Static and dynamic load control system and method for ground-anchored space cable three-tower suspension bridge

Abstract

The invention discloses a static and dynamic load control system and method for a ground-anchored space cable three-tower suspension bridge. The system comprises a ground-anchored space cable three-tower suspension bridge and a static and dynamic load control unit arranged on the ground-anchored space cable three-tower suspension bridge; the ground-anchored space cable three-tower suspension bridge comprises a main beam, a middle tower, side towers, transition piers, anchorages arranged on the main beam, and a spatial linear main cable arranged on the anchorage and the main beam; the static and dynamic load control unit comprises a shock-absorbing and energy-absorbing longitudinal limiting support arranged between the middle tower and a transverse connecting box on the main beam along the longitudinal bridge direction, a shock-absorbing and energy-absorbing wind-resistant support respectively arranged between the middle tower and the side tower and a steel box beam on the main beam along the transverse bridge direction, and a vertical support arranged at the junction of the transition pier and the steel box beam on the main beam; the flutter and wind-resistant stability of the whole bridge is improved by the spatial linear main cable; the longitudinal energy absorption capacity of the bridge is improved by the shock-absorbing and energy-absorbing longitudinal limiting support; and the transverse shock-absorbing capacity of the bridge is improved by the shock-absorbing and energy-absorbing wind-resistant support.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering, and more specifically, relates to a static and dynamic load control system and method for a ground-anchored space cable three-tower suspension bridge. Background Art

[0002] The three-tower suspension bridge is a structure in which a bridge tower is supported in the middle of the main span of the two-tower suspension bridge to reduce the main span, improve the tension of the main cable, reduce the stress on the anchors at both ends, and reduce the size of the anchors. It can reduce the overall cost and is a feasible solution for large-span bridges in wide waters. Compared with the two-tower suspension bridge, although both are load-bearing structures with suspension cables, the structural mechanical characteristics are obviously different because there is an additional middle tower and a main span. The main cable starts from the anchor point and passes through a side span and a main span to reach the middle tower. The main cable has much weaker constraints on the top of the middle tower than the side tower. When one main span is fully loaded and the other main span is underloaded or unloaded, there will be a large difference in cable force on the main cables on both sides of the middle tower.

[0003] With the increase of span, the components of the long-span space cable three-tower suspension bridge are higher, longer and more flexible, and their own stiffness is getting smaller and smaller, and the damping is getting lower and lower. The geometric nonlinear effect caused by the flexibility of the bridge structure is more prominent, and it is more sensitive to static and dynamic effects such as vehicle live load, temperature, strong wind, and earthquake. Under the most unfavorable static and dynamic effects, the main beam stress is high, the longitudinal displacement of the beam end is large, and the cumulative displacement is large. Under the action of earthquake, the internal force at the bottom of the tower is large, and the static and dynamic response of the structure is difficult to coordinate; at the same time, due to the reduction of the width-to-span ratio, the lateral stiffness is gradually reduced, affecting the flutter wind stability of the bridge. In addition, due to the lack of effective constraints of the side cables on the middle tower, the static and dynamic behavior of the long-span three-tower suspension bridge structure is significantly different from that of the double-tower suspension bridge. The constraint mode between the bridge tower and the main beam will have a great influence on the structural deformation characteristics and load transfer, and then affect the static and dynamic response of the structure. Therefore, a static and dynamic load control method and system for a ground-anchored space cable three-tower suspension bridge is needed to improve the static and dynamic force performance of a large-span ground-anchored space cable three-tower suspension bridge. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a static and dynamic load control system and method for a ground-anchored space cable three-tower suspension bridge. By arranging a spatial linear main cable and a shock-absorbing, energy-absorbing and wind-resistant bearing on the ground-anchored space cable three-tower suspension bridge, the lateral stiffness of the large-span ground-anchored space cable three-tower suspension bridge is effectively improved, the dynamic stability of the ground-anchored space cable three-tower suspension bridge is improved, and the flutter and wind-resistant stability of the entire bridge is improved; a shock-absorbing, energy-absorbing longitudinal limit bearing is arranged between the middle tower of the ground-anchored space cable three-tower suspension bridge and the transverse connecting box at the corresponding position on the main beam along the longitudinal direction of the bridge; and a shock-absorbing, energy-absorbing longitudinal limit bearing is arranged between the middle tower of the ground-anchored space cable three-tower suspension bridge and the transverse connecting box at the corresponding position on the main beam along the transverse direction of the bridge. Shock-absorbing, energy-absorbing and wind-resistant bearings are arranged between the middle tower and side tower of the suspension bridge and the steel box beams at the corresponding positions on the main beam, respectively, to effectively reduce the longitudinal and lateral displacements of the main beam of the large-span ground-anchored spatial cable three-tower suspension bridge under the action of static and dynamic loads, reduce the cumulative displacement of the beam ends under the action of automobile live load and pulsating wind, improve the lateral stiffness and flutter wind-resistant stability of the three-tower suspension bridge, reduce the difference in the internal forces of the main cables on both sides of the middle tower in the process of changing the internal forces of the main cables on both sides of the middle tower, increase the vertical stiffness of the middle tower to reduce the vertical deflection of the main beam, and reduce the seismic response of the bridge structure, thereby improving the static and dynamic stress performance of the ground-anchored spatial cable three-tower suspension bridge in the longitudinal and lateral directions of the bridge.

