阅读说明：本技术 一种用于建筑高层建筑结构的预应力施工工艺 (Prestress construction process for high-rise building structure ) 是由 李航 杨小虎 李平 曾林 邬博亮 雷祥 刘小刚 冯杉 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种用于建筑高层建筑结构的预应力施工工艺,通过所述第一锚垫板及对应的所述第一锚具对预应力筋中所有所述钢丝绳进行分散锚固,避免了放张后对所述第一锚垫板周围结构应力集中的问题；所有所述第一锚垫板沿球面设置,即所有所述第一锚垫板的承力面被一个假想的球体顶住,受力更加均匀,利于锚固结构的稳定；通过将所述第二锚垫板、所述穴模和所述模板相对固定,使得所述第二锚垫板、所述穴模和所述模板用于穿过所述预应力筋的孔位不能发生错位,使得所述预应力筋能够一直垂直于所述模板外表面设置,满足工艺要求,确保高层建筑结构的预应力准确实施,该施工工艺步骤简单,操作方便,效果良好。(The invention discloses a prestress construction process for a high-rise building structure, which dispersedly anchors all steel wire ropes in prestressed tendons through a first anchor backing plate and a corresponding first anchor, so that the problem of stress concentration on the structure around the first anchor backing plate after tension releasing is avoided; all the first anchor backing plates are arranged along a spherical surface, namely the bearing surfaces of all the first anchor backing plates are propped by an imaginary sphere, so that the bearing is more uniform, and the stability of an anchoring structure is facilitated; through with second anchor backing plate cave mould with the template is fixed relatively, makes second anchor backing plate cave mould with the template is used for passing the hole site of prestressing tendons can not take place the dislocation, makes prestressing tendons can be perpendicular to always the template surface sets up, satisfies the technological requirement, ensures that high-rise building structure's prestressing force is accurate to be implemented, and this construction technology step is simple, convenient operation, and is respond well.)

1. The prestressed construction process for building high-rise building structure is characterized in that the prestressed tendon fixing end and the tensioning end are installed and comprise the following steps:

the prestressed tendon fixing end structure comprises a plurality of steel wire ropes, the steel wire ropes are sleeved in a corrugated pipe, the end parts of the steel wire ropes extend out of the corrugated pipe, each steel wire rope is correspondingly provided with a first anchor backing plate, each first anchor backing plate is correspondingly provided with a first anchor, each first anchor is used for anchoring the extending end of each steel wire rope to the corresponding first anchor backing plate, and all the first anchor backing plates are arranged along a spherical surface;

the unbonded prestressed tendon tensioning end structure comprises prestressed tendons, wherein the prestressed tendons sequentially penetrate through a second anchor backing plate, a cavity die and a template and extend to the outer side of the template, the cavity die is fixed relative to the second anchor backing plate and the template in the vertical plane direction of the prestressed tendons, spiral tendons are sleeved on the prestressed tendons, and the spiral tendons and the cavity die are respectively positioned on two sides of the second anchor backing plate;

there is bonding prestressing tendons stretch-draw end structure to include third anchor backing plate, second ground tackle, a plurality of reinforcing bar net piece and reserve the beard muscle, the third anchor backing plate passes through the horn tube and connects the bellows, all wire rope passes through the second ground tackle anchor in the third anchor backing plate, the third anchor backing plate is located the reinforcing bar net piece with in the steel reinforcement cage that the reservation beard muscle formed, after the prestressing tendons stretch-draw, pour the post-cast concrete among the stretch-draw end node.

2. The prestressed construction process for building high-rise building structure according to claim 1, wherein said prestressed tendon fixing end and tensioning end are installed before prestressed tendon processing, transportation, storage and prestressed tendon laying.

3. The prestressed construction process for building high-rise building structure according to claim 1, wherein said prestressed tendon fixing end and said tensioning end are installed and then tensioned.

4. The prestressed construction process for building high-rise building structure according to claim 3, wherein when said prestressed tendons are tensioned, the theoretical tensile elongation value Δ L of said curved prestressed tendons_TCalculated according to the following formula:

in the formula: f_j-the tensile force of the tendon;

A_p-the cross-sectional area of the tendon;

E_p-the modulus of elasticity of the tendon;

L_T-the length (m) of the channel from the tensile end to the fixed end;

k is the local deviation friction influence coefficient of each meter of pore canal;

u-coefficient of friction between tendon and tunnel wall;

theta is the total angle (rad) from the tensile end to the tangent of the curved channel section at the fixed end.

