A method of installing a liftable seismic isolation bearing

Abstract

The application discloses a kind of installation methods of liftable isolation bearing, method includes: positioning plate is embedded and fixed on lower structure component, make the center position of placing groove and notch plane satisfy predetermined coordinate and levelness requirement;The support body is hoisted to the above positioning plate, and under the guidance, shear key is inserted into placing groove, to complete the alignment of shear key and placing groove.The application is by the connecting bolt arranged between lower flange plate and positioning plate according to predetermined order stage by stage applies torque, and after fastening, the vertical gap between the bottom surface of lower flange plate and the upper surface of positioning plate is measured at multiple positions and adjusted according to bolt fastening state, form "torque control+gap measurement+bolt adjustment" closed-loop control, so that the lift-off gap is accurately controlled within the millimeter level allowable deviation range of design lift-off gap value.

Description

Technical Field

[0001] This invention relates to the field of seismic resistance and construction technology of building structures, and in particular to an installation method for a removable seismic isolation bearing. Background Technology

[0002] In my country's high-intensity earthquake zones, important public buildings widely employ seismic isolation technology to enhance their seismic performance. For structures with a large height-to-width ratio or significant seismic loads, to prevent supports from being damaged by excessive vertical tensile stress under strong earthquakes, "liftable seismic isolation bearings" with vertical displacement release functions have been introduced in engineering projects. These bearings release tensile forces by allowing limited vertical lift-off displacement and utilize specially designed shear keys to cooperate with grooves in the substructure to transfer horizontal shear forces.

[0003] However, the unique structure of the liftable seismic isolation bearing places extremely high precision requirements on its installation, which existing conventional seismic isolation bearing installation methods cannot meet. On the one hand, aligning the shear key is difficult; if the shear key and the groove of the lower positioning plate are not precisely aligned, it will directly affect the transmission path of horizontal shear force and may even cause shear failure of the connecting components (connecting bolts). On the other hand, controlling the lift-off gap is extremely difficult. The bearing installation must ensure that there is a precisely designed gap between the lower flange plate and the positioning plate. If this gap is too small, it cannot effectively release tensile force; if it is too large, it will affect the vertical stiffness of the structure during normal use.

[0004] In practical engineering, the installation process of liftable supports is complex, involves many embedded components, and has a long construction period. Traditional installation techniques often fail to guarantee that the support will maintain the millimeter-level gap and alignment accuracy required by the design upon final delivery. This can lead to quality problems such as excessive gap deviation or jamming of shear keys, posing significant construction risks. Therefore, there is an urgent need for an installation method that can achieve high-precision alignment and effectively ensure that the final lift-off gap meets design requirements. Summary of the Invention

[0005] The main objective of this invention is to provide an installation method for a removable seismic isolation bearing to solve the above-mentioned technical problems.

[0006] The objective of this invention can be achieved by adopting the following technical solution: A method for installing a liftable seismic isolation bearing, the liftable seismic isolation bearing comprising a bearing body and a positioning plate disposed on a substructure member, the bearing body comprising a lower flange plate with a shear key, the upper surface of the positioning plate having a placement groove that mates with the shear key; the method comprising: The positioning plate is pre-embedded and fixed on the lower structural member so that the center position of the placement groove and the groove plane meet the predetermined coordinate and level requirements; The support body is hoisted above the positioning plate, and the shear key is inserted into the placement groove under guidance to complete the alignment of the shear key with the placement groove; The connecting bolts arranged between the lower flange plate and the positioning plate, which are used to anchor the lower flange plate to the lower structural member, are subjected to torque in stages according to a predetermined tightening sequence to the target torque value. After tightening, the vertical gap between the bottom surface of the lower flange plate and the upper surface of the positioning plate is measured at multiple measurement positions. The tightening state of the connecting bolts is adjusted according to the measurement results so that the vertical gap is within the allowable deviation range of the designed lift-off gap value. A connection is established between the support body and the superstructure components to be constructed subsequently. During the construction of the superstructure, the change data of the vertical gap is obtained using a gap monitoring device installed on the support body, and the vertical gap is confirmed to deviate from the allowable deviation range based on the change data.

[0007] The beneficial technical effects of this invention are as follows: By precisely pre-embedding and fixing a positioning plate with a placement groove during the substructure construction stage, the center coordinates and groove plane of the placement groove meet the predetermined accuracy requirements in the early stages of construction. Based on this, a guiding method is used during the support hoisting process to reliably insert the shear key on the lower flange plate into the placement groove. This fundamentally solves the problem of the difficulty in accurately aligning the shear key and groove in existing liftable seismic isolation supports, ensuring reliable transmission of horizontal shear force along the design path and preventing shear failure of the connecting bolts. Simultaneously, by applying torque in stages to the connecting bolts arranged between the lower flange plate and the positioning plate in a predetermined sequence, and by measuring the bottom surface of the lower flange plate and the top surface of the positioning plate at multiple locations after tightening, this invention ensures reliable transmission of horizontal shear force along the design path and prevents shear failure of the connecting bolts. The vertical gap between the surfaces is adjusted accordingly to control the bolt tightening, forming a closed-loop control system of "torque control + gap measurement + bolt adjustment." This ensures that the lift-off gap is precisely controlled within the millimeter-level allowable deviation range of the designed lift-off gap value. Furthermore, during the construction of the superstructure, a gap monitoring device installed on the support body continuously acquires data on vertical gap changes and determines whether the gap deviates from the allowable deviation range. This enables dynamic monitoring and necessary correction of the lift-off gap throughout the entire process, effectively overcoming the shortcomings of long construction periods, changes in construction loads, and concrete shrinkage and creep, which make it difficult to maintain the final lift-off gap and alignment accuracy. This improves the reliability of the liftable seismic isolation bearing installation and the safety of the project upon completion. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the installation method provided in an embodiment of the present invention; Figure 2 A schematic diagram of the arrangement of removable seismic isolation bearings applicable to the installation method provided in the embodiments of the present invention; Figure 3 A schematic diagram of the positioning plate of the removable seismic isolation bearing provided in an embodiment of the present invention; Figure 4 A cross-sectional schematic diagram of a removable seismic isolation bearing provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the fit between the shear key and the placement groove in the removable seismic isolation bearing provided in an embodiment of the present invention; Figure 6 This is an internal schematic diagram of the removable seismic isolation bearing provided in an embodiment of the present invention.