[0005] In order to achieve the above-mentioned object, one aspect of the present invention provides a static and dynamic load control system for a ground-anchored space cable three-tower suspension bridge, comprising a ground-anchored space cable three-tower suspension bridge and a static and dynamic load control unit arranged on the ground-anchored space cable three-tower suspension bridge; wherein,

[0006] The ground-anchored spatial cable three-tower suspension bridge comprises a main beam, a middle tower, side towers, and transition piers arranged on the main beam, anchors arranged at intervals at both ends of the main beam, and a spatial linear main cable arranged between two anchors; the main beam comprises two steel box beams arranged in parallel and at intervals along the transverse bridge direction and a plurality of transverse connection boxes arranged between the two steel box beams; the two ends of the spatial linear main cable are respectively fixedly connected to the anchors on the corresponding sides, and pass through two side towers and the top of the middle tower in the middle; the flutter and wind resistance stability of the whole bridge is improved by the spatial linear main cable;

[0007] The static and dynamic load control unit includes a shock-absorbing and energy-absorbing longitudinal limit bearing arranged between the middle tower and the transverse connecting box at the corresponding position on the main beam along the longitudinal direction of the bridge, a shock-absorbing and energy-absorbing wind-resistant bearing arranged between the middle tower and the side tower and the steel box beam at the corresponding position on the main beam along the transverse direction of the bridge, and a vertical bearing arranged at the intersection of the transition pier and the steel box beam on the main beam; the shock-absorbing and energy-absorbing longitudinal limit bearing is used to limit the longitudinal displacement of the main beam under the action of automobile live load, temperature, strong wind and earthquake, and in the process of changing the internal force of the main cable on both sides of the middle tower, the longitudinal energy absorption capacity of the bridge is improved; the shock-absorbing and energy-absorbing wind-resistant bearing is used to limit the transverse relative displacement of the middle tower and the side tower with the main beam under the action of transverse wind and transverse earthquake, and the transverse shock-absorbing capacity of the bridge is improved, thereby improving the static and dynamic force performance in the longitudinal and transverse directions of the ground-anchored space cable three-tower suspension bridge.

[0008] Furthermore, the shock-absorbing and energy-absorbing longitudinal limit bearing and the shock-absorbing and energy-absorbing wind-resistant bearing include an upper seat plate and a lower seat plate arranged in parallel and at intervals, a sliding wear-resistant plate, a rotating ball crown, a piston plate, and a plurality of disc spring assemblies arranged between the upper seat plate and the lower seat plate;

[0009] Two first side panels and two second side panels are arranged vertically upward around the top of the lower seat plate;

[0010] A plurality of friction dampers are arranged between the two first side plates and the outer side surfaces of the respective corresponding side piston plates;

[0011] The two first side plates and each friction damper on the adjacent sides are respectively provided with a lateral clamping disc spring.

[0012] Furthermore, the sliding wear-resistant plate, the rotating ball crown, the piston plate, and the disc spring assembly are arranged in sequence from top to bottom between the upper seat plate and the lower seat plate.

[0013] Furthermore, a pre-compression plate is installed between the top of the two first side plates and the side surface of the corresponding side piston plate.

[0014] Furthermore, a plurality of disc spring assemblies are evenly spaced and arranged between two opposite first side plates.

[0015] Furthermore, the disc spring assembly includes a disc spring guide rod arranged between the piston plate and the lower seat plate and a disc spring sleeved on the disc spring guide rod.

[0016] Furthermore, a plurality of reinforcement blocks are respectively provided between the first side plate, the second side plate and the lower seat plate.

[0017] Furthermore, the middle tower is arranged in the middle of the main beam; the side towers are arranged on both sides of the middle tower respectively;

[0018] The transition piers are respectively arranged at both ends of each of the steel box girders;

[0019] The spatial linear main cable is fixedly connected to the steel box girder of the main beam through a plurality of suspension rods which are arranged vertically and in parallel with each other.

[0020] Furthermore, when the shock-absorbing and energy-absorbing longitudinal limit bearing or the shock-absorbing and energy-absorbing wind-resistant bearing undergoes different displacements, the constraint force expression provided by the bearing is expressed by formula (1):

[0021]

[0022] In the formula, F r is the constraint force provided by the support; x is the displacement of the support; Δy is the displacement limit corresponding to the first-level stiffness of the support; f is the friction force provided by the friction damper in the support; F y is the maximum restraint force that the first-level stiffness of the support can provide; Δu is the total displacement limit of the support; K1 is the first-level stiffness of the support; K2 is the second-level stiffness of the support;

[0023] If the relative deformation of the tower beam is smaller than the displacement limit Δy corresponding to the primary stiffness K1 of the support, the relative displacement of the tower beam is limited by the constraint force provided by the primary stiffness K1 and the friction force provided by the friction damper; if the relative deformation of the tower beam is larger than the displacement limit Δy corresponding to the primary stiffness K1 of the support and smaller than the total displacement limit Δu of the support, the relative displacement of the tower beam is limited mainly by the constraint force provided by the secondary stiffness K2.

