Strengthening method for high turnover of climbing tower crane in narrow core tube

Abstract

The application discloses a high turnover reinforcing method for a tower crane in a narrow core tube, and particularly relates to the technical field of building construction, and the reinforcing steps are as follows: S1, tower crane climbing planning: confirming the design tower crane climbing times according to the to-be-built height of a high-rise building and the height of the inner climbing tower crane; S2, the tower crane reinforcing adopts a working mode of shearing force wall and surrounding frame beam collaborative force bearing; S2.1, B1 layer tower crane reinforcing: connecting one end of a tower crane tool beam with a shearing force wall of the building, and placing the other end on a surrounding frame beam; S2.2, B2 to Bn layer tower crane reinforcing. The application proposes a tower crane arrangement mode of core tube shearing force wall and surrounding structure beam collaborative force bearing. Based on the arrangement mode, it is found that the existing structure cannot bear the tower crane load, and needs to be reinforced. Therefore, the reinforcing method of "only needing to reinforce one side of the shearing force wall and exempting the other side of the frame beam from reinforcement, and high turnover of components" is proposed by comprehensively considering the construction efficiency and economic benefits, and has strong operability and economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building construction, more particularly, the present application relates to a high turnover reinforcing method for an inner climbing tower crane in a narrow core tube. BACKGROUND

[0002] In order to adapt to the changing structure form due to the development of the times, the inner climbing tower crane often has multiple models to choose from. From the climbing way, there are six kinds of inner climbing tower cranes, which are mechanical rope wheel type, whole external hanging type, frame side top type, sleeve climbing ladder type, double tower top type and frame steel column type. In actual construction, the inner climbing tower crane suitable for the actual engineering is selected according to the structure form and stress characteristics of the main structure of the construction site, and the safety, economy, quality and progress are comprehensively considered. Unlike the common attached tower crane in construction, the inner climbing tower crane is usually installed inside the main structure, such as the elevator room, stairwell or other specially set bays according to the size of the tower crane, and its construction range is a whole circle with the center of rotation as the center, and the tower body that can freely climb meets the construction needs of modern high-rise and super high-rise buildings.

[0003] The inner climbing crane will produce significant construction load and apply to the building main structure during the construction process. In the construction process, the inner climbing tower crane needs to be installed on the building structure and produce a large construction load during use. Generally, the inner climbing tower crane is usually arranged inside the core tube and climbs, however, the core tube size of a certain super high-rise tower studied in the present application is only 6.1m*3.3m, and the tube body is very narrow, so the conventional arrangement method cannot meet the construction demand; the conventional attached form of the inner climbing tower crane is completely attached to the building core tube, and the size of the core tube is usually large, which is convenient for reinforcement; however, for some narrow core tubes, the size is limited and the internal space is narrow, and the reasonable arrangement of the inner climbing tower crane in such buildings still needs to be improved. In addition, due to the large construction load of the tower crane, the structure attached to the tower crane often needs to be reinforced in engineering, and the current common reinforcement method is to reinforce the structure itself, which is single in form and the upper limit of the reinforcement capacity is limited by the size of the existing structure (such as the size of the concrete beam section limits the upper limit of the reinforcement amount), so a reinforcement measure with higher reinforcement capacity and more flexible operation is urgently needed. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a high turnover reinforcing method for an inner climbing tower crane in a narrow core tube, and the technical problem to be solved by the present application is how to solve the problem that the conventional arrangement method cannot meet the demand of the inner climbing tower crane installed on the building structure to produce a large construction load.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a high turnover reinforcing method for an inner climbing tower crane in a narrow core tube, and the specific reinforcing steps are as follows:

[0006] S1, tower climbing planning: according to the height of the high-rise building to be built and the height of the inner climbing tower, the design tower climbing times are confirmed, and from bottom to top, they are named as B1, B2, …, Bn, wherein n is the tower climbing times;

[0007] S2, tower reinforcement adopts the working mode of shear wall and surrounding frame beam collaborative force;

[0008] S2.1, B1 tower reinforcement: one end of the tower tool beam is connected with the shear wall of the building, and the other end is placed on the surrounding frame beam;

