Overpass bridge full-section incremental launching construction device, construction method and control calculation method

Abstract

The invention discloses an overpass bridge full-section incremental launching construction device and method and a control calculation method. The overpass bridge full-section incremental launching construction device comprises an incremental launching platform, and the incremental launching platform is arranged on a newly-built roadbed line; the sliding rail is arranged on the pushing platform; the pushing device is arranged on the sliding rail; the front and rear guide beams are arranged on the pushing device; the multi-time tensioning anchorage devices are arranged on the front guide beam and the rear guide beam; the external pre-stressed steel beam is connected with the multi-tensioning anchorage device; the steering block is connected with the external prestressed steel beam; the support is arranged at the lower end of the steering block; and the cross beam is connected with the support. Compared with the prior art, the pushing device has the advantages that overlarge horizontal thrust cannot be generated on the beam body in the pushing process, meanwhile, the repeated jacking and descending process of the pushing device is omitted through consolidation of the pushing device and the beam body, the overturning risk increased in the jacking process is reduced, and the large horizontal thrust generated on the beam body in the pushing process is evenly distributed in the beam body.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering and bridge construction, and in particular to a full-section jacking construction device, a construction method and a control calculation method for a cross-line bridge. Background Art

[0002] With the growing demand for national transportation infrastructure, the reconstruction and expansion of existing highways has become a key direction in the current highway field. The reconstruction and expansion projects often involve the construction of cross-line bridges. In order to reduce the impact of cross-line bridge construction on the existing traffic under the bridge, the jacking construction method is often used.

[0003] At present, there are many studies and applications of top-pushing construction in concrete bridge structures and steel-concrete composite bridge structures. It is often used in the segmental top-pushing construction of multi-span continuous beams. There is less research on the overall top-pushing construction technology of simply supported cross-line bridges that do not interrupt traffic under the bridge. There are few cases of overall top-pushing construction implementation for single-span composite beam bridges at home and abroad, such as those over highways, and there is no mature experience to learn from, and there are few corresponding technical standards to guide construction.

[0004] Under the condition of not interrupting the traffic under the bridge, the risk of full-section jacking of simply supported composite beam cross-line bridges is relatively high. The overturning stability and bridge deck cracking problems during the jacking process are prominent, which will seriously affect the quality and safety of bridge construction. If the beam-making platform is not long enough due to site restrictions in actual projects, conventional jacking construction cannot be carried out.

[0005] In the prior art, temporary cable tensioning or rear-end weighting is often used to solve the overturning stability problem during the jacking process. However, the increase in jacking weight caused by the construction of temporary cable towers and weighting will undoubtedly increase the construction cost, and the cable force regulation and counterweight load are difficult to control.

[0006] Although the drag-type jacking construction ensures the overturning stability of the beam during the jacking process, the large horizontal force used in the construction of concrete structure bridges during the jacking process is prone to cracking risks. It is currently commonly used in the construction of pure steel structure bridges such as steel trusses and steel boxes. Its advantage is that the horizontal jacking force mainly overcomes the friction between the beam and the slideway. There is no support system conversion in the jacking process of the structure during the jacking stage, and the risk of jacking overturning is relatively low.

[0007] The walking jacking process is often used in the jacking construction of continuous beams. The main beam is lifted by a jacking device for walking reciprocating motion. It mainly solves the problem of excessive horizontal thrust on the beam body during dragging jacking construction. However, in order to achieve the reciprocating motion of the jacking device, there is no constraint between the jacking device and the beam body. The overturning stability of the beam body is provided by its own weight, which increases the risk of overturning of the beam body during jacking. Or the beam body needs to be overloaded, which increases the rated power of the walking jacking device and increases the construction cost.

[0008] The aforementioned construction scenario is often encountered in the construction of cross-line bridges, where the jacking span is large and the beam-making platform is insufficient. The main reason for the increased risk of jacking is that the force at the junction of the guide beam and the jacking beam is unclear and the rigidity of the overall structure is small. The larger vertical displacement at the front end of the longer guide beam also does not meet the requirements of the specification. Among the existing technical solutions, the use of adding temporary cable towers to control the deflection of the front section of the guide beam will undoubtedly increase the construction cost. In addition, adding temporary cable towers will undoubtedly increase the clearance height above the bridge, and there are restrictions on its use when it is necessary to cross the highway or pass under an obstacle.

[0009] The advantage of the full-section top-pushing construction of composite beams is that the composite beams (including steel guardrails) are all manufactured outside the span of the bridge. After the composite section is formed, the whole is pushed up to the beam drop to form a bridge. There is no need to carry out wet work in the spanning area. The bridge can be put into operation after the bridge deck is paved. The promotion of this process will help further develop the top-pushing construction technology of cross-line bridges and solve the urgent need for the construction of cross-line bridges without interrupting the traffic under the bridge. The existing technology cannot solve the problem of realizing the rapid top-pushing construction of cross-line bridges in a relatively convenient way without interrupting the traffic under the bridge, resulting in limitations in the application of top-pushing construction in cross-line bridges.

