Pre-pressing method for suspension structure construction

Abstract

The invention provides a pre-pressing method for construction of a suspension structure, and particularly relates to a method for applying a subsequent total load in advance through a pre-pressing device such as a hydraulic jack, so that a floor structure vertically deforms and is locked in advance, and then pressure is balanced and released step by step along with increase of a construction load. Load application and pressure release balance in the whole process is ensured, and structural deformation is in a stable state. According to the method, a structure pre-arching mode is adopted in the earlier stage, after construction of a steel structure outer frame is completed, the follow-up design load amount is obtained through calculation, suspension structure outer frame pre-pressing is conducted, so that the vertical deformation amount is locked in advance, then pressure is released through step-by-step unloading along with increase of the construction load, and the outer frame structure stress is always in a balanced state; the problem that vertical deformation of a floor structure is continuously increased due to load increase in floor construction of a suspension structure is solved. The risks of structural cracking, roof water leakage, building decoration layer damage and the like possibly caused by development of vertical deformation of the floor are reduced to the maximum extent, and the construction quality of the suspension structure is greatly improved.

Description

Technical Field

[0001] The present invention relates to a preloading method for the construction of a suspension structure. Background Art

[0002] A suspension structure building mainly consists of a shaft, a hanger (truss) or a diagonal tie rod, a suspension rod, and each floor slab. The shaft is often made of reinforced concrete structure or steel structure. The inner ends of each floor slab are supported on the shaft, and the outer ends are suspended by suspension rods to columns. The suspension rods are suspended on the hanger (truss) extending from the shaft, or can also be suspended by diagonal tie rods at the top of the shaft. All loads are transmitted to the shaft at the center or both ends, and then transmitted from the shaft to the foundation.

[0003] Through model benefit analysis, the vertical deformation of the floor slab at the edge of the suspended floor is quite different from that at the core tube, such as exceeding 59.8 mm, and relatively large tensile stress may occur in the floor slab. The vertical deformation of the floor slab at the edge of the suspended floor is quite different from that at the core tube.

[0004] During the construction of a suspended steel structure, pre-arching compensation is usually carried out on the steel structure to offset the vertical deformation after the application of subsequent loads. For example, after the installation of the suspended steel structure is completed, the floor slab concrete is poured according to the steel structure engineering of the conventional structural system, that is, the floor slab concrete pouring process is mainly carried out layer by layer once after the laying of each layer of steel structure truss floor formwork, and subsequent secondary structure, installation of mechanical and electrical pipelines, building decoration, etc. According to the above-mentioned floor slab benefit research and analysis of the suspended structure, the tensile stress is relatively large near the cantilever truss and the core tube, and this tensile stress will be superimposed as the load of the floor slab increases. When the floor slab deformation exceeds the stress limit threshold, cracks or even cracking failures will occur in the floor slab at the core tube end. Similarly, the development of the vertical deformation of the floor may also directly lead to the damage of the building decoration layer, etc. Summary of the Invention

[0005] The purpose of the present invention is to provide a preloading method for the construction of a suspension structure.

[0006] To solve the above problems, the present invention provides a preloading method for the construction of a suspension structure, including:

[0007] Step S1, displacement sensors are arranged at the lower chord of the truss to collect the vertical deformation data of the truss; wherein, the suspended outer frame is suspended to the truss connected to the top of the core tube;

[0008] Step S2, by using the reserved pre-tension connecting ear plates at the bottom beam-column joints of the suspension structure, the ear plates are connected to the upper suspension point steel bracket beam;

[0009] Step S3, according to the design related parameters of the suspended outer frame, calculate the increased design loads at each construction stage of the suspended outer frame of the suspended floor;

[0010] Step S4: Set a preloading device for the foundation structure connecting the continuous wall at the lower part of the hanging point steel corbel beam, and connect the hanging point steel corbel beam and the preloading device with steel strands.

[0011] Step S5: Pour the floor concrete. Among them, set stress post-cast strips around the core tube and at the corners where it radiates to the hanging outer frame.

[0012] Step S6: Based on the calculated design load, deduce the applied pressure value of the preloading device. After the floor concrete reaches the preset strength; perform floor preloading by synchronously jacking up based on the applied pressure value through the preloading device.

[0013] Step S7: Seal the post-cast strips of the concrete on each floor, and pour the roof layer concrete in one go.