[0009] S2.2, B2 to Bn tower reinforcement: in the process of subsequent climbing, the shear wall and the structural beam jointly bear the tower load;

[0010] S3, reinforcement design;

[0011] S3.1, overall design of reinforcement mode: reinforcing bars are added in the structure on one side of the shear wall; an "eight" brace is arranged on one side of the frame beam, one end of the "eight" brace is connected with the lower surface of the structural beam, and the other end is connected with the inner side of the cylinder; connected with the two ends of the shear wall are two cylinders containing circular steel pipes, and the two ends of the "eight" brace are connected with the structure in a hinged manner;

[0012] S3.2, design of "eight" brace and accessory components: due to different floor heights at different heights and different length requirements of the "eight" brace, the "eight" brace steel pipes are uniformly designed in the form of "reference modulus + adjustment modulus".

[0013] In a preferred embodiment, the height of the high-rise building to be built in S1 includes but is not limited to the height of the basement, and the naming number of B1 to Bn is matched with the set floor height, for example, B1 corresponds to -1 floor, B2 corresponds to 3 floor, and so on, which facilitates subsequent confirmation of the installation bottom number of the tower crane.

[0014] In a preferred embodiment, the "reference modulus + adjustment modulus" in step S3.2 is the reference modulus length of the "eight" brace, and the adjustment modulus is different adjustment length.

[0015] In a preferred embodiment, the reference modulus and the adjustment modulus can be recycled, and only the end plate cannot be recycled, which greatly increases the recycling efficiency and reduces material waste.

[0016] In a preferred embodiment, tower crane construction load analysis is performed before step S3, and whether component reinforcement is needed is determined according to the "Unified Standard for Reliability Design of Building Structures" (GB50068-2018).

[0017] In a preferred embodiment, the flange plate connecting piece is made at the connection node between the two ends of the eight-shaped support and the cylinder.

[0018] Technical effects and advantages of the present application:

[0019] The present application proposes a tower crane arrangement mode of core tube shear wall and peripheral structure beam collaborative force, based on the arrangement mode, it is found that the existing structure cannot bear the tower crane load and needs to be reinforced, therefore, considering the construction efficiency and economic benefits, a reinforcement method of "structure without reinforcement, component high turnover" is proposed, which has strong operability and economy. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of tower crane force analysis based on ANSYS of the present application.

[0021] Figure 2 It is a schematic diagram of 8 directions of tower crane load calculation of the present application.

[0022] Figure 3 It is a calculation diagram of portal frame of the present application.

[0023] Figure 4 It is a calculation diagram of portal frame based on "eight" shaped support of the present application.

[0024] Figure 5 It is a schematic diagram of structural bending moment distribution (kN m) of 23F when the "eight" shaped support is not set of the present application.

[0025] Figure 6 It is a schematic diagram of structural bending moment distribution (kN m) of 23F when the "eight" shaped support is set of the present application.

[0026] Figure 7 It is a schematic diagram of structural axial force distribution (kN) of 23F when the "eight" shaped support is set of the present application.

[0027] Figure 8 It is an eight-shaped support reinforced beam design drawing of the present application.

[0028] Figure 9 It is a connection node schematic diagram of eight-shaped support and cylinder of the present application.

[0029] Figure 10 It is a flange plate design schematic diagram of both sides of eight-shaped support of the present application.

[0030] Figure 11 It is a schematic diagram of eight-shaped support in the tower crane load application area of the present application.

