阅读说明：本技术 一种长悬臂平台的斜拉钢索安装方法 (Method for installing diagonal steel cable of long cantilever platform ) 是由 任少华 李善红 王选鹏 李伟跃 张强 王顺阳 张志坤 田长有 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种长悬臂平台的斜拉钢索安装方法,长悬臂平台包括烟囱回形平台,烟囱回形平台上与烟囱主体四个边角相对应的四个方向上均设置有主承重外挑悬梁,在主承重外挑悬梁上设置拉耳,在烟囱主体四个边角处设置拉索受力钢柱；将四根斜拉钢索的两端分别设置在相对应的拉索受力钢柱顶部和拉耳上,并在其两端设置千斤顶,利用千斤顶进行张拉,在烟囱主体顶部内壁四角设锰钢方管,在拉索受力钢柱上下两端分别增设拉杆和顶杆；对悬挑钢结构与斜拉钢索间连接部位进行加固焊接；对悬挑钢结构根部钢梁进行补强,焊接完毕后,对所有焊缝进行无损检测,复测各部件受力值,完成安装。本发明能够改善悬挑钢结构的受力方式,提高整个钢结构平台稳定性。(The invention discloses a method for installing a diagonal steel cable of a long cantilever platform, wherein the long cantilever platform comprises a chimney square-shaped platform, main bearing overhanging cantilever beams are arranged on the chimney square-shaped platform in four directions corresponding to four corners of a chimney main body, pull lugs are arranged on the main bearing overhanging cantilever beams, and stay cable stress steel columns are arranged at the four corners of the chimney main body; arranging two ends of four diagonal steel cables on the top and pull lugs of corresponding tension cable stress steel columns respectively, arranging jacks at the two ends of the four diagonal steel cables, tensioning by using the jacks, arranging manganese steel square pipes at four corners of the inner wall of the top of a chimney main body, and additionally arranging pull rods and ejector rods at the upper end and the lower end of each tension cable stress steel column respectively; reinforcing and welding the connection part between the cantilever steel structure and the diagonal steel cable; and reinforcing the steel beam at the root of the overhanging steel structure, carrying out nondestructive testing on all welding seams after welding, retesting stress values of all parts, and finishing installation. The invention can improve the stress mode of the cantilever steel structure and improve the stability of the whole steel structure platform.)

1. The method for installing the cable-stayed steel cable of the long cantilever platform comprises a chimney square platform arranged at the top of a chimney, wherein a main bearing overhanging cantilever beam is arranged on the chimney square platform in four directions corresponding to four corners of a chimney main body, and the method is characterized by comprising the following steps of:

s1, arranging pull lugs on the upper parts of the middle parts of the four main bearing overhanging cantilever beams, and arranging pull cable stressed steel columns on four corners of the chimney main body;

s2, carrying out primary test and recording on the sinking condition of the main bearing overhanging cantilever beam on the chimney square platform;

s3, after the initial measurement is finished, selecting eight temporary inhaul cables, pairwise pairing, respectively arranging one end of each pair of temporary inhaul cables at one side of the top of the corresponding inhaul cable stressed steel column, arranging the other end of each pair of temporary inhaul cables at one side of a pull lug corresponding to the inhaul cable stressed steel column, and fixing the two ends of each temporary inhaul cable by using an anchorage device self-locking device;

s4, after the two ends of the temporary inhaul cable are fixed, two hollow jacks are respectively arranged at the two ends of the temporary inhaul cable, the temporary inhaul cable is tensioned, and the tensioning force is not greater than the first-stage tensioning force;

s5, after the tensioning work is finished, retesting the main bearing outer cantilever beam on the chimney rectangular platform, comparing the retest with the previously measured numerical value, and finding out abnormality and adjusting the tensioning tension in time;

s6, after the temporary guys are installed and adjusted, the diagonal guys are installed, four diagonal guys are arranged, two ends of each of the four diagonal guys are respectively arranged on the tops of the corresponding stressed steel columns of the guys and the pull lugs, jacks are respectively arranged at two ends of each of the four diagonal guys, the tensile force is transmitted to the jacks through oil pumps, and then sleeves of the diagonal guys are adjusted until the force required to be applied is achieved;

