A longitudinal vibration-joint control restraint system and method for a long-span suspension bridge

Abstract

The present invention discloses a longitudinal vibration-joint-control constraint system and method for a long-span suspension bridge. The system includes a suspension bridge and a temperature-adaptive damper module and a limit-blocking module arranged on the suspension bridge; the temperature-adaptive damper module includes a plurality of temperature-adaptive spring dampers arranged between the lower crossbeams and the main beams of two bridge towers along the longitudinal bridge direction; the limit-blocking module includes a plurality of longitudinal limit-blocking blocks arranged between the lower crossbeams and the main beams of two bridge towers along the longitudinal bridge direction; the dampers generate different constraint forces under low-speed action caused by temperature changes, medium-speed action of cars or pulsating wind, and fast working conditions caused by earthquakes, and the longitudinal limit-blocking blocks generate a constraint force that ultimately limits the longitudinal relatively large deformation between the bridge towers and the main beam under the most unfavorable load combination working condition; the longitudinal vibration-joint-control constraint of the long-span suspension bridge is realized by jointly implementing the four constraint forces; and the vibration and shock joint control of the long-span suspension bridge under different speed working conditions can be satisfied.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge engineering foundation construction, and more specifically, relates to a longitudinal vibration-joint control constraint system and method for a long-span suspension bridge. Background Art

[0002] Due to their unique structural characteristics, long-span suspension bridges have low overall stiffness and damping, making them susceptible to pulsating wind vibrations and live-load vehicle-induced vibrations. Long-term vibration during operation can lead to structural fatigue and performance degradation, and even, in extreme cases, cause accidents. Furthermore, earthquakes can cause significant deformations in the bridge structure, compromising its operational safety. Effective vibration control is crucial for ensuring bridge structural safety, extending its service life, and reducing maintenance costs. However, existing vibration control technologies still have room for improvement in terms of adaptability, efficiency, and cost-effectiveness.

[0003] To address the wind-induced vibration of long-span suspension bridges under fluctuating wind loads or vehicle-induced vibration under random traffic loads, as well as the seismic response under earthquakes, existing studies have proposed the use of cable-girder and tower-girder constraint systems. For the cable-girder constraint system, a central buckle is set in the middle of the main cable span to improve the overall longitudinal stiffness of the bridge. However, previous studies have shown that its control effect on the cumulative displacement of the beam end under fluctuating wind and random traffic loads is limited, and it also increases the stress amplitude of the broken cable, posing fatigue problems. For the elastic constraint system in the tower-girder constraint system, a reasonable longitudinal additional stiffness is directly set between the tower and the beam. Although it can effectively control the cumulative displacement of the beam end under fluctuating wind and random traffic loads, it will introduce significant temperature stress in the main beam under slow temperature conditions and may increase the internal force of the bridge foundation structure under fast earthquake conditions, which is not conducive to earthquake resistance. For the damping system in the tower-girder constraint system, a longitudinal damper is directly set between the tower and the beam. However, under medium and low speed conditions such as fluctuating wind and random traffic, the constitutive relationship of the damping output does not satisfy the CV equation. α , the actual vibration control effect will be greatly reduced, and it can only play a good damping and energy dissipation role under rapid earthquake conditions.

[0004] With the development of engineering technology and the increasing requirements for bridge performance, new technologies need to be developed to cope with more complex and changing engineering environments. This requires that bridge vibration control systems not only perform well under normal operating conditions, but also provide reliable protection under extreme conditions.

[0005] Therefore, traditional long-span suspension bridge restraint systems and vibration control methods cannot simultaneously meet different speed conditions, or the vibration (or oscillation) control effect is unsatisfactory. There is an urgent need for a longitudinal vibration-vibration combined control restraint system that can meet the vibration / oscillation control problems of long-span suspension bridges under different speed conditions. Summary of the Invention

[0006] In response to the above-mentioned deficiencies or improvement needs in the prior art, the present invention provides a longitudinal vibration-coordinated control and restraint system and method for a long-span suspension bridge. By disposing a longitudinal vibration-coordinated control and restraint system consisting of a temperature-adaptive spring damper with separated spring and damping outputs under different speed conditions and a longitudinal limit block between the bridge tower and the main beam, effective control of the vibration and deformation of the long-span suspension bridge under different speed conditions is achieved. The longitudinal additional stiffness and additional damping of the bridge are effectively improved. By optimizing parameters such as the constant damping force, spring stiffness, damping coefficient, speed index, and limit gap that the damper can provide, the system is used to suppress the high-frequency, low-amplitude reciprocating vibration of the main beam under medium-speed conditions such as fluctuating wind and random traffic loads. The system is also used to control the large longitudinal deformation of the main beam under rapid earthquake conditions, thereby reducing the cumulative displacement and longitudinal displacement response of the beam ends. This improves the service durability of key restraint devices (supports, dampers), reduces the design and construction scale of the expansion and contraction device, improves the mechanical behavior and stress-bearing performance of the bridge, and enhances the safety of the actual long-span suspension bridge engineering structure and the economic efficiency throughout its life cycle. The present invention can automatically adjust its output performance according to changes in the external environment and load speed to adapt to different working conditions.