[0031] Figure 12 It is a schematic diagram of eight-shaped support outside the tower crane load application area of the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0033] The present application provides a narrow core tube inner climbing tower crane high turnover reinforcement method, and the specific reinforcement steps are as follows:

[0034] S1, tower crane climbing planning: according to the height of the high-rise building to be built and the height of the inner climbing tower crane, the design tower crane climbing times are confirmed, and they are named from bottom to top as B1, B2, …, Bn, wherein n is the tower crane climbing times;

[0035] S2, tower crane reinforcement adopts the working mode of shear wall and surrounding frame beam collaborative force;

[0036] S2.1, B1 layer tower crane reinforcement: one end of the tower crane tool beam is connected with the shear wall of the building, and the other end is placed on the surrounding frame beam;

[0037] S2.2, B2 to Bn layer tower crane reinforcement: in the process of subsequent climbing, the shear wall and the structural beam jointly bear the tower crane load;

[0038] S3, reinforcement design;

[0039] S3.1, overall design of reinforcement mode: reinforcing bars are increased in the structure on one side of the shear wall; an "eight" brace is arranged on one side of the frame beam, one end of the "eight" brace is connected with the lower surface of the structural beam, and the other end is connected with the inner side of the cylinder; connected with the two ends of the shear wall are two cylinders containing circular steel pipes, and the two ends of the "eight" brace are connected with the structure in a hinged manner;

[0040] S3.2, design of "eight" brace and accessory components: due to different floor heights at different heights and different length requirements of the "eight" brace, the "eight" brace steel pipes uniformly adopt the mode of "reference modulus + adjustment modulus".

[0041] The embodiment is specifically:

[0042] Narrow core tube tower crane arrangement:

[0043] A super high-rise building is composed of four interconnected towers, with a maximum height of 199.75 meters; the highest 38 floors above ground, 4 floors below ground; among them, the land area is about 18,000 square meters, the total building area is about 244,000 square meters, the above-ground building area is about 185,000 square meters, and the basement building area is about 66,800 square meters; the T3 tower of the super high-rise building is a frame-core tube structure; according to the engineering needs, a ZSL850 internal climbing tower crane needs to be arranged in the T3 tower, the total height of the T3 tower is 130m, and the tower crane needs to climb 6 times, with the bottom base respectively placed on B1F, 3F, 7F, 11F, 15F, 19F and 23F;

[0044] However, the internal dimensions of the T3 tower core tube (stairwell core tube) are very narrow, with a local size of only 6.1m x 3.3m, and it is impossible to arrange an internal climbing tower crane in the core tube according to the general method; in order to meet the subsequent climbing needs of the tower crane, the present application proposes a working mode of collaborative force of shear wall and surrounding frame beam: one end of the tower crane tool beam is connected with the shear wall of the core tube, and the other end is placed on the surrounding frame beam; in the process of subsequent climbing, the shear wall and the structural beam jointly bear the tower crane load; among them, at B1 floor, the tool beam is connected with the concrete beam on the north side, and at other floors, the tool beam is connected with the steel beam on the north side; through this overall arrangement mode, the problem of being unable to arrange the internal climbing tower crane in the core tube is solved;

[0045] Tower crane construction load analysis

[0046] In order to determine the safety of the structure, the construction load of the internal climbing tower crane ZSL850 should be analyzed first; according to the "Unified Standard for Reliability Design of Building Structures" (GB50068-2018), the safety factor of the tower crane dynamic load is 1.5, the safety factor of the tower crane static load is 1.3, and the load value is taken according to Table 1, wherein R1 and R2 are the horizontal forces in two orthogonal directions;

[0047] Table 1 ZSL850 load value table

[0048]

[0049]

[0050] As shown in Figure 1 , based on a general finite element software for tower crane stress analysis, nodes 561 and 437 represent the nodes where the tool beam is connected with the structural shear wall, and nodes 503 and 379 represent the nodes where the tool beam is connected with the concrete structural beam; in order to fully consider the load generated when the ZSL850 tower crane acts in different directions, the external force is taken according to Figure 2Load is applied in 8 directions as shown, and the envelope reaction is taken as the final design value of the structure, and the relevant calculation results are shown in Table 2; from Table 2, it can be seen that the load generated by the tower crane is very significant, and the vertical concentrated load applied to the structure at the beam end of the north side can reach 937.2kN, at the same time, the north side beam span is 14m, and the concentrated load will also generate significant beam bending moment internal force; after calculation and review, the existing structure cannot meet the bearing requirement, so component reinforcement is needed, which is also the main research point of the present application;

[0051] Table 2: Envelope value of steel beam structure node reaction under eight working conditions (unit: t)

