is taken as the overturning moment, and the product of the gravity F2 of the beam body 1 and the second distance value L2 is taken as the resisting moment.

[0045] Step S1b: Taking the ratio of the resisting moment to the overturning moment as the lateral overturning stability coefficient

[0046] Specifically, the lateral overturning stability coefficient G is calculated according to the formula:

[0047] G = (F2 × L2) / (F1 × L1)

[0048] Among them, F2 is the gravity of beam body 1, L2 is the second distance value from the point of action of the combined force of the gravity F2 of beam body 1 and the gravity of beam body 1 to its overturning point, F1 is the combined force of wind load, and L1 is the first distance value from the point of action of the combined force of wind load on beam body 1 to the overturning point of beam body 1.

[0049] Step S1c: judging the anti-overturning capability of the beam body 1 according to the lateral overturning stability coefficient.

[0050] It is worth noting that the lateral overturning stability coefficient is used to evaluate the beam body 1 and provide a basis for the selection of subsequent jacking construction.

[0051] In some preferred implementations, when the lateral overturning stability coefficient is greater than a preset threshold, it can be evaluated that the beam body 1 meets the requirement of pushing only the inner web 11 .

[0052] In some optional implementations, the preset threshold value may be set to 1.3, that is, the lateral overturning stability coefficient must be greater than 1.3, that is, when the resisting moment is 1.3 times or more of the overturning moment, it is determined that the beam body 1 meets the preset requirements.

[0053] It is understandable that the main factor affecting the lateral overturning of steel beams is the lateral wind load, and steel beams mainly rely on their own gravity to resist the lateral wind load.

[0054] It should be noted that there are two supporting points for a single web jacking section, and four supporting points for an inner and outer web jacking section. During the jacking process, the height of the step top pad is high. In the traditional concept, the transverse stability of the bridge is worse than that of the four-point support, and there is a risk of tipping to one side. After research and analysis, the steel box girder has a large width-to-height ratio, and the transverse stability of the entire steel beam is relatively good. After calculation, the safety factor of the transverse stability of the two-point support meets the requirements.

[0055] Step S2, according to the judgment result of the anti-overturning capacity of the beam body 1, construct a temporary pier 2 under the inner web 11 of the side box of the beam body 1, or construct a temporary pier 2 under the inner web 11 and the outer web 12 of the side box of the beam body 1 at the same time.

[0056] The above step S2 comprises:

[0057] Step S2a, such as Figure 4 As shown, the main pier 3 is constructed and an assembling bracket is installed on the main pier 3.

[0058] Step S2b, arrange multiple temporary piers 2 at intervals under the inner web 11 of the side box of the beam body 1 along the length direction of the beam body 1, or arrange multiple temporary piers 2 at intervals under the inner web 11 and outer web 12 of the side box of the beam body 1 along the length direction of the beam body 1.

[0059] Specifically, Figure 3 and Figure 5As shown, multiple temporary pier groups are arranged in groups of two or four temporary piers 2 under the two inner webs 11 of the side boxes of the beam body 1 along the length direction of the beam body 1, and the connecting line of the centers of the multiple temporary pier groups is parallel to the bridge axis of the beam body 1.

[0060] Step S2c, constructing the pad and the step top 6 on the temporary pier 2, and assembling the beam body 1 on the assembly bracket.

[0061] Step S3: Use the temporary pier 2 to push the beam body 1 to the designed position.

[0062] Specifically, the walking top 6 on the assembled bracket is used to lift the beam body 1 and push it forward for a stroke. The beam body 1 is supported on the pad next to the walking top 6. The walking top 6 retreats for a stroke, and the walking top 6 lifts the beam body 1 to prepare for the next stroke push, and the beam body 1 is pushed in a cycle in sequence.

[0063] It is worth noting that the traditional double-sided box composite beam or steel box beam jacking is to set a walking top under the inner and outer webs of the side box, and a temporary pier 2 needs to be set under the walking top 6. The outer web 12 is gradually widening, so it is necessary to set a large temporary pier that can meet the needs of both the inner and outer webs under the inner and outer webs, or set a temporary pier 2 for each of the inner and outer webs. The temporary pier 2 uses a lot of materials, and the material consumption is 3 to 4 times that of the single web jacking. The installation measures are complicated, the site is occupied, and the cost is high and uneconomical. Furthermore, the inner webs 11 of the two side boxes are parallel to the bridge axis, so only the walking top 6 and the temporary pier 2 are set under the inner webs 11. Since the inner webs 11 are parallel and consistent with the jacking trajectory, the temporary pier 2 only needs to meet the jacking of the two parallel inner webs 11. The jacking trajectory is simple and clear, easy to operate, safe and reliable. The outer web is gradually getting wider. If walking tops and temporary piers are set on both the inner and outer webs, the pushing trajectory will be complicated, and the state of the walking tops needs to be adjusted at any time. The complicated operation affects the construction period and safety is difficult to guarantee.

