CN111425039A - Micro-prestressed self-resetting wall with self-resetting variable friction damper and construction method thereof - Google Patents

Abstract

The invention discloses a micro-prestressed self-resetting wall provided with a self-resetting variable friction damper and a construction method thereof, comprising a foundation beam, a plurality of horizontal walls arranged on the foundation beam, and penetrating the several horizontal walls and the foundation beam The prestressed tendons that connect the two are provided with variable friction dampers between the several horizontal walls and between the horizontal walls and the foundation beams for connection and fixation; during construction, prestressed tendon channels are reserved on the foundation beams and set In the middle friction plate, an inner friction plate or a middle friction plate is arranged on the corresponding horizontal walls, and the horizontal walls and the foundation beams are connected and fixed, and the prestressed tendons are arranged to be slightly tensioned. Under the action of earthquake, the variable friction dampers arranged between the walls, between the walls and the foundation beams of the self-resetting wall can not only consume a large amount of ground vibration input energy through friction, but also realize the self-resetting of the variable friction dampers, combined with pre- The setting of stress tendons can further provide self-resetting force to eliminate the residual deformation of the wall.

Description

Micro-prestressed self-resetting wall with self-resetting variable friction damper and construction method thereof

technical field

The invention belongs to the field of civil engineering, in particular to a micro-prestressed self-resetting wall provided with a self-resetting variable friction damper and a construction method thereof.

Background technique

Earthquakes have brought huge economic losses and casualties to human beings. The traditional seismic design adopts the ductile design method, that is, under the action of earthquake, some parts of the structure are allowed to yield and fail, resulting in the expected form of structural failure, so as to ensure that the overall structure will not lose its function, and through the yielding of the components. Plastic deformation to dissipate most of the seismic energy, so as to achieve the purpose of ensuring the safety of the main structure. Although the traditional design method has certain reliability in avoiding the collapse of buildings and casualties, and can meet the seismic fortification goals of "not damaged in small earthquakes, repairable in moderate earthquakes, and not collapsed in large earthquakes", but in moderate earthquakes and large earthquakes, the traditional design method has certain reliability. In the post-earthquake repair work, the repair cost is often higher than the reconstruction cost, resulting in the failure of the seismic fortification target to be effectively achieved.

Self-reset wall is a structural form that provides lateral stiffness and self-reset capability to the structure by tensioning prestressed tendons, and dissipates seismic energy by installing various types of energy-dissipating components. The self-reset wall can effectively reduce the lateral displacement and residual deformation between layers of the structure.

However, the existing self-resetting prefabricated walls need to apply high prestress in order to improve the stiffness, self-resetting ability and shear bearing capacity. Excessive prestressing will reduce the ductility of the structure, and will not be able to play a beneficial role in earthquake resistance. As the initial prestressing increases, the loss of prestressing is inevitable. At the same time, the requirements for local compression of concrete are not easy to meet. .

SUMMARY OF THE INVENTION

Purpose of the invention: The first purpose of the present invention is to provide a micro-prestressed wall that can consume the energy under the action of earthquake and can realize complete self-reset;

The second object of the present invention is to provide a construction method for the above-mentioned micro-prestressed wall.

Technical scheme: The present invention is provided with a micro-prestressed self-resetting wall with self-resetting variable friction dampers, including a foundation beam, several horizontal walls arranged on the foundation beam, penetrating several horizontal walls and foundation beams and connecting the two. Connected prestressed tendons, variable friction dampers are arranged between the several horizontal walls and between the horizontal walls and the foundation beams for connection and fixation, the variable friction dampers include stacked or sleeved inner friction plates and middle friction plates , the outer friction plate is arranged on the outside of the middle friction plate, the contact surface between the middle friction plate and the outer friction plate is a zigzag undulating slope surface, and the inner friction plate and the middle friction plate are respectively arranged on several adjacent horizontal walls between the horizontal wall and the foundation beam respectively.

By combining the prestressed tendons and variable friction dampers in the wall, the invention can consume the energy under the earthquake action by combining the prestressing tendon and the variable friction damper in the wall, and eliminate or reduce the prefabricated reinforced concrete structure under the earthquake action. Residual deformation, while improving the shear resistance of the wall, significantly reduces the post-tensioning prestress, avoiding obvious plastic deformation of the main structural components such as prefabricated horizontal wall sections; at the same time, it can also achieve variable stiffness, taking into account the structure in earthquakes of different intensities. reaction below.

Furthermore, the inner friction plate, the middle friction plate, the outer friction plate and the horizontal wall of the device are connected and fixed by bolts, and the bolts located outside the outer friction plate are sleeved with disc springs. The middle friction plate is provided with reserved holes for the bolts where the middle friction plate and the inner friction plate and the outer friction plate slide relatively. Preferably, the middle friction plate can be H-shaped, the inner friction plate can be U-shaped, and the inner friction plate is sleeved in the middle friction plate.

