A rigid prestressing loading method for a two-way cantilevered support spatial steel structure system

Abstract

The present invention relates to a rigid prestressed loading method for a two-way overhang support spatial steel structure system, which belongs to the technical field of spatial steel structure buildings and solves the problem of load-bearing mode degradation of a two-way overhang support spatial steel structure system. The steel structure includes a long-direction overhang truss and a short-direction "human"-shaped two-span continuous overhang beam; the method includes: pre-tensioning the long-direction overhang truss downward at multiple points so that its displacement is consistent with its displacement under standard working conditions; installing the short-direction two-span continuous overhang beam with the pre-tensioned long-direction overhang truss as the middle support; and gradually unloading the pre-tensioning force of the long-direction overhang truss so that the short-direction two-span continuous overhang beam presents a rigid pre-tensioned stress state. This method ensures that the short-direction two-span continuous overhang beam always presents a rigid pre-tensioned stress state dominated by tension under all working conditions by presetting the vertical displacement of the long-direction overhang truss and using it as the installation state of the short-direction two-span continuous overhang beam.

Description

Technical Field

[0001] The present invention relates to the technical field of spatial steel structure buildings, and in particular to a rigid prestressed loading method for a bidirectional overhang support spatial steel structure system. Background Art

[0002] The two-way cantilever support spatial steel structure includes a long-direction cantilever truss and a short-direction "human"-shaped two-span continuous cantilever beam. The short-direction "human"-shaped two-span continuous cantilever beam uses the long-direction cantilever truss as the middle support.

[0003] Based on spatial geometric relationships, it can be seen that when a short-direction "H"-shaped two-span continuous cantilever beam is installed on the long-direction cantilever truss, that is, when the long-direction cantilever truss forms the central support, the long-direction cantilever truss undergoes vertical deformation. At this time, the short-direction "H"-shaped two-span continuous cantilever beam tends to be compressed in the longitudinal direction, thereby generating compressive stress. When the vertical deflection of the long-direction cantilever truss exceeds a certain amplitude, the compressive stress component caused by the axial compression of the short-direction "H"-shaped two-span continuous cantilever beam will exceed the tensile stress component caused by its cantilever load-bearing mode. The load mode of the short-direction "H"-shaped two-span continuous cantilever beam changes from the target tension-bending load mode (mainly tension) to the inefficient compression-bending load mode, resulting in a significant reduction in its overall load-bearing efficiency, which is a load-bearing mode degradation problem.

[0004] In the prior art, since there is no bidirectional cantilever support spatial steel structure and corresponding rigid prestressed loading method, there is no corresponding solution to the problem of load-bearing mode degradation. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a rigid prestressed loading method for a bidirectional overhang support spatial steel structure system to solve the problems of degradation of the bearing mode and reduced bearing efficiency of the bidirectional overhang support structure.

[0006] The present invention provides a rigid prestressed loading method for a bidirectional cantilevered support spatial steel structure system, wherein the bidirectional cantilevered support spatial steel structure comprises a long-direction cantilevered truss and a short-direction "H"-shaped two-span continuous cantilevered beam; the rigid prestressed loading method comprises:

[0007] Performing multi-point downward pre-tensioning on the longitudinal cantilever truss so that its displacement is consistent with its displacement under standard working conditions;

[0008] The short-direction "H"-shaped two-span continuous cantilever beam is installed using the pre-tensioned long-direction cantilever truss as a middle support;

[0009] The pre-tensioning force of the long-direction suspension truss is unloaded step by step, so that the short-direction "human"-shaped two-span continuous suspension beam is in a rigid pre-tensioned stress state.

[0010] Furthermore, when the short-direction "H"-shaped two-span continuous cantilever beam is an asymmetric structure, the multi-point downward pre-tensioning of the long-direction cantilever truss specifically includes:

[0011] Two pre-tensioning points are respectively provided at both ends of each node position at the lower part of the long-direction suspension truss, and tensioning supports are provided at corresponding positions on the ground; the node position is the connection point of two adjacent truss sections in the long-direction suspension truss;

[0012] At each of the node positions, one end of the first tensioning cable structure is connected to one of the pre-tensioning points, and the other end is connected to the tensioning support; one end of the second tensioning cable structure is connected to another of the pre-tensioning points, and the other end is connected to the tensioning support, so as to pre-tension the long-direction suspended truss downward.