[0064] In a second aspect, the present application provides a bridge construction method for a double-sided box girder, which includes: a top-pushing construction method for a double-sided box girder, the method comprising:

[0065] Step S1, calculating the lateral overturning stability coefficient of the beam body 1, and judging the anti-overturning ability of the beam body 1 according to the lateral overturning stability coefficient.

[0066] In some specific implementations, the above step S1 includes:

[0067] Step S1a, calculating the overturning moment and the resisting moment of the beam body 1.

[0068] Specifically, Figure 2As shown, the first distance value L1 from the point where the wind load resultant force acts on the beam body 1 to the overturning point of the beam body 1 and the magnitude of the wind load resultant force F1 are measured. The gravity F2 of the beam body 1 and the second distance value L2 from the point where the gravity resultant force of the beam body 1 acts to its overturning point are measured. The product of the first distance value L1 and the wind load resultant force F1 is taken as the overturning moment, and the product of the gravity F2 of the beam body 1 and the second distance value L2 is taken as the resisting moment.

[0069] Step S1b: Taking the ratio of the resisting moment to the overturning moment as the lateral overturning stability coefficient

[0070] Specifically, the lateral overturning stability coefficient G is calculated according to the formula:

[0071] G = (F2 × L2) / (F1 × L1)

[0072] Among them, F2 is the gravity of beam body 1, L2 is the second distance value from the point of action of the combined force of the gravity F2 of beam body 1 and the gravity of beam body 1 to its overturning point, F1 is the combined force of wind load, and L1 is the first distance value from the point of action of the combined force of wind load on beam body 1 to the overturning point of beam body 1.

[0073] Step S1c: judging the anti-overturning capability of the beam body 1 according to the lateral overturning stability coefficient.

[0074] It is worth noting that the lateral overturning stability coefficient is used to evaluate the beam body 1 and provide a basis for the selection of subsequent jacking construction.

[0075] In some preferred implementations, when the lateral overturning stability coefficient is greater than a preset threshold, it can be evaluated that the beam body 1 meets the requirement of pushing only the inner web 11 .

[0076] In some optional implementations, the preset threshold value may be set to 1.3, that is, the lateral overturning stability coefficient must be greater than 1.3, that is, when the resisting moment is 1.3 times or more of the overturning moment, it is determined that the beam body 1 meets the preset requirements.

[0077] It is understandable that the main factor affecting the lateral overturning of steel beams is the lateral wind load, and steel beams mainly rely on their own gravity to resist the lateral wind load.

[0078] It should be noted that there are two supporting points for a single web jacking section, and four supporting points for an inner and outer web jacking section. During the jacking process, the height of the step top pad is high. In the traditional concept, the transverse stability of the bridge is worse than that of the four-point support, and there is a risk of tipping to one side. After research and analysis, the steel box girder has a large width-to-height ratio, and the transverse stability of the entire steel beam is relatively good. After calculation, the safety factor of the transverse stability of the two-point support meets the requirements.

[0079] Step S2, according to the judgment result of the anti-overturning capacity of the beam body 1, construct a temporary pier 2 under the inner web 11 of the side box of the beam body 1, or construct a temporary pier 2 under the inner web 11 and the outer web 12 of the side box of the beam body 1 at the same time.

[0080] The above step S2 comprises:

[0081] Step S2a, such as Figure 4 As shown, the main pier 3 is constructed and an assembling bracket is installed on the main pier 3.

[0082] Step S2b, arrange multiple temporary piers 2 at intervals under the inner web 11 of the side box of the beam body 1 along the length direction of the beam body 1, or arrange multiple temporary piers 2 at intervals under the inner web 11 and outer web 12 of the side box of the beam body 1 along the length direction of the beam body 1.

[0083] Specifically, Figure 3 and Figure 5 As shown, multiple temporary pier groups are arranged in groups of two or four temporary piers 2 under the two inner webs 11 of the side boxes of the beam body 1 along the length direction of the beam body 1, and the connecting line of the centers of the multiple temporary pier groups is parallel to the bridge axis of the beam body 1.

[0084] Step S2c, constructing the pad and the step top 6 on the temporary pier 2, and assembling the beam body 1 on the assembly bracket.

[0085] Step S3: Use the temporary pier 2 to push the beam body 1 to the designed position.

