Shock insulation structure of existing multi-layer reinforced concrete building

Abstract

The utility model discloses a shock insulation structure of an existing multi-layer reinforced concrete building, and relates to the technical field of existing building structure reinforcement. A seismic isolation structure of an existing multi-layer reinforced concrete building comprises an upper building structure, a foundation structure and a seismic isolation layer arranged between the upper building structure and the foundation structure. The seismic isolation layer comprises a seismic isolation layer beam plate, an upper buttress, a seismic isolation support and a lower buttress which are arranged in the direction from the upper building structure to the foundation structure. The shock insulation layer beam plate and the upper buttress are poured into an integrated structure through concrete. It can be understood that the shock insulation layer beam plate and the upper buttress are constructed and poured together, and the integrity and the anti-seismic property of the structure can be remarkably improved by pouring the shock insulation layer beam plate and the upper buttress into a whole.

Description

Technical Field

[0001] The utility model relates to the technical field of reinforcement of existing building structures, in particular to a seismic isolation structure of an existing multi-story reinforced concrete building. Background Art

[0002] At present, there are still a large area of ​​old houses in use in my country, which need to be reinforced. However, the traditional reinforcement method often requires the suspension of the normal use of the original building. During the traditional reinforcement process, all furniture and personnel in the building must be evacuated, otherwise it will affect the reinforcement work. In addition, traditional reinforcement will generate a lot of dust and noise. Since most of the buildings that need to be reinforced are located in prosperous areas, this will cause serious dust and noise pollution, seriously affecting the normal work and life of the surrounding residents. In addition, a considerable number of buildings that need to be reinforced originally had high-end interior decoration, and the pipelines and other equipment buried in the walls must be completely dismantled and scrapped, which not only causes a waste of resources, but also means huge economic losses. Utility Model Content

[0003] The main purpose of the utility model is to provide a seismic isolation structure for an existing multi-story reinforced concrete building, aiming to improve the reinforcement performance of the building without affecting the internal structure of the building.

[0004] To achieve the above-mentioned purpose, the utility model provides a seismic isolation structure of an existing multi-story reinforced concrete building, comprising an upper building structure and a foundation structure, and a seismic isolation layer arranged between the upper building structure and the foundation structure:

[0005] The seismic isolation layer includes a seismic isolation layer beam plate, an upper pier, a seismic isolation support, and a lower pier arranged along the direction from the upper building structure to the foundation structure. The seismic isolation layer beam plate and the upper pier are cast by concrete to form an integrated structure.

[0006] Optionally, the seismic isolation bearing is a lead rubber seismic isolation bearing.

[0007] Optionally, the ratio of the effective pressure-bearing area to the free surface area of ​​the seismic isolation bearing rubber pad is the first shape coefficient S1, and the ratio of the effective pressure-bearing body diameter of the rubber pad to the total thickness of the rubber is the second shape coefficient S2, satisfying the first shape coefficient S1≥15 and the second shape coefficient S2 is 3 to 6.

[0008] Optionally, the tensile bearing capacity of the seismic isolation bearing is not less than 1.5 MPa, and the tensile stress of the seismic isolation bearing is less than or equal to 1.0 MPa.

[0009] Optionally, the vertical ultimate bearing capacity of the seismic isolation bearing is greater than or equal to 90 MPa.

[0010] Optionally, the stiffness center of the seismic isolation layer overlaps with the mass center of the upper building structure.

[0011] Optionally, the setting heights of the seismic isolation supports in the seismic isolation layer are kept consistent.

[0012] Optionally, the cross-sectional area of ​​the upper pier is larger than the cross-sectional area of ​​the upper load-bearing rod of the upper building structure.

[0013] Optionally, the thickness of the upper pier is greater than the thickness of the seismic isolation layer beam slab.

[0014] Optionally, the cross-sectional area of ​​the lower pier is larger than the cross-sectional area of ​​the lower load-bearing rod of the foundation structure.