[0007] To achieve the above objectives, one aspect of the present invention provides a longitudinal vibration joint control and restraint system for a long-span suspension bridge, comprising a suspension bridge and a temperature-adaptive damper module and a position-limiting and blocking module disposed on the suspension bridge; the suspension bridge comprises two bridge towers arranged in parallel and spaced relation, a main cable, a suspender rod, a main beam disposed between the two bridge towers, and an anchor disposed on a side of each bridge tower away from the main beam; the main cable passes through the tops of the two bridge towers and is anchored at both ends to the two anchor rods; the main beam is connected to the main cable via a plurality of suspenders arranged in parallel and spaced relation;

[0008] The temperature adaptive damper module includes a plurality of temperature adaptive spring dampers arranged between the lower cross beam 9 of the two bridge towers and the main beam along the longitudinal bridge direction; the temperature adaptive spring damper does not generate a constraint force when acting at low speed caused by temperature changes, and can achieve temperature adaptation of the main beam deformation; under the medium speed action of cars or pulsating wind, the temperature adaptive spring damper can generate a second constraint force to suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working condition caused by earthquake, it can generate a third constraint force to reduce the relatively large longitudinal deformation between the bridge tower and the main beam; the limit blocking module includes a plurality of longitudinal limit blocks arranged between the lower cross beam of the two bridge towers and the main beam along the longitudinal bridge direction; under the combined action of the most unfavorable working conditions, it can generate a fourth constraint force that ultimately limits the relatively large longitudinal deformation between the bridge tower and the main beam; the longitudinal vibration-vibration joint control constraint of the long-span suspension bridge is realized through the four constraint forces.

[0009] Furthermore, the suspension bridge is also provided with vertical supports; the vertical supports are all fixedly arranged between the lower cross beam and the main beam of the bridge tower.

[0010] Furthermore, the temperature adaptive spring damper includes a cylinder, a piston rod arranged in the cylinder, two end covers arranged on the cylinder, three pistons arranged between the two end covers, springs respectively arranged between two adjacent piston rods, and limit nuts tightly arranged on the two outer pistons and rigidly connected to the piston rods.

[0011] Furthermore, a damping medium is provided in the cylinder; damping valves connected to the interior of the cylinder are respectively provided on the two end covers and the piston located in the middle; an oil return channel is provided between the damping valves on the two end covers; the middle piston among the three pistons is rigidly connected to the piston rod, and the other two pistons can slide along the piston rod; and flow holes are respectively provided on the three pistons.

[0012] Furthermore, under the low-speed action caused by temperature changes, the damping medium can flow freely through the flow holes on the three pistons, thereby realizing temperature adaptation of the deformation of the bridge tower and the main beam; under the medium-speed action of cars or pulsating wind, the spring force provided by any one of the two springs and the constant damping force provided by any one of the two pistons on both sides jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working conditions caused by earthquakes, the limit function of the pistons on both sides and the damping energy dissipation function of the middle piston, as well as the fuse function of any one of the damping valves on the two end covers, realize the shock absorption and energy dissipation of the damping system under strong earthquakes, thereby reducing the relatively large longitudinal deformation between the bridge tower and the main beam.

[0013] A second aspect of the present invention provides a longitudinal vibration-vibration joint control and restraint method for a long-span suspension bridge, which is implemented using the longitudinal vibration-vibration joint control and restraint system for a long-span suspension bridge, and includes the following steps:

[0014] S1: A temperature-adaptive spring damper is provided on the suspension bridge, so that the temperature-adaptive spring damper generates a first restraining force under the low-speed action caused by temperature, thereby realizing self-adaptation of the main beam deformation under temperature stress;

[0015] S2: By installing a temperature-adaptive spring damper on the suspension bridge, the temperature-adaptive spring damper generates a second restraining force to suppress the longitudinal high-frequency, low-amplitude reciprocating vibration of the main beam end under the action of medium speed caused by cars and pulsating wind;

[0016] S3: by arranging a temperature-adaptive spring damper on the suspension bridge, the temperature-adaptive spring damper generates a third restraining force under the rapid action of an earthquake to reduce the longitudinal relative large deformation between the bridge tower and the main beam of the long-span suspension bridge;

[0017] S4: By providing longitudinal limit blocks on the suspension bridge, under the most unfavorable load combination conditions, the longitudinal limit blocks generate a fourth restraining force to ultimately limit the longitudinal relative large deformation between the tower and the main beam of the long-span suspension bridge, thereby reducing the size of the beam end expansion and contraction device;

[0018] S5: The longitudinal vibration-vibration joint control constraint of the long-span suspension bridge is achieved through the first constraint force generated by the temperature adaptive spring damper under the low-speed action caused by temperature changes, the second constraint force generated by the temperature adaptive spring damper under the medium-speed action caused by cars and pulsating wind, and the third constraint force generated by the temperature adaptive spring damper under the fast action caused by earthquakes; under the most unfavorable load combination working condition, the longitudinal limit block generates the fourth constraint force.

