1847 results about "Box girder" patented technology

The invention relates to the technical field of bridge construction, in particular to an intelligent cleaning device and method for a box girder side formwork. The device comprises a mobile platform, a control device, a mechanical arm assembly, a cleaning device, an infrared induction sensor, a dust collection device, a multispectral visual recognition module, a 3D environment modeling module, a path planning module, a cleaning quality detection module and a self-adaptive learning database. The multispectral visual recognition module recognizes the stain type and the adhesion strength. The 3D environment modeling module is used for constructing a three-dimensional point cloud model of a working area in real time; the path planning module generates an optimal cleaning path based on a reinforcement learning algorithm; the cleaning quality detection module detects residual stains and triggers secondary cleaning; the adaptive learning database stores historical cleaning data and optimizes a cleaning strategy through a machine learning model. The full-process automatic cleaning operation of the box girder side form can be achieved, and the comprehensive functions of dirt recognition, autonomous path planning, efficient cleaning, real-time detection and the like are achieved.

The invention discloses a multi-sensor fusion-based suspended casting box girder hanging basket state monitoring method and system, and relates to the technical field of intelligent monitoring of engineering equipment. The method comprises the following steps: collecting deformation monitoring data and environment data of a hanging basket system in an operation process; constructing a hanging basket system deformation quantity prediction model taking the deformation monitoring data and the environment data as input; training the prediction model by using historical monitoring data, and minimizing a prediction error by adjusting model parameters; and outputting a hanging basket system deformation quantity prediction result by using the trained prediction model, and effectively improving the precision and reliability of deformation quantity prediction by combining a convolutional neural network and a long-short-term memory network, thereby providing powerful support for safety monitoring and quality control of bridge construction.

The invention discloses a concrete box girder defect automatic detection method and system based on deep learning, and the method comprises the steps: obtaining a visible light image, a laser point cloud and an acoustic emission signal of a box girder, carrying out the data fusion operation, generating new box girder data, setting a defect detection model, and according to the new box girder data, carrying out the automatic detection of the defect of the concrete box girder. Identifying cracks and damages on the box girder; setting a risk assessment model, and calculating a risk index of the box girder according to the new box girder data and cracks and damages on the box girder; and setting a plurality of preset risk grading thresholds, and performing defect risk grading on the box girder in combination with the risk index so as to complete defect detection.

The invention relates to the technical field of box girder reinforcement framework machining, in particular to a bottom web stirrup integrated machining single-machine-head bending device and a forming method of the bottom web stirrup integrated machining single-machine-head bending device. The bending device comprises a straightening mechanism, a feeding and bending mechanism, a transferring mechanism, a welding device and a discharging mechanism. The straightening mechanism comprises a steel bar straightening machine; the feeding and bending mechanism comprises a bending platform, a bending head is arranged in the center of the bending platform, and a steel bar traction device is arranged between the bending head and the straightening mechanism. A reinforcing steel bar cutting device is further arranged between the bending head and the reinforcing steel bar traction device; a regular pushing device is arranged on one side of the bending platform; the transfer mechanism comprises a transfer gripper; the welding device is used for welding the stirrup meshes into an integrated structure; and the discharging mechanism comprises a discharging gripper. According to the bending device, all construction processes for producing the stirrup meshes are smoothly joined, the stirrup mesh bending operation is more efficient, the operation intensity of constructors can be reduced, and the production efficiency of the bottom web stirrup meshes is improved.

The invention belongs to the technical field of steel reinforcement framework three-dimensional reconstruction, and particularly discloses an automatic high-precision three-dimensional dense reconstruction method for a box girder steel reinforcement framework, which comprises the following steps of: dividing a scanning area into a plurality of sub-areas according to a depth image by moving an inspection robot along the steel reinforcement framework, and performing multi-angle local scanning in each sub-area; constructing a local point cloud model by combining camera poses during acquisition, further calculating a relative spatial transformation relationship by using an overlapping region between adjacent local models, constructing a pose map and implementing global optimization, and uniformly adjusting the poses of the local models in a world coordinate system; and finally, all corrected local point clouds are fused to generate a complete global three-dimensional model, so that collaborative reconstruction operation of domain-divided scanning, segmentation reconstruction and global optimization is realized, frame-by-frame accumulation of errors in traditional scanning-while-splicing reconstruction is effectively blocked, long-distance drift is remarkably inhibited, and the precision of three-dimensional reconstruction of the reinforcement cage is greatly improved.