5. The prestressed construction process for building a high-rise building structure according to claim 1, wherein said end portion of said corrugated pipe is provided with a filler to form a sealed end.

6. The prestress construction process for building a high-rise building structure according to claim 1, wherein the first anchor backing plate comprises a backing plate body, a through hole and an installation groove body, the through hole is formed in the centroid of the backing plate body, the through hole is used for the steel wire rope to pass through the backing plate body, the installation groove body is connected to one side of the backing plate body, the groove bottom of the installation groove body is communicated with the through hole, the steel wire rope can pass through the through hole to enter the installation groove body, and the installation groove body is used for setting the first anchor.

7. The prestress construction process for building a high-rise building structure according to claim 6, wherein a chamfer is arranged between the base plate body and the installation groove body.

8. The pre-stress construction process for building a high-rise building structure according to claim 1, wherein a plurality of first limiting members are disposed on one side of the second anchor backing plate facing the formwork, a plurality of second limiting members are disposed on the inner side of the formwork, and the cavity formwork is provided with insertion holes corresponding to the first limiting members and insertion holes corresponding to the second limiting members.

9. The pre-stressing construction process for building a high-rise building structure according to claim 8, wherein said first position-limiting members are disposed at intervals along the periphery of said second anchor backing plate, and said second position-limiting members are disposed in one-to-one correspondence with said first position-limiting members.

10. The prestress construction process for building a high-rise building structure according to any one of claims 1 to 9, wherein a first fixing groove body is formed in one side, facing the formwork, of the second anchor backing plate, a plurality of second fixing groove bodies are formed in the inner side of the formwork, and two opposite ends of the hole formwork can be clamped in the first fixing groove body and the second fixing groove bodies respectively.

Technical Field

The invention relates to the field of building construction, in particular to a prestress construction process for a high-rise building structure.

Background

The modern high-rise building has high structure height, large span and large load, and adopts a prestress construction technology for improving bearing capacity and controlling deflection and cracks; the prestress needs to stretch the steel wire rope to generate prestress, no matter a pre-tensioning method or a post-tensioning method, one end of the steel wire rope needs to be anchored, different construction processes need to be applied to the bonded prestressed tendons and the unbonded prestressed tendons, and the fixed ends of the bonded prestressed tendons and the unbonded prestressed tendons are subjected to concentrated anchoring, so that concentrated stress can be caused, the service life of a high-rise building is influenced, and potential safety risks can be caused.

Disclosure of Invention

The invention aims to: aiming at the problems that the fixed ends of the existing prestressed tendons in the prior art are all subjected to concentrated anchoring to cause concentrated stress, influence the service life of a high-rise building and possibly cause potential safety risks no matter the prestressed tendons are bonded or unbonded, the prestressed construction process for the high-rise building structure is provided.

In order to achieve the purpose, the invention adopts the technical scheme that:

a prestressed construction process for building high-rise building structure, the prestressed tendon fixed end and the tensioning end are installed and comprise:

the prestressed tendon fixing end structure comprises a plurality of steel wire ropes, the steel wire ropes are sleeved in a corrugated pipe, the end parts of the steel wire ropes extend out of the corrugated pipe, each steel wire rope is correspondingly provided with a first anchor backing plate, each first anchor backing plate is correspondingly provided with a first anchor, each first anchor is used for anchoring the extending end of each steel wire rope to the corresponding first anchor backing plate, and all the first anchor backing plates are arranged along a spherical surface;

the unbonded prestressed tendon tensioning end structure comprises prestressed tendons, wherein the prestressed tendons sequentially penetrate through a second anchor backing plate, a cavity die and a template and extend to the outer side of the template, the cavity die is fixed relative to the second anchor backing plate and the template in the vertical plane direction of the prestressed tendons, spiral tendons are sleeved on the prestressed tendons, and the spiral tendons and the cavity die are respectively positioned on two sides of the second anchor backing plate;

there is bonding prestressing tendons stretch-draw end structure to include third anchor backing plate, second ground tackle, a plurality of reinforcing bar net piece and reserve the beard muscle, the third anchor backing plate passes through the horn tube and connects the bellows, all wire rope passes through the second ground tackle anchor in the third anchor backing plate, the third anchor backing plate is located the reinforcing bar net piece with in the steel reinforcement cage that the reservation beard muscle formed, after the prestressing tendons stretch-draw, pour the post-cast concrete among the stretch-draw end node.