[0014] Step S8: Construct the secondary structure, install mechanical and electrical pipelines, and perform building decoration on the hanging outer frame; and according to the applied pressure value that the preloading device has already applied, perform corresponding synchronous step-by-step unloading of the applied pressure value on the preloading device until the construction is completed and the preloading device completes the final full unloading.

[0015] Further, in the above method, Step S1 includes:

[0016] Set the displacement sensors at the four corners of the annular truss and the ends of the cantilever truss.

[0017] Further, in the above method, each construction stage at least includes: the stage of pouring each floor, the secondary structure stage, and the building decoration stage.

[0018] Further, in the above method, Step S4 includes:

[0019] Set preloading devices around the bottom of the hanging structure.

[0020] Further, in the above method, the preloading device includes: a hydraulic jack, a static load meter, a steel reaction beam, and a steel bearing bottom beam, where

[0021] The steel reaction beam is connected to the foundation structure of the continuous wall through force-transferring steel bars;

[0022] One end of the hydraulic jack abuts against the steel reaction beam; the other end of the hydraulic jack is connected to the steel bearing bottom beam, and the steel bearing bottom beam is connected to one end of the steel strand;

[0023] One end of the static load meter is connected to the hydraulic jack, and the other end is connected to the control end to realize the interaction between the hydraulic jack and the control end.

[0024] Further, in the above method, in Step S6, the applied pressure value is 50% of the calculated design load corresponding to the construction stage.

[0025] Further, in the above method, in step S6, in order to reduce the pre-pressure provided by the preloading device, except for the roof layer, the floor concrete is poured layer by layer, and the applied pressure value is 50% of the calculated design load corresponding to the stage of pouring the floor concrete layer by layer.

[0026] Further, in the above method, in step S6, based on the vertical deformation data of the truss collected by the displacement sensor, the reference deformation rate is calculated; based on the reference deformation rate, the pressure value applied by the preloading device is controlled.

[0027] Further, in the above method, after step S8, it further includes:

[0028] Except for the preloading device, building decoration is supplemented at the corresponding positions of the bottom layer of the suspended outer frame.

[0029] Compared with the prior art, the present invention provides a method for preloading a suspended structure outer frame. By using a preloading device such as a hydraulic jack, the subsequent total load is applied in advance, so that the vertical deformation of the floor structure is pre-applied and locked, and then the pressure is gradually balanced and released as the construction load increases. Ensure that the load application and pressure release are balanced throughout the process, and the structural deformation is in a stable state.

[0030] In the early stage of the present invention, the structural pre-arch method is adopted. After the steel structure outer frame is constructed, the subsequent design load is calculated to preload the suspended structure outer frame in order to lock the vertical deformation amount in advance, and then the pressure is gradually unloaded and released as the construction load increases. This method keeps the outer frame structure in a balanced stress state all the time, and solves the problem that the vertical deformation of the floor structure continuously increases due to the increase of the load during the construction of the suspended structure floor. It minimizes the risk of structural cracking, roof water leakage, damage to building decoration layers, etc. caused by the development of vertical deformation of the floor to a large extent, and greatly improves the construction quality of the suspended structure. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the preloading method for suspended structure construction according to an embodiment of the present invention;

[0032] Figure 2 It is a side elevation schematic diagram of the preloading device according to an embodiment of the present invention;

[0033] Figure 3 It is a front elevation schematic diagram of the preloading device according to an embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of the stress post-pouring belt according to an embodiment of the present invention. Detailed Embodiments

[0035] To make the above objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] As Figures 1 to 4 shown, the present invention provides a preloading method for the construction of a suspension structure, including:

[0037] Step S1, a displacement sensor 4 is arranged at the lower chord of the truss 1 to collect the vertical deformation data of the truss; wherein, the suspended outer frame 3 is suspended to the truss 1 connected to the top of the core tube 2;

[0038] Here, this method can be implemented after the suspended steel structure outer frame is suspended to the truss and reaches the designed state, that is, after unloading;

[0039] Preferably, displacement sensors 4 can be arranged at a total of 12 locations, including the four corners of the ring truss and the ends of the cantilever trusses;

[0040] Step S2, by using the pre-tensioned connection ear plates reserved at the bottom beam-column joints of the suspension structure, the ear plates are connected to the upper suspension point steel bracket beam 6;

[0041] Step S3, according to the design-related parameters of the suspended outer frame, calculate the increased design loads at each construction stage of the suspended outer frame on the suspended floors;

[0042] Here, each construction stage at least includes: the stage of pouring each floor, the secondary structure stage, and the building decoration stage; preferably, the increased design loads at each construction stage can be set to increase by a preset weight in one stage, such as 10,000 tons in one stage, 20 tons in one stage; the design loads can include: the load of the concrete thickness, the decoration on it, and the installation pipelines, etc.

