CN100529264C - Method of applying prestress and connecting means used therein and prestressed concrete beam therefrom - Google Patents
Method of applying prestress and connecting means used therein and prestressed concrete beam therefrom Download PDFInfo
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- CN100529264C CN100529264C CNB2005800050300A CN200580005030A CN100529264C CN 100529264 C CN100529264 C CN 100529264C CN B2005800050300 A CNB2005800050300 A CN B2005800050300A CN 200580005030 A CN200580005030 A CN 200580005030A CN 100529264 C CN100529264 C CN 100529264C
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- tensional
- tensional element
- compressed member
- concrete
- anchoring device
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01K—ANIMAL HUSBANDRY; CARE OF BIRDS, FISHES, INSECTS; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
- A01K93/00—Floats for angling, with or without signalling devices
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C3/00—Structural elongated elements designed for load-supporting
- E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
- E04C3/20—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members
- E04C3/26—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members prestressed
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D2/00—Bridges characterised by the cross-section of their bearing spanning structure
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
- E04C5/08—Members specially adapted to be used in prestressed constructions
- E04C5/12—Anchoring devices
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/12—Mounting of reinforcing inserts; Prestressing
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
- E01D2101/00—Material constitution of bridges
- E01D2101/20—Concrete, stone or stone-like material
- E01D2101/24—Concrete
- E01D2101/26—Concrete reinforced
- E01D2101/28—Concrete reinforced prestressed
Abstract
A method of applying , prestress to a structural member resisting deflection such as a beam or a girder. used for a structure or a bridge by a post-tensioning method to apply the optimum prestress to the structural member resisting deflection by applying not a compressive force but deflection to the structural member and to apply a large moment with a low tensile force by using a principle that not a distance between the center of the cross-section of the structural member and a tension member but a distance between a compression member and the tension member is eccentric. Using this method, a prestressed concrete beam includes: a tension member of high strength passing the tension zone of the structural member subject to deflection in a state of the tension member is not attached to the structural through a sheath pipe; compression members passing the compression zone; and an anchoring device for connecting the compression members and the tension member, so that the compression members of high strength, not the structural member,. receive a compressive force, a reaction force of a tensile force, by tensioning and anchoring the tension member, supported by the anchoring device. By ;using such a method alone or using such a method in combination with the conventional prestressing method using only tension members, compressed prestress in the tension zone and tensile prestress in the compression zone can be easily and right applied to a critical section of the structural member subject to deflection.
Description
Technical field
The present invention relates to a kind ofly apply prestressing force so that increase the method for weight capacity of the structural element of the opposing moment of flexure be used for beam or purlin, particularly, relate to the height that a kind of basis is lowered and the prestressed amount that applies of increase and in the tensile region, apply compression prestress and in the pressure zone of structural element, apply the prestressed method that stretches, and be used for anchoring device wherein.
Background technology
Generally speaking, for various buildings, usually structural iron and concrete are used as the structural element of resisting moment of flexure.Concrete is used the most widely, because it is cheap and be easy to form with different shape, and it provides the protection of avoiding vibrating.Concrete has very big compressive strength, but tensile strength is very little.Therefore, be subjected to not only producing compression but also produce the stretching deflection building need with the relevant reinforcement that stretches.For this reason, the design reinforced concrete beam, make reinforcement bar resist the stretching in the tensile region, and with concrete or prestressed concrete beam (hereinafter, be called " PSC beam ") intensity irrelevant, thereby because the compression prestress that applies in advance in the tensile region makes that the concrete in the tensile region is utilized effectively.
Because most of PSC buildings and PSC beam use the tensional element of being made by high strength cast iron, so they have the coefficient of elasticity similar to normally used steel, but the normally used steel of its strength ratio is big four to six times, thereby they are very suitable for being used in combination with concrete.Because tensional element has the high strength of relative resilient coefficient, promptly has very high ratio of elongation, so will follow very large distortion so that farthest utilize intensity.Therefore, tensional element is not suitable for being applied directly to building and supports dynamic loading.Yet if tensional element is applied prestressed material with acting on to concrete, it is very useful and has following advantage that promptly because long-term plastic strain such as drying are shunk or concrete creep, the internal stress loss is minimum.That is, when at tensional element with the distortion of very big deflection and have when being embedded into tensional element in the tensile region under the situation of tensile stress, pressure is applied to concrete as reaction force.Be applied to concrete compression prestress and make the concrete that is in the tensile region be subjected to tensile load, thereby increase rigidity of support.
