630 results about "Composite girder" patented technology

The invention relates to the technical field of hogging moment region calculation, in particular to a hogging moment region long-term rigidity prediction method for a steel-concrete composite beam bridge. The invention discloses a long-term rigidity prediction method for a hogging moment area of a steel-concrete composite beam bridge. Comprising the steps that a welding stud connecting piece degradation time-varying model and a concrete bridge deck degradation full-time-domain model under the corrosion-fatigue coupling effect are constructed according to test data, and a steel-concrete composite beam bridge hogging moment area rigidity degradation model, steel-concrete composite beam bridge hogging moment area long-term rigidity prediction and the like are constructed. In the process of predicting the rigidity of the hogging moment area of the steel-concrete composite bridge, the deterioration mechanism of a welding stud connector under the corrosion-fatigue coupling effect is considered, the pitting corrosion condition under the environment influence and the welding stud crack condition under the vehicle load influence are considered, the influence of bridge deck slab cracks is considered in the pitting corrosion condition, and the rigidity of the hogging moment area of the steel-concrete composite bridge is predicted. In addition, the mutual relation among the welding stud pitting corrosion influence, the welding stud crack influence and the bridge deck crack influence is considered, and the rigidity of the hogging moment area of the steel-concrete combined bridge is accurately analyzed.

The invention relates to the technical field of building structures, in particular to a method for calculating node shear bearing capacity of a composite beam, which comprises the following steps of: decomposing the shear bearing capacity of a node core area into shear contribution components of a square steel tube web, encased concrete and a steel wire mesh, and respectively calculating the shear bearing capacity based on respective structural characteristics and stress mechanisms; the total shear bearing capacity is obtained through superposition; and each component is quantized by introducing correction coefficients of an axial compression ratio and a beam-column linear stiffness ratio. According to the method, the technical blank of shear resistance calculation of the concrete joint in the core-free area is filled, the error is controlled within + / -15%, and the method has the characteristic of high precision, is suitable for design of the composite beam joint filled with the concrete in the core-free area in a high-rise building and an underground structure, is high in engineering applicability and provides a reliable calculation basis for design of related building structures.

A U-shaped recycled concrete composite beam, and a design and construction method therefor, the U-shaped recycled concrete composite beam comprising a prefabricated concrete casing (11) and cast-in-place compression-zone concrete (12), wherein the prefabricated concrete casing (11) is a recycled concrete casing, and has a U-shaped appearance; the cast-in-place compression-zone concrete (12) is high strength concrete, and the cast-in-place compression-zone concrete (12) is concrete with a strength grade of C50-C80; the thickness h1 of the bottom of the prefabricated concrete casing (11) is not less than 80 mm, and the widths b1 and b3 of lateral surfaces of the prefabricated concrete casing (11) are both not less than 45 mm; the width b2 of the cast-in-place compression-zone concrete (12) is not less than 100 mm; and a steel bar cage is provided in the U-shaped recycled concrete composite beam to serve as a framework. Compared with the prior art, the fire-resistant characteristic of recycled concrete and the excellent mechanical properties of high-strength concrete are fully exerted, the flexural bearing capacity and ductility of the recycled concrete beam can be effectively improved at room temperature, the bursting phenomenon of a fire-exposed surface is reduced at a high temperature, and the temperature field in the beam is significantly reduced.

The invention relates to the technical field of parameter optimization, and discloses a steel-concrete composite beam bridge prefabricated segment prestress tension parameter optimization method and system, and the method comprises the steps: obtaining a design BIM model, classifying prefabricated segments, constructing an initial digital twinborn model, and obtaining monitoring data; processing the monitoring data to obtain corrected data; comparing the corrected data with a model simulation result, and calibrating the model to generate a precise digital twinborn model; evaluating a multi-dimensional robustness index to construct a feature vector; generating a self-adaptive tensioning strategy sequence through a graph neural network in combination with the feature vector and the precise model; according to the method, intelligent optimization of the tensioning parameters is achieved, and the construction precision and the structural safety of the steel-concrete composite beam bridge are remarkably improved.