s7, after prestress is applied to the diagonal steel cables through a jack, two diagonal steel cables in the left-right horizontal direction, namely the X direction, are communicated at the position below the upper roots of the diagonal steel cables, the east two corners and the west two corners are pulled respectively, the diagonal tension of the stay cables is converted into gravity, and the gravity acts on the upper part of the concrete structure on the chimney main body;

s8, manganese steel square pipes are additionally arranged at four corners of the inner wall of the top of the chimney main body, four steel plates are welded at each manganese steel square pipe, and each steel plate is implanted into a chimney concrete structure on the chimney main body through six phi 12 steel bars;

s9, respectively adding a pull rod and a push rod at the upper end and the lower end of the steel column for bearing the stay cable in the front-back vertical direction, namely the y direction;

s10, reinforcing and welding the connection part between the overhanging steel structure and the diagonal steel cable by using a reinforcing steel plate which has the same specification and material as the H-shaped steel rib plate in the overhanging steel structure on the chimney square platform;

s11, after the reinforcing welding is finished, performing nondestructive testing on all welding seams;

s12, reinforcing the steel beam at the root of the overhanging steel structure by adopting a steel plate which has the same specification and material as the wing plate of the H-shaped steel beam in the overhanging steel structure on the chimney rectangular platform, reinforcing the H-shaped steel at the root of the bearing beam into a more stable box-shaped body by using the steel plate, welding in a skip welding mode during reinforcing, carrying out nondestructive detection on all welding seams after welding is finished, wherein the height of the welding seam is not less than the thickness of the thinnest part;

and S13, after reinforcement, retesting stress values of all parts, and finishing installation.

2. The method for installing the diagonal steel cable of the long cantilever platform according to claim 1, wherein the method comprises the following steps: in S12, before reinforcing the steel beam, a set of door frame is manufactured on the steel beam, the door frame and the steel beam are welded and reinforced, and a 3-ton chain block is hung on the door frame; after the construction of the cable-stayed steel cable is completed, the steel plate needs to be processed in a zero meter according to the drawing size, a winch is utilized to convey a reinforcing steel plate to the chimney circular platform, the chain block is adopted to hoist the steel plate to the position above the steel beam needing to be reinforced, and the steel plate is welded and reinforced after being attached to the steel beam.

3. The method for installing the diagonal steel cable of the long cantilever platform according to claim 1, wherein the method comprises the following steps: the suspension cable is characterized in that the suspension cable is determined to be a parallel cable with the breaking load of 1221KN and the model of 7 multiplied by 19 (the diameter is multiplied by the number), the stress of the suspension cable is 450KN, the suspension cable is processed by steel wires, the outer part of the suspension cable is protected by epoxy resin, the two ends of the suspension cable are provided with adjustable shock absorbers, the safety of the whole steel structure truss is ensured, and the temporary cable is a steel strand with the diameter of phi 15.2mm and the strength of 1860 MPa.

4. The method for installing the diagonal steel cable of the long cantilever platform according to claim 1, wherein the method comprises the following steps: the stress of the temporary stay cable and the cable-stayed steel cable is different due to different sinkage of four corners of the platform, and when the tension moment is adjusted, the tension moment of the cable-stayed steel cable is 0 to +5 percent of the design value, namely: when the primary design value is 250KN, the primary tension moment value is 250 KN-262.5 KN; when the secondary design value is 450KN, the secondary tension moment value is 450 KN-472.5 KN.

5. The method for installing the diagonal steel cable of the long cantilever platform according to claim 4, wherein the method comprises the following steps: the temporary stay cable and the cable-stayed steel cable are simultaneously tensioned, after one side of the temporary stay cable and one side of the cable-stayed steel cable are tensioned, the opposite side of the temporary stay cable and the cable-stayed steel cable are tensioned, all tension in the whole tensioning engineering is resolved into gravity, the stress of the stay cable is monitored in the tensioning process, the steel platform data are retested and compared with the original data after tensioning is finished, and the tensioning tension of the cable-stayed steel cable is controlled within 5 percent, namely 450 multiplied by 0.05=22.5 KN.