[0010] In summary, there is at least one of the following technical problems:

[0011] The existing technology cannot solve the problem of realizing the rapid jacking construction of cross-line bridges in a relatively convenient manner without interrupting the traffic under the bridge, resulting in limitations in the application of jacking construction in cross-line bridges. Summary of the invention

[0012] The main purpose of the present invention is to provide a full-section jacking construction device for a cross-line bridge and a control calculation method thereof, so as to solve the problem that the prior art cannot realize the rapid jacking construction of the cross-line bridge more conveniently without interrupting the traffic under the bridge, resulting in limitations in the application of jacking construction in cross-line bridges.

[0013] In order to achieve the above object, according to one aspect of the present invention, a full-section jacking construction device for a cross-line bridge is provided, comprising:

[0014] A jacking platform, wherein the jacking platform is arranged on the newly built roadbed;

[0015] A slide rail, wherein the slide rail is arranged on the push platform;

[0016] A pushing device, wherein the pushing device is arranged on the slide rail;

[0017] Front and rear guide beams, the front and rear guide beams are arranged on the jacking device;

[0018] Multiple tensioning anchors, the multiple tensioning anchors are arranged on the front and rear guide beams;

[0019] An external prestressed steel strand, wherein the external prestressed steel strand is connected to a multiple tensioning anchor;

[0020] A steering block connected to an external prestressed steel strand;

[0021] A support, the support being arranged at the lower end of the steering block;

[0022] A crossbeam is connected to the support.

[0023] Preferably, it also includes steel guardrails and steel-UHPC composite beams, and cross beams are provided between the steel guardrails.

[0024] Preferably, the pushing device adopts an intelligent integrated pushing device, which includes a rail clamping pushing device, an anti-overturning electromagnetic device and a slide device. The intelligent integrated pushing device is symmetrically fixed to the bottom of the steel-UHPC composite beam to perform lateral limitation during the pushing process of the composite beam.

[0025] Preferably, the slide rail adopts a double I-shaped structure, and the intelligent integrated pushing device cooperates with the slide rail through a heavy-load roller group and limits the vertical displacement of the steel-UHPC composite beam to serve as an anti-overturning safety reserve during the pushing process.

[0026] Preferably, a vertical jack is arranged between the jacking platform and the bottom of the beam to support the deadweight of the beam, and the front guide beam adopts a short guide beam according to site restrictions.

[0027] According to another aspect of the present invention, a construction method of a full-section jacking construction device for a cross-line bridge is provided, comprising:

[0028] Step 1: Build the push platform and install the push rail;

[0029] Step 2: Assemble the channel steel beam outside the bridge site, install the front guide beam, and install the prefabricated UHPC bridge deck to form a steel-UHPC composite beam;

[0030] Step 3: Install the intelligent integrated jacking device at the bottom of the steel box girder, install the external prestressing device and the turning block, install the crossbeam on the steel guardrail, set up temporary support, and prepare for jacking;

[0031] Step 4: The jacking device pushes the entire section of the steel-UHPC composite beam forward, and when the front guide beam is fully pushed to the cantilever state, the external prestressing device is tensioned once and continues to be pushed forward;

[0032] Step 5: When the overturning stability of the steel-UHPC composite beam reaches the critical control requirements, install the rear guide beam at the rear end of the composite beam, and install the intelligent integrated jacking equipment at the bottom of the rear guide beam; tension the external prestress for the second time, and continue to push forward;

[0033] Step 6: After the front guide beam is pushed to the opposite bank, the external prestressing force is tensioned three times, and the deflection of the front guide beam is controlled to push it to the receiving pier or abutment on the opposite bank for shelving;

[0034] Step 7: Remove the extracorporeal prestressing measures, continue pushing, and complete the system conversion and beam drop.

[0035] Preferably, when the length of the beam is insufficient due to terrain restrictions, the pushing platform first pushes part of the beam ends and the leading beam, and completes the production of the entire composite beam when the leading beam is pushed to a sufficient length for the subsequent beam section.

[0036] Preferably, the external prestressing force adopts multiple tensioning anchors, which are anchored to the front guide beam and the rear guide beam respectively; a crossbeam and a temporary support are arranged on the steel guardrail, and a steering block is installed to correct the tensioning angle of the prestressed steel strands, improve the efficiency of prestressing, and avoid the risk of cracking caused by excessive tensile stress of the UHPC bridge deck in the cantilever state of the composite beam with the bridge deck;

[0037] The external prestressing tensile stress δ e The control value should satisfy the following formula:

[0038]

[0039] In the formula, L, q z 、E z I z are the length, weight and stiffness of the main beam respectively; L d ,q d 、E d I d are the guide beam weight and stiffness respectively; A e ,δ e are the cross-sectional area of ​​the external prestressed steel strand and the control value of the tension stress; δ max is the maximum tensile stress of UHPC bridge deck; [δ] is the design value of tensile stress strength of UHPC bridge deck; α is the angle between the external prestressed steel tendon and the horizontal direction.