The invention relates to the technical field of structural engineering, and discloses a post-fatigue residual stiffness calculation method for an assembly type composite beam, which comprises the following steps: acquiring three-dimensional laser point cloud data and thermal infrared image data of the composite beam, and registering the three-dimensional laser point cloud data and the thermal infrared image data; quantifying the macroscopic geometric defect based on the multi-modal data; welding area features are extracted, and micro-crack forms are recognized; constructing a microcrack network diagram and extracting parameters; evaluating the influence of the microcrack network on the local rigidity by adopting a self-attention map neural network, and obtaining a rigidity parameter after multi-scale damage correction in combination with the influence of the macroscopic geometric defect; calculating residual stiffness after fatigue by combining fatigue load history; according to the method, the initial geometric defect and the early microscopic damage can be comprehensively considered, and the accuracy of the residual stiffness calculation of the fabricated composite beam is improved.

The invention relates to a calculation method and device for construction tensioning force of a hybrid-composite beam cable-stayed bridge, and the method comprises the following steps: building a full-bridge finite element model, and setting the last tensioning force as a designed finished bridge cable force; constructing a target formula including a stay cable force, a main beam tangential displacement and a main tower longitudinal deviation influence matrix; calculating a bridge forming state initial value and establishing an optimization objective function; forming an iterative loop calculation system; the cable force uniformity of stay cables on the two sides of the side midspan, the stress limit values of a main tower and a main beam and the pressure reserve of a transition pier and an auxiliary pier are controlled; and finally, the tensioning force of each time in the construction process is determined. The method emphasizes the consistency of finite element simulation and on-site construction, considers the shapes of a vertical curve and a horizontal curve of the bridge and the bending effect, and is suitable for bridges with various spans and curve forms; the method can effectively consider the concrete shrinkage and creep effect, is rapid in convergence, high in efficiency and wide in application range, meets multi-parameter constraint conditions, and ensures that a finished bridge state is closed with an ideal result.

The invention relates to the technical field of steel-concrete composite beams, and discloses a steel-concrete composite beam bridge deck reinforcing device which comprises a sealing plate, a first hydraulic cylinder, a first supporting plate, a first polished shaft, a second supporting plate, a first support, a first rotating arm and a second hydraulic cylinder. In the using process, when one side of the top face of the web beam is subjected to overload pressure, the second supporting plate on the same side can be pressed downwards, then the first supporting plate on the same side is made to move downwards, and therefore the moving ends of the first hydraulic cylinders on the same side are made to return. And at the moment, hydraulic oil in the rodless cavities of the first hydraulic cylinders on the same side can enter the rodless cavities of the second hydraulic cylinders on the same side, and then the moving ends of the second hydraulic cylinders on the same side stretch out. And then, under the support of the first support on the same side, the first rotating arms on the same side can deflect towards the direction of the web beam. Due to the fact that hydraulic pressure is adopted as a power source, enough supporting force can be provided for the bottom face and the two side faces of the web beam, and then the anti-overturning performance is improved.

The invention provides a large-span corrugated steel web composite beam and a construction method thereof. The composite beam adopts section prefabrication and field assembly, and a composite abutted seam system is creatively adopted between beam sections. Butt welding is adopted for corrugated steel webs between beam sections, glue seams are adopted for concrete, and shear key teeth are matched, so that the self-alignment performance and the interface shear bearing capacity of a matching surface are improved; wave-shaped abutted seam notches are formed in the upper portions of the concrete top plate and the concrete bottom plate, concrete above abutted seams is a continuous pouring body, the waterproof performance is durable and reliable, and the long-term safety and the service life of the structure are effectively guaranteed under the condition that a waterproof leveling layer is not arranged. And in addition, the concrete in the notches is pre-pressed through the tensioning external prestressing procedure after the beam bodies are closed, the concrete at the abutted seams is further compacted, and super-strong durability is provided. A concrete waterproof layer does not need to be independently arranged on the main beam structure, the second-phase dead load borne by the main beam is effectively reduced while the work amount is reduced, and economic benefits are remarkable.