6. The method for installing the diagonal steel cable of the long cantilever platform according to claim 1, wherein the method comprises the following steps: the pull lug is connected with the cable-stayed steel cable through a pin shaft.

Technical Field

The invention relates to a method for installing a diagonal steel cable, in particular to a method for installing a diagonal steel cable of a long cantilever platform.

Background

The industrial design is fully considered during the design of a certain waste incineration power station, a clip-shaped platform for visitors to overlook the whole plant and surrounding wind and light is designed at the top of a chimney, the clip-shaped platform is designed on 70.50m, 73.51m and 79.57m layers of the chimney, and the design of an upper layer cantilever steel structure, a middle layer cantilever steel structure and a lower layer cantilever steel structure is adopted, wherein the cantilever distance of a main bearing beam of a roof is 17.44 meters, the main bearing beam is influenced by other buildings around the chimney, the operation space is narrow, and a crane used for hoisting a steel beam can only be used for standing in an area other than dozens of meters for operation, so the hoisting difficulty is very high; in order to ensure the installation quality of the platform, before the cantilever steel structure is installed, construction units organize related technicians to demonstrate the hoisting process of the platform steel structure, the stress of the root part of a main bearing cantilever beam with the longest cantilever distance is found to be problematic during the process, the stress is confirmed together with a design institute, in order to improve the stress of the bearing beam, four oblique steel cables are added at the cantilever bearing beams at four corners of the platform roof, the horizontal oblique beam at the root of the steel structure at each layer of the platform is reinforced, but because the oblique steel cable structure is subsequently added on the finished building, the installation of the oblique steel cables and the reinforcement of the horizontal oblique beam at the root of the steel structure at each layer of the platform need to be installed according to actual conditions, otherwise, the stress problem cannot be solved, and the construction period is prolonged.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the problems in the prior art and provides a method for installing a diagonal steel cable of a long cantilever platform, which can improve the stress mode of a cantilever steel structure, maintain the integral aesthetic property of a chimney square-shaped platform and improve the stability of the whole steel structure platform.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a method for installing a cable-stayed steel cable of a long cantilever platform comprises the steps that the chimney square platform is arranged at the top of a chimney, a main bearing overhanging cantilever beam is arranged on the chimney square platform in four directions corresponding to four corners of a chimney main body, and the method comprises the following steps:

s1, arranging pull lugs on the upper parts of the middle parts of the four main bearing overhanging cantilever beams, and arranging pull cable stressed steel columns on four corners of the chimney main body;

s2, carrying out primary test and recording on the sinking condition of the main bearing overhanging cantilever beam on the chimney square platform;

s3, after the initial measurement is finished, selecting eight temporary inhaul cables, pairwise pairing, respectively arranging one end of each pair of temporary inhaul cables at one side of the top of the corresponding inhaul cable stressed steel column, arranging the other end of each pair of temporary inhaul cables at one side of a pull lug corresponding to the inhaul cable stressed steel column, and fixing the two ends of each temporary inhaul cable by using an anchorage device self-locking device;

s4, after the two ends of the temporary inhaul cable are fixed, two hollow jacks are respectively arranged at the two ends of the temporary inhaul cable, the temporary inhaul cable is tensioned, and the tensioning force is not greater than the first-stage tensioning force;

s5, after the tensioning work is finished, retesting the main bearing outer cantilever beam on the chimney rectangular platform, comparing the retest with the previously measured numerical value, and finding out abnormality and adjusting the tensioning tension in time;

s6, after the temporary guys are installed and adjusted, the diagonal guys are installed, four diagonal guys are arranged, two ends of each of the four diagonal guys are respectively arranged on the tops of the corresponding stressed steel columns of the guys and the pull lugs, jacks are respectively arranged at two ends of each of the four diagonal guys, the tensile force is transmitted to the jacks through oil pumps, and then sleeves of the diagonal guys are adjusted until the force required to be applied is achieved;

s7, after prestress is applied to the diagonal steel cables through a jack, two diagonal steel cables in the left-right horizontal direction, namely the X direction, are communicated at the position below the upper roots of the diagonal steel cables, the east two corners and the west two corners are pulled respectively, the diagonal tension of the stay cables is converted into gravity, and the gravity acts on the upper part of the concrete structure on the chimney main body;

