1450 results about "Cable stayed" patented technology

The invention discloses an identification method of fundamental frequency for detection of the force of the cable of a stayed-cable bridge, which gets a first fundamental frequency by an autopower spectrum module, a second fundamental frequency by a cepstrum module, and then determines whether the quotient of the following two values is less than or equal to the set threshold: 1. the absolute value of the difference of the first fundamental frequency and the second fundamental frequency; 2. a half of the sum of the first fundamental frequency and the second fundamental frequency. In this way, whether the fundamental frequency of the pull cable is a half of the first fundamental frequency and the second fundamental frequency is determined. By adopting the method, the accuracy and the precision of the fundamental frequencies got are significantly improved. In addition, as the vibration acceleration response time interval signal got by an acceleration sensor passes through a signal conditioning module for filtration and smooth processing firstly, the environmental noise in the vibration acceleration response time interval signal is effectively suppressed; the antijamming capability of the stayed-cable bridge is improved so that the fundamental frequency is identified more clearly and accurately.

The invention discloses a spiral line cable detecting robot which consists of a cart, an upper and a lower supporting hugging devices symmetrically distributed along the cable which are connected together. The robot is characterized in that the active cart is provided with a climbing device and a magnetic absorbing device; two supporting horizontal levers are provided with hugging devices; the climbing device includes a lithium battery fixed in the cart and a DC motor fixed on one side of the driving wheel in the cart; power of the DC motor is supplied by the lithium battery, and the DC motor drives the driving wheel of the cart to rotate by a drive axle, so as to drive the whole robot to spirally climb along a water transmission line of the cable; the hugging devices and the magnetic absorbing device work together to tightly press the driving wheel onto the surface of the cable. The climbing device can rotate for any degree relative to the cart, so as to adapt to the water transmission line with different thread pitch; power supply by the lithium battery is more suitable for the environment of high-altitude operation; the robot is also provided with a descending device, which is safer and more reliable in use. The invention has simple and reasonable structure, is convenient in maintenance, can have high climbing speed, is applicable in detection of the spiral line cable of large cable-stayed bridges as well as lamps and other rod types.

The invention relates to a three-truss main girder structure of a highway and railway bi-purpose cable-stayed bridge and an installation method thereof, relating to the technologies of designing and constructing a heavy load and long span highway and railway bi-purpose cable-stayed bridge. The structure of three main trusses comprises a middle truss piece and side truss pieces arranged on both sides of the middle truss piece, wherein an orthotropic slab and a transverse bracing truss are arranged between the upper edges of the middle truss piece and each side truss piece, and a railroad transverse girder, a railroad longitudinal girder and a horizontal bracing cross bridging are arranged between the lower edges of the middle truss piece and each side truss piece; and the invention provides the installation method adopting adaptive pre-splicing of multiple truss-sections, arrangement of temporary constructional rod pieces, integral lifting of each truss section and multi-node simultaneous alignment. The invention has the beneficial effects of: 1. pushing the highway and railway bi-purpose cable-stayed bridge to develop towards the direction of large span and heavy loading, 2. improving the installation efficiency and quality, 3. reducing the quantity of welding lines of construction sites, 4. innovatively practicing the multi-point simultaneous butt joint technology, 5. adopting the temporary rod pieces for solving the problems of unstability and large deformation in the processes of delivering and lifting the truss sections, 6. strengthening the adaptability of adjacent truss sections, and 7. solving the problems of inconsistent deformation of the middle and the side trusses and inconsistent centre-of-gravity positions of the truss sections.

The invention provides an integrated frequency difference method of a cable stayed bridge cable tension test. The method comprises the following steps: firstly, reading three frequency values fi, fj and fk which are corresponding to a first peak, a second peak and a third peak in an auto-power frequency spectrum graph of a tested cable actual measurement acceleration time history; secondly, obtaining a fundamental frequency initial value f by utilizing the three frequency values corresponding to the three peaks; thirdly, determining a possible order corresponding to each frequency; finally, determining basic frequency fv and cable tension T. According to the invention, calculation is simple, operation is carried out according to a process, other complex determination and processing processes are not needed, result accuracy is raised, technology difficulty in a cable tension test is substantially reduced, by employing the method, high efficiency is realized, data analysis processing time can be saved, test cost is reduced, and economy is good.