[0024] Another aspect of the present invention provides a method for controlling static and dynamic loads of a ground-anchored space cable three-tower suspension bridge, comprising the following steps:

[0025] S1: a shock-absorbing and energy-absorbing longitudinal limit bearing is arranged between the middle tower of the ground-anchored space cable three-tower suspension bridge and the transverse connection box at the corresponding position on the main beam along the longitudinal direction of the bridge, and a shock-absorbing and energy-absorbing wind-resistant bearing is arranged between the middle tower and the side tower of the ground-anchored space cable three-tower suspension bridge and the steel box beam at the corresponding position on the main beam along the transverse direction of the bridge;

[0026] S2: The longitudinal static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled by means of the shock-absorbing and energy-absorbing longitudinal limit bearings and the shock-absorbing and energy-absorbing wind-resistant bearings arranged on the ground-anchored space cable three-tower suspension bridge, thereby improving the static and dynamic stress performance of the large-span ground-anchored space cable three-tower suspension bridge in the longitudinal direction of the bridge; the transverse static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled by means of the shock-absorbing and energy-absorbing wind-resistant bearings arranged on the ground-anchored space cable three-tower suspension bridge, thereby improving the static and dynamic stress performance of the large-span ground-anchored space cable three-tower suspension bridge in the transverse direction of the bridge.

[0027] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0028] The static and dynamic load control system and method of the ground-anchored space cable three-tower suspension bridge of the present invention effectively improves the lateral stiffness of the ground-anchored space cable three-tower suspension bridge, improves the dynamic stability of the ground-anchored space cable three-tower suspension bridge, and enhances the flutter and wind resistance stability of the whole bridge by arranging a spatial linear main cable and a shock-absorbing energy-absorbing wind-resistant support on the ground-anchored space cable three-tower suspension bridge; and increases the ground-anchored space cable by arranging a novel shock-absorbing energy-absorbing longitudinal limit support and a novel shock-absorbing energy-absorbing wind-resistant support between the towers and beams of the ground-anchored space cable three-tower suspension bridge. The additional longitudinal stiffness and additional damping of the three-tower suspension bridge can control the displacement of the beam end of the large-span ground-anchored space cable three-tower suspension bridge under static and dynamic action, reduce the scale of the expansion joint device, reduce the cumulative displacement of the beam end under the action of automobile live load and pulsating wind, and increase the service life of the key constraint device. At the same time, in the process of changing the internal force value of the main cable on both sides of the middle tower, the internal force difference of the main cable on both sides of the middle tower is reduced, the anti-slip safety factor of the main cable is improved, and the vertical stiffness of the middle tower is improved, thereby reducing the vertical deflection of the main beam. Further, the seismic response of the structure can be reduced, and the The longitudinal seismic performance of the ground-anchored space cable three-tower suspension bridge is improved, thereby improving the longitudinal static and dynamic performance of the ground-anchored space cable three-tower suspension bridge; by setting a new type of shock-absorbing and energy-absorbing wind-resistant bearing between the towers and beams of the ground-anchored space cable three-tower suspension bridge, the lateral additional stiffness and additional damping of the ground-anchored space cable three-tower suspension bridge are increased, the lateral displacement under the action of automobiles and live load wind is limited, and driving comfort is ensured; the lateral displacement of the main beam under the action of century-old crosswind is reduced; at the same time, the shock-absorbing and energy-absorbing effect is played to reduce the lateral seismic response of the structure, thereby improving The invention can improve the transverse static and dynamic stress performance of the ground-anchored three-tower suspension bridge with spatial cable; it can solve the problems that the existing three-tower suspension bridge with spatial cable has smaller and smaller stiffness and lower damping as the span increases, the main beam has high stress, large longitudinal displacement and cumulative displacement at the beam end under the most unfavorable static and dynamic action, the internal force at the bottom of the tower is large under the action of earthquake, which makes it difficult to coordinate the static and dynamic response of the bridge structure, the flutter and wind resistance of the bridge is poor, and the middle tower lacks effective constraint of the side cables, which makes it difficult to control the static and dynamic response of the bridge structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a static and dynamic load control system for a ground-anchored space cable three-tower suspension bridge according to an embodiment of the present invention;

[0030] Figure 2 It is a structural schematic diagram of a shock-absorbing and energy-absorbing longitudinal limit bearing or a shock-absorbing and energy-absorbing wind-resistant bearing of a static and dynamic load control system of a ground-anchored spatial cable three-tower suspension bridge according to an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of a two-stage force-displacement curve of elastic stiffness of a shock-absorbing and energy-absorbing longitudinal limit bearing or a shock-absorbing and energy-absorbing wind-resistant bearing of a static and dynamic load control system of a ground-anchored spatial cable three-tower suspension bridge according to an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of a force-displacement curve of a friction damper of a shock-absorbing and energy-absorbing longitudinal limit bearing or a shock-absorbing and energy-absorbing wind-resistant bearing of a static and dynamic load control system of a ground-anchored spatial cable three-tower suspension bridge according to an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the installation position of a shock-absorbing and energy-absorbing longitudinal limit bearing or a shock-absorbing and energy-absorbing wind-resistant bearing of a static and dynamic load control system of a ground-anchored spatial cable three-tower suspension bridge according to an embodiment of the present invention;

[0034] Figure 6 The present invention is a flowchart of a method for controlling static and dynamic loads of a ground-anchored space cable three-tower suspension bridge according to an embodiment of the present invention.