[0019] Furthermore, the self-adaptation of the main beam deformation under the main beam temperature stress in step S1 specifically includes:

[0020] The three pistons of the temperature-adaptive spring damper are respectively provided with flow holes. Under the low-speed action caused by temperature, the damping medium on the temperature-adaptive spring damper flows freely through the flow holes. The temperature-adaptive spring damper is longitudinally free and no additional constraint force is generated, that is, the first constraint force is zero. The damper does not generate temperature stress, thereby realizing the self-adaptation of the long-span suspension bridge to the temperature deformation of the main beam.

[0021] Furthermore, the step S2 of suppressing the longitudinal high-frequency low-amplitude reciprocating vibration of the main beam end specifically includes:

[0022] Springs are respectively arranged on two adjacent pistons of the three pistons of the temperature-adaptive spring damper. When relative deformation occurs between the bridge tower and the main beam under the action of medium speed caused by cars and pulsating wind, the springs can provide spring force. At the same time, the pistons can provide constant damping force. The spring constraint force generated by the spring of the temperature-adaptive spring damper and the constant damping force generated by the pistons together constitute a second constraint force to reduce the high-frequency, low-amplitude reciprocating vibration of the main beam.

[0023] Furthermore, reducing the longitudinal relative large deformation between the tower and the main beam of the long-span suspension bridge in step S3 specifically includes:

[0024] Damping valves are installed on the two end covers and the piston in the middle position of the temperature-adaptive spring damper. Under the rapid action of an earthquake, the three pistons of the temperature-adaptive spring damper provide damping force to form a third constraint force to reduce the large longitudinal deformation between the bridge tower and the main beam.

[0025] Furthermore, the restraining force provided by the temperature adaptive spring damper is expressed by formula (1):

[0026]

[0027] Where v is the velocity of the load on the suspension bridge, k is the elastic stiffness provided by the temperature-adaptive spring damper, x is the relative deformation displacement between the bridge tower and the main beam, and F h is the constant damping force provided by the pistons on both sides of the temperature adaptive spring damper, C is the damping coefficient of the temperature adaptive spring damper, α is the velocity index of the temperature adaptive spring damper, and V is the relative deformation velocity between the bridge tower and the main beam.

[0028] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0029] (1) The present invention provides a longitudinal vibration joint control constraint system and method for a long-span suspension bridge. The system uses a plurality of temperature-adaptive spring dampers, longitudinal limit blocks and vertical supports between the lower crossbeam of the bridge tower and the main beam of the suspension bridge. The temperature-adaptive spring dampers suppress the high-frequency, low-amplitude reciprocating vibration of the main beam under medium-speed load conditions such as pulsating wind or random traffic, and reduce the rapid action caused by earthquakes that causes relatively large longitudinal deformation between the bridge tower and the main beam. The longitudinal limit blocks ultimately limit the longitudinal displacement of the main beam to prevent excessive deformation. The vertical supports provide vertical support to maintain the stability of the bridge structure. The present invention sets temperature-adaptive spring dampers between the bridge tower and the main beam to separate the spring output and the damping output under different speed conditions. The longitudinal vibration-controlled constraint system of spring dampers and longitudinal limit blocks effectively improves the longitudinal additional stiffness and additional damping of the bridge. By optimizing parameters such as the constant damping force, spring stiffness, damping coefficient, velocity index and limit gap that the damper can provide, it is used to suppress the high-frequency, low-amplitude reciprocating vibration of the main beam under medium-speed conditions such as pulsating wind and random traffic loads. It is also used to control the large longitudinal deformation of the main beam under rapid earthquake conditions, which can reduce the cumulative displacement and longitudinal displacement response of the beam end, thereby improving the service durability of key constraint devices (supports, dampers, expansion joints), reducing the design and construction scale of expansion devices, improving the mechanical behavior and stress performance of the bridge, and enhancing the safety of the actual large-span suspension bridge engineering structure and the economy of the entire life cycle.