By adopting the prestress construction process for the high-rise building structure, all the steel wire ropes in the prestressed tendons are dispersedly anchored through the first anchor backing plate and the corresponding first anchorage device, so that the problem of stress concentration on the structure around the first anchor backing plate after tension releasing is avoided; all the first anchor backing plates are arranged along a spherical surface, namely the bearing surfaces of all the first anchor backing plates are propped by an imaginary sphere, so that the bearing is more uniform, and the stability of an anchoring structure is facilitated; through with second anchor backing plate cave mould with the template is fixed relatively, makes second anchor backing plate cave mould with the template is used for passing the hole site of prestressing tendons can not take place the dislocation, makes prestressing tendons can be perpendicular to always the template surface sets up, satisfies the technological requirement, ensures that high-rise building structure's prestressing force is accurate to be implemented, and this construction technology step is simple, convenient operation, and is respond well.

Preferably, before the prestressed tendon fixed end and the tensioning end are installed, the prestressed tendon fixing device further comprises prestressed tendon processing, transportation and storage, and prestressed tendon laying.

Preferably, the prestressed tendon is tensioned after the fixed end and the tensioning end of the prestressed tendon are installed.

Further preferably, when the prestressed tendon is tensioned, the theoretical tensioning elongation value delta L of the curved prestressed tendon_TCalculated according to the following formula:

in the formula: f_j-the tensile force of the tendon;

A_p-the cross-sectional area of the tendon;

E_p-the modulus of elasticity of the tendon;

L_T-the length (m) of the channel from the tensile end to the fixed end;

k is the local deviation friction influence coefficient of each meter of pore canal;

u-coefficient of friction between tendon and tunnel wall;

theta is the total angle (rad) from the tensile end to the tangent of the curved channel section at the fixed end.

Preferably, the end of the bellows is provided with a filler to form a sealed end.

Preferably, first anchor backing plate includes backing plate body, through-hole and installation cell body, the through-hole is located backing plate body centroid department, the through-hole is used for wire rope passes the backing plate body, the installation cell body connect in backing plate body one side, just the tank bottom intercommunication of installation cell body the through-hole, wire rope can pass the through-hole gets into the installation cell body, the installation cell body is used for setting up first ground tackle.

Further preferably, a chamfer is arranged between the base plate body and the installation groove body.

Preferably, one side of the second anchor backing plate, which faces the template, is provided with a plurality of first limiting parts, the inner side of the template is provided with a plurality of second limiting parts, and the cavity mold is provided with a jack corresponding to the first limiting part and a jack corresponding to the second limiting part.

Further preferably, the first limiting parts are arranged at intervals along the periphery of the second anchor backing plate, and the second limiting parts and the first limiting parts are arranged in one-to-one correspondence.

Preferably, the second anchor backing plate is towards one side of template is equipped with first fixed cell body, the template inboard is equipped with the fixed cell body of a plurality of second, the relative both ends of cave mould can joint respectively in the first fixed cell body with in the fixed cell body of second.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

according to the prestress construction process for the high-rise building structure, all the steel wire ropes in the prestressed tendons are dispersedly anchored through the first anchor backing plate and the corresponding first anchorage device, so that the problem of stress concentration on the structure around the first anchor backing plate after tension releasing is avoided; all the first anchor backing plates are arranged along a spherical surface, namely the bearing surfaces of all the first anchor backing plates are propped by an imaginary sphere, so that the bearing is more uniform, and the stability of an anchoring structure is facilitated; through with second anchor backing plate cave mould with the template is fixed relatively, makes second anchor backing plate cave mould with the template is used for passing the hole site of prestressing tendons can not take place the dislocation, makes prestressing tendons can be perpendicular to always the template surface sets up, satisfies the technological requirement, ensures that high-rise building structure's prestressing force is accurate to be implemented, and this construction technology step is simple, convenient operation, and is respond well.

Drawings

FIG. 1 is a schematic view of a unbonded prestressed construction process;

FIG. 2 is a schematic view of the construction process of the skirt frame beam with bonded prestress;

FIG. 3 is a schematic view of a construction process of a shear wall with bonded prestressing;

FIG. 4 is a schematic diagram of the structure of the fixed end of the tendon;

FIG. 5 is a schematic view of the construction of the first anchor pad;

FIG. 6 is a schematic view of a unbonded tendon cavity die-stretched end configuration;

fig. 7 is a schematic view of another unbonded tendon cavity die-stretched end configuration;

fig. 8 is a schematic view of a tendon tensioning end construction with an adhesive tendon.