[0013] Furthermore, when the short-direction "H"-shaped two-span continuous cantilever beam is a symmetrical structure, the multi-point downward pre-tensioning of the long-direction cantilever truss specifically includes:

[0014] A pre-tensioning node is set in the middle of each node position at the lower part of the long-direction suspended truss, and a tensioning support is set at the corresponding position on the ground. One end of the tensioning cable structure is connected to the pre-tensioning point, and the other end is connected to the tensioning support to pre-tension the long-direction suspended truss downward.

[0015] Furthermore, based on the vertical displacement and torsion of the long-direction suspension truss under standard working conditions, the pre-tensioning force value of each first cable structure and each second cable structure is set to ensure that the vertical displacement and torsion of the long-direction suspension truss after pre-tensioning are consistent with the vertical displacement and torsion of the long-direction suspension truss under standard working conditions.

[0016] Furthermore, the installation of the short-direction "human"-shaped two-span continuous cantilever beam includes:

[0017] Under the condition that the long direction suspension truss is kept in a downward pre-tensioned state, the short direction "human" shaped two-span continuous suspension beam is installed with the long direction suspension truss as the middle support, and a supporting structure is provided to support the short direction "human" shaped two-span continuous suspension beam, so that the dead weight of the short direction "human" shaped two-span continuous suspension beam will not act on the long direction suspension truss.

[0018] Furthermore, the step-by-step unloading of the pre-tensioning force of the longitudinal suspension truss includes: step-by-step unloading of the pre-tensioning force generated by each first tensioning cable structure and each second tensioning cable structure according to a preset ratio of the pre-tensioning force values.

[0019] Furthermore, before the longitudinal overhang trusses are pre-tensioned downward, the longitudinal overhang trusses are also pre-arched.

[0020] Furthermore, the pre-arching value of the long-direction suspension truss is determined according to the vertical deflection value and torsion of the long-direction suspension truss under standard working conditions, and then the long-direction suspension truss is pre-arched based on the pre-arching value.

[0021] Furthermore, triangular support columns are respectively provided at both ends of the long-direction suspension truss to support and fix the long-direction suspension truss.

[0022] Furthermore, the triangular support column is rigidly connected to the long-direction suspension truss.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] 1. The rigid prestressed loading method of the bidirectional cantilever support spatial steel structure system proposed in the present invention first performs multi-point downward pre-tensioning on the long-direction suspension truss to make its displacement consistent with its displacement under standard working conditions. After the short-direction "human"-shaped two-span continuous suspension beam is installed on the long-direction suspension truss (in the pre-tensioned state) and the pre-tensioning force is unloaded step by step, the bidirectional cantilever support spatial steel structure rebounds as a whole. The short-direction "human"-shaped two-span continuous suspension beam is subjected to the tensile force of the long-direction suspension truss and is stretched and lengthened as a whole to present a rigid pre-tensioned stress state, thereby avoiding the problem of load-bearing mode degradation of the short-direction "human"-shaped two-span continuous suspension beam under the influence of the vertical deflection of the long-direction suspension truss, and effectively improving the load-bearing efficiency of the short-direction "human"-shaped two-span continuous suspension beam.

[0025] 2. The rigid prestressed loading method of the bidirectional cantilever support spatial steel structure system proposed in the present invention, for the asymmetric short direction "H"-shaped two-span continuous cantilever beam structure, the present invention sets double pre-tensioning points at both ends of each node position, and takes the horizontal tension generated by the asymmetric short direction "H"-shaped two-span continuous cantilever beam structure on the long direction cantilever truss into consideration during the pre-tensioning operation, that is, the torsional effect on the long direction cantilever truss when the asymmetric short direction "H"-shaped two-span continuous cantilever beam is installed on the long direction cantilever truss is taken into consideration, thereby improving the accuracy of the rigid prestressed loading.