[0015] The seismic isolation structure of the existing multi-story reinforced concrete building of the present application includes an upper building structure and a foundation structure, and a seismic isolation layer arranged between the upper building structure and the foundation structure: the seismic isolation layer includes a seismic isolation layer beam slab, an upper pier, a seismic isolation support, and a lower pier arranged along the direction from the upper building structure to the foundation structure, and the seismic isolation layer beam slab and the upper pier are cast by concrete to form an integrated structure. It can be understood that the seismic isolation layer beam slab and the upper pier are constructed and cast together, and by casting the seismic isolation layer beam slab and the upper pier into one, the integrity and seismic resistance of the seismic isolation layer structure can be significantly improved. As an important component of the isolation layer, the isolation layer beams and slabs connect the upper and lower structures of the isolation layer to ensure the continuity and stability of the structure in the vertical direction. The isolation layer beams and slabs effectively transfer the upper vertical load to the lower structure through their horizontal conversion structure, achieving the overall coordination and balance of the structure, so that the building can maintain good integrity and anti-collapse ability under external loads such as earthquakes; at the same time, the isolation layer beam and slab structure provides necessary support for the upper building structure, so that the upper building structure can sit stably on the isolation layer, preventing the building structure from excessive deformation and damage during an earthquake.

[0016] At the same time, by setting up the isolation layer between the upper building structure and the foundation structure, the reinforcement method of the foundation isolation can be carried out without entering the house, that is, during the reinforcement process, the people in the upper building structure can live normally. The application of isolation technology makes it unnecessary to further reinforce the upper building structure or minimize the reinforcement work, thereby appropriately reducing costs and minimizing the impact of reinforcement on the normal use of the upper building structure. Moreover, on the basis of meeting the new earthquake fortification requirements of the building, this method can also achieve the purpose of green environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a schematic structural diagram of the reinforcement of an existing multi-story reinforced concrete structure with base isolation according to an embodiment of the utility model;

[0019] Figure 2 A three-dimensional model of a reinforced existing building according to an embodiment of the utility model;

[0020] Figure 3 This is a layout diagram of the seismic isolation support of an embodiment of the utility model;

[0021] Figure 4 This is a floor displacement result diagram obtained by numerical simulation calculation of seismic waves CHI-CHI waves under multiple earthquake conditions in one embodiment of the utility model;

[0022] Figure 5 This is a floor displacement result diagram obtained by numerical simulation calculation of seismic wave TH089 under frequent earthquake conditions in one embodiment of the utility model;

[0023] Figure 6 This is a floor displacement result diagram obtained by numerical simulation calculation of seismic wave RH1TG035 under frequent earthquake conditions in one embodiment of the utility model;

[0024] Figure 7 A floor shear force result diagram obtained by numerical simulation calculation of seismic waves CHI-CHI waves under multiple earthquake conditions in one embodiment of the utility model;

[0025] Figure 8 This is a floor shear force result diagram obtained by numerical simulation calculation of seismic wave TH089 under frequent earthquake conditions in one embodiment of the utility model;

[0026] Fig. 9 This is a floor shear force result diagram obtained by numerical simulation calculation of seismic wave RH1TG035 under frequent earthquake conditions in one embodiment of the utility model;

[0027] Fig.10 This is a top-level absolute acceleration result diagram obtained by numerical simulation calculation of seismic waves CHI-CHI waves under frequent earthquake conditions in one embodiment of the utility model;

[0028] Fig.11This is a top-level absolute acceleration result diagram obtained by numerical simulation calculation of seismic wave TH089 under frequent earthquake conditions in one embodiment of the utility model;

[0029] Fig.12 This is a graph of the top-layer absolute acceleration results obtained by numerical simulation calculation of the seismic wave RH1TG035 wave under frequent earthquake conditions in one embodiment of the utility model.

[0030] Description of Figure Numbers:

[0031] Label name Label name 10 Superstructure 40 Isolation bearing 20 Seismic isolation layer beam 50 lower buttress 30 upper buttress 51 Lower anchor 31 Upper anchor 53 Embedded plate 33 Support connecting plate 60 Infrastructure 70 Connecting bolts

[0032] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] Hereinafter, the sodium-rich sodium manganate sodium supplement and its preparation method, positive electrode material and battery of the present application are specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0035] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0037] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0038] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, a method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, a method may also include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0039] The main purpose of the utility model is to provide a seismic isolation structure for an existing multi-story reinforced concrete building, aiming to improve the reinforcement performance of the building without affecting the internal structure of the building.