[0052]

[0053] At B1F layer, the size of the tool beam north side concrete beam is 700*1000, and the concrete grade is C35; connected with the north side concrete beam at both ends are two cylindrical columns containing circular steel pipes, the outer diameter of the cylindrical column is 1400mm, the diameter of the circular steel pipe is 1100mm, the thickness of the circular steel pipe is 30mm, and the concrete grade inside and outside the circular steel pipe is C60;

[0054] Based on the PKPM structure stress analysis software, the above engineering stress is simplified as a portal frame as shown in Figure 3 , in which, for safety consideration, the bearing action of the outer concrete of the two side circular steel pipes is not considered in modeling, and vertical concentrated force 937kN is applied at nodes ② and ③; it is found through analysis that the stress ratio of the concrete beam cannot meet the structure design requirement, the bending moment at the left end of the beam reaches 3329kNm, the shear force reaches 1232kN, the bending moment at the right end of the beam reaches 2863.4kNm, and the shear force reaches 888kN, and only by increasing the beam reinforcement can the stress requirement be met, and additional reinforcement measures need to be taken;

[0055] Therefore, a reinforcement method that the structure itself is not reinforced and the components can be recycled is proposed, as shown in Figure 4As shown, the "eight" shaped support is arranged near the load action point of the inner climbing tower crane, and the support is connected with the round steel pipe column foot and the concrete beam bottom respectively. The support adopts round steel pipe section, the section outer diameter is 250 mm, and the wall thickness is 18 mm. The layer height is calculated according to 4200 mm. Through analysis, under the action of the eight-shaped support, the bending moment internal force generated by the concrete beam under the load of the inner climbing tower crane is reduced to 990.1 kN m (left side) and 993.7 kN m (right side) respectively, which is only about 29.8% of the original beam internal bending moment value. The maximum shear force in the beam is reduced to 353 kN, which is only about 28.6% of the original beam internal shear force value. Since the two ends of the eight-shaped support will be connected with the structure in a hinged manner, it will not generate bending moment and shear force, and only bear axial internal force, and the maximum value of the internal force is about 1207 kN. Through calculation and review, after adding the eight-shaped support, the concrete beam can be constructed according to the original design reinforcement, without additional reinforcement, and the structure itself is not required to be reinforced.

[0056] With the increase of building height, the size of the structure beam and column will be further reduced for the consideration of structural stress optimization. At the 23F, the structure beam changes from the 700*1000 concrete beam of B1 layer to the 250*600 H-shaped steel beam, and the structure column connected with the both ends of the beam changes from the 1400 mm diameter to the 400 mm diameter steel column. For the reinforcement effect of 23F, it is found through analysis that when the eight-shaped support is not added, the bending moment at both ends of the beam reaches 2386.4 kN, and the mid-span bending moment reaches 2810.6 kN, and the stress ratio far exceeds the structural design requirement (such as Figure 5 As shown). After adding the eight-shaped support, the reinforcement effect is more obvious than that of B1 layer working condition. The bending moment at both ends of the beam is 43.3 kN m, which is only 2% of the original structure beam stress, and the maximum bending moment at the mid-span is 311.4 kN m, which is only 11.8% of the original structure.

[0057] It is found through research that the reason for the above phenomenon is that the stiffness ratio of the structure beam and column changes significantly with the change of the section form and size, and the distribution of internal force in the whole frame under external load is also significantly different from that of B1 layer. The diameter of the eight-shaped support is 250 mm, which has no obvious difference with the diameter of the structure column (400 mm). At this time, the eight-shaped support directly arranged at the beam bottom corresponding to the load application point can divide larger internal force (such as Figure 7 As shown, the axial force is mainly distributed on the eight-shaped support), thereby significantly weakening the stress of the structure column.