Simultaneously, constantly make the trial that the PSC beam is used for low-rise building and big span according to the variation of market environment.In view of the above, only applying compression prestress in concrete tensile region is not enough sometimes.In order to reduce because the weight of load such as building itself or external force and the variable quantity of the stress that in the tensile region, produces, trial is by reducing to pressure zone minimum and making the tensile region reach maximum, near Position Design one neutral axis of tensile region, this neutral axis is the boundary face between pressure zone and the tensile region more.Yet, because in pressure zone, applied excessive compressive stress, so this design has caused some problems.In addition, when carrying out repetition prestressing, caused similar problem according to the increase of the load on all stages of structure.About using the prestressing method of tensional element, it is relatively easy applying pressure zone in the tensile region, is very difficult relatively and apply stretching prestressing force in compression prestress.And, can be by increasing eccentric throw, on the contrary a spot of pulling force is applied to concrete in the pressure zone with eccentric direction, but the restriction of maximum eccentricity is arranged, wherein eccentric throw is the distance between cross-section center and the tensional element.That is, as shown in Figure 6, the place that shows according to the tensional element grappling is applied to the power of structural element and shows bending moment diagram, and the power that is applied to structural element is according to how arranging that tensional element and tensional element present position change.Particularly, the moment of flexure that is applied to certain cross section changes according to the position of tensional element in the cross section and the size of pulling force.
Here, by take advantage of eccentric throw (being the distance between tensional element and the cross section neutral axis) to obtain the size of moment of flexure with pulling force.Therefore,, member should be increased, that is, height should be increased in order to increase eccentric throw.Yet,, increase the pulling force of tensional element in order to keep this height to a certain extent.In this case, moment of flexure increases, but the pressure bigger than required pressure is applied to member, causes the at first ruined problem of pressure zone of member.
As mentioned above, apply compression prestress and have restriction in the tensile region of structural element, this is because only can obtain to compensate the effect of tensile strength deficiency, thereby has restriction aspect the efficient of utilizing prestressing design cross section.Therefore, in order to support very large external force, must be not only by applying eccentricity pressure but also by in the cross section of structural element, exerting pressure simultaneously and pulling force with compressed member and tensional element, apply (that is, applying in advance) moment of flexure in advance to the cross section of structural element along the direction opposite with the moment of flexure of external force generation.
Openly announce to disclose among the No.10-220009 for the Japan Patent of the method for grappling compression PC steel pole " promote and " at exercise question and apply the prestressed technology of stretching in the pressure zone of compressed member at structural element by using.Promptly, as shown in Figure 7, method is as follows: the embedding mould that is formed from steel is to penetrate the top of PSC beam, the top of PSC beam is pressure zone, so that pressure is applied to high-intensity compressed member, near the two ends of PSC beam, form excision portion then, then compressed member 13 is anchored to punching block, and rely on the compression jack 30 that both sides form compressed member 13 is shifted onto in the mould that is formed from steel at the upper surface place.In addition, if the prestressing process is finished, then fill excision portion with the space between cement paste filling sleeve pipe and the compressed member with concrete or mortar.
Promptly, by straining tensional element 12 and grappling tensional element subsequently in advance, compression prestress is applied to the bottom of PSC beam, this bottom is the structural element 10 that is subjected to by the deflection of moment of flexure generation, and, stretching prestressing force is applied to the top of PSC beam by the position that compressed member 13 does not reach work excision portion 31 will be set to through the compressed member 13 of grappling excision portion 32.In addition, be put in the work excision portion 31 by compressing jack 30, concrete support portion pushes compressed member 13 at the rear portion, then the fixing compressed member 13 of pressurized of the set bolt by tightening grappling excision portion 32 places.Because the end of compressed member 13 places the concrete between work excision portion 31 and the grappling excision portion 32, so apply power indirectly by inserting independent steel bar.
Yet this technology not only has low constructivity and economy, and the restriction that possesses skills, that is, stress raisers are on the part of the reaction force that applies the compression jack and on the part of grappling compressed member.Generally speaking, stress raisers are on the anchor portion of tensional element but mainly produce compressive stress, and therefore suitable reinforcement can address this problem.Yet, obtaining suitable reinforcement to prevent that fully the crack from being very difficult, this is because can produce tensile stress when the grappling compressed member.
In addition, also cause problem owing to work must be carried out at the upper surface of PSC beam.Trend according to effective design cross section, the high-strength material that will be used for prestressing is designed to withstand bigger static load, and concrete is designed to support and withstand changing load (live loads), this needs to prevent the vibration that caused by moment of flexure or the rigid nature of deflection.In order to realize these targets, should except the weight of PSC beam itself, after the static load that produces in addition such as flaggy (slab), carry out the prestressing process.Yet, in conventional art, if the structure flaggy owing to be not provided for enough working regions of prestressing process, is very difficult so carry out the work of prestressing.
In addition, because the process of the work of tension tensional element and compression compressed member is carried out separately, so process is complicated, each stage needs according to structure are analyzed, design tensional element and compressed member anchor portion separately, and this process need respectively to stretch jack and compression jack.
Summary of the invention
Thereby, the purpose of this invention is to provide a kind of device that applies prestressed method and a kind of this method of application is provided, the stretching by carrying out tensional element simultaneously and the compression of compressed member, this device can be by simple tension process, applies deflection in the situation lower edge direction opposite with load that does not apply axial force to the structural element that is subjected to deflection.
Another object of the present invention is to make when each other reaction force of the compressed member that connects by anchoring device and tensional element reception, and the independent reinforcement of anchor portion needn't be provided to structural element.
In order to realize above-mentioned target, a kind of prestressed method that applies is provided, comprising: in the tensile region of structural element, tensional element is set so that tensional element is not linked on the structural element and make tensional element be exposed to the end of structural element along its longitudinal direction; In the pressure zone of structural element, compressed member is set so that compressed member is not linked structural element along its longitudinal direction; The anchoring device that will be used to compressed member is linked to each other with tensional element is fixedly mounted in compressed member, pass the tensional element of anchoring device with tension, wherein the pulling force opposite reaction with tensional element is applied to compressed member as pressure by anchoring device, makes simultaneously to apply pulling force and exert pressure to compressed member to tensional element.That is, under the situation about influencing in the anchor station that is not subjected to tensional element and compressed member, according to the layout of tensional element and compressed member, structural element receives upward force and receives downward force in the end at the center.At this moment, can be anchored thereon anchoring device, and in anchoring device, relative their the own balances of power that produce from tensional element and compressed member with forming compressed member and tensional element.
Here, preferably, this method also comprises by the space between prearranged and tensional element, compressed member and the structural element and links to each other and be exposed to outside grouting hose injection grouting agent, make the grouting agent hardening, after the hardening step, discharge anchoring device then, so that can use this anchoring device repeatedly.
Simultaneously, the invention provides a kind of being used for and apply prestressed anchoring device to the structural element that is provided with tensional element and compressed member, comprise: main body with first hole and second hole, the tensional element of bunchy passes first hole, second hole is formed on the both sides in first hole of tensional element, and compressed member passes second hole; Set bolt, the compressed member that is used for passing main body is fixed on the front and rear of main body; Have the form anchor in a plurality of the 3rd holes and close first hole, tensional element can pass the 3rd hole one by one; Be used for behind the tension tensional element, tensional element being anchored to the wedge (wedge) in the 3rd hole of form anchor, wherein reaction force is delivered to form anchor and main body in the tension process of tensional element, be delivered to compressed member with the reaction force that transmits by set bolt, thereby exert pressure.By such mode, do not apply axial force to structural element, layout according to compressed member and tensional element produces deflection, and structural element does not need to be used for the independent reinforcement of grappling tensional element and compressed member, and can apply very big moment of flexure to structural element by a tension process.
In addition,, also provide a kind of prestressed concrete beam, having comprised: concrete in order to realize above-mentioned target; Compressed member, it is imbedded along the longitudinal direction in the described concrete top by means of sleeve pipe and makes compressed member not link on the structural element; Imbed the tensional element with sweep in the described concrete lower part along the longitudinal direction, its center is towards last; Be used for tensional element and compressed member are fixed on the anchoring device of described concrete end, wherein tensional element passes anchoring device and is exposed to the outside, compressed member is fixed to anchoring device, and by drawing tensional element, exerts pressure to compressed member by anchoring device.
In addition, if will aspect stretching, have the material of weakness such as the material that concrete is used for structural element, then when the direction opposite with the deflection that is caused by load applies prestressing force, wherein said load for example is the weight of structural element or is applied to external force on it, can strengthen this intensity by applying prestressing force by using conventional prestressing method together at the material that has weakness aspect the stretching.
For the prestressed concrete beam continuous with another prestressed concrete beam is installed, one end of the described sleeve pipe on the described concrete of process top does not reach the end of described prestressed concrete beam but is installed to till the position, in this position, the end of described sleeve pipe separates a preset distance with the end of described prestressed concrete beam, and the compressed member that is arranged in the described sleeve pipe exposes the length the same with the length of being scheduled to and is embedded in the described concrete from an end of described sleeve pipe.
Description of drawings
Fig. 1 illustrate the power that when by method of the present invention tension tensional element, is applied to structural element and with the corresponding bending moment diagram of this power;
The end that Fig. 2 is illustrated in compressed member is linked under the situation on the structural element and be applied to the power of structural element and the bending moment diagram that is caused by this power when being strained tensional element for continuity;
Fig. 3 is a front elevation drawing, and prestressed concrete beam according to an embodiment of the invention is shown;
Fig. 4 is the lateral view of Fig. 3;
Fig. 5 illustrates an embodiment of the anchoring device that is fixed to compressed member that is used for the grappling tensional element with different directions;
Fig. 6 illustrates power and the bending moment diagram that is applied to structural element according to the prestressing method of routine according to the anchor station of tensional element;
Fig. 7 illustrates and is used to apply the prestressed conventional configurations that stretches; With
Fig. 8 is illustrated in the comparison between the stress that causes on the structural element according to conventional prestressing method and one embodiment of the invention.
The specific embodiment
Hereinafter, with preferred embodiments of the present invention will be described in detail with reference to the annexed drawings.
As shown in Fig. 1 to 4, applying prestressed method according to an embodiment of the invention comprises: the tensional element 12 that will have the part of being bent downwardly in structural element 10 bottoms sinks in the sleeve pipe 11, the bottom of structural element 10 is promptly along the tensile region of structural element 10 longitudinal directions, with tensional element 12 is set makes it not link on the structural element 10 and make tensional element 12 be exposed to the end of structural element 10 simultaneously; Top at structural element 10 is sunk to compressed member 13 in the sleeve pipe 11, the top of structural element 10 is promptly along the pressure zone of structural element 10 longitudinal directions, with compressed member 13 is set it is not linked on the structural element 10, and make compressed member 13 be exposed to the end of structural element 10 simultaneously; Install regularly at compressed member 13 and to be used to anchoring device 20 that tensional element 12 is linked to each other with compressed member 13, and the tensional element 12 of anchoring device 20 is passed in tension; And link to each other and be exposed to outside grouting hose injection grouting agent by the space between prearranged and tensional element 12, compressed member 13 and the structural element 10, make the grouting agent hardening, unclamp anchoring device 20 then.
Here, tensional element 12 and compressed member 13 are made by high-strength material, and they are lowered in the sleeve pipe 11 and are fixed on structural element 10 inside, make tensional element 12 and compressed member 13 can apply pulling force and pressure, and do not link on the structural element 10.
Anchoring device 20 is exposed to the end of the structural element 10 that is subjected to deflection, and serves as the anchoring device of tensional element 12 and compressed member 13.The power that is applied to anchoring device 20 by tensional element 12 and compressed member 13 is balance.The compressed member 13 that will be exposed to the end by fastening devices such as set bolt 21 is fixed firmly to anchoring device 20.As for tensional element 12, use some thick wires of the tensional element that can be bent that get to allow various layouts.Tensional element 12 passes anchoring device 20 one by one and is passed in the hole of making in the form anchor 22.The tensional element 12 that passes form anchor 22 by the tension of general take-up device is with prestressing, and anchors to form anchor 22 with the tensional element 12 that wedge 23 will be passed form anchor 22.
Because tension device supports form anchor 22 and tension tensional element 12, so be delivered to compressed member 13 with the pulling force opposite reaction by anchoring device 20 and set bolt 21, and the pressure that equates with the pulling force that is applied to tensional element acts on the compressed member 13.In the tension process, it is shorter that compressed member becomes on length, thereby anchoring device preferably is mounted to structural element and separates fully.Can carry out the tension process according to the increase of load in addition.After finishing last tension process,, thereby compressed member and tensional element are linked on the structural element by grouting hose 24 injection grouting agents.
Fig. 1 represent when straining tensional element, to be applied to according to the present invention structural element power and with the corresponding bending moment diagram of this power.Compressed member 13 and tensional element 12 are arranged to not link the structural element 10 that is subjected to deflection, and both are exposed to the end, and anchor to anchoring device 20 with equilibrium state.Although use separator to prevent buckling (bucking) or obtain supporting condition at interval with certain by other method, can not allow the degree of freedom of arranging, this is because compressed member 13 should be able to be resisted minimum deflection.Thereby preferably, compressed member 13 is almost arranged point-blank.The layout of control tensional element 12 is convenient to control the moment of flexure that is applied on the respective cross section.
Simultaneously, on two spans, form structural element and pillar continuously or integrally, need apply prestressing force so that continuous part can be resisted the hogging moment that is caused by load in order to make the structural element that is subjected to deflection.Fig. 2 shows under an end of compressed member is linked situation on the structural element and be applied to the power of structural element and the bending moment diagram that is caused by this power when straining tensional element for continuity.Figure 2 illustrates a span of structural element continuous on two spans, and presstressed reinforcing steel (tendon) has the layout of symmetry based on continuity point (right-hand member among Fig. 2).
The enforcement of this continuous prestressed girder comprises: arrange a plurality of beams, the sleeve pipe that is embedded in that wherein has the U-shaped sweep is exposed to the two ends of beam, puts beam and connects the sleeve pipe that exposes along continuous string pendulum then; Make beam continuous by placing concrete, then the steel wire insertion of tensional element is imbedded in the sleeve pipe of a plurality of beams continuously at the connecting portion of beam; And tension tensional element.That is,,, thereby realize the connecting portion of higher-strength so the sweep of tensional element is applied to the connecting portion of prestressed girder with pressure because the tensional element with U-shaped sweep is embedded in the prestressed girder and is subjected to pulling force.
More specifically, with continuous structure tensional element 12 is set continuously.Compressed member 13 is set to them separates the point of certain distance, and link on the structural element 10 their end with continuity point.According to the material and the shape of structural element, the various methods of compressed member being linked or anchored to structural element can be arranged.Yet under the situation of PSC beam, can expose in the end that will be linked concrete compressed member 13 has certain length so that easily compressed member 13 is not linked structural element by placing concrete under the situation of being surrounded by sleeve pipe.In this case, if support the tensional element 12 that is exposed to the end and with tensional element 12 tensions, then structural element stands moment of flexure and is under pressure simultaneously near the continuity point relative with the center of span by anchoring device 20.Distance between compressed member 13 and the tensional element 12 is eccentric at the center of span.Yet, do not having near the continuity point of compressed member, be eccentric and tensional element passes through above cross-section center in the distance between cross-section center and the tensional element 12 as shown in phantom in FIG..Thereby, the moment of flexure opposite with the moment of flexure of the centre of span appears.
The material and the concrete that is used most widely for prestressed girder of the intensity that prestressing method according to an embodiment of the invention correctly can be applied to have similar opposing stretching and compress.Thereby, more effectively be when said method is applied to prestressed concrete beam, also to use the conventional prestressing method of only using tensional element so that compensation has the character of the material of weakness aspect stretching.Especially, at the flexible member of the bridge that is used for standing huge changing load such as traffic load and building own wt, no matter structural element stands any load, and the stress on the edge of a wing, upper and lower of structural element should not surpass the tensile stress that allows.Thereby it is required that another tensional element except the compressed member that matches with a tensional element only applies moment of flexure.Fig. 3 and 4 is illustrated in the front elevation drawing and the lateral view of the prestressed concrete beam that proposes in the one embodiment of the invention.Compressed member 13 is embedded in the top of PSC beam 10, and tensional element 12 is embedded in the bottom of PSC beam 10.Some compressed members 13 and tensional element 12 are mounted to by means of sleeve pipe and do not link PSC beam 10, and are exposed to the end of PSC beam 10 and are connected with each other by anchoring device 20.Other tensional element that does not link to each other with compressed member is linked the PSC beam under the situation by the tension of tension method in advance, or under the situation of not linking the PSC beam, be embedded in by means of sleeve pipe, pass second anchoring device 33 that is installed in the PSC beam end and be exposed to the outside so that can be by post-tensioned method tension tensional element.
When the material of structural element had weakness aspect stretching as concrete, preferably the pulling force by making tensional element to realize compressing prestressing greater than the pressure of compressed member biglyyer.
Hereinafter, with the operating principle of describing about one embodiment of the invention.
According to prestressing method of the present invention, compressed member and high-intensity tensional element all are used for the prestressing member.Because in the recuperability each other of structural element end, compressed member and tensional element are under pressure and pulling force.Suppose that the structural element horizontal positioned is to receive vertical load, then structural element is subjected to power up or down according to the layout of compressed member and tensional element, but be not subjected to axial force, as a result, producing the moment of flexure of taking advantage of the distance between compressed member and the tensional element to obtain by with prestressing force on the particular cross section of structural element.Because the symbol of the moment of flexure that produces and structural element are owing to the opposite in sign that stands the moment of flexure of load, structural element is about the weight capacity increase of load.
In the former adoptable prestressing method of only using tensional element, compare with the size of pulling force, the moment of flexure that can apply is little, and this is because by utilizing the eccentric throw between cross section neutral axis and the tensional element to apply moment of flexure.In addition, the anchorage force of tensional element (anchorage) serves as the average pressure in the whole cross section of structural element.That is, required pressure can be applied to the part that stands to stretch owing to load, but control is owing to the stretching that load stands the compressed portion place is difficult.The most important thing is to use under material that has weakness aspect the stretching such as concrete situation, apply compression prestress to the part that stands tensile stress at structural element.Yet if according to the trend of elongated design, the cross section of structural element becomes less and uses more tensional element, the influence that the destruction of structural element is under pressure.
Simultaneously,, developed and used to apply the prestressed method that stretches, wherein compressed member has been installed in the top of PSC beam for tensile stress being applied to the part of supporting by the excessive compressive stress of load generation.Yet it is inconvenient exerting pressure to compressed member, and applies the part of compression jack reaction force and the part that compressed member is anchored on it is that reinforcement is required to it.In addition, because strain the process of tensional element and the process of compression compressed member respectively,, cause poor efficiency so construction phase increases.Equally, if load progressively increases, then applying prestressing according to the increase of load is unusual difficulty.At last, if the structure flaggy then can not carry out prestressing work again, this is because this process should be carried out on the top of structural element.Yet, can exert pressure simultaneously and pulling force by a tension process according to prestressing method of the present invention, because this process is carried out in the end at structural element, can carry out prestressing accordingly with applying stage by stage of load, and not need to be used for the intensifies process of grappling tensional element and compressed member.
In addition, because most popular concrete has very big compressive strength in the structural element that applies prestressing force and manufacturing opposing deflection, but tensile strength is very little, so should apply some compression prestress in addition with weak tensile strength in the compensation PSC beam.That is, it is desirable to very much, the PSC beam is subjected to the deflection that caused by load and applies the deflection opposite with described deflection by the prestressing method of using anchoring device according to an embodiment of the invention.Yet, withstand variable changing load reposefully in order to make structural element, need apply predetermined axial load and be in the compression to a certain extent so that aspect stretching, have the concrete of weakness.Thereby what be provided is a PSC beam, wherein except the tensional element that matches with compressed member another tensional element has been installed also.
Fig. 8 shows when when only using tensional element only pressure to be applied to structural element and when by the use compressed member pressure and pulling force all being applied to structural element, the prestressing force that produces in structural element.Figure above among Fig. 8 represents applying the stress that causes on the cross section of structural element positive bending moment when apply the prestressing of only using tensional element, and following figure represents the stress that causes on the cross section at structural element among Fig. 8 when the top by compressed member being arranged on structural element and the bottom that tensional element is arranged on structural element apply prestressing.
Among the figure above in Fig. 8, the pressure that equates with the pulling force of tensional element is applied to the cross section of structural element, and the position of making a concerted effort of power is the position of tensional element process.Power is eccentric, thereby exerts pressure and moment of flexure to structural element.As a result, apply high compression stress, under the situation of small eccentricity, apply low tensile stress, under the situation of large eccentricity distance, apply high tensile stress to top to top in the bottom.If the pressure of compressed member is identical with the pulling force of tensional element, then exerts pressure, and apply pulling force to the structural element cross section at compressed member place, top to the structural element cross section at tensional element place, bottom.Two power cancel each other out, and do not apply axial force to structural element thus.But, make prestressing force to be applied just in time on the contrary with the moment of flexure that produces by load because moment of flexure applies the difference between the position and only applies moment of flexure.
As described so far, the present invention has realized applying of optimum prestress by simple and easy process, so that structural element can be resisted deflection.
Simultaneously, in the present invention, can apply power to compressed member and tensional element simultaneously by a tension process, and can apply other prestressing force according to the process of load.In addition, because the distance between compressed member and the tensional element is eccentric, so can apply very big moment of flexure with very little power.Because less than the load that applies to structural element in axial direction, so can realize the ability of the very large load of response by freely increasing prestressing force.In addition, the design of structural element and manufacturing are easily, because do not need to be used for the design of the concentrated anchor portion of stress.
In addition, when the present invention during in the PSC of bridge beam, can be constructed the economic and beautiful bridge with low clearance and long span with the conventional prestressing method common application of only using tensional element.
In one embodiment of the invention, a tensional element 12 and two compressed members 13 match, but according to the shape and the width of structural element, also can be that a plurality of tensional elements 12 match with a plurality of compressed members 13.
To those skilled in the art clearly, under the situation that does not deviate from the spirit or scope of the present invention, can make various modification and variation in the present invention, thereby the present invention covers modification of the present invention and variation and their equivalent, and they all within the scope of the appended claims.
Claims (8)
1. one kind for the supporting capacity that increases the structural element that is used to resist moment of flexure and apply prestressed method, comprising:
In the tensile region of described structural element, one or more tensional elements are set and make this tensional element not link on the described structural element, and make described tensional element be exposed to the end of described structural element along the longitudinal direction of this structural element;
Along the longitudinal direction of this structural element one or more compressed members being set in the pressure zone of described structural element makes this compressed member not link on the described structural element;
The anchoring device that will be used to described compressed member is linked to each other with described tensional element is fixedly mounted in this compressed member, and strains described tensional element and make it pass described anchoring device,
Wherein the pulling force opposite reaction with described tensional element is applied to described compressed member as pressure by described anchoring device, makes simultaneously to apply pulling force and exert pressure to described compressed member to described tensional element.
2. the method for claim 1 wherein also comprises:
Link to each other and be exposed to outside grouting hose injection grouting agent by the space that sets in advance, make described grouting agent hardening, after the hardening step, unclamp described anchoring device then with between described tensional element, compressed member and the structural element.
3. one kind is used for applying prestressed anchoring device to the structural element that is provided with tensional element and compressed member, comprising:
Main body with first hole and second hole, the tensional element of bunchy are passed described first hole, and described second hole is formed on the both sides in first hole of described tensional element, and described compressed member passes described second hole respectively;
Set bolt, the compressed member that is used for passing described main body is separately fixed at the front and rear of described main body;
Have the form anchor in a plurality of the 3rd holes and close described first hole, each wire in the described tensional element can pass described the 3rd hole;
Be used for behind the described tensional element of tension, described tensional element being anchored to the wedge in described the 3rd hole,
Wherein reaction force is delivered to described form anchor and main body in the tension process of described tensional element, and described reaction force is delivered to described compressed member by described set bolt, thereby exerts pressure to this compressed member.
4. prestressed concrete beam comprises:
Concrete;
Compressed member, it is imbedded along the longitudinal direction in the described concrete top by means of sleeve pipe and makes described compressed member not link described concrete;
Imbed the tensional element with sweep in the described concrete bottom along the longitudinal direction, the median plane of this sweep upwards;
Be used for described tensional element and described compressed member are fixed on the anchoring device of described concrete end,
Wherein said tensional element passes described anchoring device and is exposed to the outside, and described compressed member is fixed to described anchoring device, and by drawing described tensional element, exerts pressure to described compressed member by described anchoring device.
5. prestressed concrete beam as claimed in claim 4, wherein said tensional element are imbedded by means of sleeve pipe but are not linked described structural element, and strain described tensional element by the post-tensioned method.
6. prestressed concrete beam as claimed in claim 4, wherein said tensional element has a plurality of, some tensional elements are mounted to and pass described anchoring device, and other tensional element is mounted to second anchoring device and links to each other, and this second anchoring device is different from described anchoring device.
7. as each described prestressed concrete beam in claim 4 and 6, wherein for the prestressed concrete beam continuous with another prestressed concrete beam is installed, one end of the described sleeve pipe on the described concrete of process top does not reach the end of described prestressed concrete beam but is installed to till the position, in this position, the end of described sleeve pipe separates a preset distance with the end of described prestressed concrete beam, and the compressed member that is arranged in the described sleeve pipe exposes the length the same with the length of being scheduled to and is embedded in the described concrete from an end of described sleeve pipe.
8. prestressed concrete beam as claimed in claim 7, comprising:
Make the described sleeve pipe that wherein is inserted with described tensional element be exposed to described concrete end;
Each sleeve pipe that will be exposed to the every end of this concrete under described concrete and another concrete situation adjacent one another are couples together;
Concrete is put into described concrete and another concrete connecting portion adjacent one another are; And
Inserting described tensional element in the connected sleeve pipe and straining described tensional element makes the connecting portion between different concrete exert pressure.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020040000210A KR100589797B1 (en) | 2004-01-05 | 2004-01-05 | Prestressing method with large eccentricity and no axial force by simple tensioning, the device for it, and the PSC beam utilizing the method and the device |
| KR1020040000210 | 2004-01-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1918342A CN1918342A (en) | 2007-02-21 |
| CN100529264C true CN100529264C (en) | 2009-08-19 |
Family
ID=34747760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005800050300A Expired - Fee Related CN100529264C (en) | 2004-01-05 | 2005-01-05 | Method of applying prestress and connecting means used therein and prestressed concrete beam therefrom |
Country Status (3)
| Country | Link |
|---|---|
| KR (1) | KR100589797B1 (en) |
| CN (1) | CN100529264C (en) |
| WO (1) | WO2005066419A1 (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100911545B1 (en) * | 2007-04-20 | 2009-08-10 | (주)삼현피에프 | Concrete structure having tube tube therein for accomodating compressive member to which compressive load applies |
| EP2063039A1 (en) * | 2007-11-26 | 2009-05-27 | Technical University of Denmark | Light-weight load-bearing structure |
| CN101736684B (en) * | 2008-11-24 | 2012-07-18 | 中铁十六局集团有限公司 | Non-standard simple supporting girder and manufacturing and mounting technology thereof |
| KR101043239B1 (en) * | 2008-12-23 | 2011-06-22 | (주)삼현피에프 | Prestressed segment concrete girder for bridge and manufacturing method thereof |
| KR101043240B1 (en) * | 2008-12-23 | 2011-06-22 | (주)삼현피에프 | Continuation structure of prestressed concrete girder bridge |
| KR100989811B1 (en) | 2010-02-23 | 2010-10-29 | 노윤근 | Prestressed concrete slab bridge which increased in the efficiency by large decenterizing concrete block and an arch rib |
| CN101845851A (en) * | 2010-04-09 | 2010-09-29 | 武汉理工大学 | Tendon-free prestressed concrete structure |
| EP2447446A1 (en) * | 2010-10-28 | 2012-05-02 | Sika Technology AG | Device for fastening tension members to reinforced concrete beams |
| JP2014521853A (en) * | 2011-08-12 | 2014-08-28 | ファウ・エス・エル・インターナツイオナール・アクチエンゲゼルシヤフト | Tensile member supply device |
| KR101167660B1 (en) | 2011-11-09 | 2012-07-20 | (주)삼현피에프 | Moment prestressed concrete girder and construction method thereof |
| CN102653968A (en) * | 2012-03-15 | 2012-09-05 | 中国建筑科学研究院 | Inner tensioning pre-stressed concrete single-layer I-shaped framework box-type structure |
| CN103195255B (en) * | 2013-03-29 | 2015-07-15 | 华北水利水电学院 | Construction method for prestressed carbon-fiber reinforced plastic (CFRP) reinforced concrete beam |
| KR101374701B1 (en) | 2013-06-25 | 2014-03-17 | 이엔이건설주식회사 | Concrete beam construction method with anchorage apparatus for bi-pressing compression member |
| CN103643154B (en) * | 2013-11-20 | 2016-01-06 | 江苏天舜金属材料集团有限公司 | A kind of with yield point elongation deformed bar and prestressed component constructional method thereof |
| CN104036149B (en) * | 2014-06-27 | 2017-02-01 | 中南大学 | Reactive powder concrete large-eccentric compression member limit load calculation method |
| KR102256091B1 (en) * | 2020-09-16 | 2021-05-26 | 주식회사 렉스코 | Psc girder fabricated using pre-tensioning stand apparatus for curved tendon and fabricated method thereof |
| CN112733293B (en) * | 2021-01-11 | 2023-12-22 | 西安科技大学 | Calculation method for head anchor bolts of underground coal mine rubber belt conveyor |
| KR102321582B1 (en) * | 2021-03-10 | 2021-11-05 | (주)한맥기술 | PSC I-type girder capable of adjusting transverse displacement using the tension member of the upper flange |
| KR102327977B1 (en) | 2021-05-10 | 2021-11-18 | 김찬녕 | Dual-prestressing girder using multi-pressing head and multi-pressing support apparatus and making, construction method thereof |
| CN114278099B (en) * | 2021-11-29 | 2023-04-07 | 中交世通(重庆)重工有限公司 | Prestress steel structure tool rod piece system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63126704A (en) * | 1986-11-17 | 1988-05-30 | オリエンタル建設株式会社 | Manufacture of pc girder through precast concrete block system |
| US5313749A (en) * | 1992-04-28 | 1994-05-24 | Conner Mitchel A | Reinforced steel beam and girder |
| KR100380637B1 (en) * | 1999-05-10 | 2003-04-16 | 주식회사 인터컨스텍 | Prestressed concrete girder of adjustable load bearing capacity for bridge and adjustment method for load bearing capacity of bridge |
-
2004
- 2004-01-05 KR KR1020040000210A patent/KR100589797B1/en active IP Right Grant
-
2005
- 2005-01-05 WO PCT/KR2005/000024 patent/WO2005066419A1/en active Application Filing
- 2005-01-05 CN CNB2005800050300A patent/CN100529264C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| KR100589797B1 (en) | 2006-06-14 |
| KR20040008236A (en) | 2004-01-28 |
| WO2005066419A1 (en) | 2005-07-21 |
| CN1918342A (en) | 2007-02-21 |
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