[0026] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0028] Figure 1 Schematic diagram of a bidirectional cantilever support spatial steel structure according to an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of a long-direction suspended truss according to an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of a two-span continuous cantilever beam in the shape of a human figure in the short direction according to an embodiment of the present invention;

[0031] Figure 4 This is a flow chart of a rigid prestressed loading method for a bidirectional overhang support spatial steel structure system according to an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of a pre-tensioned long-direction overhang truss according to an embodiment of the present invention;

[0033] Figure 6 Another schematic diagram of a pre-tensioned longitudinal overhang truss according to an embodiment of the present invention;

[0034] Figure 7 A schematic diagram of a supporting structure supporting a two-span continuous cantilever beam in a V-shaped configuration in the short direction according to an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the corresponding tension simulation after pre-tensioning the long-direction cantilever truss according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the simulation of the pre-tensioned stress on one side of a large roof with two-span continuous cantilever beams in the short direction of an embodiment of the present invention;

[0037] Figure 10 This is a simulation diagram of the pre-tensioned stress on one side of a roof of a small house with two-span continuous cantilever beams in the short direction of a "H" shape according to an embodiment of the present invention;

[0038] Figure 11 Schematic diagram of the pre-tensioned stress on one side of a large roof with two-span continuous cantilever beams in the short direction under actual working conditions of an embodiment of the present invention;

[0039] Figure 12 This is a schematic diagram of the pre-tensioned stress on one side of a small roof of a two-span continuous cantilever beam in the short direction under actual working conditions of an embodiment of the present invention.

[0040] Reference numerals:

[0041] 1-long direction overhang truss; 2-short direction "human" shaped two-span continuous overhang beam; 3-triangular support column; 4-swing column; 5-rigid connection end. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0043] In order to facilitate the understanding of the embodiment of the rigid prestressed loading method of the bidirectional overhang support spatial steel structure system, the bidirectional overhang support spatial steel structure is now described.

[0044] Specifically, such as Figure 1 As shown, the bidirectional cantilevered spatial steel structure comprises a long-direction cantilever truss 1 and a short-direction "H"-shaped two-span continuous cantilever beam 2. The short-direction "H"-shaped two-span continuous cantilever beam is connected to the long-direction cantilever truss, with the long-direction cantilever truss serving as the central support. The short-direction two-span continuous cantilever beam exhibits a structure in which the central long-direction cantilever truss, serving as the support, is raised upward, while the two side cantilever beams are recessed downward, i.e., a "H"-shaped arrangement. The short-direction cantilever beams can be symmetrical or asymmetrical.

[0045] Preferably, the long-direction hanging truss 1 is as follows Figure 2 As shown, it is a downwardly curved structure with high ends and a low center, exhibiting the properties of a typical overhang structure. The long-direction overhang truss 1 is a spatial truss, which can still withstand unbalanced horizontal forces and corresponding torque loads caused by unequal spans, unbalanced wind loads, and unfavorable live load arrangements outside the vertical plane.

[0046] The long-direction suspension truss 1 utilizes the drooping height of the architectural scheme in the main span direction to set up a suspension truss, simulating the tension / compression load-bearing mode of the cable structure / arch structure. Due to the shape-finding conditions, it is actually a tension-bending / compression-bending load-bearing mode. Specifically, its suspension bearing mode is as follows: under the control of its own weight and wind pressure, the long-direction suspension truss 1 utilizes its own height to simulate the pure tension load-bearing mode of the flexible cable structure. Taking into account the control conditions of the actual building appearance on the structural shape, the structural height control cannot fully achieve the ideal optimal state. Therefore, the actual bearing mode of the long-direction suspension truss 1 is a tension-bending load-bearing mode dominated by tension, which is a high-efficiency vertical bearing mode and can save the amount of structural materials to a large extent. Under the control of wind suction, the long-direction suspension truss 1 utilizes its own height to form a rigid compression arch structure. Taking into account the control conditions of the actual building appearance on the structural shape, the structural height control cannot fully achieve the ideal optimal state. Therefore, the actual load-bearing mode of the long-direction cantilever truss 1 is a compression-bending load-bearing mode dominated by compression, which is a high-efficiency vertical load-bearing mode and can save the amount of structural materials to a large extent.