The invention discloses a streamlined steel-concrete superimposed box girder, which relates to the technical field of bridge engineering and is used for a long-span bridge girder. Two sides of the superimposed box girder are provided with tuyere structures, and a bridge panel adopts a superimposed structure consisting of prefabricated concrete slabs and a post-poured concrete layer. When the box girder is in use, the superimposed box girder is a streamlined single-box single-chamber or single-box multi-chamber cross section; the tuyere structures are polygonal open thin-walled structures; and longitudinal-transverse prestress is applied in the superimposed bridge panel. The box girder effectively improves the torsional rigidity and wind-resistant stability of the section of the girder, remarkably improves the integrity and durability of the bridge panel, and expands the application of superimposed girders in cable-stayed bridges and other long-span bridges.

The invention relates to a large span steel box girder cable-stayed bridge tower lower beam segment mounting method, belonging to the bridge construction steel box girder construction technology field. The construction method comprises the steps: (1) setting up a masts type crane lifting tower area steel box girder by means of the upper crossbeam of the cable tower and the construction wind; (2) mounting the bridge deck crane in on the tower area steel box girder and lifting the first standard beam segment immediately adjacent to the tower area steel box girder; (3) mounting the bridge deck crane symmetrically on the mounted first standard beam segment, and starting the standard beam segment symmetrical hanging on both the river side and the bank side. The method in the invention achieves the advantages of simple, practical, safe, reliable, economic, convenient less limited by the construction condition, solves the problems in present large span steel box girder cable-stayed bridge construction process.

The invention relates to a corrugated steel webplate combined box girder floor system for a cable-stayed bridge and a construction method thereof, and belongs to the technical field of bridge structures. The corrugated steel webplate combined box girder floor system comprises a precast concrete plank and a cast-in-place concrete seam, wherein the precast concrete plank is positioned on a steel box girder and is integrated with the steel box girder into a whole; the steel box girder is formed by welding a top flange steel plate, a corrugated steel webplate and a steel plate at the bottom of the box girder; a box girder baseplate stiffening rib and a diaphragm plate are welded in the steel box girder; the diaphragm plate comprises a top flange steel plate of the diaphragm plate and a steel webplate of the diaphragm plate; a toggle pin connecting piece is welded on the top flange steel plate and the top flange steel plate of the diaphragm plate; and a steel anchor pulling plate and a steel sleeve are welded on the top flange steel plate. The corrugated steel webplate combined box girder floor system simplifies the manufacturing process for the precast concrete plank, gives full play to the superior mechanical property of the corrugated steel webplate and the release action of the corrugated steel webplate on the creep effect of concrete shrinkage, improves the bearing capacity, stiffness and crack resistance of the structure, and improves the durability of the structure.

The invention relates to a stay cable stay force measuring method based on a vibration method using a linear model which belongs to the technical field of construction engineering. The method provided in the invention aims to solve problems of prior art. The problems are illustrated as follows. In the prior art, a stay force measuring method, normally based on the assumption of a specific physical model, is difficult to realize a unified recognition of various stay forces and in different measuring methods, the definition of parameters also varies. It is also difficult to operate to mix different measuring methods for use. All these factors undermine measuring accuracy. The method of the invention is carried out as follows. Tensioning a stay cable with two grades of pulling forces; under each grade of pulling force, using a speed accelerator sensor to measure the speed acceleration signals under the action of environment excitation or people excitation; converting the signals into auto power spectrum patterns; substituting each grade frequency of the two grades of pulling forces and the tensioning force into a linear model; identifying linear model coefficients corresponding to each grade frequency and realize the recognition of model parameters. The recognized linear model and the natural vibration frequency of each grade make it possible to recognize the stay cable stay force. With the method provided in the invention, a relatively-high-accuracy measuring value of stay force can be achieved and the problem of recognizing physical parameters to measure stay force using a traditional vibration method can be avoided, thus making the method reduce the uncertainty of a stay force test.

The present invention relates to a method for constructing a cable-stayed bridge with a tensionless stay cable, including the steps for: constructing a main tower 100, continuously installing a suspension cable 200 over a main span and a side span, installing a plurality of hangers 210 on the suspension cable 200, arranging an anchorage cable 220 in a longitudinal direction by connecting the anchorage cable 220 to a lower end of the hanger 210, installing a stay cable 110 in sequence, constructing a girder by connecting a segment 300 constituting the girder to each of the stay cables 110 in sequence, and connecting the segments 300 one another in a longitudinal direction, and removing the suspension cable 200, the hanger, and the anchorage cable 220.