The invention provides a counterweight difference adjustment method for hogging moment area jacking of a special-shaped multi-girder steel-concrete composite beam, which comprises the following steps of: establishing a finite element model of the special-shaped multi-girder steel-concrete composite beam, and arranging two ends and the middle part of the special-shaped multi-girder steel-concrete composite beam on a beam column; performing jacking height simulation of different numerical values on the special-shaped multi-girder steel-concrete composite beam at the middle supporting point for many times to obtain a first bridge deck stress result at the middle supporting point; carrying out balance weight difference adjustment finite element simulation on the basis of the first bridge deck stress result, and applying a balance weight along the line type of the main beam to adjust the pre-compressive stress of the bridge deck at the middle fulcrum of the main beam so as to achieve a design target; and the concrete bridge deck is constructed on the basis of counterweight data obtained through counterweight difference adjustment finite element simulation. By establishing a finite element model and carrying out multi-group jacking height simulation and subsequent counterweight difference adjustment simulation, the stress state of the bridge deck at the middle fulcrum of each main beam under different working conditions can be accurately determined. The counter weight is applied on the basis, so that the stress nonuniformity caused by a special-shaped structure and a multi-girder system can be effectively made up, the pre-compressive stress of the bridge deck at the middle supporting point of each girder is more uniform, and the design goal is accurately achieved.

To provide a method for removing a floor slab of a composite girder capable of reducing concrete remaining on the girder.SOLUTION: Since a cutting-in 5 extending in the bridge-axis direction is formed from the upper surface side of a floor slab at each arrangement location of a slippage preventing member 4 of a floor slab 3, and the floor slab 3 on which the cutting-in 5 is formed is pulled upward from main girders 2 and removed, the resistance force between the slippage preventing member 4 and the concrete of the floor slab 3 against the tensile load can be reduced by the cutting-in 5, and the floor slab 3 can be easily separated from the main girders 2. Thus, since it is not necessary to cut the floor slab 3 in the bridge axial direction such that concrete remains on the main girder 2 as in the related art, the floor slab 3 on the main girder 2 can be lifted and removed at once without being divided in the direction perpendicular to the bridge axis. As a result, the efficiency of the removal work can be improved, and there is an advantage that a large-scale concrete crushing work is not required.SELECTED DRAWING: Figure 5

A method for rapidly calculating the interface slip of a steel-concrete composite beam under vehicle dynamic loads relates to the technical field of bridge construction. The method comprises the following steps: calculating the first n natural frequencies of a simply supported steel-concrete composite beam based on basic bridge parameters; calculating the circular frequency of vehicle dynamic loads; calculating the bridge's natural frequencies and critical damping frequencies taking into account the influence of damping; calculating the introduction parameters; calculating the interface slip under vehicle dynamic loads taking into account the first n vibration modes; determining convergence; and calculating the interface slip under multiple vehicle dynamic loads. Based on the Timoshenko beam theoretical model, and taking into account the material, cross-section, and connector stiffness, a formula for calculating the interface slip of a simply supported steel-concrete composite beam under vehicle dynamic loads is proposed. This formula enables rapid and accurate calculation of interface slip without relying on numerical simulation or field testing.

The utility model provides an inter-beam connecting structure for a steel and concrete composite beam, which comprises a composite beam, the composite beam comprises a bridge deck slab and a composite rib plate positioned on the bottom surface of the bridge deck slab, the butt joint end of the bridge deck slab is provided with a first bridge deck post-pouring area, and the butt joint end face of the bridge deck slab is provided with a connecting plate II in the range of the first bridge deck post-pouring area; the second connecting plates of every two adjacent composite beams are connected through second bolt assemblies, and after connection is completed, UHPC concrete is poured into the first bridge floor post-pouring area; the combined rib plates of every two adjacent combined beams are connected in a rigid connection mode. The two second connecting plates are connected through bolts, concrete is poured into the first bridge deck post-pouring area after bolt connection, the connecting integrity between the bridge deck slabs is good, and meanwhile the situation that heat is generated by welding between the second connecting plates, and connection between the second connecting plates and the bridge deck slabs is affected is avoided.