[0035] In all the drawings, the same figure numbers represent the same technical features, specifically: 1-main beam, 11-steel box beam, 12-transverse connecting box, 2-middle tower, 3-side tower, 4-transition pier, 5-anchor, 6-spatial linear main cable, 7-suspender, 8-shock-absorbing and energy-absorbing longitudinal limit bearing, 81-upper seat plate, 82-lower seat plate, 83-sliding wear-resistant plate, 84-rotating ball crown, 85-piston plate, 86-several disc spring assemblies, 861-disc spring guide rod, 862-disc spring, 87-friction damper, 88-lateral clamping disc spring, 89-first side plate, 891-second side plate, 892-reinforced block, 90-pre-compression plate, 9-vertical bearing, 10-shock-absorbing and energy-absorbing wind-resistant bearing. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, when an element is referred to as being "fixed to", "disposed on" or "provided on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element; the terms "installed", "connected", "connected" and "provided with" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0038] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] like Figure 1-Figure 4 As shown, the present invention provides a static and dynamic load control system for a ground-anchored space cable three-tower suspension bridge, comprising a ground-anchored space cable three-tower suspension bridge and a static and dynamic load control unit arranged on the ground-anchored space cable three-tower suspension bridge; the ground-anchored space cable three-tower suspension bridge comprises a main beam 1, a middle tower 2, a side tower 3, a transition pier 4 arranged on the main beam 1, anchors 5 arranged at intervals at both ends of the main beam 1, and a spatial linear main cable 6 arranged between the two anchors 5; the main beam 1 comprises two steel cables arranged in parallel and at intervals along the transverse direction of the bridge; The box beam 11 and a plurality of transverse connecting boxes 12 arranged between two of the steel box beams 11; the transition piers 4 are arranged at both ends of each of the steel box beams 11; the two ends of the spatial linear main cable 6 are respectively fixedly connected to the anchor 5 on the corresponding side, and the middle passes through two side towers 3 and the top of the middle tower 2, and the spatial linear main cable 6 is fixedly connected to the steel box beam 11 of the main beam 1 through a plurality of hangers 7 arranged in parallel and spaced apart; the spatial linear main cable 6 is used to optimize the cable system of the three-tower suspension bridge and improve the three-tower suspension The lateral stiffness, torsional stiffness and torsional bending frequency ratio of the cable bridge are improved to improve the flutter and wind resistance stability of the whole bridge; the middle tower 2 is arranged in the middle of the main beam 1; the side towers 3 are arranged on both sides of the middle tower 2; the static and dynamic load control unit includes a shock-absorbing and energy-absorbing longitudinal limit bearing 8 arranged between the middle tower 2 and the transverse connecting box 12 at the corresponding position on the main beam 1 along the longitudinal bridge direction, a shock-absorbing and energy-absorbing wind-resistant bearing 10 arranged between the middle tower 2 and the side tower 3 and the steel box beam 11 at the corresponding position on the main beam 1 along the transverse bridge direction, and a The vertical support 9 at the intersection of the transition pier 4 and the steel box beam 11 on the main beam 1; the shock-absorbing and energy-absorbing longitudinal limit support 8 is used to limit the longitudinal displacement of the main beam under the action of automobile live load, temperature, strong wind and earthquake. In the process of changing the internal force of the main cables on both sides of the middle tower, the internal force difference of the main cables on both sides of the middle tower is improved, the vertical stiffness of the middle tower is increased, and the longitudinal energy absorption capacity of the bridge is improved; the shock-absorbing and energy-absorbing wind-resistant support 10 is used to limit the lateral relative displacement of the middle tower and the main beam under the action of crosswind and transverse earthquake, thereby improving the lateral shock absorption capacity of the bridge.

[0040] Furthermore, if Figure 2As shown, the shock-absorbing and energy-absorbing longitudinal limiting bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10 are both shock-absorbing and energy-absorbing bearings, which are new bearings derived from conventional wind-resistant bearings combined with shock-absorbing technology, including an upper seat plate 81 and a lower seat plate 82 arranged in parallel and spaced relation, a sliding wear-resistant plate 83, a rotating ball crown 84, a piston plate 85, and a plurality of disc spring assemblies 86 arranged between the upper seat plate 81 and the lower seat plate 82; the sliding wear-resistant plate 83, the rotating ball crown 84, the piston plate 85, and the disc spring assemblies 86 are arranged in sequence from top to bottom between the upper seat plate 81 and the lower seat plate 82; two first side plates 89 and two second side plates 891 arranged opposite to each other are arranged vertically upward around the top of the lower seat plate 82; a pre-compression plate 90 is installed between the top of the two first side plates 89 and the side of the piston plate 85 on each corresponding side; a plurality of disc spring assemblies 86 are arranged between the two opposite first side plates The plates 89 are evenly spaced apart; a plurality of friction dampers 87 are arranged between the two first side plates 89 and the outer side surfaces of the piston plates 85 on their respective corresponding sides; a lateral clamping disc spring 88 is respectively provided on the two first side plates 89 and each friction damper 87 on the adjacent sides; the disc spring assembly 86 comprises a disc spring guide rod 861 arranged between the piston plate 85 and the lower seat plate 82 and a disc spring 862 sleeved on the disc spring guide rod 861; a plurality of reinforced blocks 892 are respectively provided between the first side plate 89, the second side plate 891 and the lower seat plate 82; wherein, the upper seat plate, the rotating ball crown, the piston plate, the reinforced block, the lower seat plate and the disc spring guide rod are made of ZG270-500 or Q235, Q345 steel; the sliding wear-resistant plate and the rotating wear-resistant plate are ultra-high performance polytetrafluoroethylene plates (UHPF); and the connecting bolts are 10.9 grade high-strength hexagon socket bolts.

