CN105297617B - Double-column type swinging shock-insulation bridge pier structure system - Google Patents

Abstract

The utility model relates to a double-column rocking seismic-isolation pier structure system, which belongs to the field of bridge engineering. The structural system is mainly composed of superstructure, reinforced concrete pier sections and concrete-filled steel pipe pier sections, caps, concrete-filled steel pipe pins, unbonded prestressed steel bars, and the like. Concrete-filled steel pipe pier segments and caps, reinforced concrete pier segments and the superstructure are connected by unbonded prestressed steel bars, supplemented by external energy dissipators and metal rings, which can effectively provide bridge structure shock absorption and isolation and self-resetting ability. The stress mechanism of the structural system designed by the present invention is clear, which can reduce the seismic action of the structure under the premise of ensuring that the structural system has sufficient strength and rigidity, and provide effective energy dissipation capacity and self-resetting capacity, which can solve the traditional double-column pier structure Replacement of bearings within the life cycle of the system, serious damage and large residual deformation after earthquake action.

Description

Structural system of double-column rocking seismically isolated pier

technical field

The invention belongs to the field of bridge engineering. In particular, it relates to a double-column rocking seismic-isolation pier structure system that uses unbonded prestressing technology and energy-dissipating components to control the seismic response and residual deformation of the structure.

Background technique

my country is located between the circum-Pacific seismic belt and the Eurasian seismic belt. Most of the country is an earthquake zone, especially the western part of my country is mostly a strong earthquake zone with frequent seismic activities. The bridge is a pivotal project of the traffic lifeline, and its construction cost is high. Once it is damaged by an earthquake, it will cause huge economic losses, and it is extremely difficult to repair after the earthquake. The number of casualties directly on the bridge was not many, but the economic losses and casualties caused by the damage and interruption of traffic lifelines were immeasurable, resulting in rescue personnel not being in place in time, and many people were exacerbated by the earthquake disaster because they did not receive timely rescue. At the same time, it is difficult to repair the damaged large bridges, which seriously affects the production and life in the disaster area and the post-disaster reconstruction work.

At present, the seismic design method of bridges is mainly developed around the concept of ductility, that is, the reinforced concrete piers are designed as ductile components, and the difference in strength and safety level is formed with the important capacity protection components. The aseismic mechanism of ductile pier components is to select a suitable plastic hinge area, use the elastic-plastic deformation of this area to dissipate the seismic energy, and prolong the basic period of the bridge structure, thereby reducing the seismic response of the bridge structure. The bridge structure with reasonable ductility and seismic design can prevent the bridge structure from collapsing during an earthquake and protect people's lives and properties. However, mid-short bridge piers are prone to bending-shear damage during earthquakes. In order to meet the demand for ductility and seismic resistance, a large number of stirrups and longitudinal steel bars need to be configured, which seriously increases the project investment cost. More importantly, the ductile anti-seismic design method will inevitably cause damage to the bridge pier, especially under the action of a strong earthquake, the damage to the plastic hinge area of the bridge pier will be very serious, and a large lateral residual displacement will occur, resulting in the substructure of the bridge after the earthquake. Partial reconstruction is required to provide transportation functions. It is even more difficult to estimate the indirect economic loss caused by traffic interruption caused by these demolition, replacement and repair work. The seismic isolation design method using seismic isolation bearings and damping devices can effectively solve the problems of the inevitable damage of ductile design bridge structures in earthquakes and the huge cost of post-earthquake repairs, and has been widely used in bridge structures in the past decade. The biggest disadvantage of the current seismic isolation method is that the structural displacement needs to be coordinated with the support system. Under the possible maximum seismic load, especially when the near-field seismic characteristics are relatively significant, the design displacement provided by the seismic isolation structure will be very large, which may cause the superstructure to break away from the support, and when the superstructure displacement exceeds the cover beam or the length of support provided by the abutment, beam drop occurs. Therefore, the bridge structure using shock-absorbing and isolating bearings may suffer serious damage to the bridge, or even drop beams and collapse under the action of rare earthquakes. At present, the commonly used seismic isolation bearings are laminated steel plate rubber bearings (lead rubber bearings, high damping rubber bearings, etc.), and their design service life is 50 years, while the design life of bridge engineering is generally 100 years. The performance and durability of roof steel plate and rubber are poor, and it is extremely difficult to replace the bearings. It is difficult to solve such problems with the existing bridge isolation bearings, so the cost of the whole life cycle of the bridge increases.

