Distributed self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge and method

Abstract

The present application relates to a decentralized self-anchored central main cable steel truss cable-stayed suspension cooperative system bridge and method, comprising: a tower-beam body, the tower-beam body comprising at least two bridge towers spaced apart along the longitudinal direction of the bridge, the crossbeams of the two bridge towers supporting a steel truss main beam, the steel truss main beam comprising a main span beam section located in the main span and a side span beam section located in the side span; a cable-stayed system comprising a double-cable-plane cable-stayed system, the upper ends of the double-cable-plane cable-stayed systems being anchored to the bridge towers, and the lower ends of the double-cable-plane cable-stayed systems being anchored to both sides of the steel truss main beam; a suspension cable system comprising a central main cable supported on the top of the bridge tower and a plurality of suspension cables suspending the central position of the main span beam section, the central main cable gradually separating from the tower top toward the side span direction and then dispersedly anchored in the central position of the side span beam section. The present application avoids the problems of conventional cooperative system bridges using two different sets of construction methods and equipment, resulting in relatively high construction costs and difficulty in merging the cable-stayed area and the suspension cable area.

Description

Technical Field

[0001] The present application relates to the technical field of cable-supported bridges, and in particular to a decentralized self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge and method. Background Art

[0002] Cable-supported bridges use main cables, stay cables, and other wires as their primary load-bearing components. They are particularly suitable for the construction of long-span dual-use highway and railway bridges. Common cable-supported bridges include cable-stayed bridges and suspension bridges. Cable-stayed bridges offer the advantage of greater structural rigidity. However, as spans increase, the large dead and live loads on dual-use highway and railway bridges lead to excessive length and weight of the mid-span stay cables, and the axial pressure on the main beam at the bridge towers is enormous, limiting their main spans to approximately 1,300 meters. Compared to cable-stayed bridges, the main beams of suspension bridges do not bear pressure, and the main cables are manufactured using a holistic approach, resulting in greater span capacity. However, their rigidity is relatively low, making it difficult to meet the rigidity requirements of large bridges for railway operation.

[0003] In recent years, cable-stayed and suspension-type bridges have been proposed for the construction of long-span dual-use cable-supported bridges for both road and rail use. While these bridges combine the high structural rigidity of cable-stayed bridges with the strong spanning capacity of suspension bridges, their application still presents several technical challenges that warrant further investigation:

[0004] (1) The cable-stayed area near the tower of the collaborative system bridge adopts the same cantilever erection scheme as the cable-stayed bridge, that is, the bridge crane is used to lift the bridge, and the cantilevered beam sections are rigidly connected from the bridge tower to the mid-span and the beam ends. The cable-stayed area in the mid-span adopts the same erection scheme as the suspension bridge, that is, the cable-mounted crane is used to lift the bridge, and the beam sections are first hinged and then rigidly connected from the mid-span to the bridge tower. In other words, the erection of the collaborative system bridge requires two different sets of construction methods and equipment, which is relatively costly and there is mutual interference. In addition, the location and timing of the joints in the cable-stayed and cable-stayed areas are difficult to determine or the conditions are relatively strict.

[0005] (2) In order to achieve a smooth transition of the structural stiffness between the cable-stayed and suspension zones and ensure that the fatigue stress of the bridge components, especially the highway-railway dual-use bridge components, meets the requirements of the specifications, a long cable-stayed and suspension transition zone needs to be set up in the longitudinal direction. In order to avoid mutual interference between the cable-stayed and suspension cables in the transition zone, the steel truss bridge often needs to adopt a longitudinal and transverse staggered anchoring scheme: the cable-stayed and suspension cables are arranged longitudinally at different main truss nodes with longitudinal staggering, while the cable-stayed cables are anchored to the upper chord and the suspension cables are anchored to the outer brackets of the upper chord with transverse staggering. The above scheme has relatively complex cable-stayed and suspension cable arrangements and anchor point structures. Although it can avoid mutual interference between the cable-stayed and suspension cable anchor points, there is still a risk of collision when the cable-stayed and suspension cables vibrate due to wind and rain.