The labels in the figure are: 1-steel wire rope, 2-hole die, 3-second anchor backing plate, 31-first limiting piece, 32-first fixing groove body, 4-spiral rib, 5-template, 51-second limiting piece, 52-second fixing groove body, 6-corrugated pipe, 61-sealing end, 7-first anchor backing plate, 71-backing plate body, 72-through hole, 73-installation groove body, 74-chamfer, 8-first anchor, 9-third anchor backing plate, 10-second anchor, 11-reinforcing steel bar net piece, 12-reserved beard rib and 13-post-cast concrete.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Examples

As shown in fig. 1 to 8, the prestress construction process for building a high-rise building structure according to the present invention includes the steps of:

A. processing, transporting and storing the prestressed tendons:

the prestressed steel wire ropes 1 are firstly transported to a professional production workshop for processing, blanking is carried out according to the size and the number of blanking lists, each tensioning end of each prestressed steel wire rope 1 is designed with a reserved tensioning length and a curve increasing length, and the blanking of the prestressed steel wire ropes 1 is cut by a grinding wheel cutting machine, so that electric welding and gas welding are forbidden.

The unbonded prestressed ribs and accessories are lifted to the greatest extent to avoid collision and extrusion, coiled transportation is adopted during transportation, light loading and light unloading are required, throwing is strictly forbidden, sharp objects damage the surfaces of the unbonded prestressed ribs and the accessories, rubber tubes need to be sleeved on steel ropes for lifting appliances, or flexible lifting belts are adopted, the unbonded prestressed ribs are strictly forbidden to be bound by the steel ropes, the skins of the unbonded prestressed ribs are prevented from being damaged during loading and unloading, if the unbonded prestressed ribs and the accessories are damaged, the unbonded prestressed ribs and the accessories are timely repaired by plastic adhesive tapes, and the winding and overlapping length of the unbonded prestressed ribs and the accessories is 1/3 width.

After the prestressed tendons are transported to a construction site, the prestressed tendons are classified into bundles according to different floors and specifications, are formed into a tray, are hung, and are stacked in a dry and flat place in order; when the stacks are stacked in the open air, the stacks need to be covered with rain cloth, and the lower sides of the stacks need to be additionally provided with skids to prevent corrosion; the anchorage and the fittings should be stored indoors, and measures are taken to prevent rust strictly. When the prestressed tendons are stacked in the open air, the prestressed tendons need to be covered with rain cloth, and a skid needs to be additionally arranged below the prestressed tendons to prevent the anchorage device and the steel wires from being corroded; strictly forbidding collision and treading on the stacked finished products, and avoiding damaging the plastic sleeve and the anchorage device; contact electric welding operation is avoided, and damage is avoided.

B. Laying prestressed tendons:

b1, as shown in fig. 1, unbonded tendons are laid: the unbonded prestressed tendons are respectively 172 single unbonded prestressed tendons in nine layers and ten layers, the eleven layers are 494 non-bonded prestressed tendons in total, and the unbonded prestressed tendons are natural curves; preparation work before rib laying: preparing an end mould, namely punching holes with the aperture of 25mm on the end mould by adopting a wood mould and a steel mould according to the flat and section positions of the prestressed tendons, and supporting a beam bottom mould and paving a common steel reinforcement framework; laying prestressed tendons: arranging the prestressed tendons on the upper part of the common lower iron bar in a straight line and binding the prestressed tendons on the lower iron bar; the prestressed tendons need to be laid in a strict laying sequence along the concrete pouring direction according to a flowing water construction section, the design rise of the prestressed tendons is guaranteed, construction disorder is avoided, the prestressed tendons need to be laid by paying special attention to the coordination of the moving direction and the position of the prestressed tendons, particularly, the prestressed tendons and the prestressed tendons cannot be inverted in the crossing and the supporting seat, and the prestressed tendons are forbidden to be disconnected.