[0047] Preferably, the short direction "human" shaped two-span continuous cantilever beam 2 is as follows Figure 3 As shown, it presents a "human" shape. The two-span continuous cantilever beam 2 has the same cantilever load-bearing mode as the long-direction cantilever truss 1. The cantilever beam structure uses the cantilever rise to simulate the tension / compression load mode of the cable / arch structure. Due to form-finding conditions, the actual load mode is tension-bending / compression-bending.

[0048] A specific embodiment of the present invention discloses a rigid prestressing loading method for a bidirectional overhang support spatial steel structure system.

[0049] Specifically, such as Figure 4 As shown, the method includes the following steps:

[0050] S110. Perform multi-point downward pre-tensioning on the long-direction overhang truss 1 so that its displacement is consistent with its displacement under the actual standard working condition. Specifically, the displacement here refers to the deformation of the long-direction overhang truss 1 under the actual overall roof standard working condition, which is the deformation caused by vertical deflection and torsion. Here, the overall roof refers to the overall roof of a building with a two-way overhang support space steel structure system as its structure. In addition, the overall roof standard working condition refers to the working condition where the two-way overhang support space steel structure is under the joint action of dead load and live load. The long-direction overhang truss 1 includes multiple truss sections, and the connection between two adjacent truss sections is a node position. Multi-point downward pre-tensioning refers to downward pre-tensioning at each node position. Specifically, in actual applications, the displacement of the long-direction overhang truss 1 under the standard working conditions of the entire roof is simulated by the finite element analysis method. However, due to the existence of objective errors such as construction in actual construction projects, there will be a certain deviation between the actual displacement of the long-direction overhang truss 1 and the displacement obtained by simulation. However, this deviation is within the allowable error range, so it can be considered that the displacement obtained by simulation is basically consistent with the actual displacement. Therefore, when the long-direction overhang truss 1 is pre-tensioned downward at multiple points, its displacement is made consistent with the displacement obtained by simulation, that is, it is basically consistent with the displacement corresponding to the actual standard working conditions, which can meet the pre-tensioning accuracy requirements.

[0051] S120. Using the pre-tensioned long-direction overhang truss 1 as the central support, install two-span short-direction "H"-shaped continuous overhang beams 2 on both sides.

[0052] S130. Gradually unload the pre-tensioning force of the long-direction suspension trusses 1, so that the short-direction "V"-shaped two-span continuous suspension beams 2 are in a rigid pre-stressed state. Specifically, after unloading the pre-tensioning force of the long-direction suspension trusses 1, the long-direction suspension trusses 1 drive the short-direction "V"-shaped two-span continuous suspension beams 2 to rebound as a whole, thereby causing the short-direction "V"-shaped two-span continuous suspension beams 2 to enter a pre-tensioned force bearing state, i.e., a pre-stressed state.

[0053] Preferably, before step S110, triangular support columns 3 are provided at both ends of the long-direction suspension truss 1 to support and secure the long-direction suspension truss 1 and effectively bear the horizontal force and torque generated by the long-direction suspension truss 1. Specifically, the triangular support columns 3 are rigidly connected to the long-direction suspension truss 1 via rigid connection ends 5, thereby ensuring effective transmission of torque from the long-direction suspension truss 1 and, to a certain extent, improving the accuracy of rigid prestressing.

[0054] Preferably, a rocking column 4 can be provided at the bottom of the long-direction overhang truss 1 to effectively reduce the span of the long-direction overhang truss 1 and significantly reduce the rigid prestressing load. Specifically, in practical applications, an excessive number of rocking columns will affect the interior space of the building and disrupt the clear load-bearing pattern of the long-direction overhang truss 1, even if the long-direction overhang truss 1 is changed from a single-span, two-end-supported structure to a multi-span continuous structure. Therefore, when setting the number of rocking columns, the layout of the interior space of the building should be prioritized, while also weighing the reduction of the rigid prestressing load.