The utility model relates to the technical field of bridge expansion and reconstruction, and discloses a bridge widening corrugated plate splicing structure which comprises a corrugated plate, the corrugated plate connects an old bridge with a steel-concrete composite beam through a connecting piece, the corrugated plate is located between the old bridge and the steel-concrete composite beam, the upper portion of the corrugated plate is filled with asphalt concrete, and the lower portion of the corrugated plate is filled with concrete. The top face of the asphalt concrete is flush with the top face of the old bridge and the top face of the steel-concrete composite beam. The corrugated plate is spliced between the old bridge and the steel-concrete composite beam, the upper portion of the corrugated plate is filled with the asphalt concrete so that the plane of the corrugated plate can be flush with the old bridge and the steel-concrete composite beam, the asphalt concrete and the corrugated plate bear additional internal force generated by the settlement difference of the new bridge and the old bridge together, and the crack resistance of the connecting structure at the splicing position can be effectively improved.

The invention relates to the technical field of building construction, in particular to an auxiliary scaffold for building a concrete filled steel tubular column and a composite beam, which comprises a support body consisting of a bearing screw rod inserted into the ground, a vertical rod mounted at the top end of the bearing screw rod in a threaded manner, a disc buckle fixed on the outer surface of the vertical rod and a bottom horizontal tube mounted on the disc buckle in a clamping manner, the number of the frame bodies is multiple, the multiple frame bodies are distributed at equal intervals and connected to form the scaffold, and leveling plates are arranged outside the bearing screws. A connecting mechanism is arranged above the leveling plate, the connecting mechanism comprises a base, a bearing seat and a locking piece which are sequentially distributed from bottom to top, and a horizontal connecting plate is hinged to the outer portion of the base. According to the auxiliary scaffold for building the concrete filled steel tubular column and the composite beam, the rotating locking piece moves downwards along with the bearing screw rod, the functions of unfolding the working platform and holding and locking the bearing screw rod can be synchronously completed, multiple construction steps are combined, and the building efficiency is greatly improved.

The invention discloses a steel-concrete composite beam structure assembled by hot-rolled section steel and a construction method of the steel-concrete composite beam structure. The composite beam structure comprises two pieces of H-shaped section steel; channel steel; two pieces of angle steel with opposite openings are arranged on the upper flange plates on the two sides of the channel steel; two folding flanges are arranged on the top face of the steel tank, and the transverse inner side faces of the folding flanges are connected to a lower flange plate of one piece of H-shaped steel; the bottom end of the long bolt rod is provided with a nut and embedded into concrete poured in the steel groove, the top end of the long bolt rod is upwards fastened, the upper flange plate and the transverse plate of the angle steel are connected in an overlapped mode, and the top end of the long bolt rod is provided with a nut and embedded into concrete poured in a groove cavity formed between the angle steel. According to the steel-concrete composite beam structure and the construction method thereof, the steel-concrete composite beam can be formed by directly assembling the hot-rolled section steel products on site, the steel structure machining and manufacturing links are avoided, welding, formwork installation and steel bar binding operation are not needed, the technological process is greatly shortened, independent replacement of a single component can be achieved in the operation period, and economic benefits are remarkable.