[0040] To achieve the above-mentioned purpose, the utility model proposes a seismic isolation structure of an existing multi-story reinforced concrete building, which includes an upper building structure and a foundation structure, and a seismic isolation layer arranged between the upper building structure and the foundation structure: the seismic isolation layer includes seismic isolation layer beams and slabs, upper piers, seismic isolation bearings, and lower piers arranged along the direction from the upper building structure to the foundation structure, and the seismic isolation layer beams and slabs and the upper piers are cast by concrete to form an integrated structure.

[0041] It is understandable that the seismic isolation layer beams and slabs are constructed and cast together with the upper piers. By casting the seismic isolation layer beams and slabs together with the upper piers, the integrity and seismic resistance of the structure can be significantly improved. As an important component of the seismic isolation layer, the seismic isolation layer beams and slabs connect the upper structure and the lower structure of the seismic isolation layer to ensure the continuity and stability of the structure in the vertical direction. The seismic isolation layer beams and slabs effectively transfer the upper vertical load to the lower structure through its horizontal conversion structure, achieving the overall coordination and balance of the structure, so that the building can maintain good integrity and anti-collapse ability under external loads such as earthquakes; at the same time, the seismic isolation layer beam and slab structure provides necessary support for the upper building structure, so that the upper building structure can be stably located on the seismic isolation layer, preventing the building structure from being excessively deformed and damaged during an earthquake.

[0042] At the same time, by setting up the isolation layer between the upper building structure and the foundation structure, the reinforcement method of the foundation isolation can be carried out without entering the house, that is, during the reinforcement process, the people in the upper building structure can live normally. The application of isolation technology makes it unnecessary to further reinforce the upper building structure or minimize the reinforcement work, thereby appropriately reducing costs and minimizing the impact of reinforcement on the normal use of the upper building structure. Moreover, on the basis of meeting the new earthquake fortification requirements of the building, this method can also achieve the purpose of green environmental protection.

[0043] In one embodiment, the seismic isolation bearing is a lead rubber seismic isolation bearing.

[0044] It is understandable that the seismic isolation bearing, as the foundation of the seismic isolation device, must have sufficient bearing capacity to support the deadweight of the upper building structure. The shock-absorbing damper can effectively suppress excessive deformation of the bearing when an earthquake occurs, especially when the seismic force is in the horizontal direction. The seismic isolation bearing used in the utility model is a lead core rubber seismic isolation bearing.

[0045] In one embodiment, the ratio of the effective pressure-bearing area of ​​the rubber pad of the seismic isolation bearing to the free surface area is the first shape coefficient S1, and the ratio of the effective pressure-bearing body diameter of the rubber pad to the total thickness of the rubber is the second shape coefficient S2, satisfying the first shape coefficient S1≥15 and the second shape coefficient S2 is 3 to 6.

[0046] It is understandable that the shape of the rubber pad in the seismic isolation bearing has an important influence on the bearing capacity and deformation capacity of the bearing, and the shape is directly related to the geometric dimensions of the rubber pad and its proportional relationship. The performance of the seismic isolation bearing is mainly controlled by the first shape coefficient S1 and the second shape coefficient S2. Among them, the first shape coefficient S1 describes the proportional relationship between the effective pressure-bearing area of ​​the rubber layer in the rubber pad and its free surface area, while the second shape coefficient S2 reflects the proportional relationship between the effective pressure-bearing body diameter of the rubber pad and the total thickness of the rubber. By rationally designing and optimizing these shape coefficients, the performance of the seismic isolation bearing can be further improved.