[0041] Furthermore, in the embodiment of the present invention, under the action of loads such as earthquakes and strong winds in the longitudinal direction of the bridge, the main beam 1 squeezes the piston plate 85 through the lower seat plate 82 of the shock-absorbing and energy-absorbing longitudinal limit support 8, and the piston plate 85 squeezes the disc spring 862 and the friction damper 87 to make reciprocating motion, providing additional elastic stiffness and additional dynamic damping for the longitudinal motion of the main beam 1 and the main tower 2, thereby effectively controlling the longitudinal phase displacement between the main beam and the main tower and the longitudinal displacement of the main beam, and improving the longitudinal energy dissipation capacity of the bridge structure. At the same time, the main beam realizes transverse and vertical motion in the transverse and vertical directions through the friction pair between the upper seat plate 81 and the rotating ball crown 84, and realizes the rotation of the main beam through the relative rotation of the rotating ball crown 84 and the piston plate 85.

[0042] Furthermore, in the embodiment of the present invention, under the action of transverse bridge earthquakes, strong winds and other loads, the main beam 1 sequentially squeezes the piston pressure plate 85 through the upper seat plate 81 and the rotating ball crown 84 of the shock-absorbing, energy-absorbing and wind-resistant support 10, and the piston plate 85 squeezes the disc spring 862 and the friction damper 87 to make reciprocating motion, thereby providing additional elastic stiffness and additional dynamic damping for the transverse movement of the main beam 1 and the middle tower and the side tower, thereby effectively reducing the transverse impact between the main beam 1 and the middle tower and the side tower, and improving the transverse shock absorption capacity of the bridge structure. At the same time, the main beam 1 realizes longitudinal and vertical movement in the longitudinal and vertical directions through the friction pair between the upper seat plate 81 and the rotating ball crown 84, and realizes the rotation of the main beam through the relative rotation of the rotating ball crown 84 and the piston plate 85;

[0043] Furthermore, in an embodiment of the present invention, the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10 are new shock-absorbing and energy-absorbing bearings, both of which are combined structures of elastic buffer devices and energy-absorbing devices, wherein the elastic buffer device can adopt a disc spring or annular spring, which mainly plays the function of elastic stiffness, including primary stiffness K1 and second-order stiffness K2; the energy-absorbing device adopts a small friction damper, which mainly plays the function of damping energy dissipation. Therefore, the new shock-absorbing and energy-absorbing bearing not only has the function of conventional bearings to transfer loads and constrain deformation, but also has the function of elastic shock absorption and energy dissipation; the elastic stiffness mechanical model and constitutive relationship of the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10 are as shown in Figure 3 The friction damper force-displacement relationship of the shock-absorbing and energy-absorbing longitudinal limit support 8 and the shock-absorbing and energy-absorbing wind-resistant support 10 is as shown Figure 4 shown.

[0044] Furthermore, in an embodiment of the present invention, when the relative deformation of the tower beam exceeds the displacement limit value corresponding to the elastic primary stiffness K1 of the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10, the secondary stiffness K2 is provided by the overall structure of the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10; when the shock-absorbing and energy-absorbing longitudinal limit bearing 8 or the shock-absorbing and energy-absorbing wind-resistant bearing 10 undergoes different displacements, the constraint force expression provided by the bearing is expressed by formula (1):

[0045]

[0046] In the formula, F r is the constraint force provided by the support; x is the displacement of the support; Δy is the displacement limit corresponding to the first-level stiffness of the support; f is the friction force provided by the friction damper in the support; F y is the maximum restraint force that the first-level stiffness of the support can provide; Δu is the total displacement limit of the support; K1 is the first-level stiffness of the support; K2 is the second-level stiffness of the support;

[0047] If the relative deformation of the tower beam is smaller than the displacement limit Δy corresponding to the primary stiffness K1 of the support, the relative displacement of the tower beam is limited by the constraint force provided by the primary stiffness K1 and the friction force provided by the friction damper; if the relative deformation of the tower beam is larger than the displacement limit Δy corresponding to the primary stiffness K1 of the support and smaller than the total displacement limit Δu of the support, the relative displacement of the tower beam is limited mainly by the constraint force provided by the secondary stiffness K2.

[0048] Further, in an embodiment of the present invention, the shock-absorbing and energy-absorbing longitudinal limit bearing 8 is arranged along the longitudinal direction of the bridge between the middle tower and the transverse connection box 12 at the corresponding position on the main beam; the shock-absorbing and energy-absorbing wind-resistant bearing 10 is arranged along the transverse direction of the bridge between the middle tower and the side tower and the steel box beam at the corresponding position on the main beam (such as Figure 5 shown).