[0055] Preferably, before step S110, based on the arrangement of the aforementioned triangular support columns 3 and the rocking columns 4, the long-direction suspension truss 7 is also pre-arched. Specifically, spatial finite element analysis software is used to analyze and calculate the vertical deflection and torsion of the long-direction suspension truss 1 under standard working conditions. The pre-arch value of the long-direction suspension truss 1 is set in the opposite direction according to the vertical deflection and torsion, and the pre-arch is performed according to the pre-arch value, so that under standard working conditions, the vertical deflection and torsion generated above can be eliminated and the truss is kept in the standard position, thereby effectively improving the accuracy of rigid prestressing. The standard position refers to the position that the long-direction suspension truss 1 should be in under standard working conditions, which is designed according to the design indicators of the bidirectional suspension support spatial steel structure system, that is, the position before pre-arching.

[0056] Preferably, in step S110, the long-direction suspension truss 1 is pre-tensioned to simulate the vertical deformation and torsion of the long-direction suspension truss 1 when it serves as the middle support of the short-direction "H"-shaped two-span continuous suspension beam 2. While maintaining the deformation and torsion, the short-direction "H"-shaped two-span continuous suspension beam 2 is installed. When the pre-tensioning force is unloaded step by step, the short-direction "H"-shaped two-span continuous suspension beam 2 rebounds with the long-direction suspension truss 1, that is, a rigid prestressed tension is applied to the short-direction "H"-shaped two-span continuous suspension beam 2, so that it maintains an efficient tension-dominated tension-bending load-bearing mode.

[0057] Specifically, when the short-direction "H"-shaped two-span continuous cantilever beam 2 is an asymmetric structure, the long-direction cantilever truss 1 is pre-tensioned downward at multiple points in the following manner:

[0058] Taking into account that the horizontal tension generated by the asymmetric short-direction "H"-shaped two-span continuous cantilever beam 2 on both sides of the long-direction suspension truss 1 is different in magnitude, which will cause a certain degree of torsion in the long-direction suspension truss 1, two pre-tensioning points are respectively set at both ends of each node position in the lower part of the long-direction suspension truss 1. The node position is the connection point of two adjacent truss sections in the long-direction suspension truss 1. In addition, tensioning supports are set at corresponding positions on the ground; for example, the two pre-tensioning points at each node position correspond to a tensioning support on the ground, and the tensioning support is located directly below the truss section in the long-direction suspension truss 1. Preferably, in order to facilitate construction, four tensioning nodes at adjacent node positions can share a tensioning support, which also saves construction costs to a certain extent.

[0059] Preferably, the long-direction suspension truss 1 is pre-tensioned by a tensioning cable structure, and tension is applied to the two pre-tensioning points at the node positions by the first tensioning cable structure and the second tensioning cable structure respectively. Specifically, at each node position, one end of the first tensioning cable structure is connected to one of the pre-tensioning points, and the other end is connected to the tensioning support; one end of the second tensioning cable structure is connected to another pre-tensioning point, and the other end is connected to the tensioning support, so as to pre-tension the long-direction suspension truss 1 downward. The long-direction suspension truss 1 after pre-tensioning is as shown in FIG. Figure 5 shown.

[0060] Preferably, the pre-tensioning force values ​​of each first and second tensioning cable structures are set based on the vertical displacement and torsion of the long-direction suspension truss 1 under standard operating conditions to ensure that the vertical displacement and torsion of the long-direction suspension truss 1 after pre-tensioning are consistent with the vertical displacement and torsion of the long-direction suspension truss 1 under standard operating conditions. Specifically, the force generated by each tensioning cable structure can be individually controlled. In practical applications, spatial finite element analysis software is used to calculate the tension of each tensioning cable structure by given the vertical deflection, torsion, pre-tensioning point, and the position of the tensioning support of the long-direction suspension truss 1. Based on the obtained tension of each tensioning cable structure, in actual construction projects, pre-tensioning is performed by controlling the tension of the tensioning cable structure to produce a corresponding displacement of the long-direction suspension truss 1. Specifically, a tension sensor is installed near the tensioning support of each tensioning cable structure, and the tension of the corresponding tensioning cable structure is adjusted according to the displayed value of the tension sensor to produce a target tension. This method can improve the accuracy of rigid prestressing loading.