[0047] First shape coefficient S1:

[0048]

[0049] Second shape coefficient S2:

[0050]

[0051] Where: d is the diameter of the effective pressure-bearing surface of the rubber layer; d0 is the diameter of the middle opening of the rubber layer; t0 is the thickness of each rubber layer; n is the total number of rubber layers;

[0052] The vertical stiffness and rotational stiffness of the rubber isolation bearing are closely related to the first shape coefficient S1, which reflects the degree of constraint of the steel plate on the deformation of the rubber layer. When the S1 value increases, the pressure on the rubber pad will also increase accordingly, resulting in an increase in the vertical stiffness. It is recommended that S1 ≥ 15. The yield load and horizontal stiffness of the rubber isolation bearing are related to the second shape coefficient S2, which represents the aspect ratio of the rubber pad when it is under pressure, that is, the compressive stability. The increase in S2 can make the rubber pad more stable, thereby improving its ability to withstand pressure. However, if S2 is too large, it will lead to an increase in the horizontal stiffness of the rubber pad and a decrease in the horizontal ultimate deformation capacity, which is not conducive to the energy dissipation and shock absorption effect of the isolation bearing. Therefore, the value of S2 should be moderate, and the recommended S2 is 3 to 6.

[0053] In one embodiment, the tensile bearing capacity of the seismic isolation bearing is not less than 1.5 MPa, and the tensile stress of the seismic isolation bearing is less than or equal to 1.0 MPa.

[0054] Tensile bearing capacity refers to the maximum tensile force that a structure or component can withstand without being damaged when subjected to tensile force. In engineering, this is an important concept because it is directly related to the safety and stability of the structure. The tensile bearing capacity of the seismic isolation bearing of the utility model should not be less than 1.5MPa.

[0055] Tensile stress refers to the internal force per unit area of ​​a material or component when it is subjected to tension. When an object is stretched, the distance between its internal molecules or atoms increases, thereby generating an internal force that resists stretching. The effect of this force is tensile stress. Under normal use, the support usually does not bear tensile stress. To ensure the safety and stability of the support, the tensile stress of the support should be controlled to be less than or equal to 1.0MPa. For different types of buildings, the value of the design compressive stress is based on the ratio of the code limit value to the safety factor.

[0056] In one embodiment, the vertical ultimate bearing capacity of the seismic isolation bearing is greater than or equal to 90 MPa.

[0057] In one embodiment, the seismic isolation layer beams, upper piers, lower piers, and seismic isolation supports disposed between the upper building structure and the foundation structure constitute a seismic isolation layer, and the stiffness center of the seismic isolation layer overlaps with the mass center of the upper building structure.

[0058] It is understandable that the eccentricity of the isolation layer is an important indicator for the calculation of the isolation structure, and the stiffness center of the isolation layer should overlap with the center of mass of the upper building structure as much as possible. When there is a large deviation between the center of stiffness and the center of mass, the influence of the torsion effect on the overall stability of the upper structure needs to be considered.

[0059] In one embodiment, the setting heights of the seismic isolation supports in the seismic isolation layer are kept consistent.

[0060] It is understandable that when arranging seismic isolation bearings, it is usually recommended to set them at a uniform height. Depending on specific needs, they can also be placed at different heights to accommodate various architectural and geological conditions.

[0061] In one embodiment, the cross-sectional area of ​​the upper pier is larger than the cross-sectional area of ​​the upper load-bearing rod of the upper building structure. It is understandable that the cross-sectional area of ​​the upper pier is larger than the cross-sectional area of ​​the upper load-bearing rod of the upper building structure, which can improve the safety, stability and durability of the seismic isolation layer structure.

[0062] In one embodiment, the thickness of the upper pier is greater than the thickness of the seismic isolation layer beam plate. It can be understood that the thickness of the upper pier is greater than the thickness of the seismic isolation layer beam plate, which can improve the stability, bearing capacity and durability of the seismic isolation layer structure.

[0063] In one embodiment, the cross-sectional area of ​​the lower pier is larger than the cross-sectional area of ​​the lower load-bearing rod of the foundation structure. It is understandable that the cross-sectional area of ​​the lower pier is larger than the cross-sectional area of ​​the lower load-bearing rod of the foundation structure, which can improve the stability, bearing capacity and durability of the seismic isolation layer structure.