The invention discloses a composite beam capable of enhancing the ultimate strength of an ultimate concrete structure. The span of the beam is measured, a bending moment graph of the beam is drawn, according to analysis of the bending moment graph, UHPC is selected for a pure bending section (the middle of the span) above a neutral axis of the beam, the upper half part of the beam is covered, and common concrete is used for the rest parts; half of the beam height is selected to use UHPC on the upper portion, and the structural ultimate strength of the composite beam can be improved; the FRP rib is used on the lower portion of the beam, the tensile property and ductility of the lower portion can be improved, a sleeve grouting anchorage device (the inner wall of a metal sleeve is provided with threads) and a wedge-shaped anchorage device (the clamping section is wrapped with a copper sleeve) are adopted, the anchoring reliability is ensured through the double effects of chemical bonding and mechanical meshing, and due to the fact that the FRP rib can be subjected to brittle failure and is preset to be in a super rib failure mode, the tensile strength and ductility of the lower portion can be improved. The problem of brittle failure of the FRP rib is solved. The beam is simple in design, convenient to construct, reasonable in stress, high in structural ultimate strength, high in reliability, wide in application range and material-saving.

The invention discloses a steel-concrete laminated slab composite beam structure and an assembly method, the structure comprises a steel plate shear connector, the left side and the right side of the steel plate shear connector are symmetrically provided with a group of concrete prefabricated bottom plates respectively, and a concrete post-pouring layer is arranged above the concrete prefabricated bottom plates; a plurality of clamping grooves are formed in the upper end of the steel plate shear connector, transverse additional steel bars are clamped in the clamping grooves, and the transverse additional steel bars extend to the left side and the right side to the position below the concrete post-pouring layer; each concrete prefabricated bottom plate comprises a middle plate and end plates located at the front end and the rear end of the middle plate, the upper surface of each middle plate and the upper surface of each end plate are each provided with a plurality of dovetail grooves in the front-back direction, and a plurality of seam splicing steel bars are jointly connected into the coaxial dovetail grooves in a clamped mode. The structure solves the problem that a traditional steel-concrete composite beam anti-shear connecting piece is limited in anti-shear performance; the prefabricated bottom plate is low in production efficiency and difficult to hoist and transport; during construction of plate end and plate side connecting structures, horizontal reinforcing steel bars conflict, and transverse additional reinforcing steel bars and abutted seam reinforcing steel bars are difficult to position.

The invention belongs to the field of deep foundation pit intelligent supporting systems, and particularly relates to a deep foundation pit intelligent supporting system based on oblique beam grid and digital twinning and a collaborative construction method.The deep foundation pit intelligent supporting system based on oblique beam grid and digital twinning comprises an oblique beam grid supporting structure composed of two-way crossed steel oblique beams, and the outer layer of each steel oblique beam is a Q355B steel pipe with the thickness not smaller than 12 mm; the inclined beam is filled with ultra-high performance concrete with the compressive strength not smaller than 150 MPa, the inclination angle of the inclined beam ranges from 25 degrees to 60 degrees, and an MEMS micro-electro-mechanical system sensor is pre-buried at a node; and the digital twin platform integrates the geological BIM model and the LSTM neural network prediction model. The bending rigidity is improved through the oblique beam grid supporting structure and the concrete filled steel tube composite beam, the inclination angle ranges from 25 degrees to 60 degrees, force flow transmission is optimized, and micro-strain-level stress monitoring is achieved through the MEMS sensors embedded in the nodes. A digital twin platform and an LSTM model are fused with 12-dimensional parameters, the 72-hour deformation prediction error is smaller than or equal to 1.5 mm, and compared with a traditional experience algorithm, the precision is improved.

The invention discloses a method for calculating the natural vibration frequency of a steel-concrete composite beam under common boundary conditions, and relates to the technical field of high-speed railway bridge construction. The method comprises the steps that material parameters and the cross sectional area of the steel-concrete composite beam are obtained; calculating a dimensionless coefficient according to material parameters and section parameters of the steel-concrete composite beam; according to the dimensionless coefficient, the first frequency reduction coefficient, the bending resistance combination connection coefficient, the second frequency reduction coefficient and the third frequency reduction coefficient; and calculating the natural vibration frequency of the single-span steel-concrete composite beam under the common boundary condition according to the three frequency reduction coefficient calculation expressions. According to the method, the shear deformation influence is considered, the frequency approximate value of the single-span steel-concrete composite beam under any boundary condition can be calculated, the calculation precision is high, and the method is also suitable for other partially-interacted composite beams formed by connecting two different materials through flexible shear connectors.