The invention discloses a support system for a long-span cable-stayed bridge, which relates to the technical field of bridge engineering. The support system consists of nine parts including main girders, bridge towers, stay cables, transitional piers, transverse wind resisting bearings, longitudinal viscous dampers with limiting function, longitudinal sliding bearings with limited transverse rigidity, transverse dampers, and telescopic devices. Compared with the prior support system for the long-span cable-stayed bridge, the support system of the invention has the characteristics that the longitudinal viscous dampers with limiting function are arranged between the main girders and the bridge towers; and the longitudinal sliding bearings with limited transverse rigidity and the transverse dampers are arranged between the main girders and the transitional piers. The support system provides effective rigidity and damping for the long-span cable-stayed bridge to ensure that the static force and the dynamic force responses of the bridge are controlled in an acceptable scope; the structural stress is definite; and the applicability is strong.

The invention discloses a bondbeam cable-stayed bridge sensor layout method based on two-phase multi-scale model correction. By establishing a fine finite element model of a full bridge structure, the part easy to damage of the whole structure is determined, then the multi-scale finite element model with the part easy to damage being small-scale and other parts being large-scale is established, then the power characteristic of a real bridge is obtained through an environmental vibration test; the bondbeam cable-stayed bridge multi-scale finite element model is corrected by adopting a two-phase correspondence face method, a finite element model further approaching the structure of the real bridge is obtained, then the part easy to damage of the whole structure as well as monitoring content and monitoring position on structure overall correspondence analysis level are determined, and finally the layout sorts and layout positions of the sensors on the bondbeam cable-stayed bridge are determined. The bondbeam cable-stayed bridge sensor layout method ensures that a bondbeam cable-stayed bridge health monitoring sensor system is more reasonable, reliable and effective, and further faciliates the accuracy of the safety early warning and safety prevention of bridge health monitoring.

The invention relates to a bridge intelligent cable system with a built-in fiber grating sensor, which is used for cable bearing structures of a cable-stayed bridge, a suspension bridge, an arch bridge and the like. The bridge intelligent cable system comprises an anchoring cup (1), a dividing plate (5), a connecting cylinder (4), a fiber grating sensor and a cable body (11), wherein the fiber grating sensor comprises a fiber grating strain sensor (9) and a fiber grating temperature sensor (10), tail fibers of the fiber grating strain sensor (9) and the fiber grating temperature sensor (10) are led out, the packaged fiber grating strain sensor (9) is fixedly connected to an outer steel wire (3) at the position of the connecting cylinder (4), the packaged fiber grating temperature sensor is suspended on the steel wire (3) at position of the connecting cylinder (4), a hole (5-1) is penetrated in the dividing plate (5), and preserved steel pipes (7) are primarily imbedded in the connecting cylinder (4) and the anchoring cup (1) in advance. The invention can improve the survival rate of the fiber grating sensor and the optical fibers during the manufacture and the application of the cable, ensure a reliable embedding process of the fiber grating sensor and effectively lead fiber grating signals out of the cable body in a distortionless way.

The invention discloses a method for construction of a high upper beam steel oblique leg prestress support of an H-shaped cable bent tower of a cable-stayed bridge and belongs to the field of bridge construction. According to the method, a steel oblique leg bracket and a lagging jack are adopted for construction of a beam, installation and dismantling of a large number of steel pipe supports when a high support construction method in the prior art is adopted are avoided, the workload of pre-buried piece installation during cable bent tower construction and the workload of repair in the later stage are reduced, the high-altitude welding workload and materials are reduced, the risk of aloft work is greatly reduced, and the problem that the reserved compression amount of the high support and the camber of a pre-buried bracket support are difficult to set is solved; stress of the steel oblique leg bracket is clear, an upper joint transmits a vertical load to the cable bent tower, the horizontal outward component force of obliquely-downward force on a lower joint is counteracted by prestressing force pre-applied by a prestress wire close to a horizontal tie bar, and the vertical component force of the obliquely-downward force on the lower joint is borne by the cable bent tower. In addition, the cable bent tower and the beam are constructed asynchronously, a cable bent tower formwork does not need to be constructed on the side provided with the beam, high-altitude dismantling and installation of a climbing fame are omitted, the safety risk is lowered, and the construction cycle is shortened.