B2, as shown in fig. 2 or 3, with bonded tendons laid: preparation work before laying: laying non-prestressed tendons, namely laying a framework of the non-prestressed tendons, wherein a quick-release system is adopted for the floor slab template and the supports in order to save the using amount of the template; preparing an end die: according to the practical situation and the design requirement of the project, the embedded horn tube is fixed on the end die before die assembly, so the end die is prepared in advance, and the size of the end die is accurate; preparing a frame stud: setting a frame rib at an interval of about 1.0m according to a design drawing, wherein the frame rib adopts a twisted steel bar with the diameter of 12 mm; blanking of the corrugated pipe 6: during blanking, the length of a joint between pipes is not less than 30cm, two ends of the joint are respectively and completely screwed into the joint, the joint is sealed by using an adhesive tape, the pipe diameter of the joint is required to be one size larger than the diameter of the pipeline, an exhaust hole is reserved in the corrugated pipe 6, the hole can also be used as a grouting hole during multi-span, and the pipe joint and the air outlet pipe are sealed by using a sealing adhesive tape to prevent slurry leakage; blanking the prestressed tendons and assembling the fixed end extrusion anchor.

Laying a corrugated pipe 6: installing the frame vertical bars, and firmly welding or binding the frame vertical bars and the stirrups, wherein the top surfaces of the frame vertical bars are determined by subtracting the radius of the corrugated pipe 6 from the rise from the bottom of the plate according to the center line of the prestressed bar shown in a drawing; in order to ensure accurate rise of the prestressed reinforcement and smooth curve, when the prestressed beam is constructed, the positioning bars are welded or bound firmly according to the requirement of the rise of the prestressed reinforcement in a construction drawing and the position of the marked positioning bar; installing a horn tube: installing the horn tube on an end die or a non-prestressed reinforcement framework according to the position shown by a design drawing; penetration of the corrugated pipe 6: the corrugated pipe 6 is penetrated according to the drawing position, 4-5 persons are used for arranging along the two sides of the girder, the corrugated pipe 6 is penetrated from one end, after the pipe is completely penetrated, the two ends are inserted into the positioned horn pipes, and the joint of the corrugated pipe 6 and the horn pipes is wound and sealed by using adhesive tapes, so that slurry leakage is avoided; principle of laying the corrugated tube 6: when laying, the steel wire should be positioned strictly according to the design drawing and the requirements of the construction scheme, and the size and the linear shape are ensured; the positioning of the horn tube needs to be accurate; the horizontal position of the corrugated pipe 6 must be along the central line or be symmetrical to the central line, and S bending is not required to be performed; sealing all the connecting parts such as the positions of the horn pipe and the corrugated pipe 6, the positions of reserved mounting group anchors at the stretching end and the end of the exhaust hole. Sealing various joints by using adhesive tapes without slurry leakage; after laying and in the concrete pouring process, the corrugated pipe 6 is strictly prohibited from being flattened and damaged, and the corrugated pipe 6 is strictly prohibited from being welded by gas.

Penetrating prestressed tendons: the steel strand needs to be blanked in fixed length by adopting a method of splitting and penetrating for multiple times. The steel strand wire is cut by a grinding wheel saw, and cannot be cut by electrogas welding. The prestressed tendon is penetrated from the fixed end to the stretching end to avoid distortion. If the on-site fixed end has no steel bar penetrating position, the corrugated pipe 6 and the prestressed steel bars are assembled well and are synchronously performed with the non-prestressed steel bars. After the steel strand penetrates into the pore channel, electrogas welding is not needed to be used so as to avoid the reduction of the strength of the prestressed tendon.

C. The fixed end and the tensioning end of the prestressed tendon are installed:

c1, as shown in fig. 4, the prestressed tendon fixing end structure in this embodiment includes a plurality of steel wire ropes 1, the steel wire ropes 1 are sleeved in a corrugated pipe 6, an end of each steel wire rope 1 extends out of the corrugated pipe 6, each steel wire rope 1 is correspondingly provided with a first anchor plate 7, each first anchor plate 7 is correspondingly provided with a first anchor 8, each first anchor 8 is used for anchoring an extending end of the steel wire rope 1 to the corresponding first anchor plate 7, an end of the corrugated pipe 6 is provided with a filler to form a sealing end 61, so that cement paste is prevented from being poured into the corrugated pipe 6 when concrete is poured, and the steel wire rope 1 extends out of the corrugated pipe 6 by at least 30 cm.