[0010] Explanation of reference numerals in the attached figures: In the figure: 10-support body, 20-lower structural component, 23-embedded sleeve, 30-positioning plate, 31-placement groove, 41-upper flange plate, 42-isolation core, 43-lower flange plate, 44-shear key, 50-connecting bolt, 60-upper structural component. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0013] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0014] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0015] Please also refer to Figures 1-6 This invention provides an installation method for a removable seismic isolation bearing, the method comprising the following steps S100~S400.

[0016] This embodiment uses a single removable lead-core rubber seismic isolation bearing in a library project located in a high-intensity seismic fortification zone as an example to illustrate the entire process of the bearing from pre-embedding the lower positioning plate 30 to gap monitoring during the construction of the upper structure. The removable seismic isolation bearing includes a bearing body 10 and a positioning plate 30 connected to the lower structural member 20.

[0017] The support body 10 includes: an upper flange plate 41 for connection with the upper structural member 60 (such as a frame beam); a seismic isolation core 42 formed by multiple layers of rubber and steel plates; a lower flange plate 43 fixed to the lower end of the seismic isolation core 42, wherein the lower flange plate 43 is an integral steel plate structure with a flat lower surface; and a shear key 44 fixed at the center of the lower flange plate 43, wherein the outer dimensions of the shear key 44 match the inner dimensions of the placement groove 31 to form a certain fitting clearance around the perimeter. Preferably, the shear key 44 has a cross-section of 200x200mm and a height of 50mm; the placement groove 31 of the positioning plate 30 has a cross-section of 210x210mm and a depth of 10mm. The positioning plate 30 is set on the lower structural member 20 (such as the lower reinforced concrete pier) and can be prefabricated as a whole steel plate.

[0018] A placement groove 31 is formed on the upper surface of the positioning plate 30. The placement groove 31 is located in the central area of ​​the positioning plate 30, and its planar shape is similar to that of the shear key 44. The opening of the groove faces upward, and the bottom of the groove is a basically horizontal plane. Several holes are also arranged around the perimeter of the positioning plate 30 for anchoring the lower flange plate 43 to the lower structural member 20 with connecting bolts 50. After the support body 10 is installed and the connecting bolts 50 are tightened, a vertical gap is formed in the circumferential direction between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30, which is the designed lift-off gap.

[0019] S100. The positioning plate 30 is pre-embedded and fixed on the lower structural member 20, so that the center position of the placement groove 31 and the groove plane meet the predetermined coordinate and level requirements.

[0020] First, the positioning plate 30 is installed. The positioning plate 30 is pre-embedded and fixed to the top of the lower structural member 20. During this process, the key control indicator is the positional accuracy of the placement groove 31. Construction personnel must use measurement and positioning methods to ensure that the center position (i.e., plane coordinates) and the groove opening plane (i.e., levelness) of the placement groove 31 strictly meet the predetermined coordinate and levelness requirements of the design.

[0021] After confirming that the center position coordinates of the placement groove 31 and the horizontality of the groove plane meet the predetermined requirements, the positioning plate 30 is fixed to the main reinforcement of the lower structural member 20 by anchoring steel bars. Then, concrete is poured and cured to complete the pre-embedding work. In this way, the positioning plate 30 is embedded in the top of the lower structural member 20, the opening of the placement groove 31 is exposed to the outside with its opening facing upwards, and the inside of the placement groove 31 and the surface of the positioning plate 30 are cleaned in preparation for the installation of the support body 10.

[0022] S200. The support body 10 is hoisted above the positioning plate 30, and the anti-shear key 44 is inserted into the placement groove 31 under guidance to complete the alignment of the anti-shear key 44 with the placement groove 31.

[0023] After the positioning plate 30 is fixed and inspected, the support body 10 is hoisted. The support body 10 is hoisted above the positioning plate 30. During the hoisting and descent, the posture of the support body 10 is controlled by guiding measures (such as manual straightening, auxiliary guiding tools, etc.) to ensure that the shear key 44 at the bottom of the lower flange plate 43 is accurately aligned and inserted into the placement groove 31 of the positioning plate 30. When the shear key 44 is completely lowered into the placement groove 31, the alignment of the shear key 44 with the placement groove 31 is completed.

[0024] S300, apply torque to the target torque value in stages according to a predetermined tightening sequence to the connecting bolts 50 arranged between the lower flange plate 43 and the positioning plate 30 for anchoring the lower flange plate 43 to the lower structural member 20, and measure the vertical gap between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30 at multiple measuring positions after tightening. Adjust the tightening state of the connecting bolts 50 according to the measurement results so that the vertical gap is within the allowable deviation range of the designed lift-off gap value.

[0025] A number of bolt holes are arranged circumferentially between the lower flange plate 43 and the positioning plate 30. Each connecting bolt 50 passes through the lower flange plate 43 from top to bottom and connects to the anchoring member embedded in the lower structural member 20. The length of the connecting bolt 50 is determined by design so that when the connecting bolt 50 is tightened to the design target torque value, a predetermined vertical gap, i.e., the design lift-off gap, can be formed between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30.

[0026] After the support body 10 is in place, all connecting bolts 50 are sequentially inserted into the bolt holes on the lower flange plate 43 and connected to the anchors in the substructure. Then, using a torque-controlled tightening tool, each connecting bolt 50 is tightened in stages according to a predetermined tightening sequence. Staged tightening means first pre-tightening all connecting bolts 50 with a smaller torque value, and then gradually increasing the torque applied to the connecting bolts 50 until the target torque value specified in the design is reached, in order to reduce the impact of localized overtightness or looseness on the attitude of the lower flange plate 43.