s8, manganese steel square pipes are additionally arranged at four corners of the inner wall of the top of the chimney main body, four steel plates are welded at each manganese steel square pipe, and each steel plate is implanted into a chimney concrete structure on the chimney main body through six phi 12 steel bars;

s9, respectively adding a pull rod and a push rod at the upper end and the lower end of the steel column for bearing the stay cable in the front-back vertical direction, namely the y direction;

s10, reinforcing and welding the connection part between the overhanging steel structure and the diagonal steel cable by using a reinforcing steel plate which has the same specification and material as the H-shaped steel rib plate in the overhanging steel structure on the chimney square platform;

s11, after the reinforcing welding is finished, performing nondestructive testing on all welding seams;

s12, reinforcing the steel beam at the root of the overhanging steel structure by adopting a steel plate which has the same specification and material as the wing plate of the H-shaped steel beam in the overhanging steel structure on the chimney rectangular platform, reinforcing the H-shaped steel at the root of the bearing beam into a more stable box-shaped body by using the steel plate, welding in a skip welding mode during reinforcing, carrying out nondestructive detection on all welding seams after welding is finished, wherein the height of the welding seam is not less than the thickness of the thinnest part;

and S13, after reinforcement, retesting stress values of all parts, and finishing installation.

In S12, before reinforcing the steel beam, a set of door frame is manufactured on the steel beam, the door frame and the steel beam are welded and reinforced, and a 3-ton chain block is hung on the door frame; after the construction of the cable-stayed steel cable is completed, the steel plate needs to be processed in a zero meter according to the drawing size, a winch is utilized to convey a reinforcing steel plate to the chimney circular platform, the chain block is adopted to hoist the steel plate to the position above the steel beam needing to be reinforced, and the steel plate is welded and reinforced after being attached to the steel beam.

The suspension cable is characterized in that the suspension cable is determined to be a parallel cable with the breaking load of 1221KN and the model of 7 multiplied by 19 (the diameter is multiplied by the number), the stress of the suspension cable is 450KN, the suspension cable is processed by steel wires, the outer part of the suspension cable is protected by epoxy resin, the two ends of the suspension cable are provided with adjustable shock absorbers, the safety of the whole steel structure truss is ensured, and the temporary cable is a steel strand with the diameter of phi 15.2mm and the strength of 1860 MPa.

The stress of the temporary stay cable and the cable-stayed steel cable is different due to different sinkage of four corners of the platform, and when the tension moment is adjusted, the tension moment of the cable-stayed steel cable is 0 to +5 percent of the design value, namely: when the primary design value is 250KN, the primary tension moment value is 250 KN-262.5 KN; when the secondary design value is 450KN, the secondary tension moment value is 450 KN-472.5 KN.

The temporary stay cable and the cable-stayed steel cable are simultaneously tensioned, after one side of the temporary stay cable and one side of the cable-stayed steel cable are tensioned, the opposite side of the temporary stay cable and the cable-stayed steel cable are tensioned, all tension in the whole tensioning engineering is resolved into gravity, the stress of the stay cable is monitored in the tensioning process, the steel platform data are retested and compared with the original data after tensioning is finished, and the tensioning tension of the cable-stayed steel cable is controlled within 5 percent, namely 450 multiplied by 0.05=22.5 KN.

The pull lug is connected with the cable-stayed steel cable through a pin shaft.

A cable-stayed steel cable device of a long cantilever platform comprises a chimney square platform arranged on the circumference of the upper part of a chimney main body, wherein a main bearing overhanging cantilever beam is arranged on the chimney square platform in four directions corresponding to four corners of the chimney main body, pull lugs are arranged on the upper parts of the middle parts of the four main bearing overhanging cantilever beams, and pull cable stress steel columns are arranged at the four corners of the inner wall of the chimney main body; and an inclined steel cable is respectively arranged between each pull lug and the corresponding stay cable stress steel column, one end of each inclined steel cable is connected with the pull lug through a pin shaft, the other end of each inclined steel cable penetrates through the side wall of the chimney body and is connected with the upper part of the corresponding stay cable stress steel column, and a reflective belt is arranged on each inclined steel cable.