As shown in fig. 5, the first anchor pad 7 includes a pad body 71, a through hole 72 and an installation groove 73, the through hole 72 is disposed at a centroid of the pad body 71, the through hole 72 is used for the steel wire rope 1 to pass through the pad body 71, the installation groove 73 is connected to one side of the pad body 71, a groove bottom of the installation groove 73 is communicated with the through hole 72, the steel wire rope 1 can pass through the through hole 72 and enter the installation groove 73, and the installation groove 73 is used for arranging the first anchor 8; specifically, backing plate body 71 with installation cell body 73 is integrated into one piece component, backing plate body 71 with be equipped with chamfer 74 between the installation cell body 73, the additional strengthening structure performance reduces backing plate body 71 warp, first ground tackle 8 is the clip formula anchor, all first anchor backing plate 7 is along the sphere setting, all promptly the bearing surface of first anchor backing plate 7 is withstood by an imaginary spheroid, and the atress is more even, does benefit to the stability of anchor structure. By adopting the arrangement of the prestressed tendon fixed end structure, all the steel wire ropes 1 in the prestressed tendon are dispersedly anchored through the first anchor backing plate 7 and the corresponding first anchorage device 8, so that the problem of stress concentration on the surrounding structure of the first anchor backing plate 7 after tension releasing is avoided; all the first anchor backing plates 7 are arranged along a spherical surface, namely the bearing surfaces of all the first anchor backing plates 7 are propped by an imaginary sphere, so that the bearing is more uniform, and the stability of an anchoring structure is facilitated; the prestressed tendon fixed end node is simple in structure, convenient to use and good in effect.

C2, as shown in fig. 6, unbonded tendon stretching end structure includes prestressing tendons 1 in this embodiment, prestressing tendons 1 runs through second anchor backing plate 3, cave mould 2 and template 5 in proper order, and extends to the 5 outsides of template, cave mould 2 is in prestressing tendons 1 vertical plane direction for second anchor backing plate 3 with template 5 is fixed, the cover is equipped with spiral muscle 4 on prestressing tendons 1, spiral muscle 4 with cave mould 2 is located respectively second anchor backing plate 3 both sides. Specifically, one side of the second anchor backing plate 3 facing the template 5 is provided with a plurality of first limiting members 31, the inner side of the template 5 is provided with a plurality of second limiting members 51, the cavity mold 2 is provided with jacks corresponding to the first limiting members 31 and jacks corresponding to the second limiting members 51, the first limiting members 31 are arranged at intervals along the periphery of the second anchor backing plate 3, the second limiting members 51 are arranged in one-to-one correspondence with the first limiting members 31, the first limiting members 31 are bolts or limiting members, and the second limiting members 51 are bolts or limiting members; the cavity die 2 is a polyphenyl structural member, is light in weight and is convenient to install and set. By adopting the structure, through the insertion and connection matching of the first limiting part 31, the second limiting part 51 and the corresponding jacks, the cavity die 2 can be fixed relative to the second anchor backing plate 3 and the template 5 in the vertical plane direction of the prestressed tendon 1, so that the prestressed tendon 1 can be always perpendicular to the outer surface of the template 5, the second anchor backing plate 3, the cavity die 2 and the template 5 can not be dislocated when passing through the hole of the prestressed tendon 1, and the prestressed tendon 1 can be always perpendicular to the outer surface of the template 5, thereby meeting the process requirements.

As shown in fig. 7, the difference from the unbonded tendon tensioning end structure is that in the structure, a first fixing groove 32 is formed in one side, facing the template 5, of the second anchor pad 3, a plurality of second fixing grooves 52 are formed in the inner side of the template 5, and two opposite ends of the cavity mold 2 can be respectively clamped in the first fixing groove 32 and the second fixing grooves 52. By adopting the structure, the first fixing groove body 32 and the second fixing groove body 52 are respectively clamped with the hole die 2, so that the hole die 2 is fixed relative to the second anchor backing plate 3 and the template 5 in the vertical direction of the prestressed tendon 1, and the prestressed tendon 1 can be always perpendicular to the outer surface of the template 5.

In the embodiment, the unbonded prestressed tendons are required to be perpendicular to the outer surface of the template 5, and a straight line segment of which the length is not less than 30cm is required behind the template 5; a spiral rib is arranged behind each tension end bearing plate and is required to be tightly attached to the bearing plate; the length of the pre-stressed tendon reserved at the tensioning end meets the design requirement.