The invention provides a concrete elastic-plastic damage constitutive model construction method and system, belongs to the field of computers, and solves the problems that in the prior art, an integral or gradient enhanced regularization method is adopted to establish a non-local constitutive model, but the two methods require relatively fine finite element grid division, and numerical value implementation is very difficult. Comprising the following steps: 1, determining a damage variable, nominal stress, effective stress and an elastic-plastic damage stress-strain relationship, and decomposing the effective stress according to tension and compression characteristics; 2, in the effective stress space, a concrete elastic-plastic damage constitutive model is established; and step 3, based on an energy regularization method, determining a tensile damage variable, a compression damage variable and a corresponding stress-strain relationship, and in combination with a plastic loading and unloading rule, constructing a concrete elastic-plastic damage constitutive model based on energy regularization. The invention provides the construction method of the PC box girder concrete elastic-plastic damage constitutive model under the non-uniform constraint, and the application range is wide.

The multi-component non-landing construction bridging system comprises at least two main beams, the main beams are supported at the tops of box beams, cover beams or pier bodies through legs, supporting cross beams are arranged between the legs and the pier bodies, and the supporting cross beams stretch across the tops of the multiple pier bodies; at least one crown block is arranged at the top of the main beam, and the crown block is provided with a hoisting trolley capable of moving transversely and used for hoisting and installing a cover beam and a box beam. The bent cap is divided into two pieces in the longitudinal direction, the two pieces of bent cap are hoisted respectively, and the two pieces of bent cap are fixedly connected with each other when located at the top of the pier body. By the adoption of the structure, under the constraint that the legs do not fall to the ground, hoisting construction of the bent cap and the small box girder can be completed, and the device is suitable for the construction working conditions of three-dimensional overlapped elevated frames and spanning existing roads. And through optimization of the construction process, hoisting construction of the cover beam and the small box beam can be achieved within the range of the main beam only exceeding the length of two spans. By means of the scheme that the bent cap is installed in a split mode, the weight of the bent cap of the large-width bridge is greatly reduced.

The invention discloses a prefabricated box girder reinforcement cage forming method suitable for factory manufacturing, which is characterized in that a box girder reinforcement cage obtained by assembling an existing closed hoop is improved into a structure of a bottom web double-U mesh and a top plate double-layer mesh according to a'double-U + top plate 'forming and assembling thought; each type of reinforcing mesh can be automatically produced by bending, binding and welding equipment at the same time, the mesh is moved to a reinforcing steel bar framework assembling area through a special lifting appliance to form a box girder reinforcing steel bar framework, and meanwhile prestressed pipeline strand penetrating installation is carried out. The construction quality problems of strand pulling displacement, deformation damage and the like of the prestressed pipeline are solved, the subsequent prestressed tension safety quality is guaranteed, and the service life of the prefabricated PC box girder is prolonged.

The automatic production equipment for the U-shaped reinforcing mesh in the box girder comprises a straightening structure, a bending structure and a welding assembly, the straightening structure is arranged on the upstream portion of the bending structure, and the welding assembly is arranged on the downstream portion of the bending structure; the reinforcing steel bars sequentially pass through the straightening structures, the bending structures and the welding assemblies to form an inner U-shaped reinforcing steel bar net. Steel bars are automatically produced to form inner U-shaped steel bars, then the inner U-shaped steel bars are in lap joint with longitudinal steel bars conveyed in the limiting holes, a plurality of lap joint welding spots are welded and fixed through the first welding gun and the second welding gun, the inner U-shaped steel bar mesh with the stable structure is formed, automatic control is achieved in the whole process, and the production efficiency is high; meanwhile, manual intervention is avoided, and the formed inner U-shaped reinforcing mesh is good in consistency, high in strength and suitable for continuous large-scale production.

