A milling slip shock-absorbing precast staircase

Abstract

The present invention provides a grinding and sliding shock-absorbing precast staircase, which includes a precast stair slab, a fixed platform and a sliding platform. One end of the precast stair slab is connected to the fixed platform through a fixed hinge mechanism, and the other end is connected to the sliding platform through a grinding and sliding guiding and resetting mechanism. The present invention has the advantages of simple structure, clear mechanism, and convenient construction, and is applicable to the staircase units in the frame structure and the frame part of the frame-shear structure. It is especially applicable to the staircase units in which the intermediate landing is separated from the main frame. By changing the support mode of the movable hinge support of the precast stair slab to the sliding shock-absorbing support mode, the problems of jumping vibration and excessive horizontal displacement of the stair slab in the existing separated connection technology applied to prefabricated buildings are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and particularly relates to a grinding and sliding shock-absorbing precast staircase. Background Art

[0002] Staircases serve as vertical traffic channels in multi-story and high-rise buildings and are also important escape routes during earthquakes. However, in previous earthquakes, especially the Wenchuan earthquake, the stairwells suffered severe damage. The investigation and analysis of the earthquake damage showed that due to the integral casting connection method between the staircase components and the main structure, the stair slab formed a diagonal bracing effect and participated in the lateral force resistance of the structure, resulting in complex forces at the stairwell position. During earthquakes, the stairwell often absorbed more energy and was damaged first, forming the first seismic defense line and failing to achieve the aforementioned expected earthquake relief function.

[0003] To solve the seismic problem of stairwells in frame structures, the current seismic design codes and related atlases propose the separated connection technology for the stair slab, that is, using a sliding connection structure to release the connection constraints between the staircase and the main structure can effectively reduce the diagonal bracing effect. Since prefabricated buildings have the property of prefabrication first and then connection, and the core principle of this technology is to change resistance to release, the application of this technology can be preferentially considered in the frame stairwells of prefabricated buildings. However, research has shown that the current separated connection technology for the stair slab mainly disconnects the staircase from the main structure simply, and the stair slab will produce severe jumping phenomena under earthquake action, seriously weakening the seismic performance of prefabricated buildings. Another research proposed that to further reduce the influence of the stairwell structure on the seismic performance of the main structure, measures such as separating the intermediate landing from the main structure can be taken. For example, the four-column support scheme can effectively reduce the vibration coupling effect between the stairwell structure and the main structure, but under rare earthquakes, the stairwell structure will produce large horizontal displacements, and problems such as free displacement constraints, plastic deformation concentration, and node connection failure will occur when the precast stair slab adopts the support method. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes a grinding and sliding shock-absorbing precast staircase.

[0005] A grinding and sliding shock-absorbing precast staircase proposed by the present invention includes a precast stair slab, a fixed platform, and a sliding platform. One end of the precast stair slab is connected to the fixed platform through a fixed hinge mechanism, and the other end is connected to the sliding platform through a grinding and sliding guiding and resetting mechanism.

[0006] Preferably, the fixed hinge mechanism includes a plurality of fixed sleeves and a plurality of fixed pins. The plurality of fixed sleeves are arranged in a straight line side by side and are embedded in the fixed platform, and the bottom ends of the plurality of fixed pins are respectively connected to the plurality of fixed sleeves, and the top ends of the plurality of fixed pins are all connected to the end of the precast stair slab.

[0007] Preferably, a plurality of first reserved holes arranged side by side in a straight line are formed at the end of the precast ladder slab. The plurality of first reserved holes are respectively arranged corresponding to a plurality of fixing pins, and the fixing pins are inserted into the corresponding first reserved holes. The first reserved holes are filled with grout mortar to fix the fixing pins.

[0008] Preferably, a gap is left between the bottom surface of the precast ladder slab and the top surface of the fixed platform to form a first horizontal joint, and a gap is left between the side surface of the precast ladder slab and the side surface of the fixed platform to form a first vertical joint.

[0009] Preferably, a fixing member is formed by filling cement mortar in the first horizontal joint, and a connecting member is formed by filling flexible material in the first vertical joint.