Contents of the invention

In order to overcome the above-mentioned defects, the present invention provides a double-column rocking seismic isolation pier structure system, which can reduce the seismic force on the structure under the premise of ensuring sufficient strength and rigidity, provide effective energy dissipation capacity and self-resetting ability, and avoid Severe damage and large residual deformation occurred in the structure to meet the high seismic requirements of the bridge structure.

The purpose of the present invention is to provide a double-column rocking earthquake-isolated pier structure system, which is characterized in that: the double-column rocking earthquake-isolated pier structure system is mainly composed of a bridge superstructure (1), a reinforced concrete pier segment (2) , cap (3), pile foundation (4), steel pipe concrete pier segment (5), external mild steel damper (6), unbonded prestressed steel bar (7), rubber cushion (12), bearing The steel backing plate (13) with hemispherical convex groove embedded in the platform, the steel pipe concrete pin (15), the shape memory alloy hollow cylinder (17) and the mild steel hollow cylinder (18) are composed of the bridge superstructure (1). There are two sections of reinforced concrete pier sections (2) side by side below, each section of reinforced concrete pier section (2) is a steel pipe concrete pier section (5), and below each section of steel pipe concrete pier section (5) is Cap (3), the following of each cap (3) are two pile foundations (4) side by side;

The bridge superstructure (1) and the reinforced concrete pier section (2) are connected through four parallel unbonded prestressed steel bars (7) inside the bridge superstructure (1) and the reinforced concrete pier section (2) Reserve a cylindrical hole through the steel cover (16) between the four parallel unbonded prestressed steel bars (7) at the bottom of the bridge superstructure (1), and place a steel pipe concrete pin (15) in the cylindrical hole, A shape memory alloy hollow cylinder (17) and a soft steel hollow cylinder (18) welded on the steel tube concrete pin (15) are arranged between the steel cover (16) and the steel tube concrete pin (15), and the shape memory The alloy hollow cylinder (17) and the mild steel hollow cylinder (18) are in an up-down relationship; the central axis of the shape memory alloy hollow cylinder (17) and the mild steel hollow cylinder (18) are connected with the steel pipe concrete pin The central axis of (15) is vertical; one end of the steel pipe concrete pin (15) is placed on the steel cover (16), the other end is located in the reinforced concrete pier section (2), and the steel pipe located inside the reinforced concrete pier section (2) The outer surface of the concrete pin (15) section is provided with a shear stud.

There is a space between the reinforced concrete pier segment (2) and the cap (3), and the reinforced concrete pier segment (2) and the cap (3) are connected by a steel tube concrete pier segment (5); the steel tube concrete pier segment ( The upper end of 5) is inserted into the reinforced concrete pier segment (2), and there are shear studs on the outer surface of the reinforced concrete pier segment (2), and there are steel flanges at the end; the upper surface of the cap (3) A round platform hole is provided, the upper top surface area of the round platform hole is greater than the lower bottom surface area, the bottom of the round platform hole is a steel backing plate (13) with hemispherical protrusions, and there are shears on the periphery of the steel backing plate (13) with hemispherical protrusions. The periphery of the steel backing plate (13) with strong studs and hemispherical protrusions is pre-buried in the cap (3); a layer of rubber cushion (12) is arranged on the side wall of the round platform hole; the steel pipe concrete pier segment (5) The lower end of the steel pipe concrete pier section (5) is located in the hole of the round platform, and the lower end port of the steel pipe concrete pier section (5) is a steel plate with a groove, and the groove is fitted together with the hemispherical protrusion of the steel backing plate (13); (5) There are multiple independent external soft steel dampers between the outer reinforced concrete pier section (2) and the cap (3); the unbonded prestressed steel bar (7) runs through the reinforced concrete pier section (2 ), concrete-filled steel tube pier segments (5) and caps (3).

Furthermore, cross ribs (21) are welded inside the steel pipes in the concrete-filled steel pipe pier section (5), and the inside of the steel pipes is divided into four parts, each part of the inner surface of the steel pipes is provided with short ribs, and at the same time, the unbonded prestressed steel bars (7) are are distributed in four parts.

The upper part of the 1/3 length of the steel pipe concrete pier section (5) is poured in the reinforced concrete pier section (2).