[0006] (3) Although the anchorage of the cooperative system bridge is smaller than that of the suspension bridge, the cost of anchorage may still be high or there may be no conditions for setting it up under some conditions with limited terrain and geological conditions. In recent years, although some scholars have proposed a self-anchored suspension-cable-stayed cooperative system bridge, that is, the main span uses steel beams to reduce its own weight and the side span concrete beams anchor the main cables, the relevant schemes have not yet solved the above (1) and (2) problems, and have brought about the following new problems: First, the stress at the steel-concrete joint is relatively complex and difficult to meet the stress requirements of the road-rail dual-use bridge; second, the main cable force is large, and the concentrated anchoring at the end of the concrete beam leads to high local compressive stress in the concrete; third, the scheme of anchoring the main beam with the side span concrete beam is acceptable when applied to the box beam scheme, but when applied to the truss beam, the side span concrete beam structure is difficult to connect with the steel truss beam, the steel-concrete joint structure is complex, and the force transmission path is unclear. Summary of the Invention

[0007] The embodiments of the present application provide a decentralized self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge and method to solve the problems in related technologies that the cooperative system bridge adopts two sets of different construction methods and equipment, the construction cost is relatively high, the cable-stayed area and the suspension area are difficult to connect, the cable-stayed cables and suspension cables in the transition area interfere with each other, and anchors are still required, or the existing self-anchored suspension-cable-stayed cooperative system bridge solution cannot be applied to large-span dual-purpose road-rail steel truss cooperative body bridges.

[0008] A first aspect of an embodiment of the present application provides a decentralized self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge, comprising:

[0009] A tower-beam body, the tower-beam body comprising at least two bridge towers spaced apart along the longitudinal direction of the bridge, the cross beams of the two bridge towers supporting a steel truss main beam, the steel truss main beam comprising a main span beam section located in the main span and a side span beam section located in the side span;

[0010] A stay cable system, comprising double-cable-plane stay cables, the upper ends of which are anchored to the bridge towers, and the lower ends of which are anchored to both sides of the steel truss main beams;

[0011] The suspension cable system includes a central main cable supported on the top of the bridge tower and multiple suspension cables suspending the central position of the main span beam section. The central main cable gradually separates from the tower top to the side span direction and is then dispersedly anchored in the central position of the side span beam section.

[0012] In some embodiments, the main span beam section includes a cooperation zone beam section located in the middle of the span, and a cable-stayed zone beam section located at both ends of the cooperation zone beam section, and the double-cable-plane cable-stayed cable covers and connects the cable-stayed zone beam section and the cooperation zone beam section;

[0013] The upper end of the sling is connected to the central main cable, and the lower end of the sling is anchored at the central position of the collaborative area beam section. The double-cable-plane inclined cable and the sling connecting the collaborative area beam section jointly bear the dead load and live load of the collaborative area beam section.

[0014] In some embodiments: the bridge tower includes, from top to bottom, a single-column upper tower column, a middle tower column with a double-limb cross-section, and a lower tower column that gradually tilts inward from top to bottom, and the crossbeam is connected to the connection position between the middle tower column and the lower tower column.

[0015] In some embodiments: the cross-section of the upper tower column is polygonal, the upper end of the double-cable-plane inclined cable is anchored to the upper tower column, the central main cable is supported on the top of the upper tower column through the main cable saddle, and turns from the top of the upper tower column toward the main span and the side span.

[0016] In some embodiments: the central main cable is composed of multiple parallel steel wire strands or multiple finished strands of sealed steel wire ropes, the central main cable located on the main span side is connected into a whole by a main cable clamp, the upper end of the sling is connected to the main cable clamp, and the top of the bridge tower is provided with a main cable saddle supporting the central main cable.

[0017] In some embodiments: the steel truss main beam includes an upper bridge deck and a lower bridge deck, the upper chords on both sides of the upper bridge deck are provided with anchor plates connected to the lower ends of the double-cable-plane inclined cables, the central isolation belt of the upper bridge deck is provided with connecting ear plates connected to the lower ends of the suspension cables, and anchor plates connected to the ends of the central main cables.

[0018] In some embodiments: the upper bridge deck is paved with an upper highway lane, the central position of the lower bridge deck is paved with a railway track, the lower bridge deck is paved with lower highway lanes on both sides of the railway track, and a separation zone is provided between the lower highway lanes and the railway track.

[0019] In some embodiments: the tower beam body includes side piers and auxiliary piers located on the side of the side span for supporting the side span beam section, and the side piers and auxiliary piers support the side span beam section through vertical supports and transverse supports respectively.

[0020] A second aspect of the present application provides a construction method for a decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system. The method uses the decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system described in any of the above embodiments. The method comprises:

[0021] Construct the bridge tower bottom foundation, bridge tower, side piers and auxiliary piers at the set location;

[0022] Cantilever the steel truss main beam segments on the bridge towers one by one and install the double-cable-plane inclined cables. Perform preliminary adjustment of the cable tension of the double-cable-plane inclined cables until the steel truss main beam is connected.

[0023] The central main cables are installed one by one using the closed steel truss main beam as a construction platform. The central main cables are supported on the top of the bridge tower and gradually spread out from the tower top towards the side spans before being dispersed and anchored in the center of the side span beam section.