[0040] According to another aspect of the present invention, a control calculation method for construction of a full-section jacking construction device for a cross-line bridge is provided, comprising:

[0041] Step 1: Calculate the stage when the cantilever state overturns during the composite beam jacking process, assuming that in the critical state of overturning, except for the outermost support under compression, the other supports are empty;

[0042] Step 2: Perform force analysis according to the analytical method. To simplify the force analysis, the overturning stability coefficient is used as the boundary and divided into two stages. In one stage, the overturning stability coefficient is less than the specified requirement. At this time, the top-pushing process begins to have the risk of overturning. In the other stage, the overturning stability coefficient is the smallest. At this time, the overturning risk of the top-pushing process is the greatest.

[0043] Step 3: The control value of the magnetic attraction force F corresponding to any cantilever length x of the top-pushing main beam from the time when there is a risk of overturning during the top-pushing process to the time when the risk of overturning during the top-pushing process is the maximum is:

[0044]

[0045] The weight and stiffness of the guide beam and the main beam are evenly distributed, K is the required overturning stability coefficient, and the length, weight and stiffness of the main beam are L, q respectively. z 、E z I z , the guide beam weight and stiffness are L d ,q d 、E d I d , the length, weight and stiffness of the counterweight beam are respectively; L p ,q p 、E p I p ;

[0046] Step 4: According to the two stages divided in step 2, the corresponding magnetic attraction control values ​​F1 and F2 are calculated, and the magnetic attraction control values ​​are calculated according to the envelope classification.

[0047] Preferably, the control value of the overturning stability coefficient is often taken as 1.5 to ensure that the composite beam will not overturn. Referring to the other calculation steps, the control value of the magnetic attraction force F of the anti-overturning electromagnetic device at each stage is obtained. The magnetic attraction control value can be designed according to the envelope classification to reduce the adjustment of the magnetic attraction force of the anti-overturning electromagnetic device during the construction process; the intelligent construction control system can also be used for dynamic adjustment, and the design value of the maximum rated suction force of the anti-overturning electromagnetic device is 1.5 times the required maximum control value.

[0048] The application of the technical solution of the present invention has the following technical effects:

[0049] The present invention is an improvement and innovation of the walking-type jacking process and the dragging-type jacking process to adapt to the application scenario of the full-section integral jacking construction of a single-span steel-UHPC composite bridge without interrupting the traffic under the bridge. Compared with the walking-type jacking process, its advantage is that it inherits the characteristic of not generating excessive horizontal thrust on the beam body during the jacking process, and through the consolidation of the jacking device and the beam body, it cancels the repeated jacking and lowering process to reduce the risk of overturning during the jacking process; compared with the dragging-type jacking process, its advantage is that it cancels the single-point jacking or single-point traction in the dragging-type jacking process, and uses a multi-point synchronous jacking system to evenly distribute the large horizontal thrust generated on the beam body during the jacking process in the beam body. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0051] Figure 1 It shows a schematic structural diagram of a full-section jacking construction device for a cross-line bridge according to the present invention;

[0052] Figure 2 Shows Figure 1 The front view of the full-section jacking construction device for the cross-line bridge;

[0053] Figure 3 Shows Figure 1 A top view of the full-section jacking construction device for the cross-line bridge;

[0054] Figure 4 Shows Figure 1 The left side view of the full section jacking construction device of the cross-line bridge;

[0055] Figure 5 Shows Figure 1 The first construction process view of the full-section jacking construction device of the cross-line bridge;

[0056] Figure 6 Shows Figure 1 The second construction process view of the full-section jacking construction device of the cross-line bridge;

[0057] Figure 7 Shows Figure 1 The third construction process view of the full-section jacking construction device of the cross-line bridge;

[0058] Figure 8 Shows Figure 1 The fourth construction process view of the full-section jacking construction device of the cross-line bridge;

[0059] Fig. 9 Shows Figure 1A side view of the full-section jacking construction device for the cross-line bridge;

[0060] Fig.10 Shows Figure 1 A three-dimensional view of the full-section jacking construction device for the cross-line bridge;

[0061] Fig.11 Shows Figure 1 A front view of the rail clamping and pushing device of the full-section pushing construction device for the cross-line bridge;

[0062] Fig.12 Shows Figure 1 The left side view of the rail clamping and pushing device of the full section pushing construction device of the cross-line bridge;

[0063] Fig.13 Shows Figure 1 A top view of the rail clamping and pushing device of the full-section pushing construction device for the cross-line bridge;

[0064] Fig.14 Shows Figure 1 A bottom view of the rail clamping and pushing device of the full-section pushing construction device of the cross-line bridge;

[0065] Fig.15 Shows Figure 1 The right side view of the rail clamping and pushing device of the full section pushing construction device of the cross-line bridge;

[0066] Fig.16 Shows Figure 1 Construction force analysis view of the full-section jacking construction device of the cross-line bridge.