The invention relates to a method for monitoring prefabrication and assembly errors of a steel box laminated continuous box girder bridge, and belongs to the technical field of data processing. The method comprises the following steps: collecting prefabrication and assembly error monitoring data of the steel box superposed continuous box girder bridge, and marking the data; an error prediction model is constructed, wherein the error prediction model comprises a physical constraint feature fusion layer, a causal convolution layer, a Bayesian uncertainty propagation layer, a residual attention mechanism module and a dual-channel gating fusion module; training the model by adopting the marked data; in the training process, optimizing the model by constructing mixed loss to obtain a trained model; and aligning timestamps of the collected structure parameters, construction processes, environment parameters and measurement and state parameters of the new prefabricated segment, integrating the parameters into an input sample isomorphic with the training set, and inputting the input sample into the trained model to obtain a prediction result. According to the invention, systematic deviation can be effectively eliminated, and high-robustness and high-precision error prediction is realized.

The invention relates to an automatic binding system for a reinforcement cage and application of the automatic binding system. The system comprises a control station, a binding jig frame, a four-way rail arranged in the circumferential direction of the binding jig frame, a four-way RGV arranged in a sliding mode in cooperation with the four-way rail, a sub-control piece, a mechanical arm, an identification piece and a binding piece, wherein the sub-control piece and the mechanical arm are arranged on the four-way RGV, and the identification piece and the binding piece are arranged at the output end of the mechanical arm. The control station is in communication connection with the sub-control piece and is used for directly or indirectly controlling the four-way RGV, the mechanical arm, the identification piece and the binding piece; the automatic binding system for the reinforcement cage is applied to binding of the reinforcement cages of T-shaped beams, box beams, pier columns and cover beams. The method has the advantages of improving the production efficiency and ensuring the batch steel bar binding result, and is suitable for batch production of steel bar cages of T beams, box beams, pier columns and cover beams.

The invention provides a box girder defect recognition method and system based on structured light and deep reinforcement learning, and relates to the technical field of box girder defect recognizing.The method comprises the steps that equipment integration and joint calibration are conducted on a to-be-detected box girder component, structured light projection is conducted according to a preset track, and a to-be-detected box girder component is obtained; the method comprises the following steps: triggering an event camera to image by utilizing controlled stroboscopic scanning of structured light, obtaining an event stream and a structured light depth map, carrying out representation conversion and multi-modal alignment, obtaining multi-modal mapping alignment data to carry out primary defect identification, obtaining an initial defect identification result, and triggering a deep reinforcement learning active perceptron to carry out perception strategy analysis. And obtaining a perception strategy analysis result, and carrying out deepening defect identification on the to-be-detected box girder component to obtain a defect identification result. The technical problems that in the prior art, box girder defect detection is low in detection efficiency, not high in accuracy and poor in detection comprehensiveness are solved. The technical effect of improving the efficiency, accuracy and comprehensiveness of box girder defect detection is achieved.

The invention discloses a variable cross-section cast-in-place box girder arc-shaped wing plate supporting structure which comprises a disc buckle full supporting frame, an adjusting vertical rod is arranged at the upper end of the disc buckle full supporting frame, a jacking is arranged at the upper end of the adjusting vertical rod, main keels are arranged at the upper end of the jacking, multiple sets of auxiliary keels are arranged at the upper ends of two main keels, and formworks are arranged at the upper ends of the auxiliary keels. A positioning strip is arranged on one side of the upper end of the template; a height adjusting block is arranged on one side of the positioning strip The arc-shaped truss is arranged obliquely above the formwork, and one end of the arc-shaped truss is located at the upper end of the height adjusting block. The method has the advantages that the arc-shaped truss is machined according to the arc-shaped size of the box girder wing plate, the size and radian precision is high, the construction quality is easy to guarantee, the applicability is high, the variable cross-section height is partitioned, the height is adjusted through the height adjusting blocks, the machining model number of the arc-shaped truss is reduced, and the machining cost is reduced. Only several standard parts are adopted for machining, the problem that the sizes of wing plates of the variable cross-section sections are inconsistent can be solved, the positioning strips are adopted for installation and positioning, and the installation deviation of the arc-shaped truss is reduced.

