CN117449209A

CN117449209A - Bridge steel structure installation construction folding method

Info

Publication number: CN117449209A
Application number: CN202311641547.5A
Authority: CN
Inventors: 谭小磊; 贺刚强; 石刘; 黄超; 艾飞; 罗川; 尤爰智; 闵永清
Original assignee: CCCC First Highway Engineering Co Ltd; Fourth Engineering Co Ltd of CCCC First Highway Engineering Co Ltd
Current assignee: CCCC First Highway Engineering Co Ltd; Fourth Engineering Co Ltd of CCCC First Highway Engineering Co Ltd
Priority date: 2023-12-01
Filing date: 2023-12-01
Publication date: 2024-01-26

Abstract

The invention provides a bridge steel structure installation construction closure method, which belongs to the field of steel structure installation construction closure, and comprises the following steps: the method comprises the steps of installing and constructing a steel box girder, constructing a stay cable and constructing a closure section, wherein the installing and constructing the steel box girder comprises hoisting the girder section, performing fine matching and temporary connection, and the constructing of the stay cable comprises preparing work on a construction site, installing a stay cable on a bridge, installing a stay cable tower end, installing a stay cable, installing a girder end, tensioning the stay cable, adjusting the cable and damping the stay cable; the closure section construction comprises closure opening posture adjustment, closure opening monitoring, closure section matching and cutting, closure section hoisting, beam Duan Jingdu matching, matching end code fixing, matching and cutting end fixing closure opening and system conversion. According to the invention, the temperature is detected in real time in the folding process, and then folding and installation are carried out according to the temperature data, so that the installation accuracy is higher, meanwhile, two vibration reduction devices are arranged on the stay cable, and the main beam vibrates along with the stay cable, so that the situations of fatigue damage of the root of the stay cable, inaccurate measurement construction on the main beam and the like are caused.

Description

Bridge steel structure installation construction folding method

Technical Field

The invention relates to the field of steel structure installation construction closure, in particular to a bridge steel structure installation construction closure method.

Background

The steel box girder is also called a steel plate box girder, and is a common structural form of a large-span bridge. Is commonly used on bridges with larger spans, and is called a steel box girder because of the shape of a box. The steel box girder is also called a steel plate box girder, and is a common structural form of a large-span bridge. Is commonly used on bridges with larger spans, and is called a steel box girder because of the shape of a box. The stay cable is an important modern large-span bridge form with a structure, and particularly when an extra large bridge with a large span is erected at places such as canyons, gulfs, large rivers and the like which are difficult to build bridge piers, a suspension bridge and a cable-stayed bridge are always selected. The last step of folding is left after the stay cable is constructed, the existing construction method can cause errors in folding, the construction efficiency is low, meanwhile, the folding has the problem of insufficient precision and the like due to temperature and other changes, and therefore, a high-precision and high-efficiency bridge steel structure installation, construction and folding method needs to be designed.

Disclosure of Invention

The invention aims to provide a bridge steel structure installation construction folding method, which solves the existing technical problems.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

A bridge steel structure installation construction closure method comprises the following steps:

step 1: the method comprises the steps of installing and constructing the steel box girder, wherein the method comprises the steps of hoisting girder sections, fine matching and temporary connection, hoisting girder Duan Qi by adopting a two-point hoisting method, accurately calibrating the position of the erected girder sections by using a theodolite before hoisting each girder section, carrying out a lifting tool positioning test, hoisting after positioning adjustment so as to prevent the girder sections from shifting in position to generate transverse swinging, carrying out point-to-point hoisting on 39 transitional girder sections and standard girder sections of the steel box girder by adopting a bridge deck crane, wherein the hoisting of each standard girder section comprises the steps of girder Duan Disheng, girder Duan Chu matching, girder Duan Jing matching and girder Duan Gong connection and load transfer from the bridge deck crane to a diagonal cable;

step 2: the stay cable construction comprises the steps of preparing work on a construction site, installing a stay cable upper bridge, installing a stay cable tower end, installing a stay cable expanding rope, installing a beam end, tensioning the stay cable, adjusting the rope and damping the stay cable;

step 3: the closure section construction comprises closure opening posture adjustment, closure opening monitoring, closure section matching and cutting, closure section hoisting, beam Duan Jingdu matching, matching end code fixing, matching and cutting end fixing closure opening and system conversion.

Further, the specific process of lifting the beam section in the step 1 is as follows:

1) Selecting favorable weather conditions for beam section hoisting operation, wherein the gust wind speed at the bridge deck elevation is not more than 20m/s, and applying to maritime departments in advance to enable hoisting construction;

2) The water conveying beam Duan Bochuan is stopped at a monitoring area right below the bridge deck crane, the beam Duan Pingfang is in place, and the positioning error of the conveying beam Liang Chuan is not more than +/-2.5 m, so that the beam section is prevented from swinging during hoisting;

3) Starting a continuous jack to lower 2 sets of bridge deck shoulder pole beam systems to the top surface of the lifting beam section;

4) Lifting a preset position of a lifting appliance by using an amplitude variation mechanism on a bridge deck crane, and reserving a lifting space of 200mm between the installed beam Duan Bianyuan and a beam Duan Bianyuan to be lifted;

5) Connecting the shoulder pole beam with the bridge deck lifting lug by using a lifting belt, and checking the crane and the lifting lug to ensure that each lifting point is uniformly stressed;

6) Starting a double-station lifting continuous jack to enable the jacks to lift simultaneously, tensioning a steel wire rope slowly until the beam leaves Liang Chuan, stopping lifting when the beam needs to be leveled, starting a shoulder pole beam lifting appliance leveling system to level, carrying out static load and dynamic load test before formally lifting each beam section, and debugging a crane braking system;

7) In long-stroke lifting, the beam blocks can incline due to the speed difference of the jacks and stop temporarily, the linkage jacks can automatically adjust the restoration level, and when the beam blocks rise to the bridge deck, any jack is started to adjust the transverse bridge of the beam blocks to be horizontal, so that the lifting beam and the installed beam section are basically horizontal.