The invention discloses an FFT data correction method in the detection of the stay cable force of a cable-stayed bridge with a frequency method; an acceleration sensor is arranged on a stay cable and connected with a control box; a fundamental frequency generation module is arranged inside the control box; the fundamental frequency generation module comprises an FFT module, a waveform correction module and a secondary FFT module; the acceleration sensor captures a time-domain vibration signal of the stay cable and inputs the signal into the control box; the time-domain signal is then processed through FFT spectral analysis by the FFT module, so that the spectrum curve of the signal can be obtained; the data of the frequency within 7.5-25Hz on the spectrum curve is kept, while the remaining data is made zero; after the data of the frequency within 7.5-25Hz obtained in the third step is processed through secondary FFT transformation analysis by the secondary FFT module, the fundamental frequency of the stay cable of the cable-stayed bridge can be detected. Through the FFT spectrum analysis data correction and the secondary FFT transformation, the invention can accurately detect the fundamental frequency of the stay cable of the cable-stayed bridge and eliminates the abnormal phenomena due to the cable force detection through a frequency method.

The invention relates to a brand-new construction method of a mixed combined girder cable-stayed bridge. After the construction of the main tower, auxiliary piers, side piers, main bridge side span concrete beams and approach bridges, the mid-span steel girder members and prefabricated concrete decks of the cable-stayed bridges are transported from the ground via the approach bridges and main bridge side spans to Midspan. The truck crane also moves from the ground through the approach bridge and the side span of the main bridge to the front end of the completed combined beam in the mid-span, and lifts the components on the girder truck for cantilever construction. The bridge is hung with stay cables and tensioned for the first time. Construct the wet joints of the bridge deck, form the mid-span combined beam of this section, and repeat the construction until the main structure of the cable-stayed bridge is completed, and the bridge deck and the auxiliary structure of the main tower are constructed. The invention adopts the automobile crane, which can adapt to the construction of the wide bridge, and is convenient and flexible in use, and saves labor;

The invention discloses a steel box girder erection method which is applied to a steel and concrete hybrid girder cable-stayed bridge. Side-span concrete girders are constructed first, and middle-span steel box girders are installed in a segmented mode. The segments of the steel box girders are lifted to a girder transport cart on the constructed side-span girder face through a bridge tail girder lifting gantry, the steel box girders are transported into a cantilever bridge girder erection machine along rails on the girder face through the cart, and then the steel box girders are hoisted, transferred forward, turned, transferred backward and installed through the cantilever bridge girder erection machine. The constructed side-span concrete girders serve as the middle-span steel box girder transportation channel for transporting girders on girders, the steel box girder lifting, transporting and erecting process is not limited by ground construction, and navigation is not affected; the problems of construction environment constraints are solved, and multiple construction devices involved in steel box girder erection are innovatively designed, developed and successfully applied. According to on-site practice, all links are compact and controllable in terms of construction time, the steel box girder erection method is safe, reliable and high in applicability, the defects of a traditional construction method are compensated for, and development of the steel box girder erection construction technology is promoted.

The invention provides a cable-stayed bridge cable, which comprises a driving module 1, a driven module 2, a detection module 3 and a power-off protection module 4, wherein the driving module 1 takes a driving frame 5 as a mounting platform; the driven module 2 takes a driven frame 27 as a mounting platform; the detection module 3 takes a camera support frame 53 as a mounting platform; the power-off protection module 4 takes a mounting frame 56 as a mounting carrier; the driving frame 5 is connected with the driven frame 27 through connecting yokes 44 and connecting bars 45; the detection module 3 is connected with the driving frame 5 and the driven frame 27 respectively through the camera support frame 53; the power-off protection module 4 is connected with the driving frame 5 through the mounting frame 56. When an electromagnetic clutch is cut off, an electromagnet works to drive a brake band to enclasp a brake wheel, so that the robot is prevented from slipping off; and a clamping way is simple and practicable.