The external mild steel damper (6) is composed of a mild steel inner core (23) and a high-strength metal outer casing (24), and the two ends of the mild steel inner core (23) are connected to the platform (3) and concrete-filled steel tube pier segments (5);

The unbonded prestressed steel bar (7) sequentially passes through the cap (3), the steel backing plate (13) with hemispherical convex groove, the steel pipe concrete pier section (5), the reinforced concrete pier section (2) , the concrete-filled steel tube pin bolt (15) and the bridge superstructure (1), the two ends are anchored on the bottom of the cap (3) and the bridge superstructure (1) by anchors (9) respectively.

Unbonded prestressed reinforcement has a self-resetting function.

The beneficial effects of the present invention are:

The structure system of the double-column rocking seismic-isolation bridge pier of the present invention has a significant seismic-reduction and isolation effect under the action of an earthquake, which is mainly reflected in the following points:

1. Since the pier-cap and pier-superstructure are only connected by unbonded prestressed steel bars, the contact parts can be lifted off. Therefore, the bending moment at the upper and lower ends of the pier can be effectively released during the earthquake, reducing the damage of the pier and reducing the The seismic force borne by the bridge structure dissipates the seismic energy through the swaying of the bridge piers, effectively controlling the response of the bridge piers in the earthquake.

2. The mild steel damper arranged on the top of the cap and the cross-section of the pier plays a role in dissipating the seismic energy, effectively controlling the development of plastic deformation of the pier, and concentrating the damage on the mild steel damper to protect the pier. And the mild steel damper is easier to replace after the earthquake.

3. The use of non-bonded prestressing technology and shape memory alloy rings provides the self-resetting ability of the bridge structure, effectively controls the residual deformation of the bridge pier, ensures the post-earthquake traffic service function of the bridge structure, and reduces post-earthquake repair work.

4. The present invention does not set a support between the pier and the superstructure, which can avoid the falling of the support and the excessive displacement of the main girder during the earthquake; at the same time, it also avoids the need for regular inspection and failure of the support due to durability problems The question of replacement.

5. The present invention has little modification to the design of existing conventional bridge piers, is easy to implement, has a wide range of applications, and can reduce the design cross-section and reinforcement consumption of bridge piers; the damage after the earthquake is concentrated in the mild steel damper, and it can be used after a little repair. Ensure uninterrupted traffic lifeline, reduce post-earthquake repair costs and reconstruction time in disaster areas. Therefore, the present invention has good social and economic benefits and is worthy of popularization and application.

Description of drawings

Figure 1 is an external schematic diagram of the structural system of the double-column swaying seismically isolated bridge pier.

Fig. 2 is a schematic cross-section A-A of the double-column swaying seismic-isolation pier structure system in Fig. 1 .

Fig. 3 is a B-B cross-sectional schematic diagram of the double-column swaying seismic-isolation pier structure system in Fig. 1 .

Fig. 4 is a D-D cross-sectional schematic diagram of the double-column rocking seismic-isolation pier structure system in Fig. 2 .

Fig. 5 is a schematic diagram of the F-F cross-section of the double-column swaying seismic-isolation pier structure system in Fig. 3 .

Figure 6 is a schematic diagram of the structure of the external mild steel damper of the double-column swaying seismic-isolation pier structure system.

1—bridge superstructure; 2—reinforced concrete pier section; 3—cap; 4—pile foundation; 5—steel tube concrete pier section; 6—external mild steel damper; 7—unbonded prestressed steel bar; 8—prestressed hole; 9—anchor; 10—shear stud; 11—steel flange; 12—rubber cushion; Backing plate; 15—steel tube concrete pin; 16—steel cover; 17—shape memory alloy hollow cylinder; 18—mild steel hollow cylinder; 19—cement mortar; 20—short rib; 21—cross rib; 22—anchor Rod; 23—mild steel inner core; 24—high-strength metal outer casing; 25—nut.

detailed description

The present invention separates the bottom of the pier from the cap and the upper structure from the top of the pier on the basis of the conventional reinforced concrete double-column pier, and only connects the unbonded prestressed steel strands with a metal damping device to realize the pier's stability. The rocking behavior dissipates the seismic energy and has a self-resetting function to achieve the purpose of shock absorption and isolation. The structure is mainly used in bridge engineering and river-crossing engineering seismic isolation technology with high seismic performance requirements.