Furthermore, the height of the inner friction plate and the outer friction plate of the variable friction damper is larger than the upper half of the middle friction plate, and the steel backing plate is set at the position where the inner friction plate and the outer friction plate are higher than the middle friction plate, and the three are fixed by bolts. connect.

Furthermore, in the present invention, shear keys are also provided between several horizontal walls and between the horizontal walls and the foundation beams for mortising.

The construction method of the above-mentioned micro-prestressed self-resetting wall of the present invention includes the following steps: reserving a prestressed rib channel on a foundation beam and setting a middle friction plate, and setting an inner friction plate or a middle friction plate on several corresponding horizontal walls, Connect and fix several horizontal walls and between horizontal walls and foundation beams, set up prestressed tendons and then slightly stretch them.

Beneficial effects: Compared with the prior art, the significant advantage of the present invention is: under the action of earthquake, the variable friction dampers arranged between the walls, between the walls and the foundation beams can not only consume a large amount of earthquakes through friction Dynamic input energy, and can realize the self-resetting of variable friction damper, and combined with the setting of prestressed tendons, can further provide self-resetting force to eliminate the residual deformation of the wall; The starting force and the allowable displacement are determined by the size of the bolt preload, the number and arrangement of the disc springs, the friction coefficient of the friction material, the size of the sawtooth slope, and the length of the screw hole groove. In addition, almost all components of the device can be processed off-site as required, and then transported to the construction site for assembly, and the entire assembly process is dry operation, effectively controlled labor cost, project progress and project quality.

Description of drawings

Fig. 1 is the structural representation of the self-resetting wall of the present invention;

Fig. 2 is the A-A sectional view of Fig. 1;

Fig. 3 is the structural schematic diagram of the variable friction damper of the present invention;

Fig. 4 is the structural schematic diagram of the outer friction plate of the variable friction damper and the reserved holes for the bolts of the present invention;

Fig. 5 is a schematic diagram of the structure of the reserved holes for the friction plate and bolts in the variable friction damper of the present invention;

Fig. 6 is the structural schematic diagram of the inner friction plate and the bolt reserved hole in the variable friction damper of the present invention;

Fig. 7 is the structural schematic diagram of the steel backing plate of the variable friction damper and the reserved holes for the bolts of the present invention;

8 is a schematic diagram of the variable friction damper of the present invention when it is in an initial position;

FIG. 9 is a schematic diagram of the variable friction damper of the present invention when it is pulled and slid.

Detailed ways

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings.

The micro-prestressed self-resetting wall of the invention is mainly used to improve the energy dissipation capacity of the prefabricated concrete wall under the action of earthquake, and under the condition of applying micro-stress, it can effectively eliminate or reduce the residual deformation of the structure under the action of earthquake , and improve the shear resistance of the wall and the assembly efficiency of the structure. As shown in FIG. 1 and FIG. 2 , specifically, the micro-prestressed self-resetting wall includes a prefabricated base beam 1 provided with shear keys 12 and several sections of prefabricated base beams 1 that include shear keys 12 . The main component composed of the concrete horizontal wall 2, and the connecting component composed of the completely self-resetting vertical variable friction damper 4 and the prestressed tendons 3, the vertical variable friction damper 4 is arranged on the two sides of the horizontal wall 2. side end. Several horizontal walls 2 and between the horizontal wall 2 and the foundation beam 1 are first mortised by the shear key 12, which improves the shear bearing capacity and effectively reduces the horizontal lateral displacement; at the same time, combined with the vertical variable friction damper 4, It can not only ensure that the residual displacement after the earthquake is small, the strength and stiffness decrease, but also avoid the reduction of structural ductility caused by the application of excessive prestress, simplify the construction process, facilitate post-disaster repair and quickly put into use, and can greatly reduce earthquakes. economic losses caused. In addition, each horizontal wall body 2 and the foundation beam 2 are reserved with passages for the prestressed tendons to pass through, and the prestressed tendons 3 are combined to apply pretension to assemble each horizontal wall body 2 and the foundation beam 1. The bonded prestressed tendons 3 not only play the role of assembling the wall in the installation stage, but also bear the bending moment and provide self-reset force in the use stage, and the prestressed tendons 3 of the horizontal wall 2 are close together after assembly, which is quite Since the prefabricated wall body 2 is pre-specified with a rotation point, the movement of the horizontal wall body 2 during the earthquake is a rigid body rotation around the rotation point, which effectively reduces or even eliminates the deformation of the horizontal wall body 2 itself. Therefore, the horizontal wall body 2 is basically kept in the elastic stage after the earthquake, thereby facilitating the reuse and reassembly of the components.