The lower extreme of draw the cable wire to one side with the ear of pulling junction is provided with two at least reinforcement steel sheets, be provided with the floor between the reinforcement steel sheet.

The stay cable stress steel column comprises square tubes and steel plates, each steel plate is implanted into the concrete structure on the inner wall of the chimney main body through six steel bars with the diameter of phi 12, and the square tubes are connected with the steel plates in a welded mode.

The novel steel cable square pipe is characterized in that concrete is arranged in the square pipe, embedded parts are arranged in the concrete, extend out of the outer wall of the square pipe and are respectively connected with the cable-stayed steel cable, the pull rod and the pressure rod, each embedded part comprises a first embedded part, a second embedded part and a third embedded part, the first embedded part is arranged on the upper portion of the square pipe, the second embedded part is arranged below the first embedded part, and the third embedded part is arranged on the lower portion of the square pipe.

Four two liang settings are in to one side cable-stay cable wire is in on the left surface of chimney main part and the right flank, wherein two to one side cable-stay cable wire runs through respectively behind the front and back both ends of the left side wall of chimney main part, respectively with two that correspond square pipe is last first built-in fitting is connected, two in addition to one side cable-stay cable wire runs through respectively behind the right side wall of chimney main part, respectively with two in addition that correspond square pipe is last first built-in fitting is connected.

The number of the pull rods and the number of the pressure rods are four, two of the pull rods are respectively arranged on two square pipes close to the front side wall and located at one end, far away from the left side wall or the right side wall, of the two square pipes, and the other two of the pull rods are respectively arranged on two square pipes close to the rear side wall and located at one end, far away from the left side wall or the right side wall, of the two square pipes; all the pull rods are respectively connected with the second embedded parts corresponding to the pull rods, and all the press rods are respectively connected with the third embedded parts corresponding to the press rods.

The cable-stayed steel cable is characterized in that the cable-stayed steel cable is a parallel cable, a steel wire is arranged inside the cable-stayed steel cable, epoxy resin is arranged outside the cable-stayed steel cable and used for protecting the cable-stayed steel cable, and adjustable shock absorbers are arranged at two ends of the cable-stayed steel cable.

The invention has the following positive beneficial effects:

1. on the basis of keeping the existing design, four diagonal steel cables are added on the main bearing beam cantilevers at the four corners of the chimney square-shaped platform roof, and the root of a steel structure on the chimney square-shaped platform is reinforced, so that the stress mode of the cantilever steel structure is improved, the integral attractiveness is maintained, and the stability of the whole steel structure platform is improved.

2. The steel stay cable is applied to the steel structure platform of the waste incineration power station, the application range of the steel stay cable is widened, the self weight of the high-altitude overhanging steel structure is reduced, the idea is developed for the design of the same type of platform, and the installation period is shortened.

3. The invention uses small machines such as a winch and a chain block, avoids the cost of using large machines in the previous platform reinforcing, dismantling, correcting and installing period and period, and saves the construction cost.

Drawings

FIG. 1 is a flow chart of a method for installing a cable-stayed cable of a long cantilever platform according to the present invention;

FIG. 2 is a schematic structural view of the present invention between the stay-cable steel cable and the pull tab and the chimney body;

FIG. 3 is a schematic structural diagram of the chimney body and the bracing cable stressed steel column in FIG. 2;

figure 4 is a top view of the chimney body of the present invention.

Detailed Description

The invention will be further explained and explained with reference to the accompanying drawings, fig. 1, fig. 2, fig. 3, fig. 4 and the specific embodiments:

in the figure, 1-a chimney square platform, 2-a chimney main body, 3-a smoke exhaust steel cylinder, 4-a pull lug, 5-a pull cable stress steel column, 6-a diagonal steel cable, 7-a reinforced steel plate, 8-a pull rod, 9-a pressure rod, 10-a first embedded part, 11-a second embedded part and 12-a third embedded part.