Further, the specific process of the initial matching of the beam section in the step 1 is as follows:

1) The beam Duan Zhi is hoisted by an amplitude variation mechanism on the crane to be Duan Bianyuan mm away from the installed beam;

2) Adjusting a bridge deck leveling cylinder on the longitudinal shoulder pole beam to adjust a bridge deck longitudinal slope to be matched with the installed beam Duan Da;

3) Continuously adjusting to enable the top surfaces of the beams to be basically flush, and transversely adjusting and aligning axes of the two steel box beams by using a chain block;

4) And adjusting the amplitude variation mechanism to be within 10mm from the installed beam Duan Bianyuan, repeating the longitudinal and transverse adjustment until the beam section is contacted with the installed beam section, the axis is connected with the installed beam section in sequence, then inserting and driving a temporary matching piece punch pin, installing a matching piece bolt, screwing, and locking a lifting jack to finish primary matching.

Further, the specific process of beam section fine matching in the step 1 is as follows:

1) The fine matching is carried out when the temperature difference of the top plate and the bottom plate is less than 2 ℃;

2) Carrying out local linear measurement of the main beam at the front end of the cantilever, comparing control instructions, and determining the longitudinal slope adjustment quantity of the hoisting main beam;

3) Loosening Liang Duanjian temporary matching piece bolts and preparing for longitudinal slope adjustment;

4) The bridge deck crane is moved to lift the jack, and the relative height difference of the beam section control points is adjusted to meet the monitoring requirement;

5) The mileage adjustment of the steel beam is carried out by adopting a high-strength bolt matched with a temporary matching piece, and the axial deviation chain block is transversely adjusted in a pulling way;

6) Re-measuring the partial line shape and the axis of the front end of the cantilever of the beam section, screwing a bolt of a matching piece after meeting the monitoring requirement, and locking a jack to finish accurate matching;

7) The local residual height difference of the web plate and the top plate is adjusted by a bridge deck jack, and is leveled by a stacking plate.

5. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the concrete process of the bridge section construction site connection and load transfer from the bridge deck crane to the stay cable in the step 1 is as follows:

1) The connection between the hoisting beam section and the installed beam Duan Jiefeng is completed, the web plate part is firstly connected when the beam section is connected, then the bottom plate is welded, then the bolting of the U rib of the top plate and the welding of the top plate are carried out, and the connection sequence is carried out from the middle of the box beam to the two sides;

2) Installing and tensioning corresponding stay cables for the first time;

3) Starting a continuous jack, lowering the shoulder pole beam by 200mm, and then removing a steel wire rope hanging rope for connecting the shoulder pole beam and the beam section;

4) Lifting the shoulder pole beam by using a lifting jack to adjust the shoulder pole beam away from the beam section;

5) A forward crane;

6) And tensioning the corresponding stay cable for the second time, so as to finish hoisting of one standard beam section and prepare for hoisting of the next standard beam section.

Further, the concrete process of preparing the job site in the step 2 is as follows:

(1) The preparation work in the tower box comprises the following steps:

1) The whole operation platform is erected in two layers, the anchoring position of the stay cable is erected as a lower layer and is mainly used for assembling and disassembling a tension rod jack, and the anchoring position of the next cable is erected as an upper layer and is used for placing an oil pump;

2) The method comprises the steps of preparing traction work of a lifting head, welding a fixed point serving as a fixed point of a guide pulley on a tower limb wall in the extending direction of a central axis of a cable guide pipe, dragging a traction rope of the lifting head, after the tower limb is capped, arranging two winches at the top of the tower to serve as lifting equipment in the tower and dragging equipment of the lifting head when a cable is hung, connecting the lifting head and a steel wire rope of the winch at the top of the tower by using a clamping ring in a tower box before the cable is hung, penetrating through an anchor nut at the tower end of the cable-stayed cable, and paying out the tower limb to a main beam;

(2) The preparation work outside the tower comprises the arrangement of a tower top hanging bracket and the arrangement of a beam end winch;

(3) Removing cement mortar, welding slag and burrs at pipe orifices in the embedded cable guide pipe, removing mortar, welding slag and the like on the anchor backing plate, ensuring that the anchor plate is closely adhered to the anchor backing plate, checking the size of a notch of an anchor head to determine the installation position of a jack, and discharging a cross center line of a pore opening on the anchor backing plate so as to center;

The concrete process of the stay cable upper bridge is as follows:

the stay cables are transported in a land transportation mode, transported to a construction site through a construction passageway, and hoisted by using a tower crane in a range allowed by the lifting capacity of the tower crane, wherein the stay cables of the tower crane on the bridge cannot be hoisted by adopting proper hoisting equipment according to the weight and hoisting amplitude;

in the installation of cable-stayed tower end, adopting tower crane or tower top hanging frame to install tower end of cable-stayed cable according to project site condition, when the installation of cable-stayed tower end can not adopt tower crane to install, it needs to adopt tower top hanging frame as cable-stayed tower end installation lifting equipment, when the design of tower top hanging frame needs to confirm the length of encorbelmenting according to body appearance and hoisting working distance, concentrated load needs to be considered according to cable maximum lifting weight plus hoist engine weight, concrete steps are as follows:

(1) The method comprises the steps of adopting a tower crane to mount a tower end, adopting the tower crane to hoist and unlock an anchor head at the upper end of a stay cable on a bridge deck cable laying disc, unloading a nut, expanding the stay cable by a fixed length, and only needing to be a length of a Yu Daduan cable conduit, wherein the stay cable nut is hung on the tower top by the tower crane, a working face is hoisted by a winch in the tower, a hanging strip is tied at a distance from a tensioning end according to the length of the cable conduit, and a traction head is mounted on an anchor cup at the tensioning end;

The method comprises the steps that a reversing point is arranged on a winch in a tower according to the angle of a cable duct of the tower end, a winch wire rope passes through a steering pulley, a cable-stayed tower end nut and the cable duct of the cable-stayed cable to be lowered to a bridge deck, the winch wire rope is connected with an anchor cup of the cable-stayed tower end, the cable-stayed cable is prepared for hoisting and installing the tower end, the cable-stayed cable is slowly hoisted by a crane through the wire rope, a shackle and a hanging strip, the cable-releasing disc synchronously rotates to release the cable-stayed cable, the winch in the tower is hoisted until the upper end of the cable-stayed cable is hoisted to the vicinity of the cable duct of the tower end, the crane hoisting and the traction in the tower are synchronously matched, until the anchor cup extends out of a cable duct, the nut is anchored according to a designed anchoring position, the cable-stayed cable tower end is completed, a traction device in the tower is removed, the tower crane wire rope is removed, and the lashing of the cable-stayed tower end is completed is assembled;

(2) When the lifting requirement of the tower end installation of the cable-stayed cable exceeds the lifting capacity of the tower crane, a tower top hanging frame system is required to be adopted as main lifting equipment for the tower end installation of the cable-stayed cable, when an anchor cup at the tensioning end is pulled below a tower column, the traction is stopped, a connector is arranged at the rear end of the anchor cup, a soft lifting belt is adopted according to the length of a cable guide pipe at the tower end, a lifting point is arranged and connected with a tower crane lifting hook, a lifting point is arranged at a position 10m away from the first lifting point and connected with the tower top hanging frame, a winch steel wire rope in the tower is placed down from the tower, passes through a steering pulley and an anchor cup nut at a corresponding anchor pad in the tower, is led downwards from the cable guide pipe, is downwards connected with a traction head at the beam surface and the rear end of the anchor cup, the tower crane and the tower top hanging frame are started, the anchor cup and the cable guide pipe are matched with a tower crane to carry out tower end hanging, the whole lifting process is borne by the tower top hanging frame, when the anchor cup is lifted to the position of the cable guide pipe at the tower end, the angle of the anchor cup is adjusted, when the angle is consistent, the anchor cup is started to pull the anchor cup into the cable guide pipe, the anchor cup is pulled into the anchor guide pipe, and the anchor cup is pulled at the anchor pad, and the anchor cup is pulled and the anchor position is continuously pulled according to the traction position;

The specific process of the stay cable spreading is as follows:

(1) The short cable adopts a tower crane to spread the cable, the tower crane is utilized to lift the cable to the bridge deck, the cable stayed is transversely moved to a construction section, after the cable stayed falls to a proper length of the bridge deck by a loose hook, the cable stayed is towed to the vicinity of a pipe to be anchored by a bridge deck winch, and the towing distance is in order to meet the installation requirement of the cable stayed tower end;

the nut is detached when the cable is released, the traction device is arranged, preparation is made for installation of the tower end, the cable is directly lifted from the bridge deck, and after the cable leaves the ground, the cable is stopped for a fixed time, and the torsion is released by free rotation;

(2) The long rope adopts a bridge deck rope spreading scheme, the stay rope is bridged and palletized, the tower end is lifted by the tower crane, and the tower end rope hanging process is completed by directly feeding the long rope to the tower in the rope releasing process; after the tower end installation of the stay cable is completed, the residual cable body is still on a cable placing disc, the cable placing disc with the idler wheels is pulled by a winch to be transported, the stay cable is unfolded along the bridge deck, the cable placing trolleys are synchronously installed in the cable unfolding process, and the trolley is placed every 3m to protect the stay cable from being damaged.

Further, in the step 2, after the stay cable is used for finishing tower end installation and cable spreading, beam end installation can be carried out, and the concrete process is as follows:

(1) The traction force of the beam end stay cable is controlled within 50t, and the beam end stay cable anchor head is directly pulled to a designed installation position by matching with a multi-door pulley group through a winch;

(2) Embedding or welding a winch traction pulley block anchoring point after a stay cable at the beam end is embedded into a pipe, wherein the bearing capacity of the anchoring point is larger than calculated traction force;

(3) The bridge deck automobile crane lifts the anchor head at the beam end of the stay cable, unscrews the nut, transfers the nut to the beam end anchoring area, and anchors after the anchor head under the stay cable is exposed out of the anchor backing plate;

(4) A rope clamp and a winch pulley block are arranged at a position which is several meters away from the lower anchor head, and a beam end winch steel wire rope sequentially passes through the beam end fixed pulley block and the stay cable rope clamp to be anchored after passing through the reversing pulley;

(5) Starting a winch to tighten the steel wire rope, and adjusting the anchoring angle by the cooperation of a tower crane, an automobile crane and a chain block to avoid the damage of a stay cable PE layer and a high-strength parallel steel wire caused by the scratch of the stay cable and a cable guide pipe, so that the stay cable enters the embedded pipe along a relatively fixed angle until penetrating through an anchor backing plate to be anchored according to a designed theoretical position;

the specific process of stay cable tensioning is as follows:

(1) The tensioning equipment comprises a jack, tensioning supporting feet, an electric oil pump, a tensioning rod and a reducing sleeve, wherein the actual tensioning force of the stay cable is based on a monitoring instruction, and the tensioning equipment matched with the corresponding level is selected according to one tensioning force;

(2) The tensioning process comprises the following specific steps:

1) Connecting the oil pipes of the oil pump and the jack, checking whether the precision pressure gauge is consistent with the jack, and moving for two strokes under the condition of no load before tensioning, so as to ensure that the jack has no problem during tensioning;

2) Starting an oil pump, slowly moving down the finished rope in the tensioning process, and simultaneously slowly rotating up the anchor ring of the finished rope to ensure that the position away from the anchor backing plate is not higher than a fixed distance;

3) When the design and monitoring of the given tension tonnage are achieved, firstly stabilizing oil pressure, checking whether a cable force value is correct or not, and then screwing the nut to enable the nut to be combined with the anchor backing plate;

4) Finally, removing oil pressure oil return, shutting down, powering off and completing the whole tensioning process;

(3) The specific process of the tensioning construction is as follows:

1) The jack must be calibrated before construction to ensure the accuracy of tensioning control, and when damaged or exceeds a specified service life, the jack should be calibrated again;

2) Symmetrically tensioning the stay cable according to the required cable force and time according to the monitoring instruction;

3) In the tensioning process, the anchor ring of the stay cable cold cast anchor is continuously screwed, so that the damage to the jack and the oil pump caused by the impact of the stay cable when the jack returns oil is prevented;

4) The tensioning process needs to be well tensioned;

5) Stopping construction for the abnormal phenomenon in construction, timely reporting to on-site supervision and design, and continuing construction after taking measures to find out reasons;

6) The stay cable is stretched in a time period with stable temperature, so that errors of measurement, bridge line shape and cable force caused by temperature are reduced;

the specific steps of the cable adjusting are as follows:

(1) The purpose and the times of cable adjusting are to compensate the stress loss in the construction process or correct the errors in the construction, so that the bridge deck line shape and the structural internal force of the full bridge can meet the design requirements to the maximum extent, and the cable adjusting is carried out according to the bridge deck line shape condition in the construction and the monitoring requirement;

(2) The installation of the supporting feet, the installation of the pull rod and the positioning of the jack are the same as the tensioning step, and the step of adjusting the cable is as follows:

1) Adjusting the position of the nut up and down according to the design set tension tonnage so as to achieve the required cable force and bridge deck line shape;

2) When the cable is regulated, after the jack, the supporting feet and the tension rod are installed in place, when the cable force needs to be increased, the jack is used for stretching the stay cable, when the cable force needs to be released, the jack piston is stretched out by a fixed amount in advance before the stress, then the jack is used for moving the tension rod, so that an anchor nut on an anchor head can be just loosened, after an anchor ring is loosened, the jack is unloaded, and the stay cable is discharged out of a cable pipe orifice;

The specific process of vibration reduction of the stay cable is as follows:

(1) Temporary vibration reduction is carried out in the process of adjusting the cable from the completion of the installation of the stay cable to the whole bridge, and the stay cable is vibrated due to the influence of wind load and rain load, so that the main beam is caused to vibrate along with the stay cable, fatigue damage of the root of the stay cable is caused, and the condition of inaccurate measurement construction on the main beam is caused, therefore, the temporary measures are needed to be taken for vibration reduction, and the vibration reduction construction method comprises the following steps:

1) After the construction of each stay cable is completed, temporarily connecting the stay cable with the steel box girder by using CC basket screws;

2) After each stay cable is constructed, the sleeve pipe of the beam end cable is tightly clamped by a conical rubber pad;

3) After the construction of the stay cable part is completed, installing a palm hemp rope temporary auxiliary rope;

(2) After the main girder closure, the stay cable force and the main girder elevation are adjusted, an external damper vibration reduction device is installed at the end of the stay cable beam according to design requirements, and a double spiral line is arranged on an outer layer protection sleeve of the stay cable so as to reduce the influence of wind and rain vibration.

Further, the specific process of the closure posture adjustment in the step 3 is as follows:

1) And after the side span support is removed and the bridge deck load treatment is completed, the posture of the closure opening is adjusted. When the posture of the closure mouth is observed, the posture of the closure mouth during measurement is required to be the same as the posture of the closure section after lifting;

2) Closure posture adjustment includes: the vertical section shape of the closure mouth, and the elevation and the axis of the GXL19 beams Duan Qian on two sides are adjusted;

3) The closure mouth elevation adjusting measure is to adjust the length of a Z18-Z19 stay cable of a midspan, and adjust the left and right amplitude elevations of the front ends of the steel beams at two sides to the same elevation, namely, the elevation is designed after lifting;

4) The adjustment of the axis of the closure opening is completed through auxiliary facilities arranged on top plates of beam sections of GXL19 on two sides, the auxiliary facilities consist of temporary lifting lugs, steel wire ropes, chain blocks and shackles, 4 blocks are obliquely pulled oppositely during adjustment, and the axes of the steel beams on the two sides are adjusted to the same axis;

5) In order to reduce the temperature influence, the precise adjustment of the shape of the closure mouth is carried out at night or in overcast and rainy days with constant temperature;

6) After the adjustment is finished, transverse locking is carried out, and after that, no other load is generated at the front end of the steel box girder;

the closure mouth monitoring comprises monitoring of temperature and monitoring of closure mouth width, and the specific process of closure mouth monitoring is as follows:

1) The state of the closure mouth is very sensitive to temperature change, the risk that the closure section cannot be embedded into the closure mouth or the welding seam is too wide exists, the closure mouth state needs to be monitored closely to ensure the controllability of the midspan closure, and the observation purpose is to find the closure section length corresponding to the temperature during the predicted closure by adopting a regression analysis method;

2) The main observation contents comprise the width of a closure top bottom plate and the relative elevation of 5 beam sections at the front end of a cantilever, cable temperature, tower temperature, liang Wen and air temperature are matched for observation when the closure width is observed, cable temperature, liang Wen and tower temperature are measured once when the closure width is measured, so that a monitoring unit is convenient to correct and predict the temperature, and cable force measurement is matched in a temperature stabilizing time period;