[0027] After the tightening operation is completed, a gap measuring tool is used to measure the vertical gap between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30 at multiple measuring positions (e.g., different orientations of the edge of the lower flange plate 43).

[0028] The measured vertical gap values ​​are compared with the designed lift-off gap values ​​to determine whether the gaps at each measuring point are within the allowable deviation range of the designed lift-off gap value. If the gaps at individual measuring points are found to be too large or too small, the local posture of the lower flange plate 43 is fine-tuned by appropriately reducing or increasing the tightening degree of the corresponding connecting bolts 50, and the vertical gaps at the relevant positions are remeasured after adjustment. Through multiple iterative measurements and adjustments, the vertical gaps at all selected measurement positions are ultimately within the pre-set designed lift-off gap value or its allowable deviation range, thereby achieving precise setting and uniform control of the lift-off gap. This process ensures that there is a preset physical gap between the lower flange plate 43 and the positioning plate 30 in the initial installation state of the support, thereby allowing the support to undergo limited vertical lift-off displacement when encountering vertical tension caused by a rare earthquake, avoiding tensile damage to the rubber inside the support body 10.

[0029] S400: Establish a connection between the support body 10 and the superstructure component 60 to be constructed subsequently, and during the construction of the superstructure, obtain the change data of the vertical gap using a gap monitoring device installed at the support body 10, and confirm whether the vertical gap deviates from the allowable deviation range based on the change data.

[0030] After the installation and clearance adjustment of the support body 10 are completed, a connection is established between the support body 10 and the superstructure components 60 (e.g., the superstructure frame) to be constructed subsequently. Then, the superstructure construction phase begins, such as pouring superstructure concrete and increasing floor loads. During this period, a clearance monitoring device pre-installed at the support body 10 is used to continuously or periodically obtain data on changes in the vertical clearance.

[0031] Based on the acquired change data, it is confirmed in real time whether the vertical clearance has changed abnormally and deviated from the allowable deviation range. When the change data indicates that the vertical clearance remains within the allowable range, it can be considered that the liftable seismic isolation bearing is still in normal working condition under the action of construction disturbance and structural deformation. If the change data indicates that the vertical clearance exceeds the allowable deviation range, a prompt is issued to the construction management personnel, who will further analyze the cause and adjust the connection status or construction conditions of the bearing body 10 as needed to ensure that the liftable clearance meets the design requirements when it is finally put into use. This step aims to eliminate the impact of factors such as increased construction load and concrete shrinkage and creep on the adjusted liftable clearance, ensuring that the bearing is still in the optimal working condition required by the design when the project is completed.

[0032] As can be seen from the above implementation method, this method first embeds and precisely positions a positioning plate 30 with a groove 31 on the lower structural member 20, so that the center position of the groove 31 and the groove plane meet the predetermined coordinate and level requirements at the initial stage of construction, providing a reliable benchmark for the accurate insertion and alignment of the shear key 44. Subsequently, during the hoisting of the support body 10, the shear key 44 on the lower flange plate 43 is accurately inserted into the groove 31 of the positioning plate 30 under guidance, completing the alignment of the two. This solves the problem of the shear key 44 and the groove being difficult to align accurately in the traditional method from the source, thereby ensuring the reliable transmission of horizontal shear force and avoiding the potential for shear failure of the connecting bolt 50 due to alignment deviation.

[0033] Based on this, this method applies torque in stages to the connecting bolts 50 arranged between the lower flange plate 43 and the positioning plate 30 according to a predetermined tightening sequence. After tightening, the vertical gap between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30 is measured at multiple locations. The tightening state of each connecting bolt 50 is then repeatedly adjusted based on the measurement results to ensure that the vertical gap at each measuring point is within the allowable deviation range of the designed lift-off gap value. This achieves closed-loop control of the lift-off gap through "torque control + gap measurement + bolt adjustment." This method avoids both the problem of insufficient vertical tension due to excessively small gaps and the problem of insufficient vertical stiffness during normal use due to excessively large gaps, significantly improving the accuracy of lift-off gap control.

[0034] Furthermore, this method also establishes a connection between the support body 10 and the subsequent superstructure components 60, while simultaneously installing a gap monitoring device at the support body 10. During the superstructure construction, it continuously acquires data on vertical gap changes and determines whether the vertical gap deviates from the allowable deviation range. This allows the condition of the liftable seismic isolation bearing to be continuously tracked and verified over a longer construction period. If abnormal changes in the gap occur due to construction loads, concrete shrinkage, or other factors, timely detection and adjustments can be made to ensure that the bearing maintains the designed lift-off gap and good alignment upon final project delivery. This effectively overcomes construction quality risks such as excessive gap deviation and shear key jamming in existing technologies.

[0035] In one embodiment, before pouring concrete for the lower structural member 20, the anchoring steel bar – embedded sleeve 23 assembly welded to the positioning plate 30 is fixed together with the steel bar skeleton, so that the embedded sleeve 23 is located below the positioning plate 30 and coaxial with the bolt holes on the positioning plate 30; when the support body 10 is installed, the connecting bolts 50 pass through the lower flange plate 43 and the positioning plate 30 from top to bottom and are screwed into the embedded sleeve 23, thereby anchoring the lower flange plate 43 to the lower structural member 20.

[0036] In one embodiment, the method further includes stress monitoring of the shear key 44. Strain gauges are attached to the side of the shear key 44 on the support body 10 to monitor the stress state of the shear key 44 in real time during construction, assess whether it is within the normal working range, and prevent excessive local pressure on the shear key 44 due to installation deviations.

[0037] In one embodiment, the step of pre-embedding and fixing the positioning plate 30 onto the lower structural member 20, so that the center position of the placement groove 31 and the groove plane meet predetermined coordinate and levelness requirements, includes: A measurement control network is established to control the axis and elevation of the lower structural member 20, and an auxiliary control line is set on the measurement control network to control the center position of the placement groove 31.