The invention relates to a construction method of a cable stayed bridge, which comprises the following steps of: firstly constructing the non-cable hanging section structure of a main tower column and simultaneously constructing the block-by-block structure of a main beam, simultaneously constructing the cable hanging section structure of the main tower column and the main beam, that is, constructing the cable hanging section structure of the main tower column along a vertical direction to be heightened in segments and simultaneously constructing the main beam block-by-block correspondingly towards both sides, and executing the one-by-one hanging and the tensioning of the stayed cables till the main tower column is completed and the main beam is folded. Due to the segmented construction of the main tower column, the construction of the hanging cable and the main beam is executed after a certain quantity of segments of the main tower column are completed and the construction conditions for hanging the stayed cable are met, and simultaneously, the main tower column is also continuously constructed in segments upwards so as to achieve the simultaneous construction of the main tower column and the main beam, therefore, the tower column and the beam are simultaneously constructed so as to effectively shorten the construction period and ensure the safety of the tower column structure during the construction.

The invention belongs to the technical field of steel truss girder cable-stayed bridge construction in bridge engineering, in particular relating to a quick construction method of a two-tower five-span steel truss girder cable-stayed bridge. By utilizing the quick construction method, the problems that the construction is slow and the final closure mostly influences the closure precision and line shape of the cable-stayed bridge when the symmetric cantilever method is adopting during the construction of the existing two-tower five-span steel truss girder cable-stayed bridge. The quick construction method of the two-tower five-span steel truss girder cable-stayed bridge comprises the following steps: firstly, simultaneously constructing two main tower columns by the same method, constructing the main tower columns through segmented casting, and simultaneously constructing the steel truss girder in the manner of assembling a single cantilever from side-spanning to mid-spanning through auxiliary spanning; then, carrying out the mid-spanning closure of the two main tower columns; and finally, finishing the bridge deck facility. The construction method ensures quick construction speed and is suitable for constructions of all two-tower five-span steel truss girder cable-stayed bridges.

The invention relates to a cable-stayed suspended combined supporting system based on intelligent monitoring. The cable-stayed suspended combined supporting system mainly comprises a cantilever beam, connecting beams, cantilever corner beams, right-angle connectors, large corner connectors, U-shaped bolts, a detachable positioning pile, a detachable foot baffle, a triangular support, steel wire ropes, a steel pipe supporting frame, embedded bolt sleeves and a bottom layer protecting board. The fixed end of the cantilever beam is anchored on the n floor through the U-shaped bolts and provided with the steel pipe supporting frame. The triangular support is arranged on the lower portion of the suspended end of the cantilever beam, and the cable-stayed steel wire ropes are arranged on the upper portion of the cantilever beam. The detachable foot baffle and detachable pull rings are arranged on the connecting beams. The connecting beams and the cantilever beam are connected and fixed together through the right-angle connectors. The cantilever corner beam and the connecting beams are connected and fixed together through the large-angle connectors. The structure is convenient to dismount and mount, and the profile steel space is unloaded through a reinforced unloading device composed of the cable-stayed steel wire ropes and turn buckles, so that the deformation value of the supporting system is predictable and controllable, and the cable-stayed suspended combined supporting system has good economic and technical benefits.

A movable bridge structure detection and maintenance device of the invention belongs to the bridge detection, maintenance and construction equipment, which comprises two counterbalance cars (6) each of which is hinged with at least three cantilever racks (7) in one side relative to the bridge surface and an examining and repair bench (5) with a length relative to the width of the bridge surface, wherein both sides of the width direction of the examining and repair bench (5) end are respectively provided with two suspension points (10), a suspension rope (8) is arranged on the suspension arm of the suspension rack (7) and is connected to the suspension point (10) on one end of the examining and repair bench (5). The examining and repair bench (5) is a rectangle truss and provides spacious working surface of the bridge detection and construction with rapid and easy detection and construction, short assistant time, high work efficiency and good safety, solves the avoidance problem when the bridge counterbalance cars encounter bridge side lamp rods (3) or cables, and can be used for bridges with surface of any widths, in particular for the cable-stayed bridge which cannot use prior special bridge detection cars.

The invention relates to a single tower cable-stayed bridge model test system based on damage identification for the field of bridge test science. The test system comprises a single tower cable-stayed bridge model, a lever loading system and a cable tension test system, wherein the single tower cable-stayed bridge model comprises a main bridge, a main tower, a stayed cable, a support, a base and a support upright which are assembled together; the lever loading system comprises a gantry device, a lever device and a lintel device, wherein the gantry is transversely arranged above the main beam of the single tower cable-stayed bridge model, and the lintel device is placed on the main beam of the single tower cable-stayed bridge model; and the cable tension test system comprises an anchoring screw, a leveling block, a pressure ring sensor and an adjusting nut which are mounted in a cable beam anchoring area. According to the invention, model tests for the dynamic and static performance ofthe cable-stayed bridge and experimental studies on the damage identification method of the cable-stayed bridge structure can be performed; and moreover, real-time and quick measurement of the cable tension can be realized without changing the cable rigidity, and thus the problem of difficult measurement of cable tension in the cable-stayed bridge model is solved.