C3, as shown in fig. 8, there is bonding prestressed reinforcement stretch-draw end structure in this embodiment to include third anchor backing plate 9, second anchor 10, a plurality of reinforcing bar net pieces 11 and reserved beard muscle 12, third anchor backing plate 9 passes through the horn tube and connects bellows 62, all wire rope 1 passes through second anchor 10 anchor in third anchor backing plate 9, third anchor backing plate 9 is located reinforcing bar net piece 11 with in the reinforcing bar cage that reserved beard muscle 12 formed, after the prestressed reinforcement stretch-draw, pour behind concrete 13 in the stretch-draw end node pouring, prefer in this embodiment second anchor 10 is the anchor of group anchor, behind pour concrete 13 is C40 micro-expansion fine aggregate concrete.

Wherein, the length (reserved stretching length) of the prestressed tendon extending out of the bell mouth meets the stretching requirement; the interface between the bell mouth and the corrugated pipe 6 and the interface between the exhaust hole and the corrugated pipe 6 are firmly sealed by using an adhesive tape, so that slurry leakage is avoided; the end parts of the corrugated pipes 6 at the stretching end and the fixed end are firmly plugged by using fillers, so that cement paste is prevented from being poured into the corrugated pipes 6 when concrete is poured; the prestressed tendons are perpendicular to the outer surface of the bell mouth, and a straight line section which is not less than 30cm is required behind the pressure bearing plate; binding reinforcing mesh sheets behind the stretching ends of the prestressed ribs according to requirements, installing a spiral rib (the shear wall has bonding prestress) or binding reinforcing mesh sheets (the skirt house has bonding prestress) on each fixed end, and requiring the spiral rib or the reinforcing mesh sheets to be tightly attached to the bearing plate.

C4, installation of the tensioning end anchorage system: the exposed length of the prestressed tendon is determined according to the length required by a tensioning machine, the prestressed tendon is perpendicular to the pressure-bearing plate at the tensioning end, and a straight line section not less than 300mm is required behind the pressure-bearing plate; the minimum bending radius required by a single prestressed tendon is not less than 2.0m for a phi 15.2mm steel wire rope 1; the tension end is provided with a spiral rib which is tightly close to the bearing plate or the connected anchor plate and ensures the centering and the fixing reliability with the prestressed rib as much as possible; the exposed length of the prestressed tendon should meet the requirements of design and tension construction.

D. Tensioning the prestressed tendons:

d1, tensioning equipment:

the unbonded prestressed machine tool adopts YCN-23 type single-hole tensioning jacks and matched oil pumps, the shear wall prestressed force adopts 100t group anchor tensioning jacks, and the skirt house is provided with bonded prestressed tendons and adopts 250t group anchor tensioning jacks.

The pump top is periodically calibrated (once every 6 months) according to the actual tension force required by the design and prestressing process. During actual use, the oil pressure meter reading value corresponding to the control tension force value is calculated by the calibration value on the calibration certificate and is used as the basis for operation of a tensioning person. The calibration book is given in the tension data.

D2 erection of tension platform

Before tensioning, a tensioning operation platform is erected by a general contract unit at a tensioning end at a position inconvenient for tensioning construction, and the tensioning operation platform meets the following requirements:

firstly, to the stretch-draw of unbonded prestressing tendons in the board, if the position such as the elevartor shaft of stretch-draw end, should set up operation platform, platform stand people position should be in prestressing force stretch-draw end height about 900mm position down, and platform width (platform edge apart from wall distance) is not less than 700mm, and platform length (the length along the wall) is not less than 1500mm, faces the sky limit and has the guardrail that accords with the safety regulation, and the bearing is according to being no less than 3 adult's considerations.

Secondly, the shear wall is subjected to bonding prestress tensioning, the height of a platform standing person part from the bottom of the floor bearing plate is 1800mm, the width of the platform (the distance between the edge of the platform and the wall surface) is not less than 700mm, the length of the platform (the length along the wall surface) is not less than 1500mm, a guardrail meeting safety regulations is arranged on a vacant edge, and the bearing is considered according to at least 3 adults. When the corresponding floor support plate is constructed during tensioning, tensioning operation holes are reserved on the floor support plate in advance, two tensioning operation holes are reserved at each position, the tensioning operation holes are located right above the tensioning end, the distance between each tensioning operation hole and the corresponding floor support plate is 250mm and 550mm, and the aperture is 200 mm.

D3, tension quality control standard and requirement:

during tensioning, the actual tensioning force is controlled by using equipment calibrated on time and reading on an oil pressure gauge of the equipment, and the actual elongation value is compared with a theoretically calculated elongation value for checking (namely, the tensioning quality adopts a stress-strain double control method).