[0043] Step S4, a preloading device 5 for connecting the foundation structure of the diaphragm wall is arranged under the upper suspension point steel bracket 6, and the upper suspension point steel bracket beam is connected to the preloading device through a steel strand 7;

[0044] Here, the foundation structure of the diaphragm wall can be used to provide the preloading reaction force of the jack of the preloading system to achieve the purpose of preloading the outer frame structure 2;

[0045] Preferably, as Figure 1 shown, preloading devices can be arranged around the bottom of the suspension structure (suspended outer frame);

[0046] Preferably, as Figure 2 and 3 shown, the preloading device 5 includes: a hydraulic jack 51, a static load meter, a steel reaction beam 52, and a steel bearing bottom beam 53, wherein,

[0047] The steel reaction beam is connected to the foundation structure of the continuous wall through the force transmission steel bar 54;

[0048] One end of the hydraulic jack is against the steel reaction beam 52; the other end of the hydraulic jack 51 is connected to the steel bearing bottom beam 53, and the steel bearing bottom beam is connected to one end of the steel strand;

[0049] One end of the static load instrument is connected to the hydraulic jack 51, and the other end is connected to the control end to achieve interaction between the hydraulic jack and the control end;

[0050] Step S5, pouring floor concrete, wherein Figure 4 As shown, stress post-cast strips 8 are arranged around the core tube 2 and at the corners radiating to the hanging outer frame;

[0051] Step S6, based on the calculated design load, the applied pressure value of the preloading device is calculated, and after the floor concrete reaches the preset strength; based on the applied pressure value, the floor is preloaded by synchronously lifting the preloading device;

[0052] Preferably, the applied pressure value is 50% of the calculated design load for the corresponding construction stage;

[0053] More preferably, in order to reduce the preload provided by the top of the preload device, except for the roof layer, the floor concrete is poured layer by layer, and the applied pressure value is 50% of the design load calculated corresponding to the stage of pouring floor concrete layer by layer;

[0054] Here, after the floor concrete reaches the preset strength (about one week), the floor is pre-stressed by synchronous lifting with hydraulic jacks, so that the floor is close to the final design stress state (design loads and outer frames in each construction stage, and other forces are transmitted to the core tube), and is pre-stressed to about 50% of the total design load of the corresponding construction stage.

[0055] Preferably, the reference deformation rate can be calculated based on the vertical deformation data of the truss collected by the displacement sensor; the pressure value applied by the preloading device can be accurately controlled based on the reference deformation rate;

[0056] Step S7, closing the post-casting strips of concrete on each floor, and pouring the roofing layer concrete at one time;

[0057] Step S8, construct the secondary structure, electromechanical pipeline installation and architectural decoration on the hanging outer frame; and according to the pressure value already applied by the preloading device, the preloading device is synchronously unloaded step by step according to the corresponding applied pressure value until the construction is completed and the preloading device is finally completely unloaded.

[0058] Step S9, dismantle the pre-pressing device and fill the corresponding position of the bottom layer of the hanging outer frame with architectural decoration.

[0059] In summary, due to its special stress form and construction process, suspended structure buildings have extremely high requirements for deformation control in all aspects of construction. If they are constructed according to the conventional process, as the construction progresses, the load gradually increases, the vertical deformation of the floors continues to increase, and the concrete structure at the connection between the relevant floors and the core tube is prone to cracks and other construction quality problems, especially for the roof, which increases the risk of roof leakage, and in severe cases affects the use function.

[0060] How to avoid the vertical deformation of the concrete floor of the suspended structure and ensure the stability of the floor structure deformation during the construction process is a difficult problem that needs to be solved urgently in the construction of suspended structure buildings.

[0061] The present invention provides a method for pre-stressing the outer frame of a suspension structure, which uses a pre-stressing device such as a hydraulic jack to apply the subsequent total load in advance, so that the vertical deformation of the floor structure is pre-locked, and then the pressure is released step by step in a balanced manner as the construction load increases. It ensures that the load application and pressure release are balanced throughout the process, and the structural deformation is in a stable state.