[0086] Specifically, the walking top 6 is used to lift the beam 1 and push it forward for a stroke. The beam 1 is supported on the pad next to the walking top 6. The walking top 6 retreats for a stroke, and the walking top 6 lifts the beam 1 to prepare for the next stroke push. The beam 1 is pushed in a cycle in sequence until it reaches the designed position.

[0087] In summary, the traditional double-sided box composite beam or steel box beam jacking is to set a walking top under the inner and outer webs of the side box, and a temporary pier 2 needs to be set under the walking top 6. The outer web 12 is gradually widening, so it is necessary to set a large temporary pier that can meet the needs of both the inner and outer webs under the inner and outer webs, or set a temporary pier 2 for each of the inner and outer webs. The temporary pier 2 uses a lot of materials, and the material consumption is 3 to 4 times that of the single web jacking. The installation measures are complicated, the site is occupied, and the cost is high and uneconomical. Furthermore, the inner webs 11 of the two side boxes are parallel to the bridge axis, so only the walking top 6 and the temporary pier 2 are set under the inner webs 11. Since the inner webs 11 are parallel and consistent with the jacking trajectory, the temporary pier 2 only needs to meet the jacking of the two parallel inner webs 11. The jacking trajectory is simple and clear, easy to operate, safe and reliable. The outer web is gradually getting wider. If walking tops and temporary piers are set on both the inner and outer webs, the pushing trajectory will be complicated, and the state of the walking tops needs to be adjusted at any time. The complicated operation affects the construction period and safety is difficult to guarantee.

[0088] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0089] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0090] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for pushing construction of a double-sided box girder, characterized in that: include: Calculating the transverse overturning stability coefficient of the beam body (1), and judging the anti-overturning capacity of the beam body (1) according to the transverse overturning stability coefficient; According to the result of the judgment on the anti-overturning capacity of the beam body (1), a temporary pier (2) is constructed under the inner web (11) of the side box of the beam body (1), or a temporary pier (2) is constructed simultaneously under the inner web (11) and the outer web (12) of the side box of the beam body (1); The beam body (1) is pushed to the designed position using temporary piers (2).

2. The jacking construction method according to claim 1, characterized in that: The calculation of the lateral overturning stability coefficient of the beam body (1) comprises: Calculate the overturning moment and resisting moment of the beam (1); The ratio of the resisting moment to the overturning moment is taken as the lateral overturning stability coefficient.

3. The jacking construction method according to claim 2, characterized in that: The calculation of the overturning moment of the beam body (1) comprises: Measuring a first distance value from a point where the resultant force of the wind load acts on the beam body (1) to a tipping point of the beam body (1) and the magnitude of the resultant force of the wind load; The product of the first distance value and the resultant wind load is taken as the overturning moment.

4. The jacking construction method according to claim 2, characterized in that: The calculation of the resisting moment of the beam body (1) comprises: Measuring the gravity of the beam body (1) and a second distance value from the point where the combined gravity of the beam body (1) acts to its overturning point; The product of the gravity of the beam (1) and the second distance value is taken as the resisting moment.

5. The jacking construction method according to claim 2, characterized in that: The construction of a temporary pier (2) under the inner web (11) of the side box of the beam body (1) comprises: arranging a plurality of temporary piers (2) at intervals under the inner web (11) of the side box of the beam body (1) along the length direction of the beam body (1).

6. The jacking construction method according to claim 5, characterized in that: The method comprises: arranging a plurality of temporary piers (2) at intervals along the length direction of the beam body (1) under the inner webs (11) of the side boxes of the beam body (1), comprising: arranging a plurality of temporary pier groups in a group of two temporary piers (2) under the two inner webs (11) of the side boxes of the beam body (1) along the length direction of the beam body (1), and the connecting line of the centers of the plurality of temporary pier groups is parallel to the bridge axis of the beam body (1).

7. The jacking construction method according to claim 6, characterized in that: Before constructing the temporary pier (2) under the inner web (11) of the side box of the beam body (1), the method further includes: constructing the main pier (3) and installing an assembly bracket on the main pier (3).

8. The jacking construction method according to claim 7, characterized in that: The method of constructing a temporary pier (2) under the inner web (11) of the side box of the beam body (1) further comprises: Constructing a pad and a walking top (6) on the temporary pier (2); The beam body (1) is assembled on the assembly bracket.

9. The jacking construction method according to claim 8, characterized in that: The method of using the temporary pier (2) to push the beam body (1) to the designed position comprises: The beam body (1) is pushed by the walking top (6) to move a stroke, and then the beam body (1) is placed on the copying pad, and the walking top (6) is retreated a stroke; Use the walking jack (6) to repeat the pushing steps until the beam (1) reaches the designed position.

10. A bridge construction method, characterized in that: include: A jacking construction method as described in any one of claims 1 to 9.

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