[0049] Furthermore, in an embodiment of the present invention, the longitudinal static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are mainly controlled by the shock-absorbing energy-absorbing longitudinal limit bearing 8 and the shock-absorbing energy-absorbing wind-resistant bearing 10. Under the conditions of automobile live load and pulsating wind, the shock-absorbing energy-absorbing longitudinal limit bearing 8 and the shock-absorbing energy-absorbing wind-resistant bearing 10 work together to limit the high-frequency and low-amplitude displacement of the end of the ground-anchored space cable three-tower suspension bridge, reduce the cumulative displacement of the beam end, and increase the service life of the bearing and expansion joint. The shock-absorbing energy-absorbing longitudinal limit bearing 8 provides a large longitudinal elastic force and friction force, which plays a role. The main function is that the shock-absorbing, energy-absorbing and wind-resistant bearing 10 generates a certain friction force between the main beam and the bridge tower by applying pre-pressure, playing a secondary role; under the most unfavorable static load condition, the second-level stiffness K2 of the shock-absorbing and energy-absorbing longitudinal limit bearing 8 provides a restraining force, limits the displacement of the beam end, and reduces the scale of the expansion joint device; under the action of the design earthquake, the shock-absorbing and energy-absorbing longitudinal limit bearing 8 on the middle tower plays a limiting role to prevent excessive longitudinal displacement. At the same time, the friction damper 87 in the shock-absorbing and energy-absorbing longitudinal limit bearing 8 deforms freely within its stroke range, dissipates seismic energy, and reduces the seismic response of the structure.

[0050] Furthermore, in the embodiment of the present invention, the transverse static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are mainly controlled by the shock-absorbing energy-absorbing wind-resistant support 10. Under the action of automobiles and live-load wind, the shock-absorbing energy-absorbing wind-resistant support 10 applies pre-pressure through a plurality of disc spring assemblies 86 to provide an initial internal force to ensure that it fits tightly with the bridge tower, limits the lateral disturbance of the main beam caused by the action of automobiles and live-load wind, and ensures driving comfort; under the action of a hundred-year crosswind, the shock-absorbing energy-absorbing wind-resistant support 10 provides a limit value Δy corresponding to the first-level stiffness K1. A smaller restraining force acts as a buffer between the main beam and the pier / tower to avoid rigid collision between the main beam and the pier / tower. When the displacement of the support is greater than the displacement limit Δy corresponding to the first-level stiffness K1, the shock-absorbing, energy-absorbing and wind-resistant support provides a larger restraining force by the second-level stiffness K2 to limit the larger lateral displacement of the main beam. Under the action of lateral earthquakes, the friction damper 87 in the shock-absorbing, energy-absorbing and wind-resistant support 10 plays a role, providing a stable friction force within its total displacement limit Δu, dissipating seismic energy, reducing the lateral seismic response of the structure, and improving the lateral seismic resistance.

[0051] like Figure 6 As shown, another aspect of the present invention provides a static and dynamic load control method for a ground-anchored space cable three-tower suspension bridge, which is implemented by applying the aforementioned static and dynamic load control system for a ground-anchored space cable three-tower suspension bridge, and includes the following steps:

[0052] S1: a shock-absorbing and energy-absorbing longitudinal limit bearing 8 is arranged between the middle tower 2 of the ground-anchored space cable three-tower suspension bridge and the transverse connection box 12 at the corresponding position on the main beam 1 along the longitudinal direction of the bridge, and a shock-absorbing and energy-absorbing wind-resistant bearing 10 is arranged between the middle tower 2 and the side tower 3 of the ground-anchored space cable three-tower suspension bridge and the steel box beam 11 at the corresponding position on the main beam 1 along the transverse direction of the bridge;

[0053] S2: By means of the shock-absorbing and energy-absorbing longitudinal limit bearings 8 and the shock-absorbing and energy-absorbing wind-resistant bearings 10 arranged on the ground-anchored space cable three-tower suspension bridge, the longitudinal static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled, thereby improving the longitudinal static and dynamic stress performance of the ground-anchored space cable three-tower suspension bridge; by means of the shock-absorbing and energy-absorbing wind-resistant bearings 10 arranged on the ground-anchored space cable three-tower suspension bridge, the transverse static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled, thereby improving the transverse static and dynamic stress performance of the ground-anchored space cable three-tower suspension bridge.

[0054] Further, in an embodiment of the present invention, in step S2, controlling the longitudinal static and dynamic loads of the long-span ground-anchored space cable three-tower suspension bridge by means of the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10 provided on the ground-anchored space cable three-tower suspension bridge includes:

[0055] Under the conditions of automobile live load and pulsating wind, the shock-absorbing and energy-absorbing longitudinal limit bearing 8 and the shock-absorbing and energy-absorbing wind-resistant bearing 10 work together to limit the high-frequency and low-amplitude displacement of the end of the ground-anchored space cable three-tower suspension bridge and reduce the cumulative displacement of the beam end; wherein, the shock-absorbing and energy-absorbing longitudinal limit bearing 8 provides a large longitudinal elastic force and friction force, playing a major role, and the shock-absorbing and energy-absorbing wind-resistant bearing 10 generates a certain friction force between the main beam and the bridge tower by applying pre-pressure, playing a secondary role;

[0056] Under the most unfavorable static load condition, the second level stiffness K2 of the shock-absorbing and energy-absorbing longitudinal limit support 8 provides a restraining force, limits the displacement of the beam end, and reduces the scale of the expansion joint device;

[0057] Under the action of the design earthquake, the shock-absorbing and energy-absorbing longitudinal limit support 8 on the middle tower plays a limiting role to prevent excessive longitudinal displacement. At the same time, the friction damper 87 in the shock-absorbing and energy-absorbing longitudinal limit support 8 deforms freely within its stroke range to dissipate seismic energy and reduce the structural seismic response.