[0062] The present invention adopts a structural pre-arching method in the early stage. After the steel structure outer frame is constructed, the subsequent design load is calculated to pre-compress the outer frame of the suspension structure to lock the vertical deformation in advance. Then, as the construction load increases, the pressure is released step by step. The outer frame structure is always in a balanced state of stress, solving the problem of increasing vertical deformation of the floor structure due to increased load during the construction of the suspended structure floor. The risk of structural cracking, roof water leakage, and damage to the building decoration layer caused by the development of vertical deformation of the floor is minimized, greatly improving the construction quality of the suspended structure.

[0063] The present invention only provides a preloading method. The floor load is borne jointly by the core tube and the hanging columns, and the load borne by the hanging columns is slightly greater than that of the core tube. The relevant preloading pressure needs to be combined with the working conditions of different projects, and relevant calculations, verification and confirmation are carried out.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A preloading method for the construction of a suspension structure, characterized in that, include: Step S1, a displacement sensor is arranged on the lower chord of the truss to collect vertical deformation data of the truss; wherein the suspension outer frame is suspended to the truss connected to the top of the core tube; Step S2, using the pre-tensioned connecting ear plate reserved at the bottom beam-column node of the suspension structure, setting the ear plate to connect with the steel corbel beam at the upper hanging point; Step S3, calculating the design load added at each construction stage of the suspension frame of the suspension floor according to the design-related parameters of the suspension frame; Step S4, arranging a preloading device connected to the foundation structure of the continuous wall at the lower part of the upper hanging point steel corbel beam, and connecting the upper hanging point steel corbel beam and the preloading device through a steel strand; Step S5, pouring floor concrete, wherein stress post-casting strips are arranged around the core tube and radiating to the corners of the hanging outer frame; Step S6, based on the calculated design load, the applied pressure value of the preloading device is calculated, and after the floor concrete reaches the preset strength; based on the applied pressure value, the floor is preloaded by synchronously lifting the preloading device; Step S7, closing the post-casting strips of concrete on each floor, and pouring the roofing layer concrete at one time; Step S8, construct the secondary structure, electromechanical pipeline installation and architectural decoration on the hanging outer frame; and according to the pressure value already applied by the preloading device, the preloading device is synchronously unloaded step by step according to the corresponding applied pressure value until the construction is completed and the preloading device is finally completely unloaded.

2. The preloading method for suspension structure construction according to claim 1, characterized in that, Step S1, comprising: The displacement sensors are arranged at the four corners of the belt truss and the ends of the cantilever truss.

3. The preloading method for suspension structure construction according to claim 1, wherein The various construction stages at least include: the pouring stage of each floor, the secondary structure stage and the building decoration stage.

4. The preloading method for suspension structure construction according to claim 1, characterized in that, Step S4 includes: Pre-stressing devices are arranged around the bottom of the suspension structure.

5. The preloading method for the construction of a suspension structure according to claim 1, characterized in that, The preloading device comprises: a hydraulic jack, a static load meter, a steel reaction beam and a steel bearing bottom beam, wherein: The steel reaction beam is connected to the foundation structure of the continuous wall through force-transmitting steel bars; One end of the hydraulic jack is against the steel reaction beam; the other end of the hydraulic jack is connected to the steel bearing bottom beam, and the steel bearing bottom beam is connected to one end of the steel strand; One end of the static load instrument is connected to the hydraulic jack, and the other end is connected to the control end to achieve interaction between the hydraulic jack and the control end.

6. The preloading method for suspension structure construction according to claim 1, characterized in that In step S6, the applied pressure value is 50% of the calculated design load corresponding to the construction stage.

7. The preloading method for suspension structure construction according to claim 1, wherein, In step S6, in order to reduce the preload provided by the preload device, except for the roof layer, the floor concrete is poured layer by layer, and the applied pressure value is 50% of the design load calculated corresponding to the stage of pouring floor concrete layer by layer.

8. The preloading method for suspension structure construction according to claim 1, characterized in that In step S6, a reference deformation rate is calculated based on the vertical deformation data of the truss collected by the displacement sensor; The pressure value applied by the pre-pressing device is controlled based on the reference deformation rate.

9. The preloading method for suspension structure construction according to claim 1, characterized in that, After step S8, the method further includes: In addition to the pre-stressing device, architectural decoration is performed on the corresponding position of the bottom layer of the hanging outer frame.

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