[0024] A main cable clamp is installed on the main span side of the central main cable, and multiple slings for suspending the main span beam section are installed on the main cable clamp. The lower ends of the slings are tensioned and anchored in the center of the main span beam section.

[0025] The second phase of constant load is constructed on the steel truss main beam, and the tension of the double-sided inclined cables and the tension of the suspenders are adjusted synchronously to change the linear shape of the steel truss main beam to the completed bridge state.

[0026] A third aspect of the present application provides a method for determining cable forces in a decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system. The method uses the decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system described in any of the above embodiments, and the method includes:

[0027] Model the double-cable-plane cable-stayed bridge and determine the dead load force T of the i-th cable ih And the maximum cable force T of dead load + live load imax ;

[0028] Establish the maximum cable force limit of the entire bridge [T max ], filter the maximum cable force T of the i-th inclined cable in the mid-span area imax Exceeding the maximum cable force limit [T max ] and serves as the cable-stayed cable cooperation area;

[0029] The proportion of the main beam dead load shared by the i-th inclined cable within the cable force limit is set to w ,0< w <1, estimate the maximum cable force T' of the dead load + live load of the i-th inclined cable imax ;

[0030] Determine whether T' is satisfied imax ≤[T max ], if not, iteratively adjust w Until T' imax ≤[T max ], if you go to the next step;

[0031] According to the proportion of the main beam dead load shared by the i-th inclined cable w , determine the ratio of the main beam dead load shared by the central main cable and the sling to be 1- w ;

[0032] According to the ratio of the main beam dead load shared by the central main cable and the sling 1- w Determine the specifications of the slings and determine the cable force and specifications of the central main cable based on the main span-to-main cable ratio;

[0033] Determine the number of distributed anchorage points for the central main cable in the side span based on the central main cable force and the maximum central single-point main cable anchorage force of the side span beam section;

[0034] The established double-cable-plane cable-stayed bridge model was adjusted to obtain a distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge;

[0035] Analyze whether the maximum cable force of the inclined cable, the central main cable and the sling tension meet the expected requirements. If not, return to the corresponding position and make appropriate adjustments to the relevant parameters until the expected requirements are met.

[0036] The beneficial effects of the technical solution provided by this application include:

[0037] An embodiment of the present application provides a distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge and method. Since the tower-beam body of the distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge of the present application includes at least two bridge towers spaced apart along the bridge direction, the crossbeams of the two bridge towers support a steel truss main beam, and the steel truss main beam includes a main span beam section located in the main span and a side span beam section located in the side span; a cable-stayed system, which includes a double-cable-plane cable-stayed cable, the upper end of the double-cable-plane cable-stayed cable is anchored to the bridge tower, and the lower end of the double-cable-plane cable is anchored to both sides of the steel truss main beam; a suspension cable system, which includes a central main cable supported on the top of the bridge tower and a plurality of suspension cables suspended in the central position of the main span beam section, the central main cable gradually separates from the tower top to the side span direction and is dispersedly anchored in the central position of the side span beam section.

[0038] Therefore, the decentralized self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge of the present application is mainly subjected to stress by the cable-stayed system, and supplemented by the suspension cable system using the central main cable and suspension cables to bear part of the dead load and live load. While ensuring that the maximum cable force of the cable-stayed cable is controlled within the limit for easy manufacturing and installation, the advantages of the high structural rigidity of the steel truss main girder and cable-stayed system bridge are maximized. The cable-stayed cable system covers the entire main span beam section, and the main girder can be cantilevered until it is connected. Subsequently, the through steel truss main girder is used as a construction platform to construct the decentralized self-anchored central main cable and its suspension cables. The steel truss main girder construction method of the present invention is basically the same as that of the cable-stayed bridge, avoiding the problems of conventional coordinated system bridges using two different sets of construction methods and equipment, resulting in relatively high construction costs, and difficulty in connecting the cable-stayed area and the suspension area.

[0039] In addition, the upper ends of the double-cable-plane stay cables of the distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge of the present application are anchored to the bridge tower, and the lower ends of the double-cable-plane stay cables are anchored to both sides of the steel truss main beam; the distributed self-anchored central main cable and its slings are located at the central dividing strip of the steel truss main beam. The lower end of the sling is hinged to the central position of the main span beam section, and the upper end of the sling is connected to the central main cable through a main cable clamp. The central main cable is supported on the top of the bridge tower, and the two ends of the central main cable are respectively anchored to the anchor plates in the central position of the side span beam section. The lateral spatial positions of the double-cable-plane stay cables and the distributed self-anchored central main cable and its slings are completely staggered, which can effectively avoid the problem of mutual interference between the stay cables and slings within the cable-stayed-suspension cooperative area. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0041] Figure 1 This is a schematic elevational structural diagram of a cable-stayed and suspension-coordinated bridge with a decentralized self-anchored central main cable steel truss system according to an embodiment of the present application;