3) The width measurement of the closure mouth is carried out by adopting a hand-held laser range finder, the closure temperature and the closure mouth width are determined according to the monitoring data, and the shape and the length of the finish machining of the closure section are determined;

4) When the bridge deck crane is in place, the hanger is replaced, the temporary bridge deck load is cleaned, and the Z19 stay cable is completed;

5) The parameters of the front three sections of beams Duan Gaocheng and the axes of the mid-span cantilever end are observed in response to the environmental temperature and the structural temperature field and the width of the closure mouth;

6) The observation of the width of the closure mouth is to continuously observe the distance between the top mouth and the bottom mouth of each GXL19 Liang Duanjian at two sides in a fixed time period, and simultaneously, the environment temperature, the concrete temperature of a cable tower, the top plate and the bottom plate of a steel box girder are synchronously and continuously observed to obtain the law of the change of the form of the closure mouth along with time and temperature, and reliable marks are arranged at the positions of measuring points to ensure the unification of the observation positions;

7) The observation time period is 24 hours from 19 to 19 hours in the evening, and is basically observed once every 1 hour in the evening and once every 2 hours in the daytime;

8) The steel box girder top plate is provided with 5 observation points which are respectively positioned at the position of the side middle web plate and the girder axis; the bottom plate is provided with 5 observation points which are respectively positioned at the positions of the side middle webs and the intersection points of the bottom plate and the inclined bottom plate;

the specific process of the closure section is as follows:

1) On the basis of reserving machining allowance in a closure section factory, a steel box girder manufacturing unit performs accurate blanking, matched cutting on the closure section on site of a bridge position according to closure temperature and closure section matched cutting length determined by continuous observation, so that the length of the closure section, the matched cutting angle of the end part of the closure section and the included angle of the length corresponding to the posture of the girder on site are consistent;

2) The closure section is manufactured by increasing the length of a designed beam by 40cm in advance when being processed by a steel beam manufacturing factory, single-end matched cutting is adopted when the closure section is hoisted, one side is used as a matching end, and the other end is used as a matched cutting end;

3) The closure section reaches the field in advance, and after the distribution cutting length is obtained, distribution cutting is carried out on a transport ship on site, electric welding and gas cutting equipment are needed to be prepared on the ship, and a power supply is needed to be prepared;

4) A steel rule is adopted for matching, cutting and length measurement lofting, the steel rule is required to be corrected with a hand-held laser range finder during observation, and the temperature during matching, cutting and lofting of a closure section is required to be close to closure temperature, so that the temperature influence is avoided;

5) When the temperature difference between the matching cutting and closure is 5 ℃, hoisting closure is carried out;

the concrete process of the closure section hoisting is as follows:

1) Hoisting operation of closure segments is carried out in favorable weather, preferably in overcast and rainy weather with constant temperature and gust wind speed at the bridge deck elevation of not more than 20m/s;

2) Lifting the closure section to the bottom of the closure opening in the daytime, lifting the beam into the closure opening in the day of 19:00-21:00, and pulling out temporary wind-resistant stabilizing measures after the closure section is stopped in the air;

3) Before the crane is unhooked, a bridge deck crane driver and field technicians check the crane;

4) A barge for transporting the beam section on the water is stopped at an area right below a bridge deck crane, the beam Duan Ying is horizontally placed in place, the positioning error of the transporting Liang Bochuan is not more than +/-2.0 m, after anchoring and stabilizing for 10 minutes according to an anchoring scheme, hoisting personnel begin to carry out boarding operation, 8 hoisting tool steel wire ropes are placed on the top surface of the lifting beam section, and a hoisting tool is used for connecting temporary lifting lugs on the steel beam;

5) Before hoisting, the hoisting field command should be fully checked with a bridge deck crane driver, operators and field technicians on a transport Liang Bo ship, and after the crane and the steel beam are determined to be correct, the formal hoisting is started;

6) When the closure section is lifted, four cranes at two sides of the closure opening are synchronously carried out;

7) In the lifting process, four cranes are synchronously coordinated, and leveling is carried out on a beam section every 5 minutes of lifting; the relative height difference of four corners of the closure section is measured at regular time by adopting a handheld laser range finder, the steel box girder of the closure section is adjusted to be horizontal in time, unbalanced stress is avoided as much as possible, and the two handheld laser range finders need to be corrected in advance;

8) When the closure section approaches the closure opening bottom plate by about 10cm, suspending lifting;

9) When the closure section is hoisted below the closure opening bottom plate, the closure section and the GXL19 beam section are temporarily fixed by adopting a steel wire rope and a chain block, a stress point is arranged at the position of a longitudinal baffle plate, temporary lifting lugs are welded on the top surface of the closure section top plate and the top surface of the GXL19 beam section bottom plate, and are tensioned and fixed by the steel wire rope and the chain block;

10 When the width of the closure opening is proper, starting the crane lifting device to enable the closure section to be accurately embedded into the closure opening;

11 During the process of embedding the closure section into the closure opening, arranging chain blocks at two ends of the side web plates for assistance, and arranging 4 sets of 5t chain blocks at each side;

12 After the closure section is embedded into the closure opening, a temporary matching positioning screw rod is installed to finish the lifting of the closure section;

13 The mid-span closure beam section can be lifted to the bottom of the closure mouth in daytime, and the beam section is lifted into the closure mouth at night when the temperature is set;

14 After the connection of the midspan closure section and the cantilever beam sections at the two sides is completed, the temporary consolidation at the position of the lower beam of the cable tower is released, and the system conversion is completed

15 During the process of embedding the closure section into the closure opening, correction is carried out through auxiliary measures such as single action of the crane, crow bars, chain blocks and the like, after the closure section is embedded into the closure opening, the temporary matching positioning screw rods at the two ends of the installation are adjusted, and if the movable fire repair holes exist when the two north ends cannot be installed simultaneously.