[0061] Preferably, in practical applications, displacement sensors can be installed at the pre-tensioning points of the long-direction suspension trusses. Pre-tensioning can be achieved by adjusting the tension of each cable structure so that the displacement indicated by the displacement sensor matches the target displacement. The target displacement refers to the displacement of the long-direction suspension trusses 1 under standard working conditions. This method is simple to operate, but the accuracy of rigid prestressing is lower than that of the previous method.

[0062] Preferably, when the short-direction "H"-shaped two-span continuous cantilever beam 2 is a symmetrical structure, the long-direction cantilever truss 1 is pre-tensioned downward at multiple points in the following manner:

[0063] like Figure 6 As shown, a pre-tensioning node is provided at the midpoint of each node position at the bottom of the long-direction overhang truss 1, and a tensioning support is provided at a corresponding position on the ground. At each node position, one end of a tensioning cable structure is connected to the pre-tensioning point, and the other end is connected to the tensioning support to pre-tension the long-direction overhang truss 1 downward. Because the short-direction "V"-shaped two-span continuous overhang beam 2 is a symmetrical structure, no corresponding torsion occurs when connected to the long-direction overhang truss, making the pre-tensioning process simpler. However, the same principles as the asymmetric structure can be used to calculate the tension of each tensioning cable structure and perform pre-tensioning.

[0064] Preferably, in step S120, the short-direction "H"-shaped two-span continuous cantilever beam 2 is installed specifically by the following method:

[0065] Under the working condition that the long-direction suspension truss 1 is kept in the downward pre-tensioned state, the short-direction "human" shaped two-span continuous suspension beam 2 is installed with the long-direction suspension truss 1 as the middle support. In order to prevent the self-weight of the short-direction "human" shaped two-span continuous suspension beam 2 from affecting the vertical deformation of the long-direction suspension truss 1, a supporting structure is set up to support the short-direction "human" shaped two-span continuous suspension beam 2 during the installation process. For example, Figure 7 As shown, a stiffening cable is installed as a supporting structure to temporarily support the two-span continuous cantilever beam 1 in the "H" shape in the short direction.

[0066] Preferably, in step S130, during the unloading of the pre-tensioning force, in order to ensure the stable rebound of the long-direction cantilever truss 1 and not cause damage to the bidirectional cantilever support spatial steel structure, a step-by-step unloading method is adopted. Specifically, the pre-tensioning force generated by each first cable structure and each second cable structure is unloaded step by step according to a preset ratio of their pre-tensioning force values. For example, the pre-tensioning force value generated by each first cable structure is 200kN, and the pre-tensioning force value generated by each second cable structure is 450kN. If the pre-tensioning force is unloaded step by step at a ratio of 10%, then after the first-level unloading, the pre-tensioning force value corresponding to each first cable structure is 180kN, and the pre-tensioning force value corresponding to each second cable structure is 405kN. And so on, the unloading is carried out step by step.

[0067] The beneficial effects of the rigid prestressing loading method for the bidirectional overhang support spatial steel structure system proposed by the present invention are further illustrated by the following examples:

[0068] Specifically, for the asymmetric short-direction "H"-shaped two-span continuous cantilever beam 2, the rigid prestressed loading method of the bidirectional cantilever support spatial steel structure system was simulated using spatial finite element analysis software.

[0069] The corresponding tension after pre-tensioning the long-direction suspended truss 1 is as follows: Figure 8 As shown in the figure, it can be seen that the tension applied to each pre-tensioning point on one side of the long-direction overhang truss 1 is 200kN, and the tension applied to each pre-tensioning point on the other side is 450kN; the vertical deflection corresponding to the long-direction overhang truss 1 close to the large roof side (i.e., the larger span of the short-direction "human"-shaped two-span continuous overhang beam 2) is 306mm downward; the vertical deflection corresponding to the long-direction overhang truss 1 close to the small roof side (i.e., the smaller span of the short-direction "human"-shaped two-span continuous overhang beam 2) is 157mm downward.