[0067] The above drawings include the following reference numerals:

[0068] Externally prestressed steel strand 1; crossbeam 2; steering block 3; support 4; multiple tensioning anchor 5; counterweight rear guide beam 6; jacking device 7; slide rail 8; jacking platform 9; steel-UHPC composite beam 10; steel guardrail 11; front and rear guide beams 12; newly built roadbed 13; uninterrupted expressway 14; rail clamping device 15; longitudinal hydraulic rod 16; longitudinal hydraulic cylinder 17; heavy-duty roller group 18; anti-overturning electromagnetic device 19; transverse hydraulic rod 20; transverse hydraulic cylinder 21. DETAILED DESCRIPTION

[0069] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0070] like Figures 1 to 16As shown, an embodiment of the present invention provides a full-section jacking construction device for a cross-line bridge, including: a jacking platform 9, which is arranged on a newly built roadbed 13; a slide rail 8, which is arranged on the jacking platform 9; a jacking device 7, which is arranged on the slide rail 8; front and rear guide beams 12, which are arranged on the jacking device 7; multiple tensioning anchors 5, which are arranged on the front and rear guide beams 12; an external prestressed steel bundle 1, which is connected to the multiple tensioning anchors 5; a steering block 3, which is connected to the external prestressed steel bundle 1; a support 4, which is arranged at the lower end of the steering block 3; and a crossbeam 2, which is connected to the support 4.

[0071] In this embodiment, the jacking platform 9 is arranged on the newly built roadbed 13; a vertical jack is arranged between the jacking platform 9 and the bottom of the beam to support the deadweight of the beam body, and the front guide beam adopts a short guide beam according to the site restrictions. The slide rail 8 is arranged on the jacking platform 9; the slide rail 8 adopts a double I-shaped structure, and the intelligent integrated jacking equipment cooperates with the slide rail 8 through a heavy-loaded roller group, and limits the vertical displacement of the steel-UHPC composite beam 10 to serve as an anti-overturning safety reserve during the jacking process. The jacking device 7 is arranged on the slide rail 8; the jacking device 7 adopts an intelligent integrated jacking device 7, and the intelligent integrated jacking device 7 includes a rail clamping jacking device 7, an anti-overturning electromagnetic device and a slideway device. The intelligent integrated jacking device 7 is symmetrically fixed to the bottom of the steel-UHPC composite beam 10, and performs lateral limitation during the jacking process of the composite beam. Front and rear guide beams 12 are arranged on the jacking device 7; multiple tension anchors 5 are arranged on the front and rear guide beams 12; external prestressed steel bundles 1, the external prestressed steel bundles 1 are connected to the multiple tension anchors 5; the steering block 3 is arranged on the external prestressed steel bundles 1; the support 4 is arranged at the lower end of the steering block 3; the crossbeam 2 is connected to the support 4. It also includes steel guardrails 11 and steel-UHPC composite beams 10, and the crossbeam 2 is arranged between the steel guardrails 11. The rail clamping and jacking device includes a rail clamping device 15, a longitudinal hydraulic rod 16, a longitudinal hydraulic cylinder 17, a heavy-duty roller group 18, an anti-overturning electromagnetic device 19, a transverse hydraulic rod 20 and a transverse hydraulic cylinder 21.

[0072] This embodiment makes full use of the excellent mechanical properties of ultra-high performance concrete, taking a single-span assembled steel-UHPC composite beam 10 cross-line bridge as an example. By installing a jacking slide rail 8 on the jacking auxiliary platform, the slide rail 8 adopts a double I-shaped shape; the steel box beam is spliced ​​on site, the prefabricated UHPC bridge deck is installed, the wet joint is poured, the steel guardrail 11 is installed, the steel-UHPC composite beam 10 is completed, and the front guide beam is installed; the intelligent integrated jacking equipment is installed at the bottom of the steel box beam, and the intelligent integrated jacking equipment includes a rail clamping jacking device 7, an anti-overturning electromagnetic device, a slideway device, etc.; the slideway adopts a double I-shaped shape, and the intelligent integrated jacking equipment is fixed to the steel beam and cooperates with the slideway. An external prestress is set on the front guide beam, and a turning block 3 is set on the steel guardrail 11, which is anchored on the rear guide beam with multiple tensioning anchors 5; after the jacking equipment is installed, the stress state of the composite beam during the jacking process can be adjusted in real time according to the construction control calculation method in conjunction with the intelligent construction control system, so that the full-section jacking rapid construction of the steel-UHPC composite beam 10 overpass can be completed more conveniently without interrupting the traffic under the bridge, and the uninterrupted expressway 14 can be constructed.