As shown in FIG. 3 , the vertical variable friction damper 4 includes an inner friction plate 5 and a middle friction plate 6 that are stacked or sleeved, preferably a sleeve type, the middle friction plate 6 can be H-shaped, and the inner friction plate 5 can be It is U-shaped, the inner friction plate 5 is sleeved in the middle friction plate 6, and the inner friction plate 5 and the middle friction plate 6 are respectively arranged between some adjacent horizontal walls 2 and respectively arranged in the horizontal wall 2 and the foundation beam 1 For example, the inner friction plate 5 is pre-buried in the upper horizontal wall 2 in the factory prefabrication stage, then the corresponding middle friction plate 6 is pre-buried in the adjacent lower horizontal wall 2 in the factory prefabrication stage, and is protected by shear resistance. The studs improve the co-working performance of the middle friction plate 6 and the prefabricated horizontal wall 2 . An outer friction plate 7 is provided on the outer side of the middle friction plate 6 . The inner friction plate 5 , the middle friction plate 6 , the outer friction plate 7 and the horizontal wall 2 are connected and fixed by friction type high-strength bolts 8 , that is, by pre-tightening the bolts 8 on the vertical variable friction damper 4 , each horizontal wall 2 is fixed. Between and between the horizontal wall 2 and the foundation beam 1, the bolts 8 are respectively sheathed with a plurality of disc springs 10 on the outer side of the outer friction plate 7 to fix it, and the disc springs 10 are preloaded to provide The initial friction force of the vertical variable friction damper 4 can be adjusted, and the starting force can be changed by adjusting the pre-tightening force of the variable friction damper 4 to adapt to different intensity areas. The contact surface of the middle friction plate 6 and the outer friction plate 7 is a serrated undulating slope surface, and the middle friction plate 7 is provided with a relative sliding between the middle friction plate 6 and the inner friction plate 5 and the outer friction plate 7. reserved holes for the bolts 9. The vertical variable friction damper 4 has a self-contained structure through the sawtooth slope structure between the outer friction plate 7 and the middle friction plate 6, the arrangement of the disc spring 10 and the gravity of the horizontal wall 2 above the variable friction damper 4. The reset performance reduces the requirement for the size of the prestressing force, so that only a small prestressing force is required to achieve the assembly of the prefabricated horizontal wall and the self-resetting performance. The height of the inner friction plate 5 and the outer friction plate 7 is greater than the upper half of the middle friction plate 6, and the inner friction plate 5 and the outer friction plate 7 are set higher than the middle friction plate 6 with steel backing plates 11, and the three are fixed by bolts 8 Connected, so that when there is relative movement with the middle friction plate 6, the two always work together without slippage.

In addition, as shown in FIGS. 4 to 7 , the inner friction plate 5 of the variable friction damper 4 is provided with six reserved holes 13 for circular bolts to pass through the bolts 8 , the upper part of the inner friction plate 5 and the upper part of the outer friction plate 7 There are two circular bolt reserved holes 13 at corresponding positions for passing through the bolt 8 . The middle friction plate 6 is provided with a rounded rectangular bolt reserved hole 9 at the position corresponding to the bolt 8 passing through, so as to reserve space for the bolt 8 when the middle friction plate 6 and the inner friction plate 5 and the outer friction plate 7 slide relative to each other. There are six reserved holes 13 for circular bolts on the outer friction plate 7 for passing through the bolts 8, and two reserved holes 13 for circular bolts are opened at the corresponding positions on the upper part of the outer friction plate 7 and the upper part of the inner friction plate 5 for passing through the bolts. over bolt 8. There are also two reserved holes 13 for circular bolts at corresponding positions on the steel backing plate 11 , through which the two bolts 8 are pre-tightened.

The construction method of the micro-prestressed self-resetting wall comprises the following steps: reserving a prestressed rib channel on a foundation beam (1) and setting a middle friction plate (6); The friction plate (5) or the middle friction plate (6) is used for connecting and fixing between several horizontal walls (2) and between the horizontal walls (2) and the foundation beam (1), and after setting the prestressing tendons (3), it is slightly tensioned .

Working principle: Under the action of earthquake, the prestressed tendons and the vertical variable friction dampers arranged at both ends of the wall can provide self-resetting force to eliminate the residual deformation of the wall. The friction consumes a lot of ground vibration input energy, and under the action of the sawtooth slope of the outer friction plate and the middle friction plate, the variable friction damper is self-resetting.