[0064] It can be understood that, in one embodiment, the construction of the seismic isolation layer can be achieved according to the following steps: the first step: according to the design requirements of the seismic isolation reinforcement of the existing building and the structural characteristics of the selected seismic isolation bearing, determine the installation position of the seismic isolation bearing in the seismic isolation layer space of the existing building, and determine the specific structure of the upper pier and the lower pier; the second step: the construction of the seismic isolation layer beams and slabs and the reinforcement of the upper piers and the installation of the upper anchor rods, and the temporary support installation of the upper piers; the third step: the concrete pouring of the seismic isolation layer beams and slabs and the upper piers. After the concrete reaches the strength, the concrete columns within the installation height range of the seismic isolation bearings are removed, and the reinforcement of the lower piers is tied and the lower anchor rods are installed; the fourth step: the seismic isolation bearings are installed and related debugging is carried out, and the lower pier concrete is poured; the fifth step: the temporary support is removed, and the exposed metal parts of the seismic isolation layer are subjected to rust prevention treatment. The reinforcement method of the utility model takes "energy consumption" as the main means and adopts the "reinforcement while in use" non-entry reinforcement mode. The seismic isolation reinforcement reduces the seismic energy transmitted upward, and the upper structure can be reinforced as little as possible or does not need reinforcement to meet the requirements, which has good economic benefits. The reinforcement method of the utility model is of great significance to improving the seismic performance of existing building structures and achieving the goal of resilient cities.

[0065] Example

[0066] In order to make the technical solution and effects of the present invention more clear and explicit, the present invention is further described in detail through embodiments.

[0067] like Figure 1 As shown, this embodiment provides a method for reinforcing an existing multi-story reinforced concrete structure with base isolation. Figure 1 : is a structural schematic diagram of a seismic isolation layer, in which a seismic isolation layer is provided between an upper building structure 10 and a foundation structure 60, and the seismic isolation layer comprises an upper structure, a lower structure and seismic isolation bearings arranged on the upper structure and the lower structure. Specifically, the upper structure comprises a seismic isolation layer beam slab 20 arranged below the upper building structure 10, an upper pier 30 connected to the seismic isolation layer beam slab 20, and an upper anchor rod 31 embedded in the upper pier 30, and a bearing connecting plate 33 is further provided on the lower surface of the upper pier 30, and the bearing connecting plate 33 is connected to the upper anchor rod 31 by connecting bolts 70, the lower structure comprises a lower pier 50, a lower anchor rod 51 embedded in the lower pier 50, and an embedded plate 53 provided on the upper surface of the lower pier 50, and the embedded plate 53 is connected to the lower anchor rod 51 by connecting bolts 70, and the seismic isolation bearing 40 is connected between the upper pier 30 and the lower pier 50 through the bearing connecting plate 33 and the embedded plate 53.

[0068] The embodiment of the utility model is a five-story frame structure office building. Figure 2This is a three-dimensional model diagram for strengthening existing buildings. The building has a total of 5 floors, each with a floor height of 3.6m and a total height of 18m. The concrete strength of the beams and columns is C30, the cross-sectional dimensions of the main beam are: 300mm×600mm, the cross-sectional dimensions of the secondary beam are: 250mm×500mm; the cross-sectional dimensions of the columns are: 600mm×600mm, and the thickness of the cast-in-place concrete slab is: 100mm; the design service life of this project is 50 years, the seismic fortification category is Class C building, the building seismic fortification intensity is 7 degrees (0.1g), the fortification earthquake group is the first group, the site category is Class II, the maximum value of the horizontal earthquake influence coefficient is 0.08, and the site characteristic period is 0.35s; the corrected basic wind pressure is 0.75kN / m 2 , the ground roughness category is Class C. According to a method for reinforcing an existing multi-story reinforced concrete structure based on base isolation proposed by the utility model, the frame column (upper building structure) is separated from the foundation (foundation structure), and the upper building structure is separated from the foundation structure through jacking technology, and then an isolation support is added between the upper building structure and the foundation structure, and the isolation support reconnects the foundation and the frame column by connecting with the upper and lower piers. The upper and lower piers, the isolation layer beams and slabs, and the isolation supports constitute an isolation layer, which separates the upper building structure from the foundation structure.