The invention discloses a fabricated steel-UHPC external prestressing combined box girder and a construction method and application thereof, and relates to the technical field of bridge engineering, the fabricated steel-UHPC external prestressing combined box girder comprises a prefabricated steel-UHPC combined top plate, a prefabricated steel-UHPC combined bottom plate, a prefabricated steel-UHPC combined web plate, a steel diaphragm plate and an external prestressing system. The box girders are formed by combining prefabricated slabs, the prefabricated web plates are firmly connected with the prefabricated top plate and the prefabricated bottom plate through welded steel plates and post-poured UHPC, and arrangement and tensioning of external prestress are achieved by arranging steel anchor boxes and steering gears in box chambers. According to the combined box girder, the steel and the UHPC are combined to form a structural form that the steel plate is wrapped by the UHPC, and the advantages of high strength, high durability, high toughness, high compactness, low creep and the like of the UHPC and the advantages of high strength, high elastic modulus and weldability of steel are fully utilized, so that the box girder has the advantages of being excellent in structural stress performance, light in overall weight, good in durability, small in later-stage deformation, low in cost and the like. And the hoisting device is especially suitable for bridges in urban rail transit or urban railways.

The invention provides a quality control method and system for a small box girder, and the method comprises the following steps: constructing a small box girder design BIM model according to a bridge design drawing; converting the BIM design model of the small box girder into discrete point cloud; obtaining a prefabricated field template point cloud, and preprocessing the prefabricated field template point cloud; performing registration on the point cloud model and the BIM model; and selecting a control point on the registered point cloud model as a reference for external mold control lofting, and calculating and evaluating field lofting data. According to the quality control method and system for the small box girder provided by the invention, the point cloud is generated by adopting BIM model interpolation, high-precision registration is completed in combination with a point cloud-point cloud registration algorithm, and the registration effect is evaluated based on the root-mean-square error. And closed-loop quality control from design to construction reduces manual intervention and can realize full-process digitization. And through algorithm fusion and error registration, engineering requirements are met, and the precision is effectively improved. The problems that a traditional method is low in precision and poor in efficiency are solved.

The invention belongs to the technical field of box girder reinforcement cage machining, and particularly relates to a bottom web stirrup integrated machining multi-machine-head bending device and a forming method of the bottom web stirrup integrated machining multi-machine-head bending device. The bending device comprises a discharging mechanism, a storage mechanism, a bending mechanism, a transferring mechanism, a welding mechanism and a discharging mechanism. The discharging mechanism comprises a straightening cut-off machine. The storage mechanism is used for discharging the straightened reinforcing steel bars into the bending mechanism. The bending mechanism comprises a bending platform and a plurality of bending heads which are arranged in parallel; the plurality of bending heads divide a steel bar into two parts, namely an inner ring bar and an outer ring bar, and the two parts are bent and folded to form a stirrup mesh; the transfer mechanism comprises a transfer gripper which is used for gripping the stirrup mesh and transferring the stirrup mesh into the welding mechanism; the welding mechanism is used for welding the stirrup meshes into an integrated structure; and the discharging mechanism comprises a discharging gripper which is used for gripping the stirrup meshes in the welding mechanism and discharging the stirrup meshes. According to the bending device, all construction processes for producing the stirrup meshes are smoothly joined, the operation intensity is reduced, and the production efficiency of the stirrup meshes is improved.

The invention provides a box girder concrete pouring path tracking method and system based on a Beidou system. The method comprises the following steps: firstly, constructing a box girder BIM model, and carrying out layered and segmented subdivision according to a preset rule to form a plurality of three-dimensional latticed pouring areas; material distribution opening positioning data are obtained in real time through a Beidou system, and matching calibration is conducted on the material distribution opening positioning data and BIM model space coordinates. And based on the calibrated model, the initial position and the target position of the pouring arm are determined in combination with the geometric parameters of the pouring area and a preset sequence rule. And taking the minimum material distribution time and the maximum material distribution uniformity as optimization objectives, and considering mechanical motion limitation to generate an optimal pouring path. In the pouring process, the position of a pouring arm is tracked in real time through Beidou positioning data, pouring is completed according to a planned path, meanwhile, pouring state identifiers of all areas in the BIM model are dynamically updated, and full-process visual tracking is achieved. According to the technical scheme, the construction precision and the intelligent level of box girder concrete pouring are improved.

The invention discloses an integral dismantling method for a rigid frame bridge hanging basket formwork, and relates to the technical field of bridge engineering construction. The problems that in the prior art, the rigid frame bridge hanging basket formwork dismantling efficiency is low, potential safety hazards are high, and cost is high are solved. The dismantling method comprises the following steps of: pre-burying a winch anchor bolt to anchor a winch; loosening a hanging basket anchor system to separate a hanging basket bottom die from a concrete box girder; arranging four winches to be matched with fixed pulleys; synchronously lifting the hanging basket bottom die for static load test, then synchronously lowering the hanging basket bottom die to the ground, and decomposing and dismantling the hanging basket bottom die on the ground. And the hanging basket truss is disassembled on the bridge floor. The integral dismantling method for the hanging basket formwork of the rigid frame bridge is used for dismantling the hanging basket bottom formwork of the rigid frame bridge, an integral dismantling mode is adopted, high-altitude split operation of the hanging basket bottom formwork is converted into integral ground dismantling, the operation time is shortened, and the dismantling efficiency is improved; the template loss is reduced, and the cost is reduced; aloft work is reduced, and potential safety hazards are reduced. The method is particularly suitable for large-span bridge engineering crossing rivers and seas or expressways.

The invention discloses a split type three-box girder nonlinear vortex vibration steady-state amplitude intelligent prediction method, belongs to the field of bridge vortex-induced vibration control, and aims to solve the problem of low accuracy of three-box girder vortex vibration nonlinear modeling and amplitude prediction. The method comprises the following steps: acquiring displacement time sequence data through a reduced scale model wind tunnel test, preprocessing to obtain displacement, speed and acceleration dimensionless data, and dividing a data set; constructing a candidate function library containing high-order polynomial terms of the primary function; performing nonlinear system sparse recognition by taking acceleration data as a target item and combining an improved algorithm to obtain a preliminary feature set; a final feature set is obtained through energy-statistics-self-adaption three-stage screening; and finally, constructing a control equation to predict the steady-state amplitude. The method can accurately predict amplitude, coincide test and real bridge observation results, and is less in computing resource occupation and high in numerical value precision.

The utility model discloses a prefabricated box girder concrete automatic spraying maintenance device which comprises two bases, each base is fixedly connected with a vertical pipe, the interior of each vertical pipe is connected with a first telescopic pipe in a sliding mode, the top ends of the two first telescopic pipes are fixedly communicated with transverse pipes, the interiors of the two transverse pipes are connected with second telescopic pipes in a sliding mode, and the second telescopic pipes are fixedly communicated with the top ends of the second telescopic pipes. The ends, away from the transverse pipe, of the two second telescopic pipes fixedly communicate with the top ends of the other two first telescopic pipes, and each vertical pipe is provided with a first hydraulic cylinder used for pushing the corresponding first telescopic pipe. Through mutual cooperation of the vertical pipe, the first telescopic pipe, the first hydraulic cylinder, the transverse pipe, the second telescopic pipe and the second hydraulic cylinder, the use height and width of the device can be flexibly adjusted, so that the device can be suitable for spraying maintenance of prefabricated box girders of different specifications, the operation mode is rapid, the structure is simple and reliable, and the maintenance cost is low. And a water source can be fully sprayed to the prefabricated box girder, so that the water source is saved.

The invention provides box girder bottom and web reinforcement cage framework streamlined production equipment, and belongs to the technical field of box girder prefabrication processing. The box girder bottom and web reinforcement cage framework streamlined production equipment comprises a moving seat which is linearly and slidably mounted on the ground, and a longitudinal bar fixing assembly is arranged at one end of a first rail; an automatic welding machine, a tidying mechanism and a stock bin are sequentially arranged on the moving seat in the direction that the moving seat slides away from the longitudinal bar fixing assembly, the stock bin is used for horizontally arranging and placing the combined stirrups, shifting assemblies are further arranged on the moving seat and located on the two sides of the stock bin, and the tidying mechanism is used for fixing the combined stirrups and positioning longitudinal bars; the automatic welding machine is used for welding the joints of the combined stirrups and the longitudinal bars on the arranging mechanism, and a supporting assembly is arranged below the moving seat. The combined stirrups can be taken out of the stock bin through actions of the arranging mechanism and the material stirring machine, then the automatic welding machine is used for welding, the moving seat moves backwards by a certain distance after one round of welding, the next round of welding of the combined stirrups is carried out, and the welding and manufacturing efficiency of a reinforcement cage framework is improved.

The utility model belongs to the technical field of steel-concrete bridges, and particularly relates to a steel pipe concrete column type pier and steel box girder connecting structure with a steel sleeve reinforcing function. The utility model provides a steel pipe concrete column type pier and steel box girder connecting structure with a steel sleeve reinforcing function, which can be used for reinforcing a steel box girder by arranging in-pipe pre-cast concrete, a box girder bottom plate, a bottom plate opening, cast-in-place concrete, a vertical reinforcing steel bar, a penetrating hole, an inserting sleeve unit and an annular reinforcing frame body unit on a pier steel pipe. Therefore, the inserting sleeve unit and the annular reinforcing frame body unit can achieve the reinforced connection effect of a steel structure framework in cast-in-place concrete, it is guaranteed that the steel-concrete connecting structure has the tensile effect of steel and the compressive effect of concrete, and the connecting structure can be stably used for a long time.

The invention discloses a suspended pouring box girder hanging basket state monitoring method and system based on image recognition, and relates to the field of suspended pouring box girder hanging basket state monitoring. The method comprises the following steps: dynamically acquiring multi-source data such as an identification image, stress data, environment data and external load of a hanging basket, extracting first deformation data based on the identification image, and mapping the stress data and the environment data into second deformation data and third deformation data respectively; performing fusion processing on the deformation data to obtain fused deformation data; estimating deformation interference of the hanging basket based on the fused deformation data and the environment data, and obtaining interference estimation; constructing a dynamic model between the hanging basket deformation quantity and external load and interference estimation; and fitting the dynamic model by using the collected multi-source data, correcting the deformation quantity by using an observation equation and a Kalman filtering algorithm, and carrying out risk early warning according to the corrected hanging basket deformation quantity and a set deformation quantity threshold value.

The invention discloses a transverse fixed axle assembly capable of achieving Ackerman steering through mechanical linkage, and belongs to the technical field of engineering vehicle chassis. A rear axle is transversely and rigidly fixed to a frame through a shear-resistant box girder structure, and a front axle is connected to the frame through two springs; the rotating pair structures are symmetrically arranged at the two ends of the axle main body and comprise embedded heavy-duty bearings; one end of the steering knuckle arm is hinged to the axle main body through a rotating pair structure, and the other end is connected with the steering pull rod; one end, far away from the rotating pair structure, of the steering pull rod is connected with the steering oil cylinder; the steering pull rod of the front axle and the steering pull rod of the rear axle are crossed and hinged in an X shape, so that intersection points of axes of the front and rear wheels converge at an instantaneous steering center during steering. Abrasion and slipping of tires can be reduced, steering precision is ensured through a pure mechanical structure, the failure risk of an electric control system is avoided, and the system is suitable for heavy equipment such as mining trucks and port cranes.

The utility model relates to the technical field of prefabricated box girder production, in particular to a movable prefabricated box girder bottom formwork system which comprises multiple sets of equipment bases, a supporting frame is arranged between the left set of equipment bases and the right set of equipment bases, the upper side of the supporting frame is fixedly connected with a bottom formwork, and the upper side of each equipment base is provided with an adjusting assembly. The adjusting assembly comprises a first hydraulic cylinder, a positioning frame, a second hydraulic cylinder, a first side plate, a supporting block, a limiting rod, a second side plate, a limiting clamping block, a cross beam and a sleeving groove, multiple sets of transverse positioning sliding grooves are formed in the upper surface of the equipment base, multiple sets of positioning sliding blocks are fixedly connected to the lower surface of the positioning frame, and the positioning sliding blocks are in sliding connection with the positioning sliding grooves; the first hydraulic cylinder pushes the positioning frame to slide on the surface of the equipment base to quickly adjust the distance between the templates on the left and right sides, and meanwhile, the second side plate slides up and down on the surface of the limiting rod, so that the heights of the templates on the left and right sides are quickly adjusted, the sizes of the templates are conveniently adjusted, and the preparation efficiency of the prefabricated box girder is improved.

The utility model relates to a pushing construction auxiliary device which comprises a connecting block, a supporting plate is arranged at the upper end of the connecting block, a hemispherical block is fixed to the middle of the lower end face of the supporting plate, a hemispherical groove is formed in the middle of the upper end face of the connecting block, a plurality of first blind holes are evenly formed in the upper end face of the connecting block along the circumference, and a pushing block is arranged in each first blind hole. A second blind hole is formed in the lower end face of the connecting block, a piston block is arranged in the second blind hole, the upper end of the second blind hole communicates with the lower end of each first blind hole, and a cavity between the piston block and each ejector block is filled with hydraulic oil. Hydraulic oil in the first blind hole cannot flow back into the second blind hole; the supporting plate and the hemispherical block can freely rotate on the groove, so that the supporting plate can be attached to the box girder under the condition that the lower end face of the box girder is uneven or low in levelness, the contact area between the supporting plate and the box girder is increased, and the jacking effect of the jack is more stable.

The invention discloses a suspension bridge pin shaft fork ear connecting piece load-wear fatigue test device, which comprises a lever prying force application device, a fatigue test device and a fatigue test device, comprising a lever prying support, a fork-shaped lug plate force application plate arranged at the top end of the lever prying support, and a force transmission lever arranged below the fork-shaped lug plate force application plate to drive the fork-shaped lug plate force application plate to move up and down. The torque force application device is used for providing torque, enabling the fork-shaped lug plate to be in close contact with the box girder lug plate and simulating an actual back-twist phenomenon, and comprises an upper layer mechanism and a lower layer mechanism which rotate relatively, and a high-strength torsion spring and a torque sensor which are buckled inside by the upper layer mechanism and the lower layer mechanism; the abrasion sliding device is arranged at the bottom of the lever prying support and connected with the bottom of the torque force application device, and the operation state of the fork-shaped lug plate in an actual structure is simulated, so that the fork-shaped lug plate generates back-twist abrasion damage. According to the invention, a large tonnage, namely the stress state of the connecting piece under an actual bridge load, can be fully simulated through a test, and fatigue test evaluation after wear damage is carried out on the connecting piece.

The utility model discloses a railway simply-supported box girder support embedded hole positioning device which comprises a fixing frame, a plurality of connecting long holes and a plurality of positioning long holes are formed in the fixing frame, and the fixing frame is fixedly connected with a padstone template through bolts at the connecting long holes. And the fixed frame is connected with a plurality of positioners at the plurality of positioning long holes through bolts. The positioning device for the embedded hole of the railway simply-supported box girder support solves the problem that in an existing positioning method, positioning is not accurate due to displacement of a PVC pipe.

The utility model discloses a steel-concrete box girder assembly jig frame, which relates to the technical field of steel-concrete box girder assembly and is characterized in that the top of a support frame is connected with a plurality of groups of limiting frames in a sliding manner, a plurality of groups of jacks are respectively positioned on the periphery of the support frame, the top ends of the jacks are fixedly connected with guide rods, and the top ends of the guide rods are fixedly connected with the support frame; the multiple sets of supporting columns are fixedly connected with the bottom end of the jack. The jack drives the guide rod to vertically move upwards so as to abut against the supporting frame to move to the position with the appropriate elevation of the steel-concrete box girders, and when the two steel-concrete box girders are placed on the supporting frame, the phenomenon that the height of the supporting frame is reduced due to the fact that the height of a ship is reduced is avoided; therefore, it is guaranteed that the reinforced concrete box girder is located at the designed elevation position when placed on the supporting frame, then the assembling accuracy of the reinforced concrete box girder is guaranteed, the periphery of the supporting frame can be adjusted through the four sets of jacks, and therefore the supporting frame is located at the horizontal position.