As shown in Figures 1 to 6, the present invention is a double-column swaying earthquake-isolation pier structure system, which mainly includes a pier-capped connection structure and a pier-superstructure connection structure. Figure 2 and Figure 4 are schematic diagrams of the pier-cap connection structure of the double-column rocking seismic-isolation pier structure system, which mainly consists of reinforced concrete pier segment 2, cap 3, steel pipe concrete pier segment 5 and external mild steel damper 6 composition. The platform 3 reserves a circular platform hole whose upper top surface area is larger than the lower bottom surface. The bottom of the hole is placed with a steel backing plate 13 with a hemispherical convex groove embedded in the bottom of the hole. The steel backing plate 13 with a hemispherical convex groove The pre-embedded ends are welded with shear studs 10, and the side wall of the hole of the round table is arranged with a rubber cushion consistent with the size of the round table. The steel backing plate 13 with hemispherical convex groove is placed on the steel pipe concrete pier segment 5, and the bottom of the steel pipe concrete pier segment 5 is a steel plate with hemispherical groove, and the size of the groove is consistent with that of the convex groove. The upper part of 1/3 of the length of the concrete-filled steel pipe pier section 5 is poured in the reinforced concrete pier section 2, and the shear studs 10 are welded to the steel pipe of the steel pipe concrete pier section 5 along the length direction, and the end of the steel pipe is welded with a ring Steel flange11. The bearing platform 3 is connected with the concrete-filled steel pipe pier segment 5 through an external mild steel damper 6 and unbonded prestressed steel bars 7 . The external mild steel damper 6 is composed of a mild steel inner core 23 and a high-strength metal outer casing 24, and the two ends are connected to the cap 3 and the steel pipe concrete pier segment 5 through anchor rods 22. Figure 3 and Figure 5 are schematic diagrams of the pier-superstructure connection structure of the double-column rocking seismic-isolation pier structure system, which mainly consists of bridge superstructure 1, unbonded prestressed steel bars 7, rubber cushion 12, concrete filled steel pipe pins 15, The shape memory alloy hollow cylinder 17 and the mild steel hollow cylinder 18 are composed. The bridge superstructure 1 is isolated from the reinforced concrete pier segment 2 by a rubber cushion 12 and connected by an unbonded prestressed steel beam 7 . The upper structure 1 is provided with a steel cover 16, and a shape memory alloy hollow cylinder 17 and a mild steel hollow cylinder 18 are arranged between the steel cover 16 and the steel tube concrete pin 15 to provide energy dissipation and self-resetting functions. The steel pipe of the concrete filled steel pipe pin 15 is inserted into the steel pipe of the reinforced concrete section by welding the shear stud 10 and the steel flange 11 to enhance the connection strength. The unbonded prestressed steel bar 7 used in the bridge pier-cap connection structure and bridge pier-superstructure connection structure is a full-length steel bar, which passes through the cap platform 3, the steel backing plate with hemispherical convex groove 13, and the concrete filled steel pipe pier in sequence. Segment 5, reinforced concrete pier segment 2, steel tube concrete pin 15 and bridge superstructure 1 are anchored to the bottom of cap 3 and bridge superstructure 1 through anchorage 9. Figure 6 is a schematic diagram of the structure of the external mild steel damper of the double-column rocking seismic-isolation pier structure system, which consists of a mild steel inner core 23 and a high-strength metal outer sleeve 24, and the two ends connect the cap 3 and the steel pipe concrete pier through anchor rods 22 Section 5.

The present invention breaks through the traditional double-column bridge pier design idea, with flexible design and clear structural force, so that the double-column bridge pier structure system has good self-resetting performance and stable energy consumption capacity, and can be quickly replaced to meet the requirements of controlling residual deformation, vibration, etc. Post-quick update fixes and other requests. The external energy dissipator involved in the present invention is easy to replace, ensures the durability and post-earthquake repairability of the pier-column structure system, and is a breakthrough and development of the traditional pier-column joint system. The invention can well solve the problem that the traditional bridge piers have relatively large residual deformation after the earthquake load, and at the same time ensure sufficient energy dissipation capacity. In addition, the invention can replace the function of the support, so that the bridge structure does not use the support, which solves the problem that the traditional bridge needs to replace the support many times in the whole life cycle of the bridge, and greatly improves the economic benefit. The structural system of double-column rocking seismic-isolation piers has good performance under normal service loads and accidental earthquake loads, and is worthy of popularization and application in practical engineering.