[0069] This embodiment uses SAP2000 structural analysis software to compare the differences in performance parameters such as inter-layer shear force and inter-layer displacement before and after the overall frame reinforcement and transformation through nonlinear equation analysis and seismic elastoplastic analysis, so as to further verify the effectiveness of the seismic isolation reinforcement method proposed in this utility model. This embodiment uses SAP2000 structural design software to add upper and lower piers, seismic isolation layer beams and slabs, and seismic isolation bearings on the basis of the original structure, and establishes a seismic isolation structure model for calculation and analysis. The seismic isolation bearings, upper and lower piers, and seismic isolation layer beams and slabs are designed according to relevant specifications for concrete and seismic isolation bearings. The dimensions of the upper and lower piers are 900mm×900mm, and the dimensions of the seismic isolation layer beams and slabs are 300mm×700mm. The three-dimensional model of the seismic isolation structure is as follows: Figure 2 shown.

[0070] The arrangement of seismic isolation bearings has the following requirements:

[0071] (1) As an important indicator for calculating seismic isolation structures, the eccentricity of the seismic isolation layer should be as close as possible to the center of mass of the upper building structure. When there is a large deviation between the center of mass and the center of rigidity, the influence of the torsional effect on the overall stability of the upper structure needs to be considered.

[0072] (2) To ensure the effectiveness of the seismic isolation device, its bottom layout should correspond to the horizontal layout of the vertical load-bearing members of the upper building and the lower foundation. In other words, when arranging the seismic isolation device, it is necessary to ensure that the position of the seismic isolation support corresponds to the horizontal position of the main load-bearing members (such as columns, walls, etc.) that bear the vertical load in the upper building structure and the lower foundation structure, and effectively connect the upper building structure and the foundation. The layout position of the seismic isolation device should be determined according to the specific design requirements and building characteristics to ensure that the horizontal stiffness center of the seismic isolation layer is basically consistent with the center of mass of the upper structure.

[0073] (3) When arranging seismic isolation bearings, it is usually recommended to set them at a uniform height. Depending on specific needs, they can also be placed at different heights to adapt to various architectural and geological conditions.

[0074] According to the above-mentioned relevant provisions, and taking into full consideration the specific structural characteristics and actual conditions of this embodiment, the use of the base isolation bearing of the existing frame structure is shown in Table 1 and the specific arrangement scheme is shown in Figure 3 shown.

[0075] Table 1 Use of seismic isolation bearings

[0076]

[0077] The comparison of the periods of the seismic isolation structure and the non-seismic isolation structure under the design earthquake is shown in Table 2. After adopting the seismic isolation technology, the natural vibration period of the structure reinforced with base isolation is greatly improved.

[0078] Table 2 Structural periods before and after isolation

[0079] Mode shape Before isolation (s) After seismic isolation(s) 1 0.75 2.47 2 0.73 2.46 3 0.66 2.13

[0080] The dynamic response of a structure to earthquakes is not only deeply affected by the dynamic characteristics of the structure itself, but is also closely related to the spectrum, amplitude, and duration of the input seismic motion. Ground vibration has a wide frequency band and exhibits unstable random vibration characteristics. The calculation results obtained by selecting different seismic waves are also very different, so the seismic waves should be correctly selected when performing dynamic time-history analysis. According to the relevant content in the "Code for Seismic Design of Buildings", the seismic waves selected for dynamic time-history analysis of the structure must have spectral characteristics, effective peak values, and duration that conform to the building site category and earthquake grouping.

[0081] When conducting actual earthquake simulation, the waves selected in the seismic wave file cannot fully and truly reflect the fluctuations in the actual earthquake record. It is necessary to adjust the intensity, duration and spectrum of the seismic waves according to the actual situation and research needs. Through these adjustments, the seismic waves are closer to the characteristics of actual earthquakes, thereby improving the accuracy and reliability of the simulation.

[0082] (1) Earthquake amplitude adjustment

[0083] The acceleration value on the earthquake acceleration time history curve is scaled up or down according to the following formula to meet the required maximum earthquake acceleration response.