[0038] Specifically, at the construction site, in addition to establishing a conventional main control network for controlling the axis and elevation of the substructure component 20, an auxiliary control line needs to be specifically established for the placement groove 31 of the positioning plate 30. This auxiliary control line is arranged with the theoretical center of the placement groove 31 as the reference, forming a "dual reference" control system to eliminate the cumulative error caused by long-distance measurement.

[0039] Using a total station, the center position of the placement groove 31 is laid out to the predetermined coordinate position according to the measurement control network and the auxiliary control line, and the positioning plate 30 is leveled using a level measuring instrument.

[0040] Specifically, after the positioning plate 30 arrives on site, it is first placed on the temporary support adjustment system on top of the steel reinforcement frame of the lower structural member 20. Surveyors use a high-precision total station, combined with the main control network and auxiliary control lines, to precisely lay out the center point of the placement groove 31 to the design coordinate position. While adjusting the planar position, a leveling instrument (such as a high-precision electronic level or laser level) is used to level the surface of the positioning plate 30. By adjusting the temporary support below, the elevation and inclination of the positioning plate 30 are finely adjusted to ensure that the groove opening plane of the placement groove 31 meets extremely high levelness requirements (e.g., levelness deviation controlled within 1‰), thereby ensuring that the bottom surface of the placement groove 31 is parallel to the horizontal plane.

[0041] After confirming that the center position coordinates of the placement groove 31 and the horizontality of the groove opening of the placement groove 31 meet the predetermined requirements, the positioning plate 30 is welded and fixed to the main reinforcement of the lower structural member 20.

[0042] Specifically, after fine-tuning and verification confirming that the coordinate deviation and levelness are within the allowable range, the positioning plate 30 is finally fixed. At this time, the positioning plate 30 or its lower anchoring sleeve assembly is fixed to the vertical main reinforcement of the lower structural member 20 at multiple points and in multiple directions to ensure that the positioning plate 30 does not shift or deflect before the concrete solidifies, thereby permanently locking the center position and levelness of the placement groove 31 in the predetermined state.

[0043] In one embodiment, the step of guiding the insertion of the anti-shear key 44 into the placement groove 31 to complete the alignment of the anti-shear key 44 with the placement groove 31 includes: During the hoisting process of the support body 10, video monitoring equipment or laser guidance tools are used to assist in observing the relative positions of the shear key 44 and the placement groove 31; When the shear key 44 approaches the placement groove 31, the hoisting is paused, and the position of the lower flange plate 43 is finely adjusted using a manual fine-tuning tool; Continue lowering the support body 10 until the anti-shear key 44 falls into the placement groove 31; After the support body 10 is in place, use an endoscope or feeler gauge to check whether the gap between the shear key 44 and the inner wall of the placement groove 31 is uniform.

[0044] In one embodiment, the step of guiding the insertion of the anti-shear key 44 into the placement groove 31 to complete the alignment of the anti-shear key 44 with the placement groove 31 specifically includes the following steps: First, during the hoisting of the support body 10, video monitoring equipment or laser guidance tools are used to assist in observing the relative position of the shear key 44 and the placement groove 31. Specifically, due to the large size of the support body 10, the operator's line of sight is easily obstructed during hoisting. Therefore, a video display terminal can be installed in the tower crane cab to monitor the relative position of the bottom of the lower flange plate 43 and the positioning plate 30 in real time through a camera installed on the hook or above the support; alternatively, ground personnel can use laser pointers, laser line projectors, or other guidance tools to project the center projection or edge position of the shear key 44 onto the positioning plate 30 to assist the hoisting operator in judging the horizontal position deviation.

[0045] Secondly, when the shear key 44 approaches the placement groove 31, the hoisting is paused, and the position of the lower flange plate 43 is adjusted using manual fine-tuning tools. Specifically, when the support body 10 descends to a certain height from the upper surface of the positioning plate 30, such as 1 meter, the tower crane is instructed to pause its descent. At this time, the construction personnel use manual fine-tuning tools (such as steel crowbars or guide bars) to make slight horizontal pushing, pulling, or rotation adjustments to the suspended support body 10, so that the contour of the shear key 44 is aligned with the opening of the placement groove 31.

[0046] Next, continue lowering the support body 10 until the shear key 44 falls into the placement groove 31. Specifically, after confirming that the alignment is correct, instruct the hoisting equipment to slowly lower the support, so that the shear key 44 slides smoothly and vertically into the placement groove 31, until the support body 10 is seated above the positioning plate 30 by the connecting bolts 50 or temporary supports.

[0047] Finally, after the support body 10 is in place, use an endoscope or feeler gauge to check whether the gap between the shear key 44 and the inner wall of the placement groove 31 is uniform. Specifically, after the support is in place, the shear key 44 is located inside the groove, and its alignment is difficult to observe directly from the outside. At this time, use the probe of an industrial endoscope to penetrate into the gap between the shear key 44 and the groove to take pictures or videos for observation, or use a special feeler gauge to measure the physical gap between the side of the shear key 44 and the inner wall of the groove around the support body 10. If the gap values ​​are basically consistent (e.g., meeting the alignment deviation required by the design, such as ±1mm), the alignment is considered qualified; if the gap is extremely uneven (e.g., one side is stuck, and the gap on one side is too large), it is necessary to re-lift or adjust until the alignment meets the requirements. This step ensures that the horizontal shear force can be transmitted evenly and avoids eccentric force.

[0048] This embodiment introduces visual aids such as video monitoring or laser guidance during the hoisting process of the support body 10, and combines them with manual fine-tuning tools to make fine adjustments to the lower flange plate 43. This allows the shear key 44 to be visualized and controlled for alignment before it is fully in place, significantly reducing the positional deviation and the probability of repeated hoisting caused by "blind hoisting" based on the experience of hoisting workers. This improves the success rate of the first alignment of the shear key 44 into the placement groove 31 and the installation efficiency.