Example (b): in the embodiment, the external dimension of the chimney main body 2 is 13.83m × 20.35m, the internal cylinder is 6 smoke exhaust steel cylinders 3, the building base area is 281.44 square meters, the top elevation of the cylinder wall is 88.5m, the chimney clip platform 1 is arranged on the chimney 70.50m, 73.51m and 79.57m layers, the design of an upper layer cantilever steel structure, a middle layer cantilever steel structure and a lower layer cantilever steel structure is adopted, the distance between a main bearing cantilever beam on the upper layer cantilever steel structure of the chimney clip platform 1 and a main bearing cantilever beam on the roof is 17.44 m, steel components on the chimney clip platform 1 are all made of Q235-B steel, the factory prefabrication is realized, a small number of manual arc welding is adopted on the site, the cantilever platform bearing steel beams are connected in a friction mode through 10.9-level high-strength bolts, and the mounting sequence of the cantilever steel structures is from bottom to top: firstly, 70.50m layers are installed, then 73.51m layers are installed, and finally 79.57m layers are installed; the chimney square platform 1 is arranged around the chimney main body 2.

In the process of installing the inclined pull steel cable 6, the pull lugs 4 are arranged on the upper portions of the middle portions of the four main bearing overhanging beams on the upper overhanging steel structure on the chimney square platform 1, the pull cable stress steel columns 5 are arranged at the four corners of the chimney body 2, and the joints of the inclined pull steel cable 6 and the pull cable stress steel columns 5 are arranged at 87m positions on the chimney body 2.

And then carrying out primary test and recording on the sinking condition of the main bearing overhanging cantilever beam on the chimney rectangular platform 1.

After the preliminary survey was accomplished, select eight interim cables, two liang are in pairs, will set up respectively in one side at corresponding cable atress steel column 5 top to the one end of every pair of interim cable, and the other end setting is in the one side of pulling the ear 4 corresponding with cable atress steel column 5, and interim cable both ends utilize anchorage device self-locking device to fix.

After the two ends of the temporary inhaul cable are fixed, the two hollow jacks are respectively arranged at the two ends of the temporary inhaul cable, the temporary inhaul cable is tensioned, and the tensioning force is not greater than the first-stage tensioning tension force (less than 250 KN) provided by a design institute.

After the tensioning work is finished, a specially-assigned person retests the main bearing overhanging cantilever beam on the chimney rectangular platform 1, compares the retest with the previously measured numerical value, and timely adjusts the tensioning tension when finding abnormality.

After all the temporary guys are installed and adjusted, the diagonal guys 6 can be installed, four diagonal guys 6 are arranged, two ends of each of the four diagonal guys 6 are respectively arranged on the top of the corresponding guy stressed steel column 5 and the pull lug 4, jacks are respectively arranged at two ends of each of the four diagonal guys 6, and prestress is applied through the jacks; the tensile force is transmitted to the jacks at the two ends of the cable-stayed steel cable 6 through the oil pump, and then the sleeve of the cable-stayed steel cable 6 is adjusted to achieve the required force.

The pull lug 4 is connected with the cable-stayed steel cable 6 through a pin shaft, the pull lug 4 and the pin shaft can be made of Q235 profile steel, and the pull lug 4 and the pin shaft are subjected to strength check before installation.

At root below position department on the cable-stay cable 6, link up two cable-stay cables 6 on the horizontal direction about, the X direction, to drawing east both corners and west both corners respectively, convert the cable diagonal tension into gravity, act on concrete structure upper portion, make the structure full play concrete compressive property, reduce the destruction to the structure of concrete.

In order to ensure the structure of the chimney main body 2 and meet the pulling force value of 750kn at each angle of the stay cable, 4.5m of a 300 x 12 long manganese steel square pipe is added at four corners of the inner wall of the top of the chimney main body 2, four 1000 x 600 x 20 steel plates are welded at each manganese steel square pipe, and each steel plate is implanted into a chimney concrete structure on the chimney main body 2 by adopting six phi 12 steel planting bars, so that the structural destructive power of the chimney main body 2 is reduced in the stress process of the stay cable, and the stress in the x direction is through the stay cable, so that the reactive force is generated to be mutually offset.

In order to ensure the concrete structure, pull rods 8 are additionally arranged at the upper and lower ends of a stay cable stressed steel column 5 in the y direction, and ejector rods are additionally arranged at the lower part of the stay cable stressed steel column, so that the outward destructive force of the stay cable 6 to the y direction of the structure of the chimney main body 2 in the stress process is decomposed into pressure to the concrete structure of the chimney through the pull rods 8 and the press rods 9, and the stability of the structure is ensured.