[0010] Preferably, the grinding slip guiding and resetting mechanism includes a plurality of slip sleeves and a plurality of slip pins; the plurality of slip sleeves are arranged side by side in a straight line and the plurality of slip sleeves are embedded in the slip platform; a plurality of grooves are formed on the bottom surface of the precast ladder slab to form a rough surface. A gap is left between the rough surface and the top surface of the slip platform to form a second horizontal joint, and a grinding member is formed by filling medium-fine ceramsite concrete in the second horizontal joint. A plurality of second reserved holes arranged side by side in a straight line and communicating with the second horizontal joint are formed at the end of the precast ladder slab. The plurality of second reserved holes are respectively arranged corresponding to the plurality of slip sleeves; the bottom ends of the plurality of slip pins are respectively connected to the plurality of slip sleeves, and the top ends of the plurality of fixing pins are respectively inserted into the plurality of second reserved holes. The second reserved holes are filled with grouting sand grains.

[0011] Preferably, a gap is left between the side surface of the precast ladder slab and the side surface of the slip platform to form a second vertical joint, and a guiding and resetting member connecting the precast ladder slab and the slip platform is arranged in the second vertical joint.

[0012] Preferably, a plurality of sealing holes are further formed at the end of the precast ladder slab. The plurality of sealing holes communicate with the plurality of second reserved holes respectively, and sealing members are formed by filling medium-fine ceramsite concrete in the sealing holes.

[0013] Preferably, a backing plate is arranged at one end of the sealing hole close to the second reserved hole. The backing plate is provided with an oblong hole, and the slip pin passes through the oblong hole and is connected to a nut.

[0014] A milling-sliding shock-absorbing precast staircase proposed by the present invention, one end of the precast slab is connected to the fixed platform through a fixed hinge mechanism and the other end is connected to the sliding platform through a milling-sliding guiding and resetting mechanism. The milling-sliding guiding and resetting mechanism has functions such as elastic positioning, milling-sliding, guiding and resetting. Under frequent earthquakes, the milling-sliding guiding and resetting mechanism can limit the precast slab within the elastic deformation range, achieving the performance goal of "no damage under minor earthquakes"; under fortification earthquakes and rare earthquakes, the milling-sliding guiding and resetting mechanism and the separated rest platform jointly act to decouple the vibration of the staircase substructure and the main structure. At this time, relative movement occurs between the precast slab and the sliding platform due to the plastic deformation of the structure, and then functions such as milling energy dissipation, sliding seismic isolation and post-earthquake resetting are exerted, which can not only prevent the staircase from becoming the first seismic defense line, but also significantly improve the seismic performance of the structure. The present invention has the advantages of simple structure, clear mechanism, and convenient construction, and is applicable to the staircase units of frame structures and the frame part of frame-shear structures, especially applicable to the staircase units with the separated connection between the intermediate rest platform and the main frame. By changing the support method of the movable hinge support of the precast slab to the support method of the sliding shock-absorbing support, the problems such as jumping vibration and excessive horizontal displacement of the slab existing in the application of the existing separated connection technology to prefabricated buildings are effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural schematic diagram of a milling-sliding shock-absorbing precast staircase proposed by the present invention;

[0016] Figure 2 is Figure 1 the enlarged structural schematic diagram at A in

[0017] Figure 3 is Figure 1 the enlarged structural schematic diagram at B in

[0018] Figure 4 is a structural schematic diagram of the precast slab in a milling-sliding shock-absorbing precast staircase proposed by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Referring to Figures 1 - 4 , the present invention proposes a milling-sliding shock-absorbing precast staircase, which includes a precast slab 1, a fixed platform 2 and a sliding platform 3. One end of the precast slab 1 is connected to the fixed platform 2 through a fixed hinge mechanism and the other end is connected to the sliding platform 3 through a milling-sliding guiding and resetting mechanism.

[0020] In the present invention, the precast ladder slab is connected to the sliding platform through the grinding sliding guiding and resetting mechanism, so that there is no relative displacement between the precast ladder slab 1 and the sliding platform 3 during the elastic deformation of the structure under frequent earthquakes, and relative movement occurs between the precast ladder slab 1 and the sliding platform 3 during the elastoplastic deformation of the structure under the fortification intensity earthquake and the rare earthquake. During the elastoplastic deformation of the structure under the fortification intensity earthquake and the rare earthquake, the precast ladder slab 1 and the sliding platform 3 reciprocate in a specified direction and return to the initial position after the earthquake.