Specifically, as shown in Figures 8 and 9, when an earthquake occurs, one side of the precast concrete horizontal wall is in tension and the other side is compressed. When the seismic force reaches a certain magnitude, the gap between the walls on the tension side will stretch. Open, the entire horizontal wall rotates rigidly around the compression side, and the friction damper on the tension side slides. Due to the pre-tightening force applied to the disc spring, it is ensured that the sawtooth contact slope between the outer friction plate and the middle friction plate, and the contact surface between the middle friction plate and the inner friction plate generate initial friction, that is, the middle friction plate and the outer friction plate, the inner friction When the plate slips, the energy generated by the earthquake is dissipated by friction. When the middle friction plate and the outer friction plate slide along the slope, the disc spring is compressed, and a large normal pressure is generated on the outer friction plate, so that the teeth of the outer friction plate and the middle friction plate contact the slope, the middle friction plate and the The friction force of the contact surface of the inner friction plate increases, realizing the principle of variable friction energy consumption. After the earthquake, the horizontal wall returns to its initial position under the combined action of its own gravity, disc spring force and prestress, realizing self-reset and effectively reducing the residual displacement after the earthquake.

The mortise of the shear bond between the precast concrete horizontal walls and the bottom precast concrete horizontal soil wall and the precast foundation beams improves the shear bearing capacity, and the self-resetting force provided by the variable friction damper reduces the impact on the prestressing force. Therefore, the prestressed tendons only need a small amount of prestress to assemble the prefabricated wall and provide self-resetting force. However, when the seismic action is small, the horizontal walls will not be opened. When the seismic action exceeds a certain limit, the contact surface of the horizontal walls will be opened, and the friction energy of the variable friction damper will be dissipated, thereby avoiding prefabricated horizontal walls, etc. Damage to body components. After the earthquake, the whole wall is restored to its original position under the self-resetting force provided by the prestress, the gravity of the wall and the disc spring force in the variable friction damper.

Claims (8)

1. The utility model provides a little prestressing force is from restoring to throne wall with become friction damper from restoring to throne which characterized in that: the novel foundation beam comprises a foundation beam (1), a plurality of horizontal walls (2) arranged on the foundation beam (1), and prestressed ribs (3) which penetrate through the horizontal walls (2) and the foundation beam (1) and are connected with the horizontal walls (2) and the foundation beam (1), wherein variable friction dampers (4) are arranged between the horizontal walls (2) and the foundation beam (1) for connection and fixation, each variable friction damper (4) comprises an inner friction plate (5) and an outer friction plate (6) which are stacked or sleeved, the outer friction plate (7) arranged on the outer side of the middle friction plate (6), the contact surfaces of the middle friction plate (6) and the outer friction plate (7) are sawtooth-shaped and fluctuant surfaces which are embedded, and the inner friction plate (5) and the middle friction plate (6) are respectively arranged between the adjacent horizontal walls (2) and are respectively arranged between the horizontal walls (2) and the foundation beam (1).

2. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 1, characterized in that: the inner friction plate (5), the middle friction plate (6), the outer friction plate (7) and the horizontal wall body (2) are fixedly connected through bolts (8).

3. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 1, characterized in that: and a bolt reserved hole channel (9) for the relative sliding of the middle friction plate (6), the inner friction plate (5) and the outer friction plate (7) is formed in the middle friction plate (6).

4. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 2, characterized in that: and a disc spring (10) is sleeved on the bolt (8) and positioned outside the outer friction plate (7).

5. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 1, characterized in that: the middle friction plate (6) is H-shaped, the inner friction plate (5) is U-shaped, and the inner friction plate (5) is sleeved in the middle friction plate (6).

6. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 5, characterized in that: the height of the inner friction plate (5) and the outer friction plate (7) is larger than the upper half part of the middle friction plate (6), and a steel backing plate (11) is arranged at the position, higher than the middle friction plate (6), of the inner friction plate (5) and the outer friction plate (7), and the inner friction plate, the middle friction plate and the outer friction plate are fixedly connected through a bolt (8).

7. The micro-prestressed self-resetting wall provided with the self-resetting variable-friction damper according to claim 1, characterized in that: shear keys (12) are arranged among the horizontal walls (2) and between the horizontal walls (2) and the foundation beam (1) for joggling.

8. The construction method of the micro-prestressed self-restoring wall as set forth in claim 1, characterized by comprising the steps of: the prestressed rib channel is reserved on the foundation beam (1), the middle friction plate (6) is arranged, the inner friction plates (5) or the middle friction plates (6) are arranged on the corresponding horizontal walls (2), the horizontal walls (2) and the foundation beam (1) are fixedly connected, and the prestressed ribs (3) are arranged and then are tensioned slightly.

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