Adopt and encorbelment the same specification of H shaped steel floor in the steel construction on the chimney return platform 1, with the Q235 steel sheet of material to encorbelment steel construction and cable between the connection position consolidate, specifically consolidate the welding to steel construction atress position around the cross node to ensure the intensity of atress position steel construction, improve the atress situation of encorbelment steel construction and cable between the connection position, node consolidation welding is finished the back, carries out nondestructive test to all welding seams.

Adopt and encorbelment steel sheet with H shaped steel roof beam pterygoid lamina with specification in the steel construction on the chimney return platform 1, with the material to 79.57 meters steel construction root girder steel of encorbelmenting reinforce, consolidate into the box type body that stabilizes more with the H shaped steel of spandrel girder root with the steel sheet, during the reinforcement, adopt the mode of skip welding to weld, the welding seam height is not less than the thickness of thinnest spare.

In the process of laying the inhaul cable, a specially-assigned person is required to conduct and coordinate uniformly.

Before the steel beam is reinforced, a set of door frame is manufactured on the steel beam, the door frame and the steel beam are welded and reinforced, and a 3-ton chain block is hung on the door frame; the cable needs to be constructed and is accomplished, and the steel sheet needs to be at zero meters processing completion according to the drawing size, utilizes the hoist engine to transport the reinforcing steel sheet to 79 meters, adopts chain block hoist and mount steel sheet to need to consolidate the girder steel top, waits to weld, strengthen after steel sheet and the girder steel laminating.

The steel plate for reinforcing the steel structure is made of Q235-B, and a rib plate is arranged in the middle of the steel plate for improving the strength of the box body.

The particularity and the aesthetic property of the service environment are considered in the embodiment, the steel cable is selected according to the type to ensure the safety of the whole steel structure truss, the structure is safe and reliable, the manufacturing cost is economical and reasonable, the used equipment and materials are safe, stable and firm in the service cycle, and when the materials are selected, the common use, the turnover utilization and the convenient maintenance are realized.

The parallel stay cable with the breaking load of 1221KN and the model of 7 multiplied by 19 (the diameter is multiplied by the number) is determined to be selected for the cable-stayed cable 6, the stress of the cable-stayed cable 6 is 450KN, the cable-stayed cable 6 is processed by steel wires, the outer part of the cable-stayed cable 6 is protected by epoxy resin, and the two ends of the cable-stayed cable adopt adjustable damping devices to ensure the safety of the whole steel structure truss.

The temporary stay cable is a steel strand with the diameter phi of 15.2mm and the strength of 1860 MPa, the stress of the temporary stay cable and the cable-stayed steel cable 6 is different due to different sinking amounts of four corners of the platform, so the tension moment of the stay cable is particularly important to be adjusted, and the tension moment of the cable-stayed steel cable 6 is 0 to +5 percent of the design value, namely: when the primary design value is 250KN, the primary tension moment value is 250 KN-262.5 KN; when the secondary design value is 450KN, the secondary tension moment value is 450 KN-472.5 KN.

Monitoring the pressure value of the jack and the change of the steel beam at any time during the tensioning of the stay cable, arranging a specially-assigned person to measure, record and compare every day after tensioning is finished, and analyzing the reason in time and making reliable adjustment measures when the change occurs.

In order to ensure that the reinforcing parts are safely hoisted in place, hoisting points of the reinforcing parts are hoisted by welding a plurality of lifting lugs; in order to avoid the additional external force generated by thermal deformation and thermal stress generated during welding on the existing steel beam, skip welding, back welding and symmetrical welding are alternately carried out in the welding process of all components, so that the additional external force is reduced to the minimum, a specially-assigned person is required to carry out uninterrupted measurement on the whole steel structure platform during welding, and all operations are required to be stopped immediately when abnormal conditions occur.