[0058] Design of eight-shaped support and accessory components

[0059] As shown, the eight-shaped support is arranged near the load action point of the inner climbing tower crane, and the support is connected with the round steel pipe column foot and the concrete beam bottom respectively. The support adopts round steel pipe section, the section outer diameter is 250 mm, and the wall thickness is 18 mm. The layer height is calculated according to 4200 mm. Through analysis, under the action of the eight-shaped support, the bending moment internal force generated by the concrete beam under the load of the inner climbing tower crane is reduced to 990.1 kN m (left side) and 993.7 kN m (right side) respectively, which is only about 29.8% of the original beam internal bending moment value. The maximum shear force in the beam is reduced to 353 kN, which is only about 28.6% of the original beam internal shear force value. Since the two ends of the eight-shaped support will be connected with the structure in a hinged manner, it will not generate bending moment and shear force, and only bear axial internal force, and the maximum value of the internal force is about 1207 kN. Through calculation and review, after adding the eight-shaped support, the concrete beam can be constructed according to the original design reinforcement, without additional reinforcement, and the structure itself is not required to be reinforced. Figure 8As shown, it is the design drawing of the tower crane eight-shaped support reinforcement. According to the climbing requirements of the inner climbing tower crane, a total of 6 times of climbing will be generated within the height range of the super high-rise structure. Due to the different floor heights at different heights and the different length requirements of the eight-shaped support, in order to improve the turnover rate, the eight-shaped support steel pipes are uniformly adopted in the form of "reference modulus + adjustment modulus", that is, the reference modulus length of the eight-shaped support is 4.5 m, and the adjustment modulus is 1 m and 2 m. According to the different length requirements of each floor, different modulus matching methods are selected. Through this method, in the 6 times of climbing, only 6 pieces, 1 piece and 3 pieces of support with lengths of 4500 mm, 2000 mm and 1000 mm need to be processed, which greatly increases the turnover of the eight-shaped support pipes;

[0060] As shown in Figure 9 , at the connection node of the eight-shaped support pipe and the cylinder, a flange plate connecting piece is made, one end of which is connected with the flange plate at the end of the eight-shaped support through the flange plate, and the other end is connected with the round steel column through the full penetration welding, as shown in Figures 8-9 , in order to prevent local buckling of the connecting plate, the column outer web is welded at the part of the connecting plate not extending into the concrete of the cylinder, and at the same time, in order to ensure that it does not affect the compactness of the concrete pouring of the two side cylinders, the web at B1 layer does not extend into the interior of the concrete of the cylinder; the flange plate at the end of the eight-shaped support is designed as shown in Figure 10 , stiffening ribs are arranged at equal angles along the flange plate to prevent buckling deformation of the flange plate during loading; at the position where the eight-shaped support is connected with the bottom of the concrete beam, a steel plate embedded part is embedded in the beam bottom, and the eight-shaped support is welded and connected therewith, and the node form is similar to Figure 9 ;

[0061] It is worth noting that for the H-shaped steel beam of 3 layers and above, in order to prevent local buckling, according to the two ways of "eight" shaped support stress points in the tower crane load application point area and outside the area, the stiffening rib construction method is proposed, which further improves the force transmission reliability;

[0062] It is worth noting that through the proposed reinforcement method, the size of the structure itself is avoided to be increased or the reinforcement is avoided to be increased, and the non-turnover component is only a small size embedded part at the column side or the beam bottom, while the eight-shaped support round steel pipe as the main force component can be used in the process of each climbing of the inner climbing tower crane, and the more the turnover times, the more prominent the economic benefits, which achieves the reinforcement goal of "structure itself without reinforcement and high turnover of components".

[0063] In summary, according to the special working condition of the narrow core tube of a super high-rise building, the planar arrangement method of the climbing tower crane is discussed according to the construction requirements, and the structure reinforcement is analyzed, and the main conclusions are as follows:

[0064] 1) when the core tube internal size is too narrow, the tower machine can be placed on the tool beam, one end of the tool beam is connected with the core tube shear wall, and one end can be connected with the frame beam structure around the core tube (placed on the structure beam), at this time, the structure beam mainly bears the significant vertical construction load;