[0030] (2) The present invention provides a longitudinal vibration-controlled restraint system and method for a long-span suspension bridge. The temperature-adaptive spring damper does not generate a restraining force at low speeds caused by temperature changes, and can achieve temperature adaptation of the main beam deformation. Under the medium-speed action of cars or pulsating wind, the temperature-adaptive spring damper can generate a second restraining force to suppress the high-frequency, low-amplitude reciprocating vibration of the bridge beam end caused by the live load of cars and pulsating wind. Under the fast working condition caused by earthquakes, it can generate a third restraining force to reduce the longitudinal relatively large deformation between the bridge tower and the main beam. Under the most unfavorable load combination working condition, the longitudinal limit block can generate a fourth restraining force that ultimately limits the longitudinal relatively large deformation between the bridge tower and the main beam. The long span is achieved through the four restraining forces. Longitudinal vibration-vibration joint control constraint of suspension bridges; the present invention integrates vibration and shock control under different speed conditions into a damping device, and suppresses the high-frequency and low-amplitude reciprocating vibration of the main beam and controls the large longitudinal deformation under earthquake by optimizing the parameters of the damper (such as damping coefficient, velocity index, etc.) in medium-speed conditions under pulsating wind and random traffic loads, as well as rapid earthquake conditions; by reducing the cumulative displacement and longitudinal displacement response of the beam end, the service durability of key devices such as supports, dampers, expansion joints, etc. is improved, and the design and construction scale of the expansion device is reduced; by optimizing the design, maintenance costs are reduced, and the full life cycle economy of the bridge is improved; the overall adaptability, reliability and economy of the system are improved, and it can be promoted and applied to other bridge types such as suspension bridges. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a longitudinal vibration-coordinated control restraint system for a long-span suspension bridge according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a longitudinal bridge direction of a longitudinal vibration-coordinated control restraint system for a long-span suspension bridge according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic structural diagram of a temperature-adaptive spring damper of a longitudinal vibration-coordinated restraint system for a long-span suspension bridge according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic top view of the structure of a longitudinal vibration-coordinated control restraint system for a long-span suspension bridge according to an embodiment of the present invention;

[0035] Figure 5 The figure is a flow chart of a method for longitudinal vibration-joint control and constraint of a long-span suspension bridge according to an embodiment of the present invention.

[0036] In all the drawings, the same reference numerals represent the same technical features, specifically: 1-bridge tower, 2-main cable, 3-suspender, 4-main beam, 5-anchor, 6-temperature adaptive spring damper, 61-cylinder, 62-piston rod, 63-piston, 64-spring, 65-limiting nut, 7-longitudinal limit block, 8-vertical support, 9-lower crossbeam. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate 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 may be combined with each other as long as they do not conflict with each other.

[0038] like Figures 1-4 As shown, one aspect of the present invention provides a longitudinal vibration joint control restraint system for a long-span suspension bridge, comprising a suspension bridge and a temperature-adaptive damper module and a limit blocking module arranged on the suspension bridge; the suspension bridge comprises two bridge towers 1 arranged in parallel and at intervals, a main cable 2, a suspender 3, a main beam 4 arranged between the two bridge towers 1, and an anchor 5 arranged on the side of each bridge tower 1 away from the main beam 4; the main cable 2 passes through the top of the two bridge towers 1 and anchors both ends to the two anchors 5; the main beam 4 is connected to the main cable 2 through a number of suspenders 3 arranged in parallel and at intervals; the temperature-adaptive damper module comprises a number of temperature-adaptive spring dampers 6 arranged between the lower cross beams 9 of the two bridge towers 1 and the main beam 4 along the longitudinal bridge direction; the limit blocking module comprises a number of longitudinal limit blocks 7 arranged between the lower cross beams 9 of the two bridge towers 1 and the main beam 4 along the longitudinal bridge direction; the temperature The temperature-adaptive spring damper 6 is used to suppress the high-frequency, low-amplitude reciprocating vibration of the main beam 4 under medium-speed load conditions such as pulsating wind or random traffic flow, and to reduce the relatively large longitudinal deformation between the bridge tower 1 and the main beam 4 caused by the rapid action caused by earthquakes; the temperature-adaptive spring damper 6 can achieve temperature adaptation of the main beam deformation under low-speed action caused by temperature changes; under the medium-speed action of cars or pulsating wind, it can generate a second constraint force to suppress the high-frequency, low-amplitude reciprocating vibration of the bridge beam end caused by car live loads and pulsating wind; under the rapid working conditions caused by earthquakes, it can generate a third constraint force to achieve shock absorption and energy consumption of the damper under strong earthquakes, thereby reducing the relatively large longitudinal deformation between the bridge tower 1 and the main beam 4; under the most unfavorable working conditions, the longitudinal limit block 7 can generate a fourth constraint force to limit the relatively large longitudinal deformation between the bridge tower 1 and the main beam 4, thereby ultimately limiting the relatively large longitudinal deformation between the bridge tower 1 and the main beam 4.