[0042] Figure 2 This is a schematic diagram of the transverse structure of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0043] Figure 3 This is a schematic diagram of the tower structure of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0044] Figure 4 This is a structural schematic diagram of step 101 of a construction method for a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0045] Figure 5 This is a structural diagram of step 102 of the construction method of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0046] Figure 6 This is a structural diagram of step 103 of the construction method of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0047] Figure 7 This is a structural diagram of step 104 of the construction method of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0048] Figure 8 This is a structural diagram of step 105 of the construction method of a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated system bridge according to an embodiment of the present application;

[0049] Figure 9 Flowchart of a method for determining cable forces in a distributed self-anchored central main cable steel truss cable-stayed-suspension coordinated system bridge according to an embodiment of the present application.

[0050] Reference numerals:

[0051] 1. Bridge tower; 2. Steel truss main beam; 3. Double-cable-plane stay cable; 4. Central main cable; 5. Suspension cable; 6. Auxiliary pier; 7. Side pier; 8. Main cable clamp; 11. Upper tower column; 12. Middle tower column; 13. Lower tower column; 14. Crossbeam; 21. Upper bridge deck; 22. Lower bridge deck; 23. Anchor plate; 24. Isolation strip; 25. Upper highway lane; 26. Railway track; 27. Lower highway lane. DETAILED DESCRIPTION

[0052] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0053] The embodiments of the present application provide a decentralized self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge and method, which can solve the problems in related technologies that the cooperative system bridge adopts two sets of different construction methods and equipment, the construction cost is relatively high, the cable-stayed area and the suspension area are difficult to connect, the cable-stayed cables and suspension cables in the transition area interfere with each other, and anchors still need to be set up, or the existing self-anchored suspension-cable-stayed cooperative system bridge scheme cannot be applied to large-span dual-purpose road-rail steel truss cooperative body bridges.

[0054] See also Figure 1 and Figure 2 As shown, the first aspect of the embodiment of the present application provides a decentralized self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge, comprising:

[0055] The tower-girder body comprises at least two spaced-apart towers 1 along the length of the bridge. The distance between the two towers 1 determines the main span, and the two towers 1 have identical structures. The crossbeams 14 of the two towers 1 support a steel truss main girder 2. The steel truss main girder 2 includes a main span section located between the two towers 1 and a side span section located in the side spans.

[0056] The cable system includes double-plane cables 3, the upper ends of which are anchored to the bridge tower 1, and the lower ends of which are anchored to both sides of the steel truss girder 2. The double-plane cables 3 are composed of several cables that together diagonally pull the steel truss girder 2 to the bridge tower 1. Some of the cables are anchored to the left side of the steel truss girder 2 to form the left cable plane, and the other part is anchored to the right side of the steel truss girder 2 to form the right cable plane.

[0057] The suspension cable system includes a central main cable 4 connected to the top of the bridge tower 1 and multiple suspension cables 5 suspending the center of the main span beam section. The central main cable 4 gradually spreads out from the tower top toward the side spans and is then anchored in the center of the side span beam sections. The horizontal projection of the central main cable 4 and the multiple suspension cables 5 suspending the center of the main span beam section on the steel truss main girder 2 is located at the center axis of the steel truss main girder 2, that is, at the center.

[0058] The decentralized self-anchored central main cable steel truss girder cable-stayed-suspension cooperative system bridge of the embodiment of the present application is mainly subjected to stress by the cable-stayed system, and supplemented by the suspension cable system using the central main cable 4 and the sling 5 to bear part of the dead load and live load. While ensuring that the maximum cable force of the cable-stayed cable is controlled within the limit for manufacturing and installation, the advantages of the high structural rigidity of the steel truss main girder 2 and the cable-stayed system are maximized.

[0059] The cable-stayed system covers the entire main span, allowing the steel truss main girder 2 to be cantilevered until it is closed. The through-girder 2 can then be used as a construction platform for the installation of the decentralized, self-anchored central main cables 4 and their slings 5. The construction method for the steel truss main girder 2 in this invention is essentially the same as that used in cable-stayed bridges, avoiding the relatively high construction costs and difficulty in closing the cable-stayed and cable-stayed sections that are associated with conventional coordinated system bridges, which rely on two different construction methods and equipment.