[0073] The present invention fully considers various problems such as construction site limitations, overturning stability during jacking, and cracking of bridge decks in cantilever state during jacking. The length of the traditional guide beam is 0.65-0.85 times the length of the beam. The short guide beam used in the present invention does not exceed 0.5 times the length of the beam or the overturning stability problem is prominent during jacking construction without the guide beam; the anti-overturning electromagnetic device installed on the jacking device 7 at the bottom of the tail guide beam and the vertical limit of the double I-shaped slide rail 8 on the jacking device 7 can effectively solve the overturning problem. The multiple tensioning external prestressing can effectively control the tensile stress of the bridge deck and prevent cracking at the weak joints of the prefabricated bridge deck in the maximum cantilever state.

[0074] In this embodiment, on the basis of solving the problems of overturning stability and bridge deck cracking, the length of the guide beam is shortened or the guide beam construction is omitted, and the larger stiffness of the composite beam is relied on to solve the above problems. The multiple tensioning external prestressing can effectively control the tensile stress of the bridge deck and prevent cracking at the weak joints of the prefabricated bridge deck in the maximum cantilever state. It is also to reduce construction costs, and its prestressing arrangement is more flexible. It has lower restrictions on the construction site and is more applicable. The full-section integral jacking construction method of the simply supported steel-UHPC composite bridge without interrupting the traffic under the bridge is suitable for various application scenarios across highways and high-speed railways, and can complete the bridge construction safely, efficiently and quickly, reducing the impact on the traffic under the bridge. Compared with traditional jacking construction, local schemes can be fine-tuned according to the special construction conditions of different scenarios. It has high applicability and good economic and social benefits.

[0075] Another embodiment of the present invention provides a construction method of a full-section top-pushing construction device for a cross-line bridge:

[0076] Step 1: Build the push platform 9 and install the push rail 8;

[0077] Step 2: Assemble the channel steel beam outside the bridge site, install the front guide beam, and install the prefabricated UHPC bridge deck to form a steel-UHPC composite beam;

[0078] Step 3: Install the intelligent integrated jacking device 7 at the bottom of the steel box girder, install the external prestressing device and the steering block 3, install the crossbeam 2 on the steel guardrail 11, set up temporary support 4, and prepare for jacking;

[0079] Step 4: The jacking device 7 pushes the entire section of the steel-UHPC composite beam 10 forward, and when the front guide beam is fully pushed to the cantilever state, the external prestressing device is tensioned once, and the jacking device continues to push forward;

[0080] Step 5: When the overturning stability of the steel-UHPC composite beam 10 reaches the critical control requirement, a rear guide beam is installed at the rear end of the composite beam, and an intelligent integrated jacking device is installed at the bottom of the rear guide beam; the external prestress is tensioned for a second time, and the jacking is continued;

[0081] Step 6: After the front guide beam is pushed to the opposite bank, the external prestressing force is tensioned three times, and the deflection of the front guide beam is controlled to push it to the receiving pier or abutment on the opposite bank for shelving;

[0082] Step 7: Remove the extracorporeal prestressing measures, continue pushing, and complete the system conversion and beam drop.

[0083] When the length of the beam is insufficient due to terrain restrictions, the jacking platform 9 first pushes part of the beam end and the leading beam, and completes the production of the entire composite beam when the leading beam is pushed to a sufficient length for the subsequent beam section.