A cable-stay cradle system (“cradle system”) for cable stayed bridges is mounted onto a cable stay, the opposite ends of which are attached to anchors on a bridge deck. The cradle system is disposed along the length of the cable stay and located in a pre-formed opening in a pylon. The cradle system includes axially spaced sleeve centering plates that have radially spaced holes through which the cable strands of the cable stay are threaded. The cradle system ensures that a distance from center-points of adjacent cable strands remains essentially constant along the entire length of the cradle system. The invention also provides a method of installing a cable stay including a cradle system, which includes the steps of threading the cable stay through the opening in the pylon so as to locate the cradle system in the opening, and attaching the cable stay to anchors on the bridge deck.

The invention relates to a cable-climbing robot used for detecting poly ethylene (PE) damage on the surfaces of cables in a suspension bridge and a cable-stayed bridge, wherein the cable-climbing robot comprises a driving trolley (1) and a driven trolley (2) which are arranged symmetrically on the left and right sides; both the driving trolley (1) and the driven trolley (2) are provided with two wheels (7) and connected with each other through a connecting piece; a four-connecting-rod tensioning mechanism (9) is arranged on the driven trolley (2) and comprises four connecting rods (13), an adjusting screw rod (14), an adjusting nut and an adjusting spring (12); a climbing mechanism is arranged on the driving trolley (1) and comprises one pair of helical gears with matched right angles, a direct current motor (5) and a transmission chain (6); And V-shaped grooves are arranged on the wheels (7) of the driving trolley (1) and the driven trolley (2). The cable-climbing robot is applied to the surfaces of various cables used at present and is suitable for operation condition in high air; the commonality is good; rechargeable batteries are adopted for providing power; and the cable-climbing robot has simple structure design, and is convenient in maintenance and safe and reliable in operation.

The invention discloses a multifunctional comprehensive restraint device for whole construction and operation process of a long-span hybrid-beam cable-stayed bridge and relates to a bridge engineering technique. The multifunctional comprehensive restraint device comprises longitudinal dampers, multidirectional slideable supports and retractable devices. Longitudinal damping devices, longitudinal comprehensive multifunctional devices and transverse windproof supports with independent functions are arranged between a main beam and bridge towers. A damping function is independently realized at the operation period of the bridge. The longitudinal comprehensive multifunctional devices realize solidifying, pushing and limiting functions in the whole construction and operation process of the bridge. The multifunctional comprehensive restraint device provides effective rigidity and damping for the operation period of the long-span hybrid-beam cable-stayed bridge and guarantees that the static and dynamic response of the bridge is within an acceptable range. At the same time, the longitudinal comprehensive multifunctional devices are used for taking a temporary solidifying function in the splicing process of the upper structural cantilever of the bridge and are also used as main beam pushing force-bearing structures under the condition of full-bridge closure, a no-stress geometrical linear bridge construction control method is realized, the functions are clear, the force is born reasonably, the economic and practical performance is high and the multifunctional comprehensive restraint device is suitable for all kinds of long-span hybrid-beam cable-stayed bridges.

The invention relates to a determination method based on an ANSYS second development platform of the initial completion initial cable force of a cable-stayed bridge. The method uses the design cable force as the target value, considers the geometric non-linear effect and performs iteration for solving and correcting the cable initial strain under the action of dead load. The method comprises the following specific steps: any group of cable forces is assumed to be added on the stay cable in the mode of initial strain, dead load is added to calculate, the *do-loop command language is used to extract the calculated cable force of the stay cable and check whether the error between the cable force and the target completion cable force is within an available limit; if the error is large, the indifference method is used to correct the stay cable initial strain, then the error is calculated again until the error is within the available limit; and the initial completion initial cable force can be obtained by multiplying the last calculated group of stay cable initial strains by the elastic modulus of the stay cable which is corrected by considering the vertical effect. By using the method, the solving time of the completion initial cable force of the cable-stayed bridge can be reduced and the precision can be increased, thus the method has large practical engineering application value.