[0070] After installing the short-direction "H"-shaped two-span continuous cantilever beam 2 and gradually unloading the pre-tensioning force, the long-direction cantilever truss 1 near the large roof side vertically deformed and rebounded, and the vertical deflection became 236mm downward; the long-direction cantilever truss 1 near the small roof side vertically deformed and rebounded, and the vertical deflection became 114mm downward; the short-direction "H"-shaped two-span continuous cantilever beam 2 near the large roof side vertically arched 72mm upward; the short-direction "H"-shaped two-span continuous cantilever beam 2 near the small roof side vertically arched 43mm upward; the pre-tensioning stress (unit: kN) of the short-direction "H"-shaped two-span continuous cantilever beam 2 on the large roof side is as follows Figure 9 As shown in the figure, the pre-tension stress (unit: kN) of the two-span continuous cantilever beam of the “H” shape in the short direction on one side of the small roof is as follows: Figure 10 shown.

[0071] Under normal use of the roof (bidirectional cantilever support space steel structure) load loading condition, that is, the actual project summary, the vertical deflection of the long-direction cantilever truss 1 close to the large roof side is 312mm, which is basically consistent with the vertical deflection of 306mm in the pre-tensioning stage. The vertical deflection of the long-direction cantilever truss 1 close to the small roof side is 141mm downward, which is basically consistent with the vertical deflection of 157mm in the pre-tensioning stage. The pre-tension stress (unit: kN) of the short-direction "human" shaped two-span continuous cantilever beam 2 on the large roof side is as follows Figure 11 As shown, compared with the simulation stage ( Figure 9 ), the pre-tensioned stress is reduced, but still maintains a considerable level, within the allowable range of the high-efficiency load-bearing mode. The pre-tensioned stress (unit: kN) of the two-span continuous cantilever beam of the “H” shape in the short direction on one side of the small roof is as follows: Figure 12 As shown, compared with the simulation stage ( Figure 10 ), the pre-tension stress is reduced, but still maintains a considerable level, within the allowable range of the high-efficiency load-bearing mode.

[0072] Based on the above analysis, it is proved that the rigid prestressed loading method proposed in the present invention can well solve the problem of the degradation of the bearing mode of the two-span "H"-shaped continuous cantilever beam 2 in the short direction, and effectively ensure that the two-span "H"-shaped continuous cantilever beam 2 in the short direction is mainly subjected to tension and bending.

[0073] Compared with the prior art, the rigid prestressed loading method of the bidirectional cantilever support spatial steel structure system proposed in the present invention first performs multi-point downward pre-stressing on the long-direction suspension truss to make its displacement consistent with its displacement under the standard working condition of the overall roof. When the short-direction "human"-shaped two-span continuous suspension beam is installed on the long-direction suspension truss (in the pre-stressed state) and the pre-stressing force is unloaded step by step, the bidirectional cantilever support spatial steel structure rebounds as a whole, wherein the short-direction "human"-shaped two-span continuous suspension beam is subjected to the tensile force of the long-direction suspension truss and is stretched and lengthened as a whole to present a rigid pre-stressed state, avoiding the problem of load-bearing mode degradation of the short-direction "human"-shaped two-span continuous suspension beam under the influence of the vertical deflection of the long-direction suspension truss, and effectively improving the load-bearing efficiency of the short-direction "human"-shaped two-span continuous suspension beam. Secondly, for the asymmetric short direction "H"-shaped two-span continuous suspension beam structure, the present invention sets double pre-tensioning points at both ends of each node position, and takes into account the horizontal tension generated by the asymmetric short direction "H"-shaped two-span continuous suspension beam structure on the long direction suspension truss during the pre-tensioning operation, that is, the torsional effect on the long direction suspension truss when the asymmetric short direction "H"-shaped two-span continuous suspension beam is installed on the long direction suspension truss is taken into account, thereby improving the accuracy of rigid prestressed loading.