[0049] Furthermore, by pausing the hoisting when the shear key 44 approaches the groove and making local fine adjustments by using small horizontal push-pull or rotation, fine alignment can be completed while the overall weight of the support body 10 is still borne by the hoisting equipment. This avoids jamming, collision, or even component damage caused by forcibly pressing down on the shear key 44 when it is not aligned, and ensures that the gap around the shear key 44 is basically uniform, which is conducive to the reliable transmission of subsequent horizontal shear force along the predetermined path and prevents bolts, concrete edges, and other non-designed components from being sheared.

[0050] Furthermore, after the bearing body 10 is in place, the gap between the shear key 44 and the groove is inspected using an endoscope or feeler gauge. This allows for intuitive and quantitative verification of the alignment quality, avoiding reliance on appearance or experience alone to judge the alignment. This inspection step ensures that the fit between the shear key 44 and the groove can be confirmed and recorded before concealment, improving the traceability of construction quality and reducing the risk of shear concentration or "jamming" due to poor alignment in later use. Overall, this enhances the reliability and safety of the installation of the liftable seismic isolation bearing.

[0051] In this embodiment, the insertion of the anti-shear key 44 into the placement groove 31 under guidance can be achieved not only by using manual fine-tuning tools (such as steel pry bars) but also by using a micro-powered jacking device. When the support body 10 is suspended above the positioning plate 30, the micro-powered jacking device is used to adjust the horizontal displacement of the support body 10 at the millimeter level, with visual assistance, to ensure that the gap around the anti-shear key 44 is uniform.

[0052] In one embodiment, S300, the connecting bolts 50 arranged between the lower flange plate 43 and the positioning plate 30 for anchoring the lower flange plate 43 to the lower structural member 20 are subjected to torque in stages according to a predetermined tightening sequence to a target torque value. After tightening, the vertical gap between the bottom surface of the lower flange plate 43 and the upper surface of the positioning plate 30 is measured at multiple measuring positions. Based on the measurement results, the tightening state of the connecting bolts 50 is adjusted so that the vertical gap is within the allowable deviation range of the designed lift-off gap value. Specifically, this includes the following steps: S310. Using a torque wrench, gradually increase the torque in at least two stages in a diagonal sequence until the target torque value is reached to tighten the connecting bolt 50.

[0053] Specifically, a calibrated torque wrench or an electric wrench with torque-angle dual control function should be selected as the tightening tool. To prevent the lower flange plate 43 from warping or tilting due to uneven force, the tightening sequence must strictly follow the "diagonal symmetry" principle (for example, tighten bolt #1 first, then tighten the bolts on its diagonal, and so on). The tightening process should be carried out in stages. For example, first tighten all bolts to a certain percentage (e.g., 50%) of the target torque value (given by the design unit based on bolt specifications and preload requirements), and after the overall stability is achieved, proceed to the next stage of tightening until the final target torque value is reached.

[0054] S320. After the connecting bolts 50 are tightened, the vertical clearance is measured at the midpoint of at least four edges of the bottom surface of the lower flange plate 43 using a clearance gauge.

[0055] Specifically, once all connecting bolts 50 have reached the target torque, a clearance check is immediately performed. Using a high-precision clearance gauge, representative locations around the bottom surface of the lower flange plate 43 are selected as measurement points. Preferably, measurements are taken at the midpoints of the four edges of the rectangular bottom surface of the lower flange plate 43, and the measured vertical clearance values ​​at each point are recorded. This measurement value directly reflects the actual lift-off clearance size formed by the support body 10 under the current bolt pre-tightening state.

[0056] S330. If the vertical gap at any of the midpoints of the edges exceeds the allowable deviation range, the connection bolts 50 are loosened or tightened again to adjust until the vertical gaps at all the midpoints of the edges are within the allowable deviation range.

[0057] Specifically, the measured gap values ​​are compared with the designed lift-off gap value (e.g., 5mm) and its allowable deviation range (e.g., ±0.5mm). If a gap is found to be too large (e.g., greater than 5.5mm), it indicates that the bolt preload in that area may be insufficient, and the bolt torque in that area needs to be appropriately increased for re-tightening. If a gap is found to be too small (e.g., less than 4.5mm), it indicates that the bolts in that area are too tight, and the bolts in that area need to be appropriately loosened. After adjustment, the gap at that point and adjacent points must be remeasured. After multiple fine-tuning iterations, the vertical gaps at all measuring points around the lower flange plate 43 are stabilized within the allowable deviation range, thereby ensuring that the support has a uniform and design-compliant lift-off capability in a horizontal state.

[0058] In this embodiment, a torque wrench is used to tighten the connecting bolts 50 in stages according to the diagonal sequence. This effectively avoids problems such as uneven force on the lower flange plate 43 caused by excessive torque in a single tightening or improper sequence, and ensures the uniform application of pre-tightening force on the connecting bolts 50, laying the foundation for forming a stable lifting gap.

[0059] Furthermore, by measuring the vertical clearance at key locations such as the midpoints of the four edges of the bottom surface of the lower flange plate 43 after the connecting bolts 50 are tightened, the actual clearance distribution after the support is installed can be fully and accurately reflected, and abnormal clearance caused by factors such as bolt preload deviation can be detected in a timely manner.

[0060] This embodiment establishes a closed-loop control mechanism of "measurement-adjustment-remeasurement". Once the vertical gap at any measurement point is found to exceed the allowable deviation range, targeted fine-tuning is immediately performed by loosening or retightening the corresponding connecting bolts 50 until the gaps at all points meet the requirements. This dynamic adjustment method based on actual measurement feedback overcomes the shortcomings of traditional installations that rely solely on torque values ​​for control while ignoring actual gap deviations. It ensures that the final lift-off gap height is accurate and uniform, thereby guaranteeing that the liftable seismic isolation bearing can release vertical tension through this gap under seismic action.