[0021] In a specific embodiment, the fixed hinge mechanism includes a plurality of fixed sleeves 4 and a plurality of fixed pins 5. The plurality of fixed sleeves 4 are arranged side by side in a straight line and the plurality of fixed sleeves 4 are embedded in the fixed platform 2. A plurality of first reserved holes 6 arranged side by side in a straight line are formed at the end of the precast ladder slab 1. The first reserved holes 6 are circular holes, and the plurality of first reserved holes 6 are respectively arranged in one-to-one correspondence with the plurality of fixed pins 5. The bottom ends of the plurality of fixed pins 5 are respectively connected to the plurality of fixed sleeves 4, and the top ends of the plurality of fixed pins 5 are respectively inserted into the plurality of first reserved holes 6. The first reserved holes 6 are filled with grout mortar to fix the fixed pins 5, and the strength of the grout mortar is at least one grade higher than the material strength of the precast ladder slab 1.

[0022] In a specific embodiment, a gap is left between the bottom surface of the precast ladder slab 1 and the top surface of the fixed platform 2 to form a first horizontal joint 7, and a fixing member 9 is formed in the first horizontal joint 7 by filling cement mortar with a strength grade not lower than M15. A gap is left between the side surface of the precast ladder slab 1 and the side surface of the fixed platform 2 to form a first vertical joint 8, and a connecting member 10 is formed in the first vertical joint 8 by filling a flexible material.

[0023] In a specific embodiment, the grinding slip guiding and resetting mechanism includes a plurality of slip sleeves 11 and a plurality of slip pins 12. The plurality of slip sleeves 11 are arranged side by side in a straight line and the plurality of slip sleeves 11 are embedded in the slip platform 3. A plurality of grooves are formed on the bottom surface of the precast ladder slab 1 to form a rough surface 13. There is a gap between the rough surface 13 and the top surface of the slip platform 3 to form a second flat joint 14, and a grinding member 15 is formed by grouting with medium-fine ceramsite concrete in the second flat joint 14. The standard strength of the medium-fine ceramsite concrete grouting is not less than 10 MPa and is at least 2 grades lower than the material strength of the precast ladder slab 1. A plurality of second reserved holes 16 arranged side by side in a straight line and communicating with the second flat joint 14 are formed at the end of the precast ladder slab 1. The second reserved holes 16 are rectangular holes, and the plurality of second reserved holes 16 are respectively arranged in one-to-one correspondence with the plurality of slip sleeves 11. The bottom ends of the plurality of slip pins 12 are respectively connected to the plurality of slip sleeves 11, and the top ends of the plurality of fixing pins 5 are respectively inserted into the plurality of second reserved holes 16, and the second reserved holes 16 are filled with grouted sand grains 17. The rough surface 13 and the second flat joint 14 form a grinding surface to exert a grinding energy dissipation effect. Under an earthquake, the slip pins 12 slide, so that the grouted sand grains 17 enter the grinding surface to jointly exert a slip isolation effect with the grinding member 15. Through the mutual cooperation of the slip pins 12, the rough surface 13, the second flat joint 14 and the grinding member 15, it is realized that there is no relative displacement between the precast ladder slab 1 and the slip platform 3 during the elastic deformation of the structure under frequently-occurring earthquakes.

[0024] In a specific embodiment, there is a gap between the side surface of the precast ladder slab 1 and the side surface of the slip platform 3 to form a second vertical joint 18. A guiding and resetting member 19 for connecting the precast ladder slab 1 and the slip platform 3 is arranged in the second vertical joint 18. The guiding and resetting member 19 can be formed by filling a highly elastic material in the second vertical joint or can be a spring or a rubber plate. The second vertical joint 18 and the second reserved hole 16 jointly provide a sliding space for the slip pin 12. The sliding space is determined according to design calculations. Under an earthquake, after being compressed or stretched, the guiding and resetting member 19 can react on the precast ladder slab 1 to make it return to the initial state. Through the mutual cooperation of the second vertical joint 18, the resetting member 19, the slip pin 12, the rough surface 13, the grouted sand grains 17, the second flat joint 14 and the grinding member 15, it is realized that there is relative movement between the precast ladder slab 1 and the slip platform 3 during the elastic-plastic deformation of the structure under the fortification intensity earthquake and the rare earthquake.

[0025] In a specific embodiment, a plurality of sealing holes 20 are also formed at the end of the precast ladder slab 1. The sealing holes 20 are rectangular holes and the cross-sectional area of the sealing holes is larger than the cross-sectional area of the second reserved holes 16. The plurality of sealing holes 20 are respectively communicated with the plurality of second reserved holes 16, and sealing members 21 are formed by grouting with medium-fine ceramsite concrete in the sealing holes 20.