[0084] Specifically, the lower structure is constructed, the auxiliary platform for pushing is set up, and the pushing rail 8 is installed. The steel box girder is spliced ​​on site, the prefabricated UHPC bridge deck is installed, the wet joints are poured, the steel guardrail 11 is installed, the steel-UHPC composite beam 10 is completed, and the front guide beam is installed. The intelligent integrated pushing equipment is installed at the bottom of the steel box girder; the external prestressing device and the turning block 3 are installed, the crossbeam 2 is installed on the steel guardrail 11, and the temporary support 4 is set to prepare for pushing. The intelligent integrated pushing equipment realizes the full-section pushing forward of the composite beam; when the front guide beam is fully pushed to the cantilever state, the external prestress is tensioned once, and the pushing forward continues. When the overturning stability of the composite beam reaches the critical control requirements, the rear guide beam is installed at the rear end of the composite beam, and the intelligent integrated pushing equipment (including the anti-overturning electromagnetic device) is installed at the bottom of the rear guide beam; the external prestress is tensioned for a second time, and the pushing forward continues. After the front guide beam is pushed to the opposite bank, the external prestress is tensioned three times, and the deflection of the front guide beam is controlled so that it can be pushed to the receiving pier or abutment on the opposite bank for shelving. Remove the external prestressing measures, continue pushing, and complete the system conversion and beam drop. If the pushing auxiliary platform is limited by the terrain, resulting in insufficient beam length, it can be used to push part of the beam end and the front guide beam first, and then complete the production of all the composite beams after the front guide beam is pushed to a sufficient length of the subsequent beam section. Vertical jacks are arranged between the pushing auxiliary platform and the bottom of the beam to support the deadweight of the beam body to prevent the slide rail 8 device from being subjected to excessive loads. The front guide beam can adopt a short guide beam according to the site restrictions, that is, not more than 0.5 times the beam length. Its main purpose is to shorten the length of the beam; in the application scenario where a temporary bracket is set up outside the crossing road and the pushing distance is short, adding a counterweight to the rear guide beam 6 can realize the construction without the guide beam pushing. The intelligent integrated jacking equipment includes a rail clamping jacking device 7, an anti-overturning electromagnetic device, a slide device, etc.; it is symmetrically fixed at the bottom of the composite beam, and can be horizontally limited during the jacking process of the composite beam without the need to arrange a correction device. The jacking slide rail 8 adopts a double I-shaped design. The intelligent integrated jacking equipment cooperates with the slide rail 8 through a heavy-loaded roller group to limit the vertical displacement of the composite beam as an anti-overturning safety reserve during the jacking process. The working process of a single rail clamping jacking device 7 includes: the horizontal hydraulic cylinder pushes out the hydraulic rod to apply a preload force between the heavy-loaded roller group of the integrated jacking equipment and the slide rail 8; the vertical hydraulic cylinder pushes out the hydraulic rod to push the slide device fixed at the bottom of the beam forward; the horizontal hydraulic cylinder retracts to eliminate the preload force; the vertical hydraulic cylinder retracts to drive the rail clamping jacking device to return to its initial state; repeat this step to achieve jacking work. Multiple jacking devices need to realize synchronous multi-point jacking work through an intelligent construction control system. The rear guide beam can use a counterweight beam as needed to reduce the load of the anti-overturning device. Its maximum counterweight should not exceed 1 / 10 of the weight of the composite beam. The anti-overturning electromagnetic device only needs to be installed on the jacking equipment under the rear guide beam. Its maximum rated suction force is designed according to the anti-overturning requirements required for the maximum cantilever state of the composite beam jacking; its maximum pull-off force is designed to meet 1.5-2 times the maximum rated suction force. Since the bridge professional finite element software Midas civil can only analyze the stage and magnitude of the negative reaction force of the bearing.Therefore, the present invention proposes a corresponding calculation method for the design calculation of the required maximum rated suction force and the control calculation during the jacking process.

[0085] Another embodiment of the present invention provides a control calculation method for a full-section jacking construction device for a cross-line bridge, comprising:

[0086] Step 1: Calculate the stage when the cantilever state overturns during the composite beam jacking process, assuming that in the critical state of overturning, except for the outermost support under compression, the other supports are empty;

[0087] Step 2: Perform force analysis according to the analytical method. To simplify the force analysis, the overturning stability coefficient is used as the boundary and divided into two stages. In one stage, the overturning stability coefficient is less than the specified requirement. At this time, the top-pushing process begins to have the risk of overturning. In the other stage, the overturning stability coefficient is the smallest. At this time, the overturning risk of the top-pushing process is the greatest.

[0088] Step 3: The control value of the magnetic attraction force F corresponding to any cantilever length x of the top-pushing main beam from the time when there is a risk of overturning during the top-pushing process to the time when the risk of overturning during the top-pushing process is the maximum is:

[0089]

[0090] The weight and stiffness of the guide beam and the main beam are evenly distributed, K is the required overturning stability coefficient, and the length, weight and stiffness of the main beam are L, q respectively. z 、E z I z , the guide beam weight and stiffness are L d ,q d 、E d I d , the length, weight and stiffness of the counterweight beam are respectively; L p ,q p 、E p I p ;

[0091] Step 4: According to the two stages divided in step 2, the corresponding magnetic attraction control values ​​F1 and F2 are calculated, and the magnetic attraction control values ​​are calculated according to the envelope classification.