The invention relates to the technical field of bridge engineering, in particular to a linear control method for asynchronous construction of a PK section composite beam cable-stayed bridge, which is characterized in that in the manufacturing process, through pre-assembly and batch manufacturing, the manufacturing precision is accurately controlled, and the linear accuracy of a PK section composite beam section during manufacturing is ensured; in the transportation process, the manufacturing of the PK section composite beam section is reinforced, and the PK section composite beam section is prevented from being deformed by the supporting pad; in the hoisting process, it is ensured that the transverse line shape of the PK section composite beam section to be hoisted and the transverse line shape of the hoisted PK section composite beam section are consistent in a reverse jacking mode; in the subsequent construction process, the hoisting elevation positioning point is continuously measured, and even if the hoisting elevation positioning point deviates due to the rigidity change of the bridge, the longitudinal line shape can be adjusted by tensioning the stay cable.

The invention discloses a steel plate composite beam cable-stayed bridge tower beam consolidation connection structure which comprises a pressure-bearing steel plate, a concrete cushion block, a first connecting piece and a second connecting piece, the pressure-bearing steel plate is welded to the end of a steel main beam and is consolidated with the concrete cushion block through the first connecting piece, and the concrete cushion block and a concrete bridge tower are synchronously poured together. The concrete bridge deck slab is connected with the concrete bridge tower into a whole in a post-pouring mode, and the pressure-bearing steel plate and the concrete bridge tower are tightly connected together through the second connecting piece. The method has the advantages that the end pressure-bearing steel plates are adopted, axial force and bending moment are transmitted to the concrete bridge tower through the pressure-bearing steel plates, shearing force and torque are transmitted to the concrete bridge tower through connecting pieces of the pressure-bearing steel plates and friction force between the steel plates and the bridge tower, and the structural force transmission path is clear and simple; the pressure-bearing steel plates are provided with welding studs connected with the concrete cushion blocks, and conflict between the welding studs and concrete bridge tower main reinforcements is avoided; 3, the pressure-bearing steel plates are tightly connected with the concrete bridge tower through the opposite-pulling steel beams, so that insufficient shear capacity caused by small axial force of a main beam during construction is avoided, and meanwhile, the safety reserve of the structure during operation can be improved; the structure is simple, force transmission is reliable, and construction is simple.

The invention relates to an efficient assembly type steel-concrete composite beam bridge superstructure connecting structure and a construction method, and belongs to the technical field of bridge engineering. Comprising a prefabricated concrete bridge deck, a steel beam, an umbrella-shaped perforated steel pipe connecting piece, a high-strength hook, a wedge-shaped steel accessory, a pi-shaped metal part, an H-shaped high-strength steel accessory, a high-strength bolt and a nut. The wedge-shaped steel accessory is pre-buried in the transverse joint direction of the prefabricated concrete bridge deck slab through a pi-shaped metal part, the bridge deck slab in the transverse joint direction is fastened through an H-shaped high-strength steel accessory, and the H-shaped high-strength steel accessory and the wedge-shaped steel accessory are fastened through a high-strength bolt and a nut; the umbrella-shaped perforated steel pipe connecting pieces are welded to the steel beams, the high-strength hooks are pre-buried in the prefabricated concrete bridge deck in the longitudinal joint direction, the high-strength hooks and the umbrella-shaped perforated steel pipe connecting pieces are hooked tightly after the bridge deck is in place, longitudinal steel bars penetrate through the holes, in the bridge direction, of the umbrella-shaped perforated steel pipe connecting pieces, and finally high-performance grouting materials are poured in the longitudinal joints.