Claims (5)

1. a kind of queen post waves shock insulation Bridge Pier Structure System, and its characteristic is：The queen post waves shock insulation bridge pier structure body Owner will be by bridge superstructure (1), reinforced concrete bridge pier sections (2), cushion cap (3), pile foundation (4), steel pipe encased concrete bridge Pier sections (5), external mild steel damper (6), no-cohesive prestressed reinforcement (7), rubber spacer (12), the pre- buried strap hemisphere of cushion cap are convex The billet (13) of groove, concrete filled steel tube pin (15), marmem hollow cylinder thing (17) and mild steel hollow cylinder Thing (18) is constituted, and has two sections of reinforced concrete bridge pier sections (2) side by side below bridge superstructure (1), and every section of reinforcing bar is mixed It is concrete pier of steel tube sections (5) below solidifying soil bridge pier sections (2), below every section of concrete pier of steel tube sections (5) It is two pile foundations (4) side by side below each cushion cap (3) for cushion cap (3)；

Lead to through bridge superstructure (1) and reinforced concrete between bridge superstructure (1) and reinforced concrete bridge pier sections (2) Four internal parallel no-cohesive prestressed reinforcement (7) connections of native bridge pier sections (2)；Bridge superstructure (1) bottom By the reserved cylindrical cavity of steel cage (16) between four parallel no-cohesive prestressed reinforcements (7), place in cylindrical cavity Concrete filled steel tube pin (15), is disposed between steel cage (16) and concrete filled steel tube pin (15) and is welded on concrete filled steel tube pin Marmem hollow cylinder thing (17) and mild steel hollow cylinder thing (18) on bolt (15), marmem hollow cylinder Thing (17) and mild steel hollow cylinder thing (18) are upper and lower relation；The central shaft and mild steel of marmem hollow cylinder thing (17) The central shaft of hollow cylinder thing (18) and the central axis of concrete filled steel tube pin (15)；Concrete filled steel tube pin (15) One end is placed on steel cage (16), and the other end is located in reinforced concrete bridge pier sections (2), positioned at reinforced concrete bridge pier sections (2) outer surface of internal concrete filled steel tube pin (15) section is provided with shearing peg；

Existential Space between reinforced concrete bridge pier sections (2) and cushion cap (3), reinforced concrete bridge pier sections (2) and cushion cap (3) Connected using concrete pier of steel tube sections (5)；The upper end insertion reinforced concrete bridge pier section of concrete pier of steel tube sections (5) Section (2), and the outer surface in this section of reinforced concrete bridge pier sections (2) has shearing peg, there is steel flange end；Cushion cap (3) Upper surface be provided with round platform hole, the upper top surface area of round platform hole is more than bottom surface area, and round platform hole bottom is band hemisphere The raised billet (13) of shape, the periphery of the billet with hemispherical projections (13) has shearing peg and the steel with hemispherical projections The periphery of backing plate (13) is embedded in cushion cap (3)；Round platform hole side wall cloth is equipped with one layer of rubber spacer (12)；Steel pipe encased concrete bridge The lower end of pier sections (5) be located at round platform hole in, concrete pier of steel tube sections (5) lower end port be with reeded steel plate, Groove fits together with the hemispherical projections of billet (13)；In the outer reinforced concrete bridge of concrete pier of steel tube sections (5) There are multiple independent external mild steel dampers between pier sections (2) and cushion cap (3)；No-cohesive prestressed reinforcement (7) is through steel Reinforced concrete bridge pier sections (2), concrete pier of steel tube sections (5) and cushion cap (3).

2. shock insulation Bridge Pier Structure System is waved according to a kind of queen post of claim 1, its characteristic is, concrete pier of steel tube Steel duct in sections (5) is welded with cross rib (21), and steel duct is divided into into four parts, and steel duct surface is every partly to be set There is short rib, while no-cohesive prestressed reinforcement (7) is distributed in four parts.

3. shock insulation Bridge Pier Structure System is waved according to a kind of queen post of claim 1, its characteristic is, concrete pier of steel tube The top of 1/3 length of sections (5) is cast in reinforced concrete bridge pier sections (2).

4. shock insulation Bridge Pier Structure System is waved according to a kind of queen post of claim 1, its characteristic is that the external mild steel hinders Buddhist nun's device (6) is made up of mild steel inner core (23) and high tensile metal trocar sheath (24), and mild steel inner core (23) two ends are connected by anchor pole (22) Connect cushion cap (3) and concrete pier of steel tube sections (5).

5. shock insulation Bridge Pier Structure System is waved according to a kind of queen post of claim 1, its characteristic is, prestressing without bondn steel Muscle (7) sequentially passes through cushion cap (3), the billet with hemispherical tongue (13), concrete pier of steel tube sections (5), reinforced concrete Native bridge pier sections (2), concrete filled steel tube pin (15) and bridge superstructure (1), two ends are anchored at respectively by anchorage (9) Above cushion cap (3) bottom and bridge superstructure (1).