[0092] The control value of the overturning stability coefficient is usually taken as 1.5 to ensure that the composite beam will not overturn. Referring to the other calculation steps, the control value of the magnetic attraction F of the anti-overturning electromagnetic device at each stage is obtained. The control value of the magnetic attraction can be designed according to the envelope classification to reduce the adjustment of the magnetic attraction of the anti-overturning electromagnetic device during the construction process; the intelligent construction control system can also be used for dynamic adjustment, and the design value of the maximum rated suction of the anti-overturning electromagnetic device is 1.5 times the required maximum control value. The external prestressing adopts multiple tensioning anchors 5, which are anchored to the front guide beam and the rear guide beam respectively; the crossbeam 2 and temporary support 4 are set on the steel guardrail 11, and the steering block 3 is installed to correct the tensioning angle of the prestressed steel strands, improve the efficiency of prestressing, and avoid the risk of cracking caused by excessive tensile stress of the UHPC bridge deck in the cantilever state of the composite beam with bridge deck;

[0093] The external prestressing tensile stress δ e The control value should satisfy the following formula:

[0094]

[0095] In the formula, L, q z 、E z I z are the length, weight and stiffness of the main beam respectively; L d ,q d 、E d I d are the guide beam weight and stiffness respectively; A e ,δ e are the cross-sectional area and tensile stress control value of the external prestressed steel strand 1; δ max is the maximum tensile stress of the UHPC bridge deck; [δ] is the design value of the tensile stress strength of the UHPC bridge deck; α is the angle between the external prestressed steel strand 1 and the horizontal direction.

[0096] According to experimental research, under the action of negative bending moment, the nominal initial crack stress of the cast-in-place UHPC bridge deck (excluding joints) is about 14MPa, and the nominal initial crack stress of the prefabricated UHPC board (rectangular joints) is about 11MPa, while the nominal stress corresponding to a 0.05mm crack reaches 18-26MPa.

[0097] Bridge deck form Nominal initial crack stress / MPa 0.05mm crack nominal stress / MPa Cast-in-place ordinary concrete 3.23 5.43 Cast-in-place UHPC panels 14.25 26.09 Prefabricated UHPC panels (rectangular joints) 11.02 18.13 Prefabricated UHPC panels (T-joints) 12.23 21.3

[0098] For simply supported steel-UHPC composite cross-line bridges, if prefabricated UHPC bridge decks are used for construction, the cracking of the joints should be paid attention to, and joints with better crack resistance or dense reinforcement can be used. Since the UHPC bridge deck with a crack of 0.05mm will not affect its durability, and the whole bridge is subjected to positive bending moment after the jacking of the simply supported steel-UHPC composite cross-line bridge, the stress of the bridge deck in the cantilever state does not exceed 0.75 times the nominal stress of the 0.05mm crack, prestressing can also be omitted.

[0099] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0100] The present invention is an improvement and innovation of the walking-type jacking process and the dragging-type jacking process to adapt to the application scenario of the full-section integral jacking construction of a single-span steel-UHPC composite bridge without interrupting the traffic under the bridge. Compared with the walking-type jacking process, its advantage is that it inherits the characteristic of not generating excessive horizontal thrust on the beam body during the jacking process, and through the consolidation of the jacking device 7 and the beam body, the repeated jacking and lowering process is eliminated to reduce the risk of overturning during the jacking process; compared with the dragging-type jacking process, its advantage is that the single-point jacking or single-point traction in the dragging-type jacking process is eliminated, and the large horizontal thrust generated on the beam body during the jacking process is evenly distributed in the beam body by using a multi-point synchronous jacking system.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A full-section jacking construction device for a cross-line bridge, characterized in that: include: A jacking platform, wherein the jacking platform is arranged on the newly built roadbed; A slide rail, wherein the slide rail is arranged on the push platform; A pushing device, wherein the pushing device is arranged on the slide rail; Front and rear guide beams, the front and rear guide beams are arranged on the jacking device; Multiple tensioning anchors, the multiple tensioning anchors are arranged on the front and rear guide beams; An external prestressed steel strand, wherein the external prestressed steel strand is connected to a multiple tensioning anchor; A steering block connected to an external prestressed steel strand; A support, the support being arranged at the lower end of the steering block; A crossbeam is connected to the support.

2. The full-section top-pushing construction device for a cross-line bridge according to claim 1, characterized in that: It also includes steel guardrails and steel-UHPC composite beams, and cross beams are arranged between the steel guardrails.

3. The full-section top-pushing construction device for a cross-line bridge according to claim 2, characterized in that: The pushing device adopts an intelligent integrated pushing device, which includes a rail clamping pushing device, an anti-overturning electromagnetic device and a slide device. The intelligent integrated pushing device is symmetrically fixed to the bottom of the steel-UHPC composite beam and performs lateral limitation during the pushing process of the composite beam.

4. The full-section jacking construction device for a cross-line bridge as claimed in claim 3 is characterized in that: The slide rail adopts a double I-shaped structure, and the intelligent integrated pushing device cooperates with the slide rail through a heavy-load roller group and limits the vertical displacement of the steel-UHPC composite beam to serve as an anti-overturning safety reserve during the pushing process.

5. The full-section jacking construction device for a cross-line bridge according to claim 1, characterized in that: A vertical jack is arranged between the jacking platform and the bottom of the beam to support the deadweight of the beam body, and the front guide beam adopts a short guide beam according to the site restrictions.