The invention discloses a composite beam plastic flexural capacity correction calculation method considering interface slippage. The method is suitable for a hogging moment area of a steel-concrete composite beam reinforced by an external prestress carbon fiber reinforced composite material rib. The method comprises the following steps: firstly, determining basic static boundary parameters and a shear connector constitutive model; in the iterative calculation, solving a temporary bearing capacity by utilizing an axial force and moment balance equation, and calculating interface slippage along the beam length and a deformation loss item at the support based on internal force distribution; then determining a rigidity degradation coefficient according to the average slip amount, and dynamically reducing the static yield bending moment to reconstruct the plastic hinge length; and finally, constructing a corrected deformation coordination equation, deducting a deformation loss item in geometric deformation calculation to obtain the real elongation of the in-vitro CFRP rib, and updating a stress parameter until a result is converged. According to the method, by introducing a deformation loss item and a rigidity degradation mechanism, deviation caused by traditional rigid connection assumption is corrected, and accurate prediction of the ultimate bearing capacity is achieved.

The invention relates to the technical field of bridge deck monitoring, and particularly discloses a wet joint monitoring system for a prefabricated bridge deck, a composite beam prefabricated member comprises a bottom shear nail, a top shear nail, a PBL perforated plate and a vertical trapezoidal key tooth wet joint, and the surface of the composite beam prefabricated member is brushed with white interior wall paint before a test is started; positioning grids are formed by using ink lines to serve as monitoring points, stress data and displacement data of the monitoring points on the surface of the composite beam prefabricated part are obtained and used for obtaining stress data and displacement data of the monitoring points on the surface after a load is applied, a change curve is drawn, damage variables are constructed according to the change curve, and recognition and early warning are conducted according to the damage variables. According to the method, high-precision and generalizable stress-deformation data can be obtained, and a solid foundation is laid for subsequent numerical simulation, health monitoring and remote maintenance.

The invention provides a steel-concrete composite beam hogging moment region rigidity degradation rule calculation method and a storage medium, and belongs to the technical field of computer-aided calculation. The method comprises the following steps of S100, determining random fatigue loads borne by a hogging moment area of the steel-concrete composite beam, and calculating the amplitude S and the amplitude distribution rule of each fatigue load; s200, performing curve fitting on the amplitude distribution rule of the fatigue load, and determining a probability density function of the amplitude of the fatigue load; s300, determining the fatigue life of the hogging moment area of the steel-concrete composite beam; s400, the static load ultimate bearing bending moment of the hogging moment area of the steel-concrete composite beam is determined; s500, determining a rigidity reduction value of the hogging moment area of the steel-concrete composite beam during fatigue failure; and S600, calculating the rigidity degradation rule of the steel-concrete composite beam under the random fatigue load. According to the method, the rigidity degradation process of the hogging moment area of the steel-concrete composite beam can be calculated and predicted in advance, and a theoretical basis is provided for maintenance and repair of a bridge.

The invention relates to the technical field of simulation calculation, in particular to a simulation calculation method of a U-shaped steel-encased-concrete composite beam, which comprises the following steps: S1, establishing a two-parameter interface equivalent stiffness model of the U-shaped steel-encased-concrete composite beam with a rear anchor bolt; s2, solution and response extraction; s3, calculating a slip residual error and interface energy, and judging whether a target slip feature is met or not according to a double-convergence criterion; if the convergence requirement is not met, adaptively updating the interface parameters and returning to S2 for repeated solution, and if the convergence criterion is met, applying the converged interface rigidity parameters to design feedback of pretightening force selection of the rear anchor bolts and anchor bolt spacing and node construction of the rear anchor bolts. According to the method, the two-parameter interface equivalent stiffness model and the adaptive algorithm based on the slip residual error enable the interface normal stiffness and the interface tangential stiffness to be automatically converged to the target slip characteristic, manual parameter adjustment is avoided, the simulation stability and the calculation precision are improved, and integration of composite beam structure design and simulation analysis is achieved.