Further, the specific process of matching the beams Duan Jingdu in the step 3 is as follows:

1) After hoisting the primary position, immediately starting matching of the matching ends;

2) The elevation of the top surface and the beams Duan Pingji on the two sides are adjusted by 4 bridge deck cranes;

3) The width of the welding seam is adjusted by tightness of positioning screws at two sides, and the axis is adjusted by a chain block;

4) The matching ends of the closure segments are accurately matched, so that the width of welding seams at two sides is uniform, the width of the welding seams meets the welding requirement, the butt joint smoothness of fracture at two sides is ensured, and especially the top pair Ji Shunzhi of the side longitudinal webs is ensured;

the specific process of the matching end code determination is as follows:

1) A large code plate is adopted as a locking device;

2) After finishing the fine adjustment of the matching end, adopting a large code plate as a locking device to weld and fix the matching end of the closure section and the installed beam section, so as to prevent the beam Duan Yidong;

3) Simultaneously, temporarily welding the other side beam section at the matched cutting end by using a large code plate;

4) The large stacking plates are arranged strictly according to the drawing positions, the stacking plates are arranged in sequence, namely a web plate, a top plate and a bottom plate are stacked symmetrically from the middle to the two sides;

the specific process of the fixed closure mouth of the matched cutting end is as follows:

1) Fixing a closure port at the side of the matched cutting end, welding the other side of the large code plate with the steel box girder, ensuring that the welding is finished within half an hour, then carrying out local leveling work, immediately starting welding of the steel box girder by leveling, and synchronously starting welding at the two ends of the closure section;

2) Before 7 points on the second day, web welding and backing welding of the top plate and the bottom plate are completed;

3) After welding is completed, the bridge deck crane is unhooked and retreated, the bridge deck crane is dismantled, and the length of the Z19 cable is recovered to the length of the secondary tensioning cable;

the system conversion comprises the following specific processes:

after the prestressed steel bundles of the steel-concrete combination section are stretched, temporary consolidation constraint is set at the junction of the tower beams, after temporary locking is completed when the midspan steel box beams are closed, in the same period of welding of the splice joints of the closed beam sections, when the welding work of the parts with larger rigidity such as the main circumferential joints or the main webs is completed, the temporary consolidation among the tower beams is released in time.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

According to the invention, the temperature is detected in real time in the folding process, and then folding and installation are carried out according to the temperature data, so that the installation accuracy is higher, meanwhile, two vibration reduction devices are arranged on the stay cable, and the main beam vibrates along with the stay cable, so that the situations of fatigue damage of the root of the stay cable, inaccurate measurement construction on the main beam and the like are caused.

Drawings

FIG. 1 is a flow chart of the steel beam installation matching of the present invention;

FIG. 2 is a flow chart of the stay cable construction process of the invention;

FIG. 3 is a temporary vibration damping layout of the stay cable of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below by referring to the accompanying drawings and by illustrating preferred embodiments. It should be noted, however, that many of the details set forth in the description are merely provided to provide a thorough understanding of one or more aspects of the invention, and that these aspects of the invention may be practiced without these specific details.

As shown in fig. 1-2, a bridge steel structure installation construction folding method comprises the following steps: the method comprises the steps of hoisting beam sections, fine matching and temporary connection, wherein a two-point hoisting method is adopted in the beam Duan Qi hoisting, the position of the beam sections is accurately calibrated by using a theodolite before each beam section is hoisted, a sling positioning test is carried out, after positioning adjustment, hoisting is carried out again to prevent the beam sections from deviating in position to generate transverse swinging, 39 transition beam sections and standard beam sections of the steel box beam are subjected to point-to-point hoisting by adopting a bridge deck crane, and the hoisting of each standard beam section comprises the steps of beam Duan Disheng, beam Duan Chu matching, beam Duan Jing matching and beam Duan Gong ground connection and load transfer from the bridge deck crane to a stayed cable.

the specific process of lifting the beam section in the step 1 is as follows:

The specific process of the initial matching of the beam section in the step 1 is as follows:

The specific process of beam section fine matching in the step 1 is as follows:

The concrete process of the bridge section construction site connection and load transfer from the bridge deck crane to the stay cable in the step 1 is as follows:

2) Installing and tensioning corresponding stay cables for the first time;

5) A forward crane;

And (3) steel beam installation matching flow:

step 1: as shown in a of fig. 1, (1) construction preparation; (2) anchoring and positioning Liang Chuan; (3) the bridge deck crane lowers the shoulder pole beam to the position of the beam section to be lifted. (3) Connecting the shoulder pole beam with a beam section to be hoisted; (4) adjusting the position of the hanging point to ensure the girder to be lifted horizontally; (5) and connecting the shoulder pole beam with the bridge deck lifting lug by using a lifting belt. Checking the conditions of the crane and the lifting lug, so that each lifting point is uniformly stressed; (6) the bridge deck crane slowly lifts the beam section; (7) after the beam section is adjusted away from the beam transporting ship, the beam transporting ship is driven away; (8) the bridge deck crane continues to lift, and the beam section is kept to rise horizontally.

Step 2: as shown in B in fig. 1, (1) the beam section is lifted to near the deck to stop lifting; the beam Duan Zhi is hoisted by an amplitude mechanism on the crane 50mm from the installed beam Duan Bianyuan mm. (2) Adjusting a bridge deck leveling cylinder on the longitudinal shoulder pole beam to adjust a bridge deck longitudinal slope to be matched with the installed beam Duan Da; (3) repeating the longitudinal and transverse adjustment and matching until the axis is connected with the installed beam section, then inserting and beating temporary matching piece punching nails, installing matching piece bolts and tightening, locking the lifting jack, and completing primary matching.