[0074] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0075] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A rigid prestressing loading method for a bidirectional overhang support spatial steel structure system, characterized in that: The bidirectional cantilever support spatial steel structure comprises a long-direction cantilever truss and a short-direction "human"-shaped two-span continuous cantilever beam; the short-direction "human"-shaped two-span continuous cantilever beam is connected to the long-direction cantilever truss, with the long-direction cantilever truss serving as the middle support; The rigid prestressed loading method comprises: Performing multi-point downward pre-tensioning on the longitudinal cantilever truss so that its displacement is consistent with its displacement under standard working conditions; The short-direction "H"-shaped two-span continuous cantilever beam is installed with the long-direction cantilever truss as the middle support; The pre-tensioning force of the long-direction suspension truss is unloaded step by step, so that the short-direction "human"-shaped two-span continuous suspension beam is in a rigid pre-tensioned stress state.

2. The rigid prestressing loading method of the bidirectional overhang support spatial steel structure system according to claim 1 is characterized in that: When the short-direction "H"-shaped two-span continuous cantilever beam is an asymmetric structure, the multi-point downward pre-tensioning of the long-direction cantilever truss specifically includes: Two pre-tensioning points are respectively provided at both ends of each node position at the lower part of the long-direction suspension truss, and tensioning supports are provided at corresponding positions on the ground; the node position is the connection point of two adjacent truss sections in the long-direction suspension truss; At each of the node positions, one end of the first tensioning cable structure is connected to one of the pre-tensioning points, and the other end is connected to the tensioning support; one end of the second tensioning cable structure is connected to another of the pre-tensioning points, and the other end is connected to the tensioning support, so as to pre-tension the long-direction suspended truss downward.

3. The rigid prestressing loading method of the bidirectional overhang support spatial steel structure system according to claim 2 is characterized in that: When the short-direction "H"-shaped two-span continuous cantilever beam is a symmetrical structure, the multi-point downward pre-tensioning of the long-direction cantilever truss specifically includes: A pre-tensioning node is set in the middle of each node position at the lower part of the long-direction suspended truss, and a tensioning support is set at the corresponding position on the ground. One end of the tensioning cable structure is connected to the pre-tensioning point, and the other end is connected to the tensioning support to pre-tension the long-direction suspended truss downward.

4. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 2 is characterized in that: According to the vertical displacement and torsion of the long-direction suspension truss under standard working conditions, the pre-tensioning force value of each first cable structure and each second cable structure is set to ensure that the vertical displacement and torsion of the long-direction suspension truss after pre-tensioning are consistent with the vertical displacement and torsion of the long-direction suspension truss under standard working conditions.

5. The rigid prestressing loading method of the bidirectional overhang support spatial steel structure system according to claim 1 or 2, characterized in that: The installation of the short-direction "human"-shaped two-span continuous cantilever beam includes: Under the working condition that the long direction suspension truss is kept in a downward pre-tensioned state, the short direction "human" shaped two-span continuous suspension beam is installed with the long direction suspension truss as the middle support, and a supporting structure is provided to support the short direction "human" shaped two-span continuous suspension beam, so that the dead weight of the short direction "human" shaped two-span continuous suspension beam will not act on the long direction suspension truss.

6. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 2 is characterized in that: The stepwise unloading of the pre-tensioning force of the longitudinal suspension truss includes: stepwise unloading of the pre-tensioning force generated by each first tensioning cable structure and each second tensioning cable structure according to a preset ratio of the pre-tensioning force values.

7. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 2 is characterized in that: Before the longitudinal overhanging trusses are pre-tensioned downward, the longitudinal overhanging trusses are also pre-arched.

8. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 7 is characterized in that: The pre-camber value of the long-direction suspension truss is determined according to the vertical deflection value and the torsion of the long-direction suspension truss under standard working conditions, and the long-direction suspension truss is pre-cambered based on the pre-camber value.

9. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 7, characterized in that: It also includes triangular support columns respectively arranged at both ends of the long-direction suspension truss to support and fix the long-direction suspension truss.

10. The rigid prestressing loading method for a bidirectional overhang support spatial steel structure system according to claim 9, characterized in that: The triangular support column is rigidly connected to the long-direction suspension truss.

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