[0061] In a preferred embodiment, the torque is gradually increased in at least two stages, including: a first stage applying a first torque value, which is 25% of the target torque value; a second stage applying a second torque value, which is 50% of the target torque value; and a third stage applying the target torque value. Taking a target torque value of 600 Nm in a certain project as an example, in the first stage, all connecting bolts 50 are pre-tightened to about 150 Nm in diagonal order to initially position the lower flange plate 43; in the second stage, the torque is increased to about 300 Nm to further bring the lower flange plate 43 closer to the design position; and in the third stage, it is increased to 600 Nm to complete the final tightening. After each stage, a quick re-inspection can be performed if necessary to ensure that the torque distribution of each connecting bolt 50 is uniform. This three-stage gradual torque increase method has a small single torque increment, which is more conducive to controlling the slight warping of large-specification supports during the tightening process. It is particularly suitable for seismic isolation supports with a large number of bolts and a large area of ​​the lower flange plate 43.

[0062] In another embodiment, the torque is gradually increased in at least two stages, including: applying a first torque value in the first stage, where the first torque value is 40% to 60% of the target torque value; and applying the target torque value in the second stage. Specifically, all connecting bolts 50 can be tightened sequentially diagonally to approximately half of the target torque value. For example, if the target torque value is 600 Nm, the first stage tightens each bolt to approximately 300 Nm, ensuring that the lower flange plate 43 is basically in contact with the design position under relatively low overall stress. After confirming that all bolts have uniformly reached the first torque value, the torque is then increased to 600 Nm in the same diagonal sequence, achieving a one-time final locking of all bolts. This two-stage "pre-tightening + final tightening" method effectively reduces local unevenness caused by a single large torque application.

[0063] By using the two phased torque control methods described above, the construction unit can choose one to adopt based on the on-site equipment capacity, support specifications, and construction habits. Both methods gradually approach the target torque value in multiple stages, and with the diagonal tightening sequence, they effectively improve the uniformity and controllability of the 50mm preload of the connecting bolts. This provides a stable premise for subsequent vertical clearance measurement and bolt fine-tuning, thus helping to ultimately form a lift-off clearance that meets the design requirements.

[0064] In one embodiment, the gap monitoring device includes a displacement sensor disposed between the lower flange plate 43 and the positioning plate 30. The step of obtaining change data of the vertical gap using the gap monitoring device disposed at the support body 10, and confirming whether the vertical gap deviates from the allowable deviation range based on the change data, specifically includes the following steps: S410. After the support body 10 is installed and before the construction of the superstructure begins, set the initial reading of the displacement sensor.

[0065] Specifically, after the support body 10 has been finally tightened and the gap has been fine-tuned, and has been accepted by the supervising engineer, the monitoring preparation stage begins. At this time, a displacement sensor (not shown separately in the attached figure) is installed in the gap between the lower flange plate 43 and the positioning plate 30. Preferably, the displacement sensor can be a high-precision eddy current sensor, connected to the data acquisition terminal wirelessly or via a wired connection. After the sensor is securely installed, before large-scale construction of the superstructure begins, all displacement sensors are zeroed or their current readings are recorded as a reference value, i.e., the initial reading is set. This initial reading represents the vertical gap state of the support body 10 under the "zero condition" or "initial condition," for example, corresponding to a design lift-off gap value of 5 mm.

[0066] S420. During the construction of the superstructure, the real-time value of the vertical gap is automatically collected at a preset frequency, and the change of the real-time value relative to the initial reading is calculated.

[0067] Specifically, as the construction of the superstructure progresses, such as pouring concrete layer by layer and building walls, the load on the superstructure gradually increases, and concrete shrinkage and creep also begin to occur. During this period, real-time values ​​from displacement sensors at each measuring point are automatically collected at a pre-set frequency, such as once per hour or once per day. Then, the difference between each collected real-time value and the initial reading recorded in step S410 is calculated to obtain the change in vertical clearance (ΔH). If the change ΔH is positive, it indicates that the clearance has increased; if it is negative, it indicates that the clearance has decreased (i.e., the support body 10 has settled under pressure). The calculated change is compared in real time with the allowable deviation range (e.g., ±0.5mm). If the change is always within the allowable range, it indicates that the clearance is stable; if the change exceeds the allowable range at a certain moment, an automatic warning is triggered, indicating to the construction personnel that the clearance has changed significantly and may be affected by uneven settlement, construction overload, or unexpected disturbance.

[0068] This embodiment constructs a "close-fitting" monitoring system for the lifting gap by directly installing a displacement sensor between the lower flange plate 43 and the positioning plate 30. Compared with traditional manual periodic inspections, this device can achieve non-contact, all-weather automated data acquisition, improving monitoring efficiency and data continuity.

[0069] Specifically, this embodiment emphasizes setting the initial reading at the point when "the support installation is completed and the superstructure construction begins." This establishes an accurate "zero point," eliminating the influence of sensor installation errors and ensuring that the data subsequently monitored accurately reflects the "net change" in clearance caused solely by superstructure construction and environmental factors.

[0070] Furthermore, by automatically collecting real-time values ​​at a preset frequency and calculating the changes relative to the initial readings, the system can keenly detect minute fluctuations in the gap. This dynamic monitoring mode based on relative changes not only allows for a direct assessment of whether the current gap deviates from the allowable deviation range required by the design (e.g., ±0.5mm), but also provides timely and quantitative data for subsequent construction adjustments. This ensures that the removable seismic isolation bearing remains under control throughout the long construction period, preventing the accumulation of potential quality hazards due to a lack of awareness.

[0071] In one embodiment, the process of confirming whether the vertical gap deviates from the allowable deviation range based on the change data, and when confirming that the vertical gap deviates from the allowable deviation range based on the change data, further includes: selectively removing temporary construction loads near the support body 10 and / or readjusting the tightness of the connecting bolts 50 to restore the vertical gap to the allowable deviation range.

