6334 results about "Pre stress" patented technology

The invention discloses a steel wire rod for a 2400-2460 MPa grade stress corrosion resistant prestressed steel strand, the steel strand and a production method. The steel wire rod comprises the following chemical components in percentage by weight: 0.90-0.97% of C, 0.6-1.2% of Si, 0.2-0.8% of Mn, 0.15-0.45% of Cr, 0.02-0.05% of V, 0.01-0.05% of Nb, less than 0.30% of Ni, less than 0.30% of Cu, less than 0.30% of Mo, less than or equal to 0.008% of S, less than or equal to 0.010% of P, less than or equal to 0.004% of N, less than or equal to 0.0020% of O and the balance of Fe and other inevitable impurities. By optimizing the chemical components and the production process of the wire rod, the strength of the prepared steel strand meets 2400-2460 MPa, the minimum stress corrosion value is 2.5 hours, the median value is 5 hours, and the stress corrosion resistance is obviously superior to that of an existing steel strand.

The invention discloses a steel wire rod for a 2200-2260 MPa grade ultrahigh stress corrosion resistance prestressed steel strand, the steel strand and a production method of the steel strand, and the steel wire rod comprises the following alloy components in percentage by mass: 0.83-0.89% of C, 0.60-1.40% of Si, 0.20-0.80% of Mn, 0.15-0.50% of Cr, less than 0.30% of Cu, less than 0.30% of Ni, less than 0.30% of Mo, 0.01-0.05% of V, 0.001-0.05% of Nb, less than or equal to 0.008% of S, less than or equal to 0.010% of P, less than or equal to 0.0040% of N, less than or equal to 0.0020% of O and the balance of Fe and other inevitable impurities, through component design and a reasonable after-rolling controlled cooling process, the microstructure is refined, the sorbite rate is improved, high strength and plasticity are obtained with low carbon content, the drawing deformation can be reduced, material damage can be reduced, and the corrosion resistance of the steel strand is improved.

The invention discloses an assembly type prestressed self-resetting frame beam column replaceable energy dissipation joint which comprises a joint core area connecting device, a short steel beam connecting piece, an RC frame beam connecting piece, a replaceable energy dissipation device, a self-resetting device, a pin shaft and a friction base plate. The joint core area connecting device comprises a partition plate, a hoop and a short steel beam. The short steel beam connecting piece comprises a fixing plate, an anchoring plate and an outer friction lug plate; the RC frame beam connecting piece comprises an inner friction lug plate, an RC frame beam connecting end plate and embedded H-shaped steel; the hoop is connected with the fixing plate through the short steel beam, and the outer friction lug plate, the inner friction lug plate and the friction base plate are connected to form a friction energy dissipation device. The pin shaft is in running fit with the friction energy consumption device; the anchoring plate and the RC frame beam connecting end plate are connected through a replaceable energy consumption device; the RC frame beam connecting end plates are connected with the beam longitudinal bars. Two energy consumption devices are ingeniously designed, and the defect that the energy consumption level of the structure can only be in the low level after a single-form energy consumption component loses efficacy is overcome.

The invention provides a pre-stressed anchor cable construction arrangement quality evaluation method, and relates to the field of underground engineering, and the method comprises the following steps: S1, model construction: building three-dimensional numerical models of different anchor rod arrangement schemes; s2, simulation calculation and result evaluation, wherein excavation simulation calculation is executed according to the three-dimensional numerical models of different anchor rod arrangement schemes, and numerical simulation calculation results of surrounding rock deformation, stress distribution, damage and fracture area distribution and supporting structure stress are obtained; evaluating numerical simulation calculation results of different anchor rod arrangement schemes to obtain evaluation indexes, and determining an optimal scheme according to the evaluation indexes. Through the cooperation of the above structures, the method has the following beneficial effects: 1, the evaluation accuracy can be comprehensively improved, and the data is converted into a visual and quantitative evaluation result by constructing a comprehensive evaluation system and applying a data analysis model and algorithm; and secondly, by establishing an error correction model, the deviation between numerical simulation and on-site monitoring data can be accurately calibrated.

Provided in the present invention are an integrated intelligent construction method for a cast-in-place box girder, and a system. The method comprises the following steps: S1, designing a scheme on the basis of BIM; S2, forming and transporting a rebar part; S3, establishing a box girder formwork; S4, testing the precision of the formwork; S5, assembling the rebar part in the formwork; S6, testing the quality of the rebar part; S7, constructing a prestressed pipeline and performing alignment inspection; S7, casting concrete; S8, testing the quality of the concrete; S9, curing the concrete; S10, controlling the quality of curing; and S12, performing prestressed tensioning and grouting inspection. Intelligent integrated box girder construction is realized by means of the above steps. In the present invention, the above solution is used, and intelligent control technology is introduced into a construction method, so that the mechanization, automation and intelligence levels of cast-in-place box girder construction can be improved, thereby greatly improving the construction efficiency, reducing labor intensity, improving on-site management levels, and ensuring construction safety and construction quality.

The invention relates to the technical field of civil engineering, and particularly discloses a tunnel early-high-strength rock anchoring and shotcreting synergistic effect bearing arch active support design method which comprises the following steps: determining a rock anchor bearing arch acting load and establishing a rock anchor bearing arch calculation model; calculating to obtain the most unfavorable section displacement and stress of the rock anchor bearing arch; verifying whether the displacement of the rock anchor bearing arch meets the requirement; a safety evaluation method of the pre-stressed anchor rods is provided, and the safety of the pre-stressed anchor rods is evaluated according to a rock anchor bearing arch calculation result; establishing a sprayed concrete calculation model; calculating to obtain the most unfavorable section displacement and stress of the sprayed concrete; a sprayed concrete safety and durability evaluation method is provided; active support parameters are determined according to the calculation result of the rock anchor bearing arch and the calculation result of the sprayed concrete. By means of the method, the safety and durability of rock-anchor-shotcrete active supporting under different supporting parameters can be simply, rapidly and accurately calculated, reference is provided for tunnel engineering design adopting active supporting, and good engineering value is achieved.

The invention provides a portable stirrup welding device for high pier construction, and relates to the technical field of box girder stirrup welding equipment.The portable stirrup welding device comprises a welding hand-held piece, and a steel bar storage part is installed on the welding hand-held piece; the steel bar storage part is used for storing stirrup connecting bars; a connecting rib pushing piece is mounted on the welding handheld piece; the connecting rib pushing piece is used for pushing stirrup connecting ribs; two stirrup prestress pieces are mounted on the welding handheld piece; the two stirrup prestressed parts are used for pulling stirrups; prestress annealing welding can be achieved, the welding tension degree is poor, meanwhile, the accuracy of welding seams can be affected by deviation of the stirrups, and the problems that the welding efficiency is low, the stirrups are not convenient to automatically correct and the tension degree of the welded stirrups is poor due to the fact that welding work of the stirrups for high pier construction mostly adopts manual handheld welding gun operation are solved.

The invention discloses a steel wire rod for a 2500-2560 MPa grade stress corrosion resistant prestressed steel strand, the steel strand and a production method. The steel wire rod comprises the following chemical components in percentage by mass: 0.95-1.02% of C, 0.8-1.5% of Si, 0.5-1.0% of Mn, 0.25-0.45% of Cr, 0.02-0.08% of V, 0.01-0.05% of Nb, less than 0.30% of Ni, less than 0.30% of Cu, less than 0.30% of Mo, less than or equal to 0.008% of S, less than or equal to 0.010% of P, less than or equal to 0.004% of N, less than or equal to 0.0020% of O and the balance of Fe and other inevitable impurities. By optimizing the chemical components and the production process and refining the microscopic structure, the steel strand prepared from the steel wire rod has high tensile strength, the minimum stress corrosion value is 2.5 hours, the median value is more than 5 hours, and the steel strand shows excellent stress corrosion resistance.

The invention discloses a cavity type mixed tower fan foundation formwork construction method. Comprising the steps of cushion layer pouring, pay-off, cavity foundation slab steel bar binding, annular support system erecting, foundation lower inner formwork supporting and inner support frame body arranging, cantilever anchoring end bottom formwork frame body supporting, cantilever anchoring end bottom formwork installing, foundation upper inner formwork supporting and inner support arranging, anchor backing plate and prestressed pipe installing, steel bar binding and annular support system erecting. And a foundation outer formwork is installed. Compared with the prior art, formwork erecting is formed at a time, a foundation is integrally poured, and the overall construction quality is guaranteed; the problem of leakage caused by two-time pouring of a construction joint part is avoided, water stop steel plates are reduced, and materials are saved; the inner supporting frame bodies are radially arranged with the center of the circle and the center of the stand column as a supporting point, and structural stress is reasonable. The supporting frame body is simple in structure, neat, attractive, reasonable in stress and easy to operate, the center stand column is recycled, and construction is efficient.

The invention discloses a fully-recycled prestressed square pile and latticed column combined stand column pile construction method, and belongs to the technical field of green foundation pit supporting. According to the construction method of the fully-recycled prestressed square pile and latticed column combined stand column pile, the prestressed square pile serves as the lower section of the stand column pile and is organically combined with the latticed column, the stand column pile can be pressed into the designed elevation through static pressure equipment, and the construction method has the advantages of being low in construction cost, high in construction efficiency, free of pollution and the like; the stand column piles are integrally pressed into a soil body, the foundation pit soil body is excavated layer by layer, concrete supports and surrounding purlins on the periphery of a foundation pit are supported layer by layer through self-servo hydraulic converters and supporting cross beams, foundation pit construction operation is easy and efficient, and construction is safer and more stable; moreover, after a bottom plate and structural floor slabs of all layers are built, the stand column piles can be recycled by 100%, zero emission is truly achieved, the low-carbon, environment-friendly and green construction effects are achieved, in addition, sensors can be arranged in the pile sections of the prestressed square piles, and foundation pit full-section monitoring and deformation control are achieved.

The invention relates to the technical field of concrete tower footings, and discloses a fabricated prestressed concrete tower footing for a land wind turbine generator and a construction method, a bottom framework is placed in a foundation pit under the supporting action of a corresponding supporting frame, and an annular seat penetrates through the supporting frame and realizes positioning of the supporting frame; the inner framework is supported at the center in the outer framework; under the combined action of the top fixing mechanism and the bottom fixing mechanism, the outer framework and the inner framework are kept vertical. By arranging the inner framework, the outer framework can be supported, the inner framework and the outer framework form a whole after the concrete is solidified, and the overall structural strength is high. Under the combined action of the top fixing mechanism and the bottom fixing mechanism, the space between the outer framework and the inner framework can be ensured to be consistent up and down, and the relative positions of the outer framework and the inner framework are prevented from deviating during concrete pouring, so that the overall structural strength of the outer framework and the inner framework meets the requirement after the concrete is solidified.

The invention discloses a multi-station device for producing and welding box girder prestress positioning meshes, which relates to the technical field of reinforcing mesh production and comprises a straightening machine, a feeding conveying mechanism, a long rib conveying mechanism, a short rib conveying mechanism, an assembling conveying mechanism, a bending mechanism, an assembling carrying mechanism, a welding mechanism and a discharging mechanism. Steel bar raw materials are straightened and cut through the straightener, a feeding outlet of the straightener is connected with a feeding inlet of the feeding conveying mechanism, and long bars and short bars which are straightened and cut are conveyed to the feeding conveying mechanism to be correspondingly conveyed to the long bar conveying mechanism and the short bar conveying mechanism. The conveyed long ribs are conveyed to the bending mechanism to be bent or not to be bent, then the long ribs and the short ribs sequentially pass through the assembling and conveying mechanism, the assembling and carrying mechanism and the welding mechanism to be assembled and welded, and finally the discharging action is achieved through the discharging mechanism. According to the device, full-automatic small box girder welding production is achieved, and the production efficiency is improved.

The invention provides a tunnel prestress self-adaptive yielding steel frame and a construction method, and belongs to the technical field of tunnel engineering.The tunnel prestress self-adaptive yielding steel frame comprises supporting frame bodies and adaptive structures, and every two adjacent supporting frame bodies are connected through the adaptive structures; the adaptive structure comprises a prestress device and a yielding device which are connected in sequence, and the prestress device comprises a prestress releasing structure which tends to extend in the length direction of the prestress device; the yielding device comprises a yielding supporting structure which tends to bend in the length direction of the yielding device. The pre-applied stress of the pre-stress releasing structure is smaller than the yielding initial force of the yielding supporting structure. According to the tunnel prestress self-adaptive yielding steel frame, supporting force is applied to surrounding rock through releasing of the prestress releasing structure, and active supporting force is formed; the surrounding rock pressure is borne by using the compression deformation of the yielding supporting structure and the retraction of the prestress releasing and tensioning structure; effective combination of the prestress device and the yielding device is achieved, and the stability of the supporting structure is improved.

The invention discloses an underground gas storage prestress lining structure and a construction method, and relates to the technical field of underground gas storage, the underground gas storage prestress lining structure comprises a lining layer formed by concrete pouring and internally provided with prestress steel bars; the sealing layer is arranged on the inner side of the lining layer and defines a gas storage chamber; the sliding layer is arranged between the lining layer and the sealing layer. The arrangement of the prestressed reinforcements can counteract part of internal pressure of the gas storage, so that the problem of concrete cracking is relieved. The lining layer is divided into the first lining layer and the second lining layer, the tensioning notch is reserved in the bottom of the first lining layer and provides sufficient tensioning space for the prestressed steel bars, the tensioning effect of the prestressed steel bars is ensured, the second lining layer is formed in the tensioning notch in a pouring mode after the prestressed steel bars are tensioned, and the integrity of the lining layer is ensured. After the sealing layer is constructed, grouting is conducted on the gap between the lining layer and the sliding layer, it is guaranteed that grouting is compact and complete, stress concentration is reduced, and the problem of concrete cracking is further relieved.

The invention discloses a deep learning-based staged tension prestress long-term loss prediction method, which belongs to the field of deep learning, solves the problem of poor prediction result robustness of a traditional prestress measurement method, and comprises the following steps: obtaining bridge original data based on a standard drawing set and a bridge design specification; based on the construction environment conditions and the concrete age, concrete material attributes are calculated; based on bridge original data and concrete material attributes, finite element software is used for simulating prestressed reinforcement staged tensioning processes under different working conditions, and a bridge prestressed reinforcement staged tensioning loss data set is generated; and constructing a prestress loss prediction model based on the multi-layer perceptron neural network, processing the staged tensioning loss data set of the bridge prestressed reinforcement based on the prestress loss prediction model, and outputting a prediction result of long-term loss caused by shrinkage and creep of the prestressed reinforcement. According to the method, the stress loss of the prestressed reinforcement can be effectively predicted, and the prediction robustness and accuracy are improved.

The invention discloses a method for predicting the damage of a prestressed concrete cylinder pipe in a complex environment, and relates to the technical field of pipeline structure health monitoring, and the method comprises the steps: collecting multi-physical field data through deploying multiple types of sensors, transmitting the data to a central monitoring system in a wireless manner, carrying out the standardized preprocessing, and obtaining a multi-source fusion data set; a salt migration driving index dsa, a stress disturbance induction index yry and an electrochemical activity potential index che are constructed, a comprehensive corrosion risk index SCR is obtained, and corrosion behavior evaluation is carried out. And when the corrosion behavior is evaluated as a disturbance sign, a corrosion change prediction index CAR is further calculated according to time sequence evolution forming a corrosion risk index SCR, grading evaluation and transition identification of the corrosion state are realized, an evaluation result is stored in a database, and a corrosion risk evolution trend is presented through a visual chart. The method supports early warning and emergency response decision making, and has high adaptability and engineering practicability without adding hardware.

The invention discloses a large transport vehicle bridge safety assessment method based on fuzzy comprehensive evaluation, which comprises the following steps: constructing a bridge bearing capacity reduction coefficient model, integrating four factors of material performance degradation, structural damage, environmental corrosion and load combination, and determining index weights by adopting an analytic hierarchy process; and a multi-stage evaluation system is established in combination with a fuzzy mathematics theory. A prestressed concrete continuous beam bridge in Jiangsu section of Jinghai highway is taken as an object, finite element simulation is used for analyzing the load effect of large vehicles under independent and mixed passing conditions, and verification shows that when the large vehicles pass at the mixing rate of 20%, the most unfavorable section safety coefficient of the bridge reaches 1.35, and the standard requirements are met. According to the method, fuzzy mathematics and structural mechanics analysis are creatively fused, a standardized process of parameter collection, model calculation and safety judgment is established, the efficiency is improved by 40% or above compared with a traditional static load test, the method is applied to transportation examination and approval of five bridges in Jiangsu province, a scientific basis is provided for selection of large transportation channels, and the risk of bridge damage is effectively prevented.

The invention discloses a monitoring control system for static pressure pile machine construction. The monitoring control system comprises a central control system, a man-machine interaction screen display module, a static pressure pile machine operation module, a construction data acquisition module, a welding quality monitoring module, a pile foundation bearing capacity prediction module and a cloud data storage and presentation module. The invention further discloses an implementation method of the monitoring control system for static pressure pile machine construction. Through linkage of the central control system and the static pressure pile machine, efficient automation and accurate control of the construction process are achieved; in the construction process, the leveling and pile pressing operation of the pile clamping platform and the pile pressing platform can be regulated and controlled through construction data collected in real time, it is ensured that the prestressed concrete pile vertically enters the soil and reaches the designed pile pressing depth, and deviation is avoided; the welding quality monitoring module can monitor the welding quality in real time, and it is ensured that the construction quality meets the standard.

A post-tensioning anchor is configured to post-tension at least one tension steel element. The post-tensioning anchor includes a force transfer unit configured to transmit prestressing force into a surrounding concrete substrate and at least one steel member configured to resist an anchoring force by the at least one tension steel element on the force transfer unit. The force transfer unit is made of concrete.

The invention discloses a pressure relief and shock absorption method for a deep high-stress key pillar. (a) a top plate is arranged at the top of the ore pillar, four inclined kerfs are alternately arranged in a top plate area around the ore pillar, and the kerfs are symmetrically arranged in a cross shape; (b) eight anchor rod drill holes perpendicular to the top plate are formed in the interval area between the adjacent kerfs and the periphery of the ore pillar, perpendicular anchor rods are arranged in the anchor rod drill holes, and an orthogonal supporting network formed by the perpendicular anchor rods is formed; and (c) preferentially releasing the bending energy of the roof through the kerf, reducing the vertical load of the ore pillar, and meanwhile, forming a pressure arch effect by applying the prestress of the vertical anchor rod, thereby realizing space-time coupling support of the kerf and the anchor rod, and inhibiting roof separation and dynamic disturbance. The invention has the characteristics of excellent stress transfer, strong vibration suppression and excellent overall column stability.

The invention provides a beam string structure optimization method for reinforcing a large-span steel corridor, and belongs to the technical field of building construction.The method comprises the steps that firstly, a three-dimensional finite element model is established, the three-dimensional finite element model comprises an upper steel corridor, vertical supporting rods and inhaul cables, and boundary conditions and dead load and live load are set; performing nonlinear analysis to obtain an initial deflection value and a stress value, and judging whether reinforcement requirements are met or not. And if not, adjusting the length of the supporting rod and the prestress of the inhaul cable, and repeatedly analyzing and calculating until the requirements are met. Then, the structural deflection serves as a control parameter, the strain of the inhaul cable serves as a response parameter, cable force optimization calculation is conducted through an SAP2000CSiLoadOptimizer toolbox, and an optimized strain value of the inhaul cable is obtained. And finally, according to an optimization result, a final cable force optimization scheme is obtained through back-stepping, and specific process parameters of the beam string structure for reinforcing the large-span steel corridor are determined. The problem that an existing method cannot comprehensively reflect the nonlinear mechanical property of the structure is solved.

The invention belongs to the technical field of infrastructure structures and materials, and discloses an intrinsic self-prestress ECC material, a surface layer structure prepared from the intrinsic self-prestress ECC material and application of the intrinsic self-prestress ECC material. A low-dosage volume expansion component and a building and curing combined strategy are utilized, the bottleneck that self-stress and a construction window period are not coordinated is broken through, the highest free expansion deformation of the intrinsic self-prestress ECC material in the temperature and humidity curing process is controlled to range from 1500 mu epsilon to 10000 mu epsilon, the later-period service free volume deformation is kept to be 55% higher than the early-period highest free expansion deformation, and the service life of the intrinsic self-prestress ECC material is prolonged. And the dual requirements of intrinsic self-prestress and construction windows are innovatively met. The maintenance-free seamless ultrathin target of the ECC surface layer structure is achieved through high-performance intrinsic self-prestress and self-healing. The method is widely applied to the fields of ocean ultra-thin large-buoyancy floating bodies, road surfaces, bridge floors, airport runways, ultra-thin box culverts, concrete panels, pumped storage power station panels, anti-seepage panels, floor panels, canal linings, tunnel linings, old structure updating and repairing and the like.

The invention relates to a wall type-double column combined pier structure system, and belongs to the technical field of bridge engineering. The structure system mainly comprises a cover beam, a swinging pier, a replaceable corrugated steel web wall, a pier bottom energy dissipation device, a swinging steel base, a bearing platform, an unbonded prestressed tendon and the like. A pier bottom energy dissipation device is arranged on the lower portion of the swing pier and composed of energy dissipation steel bars, an outer wrapping steel plate, a bottom steel plate and fixing lug plates. A replaceable corrugated steel web wall is arranged between two piers, and an upper flange plate is directly installed on a cover beam through embedded high-strength bolts and fixed to a bearing platform through a swing steel base. Unbonded prestressed reinforcements penetrate through the center positions of the swinging bridge piers. According to the structural system, a collaborative energy consumption-graded swing mechanism of'corrugated steel web wall deformation energy consumption-corrugated steel web wall swing-pier swing and energy consumption 'is formed under the earthquake action, earthquake energy can be dissipated more effectively, structural residual deformation is reduced, and the structural shock resistance and function restorability are improved.

The present invention relates to the technical field of three-dimensional physical model tests with similar materials for deep underground engineering. Disclosed are an ultra-large bottom-openable three-dimensional loading device and a test method. The present invention provides a new ultra-large bottom-openable three-dimensional loading frame structure, which is suitable for automated bottom access of physical model specimens with dimensions of 5 m or larger and provides an optimal access mode. A prestressed composite structure is used for a vertical reaction frame, and a high-strength prestressed steel wire wound assembled structure composed of multiple longitudinal single-beam units with circumferential T-shaped dovetailed joints is used for a horizontal reaction frame, thus meeting high-rigidity design requirements of a three-dimensional loading device. The vertical reaction frame cooperates with a movable lifting beam for specimen bearing and is assisted by a reaction support base beam during a test to directly bear an applied load, thus ensuring equipment stability and operational precision during a loading test, and preventing lifting risks caused by unsynchronized positions of lifting cylinders. In regard to the problem of test data acquisition being affected by the abrupt rupture of a specimen impacting a loading frame test, a back-pressure buffering damping technique is applied to the lifting cylinders, ensuring the continuity of data acquisition.

The invention relates to a pipe pile grouting expanded head pile forming process special for a prestressed concrete water jet cutter and a pipe, and belongs to the field of pipe pile construction. The large-head concrete block is integrally connected with the lower end of the tubular pile body and is in an irregular shape, the tubular pile body sequentially comprises a pile cap, a plurality of pipe joints and an inverted-cone-shaped pile head from top to bottom, the tubular pile body is provided with at least one high-pressure water or cement paste channel in the axial direction of the tubular pile body, and the pile head is provided with a material water hole communicated with the high-pressure water or cement paste channel. During construction, even if a special stratum is encountered, the hard stratum is impacted through the high-pressure water jet cutter, and static pressure or hammering is matched, so that the problem that an existing pipe pile is difficult to descend is solved. When the designed elevation is reached, guniting is carried out through high-pressure water or a cement paste channel in the pipe pile body, and a sphere-like expanded head is formed at the bottom of the pipe pile; the bearing capacity of a single pile can be improved, settlement of the pile body is limited, local displacement of the pile body is eliminated, and the anti-floating effect of the pile body is achieved.

The invention discloses a variable-cross-section stacked box rigid frame aqueduct, a cantilever hanging basket and a prestress tensioning method in the field of prestressed concrete aqueducts, the transverse section of a water passing groove is a U-shaped section, and the U-shaped section of the water passing groove is far superior to a rectangular section in the aspects of water delivery flow conditions and flow passing capacity; a prestress continuous rigid frame structure form of a U-shaped water passing upper tank with a variable cross-section rectangular lower tank stacked upwards and a guide groove unified cross section and a two-system four-way prestress system are arranged, the concrete stress of the upstream face of the U-shaped water passing groove can be accurately and effectively controlled to be kept in a uniform compression state with a certain numerical value, and the anti-seepage and durability functions of the aqueduct are ensured. According to the tensioning method, the vertical steel beams and the U-shaped steel beams are partially tensioned firstly, so that the aqueduct web has certain vertical pressure stress, then longitudinal prestress is tensioned, the effect of the vertical steel beams and the U-shaped steel beams is prevented from being weakened by the longitudinal prestress, and pressure stress reserve of the upstream face of the U-shaped groove is guaranteed; the pouring hanging basket prevents the formwork from floating or shifting in the pouring process of the variable-thickness middle partition plate.

The invention discloses a tunnel portal section edge and front slope miniature steel pipe pile-anchor rod support tunnel entering construction method, relates to the technical field of tunnel construction, and aims to prevent and support the edge and front slope instability condition at a tunnel portal, a large number of anchoring type support structures are applied, and miniature steel pipe piles are convenient to construct, simple in structure and flexible in arrangement; however, the miniature steel pipe piles in engineering are prone to bending shear damage. The invention provides a tunnel portal section edge and front slope miniature steel pipe pile-anchor rod support tunnel entering construction method. The method comprises the steps that miniature steel pipe piles are constructed, and a top beam is poured; cutting the side slope; along with step-by-step excavation of the side slope, a waist beam and an anchor rod are constructed; advanced large pipe shed construction; and pile breaking and full-section excavation are carried out. The pre-stressed anchor rods and the miniature steel pipe piles are stressed together to resist landslide thrust, the slope reinforcing effect is enhanced, passive stress is changed into active stress, the structural stress is more reasonable, the engineering difficulty of pile breaking and hole entering is reduced, meanwhile, hole opening ground surface settlement and surrounding rock deformation are reduced, and the supporting and retaining slope does not collapse.

The invention discloses a simply-supported bridge external prestress supporting structure and an implementation method thereof, and relates to the technical field of bridge reinforcing engineering, the simply-supported bridge external prestress supporting structure comprises a bridge, a bridge abutment or a bridge pier, and further comprises an oblique supporting system, and the oblique supporting system comprises oblique supporting rods, hinge plates, anchoring plates, reinforcing rods and longitudinal tie bars; the hinged plate is anchored on a bridge abutment or a bridge pier, one end of each oblique supporting rod is supported at the bottom of the bridge, the other end of each oblique supporting rod is hinged to the hinged plate, the anchoring plate is a full-length steel plate and is anchored through the reinforcing and reinforcing rods driven into the bridge abutment or the bridge pier, and one reinforcing and reinforcing rod is arranged at the installation position of each oblique supporting rod. The longitudinal tie bars are connected with the anchoring plates and the inclined supporting rods, and the inclined supporting rods are tensioned to support the bridge. The bearing capacity of the bridge is increased at low cost through in-vitro reinforcement, so that the traffic safety under the condition that the traffic load of the bridge is increased for a short time is met, and meanwhile, the adverse effects of reinforcement and reconstruction on traffic are reduced.

The invention relates to the technical field of detection equipment, and particularly discloses prestressed steel strand performance detection equipment which comprises a machine body and an adjustable test bed installed at the top of the machine body through an inclination angle adjusting unit, and the top of the adjustable test bed is further provided with a continuous impact unit, a guide unit and two multistage clamping units which are in bilateral symmetry. The multi-stage clamping and fixing unit comprises a first-stage bending and clamping and fixing assembly, a bending control assembly and a second-stage circumferential clamping and fixing assembly. According to the invention, tensile strength detection and fatigue strength performance detection can be carried out when the steel strand is in a horizontal state, and tensile strength detection and fatigue strength performance detection can also be carried out when the steel strand is in an inclined state; according to the device, the first-stage bending and clamping assembly and the second-stage circumferential clamping assembly are matched with each other to carry out multi-stage clamping and fixing on the steel strand, so that multi-point and multi-direction clamping is realized, it is ensured that the steel strand is subjected to multi-direction uniform clamping force, and the steel strand is prevented from sliding in the tensile strength detection process.

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.