[0060] In the embodiment of the present application, the upper ends of the double-plane stay cables 3 of the distributed self-anchored central main cable steel truss girder cable-stayed and suspension system bridge are anchored to the bridge tower 1, and the lower ends of the double-plane stay cables 3 are anchored to either side of the steel truss girder 2. The distributed self-anchored central main cable 4 and its slings 5 ​​are located in the central dividing strip of the steel truss girder 2. The lower ends of the slings 5 ​​are hinged to the center of the main span beam 2, and the upper ends of the slings 5 ​​are connected to the central main cable 4 via main cable clamps 8.

[0061] The central main cable 4 is supported at the top of the bridge tower 1, with its ends anchored to anchor plates in the center of the side span beams. The dual-plane stay cables 3 and the decentralized, self-anchored central main cables 4 and their slings 5 ​​are completely staggered in transverse space, effectively preventing interference between the stay cables and slings within the coordinated stay-cable-cable area.

[0062] The central main cable 4 and its slings 5 ​​of the distributed self-anchored central main cable steel truss cable-stayed and suspension bridge system of this embodiment bear less dead and live loads than conventional self-anchored coordinated systems, resulting in less stress on the central main cable 4. The central main cable 4 is composed of multiple strands of parallel steel wire or sealed steel wire rope, with both ends anchored to anchor plates in the center of the side span beams. This reduces stress, facilitates manufacturing and installation, and features a simple anchoring structure and well-defined stress distribution.

[0063] In some alternative embodiments: See Figure 1 and Figure 2 As shown, the present invention provides a decentralized, self-anchored, central main cable steel truss girder cable-stayed and suspension-cable coordinated bridge system. The main span of this steel truss girder coordinated bridge system includes a coordinated zone girder section located in the middle of the span and cable-stayed zone girder sections located at both ends of the coordinated zone girder section. The coordinated zone girder section is connected to the bridge tower 1 via inclined cables and to the central main cable 4 via suspension cables 5. The cable-stayed zone girder section is connected to the bridge tower 1 solely via inclined cables.

[0064] The double-cable-plane stay cables 3 cover and connect the cable-stayed and collaborative-area beam sections. This means both the cable-stayed and collaborative-area beam sections must be connected to the bridge tower 1 via the double-cable-plane stay cables 3. The main span beam sections in this application do not include the suspension-area beam sections. The upper ends of the sling cables 5 are connected to the central main cables 4, and the lower ends of the sling cables 5 are anchored in the center of the collaborative-area beam section. The double-cable-plane stay cables 3 and the sling cables 5 connecting the collaborative-area beam section jointly bear the dead and live loads of the collaborative-area beam section.

[0065] In some alternative embodiments: See Figure 1 and Figure 3 As shown, the embodiment of the present application provides a decentralized self-anchored central main cable steel truss cable-stayed and suspension bridge system. The bridge tower 1 of the steel truss bridge system includes, from top to bottom, a single-column upper tower column 11, a double-branch cross-section middle tower column 12, and a lower tower column 13 that gradually tilts inward from top to bottom. A crossbeam 14 is connected to the connection between the middle tower column 12 and the lower tower column 14.

[0066] The upper tower 11 has a polygonal cross-section. The upper ends of the double-plane stay cables 3 are anchored to the upper tower 11. The central main cable 4 is supported at the top of the upper tower 11 via a main cable saddle and deflected from the top toward the main span and side spans. The central main cable 4 is composed of multiple parallel steel wire strands or finished strands of multiple sealed steel wire ropes. The central main cable 4 on the main span side is connected to the main cable clamp 8, to which the upper ends of the slings 5 ​​are attached.

[0067] In some alternative embodiments: See Figure 2As shown, an embodiment of the present application provides a decentralized self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge. The steel truss girder 2 of the steel truss coordinated system bridge includes an upper deck 21 and a lower deck 22. The upper chords on both sides of the upper deck 21 are equipped with anchor plates 23 connected to the lower ends of the double-cable-plane stay cables 3. The central isolation strip of the upper deck 21 is equipped with a connecting lug connecting the lower ends of the suspension cables 5 and an anchor plate connected to the end of the central main cable 4.

[0068] The upper deck 21 is paved with an upper highway lane 25, which is a highway lane. A bidirectional high-speed railway track 26 is paved in the center of the lower deck 22. Lower highway lanes 27 are paved on both sides of the lower deck 22, which are ordinary highway lanes. A median strip 24 is provided between the lower highway lanes 27 and the railway track 26 to protect the railway track 26.

[0069] In some alternative embodiments: See Figure 2 As shown, an embodiment of the present application provides a distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge, the tower beam body of the steel truss cooperative system bridge includes a side pier 7 and an auxiliary pier 6 for supporting the side span beam section on the side span side, and the side pier 6 and the auxiliary pier 7 support the side span beam section through vertical supports and transverse supports respectively.