Step 3: and (1) carrying out local linear measurement of the main girder at the front end of the cantilever, and comparing control instructions to determine the longitudinal slope adjustment quantity of the hoisting main girder as shown in C in figure 1. (2) The Liang Duanjian bolts and jacks are trimmed to make the beams Duan Zhouxian and elevations meet the requirements, completing the matched.

Step 4: as shown in D of fig. 1, (1) completing the connection between the lifting beam segment and the installed beam Duan Jiefeng; (2) and installing and tensioning the corresponding stay cable for the first time according to the requirements. (3) Starting the continuous jack, and removing the steel wire rope hanging rope for connecting the shoulder pole beam and the beam section. (4) Lifting the shoulder pole beam by using a lifting jack to adjust the shoulder pole beam away from the beam section; (5) the bridge deck crane moves forward; (6) tensioning the corresponding stay cable for the second time; the next beam section is ready for installation.

Welding process requirements of construction site

1) The butt joint must be derusted before welding, and the welding must be performed within 24 hours after derusting in order to prevent the butt joint from being rusted again or contaminated.

2) The site positioning welding is required to be more than 30mm away from the end part of a designed welding line, the length is 50-100 mm, the residual height is not less than 5mm, the welding line is not allowed to have defects, and the two ends of the welding line are ground into gentle slopes by using grinding wheels.

3) And welding according to the requirements of the welding operation regulations of the construction site.

4) To reduce the additional stresses resulting from welding, the weld residual stresses and the localized stresses of the edge material, and eliminate or reduce irregular deformations, the girth weld must be welded in a prescribed welding sequence.

5) The stiffening of the bottom and the web adopts the form of a reinforcing block, the welding of the transverse butt joint circular seam of the bottom plate is firstly carried out, and then the reinforcing block is installed and welded.

6) The welding environment temperature of the construction site is preferably above 5 ℃ and the relative humidity is below 80%.

7) When the construction site is welded, a windproof facility is arranged to cover all welding positions, except that the inside and outside of the box girder cannot be welded in rainy days, and when CO2 gas shielded welding is adopted in the welding of the box girder, a ventilation protection safety facility is required to be used.

And (3) welding the beam sections on the construction site in a welding sequence, and after the beam sections are lifted in place, adjusting welding gaps and then welding. Welding sequence of beam sections: butt joint of box girder bottom plates, butt joint of box girder webs, butt joint of box girder panels, reinforcing rib embedding butt joint and reinforcing rib embedding corner joint.

The top plate high-strength bolts are connected, the U ribs of the top plate of the steel box girder and the plate stiffening ribs are connected by high-strength bolts, S10.9-level M22 multiplied by 80 high-strength bolts are adopted, each construction site is connected with 2080 sets, and the total number of the construction site is 40.

(1) Bolt screwing step

1) When the high-strength bolts are screwed, the large-area node plates are screwed from the middle part to the peripheral edges according to a certain sequence from the positions with large rigidity and large gaps of the plate bundles, and the screwing is finished at the end of the day; when the screw is applied, the screw cannot be operated in a manner of impact screw and intermittent screw. The large hexagon head high strength bolt is screwed, and torque is only applied to the nut.

2) The torque wrench adopted by the high-strength bolt screwing should be calibrated before and after the operation, and the torque error of the torque wrench should not exceed +/-5% of the torque value used.

3) When the high-strength bolt connection pair is twisted by adopting a torque method, primary twisting, secondary twisting and final twisting are completed in the same working day.

(2) Determination of torque performance parameters for high strength bolts Shi Ning

1) Before the construction of the high-strength bolt connection pair, the torque coefficient of the high-strength bolt connection pair is rechecked according to factory batches, and 8 sets of the torque coefficient are rechecked in each batch. The average value and standard deviation of the 8 sets of torque coefficients meet the design requirement, the average value deviation is between 0.110 and 0.150 when the design is not required, and the standard deviation is smaller than or equal to 0.010; the measured data should be taken as the main parameter for the application.

2) The construction torque of the high-strength bolt is calculated and determined by the following formula:

Tc＝k·Pc·d

wherein: tc, construction torque (N.m); k, the average value of the torque coefficient of the high-strength bolt connection pair, which is measured by experiments; pc-high strength bolt construction pretension (kN), see Table 1;

d-the nominal diameter (mm) of the high strength bolt.

Table 1 shows a pretension meter for high strength bolts

3) And (5) determining construction torque and calibrating a torque wrench. The initial twisting torque is controlled according to 50% of the final twisting torque, the final twisting torque is filled in according to the calculation of a laboratory, and a high-strength bolt twisting torque control notice is issued. After receiving the notice, the field technician should check and sign to confirm, and apply the control torque control bolt Shi Ning on site according to the notice. The torque wrench for construction of the high-strength bolt is calibrated by a laboratory before and after the work, the calibrated wrench is labeled at the calibrated dial, the calibration time and the calibration person are noted, any person on the construction site cannot tear the label, and the calibrated dial cannot be adjusted without permission. The calibration torque error must not exceed + -5% of the control torque value. If the errors are found to be out of range in the post-shift calibration, all bolts screwed by the wrench are judged to be unqualified, the wrench is calibrated again, and screwing is performed again. At this time, the laboratory should immediately report the technical responsibility.

Step 2: the stay cable construction comprises the steps of construction site preparation, stay cable upper bridge, stay cable tower end installation, stay cable expanding, beam end installation, stay cable tensioning, cable adjusting and stay cable vibration reduction.