[0084]

[0085] Where: a′(t) is the adjusted amplitude; a(t) is the amplitude of the selected seismic wave record; A max is the required peak acceleration; A max is the peak acceleration of the selected seismic wave;

[0086] (2) Earthquake duration

[0087] The effective duration of the input earthquake acceleration time history curve is usually calculated from the point where the curve first reaches 10% of its maximum peak value until the last point also reaches 10% of the maximum peak value. It takes a certain amount of time for the structure to enter the nonlinear stage and accumulate damage. It is necessary to ensure that the selected earthquake duration is sufficient to ensure that the structural vibration reaches a stable stage. Generally, 5 to 10 times the basic period of the structure is selected as the effective duration of the earthquake.

[0088] (3) Earthquake spectrum adjustment

[0089] Considering the effect of regional limits on ground motion during earthquakes, it is necessary to ensure that the dominant period and shape of the determined real earthquake response spectrum are as consistent as possible with the corresponding spectrum characteristics of the region. If there is a difference between the two, it is necessary to adjust the duration of the real earthquake data, keep the acceleration value unchanged, and change its dominant period by lengthening or shortening the time axis of the retained data, so as to more accurately reflect the earthquake characteristics of the region.

[0090] This embodiment uses the modal method to perform elastic time history analysis on the frame model under multiple earthquake conditions. The model is initially in a stress-free state and the modal damping is 0.05. The simulation only considers the action of unidirectional seismic waves, so only the X direction is input for calculation and solution. The three selected seismic waves are input under multiple earthquake conditions to compare and analyze the differences in inter-layer displacement, floor shear, and top floor absolute acceleration before and after seismic isolation reinforcement.

[0091] Under the condition of multiple earthquakes, three seismic waves are input, and the results of floor displacement, floor shear force, and top floor absolute acceleration calculated by numerical simulation are as follows: Figures 4 to 12 As shown. After the existing building is seismically isolated and reinforced, the main displacement of the structure occurs in the isolation layer, and the displacement between the upper structure layers changes relatively smoothly. The maximum inter-layer displacement results of the structure are shown in Table 3. When the existing frame structure is reinforced with base isolation, due to the performance characteristics of the isolation bearing, the isolation layer is flexible, and the upper structure is a whole. When an earthquake occurs, the upper structure mainly moves relative to the ground as a whole, and the inter-layer displacement is greatly reduced.

[0092] As the floors rise, the inter-layer shear force of the structure gradually decreases. The existing frame structure is reinforced by base isolation, which greatly reduces the shear force of the floors compared to the unreinforced structure. The maximum shear force of the bottom layer of the structure is shown in Table 4. The isolation reinforcement method separates the upper building structure from the foundation structure. When an earthquake occurs, the shear force generated at the bottom of the structure is consumed by the support, which greatly reduces the impact of the earthquake on the upper building structure. Therefore, the existing frame structure is reinforced by base isolation, and the shear force on the structure is greatly reduced compared to the traditional earthquake-resistant reinforcement method.

[0093] The maximum absolute acceleration of the top floor is shown in Table 5. Compared with the unreinforced structure, the absolute acceleration of the top floor is greatly reduced after seismic isolation reinforcement. The use of seismic isolation reinforcement can dissipate earthquake energy to a great extent.

[0094] Table 3 Maximum inter-story displacement

[0095]

[0096] Table 4 Maximum shear force value of bottom layer

[0097]

[0098] Table 5 Maximum absolute acceleration of the top layer

[0099] seismic waves <![CDATA[Unreinforced (mm / s 2 )]]> <![CDATA[After reinforcement (mm / s 2 )]]> CHI-CHI wave 1982.08 673.29 TH089 wave 2424.52 1128.69 RH1TG035 wave 1899.00 816.68

[0100] This embodiment uses the direct integration method to perform an elastoplastic time-history analysis of the frame model under rare earthquake conditions. This embodiment demonstrates the reinforcement effect of the seismic isolation structure of an existing multi-story reinforced concrete building proposed in the utility model on an existing frame, and the maximum inter-story displacement, the maximum shear force value of the bottom layer, and the maximum absolute acceleration value of the top layer are shown in Tables 6 to 8. Compared with frequent earthquake conditions, the existing frame structure adopts the seismic isolation structure of an existing multi-story reinforced concrete building proposed in the utility model, and the maximum inter-story displacement shown in the case of a rare earthquake is more significantly improved, indicating that the existing building reinforced with foundation isolation has higher safety.