[0058] Further, in an embodiment of the present invention, in step S2, controlling the transverse static and dynamic loads of the long-span ground-anchored space cable three-tower suspension bridge by means of the shock-absorbing, energy-absorbing and wind-resistant bearing 10 provided on the ground-anchored space cable three-tower suspension bridge comprises:

[0059] Under the action of cars and live wind, the shock-absorbing and energy-absorbing wind-resistant support 10 applies pre-pressure through a plurality of disc spring assemblies 86 to provide an initial internal force, ensuring that it fits tightly with the bridge tower, limiting the lateral disturbance of the main beam caused by cars and live wind, and ensuring driving comfort;

[0060] Under the action of a hundred-year crosswind, the shock-absorbing and energy-absorbing wind-resistant bearing 10 provides a smaller restraining force within the limit value Δy corresponding to the first-level stiffness K1, and plays a buffering role between the main beam and the pier / tower to avoid rigid collision between the main beam and the pier / tower. When the displacement of the bearing is greater than the displacement limit value Δy corresponding to the first-level stiffness K1, the shock-absorbing and energy-absorbing wind-resistant bearing provides a larger restraining force by the second-level stiffness K2 to limit the larger lateral displacement of the main beam.

[0061] Under the action of lateral earthquake, the friction damper 87 in the shock-absorbing and energy-absorbing wind-resistant bearing 10 plays a role, providing a stable friction force within its total displacement limit Δu, dissipating earthquake energy, reducing the lateral earthquake response of the structure, and improving the lateral earthquake resistance.

[0062] The static and dynamic load control system and method of the ground-anchored space cable three-tower suspension bridge provided by the present invention effectively improves the lateral stiffness of the ground-anchored space cable three-tower suspension bridge, improves the dynamic stability of the ground-anchored space cable three-tower suspension bridge, and enhances the flutter and wind resistance stability of the whole bridge by arranging spatial linear main cables and shock-absorbing energy-absorbing wind-resistant bearings on the ground-anchored space cable three-tower suspension bridge; a shock-absorbing energy-absorbing longitudinal limit bearing is arranged between the middle tower of the ground-anchored space cable three-tower suspension bridge and the transverse connecting box at the corresponding position on the main beam along the longitudinal direction of the bridge; and a shock-absorbing energy-absorbing longitudinal limit bearing is arranged between the middle tower and the side tower of the ground-anchored space cable three-tower suspension bridge and the main beam along the transverse direction of the bridge. Shock-absorbing, energy-absorbing and wind-resistant bearings are arranged between the steel box girders at corresponding positions on the beams, which effectively reduce the longitudinal and lateral displacements of the main beam of the large-span ground-anchored spatial cable three-tower suspension bridge under static and dynamic loads, reduce the cumulative displacement of the beam ends under the action of automobile live load and pulsating wind, and improve the lateral stiffness and flutter wind-resistant stability of the three-tower suspension bridge. In the process of changing the internal forces of the main cables on both sides of the middle tower, the difference in the internal forces of the main cables on both sides of the middle tower is reduced, the vertical stiffness of the middle tower is increased to reduce the vertical deflection of the main beam, and the seismic response of the bridge structure is reduced, thereby improving the static and dynamic stress performance in the longitudinal and lateral directions of the ground-anchored spatial cable three-tower suspension bridge.

[0063] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A static and dynamic load control system for a ground-anchored space cable three-tower suspension bridge, characterized in that: It comprises a ground-anchored space cable three-tower suspension bridge and a static and dynamic load control unit arranged on the ground-anchored space cable three-tower suspension bridge; wherein, The ground-anchored spatial cable three-tower suspension bridge comprises a main beam (1), a middle tower (2), a side tower (3), a transition pier (4) arranged on the main beam (1), anchors (5) arranged at intervals at both ends of the main beam (1), and a spatial linear main cable (6) arranged between the two anchors (5); the main beam (1) comprises two steel box beams (11) arranged in parallel and at intervals along the transverse direction of the bridge and a plurality of transverse connection boxes (12) arranged between the two steel box beams (11); the two ends of the spatial linear main cable (6) are respectively fixedly connected to the anchors (5) on the corresponding sides, and pass through the two side towers (3) and the top of the middle tower (2); the flutter and wind resistance stability of the whole bridge is improved by the spatial linear main cable (6); The static and dynamic load control unit comprises a shock-absorbing and energy-absorbing longitudinal limit bearing (8) arranged between the middle tower (2) and the transverse connection box (12) at the corresponding position on the main beam (1) along the longitudinal direction of the bridge, a shock-absorbing and energy-absorbing wind-resistant bearing (10) arranged between the middle tower (2) and the side tower (3) and the steel box beam (11) at the corresponding position on the main beam (1) along the transverse direction of the bridge, and a vertical bearing (9) arranged at the intersection of the transition pier (4) and the steel box beam (11) on the main beam (1). The longitudinal displacement of the main beam under the action of automobile live load, temperature, strong wind and earthquake is limited by the shock-absorbing energy-absorbing longitudinal limit bearing (8), and the longitudinal energy absorption capacity of the bridge is improved in the process of changing the internal force of the main cables on both sides of the middle tower; the lateral relative displacement of the middle tower and the side tower and the main beam under the action of transverse wind and transverse earthquake is limited by the shock-absorbing energy-absorbing wind-resistant bearing (10), and the lateral shock absorption capacity of the bridge is improved, thereby improving the longitudinal and transverse static and dynamic stress performance of the ground-anchored space cable three-tower suspension bridge.

2. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 1 is characterized by: The shock-absorbing and energy-absorbing longitudinal limit bearing (8) and the shock-absorbing and energy-absorbing wind-resistant bearing (10) include an upper seat plate (81) and a lower seat plate (82) arranged in parallel and spaced relation, a sliding wear-resistant plate (83) arranged between the upper seat plate (81) and the lower seat plate (82), a rotating ball crown (84), a piston plate (85), and a plurality of disc spring assemblies (86); Two first side plates (89) and two second side plates (891) are arranged vertically upward around the top of the lower seat plate (82) and are respectively arranged opposite to each other; A plurality of friction dampers (87) are provided between the two first side plates (89) and the outer side surfaces of the corresponding side piston plates (85); The two first side plates (89) and each friction damper (87) on the adjacent side are respectively provided with a lateral clamping disc spring (88).

3. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 2 is characterized by: The sliding wear-resistant plate (83), the rotating ball crown (84), the piston plate (85), and the disc spring assembly (86) are arranged in sequence from top to bottom between the upper seat plate (81) and the lower seat plate (82).

4. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 3 is characterized by: A pre-compression plate (90) is installed between the top of the two first side plates (89) and the side surface of the corresponding side piston plate (85).

5. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 4 is characterized by: A plurality of disc spring assemblies (86) are evenly spaced and arranged between two opposite first side plates (89).

6. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 5 is characterized by: The disc spring assembly (86) includes a disc spring guide rod (861) disposed between the piston plate (85) and the lower seat plate (82) and a disc spring (862) sleeved on the disc spring guide rod (861).

7. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 6 is characterized by: A plurality of reinforcement blocks (892) are respectively provided between the first side plate (89), the second side plate (891) and the lower seat plate (82).

8. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to any one of claims 1 to 7, characterized in that: The middle tower (2) is arranged in the middle of the main beam (1); the side towers (3) are arranged on both sides of the middle tower (2); The transition piers (4) are respectively arranged at both ends of each of the steel box girders (11); The spatial linear main cable (6) is fixedly connected to the steel box girder (11) of the main beam (1) via a plurality of suspension rods (7) arranged vertically and in parallel with each other.

9. The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to claim 8 is characterized by: When the shock-absorbing and energy-absorbing longitudinal limit support (8) or the shock-absorbing and energy-absorbing wind-resistant support (10) undergoes different displacements, the constraint force expression provided by the support is expressed by formula (1): In the formula, F r is the constraint force provided by the support; x is the displacement of the support; Δy is the displacement limit corresponding to the first-level stiffness of the support; f is the friction force provided by the friction damper in the support; F y is the maximum restraint force that the first-level stiffness of the support can provide; Δu is the total displacement limit of the support; K1 is the first-level stiffness of the support; K2 is the second-level stiffness of the support; If the relative deformation of the tower beam is smaller than the displacement limit Δy corresponding to the primary stiffness K1 of the support, the relative displacement of the tower beam is limited by the constraint force provided by the primary stiffness K1 and the friction force provided by the friction damper; if the relative deformation of the tower beam is larger than the displacement limit Δy corresponding to the primary stiffness K1 of the support and smaller than the total displacement limit Δu of the support, the relative displacement of the tower beam is limited mainly by the constraint force provided by the secondary stiffness K2.

10. A method for controlling static and dynamic loads of a ground-anchored space cable three-tower suspension bridge, characterized in that: The static and dynamic load control system of the ground-anchored space cable three-tower suspension bridge according to any one of claims 1 to 9 is implemented, comprising the following steps: S1: a shock-absorbing and energy-absorbing longitudinal limit bearing (8) is arranged between the middle tower (2) of the ground-anchored space cable three-tower suspension bridge and the transverse connection box (12) at the corresponding position on the main beam (1) along the longitudinal direction of the bridge, and a shock-absorbing and energy-absorbing wind-resistant bearing (10) is arranged between the middle tower (2) and the side tower (3) of the ground-anchored space cable three-tower suspension bridge and the steel box beam (11) at the corresponding position on the main beam (1) along the transverse direction of the bridge; S2: The longitudinal static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled by means of the shock-absorbing and energy-absorbing longitudinal limit bearing (8) and the shock-absorbing and energy-absorbing wind-resistant bearing (10) provided on the ground-anchored space cable three-tower suspension bridge, thereby improving the longitudinal static and dynamic stress-bearing performance of the ground-anchored space cable three-tower suspension bridge; the transverse static and dynamic loads of the large-span ground-anchored space cable three-tower suspension bridge are controlled by means of the shock-absorbing and energy-absorbing wind-resistant bearing (10) provided on the ground-anchored space cable three-tower suspension bridge, thereby improving the transverse static and dynamic stress-bearing performance of the ground-anchored space cable three-tower suspension bridge.

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