[0070] See also Figures 4 to 8 As shown, a second aspect of the embodiments of the present application provides a construction method for a decentralized self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge, the method using the decentralized self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge described in any of the above embodiments, the method comprising:

[0071] Step 101 : constructing the bridge tower bottom foundation, the bridge tower 1 , the side pier 7 and the auxiliary pier 6 at the set position.

[0072] Step 102 , cantilevering the steel truss main beam 2 segments on the bridge tower 1 one by one and installing the double-cable-plane inclined cables 3 , and initially adjusting the cable forces of the double-cable-plane inclined cables 3 until the steel truss main beam 2 is connected.

[0073] Step 103: Use the joined steel truss main beam 2 as a construction platform to install the central main cable 4 one by one. The central main cable 4 is supported on the top of the bridge tower 1 and gradually separates from the tower top toward the side span and is then dispersedly anchored at the center of the side span beam section.

[0074] Step 104: Install a main cable clamp 8 on the main span side of the central main cable 4, install multiple slings 5 ​​for suspending the main span beam section on the main cable clamp 8, and anchor the lower ends of the slings 5 ​​at the center of the main span beam section after tensioning.

[0075] Step 105 , construct the second phase of constant load on the steel truss main beam 2 , and synchronously adjust the cable forces of the double-cable-plane inclined cables 3 and the slings 5 ​​to change the linear shape of the steel truss main beam 1 to the completed bridge state.

[0076] See also Figure 9 As shown, a third aspect of the embodiments of the present application provides a method for determining cable forces in a decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system. The method uses the decentralized self-anchored central main cable steel truss girder cable-stayed and cable-suspension coordinated bridge system described in any of the above embodiments, and the method includes:

[0077] S101: Model a double-cable-plane cable-stayed bridge and determine the dead load force T of the i-th cable. ih And the maximum cable force T of dead load + live load imax .

[0078] S102, establish the maximum cable force limit for the entire bridge [T max ], filter the maximum cable force T of the i-th inclined cable in the mid-span area imax Exceeding the maximum cable force limit [T max ] range and serve as the cable-stayed cable cooperation area.

[0079] S103: Set the proportion of the main beam dead load shared by the i-th inclined cable within the cable force limit range to w ,0< w <1, estimate the maximum cable force T' of the dead load + live load of the i-th inclined cable imax .

[0080] S104, determine whether T' is satisfied imax ≤[T max ], if not, return to step S102 for iterative adjustment w Until T' imax ≤[T max ], if so, proceed to the next step S105.

[0081] S105, based on the proportion of the main beam dead load shared by the i-th inclined cable w , determine that the ratio of the main beam dead load shared by the central main cable 4 and the sling 5 is 1- w .

[0082] S106, according to the ratio of the main beam dead load shared by the central main cable 4 and the sling 5 1- w Determine the specifications of the sling 5, and determine the cable force and specifications of the central main cable 4 based on the main span ratio of the main cable.

[0083] S107 , determining the number of distributed anchoring points of the central main cable 4 in the side span according to the cable force of the central main cable 4 and the maximum main cable anchoring force at a central single point of the side span beam section.

[0084] S108, adjusting the established double-cable-plane cable-stayed bridge model to obtain a distributed self-anchored central main cable steel truss girder cable-stayed-suspension cooperative system bridge.

[0085] S109, analyzing whether the tension of the central main cable 4 and the sling 5 meets the expected requirements. If not, return to step S106 to make appropriate adjustments to the relevant parameters until the expected requirements are met; if so, proceed to the next step S110.

[0086] S110, analyzing whether the maximum cable force of the inclined cable meets the expected requirements. If not, return to S103 to make appropriate adjustments to relevant parameters until the expected requirements are met; if so, the cable force is determined.

[0087] How it works

[0088] An embodiment of the present application provides a distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge and method. The tower-beam body of the distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge of the present application includes at least two bridge towers 1 spaced apart along the bridge direction, and the crossbeams of the two bridge towers 1 support steel truss main beams 2, which include a main span beam section located in the main span and a side span beam section located in the side span; a cable-stayed system, which includes double-cable-plane cable-stayed cables 3, the upper ends of the double-cable-plane cable-stayed cables 3 are anchored to the bridge tower 1, and the lower ends of the double-cable-plane cable-stayed cables 3 are anchored to both sides of the steel truss main beam 2; a suspension cable system, which includes a central main cable 4 supported on the top of the bridge tower 1 and a plurality of suspension cables 5 suspended in the central position of the main span beam section, the central main cable 4 gradually separates from the tower top to the side span direction and is dispersedly anchored in the central position of the side span beam section.