The invention discloses a hydraulic climbing formwork construction method for a leaning tower of a cable-stayed bridge. The method comprises the following steps: measuring and positioning the leaning tower and embedding an embedded part; erecting a formwork and pouring a first section of concrete, and mounting an anchoring system, a bearing bolt (1) and a climbing frame (3); mounting a bearing frame and a bearing platform on the anchoring system; mounting a template moving frame and an upper platform system, using the upper platform system for erecting the formwork, embedding the embedded part and pouring a second section of concrete of a tower column; mounting a lower platform and de-molding by moving the upper platform system; mounting the anchoring system in a third stage and mounting a climbing guide rail (5) and a guide rail supporting leg (6); operating a hydraulic system, lifting the whole frame to the third stage of the tower column, and mounting a lower-layer platform; assembling the mould by moving the upper platform system, embedding the embedded part and pouring a fourth section of concrete of the tower column; and operating the hydraulic system, lifting the whole frame to the fourth stage of the tower column, and entering into a circulating construction stage. According to the method provided by the invention, the mounting of the template is quickly and efficiently finished under the condition of the leaning tower column and the work load of mounting the template and the bracket is saved.

The invention belongs to the technical field of bridges, and discloses a method for identifying damage on inhaul cables of long-span cable-stayed bridges. The method includes building finite element models of cable-stayed bridges; applying simulated wind load to the finite element models and acquiring wind speed time-history curves of the inhaul cables; computing stress time histories of the inhaul cables under wind load effect on the basis of the wind speed time-history curves; carrying out lifting wavelet packet decomposition on the stress time histories and stress time histories of bridge inhaul cables in non-damage states, extracting wavelet packet signal component energy and utilizing energy accumulation variation values as characteristic values for identifying damage positions of thestay cables; acquiring lifting wavelet packet component energy difference, building BP-AdaBoost models for identifying structural damage degrees and computing the fatigue reliability of the inhaul cables on the basis of the structural damage degrees. The method for identifying the damage on the inhaul cables of the long-span cable-stayed bridges has the advantages of excellent adaptability and identification reliability.

The invention discloses a mid-span closure method for a steel box girder of a cable stayed bridge. The method is implemented twice by using splicing of the steel box girder at the closure section and mounted cantilever steel box girder sections at the two ends of a closure opening, and comprises the steps of: during first splicing, mounting a closure opening width longitudinal adjustment device between the first cantilever steel box girder section on one side of the closure opening and a lower cross beam of a lateral tower column, pushing the first cantilever steel box girder section by using the closure opening width longitudinal adjustment device in the same direction, and splicing the steel box girder at the closure section and the second cantilever steel box girder section on the other side of the closure opening by a splicing method for a standard girder section; and during second splicing, pushing the first cantilever steel box girder section by using the closure opening width longitudinal adjustment device in a reverse direction, fixing the relative position between the steel box girder at the closure section and the first cantilever steel box girder section by using a welding seam locking device, and performing welding seam splicing between the steel box girder at the closure section and the first cantilever steel box girder section under an unstressed condition. The method has the characteristics of simple and convenient construction.

The invention relates to a construction method for demounting a cable-stayed bridge fast. An anchor is hard to be removed under the condition that a stayed cable has cable tension, a special tool is used for transforming the stress of an upper anchor ring, a cable and a lower anchor head into zero, then an upper anchor head is cut by compulsion, the cable is chopped up, and the lower anchor head is removed for saving the anchor-removing time, so as to change cables fast. A punching tensioning jack is installed at an anchor pipe opening of the cable. A tension rod is arranged in the jack. The tension rod tensions after penetrating into a tool anchor ring. The tool anchor ring is screwed into the tail end of an anchor head to replace an old anchor ring, and the old anchor ring is taken out by cool cutting. The jack is moved to the tail of the tension rod by the repeated tension and release of the tool anchor ring to ensure that the cable still has 30 to 40 tons of tension. Two sets of cable clamps are used for clamping two ends of the cable to be chopped up. A windlass pulley set is connected between the cable clamps. The pulley set is frapped to transform the internal force of the cut section of the cable into zero and chops the cable. A hoisting apparatus is used for taking out the cut cable on a tower. A hollow drill rod is used for drilling concrete or epoxy mortar in a cable anchor pipe at the end of a beam. The punching tensioning jack is used for pulling out the anchor head by compulsion.