[0039] Furthermore, if Figures 1-4As shown, the bridge tower 1 is the main supporting structure of the suspension bridge, located at both ends of the bridge, and its height and stability directly affect the bearing capacity of the entire bridge; the top of the bridge tower is used to anchor the main cable 2, ensuring that the tension of the main cable 2 is evenly distributed, thereby supporting the entire bridge structure; the main cable 2 is the main load-bearing component of the suspension bridge, supporting the weight of the entire bridge through its tension; the main cable 2 transfers the load from the bridge deck to the bridge tower 1 and the anchor 5, and is the key force transmission path in the bridge structure; the hanger 2 connects the main beam 4 with the main cable 2, so that the load of the main beam 4 is transferred to the main cable 2 through the hanger 3; the hanger 3 not only It transfers loads and supports the main beam 4 through its own stiffness and strength to maintain the stability of the bridge. The main beam 4 is the upper structure of the bridge and directly bears traffic loads such as vehicles and pedestrians. The main beam 4 is connected to the main cable 2 through the hanger 3, transferring the load to the main cable 2, and then to the bridge tower 1 and the anchor 5 through the main cable 2. The anchor 5 is the end anchorage point of the main cable 2, usually located at both ends of the bridge. Its function is to fix the main cable 2 and ensure that the tension of the main cable 2 is evenly distributed. The anchor 5 provides additional stability for the entire bridge through its huge weight and structural stability to prevent the main cable 2 from sliding or loosening.

[0040] Furthermore, if Figures 1-4 As shown, the suspension bridge is further provided with vertical supports 8; the vertical supports 8 are all fixedly arranged between the lower cross beam 9 of the bridge tower 1 and the main beam 4; the vertical supports 8 can absorb and disperse the vertical forces caused by traffic loads, wind loads or earthquakes, etc., to reduce the impact on the bridge structure; the vertical supports 8 provide stability of the bridge in the vertical direction, ensuring that the bridge remains stable when subjected to vertical loads; the vertical supports 8 can prevent the main cable from directly bearing the vertical load, thereby protecting the main cable from excessive pressure or tension.

[0041] Furthermore, if Figures 1-4As shown, the temperature adaptive spring damper 6 includes a cylinder 61, a piston rod 62 arranged in the cylinder 61, two end covers arranged on the cylinder 61, three pistons 63 arranged between the two end covers, springs 64 respectively arranged between two adjacent piston rods 63, and a limit nut 65 tightly attached to the two outer pistons 63 and rigidly connected to the piston rod 62; a damping medium is provided in the cylinder 61; the two end covers and the piston located in the middle are respectively provided with a damping valve connected to the interior of the cylinder 61; an oil return channel is provided between the damping valves on the two end covers; the piston located in the middle of the three pistons is rigidly connected to the piston rod 62, and the other two pistons can slide along the piston rod 62; the three pistons are respectively provided with a Flow hole; under the low-speed action caused by temperature change, the damping medium can flow freely through the flow holes on the three pistons, realizing temperature adaptation of the deformation of the bridge tower 1 and the main beam 4; under the medium-speed action of the car or pulsating wind, the spring force provided by any one of the two springs and the constant damping force provided by any one of the two pistons on both sides jointly suppress the high-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working condition caused by the earthquake, the limit function of the pistons on both sides and the damping energy dissipation function of the middle piston, as well as the fuse function of any one of the damping valves on the two end covers, realize the shock absorption and energy dissipation of the damping system under strong earthquake, thereby reducing the relatively large longitudinal deformation between the bridge tower 1 and the main beam 4.

[0042] like Figure 5 As shown, another aspect of the present invention provides a longitudinal vibration-vibration joint control and restraint method for a long-span suspension bridge, which is implemented by applying the aforementioned longitudinal vibration-vibration joint control and restraint system for a long-span suspension bridge, and includes the following steps:

[0043] S1: By arranging a temperature-adaptive spring damper 6 on the suspension bridge, the temperature-adaptive spring damper 6 generates a first restraining force under the low-speed action (v < 0.01 mm / s) caused by temperature, thereby realizing self-adaptation of the main beam deformation under temperature stress;

[0044] S2: By installing a temperature-adaptive spring damper 6 on the suspension bridge, the suspension bridge is subjected to medium-speed action (0.01 mm / s < v < 10 mm / s) caused by automobiles and pulsating wind. The temperature-adaptive spring damper 6 generates a second restraining force to suppress the longitudinal high-frequency, low-amplitude reciprocating vibration of the end of the main beam 4;

[0045] S3: By arranging a temperature-adaptive spring damper 6 on the suspension bridge, the temperature-adaptive spring damper 6 generates a third restraining force under the rapid action (v>80 mm / s) caused by an earthquake to reduce the longitudinal relative large deformation between the tower 1 and the main beam 4 of the long-span suspension bridge;

[0046] S4: By disposing a plurality of longitudinal limit blocks 7 along the longitudinal direction of the bridge between the lower cross beams 9 of the two towers 1 and the main beam 4 on the suspension bridge, the longitudinal limit blocks 7 generate a fourth restraining force under the most unfavorable load combination working condition of the suspension bridge to ultimately limit the longitudinal relative large deformation between the towers 1 and the main beam 4 of the long-span suspension bridge, thereby reducing the scale of the beam end expansion and contraction device;

[0047] S5: The longitudinal vibration-controlled constraint of the long-span suspension bridge is achieved through the first constraint force generated by the temperature adaptive spring damper 6 under the low-speed action caused by temperature change, the second constraint force generated by the temperature adaptive spring damper 6 under the medium-speed action caused by cars and pulsating wind, the third constraint force generated by the temperature adaptive spring damper 6 under the fast action caused by earthquakes, and the fourth constraint force generated by the longitudinal limit block 7 under the most unfavorable load combination working condition.

[0048] Furthermore, the self-adaptation of the main beam deformation under the temperature stress of the main beam 4 in step S1 specifically includes:

[0049] The three pistons of the temperature-adaptive spring damper 6 are respectively provided with flow holes. When the suspension bridge is subjected to low-speed action caused by temperature (v < 0.01 mm / s), the damping medium on the temperature-adaptive spring damper (6) flows freely through the flow holes. The temperature-adaptive spring damper 6 is longitudinally free and no additional constraint force is generated, that is, the first constraint force is zero. The damper does not generate temperature stress, thereby realizing the self-adaptation of the long-span suspension bridge to the temperature deformation of the main beam.

[0050] Furthermore, the step S2 of suppressing the longitudinal high-frequency low-amplitude reciprocating vibration of the beam end of the main beam 4 specifically includes:

[0051] A spring is provided on two adjacent pistons of the three pistons of the temperature-adaptive spring damper 6. When the suspension bridge is subjected to medium-speed action (0.01 mm / s < v < 10 mm / s) caused by automobiles and pulsating wind, when relative deformation occurs between the bridge tower 1 and the main beam 4, the spring can provide spring force. At the same time, the piston can provide a constant damping force. The spring constraint force generated by the spring of the temperature-adaptive spring damper 6 and the constant damping force generated by the piston together constitute a second constraint force to reduce the high-frequency, low-amplitude reciprocating vibration of the main beam 4.

[0052] Furthermore, reducing the longitudinal relative large deformation between the tower 1 and the main beam 4 of the long-span suspension bridge in step S3 specifically includes:

[0053] Damping valves are respectively provided on the two end covers and the piston in the middle position of the temperature-adaptive spring damper 6. Under the rapid action of an earthquake (v>80mm / s), the three pistons of the temperature-adaptive spring damper 6 respectively provide damping force to form a third restraining force to reduce the large longitudinal deformation between the bridge tower 1 and the main beam 4.

[0054] Furthermore, the final restriction of the longitudinal relative large deformation between the bridge tower 1 and the main beam 4 of the long-span suspension bridge in step S4 specifically includes: by setting a reasonable limit gap between the longitudinal limit blocks respectively arranged between the bridge tower 1 and the main beam 4, under the most unfavorable load combination working condition, the longitudinal limit blocks 7 provide a fourth constraint force to ultimately restrict the longitudinal relative large deformation between the bridge tower 1 and the main beam 4.

[0055] Furthermore, in step S5, the first constraint force is zero, which can realize the self-adaptation of the main beam deformation under temperature stress; the second constraint force includes the spring constraint force generated by the spring and the constant damping force generated by the piston, which can suppress the longitudinal high-frequency low-amplitude reciprocating vibration of the beam end of the main beam 4; the third constraint force includes three damping forces generated by three pistons, which can reduce the longitudinal relatively large deformation between the bridge tower 1 and the main beam 4 of the long-span suspension bridge; the fourth constraint force can ultimately limit the longitudinal large deformation between the bridge tower 1 and the main beam 4, reduce the scale of the beam end expansion device, and realize the longitudinal vibration joint control constraint of the long-span suspension bridge through the four constraint forces; the constraint force provided by the temperature-adaptive spring damper 6 is expressed by formula (1):

[0056]

[0057] Where v is the velocity of the load on the suspension bridge, k is the elastic stiffness provided by the temperature-adaptive spring damper 6, x is the relative deformation displacement between the bridge tower 1 and the main beam 4, and F h is the constant damping force provided by the pistons on both sides of the temperature adaptive spring damper 6, C is the damping coefficient of the temperature adaptive spring damper 6, α is the velocity index of the temperature adaptive spring damper 6, and V is the relative deformation velocity between the bridge tower 1 and the main beam 4.