The utility model discloses an assembly type UHPC narrow steel box girder composite beam which is structurally characterized in that a plurality of prefabricated UHPC bridge deck slabs are connected side by side through transverse joints, the bottoms of the prefabricated UHPC bridge deck slabs connected side by side are connected to a plurality of narrow steel box girders through box type shear connectors, and the narrow steel box girders are connected through a plurality of transverse connectors. The prefabricated UHPC bridge deck slab has the advantages that the prefabricated assembly degree is high, the number of wet joints is small, the supports extend out of the joints of the prefabricated UHPC bridge deck slab, no formwork is needed during construction, the construction period is shortened, and the construction efficiency is improved; the box-type shear connector is pre-buried in the UHPC bridge deck slab in the prefabrication stage of the UHPC bridge deck slab, so that the integrity of the shear connector and the bridge deck slab is improved, the problem of conflict between bridge deck slab reinforcing steel bars and shear keys on a construction site is solved, meanwhile, the steel-concrete composite beam construction steps are reduced, and the construction efficiency is improved.

The invention discloses a construction method and device for intelligently adjusting prestress of a steel-concrete composite beam bridge deck slab. The construction method comprises the following steps: assembling and calibrating the bridge girder erection machine, installing the strain sensor and hoisting the steel beam, connecting the lifting and control device, applying a pre-lifting force to the steel beam, dynamically adjusting the lifting force by the central control system according to data of the sensor in the whole process of installing the bridge deck slab, and locking the lifting force to construct cast-in-place concrete after the bridge deck slab is installed. And after the strength is reached, releasing the lifting force to generate preset pressure stress, and the like. The device comprises a bridge erecting machine, a plurality of lifting and control devices, a monitoring system and a central control system. The lifting force is dynamically adjusted through multi-sensor cooperative monitoring and the central control system, the stress of the steel beam and the bridge deck can be effectively balanced, the construction efficiency is improved, the construction quality is guaranteed, the bridge structural performance is enhanced, the generation of cracks of the bridge deck is reduced, and the method is suitable for construction of various steel-concrete composite beam bridges.

The invention discloses a method and system for analyzing the mechanical property of a hogging moment area of a UHPC thin-layer reinforced steel-concrete composite beam, and belongs to the technical field of composite beam performance analysis data processing. The method comprises the following steps: obtaining a geometric mechanical property reduction model of the non-uniform rusted steel bar according to a steel constitutive model and mechanical property test data of the rusted steel bar; according to the UHPC constitutive model, comparing the ultimate load with the unloaded proportion and the ultimate load with the preloaded proportion under the same chlorine salt corrosion damage degree to obtain a concrete damage coefficient; a residual flexural capacity model of the UHPC reinforced steel-concrete composite beam after the load-corrosion effect is obtained according to a geometric mechanical property reduction model of the non-uniform corrosion steel bar and a composite beam force balance equation, and a long-term bending calculation model of the UHPC reinforced steel-concrete composite beam after the load-corrosion effect is obtained by introducing a correction coefficient; and the bearing capacity performance analysis accuracy of the steel-UHPC composite beam in the hogging moment area under the load-corrosion coupling action is improved.

The invention relates to the technical field of crack resistance detection, in particular to a road steel-concrete composite beam bridge deck pavement crack resistance detection method and system which comprises a support, a test piece, a plurality of loading units and a bottom supporting and adjusting assembly. The bottom supporting and adjusting assembly comprises two bottom side edge supporting pieces, a bottom center supporting piece, two moving blocks and a plurality of connecting rods, the bottom side edge supporting pieces are driven to move through the moving blocks, the bottom center supporting piece is driven to move upwards and abut against and support the lower portion of the test piece through the action of the connecting rods, and meanwhile the bottom side edge supporting pieces on the two sides move downwards; then, only the lower central area of the test piece is supported, and at the moment, the two sides of the test piece can be subjected to a loading test through the upper loading unit; therefore, loading tests on the center and the two sides of the test piece can be carried out, rapid adjustment can be carried out in a linkage mode during switching, test data can be enriched, the test efficiency can be guaranteed, and crack resistance detection is more comprehensive.