[0089] Therefore, the decentralized self-anchored central main cable steel truss girder cable-stayed and suspension-cable cooperative system bridge of the present application is primarily supported by the cable-stayed system, supplemented by the suspension cable system using the central main cable 4 and suspension cables 5 to bear part of the dead load and live load. While ensuring that the maximum cable force of the cable-stayed cable is controlled within the limit for easy manufacturing and installation, the advantages of the high structural rigidity of the steel truss main girder 2 and the cable-stayed system are maximized. The cable-stayed cable system covers the entire main span beam section, and the main girder can be cantilevered until it is closed. The through-going steel truss main girder 2 is then used as a construction platform for the decentralized self-anchored central main cable 4 and its suspension cables 5. The construction method of the steel truss main girder 2 of the present invention is essentially the same as that of a cable-stayed bridge, avoiding the problems of conventional cooperative system bridges using two different sets of construction methods and equipment, resulting in relatively high construction costs and difficulty in closing the cable-stayed and suspension areas.

[0090] In addition, the upper ends of the double-cable-plane stay cables 3 of the distributed self-anchored central main cable steel truss cable-stayed and suspension-cable collaborative system bridge of the present application are anchored to the bridge tower 1, and the lower ends of the double-cable-plane stay cables 3 are anchored to both sides of the steel truss main girder 2. The distributed self-anchored central main cable 4 and its slings 5 ​​are located in the central dividing strip of the steel truss main girder 2. The lower end of the sling 5 is hinged to the center of the main span beam section, and the upper end of the sling 5 is connected to the central main cable 4 via a main cable clamp 8. The central main cable 4 is supported by the top of the bridge tower 1, and the two ends of the central main cable 4 are respectively anchored to the anchor plates in the center of the side span beam section. The double-cable-plane stay cables 3 and the distributed self-anchored central main cable 4 and its slings 5 ​​are completely staggered in transverse spatial positions, which can effectively avoid the problem of mutual interference between the stay cables and slings within the cable-stayed and suspension-cable collaborative area.

[0091] In the description of this application, it should be noted that the terms "upper" and "lower" and the like 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 this application and simplifying the description, and do not indicate or imply 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 this 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 an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0092] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any 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 comprising 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, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0093] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. Distributed self-anchored central main cable steel truss girder cable-stayed-suspension coordinated system bridge, characterized by: include: A tower beam body, the tower beam body comprising at least two bridge towers (1) spaced apart along the longitudinal direction of the bridge, a steel truss main beam (2) supported on the cross beams (14) of the two bridge towers (1), the steel truss main beam (2) comprising a main span beam section located in the main span, and a side span beam section located in the side span; A stay cable system, the stay cable system comprising a double-cable-plane stay cable (3), the upper ends of the double-cable-plane stay cables (3) being anchored to the bridge tower (1), and the lower ends of the double-cable-plane stay cables (3) being anchored to both sides of the steel truss main beam (2); A suspension cable system, the suspension cable system comprising a central main cable (4) supported on the top of the bridge tower (1) and a plurality of suspension cables (5) suspending the center of the main span beam section, the central main cable (4) being gradually separated from the tower top toward the side span direction and then dispersedly anchored at the center of the side span beam section; The steel truss main beam (2) includes an upper bridge deck (21) and a lower bridge deck (22), and the upper chords on both sides of the upper bridge deck (21) are provided with anchor plates (23) connected to the lower ends of the double-cable-plane inclined cables (3), and the central isolation belt of the upper bridge deck (21) is provided with connecting ear plates connected to the lower ends of the suspension cables (5), and anchor plates connected to the ends of the central main cables (4).

2. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 1, characterized in that: The main span beam section comprises a cooperation zone beam section located in the middle of the span, and a cable-stayed zone beam section located at both ends of the cooperation zone beam section, and the double-cable-plane cable-stayed cable (3) covers and connects the cable-stayed zone beam section and the cooperation zone beam section; The upper end of the sling (5) is connected to the central main cable (4), and the lower end of the sling (5) is anchored at the central position of the collaboration area beam section. The double-cable-plane inclined cable (3) and the sling (5) connecting the collaboration area beam section jointly bear the dead load and live load of the collaboration area beam section.

3. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 1, characterized in that: The bridge tower (1) comprises, from top to bottom, a single-column upper tower column (11), a middle tower column (12) with a double-limb cross-section, and a lower tower column (13) with a cross-section gradually inclined inward from top to bottom. The crossbeam (14) is connected to the connecting position of the middle tower column (12) and the lower tower column (13).

4. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 3, characterized in that: The cross section of the upper tower column (11) is polygonal, the upper end of the double-cable-plane inclined cable (3) is anchored to the upper tower column (11), and the central main cable (4) is supported on the top of the upper tower column (11) through the main cable saddle and turns from the top of the upper tower column (11) toward the main span and the side span.

5. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 1 or 3, characterized in that: The central main cable (4) is composed of a plurality of parallel steel wire strands or a plurality of finished strands of sealed steel wire ropes. The central main cable (4) located on the main span side is connected to form a whole by a main cable clamp (8). The upper end of the sling (5) is connected to the main cable clamp (8). The top of the bridge tower (1) is provided with a main cable saddle for supporting the central main cable (4).

6. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 1, characterized in that: The upper bridge deck (21) is paved with an upper highway lane (25), a railway track (26) is paved at the center of the lower bridge deck (22), lower highway lanes (27) are paved on both sides of the railway track (26) on the lower bridge deck (22), and a separation zone (24) is provided between the lower highway lanes (27) and the railway track (26).

7. The distributed self-anchored central main cable steel truss girder cable-stayed and suspension coordinated system bridge according to claim 1, characterized in that: The tower beam body comprises a side pier (7) and an auxiliary pier (6) located on the side of the side span for supporting the side span beam section, wherein the side pier (7) and the auxiliary pier (6) respectively support the side span beam section through vertical supports and transverse supports.

8. A construction method for a distributed self-anchored central main cable steel truss cable-stayed and suspension coordinated bridge, characterized in that: The method is used for the distributed self-anchored central main cable steel truss cable-stayed-suspension coordinated system bridge according to any one of claims 1 to 7, and the method comprises: Constructing the bridge tower bottom foundation, the bridge tower (1), the side pier (7) and the auxiliary pier (6) at the set position; cantilevering the steel truss main beam (2) section by section on the bridge tower (1) and installing the double-cable-plane inclined cables (3), and initially adjusting the cable forces of the double-cable-plane inclined cables (3) until the steel truss main beam (2) is connected; The central main cable (4) is installed one by one using the steel truss main beam (2) after closure as a construction platform. The central main cable (4) is supported on the top of the bridge tower (1) and gradually separated from the top of the tower toward the side span and then dispersedly anchored at the center of the side span beam section. A main cable clamp (8) is installed on the main span side of the central main cable (4), and a plurality of slings (5) for suspending the main span beam section are installed on the main cable clamp (8), and the lower ends of the slings (5) are tensioned and anchored at the central position of the main span beam section; A second-phase constant load is constructed on the steel truss main beam (2), and the cable forces of the double-cable-plane inclined cables (3) and the cable forces of the sling cables (5) are adjusted synchronously to change the linear shape of the steel truss main beam (2) to a completed bridge state.

9. A method for determining cable forces in a distributed self-anchored central main cable steel truss cable-stayed-suspension coordinated system bridge, characterized in that: The method is used for the distributed self-anchored central main cable steel truss cable-stayed-suspension coordinated system bridge according to any one of claims 1 to 7, and the method comprises: Model the double-cable-plane cable-stayed bridge and determine the dead load force T of the i-th cable ih And the maximum cable force T of dead load + live load imax ; Establish the maximum cable force limit of the entire bridge [T max ], filter the maximum cable force T of the i-th inclined cable in the mid-span area imax Exceeding the maximum cable force limit [T max ] and serves as the cable-stayed cable cooperation area; The proportion of the main beam dead load shared by the i-th inclined cable within the cable force limit is set to w ,0< w <1, estimate the maximum cable force T' of the dead load + live load of the i-th inclined cable imax ; Determine whether T' is satisfied imax ≤[T max ], if not, iteratively adjust w Until T' imax ≤[T max ], if you go to the next step; According to the proportion of the main beam dead load shared by the i-th inclined cable w , determine that the ratio of the main beam dead load shared by the central main cable (4) and the sling (5) is 1- w ; According to the ratio of the main beam dead load shared by the central main cable (4) and the sling (5), 1- w Determine the specifications of the sling (5), and determine the cable force and specifications of the central main cable (4) based on the main span ratio of the main cable; Determine the number of dispersed anchorage points of the central main cable (4) in the side span according to the cable force of the central main cable (4) and the maximum main cable anchorage force at the central single point of the side span beam section; The established double-cable-plane cable-stayed bridge model was adjusted to obtain a distributed self-anchored central main cable steel truss cable-stayed-suspension cooperative system bridge; Analyze whether the maximum cable force of the inclined cable, the tension of the central main cable (4) and the sling (5) meet the expected requirements. If not, return to the corresponding position and make appropriate adjustments to the relevant parameters until the expected requirements are met.

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