[0058] The present invention provides a longitudinal vibration-controlled restraint system for a long-span suspension bridge, which adopts a temperature-adaptive spring damper 6 that can automatically adjust its performance under temperature changes. The temperature-adaptive spring damper is designed as a three-piston structure, a spring is arranged between the pistons, and the combination of the spring and the piston provides spring force and constant damping force. Under the action of temperature, the spring does not generate a reaction force, thereby releasing the deformation of the main beam caused by the temperature effect. The spring and the piston respectively provide spring force and constant damping force, which can more effectively suppress the high-frequency, low-amplitude reciprocating vibration of the beam end caused by live loads, and can also achieve the ideal vibration reduction effect of a small damping index damper. Under earthquakes, the pistons on both sides are similar to hydraulic springs, playing a limiting function, and the middle piston plays a damping energy dissipation role. Under the action of impact loads such as braking force and pulsating wind, the spring will provide a reset force and has a certain self-reset function. At the same time, the three-piston structure design, the two outer pistons can play a floating support role, which can improve the anti-buckling stability, thereby improving the durability of the device. The three-piston structure makes the overall friction hot spots more uniform and the heat distribution more uniform. A damping valve fuse unit is set on the piston in the middle position to prevent the damper from being affected by the excessive oil pressure in the cylinder during strong earthquakes. A number of longitudinal limit blocks 7 are set between the lower cross beam 9 of the two bridge towers 1 and the main beam 4 along the longitudinal bridge direction to ultimately limit the longitudinal relative large deformation between the bridge tower 1 and the main beam 4, thereby effectively reducing the scale of the beam end telescopic device. The present invention combines the vibration and vibration control under different speed conditions into one damping device, which can be used in medium-speed conditions under pulsating wind and random traffic loads, fast earthquake conditions, and Under the most unfavorable combined working conditions, the high-frequency, low-amplitude reciprocating vibration of the main beam is suppressed by optimizing the parameters of the damper (such as the damping coefficient, velocity index, etc.), and the large longitudinal deformation under earthquakes is controlled; by reducing the cumulative displacement and longitudinal displacement response of the beam end, the service durability of key devices such as supports, dampers, and expansion joints is improved, and the design and construction scale of the expansion device is reduced; by optimizing the design, maintenance costs are reduced, and the economy of the bridge throughout its life cycle is improved; the overall adaptability, reliability, and economy of the system are improved, and it can be promoted and applied to other bridge types such as suspension bridges.

[0059] 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 scope of protection of the present invention.

Claims

1. A longitudinal vibration-controlled restraint system for a long-span suspension bridge, characterized by: The invention comprises a suspension bridge and a temperature-adaptive damper module and a position-limiting blocking module arranged on the suspension bridge; the suspension bridge comprises two bridge towers (1) arranged in parallel and at intervals, a main cable (2), a suspender (3), a main beam (4) arranged between the two bridge towers (1), and an anchor (5) arranged on the side of each bridge tower (1) away from the main beam (4); the main cable (2) passes through the top of the two bridge towers (1) and anchors both ends to the two anchors (5); the main beam (4) is connected to the main cable (2) through a plurality of suspenders (3) arranged in parallel and at intervals; the temperature-adaptive damper module and the position-limiting blocking module are ... The damper module comprises a plurality of temperature-adaptive spring dampers (6) arranged between the lower cross beams (9) of the two bridge towers (1) and the main beam (4) along the longitudinal bridge direction; the temperature-adaptive spring dampers (6) are capable of separating spring output and damping output under different speed conditions; the temperature-adaptive spring dampers (6) comprise a cylinder (61), a piston rod (62) arranged in the cylinder (61), two end covers arranged on the cylinder (61), three pistons (63) arranged between the two end covers, and springs (64) respectively arranged between two adjacent piston rods (63), which are closely attached to the cylinder (61). A limit nut (65) is provided on the two outer pistons (63) and rigidly connected to the piston rod (62); a damping medium is provided in the cylinder (61); damping valves communicating with the interior of the cylinder (61) are provided on the two end covers and the piston located in the middle; an oil return passage is provided between the damping valves on the two end covers; the piston located in the middle of the three pistons is rigidly connected to the piston rod (62), and the other two pistons can slide along the piston rod (62); flow holes are provided on the three pistons; when a low-speed action is caused by temperature change, the damping medium can flow freely through the flow holes on the three pistons, thereby achieving The deformation of the bridge tower (1) and the main beam (4) is temperature-adaptive; under the medium-speed action of a car or pulsating wind, the spring force provided by any one of the two springs and the constant damping force provided by any one of the two pistons on both sides jointly suppress the low-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working condition caused by an earthquake, the damping energy dissipation of the damping system under strong earthquakes is achieved through the limiting function of the pistons on both sides and the damping energy dissipation function of the middle piston, as well as the fuse function of any one of the damping valves on the two end covers; thereby reducing the relatively large longitudinal deformation between the bridge tower (1) and the main beam (4); The temperature-adaptive spring damper (6) does not generate a restraining force when acting at low speeds caused by temperature changes, and can achieve temperature adaptation of the main beam deformation; under the medium-speed action of a car or pulsating wind, the temperature-adaptive spring damper (6) can generate a second restraining force to suppress the low-frequency and low-amplitude reciprocating vibration of the bridge beam end caused by the live load of the car and the pulsating wind; under the fast working condition caused by an earthquake, it can generate a third restraining force to reduce the relatively large longitudinal deformation between the bridge tower (1) and the main beam (4); The limit blocking module includes a plurality of longitudinal limit blocks (7) provided between the lower cross beams (9) of the two bridge towers (1) and the main beam (4) along the longitudinal bridge direction; under the combined action of the most unfavorable working conditions, a fourth constraint force can be generated to ultimately limit the longitudinal relative large deformation between the bridge towers (1) and the main beam (4); the longitudinal vibration-joint control constraint of the long-span suspension bridge is achieved through the four constraint forces; The restraining force provided by the temperature adaptive spring damper (6) is expressed by formula (1): （1） Where, v is the speed of the load on the suspension bridge, k The elastic stiffness provided by the temperature-adaptive spring damper (6), x is the relative deformation displacement between the bridge tower (1) and the main beam (4), F h The constant damping force provided by the pistons on both sides of the temperature adaptive spring damper (6) is C is the damping coefficient of the temperature adaptive spring damper (6), is the velocity exponent of the temperature adaptive spring damper (6), V is the relative deformation velocity between the bridge tower (1) and the main beam (4).