[0101] Table 6 Maximum inter-story drift

[0102] seismic waves <![CDATA[Unreinforced (mm / s 2 )]]> <![CDATA[After reinforcement (mm / s 2 )]]> CHI-CHI wave 1982.08 673.29 TH089 wave 2424.52 1128.69 RH1TG035 wave 1899.00 816.68

[0103] Table 7 Maximum shear force value of bottom layer

[0104] seismic waves Unreinforced (kN) After reinforcement(kN) CHI-CHI wave 6850 3614 TH089 wave 5186 2958 RH1TG035 wave 6597 4722

[0105] Table 8 Maximum absolute acceleration of the top layer

[0106] seismic waves <![CDATA[Unreinforced (mm / s 2 )]]> <![CDATA[After reinforcement (mm / s 2 ) <!-- 9 -->]]> CHI-CHI wave 5766.30 4066.26 TH089 wave 4862.78 4272.61 RH1TG035 wave 5300.22 3560.88

[0107] The utility model aims to solve the deficiencies in existing building reinforcement technology and provide a seismic isolation structure for existing multi-story reinforced concrete buildings. The structure adopts "energy dissipation" as the main means to effectively reduce the upward transmission of seismic energy, so that the upper structure can meet the seismic requirements with the maximum reduction or without further reinforcement, and has significant economic benefits.

[0108] The above are only exemplary embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A seismic isolation structure of an existing multi-story reinforced concrete building, characterized in that: The invention comprises a superstructure and a foundation structure, and a seismic isolation layer arranged between the superstructure and the foundation structure: The seismic isolation layer includes a seismic isolation layer beam plate, an upper pier, a seismic isolation support, and a lower pier arranged along the direction from the upper building structure to the foundation structure. The seismic isolation layer beam plate and the upper pier are cast by concrete to form an integrated structure.

2. The seismic isolation structure of an existing multi-story reinforced concrete building as claimed in claim 1, characterized in that: The seismic isolation bearing is a lead core rubber seismic isolation bearing.

3. The seismic isolation structure of an existing multi-story reinforced concrete building as claimed in claim 2, characterized in that: The ratio of the effective pressure-bearing area to the free surface area of ​​the seismic isolation bearing rubber pad is the first shape coefficient S1, and the ratio of the effective pressure-bearing body diameter of the rubber pad to the total thickness of the rubber is the second shape coefficient S2. The first shape coefficient S1≥15 and the second shape coefficient S2 is 3 to 6.

4. The seismic isolation structure of an existing multi-story reinforced concrete building as claimed in claim 2, characterized in that: The tensile bearing capacity of the seismic isolation bearing is not less than 1.5 MPa, and the tensile stress of the seismic isolation bearing is less than or equal to 1.0 MPa.

5. The seismic isolation structure of an existing multi-story reinforced concrete building as claimed in claim 2, characterized in that: The vertical ultimate bearing capacity of the seismic isolation bearing is greater than or equal to 90 MPa.

6. The seismic isolation structure of an existing multi-story reinforced concrete building according to any one of claims 1 to 5, characterized in that: The stiffness center of the seismic isolation layer overlaps with the mass center of the upper building structure.

7. The seismic isolation structure of an existing multi-story reinforced concrete building according to any one of claims 1 to 5, characterized in that: The setting heights of the seismic isolation supports in the seismic isolation layer are kept consistent.

8. The seismic isolation structure of an existing multi-story reinforced concrete building according to any one of claims 1 to 5, characterized in that: The cross-sectional area of ​​the upper pier is larger than the cross-sectional area of ​​the upper load-bearing rod of the upper building structure.

9. The seismic isolation structure of an existing multi-story reinforced concrete building according to any one of claims 1 to 5, characterized in that: The thickness of the upper pier is greater than the thickness of the seismic isolation layer beam plate.

10. The seismic isolation structure of an existing multi-story reinforced concrete building according to any one of claims 1 to 5, characterized in that: The cross-sectional area of ​​the lower pier is larger than the cross-sectional area of ​​the lower load-bearing rod of the foundation structure.

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