5692 results about "Pre stress" patented technology

A hearing-aid device and a method for transmitting sound through bone conduction are disclosed. The hearing-aid device comprises a piezoelectric-type actuator, housing and connector. The piezoelectric actuator is preferably a circular flextensional-type actuator mounted along its peripheral edge in a specifically designed circular structure of the housing. During operation, the bone-conduction transducer is placed against the mastoid area behind the ear of the patient. When the device is energized with an alternating electrical voltage, it flexes back and forth like a circular membrane sustained along its periphery and thus, vibrates as a consequence of the inverse piezoelectric effect. Due to the specific and unique designs proposed, these vibrations are directly transferred trough the human skin to the bone structure (the skull) and provide a means for the sound to be transmitted for patients with hearing malfunctions. The housing acts as a holder for the actuators, as a pre-stress application platform, and as a mass which tailors the frequency spectrum of the device. The apparatus exhibits a performance with a very flat response in the frequency spectrum 200 Hz to 10 kHz, which is a greater spectrum range than any other prior art devices disclosed for bone-conduction transduction which are typically limited to less than 4 kHz.

A pipette device has a coupling stud on which a pipette tip can be stuck in a slipping-on direction for coupling. The coupling stud has an adjustable pre-stress member that can be adjusted into a prestress state and a release state via an actuation device which is provided in the coupling stud. The pipette tip has an axial stop which interacts with a counter-stop of the coupling stud in an axial coupling position of the pipette tip. The prestress member in its prestress state acts upon a working surface of the stuck-on pipette tip having a surface component of the pipette tip, which extends radially inward, turned away from the stuck on direction, in such a way that it abuts sealingly on the working surface, and prestresses the pipette tip on the pipette unit into the axial coupling position. The prestress member, in its releasing state, substantially releases the working surface of the pipette tip (101).

A modular precast construction block system (10) with a wall subsystem (12) and a foundation subsystem (14). The wall subsystem (12) has a number of wall units (16) having cavities (40) and prestressed tension cables (58) cast therein. The wall units (16) are vertically stacked with alignment channels (42) in the top surface (28) of one wall unit (16) receiving the key portion in the bottom surface (30) of the wall unit (16) above, to form walls (26) with vertically aligned cavities (40). Threaded wall bars (24) and extension bars (74) are threaded through the cavities with a wall tensioning assembly (22) applying downward force on the wall units (16) and providing structural strength to the wall. The foundation subsystem (14) includes a variety of precast foundation members including T footing members (126), pier members (128), grade beam members (130), and column members (132). The T footing members (126) and grade beam members (130) include complementary angled pairs for creating angled and "T" joint foundation designs.

The invention belongs to the architecture field, which relates to an improvement with the foundation pile shape and the structure and the manufacturing method of the foundation pile and the foundation pile shaper in the architecture field, in particular the invention is a prestressing force high strength concrete square pile and the manufacturing method thereof and the shaping device. In the invention a square terminal plate is disposed on the two ends of the square pile, and the four sides of the terminal plate is provided with a groove, while the center is equipped with a circular hole, and between the circular hole and the four sides, a strain hole and a threading hole are arranged symmetrically; a stirrp of a reinforcement cage in a twist is welded on the principal reinforcement continuously, wherein the principal reinforcement is the steel strand or the steel bar; the concrete square pile and the four-side corners of the terminal plate are in a stress elimination arc, and the pile core is a columnar mid level outlet having the same diameter with the terminal plate central circular hole. The manufacturing method is characterized in that, the principal reinforcement has the fix ed length and blanking, and the stirrp of the reinforcement cage is welded in the seam welder with the high degree of mechanisation; the principal reinforcement is stretched in a group of a whole pile fixed value, wherein the stretching performance is good and the balance is consistent; the disposable high pressure has short shaping time, low energy consumption, high product grade; the die design meets with the shaping requirement of the shape, which is convenient to use.

The invention relates to a node connection device for a self-centering prestressed concrete frame. The node connection device is a device used for the connection between the beam and the column of a prefabricated reinforced concrete frame, and aims at improving energy consumption of a frame structure under seismic action and eliminating or reducing the residual deformation and damage of the frame structure. The connection device is characterized in that combined steel parts form an energy consuming device, two external friction steel plates (3) are arranged in the energy consuming device, are respectively and symmetrically arranged on the two sides of a column end reinforcing steel plate (4) and are connected with the column end reinforcing steel plate (4) into a whole body, two internal friction steel plates (8) are arranged between the two external friction steel plates (3), the upper end and the lower end of each internal friction steel plate (8) are respectively provided with a bean end reinforcing steel plate (5), friction discs (15) are respectively arranged between the two internal friction steel plates (8) and the two external friction steel plates (3), and friction-type high-strength bolts (12) penetrate through the external friction steel plates (3), the friction discs (15), the internal friction steel plates (8) and a prefabricated concrete beam (2) and connect all parts together.

A lift-type turbine comprising at least three blades at circumferentially spaced positions is supported for rotation about a vertical axis. Each blade has an airfoil shape to generate a torque about the axis responsive to wind across the blades. A support comprising cables under tension is connected between adjacent ones of the blades to extend generally circumferentially about the turbine. Accordingly a minimum number of parts form the structure of the blades while minimizing the drag produced during rotation thereof due to the support members lying in a common circumferential path. The tension of the support members can support the blades in a pre-stressed condition to optimize the shape and performance thereof.

Methods are disclosed for nondestructive testing and measuring the structural health of prestressed concrete structures, such as slabs, columns, girders, bridges, towers, elevated storage tanks, silos, cooling towers, wind power generation towers, liquefied gas storage tanks, nuclear power containment buildings, and the like. Measurements are made as the structure undergoes tensioning and detensioning operations. By measuring actual movements of cardinal points on the structure, in an absolute three-dimensional coordinate system, and comparing the measurements to a model—as tension on a tendon is changed—a margin of safety is assured. High accuracy measurements are made by electronic distance measurement (EDM) instruments over hundreds of meters, which yield coordinates of cardinal points with an uncertainty of the order of one part per million. The methods are proposed as possible alternatives to prior failures of post-tensioned concrete, including the Las Lomas Bridge, the Kapiolani Interchange On-Ramp, Turkey Point Unit 3 Nuclear Power Plant, and Crystal River Unit 3 Nuclear Power Plant. An extensive review of the most closely related prior arts is included.

A method for detecting breaks in a prestressed wire, rod or bar embedded in concrete surrounding a metal pipe is described. A remote field eddy current probe is traversed axially internally through the pipe so as to create an energy flow path externally of the pipe and a transformer coupling through the pipe, and generate a signal in a detector coil axially spaced from an exciter coil. As the exciter coil traverses the wire, rod or bar containing the break a signal change is generated, regardless of the radial position of the detector coil relative to the break.

The invention relates to an oscillatory drive having an output shaft that can be driven to perform a rotationally oscillating movement about its longitudinal axis and that comprises a free end, a holding fixture at the free end of the output shaft comprising a contact surface for attachment of a tool, a mounting section on the holding fixture, raised relative to the contact surface, that projects to the outside in the direction of the longitudinal axis and that is designed for form-locking connection with a mounting opening of a tool placed in contact with the contact surface, and having a securement for fixing the tool with its mounting opening on the holding fixture, the securement permitting the tool to yield in axial direction under the action of a torque, against a pre-stress, and the mounting section permitting the tool to rotate by a certain angle of rotation when the tool gives way axially.

The invention discloses a self-resetting pier column structural system with a built-in energy dissipation assembly and an implementing method for the self-resetting pier column structural system, and belongs to the field of bridge engineering. The self-resetting pier column structural system consists of a pier column, a bridge abutment, energy dissipation steel bars, non-adhesion prestressed steel bars with an elastic resetting function and an embedded part; in the novel pier column structural system capable of effectively reducing residual deformation and ensuring sufficient energy dissipation, a pier is connected with the bridge abutment through the energy dissipation steel bars and the non-adhesion prestressed steel bars. Compared with the conventional pier column node, the self-resetting pier column structural system has the advantages that: the non-adhesion prestressed steel bars are positioned in the axle center of the pier column, a self-resetting restoring force can be generated, and the problem that the conventional pier has large residual deformation under the action of an earthquake load and cannot serve people any longer can be solved well; the self-resetting pier column structural system is flexible in design and definite in structural stress; the pier is ensured to have sufficient strength and rigidity; and the self-resetting pier column structural system can be implemented by a prefabricating or on-site pouring method, is easy and convenient to construct, and is an advanced and practical novel pier column system.

Various high-strength microwave antenna assemblies are described herein. The microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. The antenna is a dipole antenna with the distal end of the radiating portion being tapered and terminating at a tip to allow for direct insertion into tissue. Antenna rigidity comes from placing distal and proximal radiating portions in a pre-stressed state, assembling them via threaded or overlapping joints, or fixedly attaching an inner conductor to the distal portion. The inner conductor is affixed to the distal portion by, e.g., welding, brazing, soldering, or by adhesives. A junction member made from a hard dielectric material, e.g., ceramic, can be placed between the two portions and can have uniform or non-uniform shapes to accommodate varying antenna designs. Electrical chokes may also be used to contain returning currents to the distal end of the antenna.

A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification is disclosed. The method includes preconditioning, pre-stressing, or pre-damaging fixed bioprosthetic tissue in a manner that mimics the damage associated with post-implant use, while, and/or subsequently applying a calcification mitigant such as a capping agent or a linking agent to the damaged tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the damage process (service stress) and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. The linking agent will act as an elastic reinforcement or shock-absorbing spring element in the tissue structure at the site of damage from the pre-stressing. In one method, tissue leaflets in assembled bioprosthetic heart valves are preconditioned by simulating actual flow conditions for a predetermined number of cycles, during or after which the valve is exposed to the capping agent.

A prestressed concrete frame includes prefabricated beam and pile and integrated by prestressed reinforce. The pile is of a length over 2-3 floors. The beam is of a length for one room. Reinforce inside the beam is of a length at least equal to the short beam line. Binding reinforce concentrated in the beam center zone is of a length at least equal to the short beam line. Structure reinforce is also applied into the beam. Joint reinforce is applied to the beam ends. A distance of 30-40mm left between the beam and pile. This frame is of good stability for earthquake.

A dynamic radial seal includes a rigid casing. The seal also includes an elastomeric casing positioned interior of and bonded to the rigid casing. The elastomeric casing has an axial spring member which extends radially inwardly from and axially along the rigid casing. The axial spring member includes a neck portion which extends from the elastomeric casing and a seal attachment portion that is attached to the neck portion and has a bonding surface. The seal also includes a pre-stressed fluoropolymer seal which has a bonding surface and a sealing surface. A bond joins the bonding surface of the pre-stressed fluoropolymer seal to the bonding surface of the seal attachment portion. The seal attachment portion of the spring member is operative to provide sealing contact of the fluoropolymer seal along the entirety of its sealing surface when engaged with a mating surface of a shaft. The fluoropolymer seal may be formed from PTFE and may include a groove or grooves formed in the sealing surface to enhance the sealing performance of the seal. The elastomeric casing may also incorporate a static seal or temporary dynamic seal to facilitate in-process testing or dirt exclusion, as well as one or more additional dirt exclusion features to protect the fluoropolymer seal from damage caused by environmental contaminants during the use of the seal.

The invention provides a finite element analysis method for the temperature action on a prestressed reinforced concrete continuous rigid frame bridge. The finite element analysis method is used for analyzing and calculating the stress and displacement distribution in the construction and finished bridge stage under different temperature gradient models, and provides references for designing and optimizing the prestressed reinforced concrete continuous rigid frame bridge. Through calculational analysis based on finite elements and the structural mechanics, the forward-calculation method is adopted for structural distortion and stress analysis according to the actual construction loading sequence of the bridge structure, so that the complex mechanics problem of box girder temperature self-stress, temperature secondary internal force in a prestressed reinforced concrete statically indeterminate structure and secondary stress of the temperature secondary internal force is solved easily, conveniently and efficiently, and the finite element analysis method has important practical value.

The invention belongs to the building support component technology field including the stress automatic control and monitoring as well as the structural safety, and relates to a steel tube supporting internal force automatic compensating and displacement controlling system. The system comprises an upper system, a PLC control system module and a field executive system. A steel support is arranged on a reinforced concrete diaphragm wall, a hydraulic jack is arranged on the steel support, and real time pressure monitoring values are fed back through a pressure sensor. The steel support and the hydraulic jack form a pre-stressed steel support structure, the hydraulic jack is connected with a hydraulic pump station through an oil circuit, and is connected with the PLC control system module through the pressure sensor, the hydraulic pump station is connected with the PLC control system module, and a PLC controlling device is connected with the upper system. Through auto-control software and a PLC control system, the automatic control to the axial force of the steel support is realized, thereby controlling the displacement and the settlement of the deep excavation supporting structure and the adjacent basic facilities.

The present invention is anchor support method and one kind of sectional hollow grouted anchor and has the features of first early strengthening locking and then grouting protection and prestressing. The sectional hollow grouted anchor consists of two sections including front solid rod and back hollow rod connected via connecting sleeve, the connecting sleeve has mortar blocking unit and hollow rod section has several centralizing units. There are side hole canal in the joint of the connecting sleeve and the hollow rod and hole canal in the support cushion for some pipe to pass through. The said anchor support method of the present invention is used for temporary and permanent fast support in both hard and weak rock formation conditions.

The invention discloses a deep well tunnel cable anchor rigid-flexible coupling support and surrounding rock overall reinforced support method which is characterized by firstly excavating a tunnel according to the shape of cross section of the tunnel, and spraying concrete on the surface of surrounding rocks of the cross section formed by excavation; adopting a steel bar mesh and a high-strength prestressed anchor for supporting the surrounding rocks of the tunnel in time; implementing high-strength prestressed anchor cables at the center and two spandrels at the top part of the tunnel; re-spraying the concrete on the surface of the surrounding rocks of the tunnel; mounting a grouting anchor pipe on a top plate and two side surrounding rocks of the tunnel after the tunnel is excavated for 15-20d, and injecting cement slurry into fracture regions of the surrounding rocks of the tunnel; excavating a baseplate of the tunnel after the tunnel is excavated for 25-30d, mounting the grouting anchor pipe, injecting cement slurry liquid into a rock layer of the baseplate; and finally using the concrete to backfill the baseplate of the tunnel flat. The method can solve the problems of large deformation of the deep well tunnel and serious floor heave, avoid the repair work of the tunnel and have significant economic benefits.

The invention relates to a cold forging technology for a gear shaft; the cold forging technology is characterized in that a new technology of the cold forging forming of the inside and outside and split flow forging, a volume split flow space is arranged between the gear shaft diameter and a concave die, the metal flow resistance is reduced and the unit extruding force carried by the die is lowered by split flow; high-strength die steel and split structure are adopted to produce a gear hole forming die; the concave die is produced by adopting three-layer sleeve prestressed structure so as to improve the compression resistance of the die; a punch is made from an alloy steel material and used for the cold forging and precision forming of a complex gear form blind hole, which improves the forming quality and production efficiency of the gear hole, and lowers the consumption of the raw materials markedly. The cold forging technology of the invention has the advantages of achieving the smooth forming of the gear form blind hole, improving the production efficiency greatly, and improving the quality of the gear hole and the qualification rate of the product markedly.

The invention discloses a damage-controllable self-resetting section prefabricated assembled steel pipe concrete bridge pier and a manufacturing method thereof, and belongs to the field of bridge engineering. An exposed node connecting piece consists of a foot plate, anchor bolts, end connecting plates and buckling restraining sleeves. A connecting plate is mounted between prefabricated steel pipe concrete sections through high-strength bolts; the exposed node connecting piece is connected with each of a cover beam and a bearing platform by utilizing the anchor bolts, and is connected with a prefabricated steel pipe concrete section through the high-strength bolts relying on the end connecting plates. A pre-stressed tendon penetrates through a section prefabricated steel pipe concrete pier; the two ends of the pre-stressed tendon are respectively anchored to the interiors of the bearing platform and the cover beam by using anchorage devices. The energy consumption-controllable self-resetting section prefabricated assembled steel pipe concrete bridge pier disclosed by the invention has the characteristics of small post-seismic residual displacement, high energy consumption capacity, controllable energy consumption, high assembling degree, convenience and quickness in construction process, greenness, high efficiency, energy conservation, environment friendliness, easiness in factory production, convenience and quickness in construction, and the like; the construction period of the pier can be remarkably shortened.

This invention is a prestressed concrete pole and its construction method. The pole is of a conicity at 1:75, with holes for cables. It can be a single pole or sectional fabricated. The pole is made by reinforce bar cage centrifugal casting. The reinforce bar cage is composed by vertical main bars and normal bars fixed on supporting and positioning loops, and binding outside by helix wire. Two end plates are installed to the pole ends to fix the mail bars. After installed the end plates and before centrifugal casting, pull the plates with 1000-1900KN power, and steaming the concrete to grade over C60, then loose the power. In case of sectional fabricated, the sections are connected to each other through bolts.

The invention discloses an irregular foundation pit support and a construction method; the irregular foundation pit support is characterized in that: an inner support adopts a way that a girt is supported on an arched beam, the arched beam is arranged in the irregular foundation pit, and a cross beam is arranged in the arched beam to enhance lateral rigidity. When the arched beam is less than 15m,four anchored piles are arranged below the arched beam; when the arched beam is more than or equal to 15m, eight anchored piles are arranged below the arched beam. And the anchored piles are uniformly distributed by surrounding the arched beam. The anchored pile and a foundation pit support pile are expansion-head bored piles, the girt is arranged on the bored piles, and the girt is connected with the arched beam by a preload stress steel pipe. Two to three rows of inner supports are adopted, when two rows of the inner supports are adopted, a first row is arranged at the top part of a soldierpile, a second row is arranged in the middle part of the soldier pile and a third row is arranged at the position of 2/3 the middle part of the soldier pile. The irregular foundation pit support hassimple structure, clear stress route, low lost of engineering construction and convenient construction; in addition, the supporting structure has small deformation, and has less effect on the surrounding buildings.

The invention relates to a steel frame precast prestressed beam column joint with a post-earthquake recovering function. The joint comprises a steel frame column, a short beam section, a beam column connection device and an energy consumption device, wherein the steel frame column comprises a steel column, a column reinforced rib and a column reinforced plate; the short beam section comprises a short beam section web, a short beam section flange and a short beam section flange reinforced plate; the beam column connection device comprises a short beam section web reinforced rib, a prestressed cable and a beam end top plate; the energy consumption device comprises two channel steels and a high-strength bolt; and the two short beams are integrally connected with the column in a factory through a tension prestressed cable and two short beam section web reinforced ribs. When the earthquake action achieves a certain degree, the contact surface of the beam and the column is opened; the high-strength bolt is in friction energy dissipation so as to avoid destroying main components, such as beams and columns After the earthquake, the beams can be recovered to the former vertical position under the action of the prestress.

The invention discloses a method for detecting the strain/stress of a pile body by a prestress pipe pile field static load test, comprising the following steps of: pre-burying a strain gauge in a prestress pipe pile; leading out a lead in the piling process of the prestress pipe pile; before producing the prestress pipe pile, pre-burying an additional reinforcing steel bar with the stress gauge in a reinforcing cage, leading the lead connected with the stress gauge to a near-end part of the steel reinforcing bar of the reinforcing cage along the additional steel reinforcing bar and fixing the lead, placing the reinforcing cage in which the additional reinforcing steel bar with the stress gauge is buried into a steel die produced by the prestress pipe pile and producing the prestress pipe pile according to a normal production process except high-pressure steam curing; and binding all leads of each pipe pile during piling on the fixed device at the position of the section of the pipe pile, which is close to the end part, pulling all leads of next section of pile during pile connection to the fixed device of the last section of pile from a pile cavity and fixing and leading out the leads from the end head at the top of the pile, on which a groove opening is arranged in advance. The invention is applied to the field of civil construction engineering, can be simply and conveniently operated and has high precision and favorable economy.

Methods of using a guide catheter employ a retractable inner guide movably disposed within an open lumen of a splittable outer guide. The outer guide includes a longitudinal pre-stress line extending from distal to proximal ends. The inner guide includes an open lumen adapted to receive a payload. The inner guide is translatable and rotatable relative to the outer guide. The guide catheter further includes a proximally attached guide handle which is separable into at least two sections. Separation of the guide handle splits the proximal end of the outer guide. Proximal outer guide retraction continues the splitting of the outer guide along the longitudinal pre-stress line.

The invention relates to the technical field of fabricated concrete frame structures, and discloses a pre-stressing-force fabricated concrete-frame-joint connecting structure and a construction method thereof. The pre-stressing-force fabricated concrete-frame-joint connecting structure comprises a prefabricated concrete column, a prefabricated concrete superposed beam, a composite floor slab, a post-tensioned pre-stressing tendon, an anti-bending and energy-consuming reinforcing steel bar and a shear-resistant and high-strength reinforcing steel bar, wherein the post-tensioned pre-stressing tendon, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are connected with the prefabricated concrete column and the prefabricated concrete superposed beam. A beam post-pour layer of the prefabricated concrete superposed beam and a slab post-pour layer of the composite floor slab are poured integrally, the inner portion of a beam column seam between the prefabricated concrete superposed beam and the prefabricated concrete column is filled with high-strength crack-pouring binding materials, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are laid in the beam post-pour layer of the upper portion of the prefabricated concrete superposed beam, and the anti-bending and energy-consuming reinforcing steel bar is located above the shear-resistant and high-strength reinforcing steel bar. According to the pre-stressing-force fabricated concrete-frame-joint connecting structure and the construction method thereof, efficient construction can be achieved, the anti-seismic property and the progressive-collapse-resistant capability are good, and post-earthquake repairing is facilitated.

A method for constructing pipe piles while drilling for building or bridge foundations. The construction steps are to cover high-strength prestressed concrete pipes or steel pipes with drill pipes on the ground first, and install impactors and reaming retractable drill bits at the front ends of the drill pipes. , Follow the pipe while drilling, follow the pipe retaining wall, drill to the design elevation, stop drilling, withdraw from the reaming to shrink the drill bit, use the mud pump to clean the mud and sediment, pour concrete into the pipe, and simultaneously inject pressure grout to the outside of the pipe wall , stop when concrete and grout reach the ground; the object of the invention is to propose a construction method with fast construction speed, reliable quality, less material consumption, high bearing capacity of piles, mechanized operation, and environmental protection. In the construction method of bored cast-in-place piles, the use of mud retaining walls pollutes the environment, the hole is easy to collapse during the drilling process, the quality of concrete pouring is unstable, and the prestressed pipe piles are easy to cause the soil to rise. The strength of the pile body constructed by the invention is high. , There is no sediment at the bottom of the pile, and the pile end is completely rock-socketed, which can reach more than 2 times the bearing capacity of the same diameter bored pile.

The invention involves a kind of data organization project area of technology to guard against the flexure to consume energy the steel plate shearing force wall. Its characteristic causes to state the shearing force wall to inlay the steel plate and two sides periphery concrete lap by in is composed; In states inlays the steel plate to use the low yield point high ductility steel products or the high strength high ductility steel products; States the periphery concrete lap to use the common concrete slab; States the edge component is composed by the marginal beam and the edge column; In states inlays the steel plate with to state between the concrete lap through to penetrate three blocks the bolts or the pre-stressed bold fastening, in states on the concrete lap to open the ellipse hole in order to the bolt passed through also has the enough slipping space; In states the concrete lap to open the hole site with to bury the trough section to give strengthens. And is strengthening the channel steel the corresponding position to open oval hole. The invention provides guards against the flexure steel plate shearing force wall is the high-rise construction structure or other structures a kind of new anti- lateral force components, it has the earthquake resistance performance well, the ductility is high, consumes energy stagnates winds full and so on the characteristic, is a kind of superior earthquake resistance consumes energy the component.

The invention concerns a method of erecting a pylon of prestressed concrete finished parts and an apparatus for advantageously carrying out the method. In order to at least reduce the problems present in the state of the art when erecting a pylon, there is provided a funnel-shaped apparatus 8 for guiding a tensioning wire, the smaller cross-section 11 thereof being substantially the same as that of the jacket tube 7. There is further provided a seal 20 for producing a pressure-tight transition between two mutually superposed segments 4, 6, wherein the height of the seal 20 substantially corresponds to the intended spacing of the segments. Also provided is a prestressed concrete finished part 4, 6 in which the apparatus 8 according to the invention is integrated. Finally there is provided a method in which epoxy resin is used as a composite joining material 34 between two segments.

The invention discloses an external prestressing construction method for box bridge maintenance, which is characterized in that: 1). The position of an anchor block, a redirector and a shock absorber are decided according to external cable arranging mode for external prestressing; 2). The installation of the anchor block: 2.1). concrete base surface processing; 2.2). hole drilling, hole cleaning and reinforcing bar planting; 2.3). the installation of steel-bonded steel plate: the anchor block comprises a steel-bonded steel plate, a connecting plate and a stiffening plate; all anchor bolts are penetrated through a corresponding fixing hole on the steel-bonded steel plate; 2.4). the installation of other steel plates for the anchor block; the connecting plate is welded with the steel-bonded steel plate, the stiffening plate is welded with the steel-bonded steel plate and is provided with a through hole for external cable; 2.5). glue pouring for the steel-bonded steel plate: glue pouring is made between the steel-bonded steel plate and the concrete base surface for the anchor block; 3). Horizontal partition wall perforation; 4). The installation of a redirecting support and a damping support; 5). The installation of the redirector; 6). Penetrating and tension of prestressing steel strand; 7). The installation of the shock absorber. The invention has the advantages of convenient construction, flexibility and stronger reliability.