2. The longitudinal vibration-coordinated restraint system for a long-span suspension bridge according to claim 1, characterized in that: The suspension bridge is also provided with vertical supports (8); the vertical supports (8) are all fixedly arranged between the lower cross beam (9) and the main beam (4) of the bridge tower (1).

3. A longitudinal vibration-induced joint control constraint method for a long-span suspension bridge, characterized in that: The longitudinal vibration-joint control restraint system for a long-span suspension bridge as claimed in claim 1 or 2 is applied to implement the system, comprising the following steps: S1: by arranging a temperature-adaptive spring damper (6) on the suspension bridge, the temperature-adaptive spring damper (6) generates a first restraining force under the low-speed action caused by temperature, thereby realizing self-adaptation of the main beam deformation under temperature stress; S2: By arranging a temperature-adaptive spring damper (6) on the suspension bridge, the temperature-adaptive spring damper (6) generates a second restraining force to suppress the longitudinal low-frequency and low-amplitude reciprocating vibration of the beam end of the main beam (4) under the action of medium speed caused by cars and pulsating wind; S3: By arranging a temperature-adaptive spring damper (6) on the suspension bridge, the temperature-adaptive spring damper (6) generates a third restraining force under the rapid action caused by an earthquake to reduce the longitudinal relative large deformation between the bridge tower (1) and the main beam (4) of the long-span suspension bridge; S4: By arranging a plurality of longitudinal limit blocks (7) along the longitudinal direction of the bridge between the lower cross beams (9) of the two bridge towers (1) and the main beam (4) on the suspension bridge, the longitudinal limit blocks (7) generate a fourth constraint force under the most unfavorable load combination working condition of the suspension bridge to ultimately limit the longitudinal relative large deformation between the bridge towers (1) and the main beam (4) of the long-span suspension bridge, thereby reducing the scale of the beam end expansion device; S5: The longitudinal vibration-coordinated control constraint of the long-span suspension bridge is realized by the first constraint force generated by the temperature adaptive spring damper (6) under the low-speed action caused by temperature change, the second constraint force generated by the temperature adaptive spring damper (6) under the medium-speed action caused by automobiles and pulsating wind, the third constraint force generated by the temperature adaptive spring damper (6) under the fast action caused by earthquakes, and the fourth constraint force generated by the longitudinal limit block (7) under the most unfavorable load combination working condition.

4. The longitudinal vibration-joint control and restraint method for a long-span suspension bridge according to claim 3 is characterized in that: The step S1 of realizing the self-adaptation of the deformation of the main beam (4) under the temperature stress specifically includes: The three pistons of the temperature-adaptive spring damper (6) are respectively provided with flow holes. Under the low-speed action caused by temperature, the damping medium on the temperature-adaptive spring damper (6) flows freely through the flow holes. The temperature-adaptive spring damper (6) is longitudinally free and no additional constraint force is generated, that is, the first constraint force is zero. The damper does not generate temperature stress, thereby realizing the self-adaptation of the long-span suspension bridge to the temperature deformation of the main beam.

5. The longitudinal vibration-induced joint control and restraint method for a long-span suspension bridge according to claim 3 is characterized in that: The step S2 of suppressing the longitudinal low-frequency and low-amplitude reciprocating vibration of the beam end of the main beam (4) specifically includes: Springs are respectively provided on two adjacent pistons of the three pistons of the temperature-adaptive spring damper (6). When the suspension bridge is subjected to the medium-speed action caused by automobiles and pulsating wind, when relative deformation occurs between the bridge tower (1) and the main beam (4), the springs can provide spring force. At the same time, the pistons can provide constant damping force. The spring restraining force generated by the spring of the temperature-adaptive spring damper (6) and the constant damping force generated by the pistons together constitute a second restraining force to reduce the low-frequency and low-amplitude reciprocating vibration of the main beam (4).

6. The longitudinal vibration-induced joint control and restraint method for a long-span suspension bridge according to claim 3 is characterized in that: The step S3 of reducing the longitudinal relative large deformation between the bridge tower (1) and the main beam (4) of the long-span suspension bridge specifically includes: Damping valves are respectively provided on the two end covers and the piston at the middle position of the temperature-adaptive spring damper (6). Under the rapid action of an earthquake, the three pistons of the temperature-adaptive spring damper (6) respectively provide damping forces to form a third restraining force to reduce the large longitudinal deformation between the bridge tower (1) and the main beam (4).

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