[0072] In one embodiment, the process of confirming whether the vertical gap deviates from the allowable deviation range based on the change data, and when confirming that the vertical gap deviates from the allowable deviation range based on the change data, further includes the following steps: First, investigate the cause of the gap deviation. When the real-time value fed back by the gap monitoring device shows that the vertical gap exceeds the allowable deviation range (for example, the monitored value is less than 4.5mm or greater than 5.5mm, that is, the deviation from the design value is more than ±0.5mm), the on-site technicians should immediately inspect the construction environment around the support body 10.

[0073] Secondly, based on the investigation results, one or two of the following measures may be selectively adopted: Measure 1: Remove temporary construction loads near the support body 10. Specifically, if an investigation reveals a large amount of undesigned temporary loads (such as excessive steel bars, formwork, scaffolding, or large construction machinery) on the floor slab or beam near the support, these temporary loads may cause local structural deformation, thereby compressing or stretching the vertical clearance at the support. In this case, personnel or machinery should be immediately organized to remove or disperse these temporary loads to a safe area. For example, when the main structure of a project reached the 5th floor, monitoring data showed that the average clearance at a certain support suddenly dropped from 5.0 mm to 4.7 mm. An investigation revealed that this was caused by a large amount of steel bars temporarily piled up in an adjacent area. After removing this load, the displacement sensor reading gradually recovered and stabilized at 4.9 mm, returning to the allowable deviation range, thus eliminating the alarm.

[0074] Measure 2: Readjust the tightness of the connecting bolts 50. Specifically, if there is no obvious temporary load near the support, or if the vertical clearance has not returned to the allowable deviation range after the load is removed (this may be due to permanent deformation caused by concrete shrinkage and creep, uneven foundation settlement, or bolt stress relaxation), then the connecting bolts 50 need to be adjusted a second time. Construction personnel need to bring a torque wrench and clearance measuring tools to re-enter the support joint area. Depending on whether the clearance is too large or too small, they should tighten or loosen the connecting bolts 50 appropriately, and measure the clearance until the vertical clearance value returns to the allowable deviation range.

[0075] Finally, after taking the above measures to restore the vertical gap to the allowable deviation range, record the adjustment process and the adjusted gap value, and continue subsequent automated monitoring.

[0076] This embodiment distinguishes between two situations: "temporary load disturbance" and "change in structure / bolt status." It employs two targeted strategies, "unloading" and "re-adjusting bolts," respectively, to effectively address the disturbances to the precision lift-off gap caused by various complex working conditions during the long construction period. This ensures that the core functional parameters (lift-off gap) of the liftable seismic isolation bearing still accurately meet the design requirements when it is finally completed and delivered, thus preventing the bearing from losing its tensile or shear resistance due to gap failure.

[0077] In one embodiment, before establishing a connection between the support body 10 and the superstructure member 60 to be constructed subsequently, the method further includes: providing a rigid protective cover in the exposed areas of the shear key 44 and the placement groove 31.

[0078] Specifically, after the support body 10 is hoisted into place and the gap adjustment is completed, the superstructure has not yet been constructed, and the gap between the shear key 44 around the lower flange plate 43 and the groove of the positioning plate 30 is open. To prevent grout from splashing in during subsequent concrete pouring, or welding slag and debris from the construction site from falling and jamming the gap, a rigid protective cover is required. This protective cover can be made of thin steel plate or rigid plastic, and its shape matches the lower contour of the support, completely covering the mating area of ​​the shear key 44 and the groove. The rigid protective cover is fixed to the outside of the lower flange plate 43 by magnetic attraction, snaps, or other detachable means, forming a protective space, thereby effectively preventing foreign objects from intruding and damaging the lifting gap and the alignment of the shear key 44.

[0079] In one embodiment, the design lift-off gap value is 5mm to 20mm, and the allowable deviation range is ±0.5mm.

[0080] Specifically, based on the design requirements of the seismic isolation structure, the design unit will calculate the required vertical lift-off displacement. This embodiment of the method is applicable to the installation of various liftable bearings with design lift-off gap values ​​ranging from 5mm to 20mm. For example, in a library project in a high-intensity seismic zone, the design calculation determines a lift-off gap value of 5mm; in another high-rise building project, the design gap might be 15mm. Regardless of the specific design value, this method requires that during static acceptance after installation, the deviation between the measured gap value and the design value must be strictly controlled within ±0.5mm. For example, if the design gap is 5mm, the measured value must be between 4.5mm and 5.5mm to ensure proper release of vertical tension in the bearing during an earthquake.

[0081] In one embodiment, before pre-embedding and fixing the positioning plate 30 onto the lower structural member 20, the method further includes: establishing a three-dimensional model based on the design drawings of the liftable seismic isolation bearing, and performing a collision check to verify the feasibility of the shear key 44 falling into the placement groove 31.

[0082] Specifically, during the construction preparation phase, technicians, based on the detailed drawings provided by the bearing manufacturer, used BIM (Building Information Modeling) to create a 3D model including the bearing body 10, positioning plate 30, and lower support reinforcement. Simulated assembly and collision checks were performed using software, with a focus on verifying whether the shear key 44 would be interfered with by other components along the descent path of the bearing body 10. If the shear key 44 was found to overlap with a certain reinforcement bar, the arrangement of that reinforcement bar was adjusted in advance to avoid problems with its descent during on-site hoisting.

[0083] The deformation of the positioning plate 30 under construction loads and concrete shrinkage was analyzed, and pre-control measures were formulated accordingly. Specifically, finite element analysis software was used to simulate the shrinkage deformation of the lower support after concrete pouring, as well as the minor deflection or settlement that the positioning plate 30 might experience during the gradual application of construction loads on the upper structure. Based on the analysis results, the potential tilt or unevenness of the surface of the positioning plate 30 was predicted, and reverse deformation (pre-camber) or stiffening of the positioning plate 30 was pre-set during the pre-embedding stage to counteract the effects of subsequent deformation and ensure that the final placement groove 31 meets the high flatness requirements.