The concrete process of the preparation work of the construction site in the step 2 is as follows:

(1) The preparation work in the tower box comprises the following steps:

The concrete process of the stay cable upper bridge is as follows:

The specific process of the stay cable spreading is as follows:

In the step 2, the beam end installation can be carried out after the stay cable is used for completing the tower end installation and cable spreading in the beam end installation, and the concrete process is as follows:

the specific process of stay cable tensioning is as follows:

(2) The tensioning process comprises the following specific steps:

(3) The specific process of the tensioning construction is as follows:

4) The tensioning process needs to be well tensioned;

the specific steps of the cable adjusting are as follows:

The specific process of vibration reduction of the stay cable is as follows:

(1) Temporary vibration reduction is carried out in the process of adjusting the cable from the completion of the installation of the stay cable to the whole bridge, and the stay cable is vibrated due to the influence of wind load and rain load, so that the main beam is caused to vibrate along with the stay cable, fatigue damage of the root of the stay cable is caused, and the condition of inaccurate measurement construction on the main beam is caused, therefore, temporary measures are needed to be taken for vibration reduction, the temporary vibration reduction measures are shown in fig. 3, and the vibration reduction construction method comprises the following steps:

The specific process of the closure posture adjustment in the step 3 is as follows:

the specific process of the closure section is as follows:

the concrete process of the closure section hoisting is as follows:

The specific process of beam Duan Jingdu matching in step 3 is:

the specific process of the matching end code determination is as follows:

1) A large code plate is adopted as a locking device;

the system conversion comprises the following specific processes:

after the prestressed steel bundles of the steel-concrete combination section are stretched, temporary consolidation constraint is set at the junction of the tower beams, after temporary locking is completed when the midspan steel box beams are closed, in the same period of welding of the splice joints of the closed beam sections, when the welding work of the parts with larger rigidity such as the main circumferential joints or the main webs is completed, the temporary consolidation among the tower beams is released in time. Main preparation work before hoisting:

1) The monitoring on the aspects of the bridge formation line shape, the cable force, the tower deflection, the stress and the like is enhanced by three sections in advance, and the parts which do not meet the requirements are timely adjusted.

2) And tensioning the stay cable, and after the bridge deck crane is disassembled and replaced, the shoulder pole beam moves forwards, and a closure channel (one of the upstream and the downstream and one of the end of which are fixed) is erected on the tuyere of the beam section.

3) And (3) temporarily ballasting steel box girders on two sides of the closure mouth, wherein the loading capacity of each side is half of the dead weight of the closure girder section, the ballasting is performed by adopting a water tank to add water, and the water tank is arranged near webs on two sides of the bridge deck crane (the mid-span deflection can be reduced).

4) The method is characterized in that reasonable time is selected, accurate positioning is carried out on the beam sections at the two sides according to monitoring requirements, the difference of elevation of symmetrical control points of the beam sections at the two sides meets the requirements (relative offset of axes is not adjustable and is finished before welding the beam sections at the two sides), then a stiff framework is welded at the outer sides of webs of the beam sections at the two sides in time, and a chain block is hung on the top of the beam to be crossed and obliquely pulled to ensure that box beams at the two sides are relatively fixed at the transverse and vertical positions. In the beam section positioning process, if the shaking is large, the auxiliary positioning of the adjusting beams can be realized by arranging adjusting beams on the top and the two sides of the beam.

5) The stiff skeleton is truss structure, and its main string adopts by shaped steel welded box roof beam, in order to adapt to the change of closure mouth width, and the one end design of stiff skeleton is scalable structure, and the stiff end of stiff skeleton can be welded fastening on the roof beam section earlier before the roof beam Duan Jingque is located. Due to the influence of the stiff framework, the tuyere of the closure girder section is assembled on site.

6) Measuring points (measuring point positions are determined according to monitoring requirements) are distributed on two side beam sections of the closure opening, one day with smaller wind power is selected, closure opening distance and elevation of adjacent box beams are measured every two hours, and simultaneously, atmospheric temperature and box beam internal surface temperature are measured, and continuous observation is carried out for 1-2 days and nights. And determining the actual length and closure time of the closure beam section according to the actual measurement data, and cutting the allowance of the closure beam section.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. A bridge steel structure installation construction closure method is characterized in that: the method comprises the following steps:

2. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the specific process of lifting the beam section in the step 1 is as follows:

3. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the specific process of the initial matching of the beam section in the step 1 is as follows:

4. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the specific process of beam section fine matching in the step 1 is as follows:

2) Installing and tensioning corresponding stay cables for the first time;

5) A forward crane;

6. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the concrete process of the preparation work of the construction site in the step 2 is as follows:

(1) The preparation work in the tower box comprises the following steps:

the concrete process of the stay cable upper bridge is as follows:

the specific process of the stay cable spreading is as follows:

7. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: in the step 2, the beam end installation can be carried out after the stay cable is used for completing the tower end installation and cable spreading in the beam end installation, and the concrete process is as follows:

the specific process of stay cable tensioning is as follows:

(2) The tensioning process comprises the following specific steps:

(3) The specific process of the tensioning construction is as follows:

4) The tensioning process needs to be well tensioned;

the specific steps of the cable adjusting are as follows:

The specific process of vibration reduction of the stay cable is as follows:

8. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the specific process of the closure posture adjustment in the step 3 is as follows:

the specific process of the closure section is as follows:

the concrete process of the closure section hoisting is as follows:

9. The bridge steel structure installation construction folding method according to claim 1, wherein the method comprises the following steps: the specific process of beam Duan Jingdu matching in step 3 is:

the specific process of the matching end code determination is as follows:

1) A large code plate is adopted as a locking device;

the system conversion comprises the following specific processes: