838 results about "Composite girder" patented technology

The invention provides a corrugated steel web composite beam performance detection device and method, and belongs to the technical field of composite beam performance detection.The corrugated steel web composite beam performance detection device comprises a base, a composite beam, a counter-force device and two placing frames installed on the base; the counter-force device comprises a plurality of mounting beams which are arranged at equal intervals and cross beams which are mounted on the inner sides of the mounting beams, and further comprises a moving mechanism, an adjusting mechanism and a detecting mechanism, and when the performance of the composite beam is detected, a first driving motor and a second driving motor on the same side are controlled by a controller to rotate, so that the performance of the composite beam is detected; the loading devices and the fixing pieces on the same side move synchronously, the two-way driving state of a vehicle in the actual situation is simulated, pressure detection on different positions of the two sides of the composite beam is achieved, and the authenticity of the detection result is improved.

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 discloses a vibration noise analysis method for a combined box girder bridge with an axle coupling effect, and belongs to the technical field of bridge engineering. The method comprises the following steps: S1, establishing a train-track-bridge coupled vibration model of a high-speed railway steel-concrete combined box girder bridge, and compiling a train-track-bridge coupled vibration simulation analysis program based on a Matlab language and Ansys finite element software; s2, establishing a low-frequency noise prediction model in the steel-concrete combined box girder bridge of the high-speed railway, and obtaining a low-frequency noise radiation rule of a bridge structure; s3, establishing a medium-high noise prediction model of the steel-concrete combined box girder bridge of the high-speed railway, and performing numerical simulation on medium-high frequency radiation noise of a bridge structure; and S4, analyzing the influence parameters of the vibration noise of the steel-concrete combined box girder bridge of the high-speed railway in combination with the models established in the steps S1 to S3. The technical scheme is used for analyzing vibration and noise conditions of the steel-concrete composite beam applied to the field of railroad bridges.

The utility model discloses a large-span multi-span greenhouse which comprises a plurality of supporting units formed by fixedly connecting a plurality of combined beam frames end to end, a plurality of upper longitudinal beams and a plurality of lower longitudinal beams are arranged among the supporting units, and the upper longitudinal beams and the lower longitudinal beams are distributed in a staggered mode. Each combined beam frame comprises two stand columns, a cross beam, a suspension cable and a plurality of main ribs, every two adjacent combined beam frames share the same stand column, the cross beam is erected between the two stand columns, the upper ends and the lower ends of the main ribs are fixedly connected with the upper longitudinal beam and the lower longitudinal beam respectively, the lower longitudinal beam is fixedly arranged on the cross beam, and the suspension cable is arranged on the main ribs. The two ends of each suspension cable are fixedly arranged on the two corresponding stand columns, and greenhouse covering materials are installed on a net frame formed among the main ribs, the upper longitudinal beams and the lower longitudinal beams. The main ribs are made of rigid materials or flexible materials. The utility model not only replaces the conventional glass greenhouse and the conventional multi-span film greenhouse which respectively use a truss structure and an arch structure, but also has the advantages of large span and material conservation.

The invention provides a modular assembly type steel reinforced concrete combined beam column joint and an assembly method thereof. The modular assembly type steel reinforced concrete combined beam column joint comprises a joint core, a steel reinforced concrete combined column, a steel reinforced concrete combined beam, a plurality of single-side self-locking high-strength bolts and a plurality of common high-strength bolts. The node core comprises a node core cavity, at least one connecting end and at least one group of L-shaped connecting end plates; threaded holes are formed in the corresponding positions of the L-shaped connecting end plates. The steel reinforced concrete combination column comprises a column-shaped steel framework and column concrete wrapping the column-shaped steel framework. Bolt holes are formed in the corresponding positions of the columnar steel framework; bolt holes, grouting holes and grout outlet holes are reserved in the corresponding positions of the column concrete; the steel reinforced concrete composite beam comprises a beam shoe, beam H-shaped steel and beam concrete wrapping the beam H-shaped steel. Bolt holes are formed in the corresponding positions of the beam H-shaped steel. The beam shoe is used for being connected with the node core. The scheme has the advantages of convenience in field assembly, high connection reliability, short construction period, capability of realizing dry connection and the like.

The invention relates to the technical field of engineering design, in particular to a truss-web type steel-concrete composite beam deflection calculation method and system.The method comprises the steps that a mechanical simplified model of a truss-web type steel-concrete composite beam is built, calculation assumption is determined, and a calculation scheme is obtained; determining the acting mode of the external load on the composite beam; basic calculation parameters of the combined beam mechanical simplified model are determined; according to the action mode, calculating a rigidity reduction coefficient of the simply supported beam caused by shear deformation of a truss web member, a slippage effect of a steel-concrete connection interface and local deformation of a node under the action of different loads; calculating the equivalent flexural rigidity of the truss-web type composite beam; and calculating the deflection of the truss-web type steel-concrete composite beam under the action of different loads. By means of the method, the problem that an existing calculation method is poor in pertinence and applicability is effectively solved, so that the stress condition of the truss web type steel-concrete composite beam structure is correctly reflected; according to the method, multiple influences caused by discontinuity of the truss web members, including shear deformation of the truss web members, a slippage effect of a steel-concrete connection interface and additional deflection caused by local deformation of the nodes, are considered, and the midspan deflection of the truss-web type steel-concrete combined simply supported beam can be conveniently evaluated.

The invention relates to the technical field of bridge construction, and provides a construction method of a cable-stayed-continuous cooperative system composite beam bridge, which does not need to arrange a large batch of prestressed corrugated pipes and steel beams to ensure the use performance of a bridge deck slab, fully utilizes the structural characteristics of the cable-stayed-continuous cooperative system composite beam bridge, and improves the construction efficiency of the cable-stayed-continuous cooperative system composite beam bridge. By changing the overlapping sequence of the continuous composite beam bridge deck slabs, it is guaranteed that the bridge deck slabs in the hogging moment area of the continuous composite beam do not generate tensile stress, the bridge deck slabs in the sagging moment area generate pressure stress reserve, and by increasing the tension stay cable force, the continuous composite beam moves upwards close to a side main beam of the cable-stayed bridge and moves downwards close to a side span side main beam; the bridge deck slab generates compressive stress, the steel main beam generates tensile stress, the compressive property of concrete materials and the tensile property of steel are fully played, the material utilization rate is increased, the compressive pre-stress of the bridge deck slab is completed through internal force distribution of the composite beam, the construction method is simple and operable, the structural stress is clear, and the reasonability and safety of the structural stress are guaranteed.

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

The invention belongs to the technical field of bridge design, particularly relates to a plastic design theory-based steel-concrete composite beam flexural capacity optimization design calculation method, and aims to carry out section optimization analysis on a steel-concrete composite beam according to a principle that a bending moment design value of the steel-concrete composite beam is equal to plastic flexural capacity as optimal control, so as to obtain the optimal flexural capacity of the steel-concrete composite beam. And the optimal section size of the steel-concrete composite beam is obtained. The calculation method has the advantages that the standard is relatively unified, the potential of the material can be relatively well exerted, and the method is not too conservative.

The invention discloses a calculation method and a computer system for shear bearing capacity of a profile steel-ultra-high performance concrete composite beam with a composite web. The calculation method comprises the following steps: step 1, obtaining shear bearing capacity Vu and HRS provided by the profile steel web; 2, the shear bearing capacity Vu, UHPC provided by the ultra-high performance concrete web is obtained, and Vu, UHPC = Vc + Vf + Vs; and 3, the shear capacity Vu of the profile steel-ultra-high performance concrete composite beam with the composite web is obtained, and Vu = Vu, HRS + Vu, UHPC. The calculation method provided by the invention can be well suitable for the section steel-ultra-high performance concrete composite beam with the composite web, and has good precision and reliability.

The invention relates to a prefabricated steel concrete beam, a prefabricated steel concrete combined beam column and a production method thereof, the prefabricated steel concrete beam comprises a prefabricated U-shaped beam frame body, a U-shaped groove formed by a bottom steel plate and webs on two sides, a beam shell with a cavity formed in the middle and a pouring opening formed in the upper part, and at least one connecting part is arranged between the webs on the two sides; the upper reinforcing profile steel is arranged on the upper end face of the side web and at least covers the upper end face and the outer side face of the side web; the lower reinforced profile steel is arranged on the lower end face of the side web and at least covers the lower end face and the inner side face of the side web; the reinforced connecting section steel is arranged at the upper part of the pouring opening of the beam shell at intervals and is welded between the upper reinforced section steel; the beam end connecting steel plate is arranged on the bottom steel plate, the bottom of the connecting plate is connected with the bottom steel plate, the connecting plate is perpendicular to the bottom steel plate, and the beam end connecting steel plate partially extends out of the outer end of the bottom steel plate, partially extends into the bottom steel plate and is used for being connected with external beams and columns. The device can be assembled and transported on a production line, and is reliable in quality, high in efficiency and low in cost.

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 invention relates to the technical field of bridge construction, and discloses a method for calculating the rigidity of a composite beam connected by high-strength bolts, which comprises the following steps of: considering the most unfavorable load possibly occurring in a normal use stage and a construction stage during calculation, calculating a standard value of the most unfavorable load combination on the composite beam, and setting a mid-span displacement judgment value at the same time. The method analyzes the stress state of the steel-concrete interface under the action of various loads, can accurately capture the critical point of interface shear stress and friction failure, can accurately simulate the nonlinear change rule of the equivalent stiffness of the composite beam along with the loads by adopting different stiffness calculation formulas, and meanwhile, the design method systematically considers multiple influence factors, and the design method is simple and convenient. According to the method, the nonlinear mechanism of a bolt connection area is simulated, a relatively accurate displacement value can be given, economic evaluation is considered, and the method is a relatively comprehensive composite beam design analysis method.

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 relates to the technical field of bridge deck slab connecting piece structures, in particular to a composite beam prefabricated concrete bridge deck slab connecting piece structure. According to the technical scheme, the bridge deck comprises a first concrete bridge deck body and a second concrete bridge deck body, and the ends, close to each other, of the first concrete bridge deck body and the second concrete bridge deck body are provided with pouring connecting grooves and connecting pieces correspondingly; the ends, away from each other, of the first concrete bridge deck and the second concrete bridge deck are provided with connecting pieces and pouring connecting grooves correspondingly. During connection construction, the multiple sets of reinforcing ribs are inserted into the multiple sets of through openings correspondingly, concrete grout can be injected into the pouring connection grooves when the concrete bridge deck slabs are connected, the concrete grout enters the inner grooves in the inner sides of the through openings through the pouring openings, and the reinforcing ribs are more firmly fixed into the inner grooves; the edge locking pieces and the edge groove assemblies are arranged at the two ends of the adjacent first concrete bridge deck slab and the second concrete bridge deck slab, so that the concrete bridge deck slabs can be effectively prevented from cracking to generate gaps.

The invention discloses a variable cross-section continuous composite beam bending moment and displacement calculation method. The method comprises the following steps: S1, segmenting a variable cross-section continuous composite beam structure; s2, calculating anti-bending inertia moments of combined sections of different beam sections, and segmenting the variable-section continuous combined beam according to the anti-bending inertia moments of the sections to obtain a segmented uniform-section model; s3, geometric morphology equivalence is conducted on the variable-cross-section continuous composite beam according to a segmented uniform-cross-section model, half span is selected through symmetry to conduct theoretical analysis calculation, and the bending moment Mr at the segment point of the equivalent model section is obtained; s4, determining an actual inflection point position, and according to the actual inflection point position, performing further equivalent segmentation on the variable cross-section continuous composite beam; and S5, dividing the half-span variable cross-section continuous composite beam into three sections according to the positions of the cross-section segmentation points and the actual inflection points, establishing an equation based on the stress balance and deformation coordination relationship of the cross-section segmentation points and the actual inflection points, and providing a typical cross-section displacement, corner and bending moment calculation method.

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 provides a pier top connecting structure of a composite structure bridge based on steel and concrete and a construction method. A cross beam pouring area is formed between the ends of every two adjacent standard simply-supported units, and end steel plates, second shear nails, second tooth keys and fourth bridge floor post-pouring areas are arranged on composite beams participating in butt joint in the standard simply-supported units; a plurality of second tooth keys are arranged on the end face, close to the cross beam pouring area, of the concrete rib plate, a fourth bridge deck post-pouring area is located at the end, close to the cross beam pouring area, of the bridge deck slab, an end steel plate is arranged at the end, close to the cross beam pouring area, of the steel beam, and a plurality of second shear nails are arranged on the face, away from the steel beam, of the end steel plate; reinforcing steel bars are arranged in the cross beam pouring area and the fourth bridge floor post-pouring areas of the two adjacent standard simply-supported units, and concrete is poured together in the cross beam pouring area to form a connecting cross beam. The problem that a traditional simply-supported variable continuous structure cannot adapt to system conversion between composite beams in a multi-material composite web form is solved.

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.