[0026] In a specific embodiment, a backing plate 22 is provided at one end of the hole plugging 20 close to the second reserved hole 16. The backing plate 22 is provided with an oblong hole. The sliding pin 12 passes through the oblong hole and is connected to a nut 23. The size of the oblong hole does not exceed the size of the second reserved hole 16. Under an earthquake, the nut 23 restricts the upper end of the sliding pin 12 and enables it to reciprocate in a fixed direction along the oblong hole of the backing plate 22. Through the mutual cooperation of the backing plate 22, the second vertical seam 18, the reset member 19 and the sliding pin 12, the connection structure realizes the reciprocating movement of the precast ladder plate 1 and the sliding platform 3 in the specified direction during the elastoplastic deformation of the structure under the fortification intensity earthquake and the rare earthquake and returns to the initial position after the earthquake.

[0027] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A grinding and sliding shock-absorbing precast staircase, characterized in that, It includes a precast ladder slab (1), a fixed platform (2) and a sliding platform (3). One end of the precast ladder slab (1) is connected to the fixed platform (2) through a fixed hinge mechanism, and the other end is connected to the sliding platform (3) through a grinding sliding guiding and resetting mechanism. The grinding sliding guiding and resetting mechanism includes a plurality of sliding sleeves (11) and a plurality of sliding pins (12). The plurality of sliding sleeves (11) are arranged side by side in a straight line and the plurality of sliding sleeves (11) are embedded in the sliding platform (3). A plurality of grooves are formed on the bottom surface of the precast ladder slab (1) to form a rough surface (13). There is a gap between the rough surface (13) and the top surface of the sliding platform (3) to form a second flat seam (14), and a grinding piece (15) is formed by grouting with medium and fine ceramsite concrete in the second flat seam (14). A plurality of second reserved holes (16) arranged side by side in a straight line and communicating with the second flat seam (14) are formed at the end of the precast ladder slab (1). The plurality of second reserved holes (16) are respectively arranged in one-to-one correspondence with the plurality of sliding sleeves (11). The bottom ends of the plurality of sliding pins (12) are respectively connected to the plurality of sliding sleeves (11), and the top ends of the plurality of fixing pins (5) are respectively inserted into the plurality of second reserved holes (16), and the second reserved holes (16) are filled with grouted sand grains (17). A plurality of sealing holes (20) are also formed at the end of the precast ladder slab (1). The plurality of sealing holes (20) communicate with the plurality of second reserved holes (16) respectively, and a sealing piece (21) is formed by grouting with medium and fine ceramsite concrete in the sealing holes (20). A backing plate (22) is arranged at one end of the sealing hole (20) close to the second reserved hole (16). The backing plate (22) is provided with an oblong hole, and the sliding pin (12) passes through the oblong hole and is connected to a nut (23).

2. The milling slip shock-absorbing precast staircase according to claim 1, characterized in that, The fixed hinge mechanism includes a plurality of fixed sleeves (4) and a plurality of fixed pins (5). The plurality of fixed sleeves (4) are arranged side by side in a straight line and the plurality of fixed sleeves (4) are embedded in the fixed platform (2). The bottom ends of the plurality of fixed pins (5) are respectively connected to the plurality of fixed sleeves (4), and the top ends of the plurality of fixed pins (5) are all connected to the end of the precast ladder slab (1).

3. The milling slip shock-absorbing precast staircase according to claim 2, wherein A plurality of first reserved holes (6) arranged side by side in a straight line are formed at the end of the precast ladder slab (1). The plurality of first reserved holes (6) are respectively arranged in one-to-one correspondence with the plurality of fixed pins (5), and the fixed pins (5) are inserted into the corresponding first reserved holes (6), and the first reserved holes (6) are filled with grouted mortar to fix the fixed pins (5).

4. The milling slip shock-absorbing precast staircase according to any one of claims 1-3, characterized in that, There is a gap between the bottom surface of the precast ladder slab (1) and the top surface of the fixed platform (2) to form a first flat seam (7), and there is a gap between the side surface of the precast ladder slab (1) and the side surface of the fixed platform (2) to form a first vertical seam (8).

5. The milling-slip shock-absorbing precast staircase according to claim 4, wherein, A fixing piece (9) is formed by filling cement mortar in the first flat seam (7), and a connecting piece (10) is formed by filling flexible material in the first vertical seam (8).

6. The milling slip shock-absorbing precast staircase according to claim 1, characterized in that, There is a gap between the side surface of the precast ladder slab (1) and the side surface of the sliding platform (3) to form a second vertical seam (18), and a guiding and resetting piece (19) connecting the precast ladder slab (1) and the sliding platform (3) is arranged in the second vertical seam (18).

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