Theoretical elongation value calculation formula, theoretical tension elongation value delta L of curve prestressed tendon_TCalculated according to the following formula:

in the formula: f_j-the tensile force of the tendon;

A_p-the cross-sectional area of the tendon;

E_p-the modulus of elasticity of the tendon;

L_T-the length (m) of the channel from the tensile end to the fixed end;

k is the local deviation friction influence coefficient of each meter of pore canal;

u-coefficient of friction between tendon and tunnel wall;

theta is the total angle (rad) from the tensile end to the tangent of the curved channel section at the fixed end.

Checking the cleaning condition of the tensioning end carefully, and tensioning the tensioning end without carrying sundries.

Checking the anchors one by one before use.

Tensioning is carried out strictly according to the operation rules, and the oil feeding speed is controlled.

The mounting position of the jack is on the same axis with the prestressed tendon.

Sixthly, breakage of the steel wire during tensioning is reported to an engineer, and the engineer determines treatment according to specific conditions.

And when the difference between the measured elongation value and the calculated elongation value exceeds + 6% or-6%, stopping tensioning, reporting to an engineer for analysis, and then continuing tensioning.

D4, tensioning time and tensioning flow:

skirt house frame beam has bonding prestressing force

And (3) after the strength of the prestressed beam concrete reaches 100% of the design value and meets other tensioning conditions, tensioning the prestressed tendons, wherein the tensioning sequence is as follows: and sequentially tensioning along the structure.

② the shear wall has adhesive prestress

The tensioning is carried out in three batches, as detailed in the following table:

tensioning sequence: and sequentially tensioning according to the structure.

Third, there is no prestress of binding in the floor bearing plate

Batch tensioning, detailed in the following table:

location of a body part	Thickness of floor slab	Time of stretching
			9-storey floor	150mm	Post-completion tensioning of the body
10-storey floor	150mm	Post-completion tensioning of the body
			11-storey floor	200mm	Tensioning after 30-storey floor completion

Tensioning sequence: and sequentially tensioning according to the structure.

D5, tension control stress and actual tension force:

and (3) controlling a stress value according to the stretching of the prestressed tendons (the control stress sigma con is 1395Mpa), and carrying out 3% over-stretching on the actual stretching force according to the actual condition, so that the actual stretching force P of each bundle of the steel wire rope 1 is 201.0 kN.

And tensioning the prestressed tendons after the concrete reaches the strength required by the design, wherein the specific tensioning time is carried out according to the civil engineering construction progress requirement. And (5) reporting the pressure test strength of the same-condition maintenance test block of the concrete at the tensioning part during tensioning.

D6, quality control method and requirements:

during stretching, the actual stretching force is controlled by using equipment calibrated on time and controlling the reading on an oil pressure gauge, and the actual elongation value is compared with the theoretically calculated elongation value for checking. (namely, the tension quality adopts a stress-strain double-control method).

Checking the cleaning condition of the tensioning end carefully, and tensioning the tensioning end without carrying sundries.

Checking the anchors one by one before use.

Tensioning is carried out strictly according to the operation rules, and the oil feeding speed is controlled.

The mounting position of the jack is on the same axis with the prestressed tendon.

Sixthly, the steel wire rope 1 is broken during tensioning, an engineer is reported, and the engineer decides treatment according to specific conditions.

And when the difference between the measured elongation value and the calculated elongation value exceeds + 6% or-6%, stopping tensioning, reporting to an engineer for analyzing reasons, and then continuing tensioning.

D7, stretch recording:

and (3) simultaneously making tensioning records of the single prestressed tendons during tensioning, wherein the tensioning record data is real and effective, and the tensioning can be carried out after supervision and acceptance.

E. And (3) tensioning end treatment of the tensioned prestressed tendon:

the anchoring area of the prestressed tendon must have strict sealing protection measures, and the prestressed tendon is prevented from being rusted due to the entry of water vapor, so that the prestressed tendon should be immediately subjected to end sealing protection after the tensioning is finished.

Cutting off redundant prestressed tendons by using a grinding wheel, wherein the length of the cut prestressed tendons exposed out of the anchor device clamping piece is not less than 30mm, and electric arc blowing is strictly forbidden.

Cleaning up sundries around the tensioning end and wetting the surrounding concrete with water.

And (3) plugging the post-cast part at the tensioning end by using micro-expansion fine stone concrete not lower than the structural mark to protect the anchorage device, wherein the plugging is carried out by paying attention to compaction.

And repairing the concrete surface until the appearance requirement is met.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.