[0065] 2) the eight-shaped bracing reinforcement method can effectively reinforce the concrete beam, under the action of the eight-shaped bracing, the internal bending moment of the B1 layer concrete beam can be reduced to 29.8% of the original bending moment, and the internal shear force can be reduced to 28.6% of the original bending moment; the stress sharing effect is more obvious for the upper steel beam, after reinforcement, the end stress of the 23F structure beam is only 2% of the original structure beam, and the maximum bending moment in the middle of the span is only 11.8% of the original structure;

[0066] 3) the application proposes the processing method of the eight-shaped bracing “reference modulus + adjustment modulus”, which guarantees the recyclability of the eight-shaped bracing as the main stressed component, and the more the recycling times are, the more prominent the economic benefits are; the eight-shaped bracing reinforcement method only needs to reinforce the structure on one side of the shear wall, and the structure on one side of the frame beam is “structure free reinforcement”, which can avoid repeated reinforcement of the original structure.

[0067] The reinforcement method proposed in the application realizes the target of “partial structure itself free reinforcement, and component recyclability”, meets the working requirements of the internal climbing tower machine near the narrow core tube, and the construction method and related conclusions have great reference or guiding significance for similar projects.

[0068] Finally, it should be pointed out that, in the description of the application, it should be pointed out that, unless otherwise specified and limited, the terms “installation”, “connection” and “connection” should be understood broadly, which can be mechanical connection or electrical connection, or the communication between two elements, or direct connection, “up”, “down”, “left”, “right” and the like are only used to represent the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change;

[0069] Secondly: the application discloses the embodiment in the drawing, only the structure related to the embodiment is involved, other structures can be referred to the general design, and under the condition of no conflict, the same embodiment and different embodiments of the application can be combined with each other;

[0070] Finally: the above only describes the preferred embodiments of the application, and is not used to limit the application, and any modification, equivalent replacement, improvement and the like made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method for reinforcing a high turnover of climbing tower cranes in narrow core tubes, characterized in that: The specific reinforcement steps are as follows: S1, tower climbing planning: according to the height of the high-rise building to be built and the height of the inner climbing tower, the design tower climbing times are confirmed, and from bottom to top, they are named B1, B2……Bn, wherein n is the tower climbing times; S2, tower reinforcement adopts the working mode of shear wall and surrounding frame beam collaborative force; S2.1, B1 tower reinforcement: one end of the tower tool beam is connected with the shear wall of the building, and the other end is placed on the surrounding frame beam; S2.2, B2 to Bn tower reinforcement: in the process of subsequent climbing, the shear wall and the structural beam jointly bear the tower load; S3, reinforcement design; S3.1, overall design of reinforcement mode: reinforcing the structure inside the shear wall side; Eight-shaped support is arranged on one side of the frame beam, one end of which is connected with the lower surface of the structural beam, and the other end is connected with the inner side of the cylinder; Connected with the two ends of the shear wall are two cylinders containing circular steel pipes, and the two ends of the eight-shaped support are connected with the structure in a hinged manner; S3.2, eight-shaped support and accessory component design: due to the different floor heights at different heights and the different length requirements of eight-shaped support, the eight-shaped support steel pipe adopts the mode of "reference modulus + adjustment modulus", wherein the reference modulus refers to the reference length of eight-shaped support, and the adjustment modulus is different adjustment length, according to the different length requirements of each layer, different adjustment modulus matching mode is selected.

2. The narrow core tube inner climbing tower crane high turnover reinforcement method according to claim 1, characterized in that: The height of the high-rise building in S1 includes the height of the basement, and the naming number of B1 to Bn is matched with the set floor height.

3. The narrow core tube inner climbing tower crane high turnover reinforcement method according to claim 1, characterized in that: The reference modulus and the adjustment modulus can be recycled, and only the end plate cannot be recycled.

4. The narrow core tube inner climbing tower crane high turnover reinforcement method according to claim 1, characterized in that: Before step S3, tower construction load analysis is carried out, and whether component reinforcement is needed is determined according to "unified standard for reliability design of building structure" GB50068-2018.

5. The narrow core tube inner climbing tower crane high turnover reinforcement method according to claim 1, characterized in that: In step S3.1, flange plate connecting piece is made at the connection node of the two ends of the eight-shaped support and the cylinder.

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