[0084] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for installing a liftable seismic isolation bearing, the liftable seismic isolation bearing comprising a bearing body and a positioning plate disposed on a substructure member, the bearing body comprising a lower flange plate with a shear key, the upper surface of the positioning plate having a placement groove that mates with the shear key; characterized in that, The method includes: The positioning plate is pre-embedded and fixed on the lower structural member so that the center position of the placement groove and the groove plane meet the predetermined coordinate and level requirements; The support body is hoisted above the positioning plate, and the shear key is inserted into the placement groove under guidance to complete the alignment of the shear key with the placement groove; The connecting bolts arranged between the lower flange plate and the positioning plate, which are used to anchor the lower flange plate to the lower structural member, are subjected to torque in stages according to a predetermined tightening sequence to the target torque value. After tightening, the vertical gap between the bottom surface of the lower flange plate and the upper surface of the positioning plate is measured at multiple measurement positions. The tightening state of the connecting bolts is adjusted according to the measurement results so that the vertical gap is within the allowable deviation range of the designed lift-off gap value. A connection is established between the support body and the superstructure components to be constructed subsequently. During the construction of the superstructure, the change data of the vertical gap is obtained using a gap monitoring device installed on the support body, and the vertical gap is confirmed to deviate from the allowable deviation range based on the change data.

2. The method according to claim 1, characterized in that, The step of pre-embedding and fixing the positioning plate onto the lower structural member, so that the center position of the placement groove and the groove plane meet the predetermined coordinate and levelness requirements, includes: Establish a measurement control network for controlling the axis and elevation of the lower structural components, and set an auxiliary control line on the measurement control network for controlling the center position of the placement groove; Using a total station, the center position of the placement groove is laid out to the predetermined coordinate position according to the measurement control network and the auxiliary control lines, and the positioning plate is leveled using a level measuring instrument; After confirming that the center position coordinates of the placement groove and the horizontality of the groove opening meet the predetermined requirements, the positioning plate is welded and fixed to the main reinforcement of the lower structural member.

3. The method according to claim 1, characterized in that, The step of guiding the insertion of the shear key into the placement groove to complete the alignment of the shear key with the placement groove includes: During the hoisting of the support body, video monitoring equipment or laser guidance tools are used to assist in observing the relative position of the shear key and the placement groove; When the shear key approaches the placement groove, the hoisting is paused, and the position of the lower flange plate is adjusted using a manual fine-tuning tool; Continue lowering the support body until the anti-shear key falls into the placement groove; After the support body is in place, use an endoscope or feeler gauge to check whether the gap between the shear key and the inner wall of the placement groove is uniform.

4. The method according to claim 1, characterized in that, The process involves applying torque to the connecting bolts arranged between the lower flange plate and the positioning plate, used to anchor the lower flange plate to the lower structural member, in stages according to a predetermined tightening sequence until a target torque value is reached. After tightening, the vertical gap between the bottom surface of the lower flange plate and the upper surface of the positioning plate is measured at multiple measurement locations. Based on the measurement results, the tightening state of the connecting bolts is adjusted so that the vertical gap is within the allowable deviation range of the designed lift-off gap value. This includes: Using a torque wrench, gradually increase the torque in at least two stages in a diagonal sequence until the target torque value is reached, and tighten the connecting bolts. After the connecting bolts are tightened, the vertical clearance is measured at the midpoint of at least four edges on the bottom surface of the lower flange plate using a clearance gauge. If the vertical gap at any of the midpoints of the edges exceeds the allowable deviation range, the adjustment is made by loosening or retightening the connecting bolts until the vertical gaps at all the midpoints of the edges are within the allowable deviation range.

5. The method according to claim 4, characterized in that, The method of gradually increasing the torque in at least two stages includes: applying a first torque value in the first stage, the first torque value being 40% to 60% of the target torque value; and applying the target torque value in the second stage; or... The torque is gradually increased in at least two stages, including: applying a first torque value in the first stage, the first torque value being 25% of the target torque value; applying a second torque value in the second stage, the second torque value being 50% of the target torque value; and applying the target torque value in the third stage.

6. The method according to claim 1, characterized in that, The gap monitoring device includes a displacement sensor disposed between the lower flange plate and the positioning plate; it establishes a connection between the support body and the superstructure components to be constructed subsequently, and during the construction of the superstructure, uses the gap monitoring device disposed at the support body to obtain the change data of the vertical gap, and confirms whether the vertical gap deviates from the allowable deviation range based on the change data, including: After the support body is installed and before the construction of the superstructure begins, the initial reading of the displacement sensor is set. During the construction of the superstructure, the real-time value of the vertical gap is automatically collected at a preset frequency, and the change of the real-time value relative to the initial reading is calculated.

7. The method according to claim 1, characterized in that, The process of confirming whether the vertical gap deviates from the allowable deviation range based on the change data, and when confirming that the vertical gap deviates from the allowable deviation range based on the change data, further includes: selectively removing temporary construction loads near the support body and / or readjusting the tightening state of the connecting bolts to restore the vertical gap to the allowable deviation range.

8. The method according to claim 1, characterized in that, Before establishing a connection between the support body and the superstructure components to be constructed subsequently, the method further includes: setting a rigid protective cover on the exposed areas of the shear key and the placement groove.

9. The method according to claim 1, characterized in that, The designed lift-off gap value is 5mm to 20mm, and the allowable deviation range is ±0.5mm.

10. The method according to claim 1, characterized in that, Before pre-embedding and fixing the positioning plate onto the lower structural member, the method further includes: A three-dimensional model was built based on the design drawings of the removable seismic isolation bearing, and a collision check was performed to verify the feasibility of the shear key falling into the placement groove. The deformation of the positioning plate under construction load and concrete shrinkage was analyzed, and pre-control measures were formulated accordingly.

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