Before the temporary stay cable and the oblique-pulling steel cable 6 are used, prestress release needs to be carried out on the temporary stay cable and the oblique-pulling steel cable 6, a 1t winch is arranged on the chimney return-shaped platform 1, after the temporary stay cable or the oblique-pulling steel cable 6 is hung to the chimney return-shaped platform 1, defect inspection is carried out on an exposed part and a protective layer thereof after an external package is removed, after the external package is qualified, a steel wire rope on the winch is connected with the temporary stay cable or the oblique-pulling steel cable 6, the winch is started, firstly, the temporary stay cable or the oblique-pulling steel cable 6 is slowly stretched, and the temporary stay cable or the oblique-pulling steel cable 6 is placed on a cable-unfolding trolley so as to ensure that the temporary stay cable or the oblique-pulling steel cable 6 is not in contact friction on the ground.

For uniform tensioning, the two ends of the temporary stay cable and the inclined pull steel cable 6 are simultaneously tensioned, after one side is tensioned, the opposite side is tensioned, all the tension in the whole tensioning project is resolved into gravity, the stress of the stay cable is monitored in the tensioning process, the steel platform data is retested and compared with the original data after tensioning is finished, and the tensioning tension of the inclined pull steel cable 6 is controlled within 5%, namely 450 × 0.05=22.5 KN.

The pull lugs 4 are connected with the cable-stayed steel cables 6 through pin shafts, and after reinforcement, stress values of all parts are retested to complete installation.

In the above, the integral structure of the stayed cable 6 comprises pull lugs 4 arranged at the upper parts of the middle parts of the four main bearing cantilever beams, and pull cable stress steel columns 5 arranged at the four corners of the inner wall of the chimney main body 2; and an oblique pull steel cable 6 is respectively arranged between each pull lug 4 and the corresponding pull cable stress steel column 5, one end of the oblique pull steel cable 6 is connected with the pull lug 4 through a pin shaft, the other end of the oblique pull steel cable 6 penetrates through the side wall of the chimney main body 2 and then is connected with the upper part of the corresponding pull cable stress steel column 5, and a reflective belt is arranged on the oblique pull steel cable 6.

The lower end of the joint of the diagonal steel cable 6 and the pull lug 4 is provided with at least two reinforcing steel plates 7, and rib plates are arranged between the reinforcing steel plates 7.

The inhaul cable stress steel column 5 comprises square pipes and steel plates, each steel plate is implanted into the concrete structure on the inner wall of the chimney main body 2 through six steel planting bars with the diameter of phi 12, and the square pipes are connected with the steel plates in a welded mode.

The square pipe is internally provided with concrete, the concrete is internally provided with embedded parts, the embedded parts extend out of the outer wall of the square pipe and are respectively connected with the diagonal steel cable 6, the pull rod 8 and the press rod 9, the embedded parts comprise first embedded parts 10, second embedded parts 11 and third embedded parts 12, the first embedded parts 10 are arranged on the upper portion of the square pipe, the second embedded parts 11 are arranged below the first embedded parts 10, and the third embedded parts 12 are arranged on the lower portion of the square pipe.

The four diagonal steel cables 6 are arranged on the left side surface and the right side surface of the chimney body 2 in a pairwise manner, wherein the two diagonal steel cables 6 are respectively connected with the first embedded parts 10 on the two corresponding square pipes after penetrating through the front end and the rear end of the left side wall of the chimney body 2, and the other two diagonal steel cables 6 are respectively connected with the first embedded parts 10 on the other two corresponding square pipes after penetrating through the right side wall of the chimney body 2.

Four pull rods 8 and four pressure rods 9 are arranged, wherein two pull rods 8 are respectively arranged on two square tubes close to the front side wall and positioned at one end of the two square tubes far away from the left side wall or the right side wall, and the other two pull rods 8 are respectively arranged on two square tubes close to the rear side wall and positioned at one end of the two square tubes far away from the left side wall or the right side wall; all the pull rods 8 are respectively connected with the corresponding second embedded parts 11, and all the press rods 9 are respectively connected with the corresponding third embedded parts 12.

The cable-stayed cable 6 adopts a parallel cable, the inside of the cable-stayed cable 6 is provided with a steel wire, the outside is provided with epoxy resin, the cable-stayed cable 6 is protected, and the two ends of the cable-stayed cable 6 are provided with adjustable shock absorbers

The invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the invention, and such equivalent modifications or substitutions are included in the scope defined by the claims of the present application.