6. A method for pushing the full section of a cross-line bridge forward, based on the full section pushing construction device for a cross-line bridge forward according to claims 1-5, characterized in that: The following steps are involved: Step 1: Build the push platform and install the push rail; Step 2: Assemble the channel steel beam outside the bridge site, install the front guide beam, and install the prefabricated UHPC bridge deck to form a steel-UHPC composite beam; Step 3: Install the intelligent integrated jacking device at the bottom of the steel box girder, install the external prestressing device and the turning block, install the crossbeam on the steel guardrail, set up temporary support, and prepare for jacking; Step 4: The jacking device pushes the entire section of the steel-UHPC composite beam forward, and when the front guide beam is fully pushed to the cantilever state, the external prestressing device is tensioned once and continues to be pushed forward; Step 5: When the overturning stability of the steel-UHPC composite beam reaches the critical control requirements, install the rear guide beam at the rear end of the composite beam, and install the intelligent integrated jacking equipment at the bottom of the rear guide beam; tension the external prestress for the second time, and continue to push forward; Step 6: After the front guide beam is pushed to the opposite bank, the external prestressing force is tensioned three times, and the deflection of the front guide beam is controlled to push it to the receiving pier or abutment on the opposite bank for shelving; Step 7: Remove the extracorporeal prestressing measures, continue pushing, and complete the system conversion and beam drop.

7. The full-section top-pushing construction method for a cross-line bridge according to claim 6, characterized in that: When the length of the beam is insufficient due to terrain restrictions, the pushing platform first pushes part of the beam ends and the leading beam, and completes the production of the entire composite beam when the leading beam is pushed to a sufficient length for the subsequent beam section.

8. The full-section top-pushing construction method for a cross-line bridge according to claim 6, characterized in that: The external prestressing adopts multiple tensioning anchors, which are anchored to the front guide beam and the rear guide beam respectively; cross beams and temporary supports are set on the steel guardrails, and turning blocks are installed to correct the tensioning angle of the prestressed steel strands, improve the efficiency of prestressing, and avoid the risk of cracking caused by excessive tensile stress of the UHPC bridge deck in the cantilever state of the composite beam with bridge deck; External prestressing tensile stress δ e The control value should satisfy the following formula: In the formula, L, q z 、E z I z are the length, weight and stiffness of the main beam respectively; L d ,q d 、E d I d are the guide beam weight and stiffness respectively; A e , δ e are the cross-sectional area of ​​the external prestressed steel strand and the control value of the tension stress; δ max is the maximum tensile stress of UHPC bridge deck; [δ] is the design value of tensile stress strength of UHPC bridge deck; α is the angle between the external prestressed steel tendon and the horizontal direction.

9. A control calculation method for a full-section jacking construction device for a cross-line bridge, based on the full-section jacking construction method for a cross-line bridge according to any one of claims 6 to 8, characterized in that: include: Step 1: Calculate the stage when the cantilever state overturns during the composite beam jacking process, assuming that in the critical state of overturning, except for the outermost support under compression, the other supports are empty; Step 2: Perform force analysis according to the analytical method. To simplify the force analysis, the overturning stability coefficient is used as the boundary and divided into two stages. In one stage, the overturning stability coefficient is less than the specified requirement. At this time, the top-pushing process begins to have the risk of overturning. In the other stage, the overturning stability coefficient is the smallest. At this time, the overturning risk of the top-pushing process is the greatest. Step 3: The control value of the magnetic attraction force F corresponding to any cantilever length x of the top-pushing main beam from the time when there is a risk of overturning during the top-pushing process to the time when the risk of overturning during the top-pushing process is the maximum is: The weight and stiffness of the guide beam and the main beam are evenly distributed, K is the required overturning stability coefficient, and the length, weight and stiffness of the main beam are L, q respectively. z 、E z I z , the guide beam weight and stiffness are L d ,q d 、E d I d , the length, weight and stiffness of the counterweight beam are respectively; L p ,q p 、E p I p ; Step 4: According to the two stages divided in step 2, the corresponding magnetic attraction control values ​​F1 and F2 are calculated, and the magnetic attraction control values ​​are calculated according to the envelope classification.

10. The control calculation method for the full-section top-pushing construction device of the overpass bridge according to claim 9 is characterized in that: The control value of the overturning stability coefficient is usually taken as 1.5 to ensure that the composite beam will not overturn. Referring to the other calculation steps, the control value of the magnetic attraction force F of the anti-overturning electromagnetic device at each stage is obtained, and the magnetic attraction control value is designed according to the envelope classification to reduce the adjustment of the magnetic attraction force of the anti-overturning electromagnetic device during the construction process; the intelligent construction control system is used for dynamic adjustment, and the design value of the maximum rated suction force of the anti-overturning electromagnetic device is 1.5 times the required maximum control value.

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