CN101979802A - Extra-large area concrete construction method - Google Patents

Extra-large area concrete construction method Download PDF

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CN101979802A
CN101979802A CN 201010532899 CN201010532899A CN101979802A CN 101979802 A CN101979802 A CN 101979802A CN 201010532899 CN201010532899 CN 201010532899 CN 201010532899 A CN201010532899 A CN 201010532899A CN 101979802 A CN101979802 A CN 101979802A
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stretch
draw
tendon
reinforcement
stress
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唐际宇
方思忠
赵磊
戈祥林
张勋胜
范波
黄启权
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China Construction Eighth Engineering Division Co Ltd
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Abstract

The invention discloses an extra-large area concrete construction method, which comprises: computing a temperature stress by a finite-element analysis process; arranging stress bars according to the result of the computation of the temperature stress and design requirements; and tensioning the stress bars. By arranging the prestress bars and generating the prepressing stress in reinforced concrete, air shrinkage generated in the hardening of concrete and tensile stress generated in hydration heat contraction are counteracted basically, so the cracking of concrete are relieved and prevented.

Description

The overlarge area concrete construction method
Technical field
The present invention relates to a kind of job practices, particularly the overlarge area concrete construction method.
Background technology
According to the shrinkage joint distance computation formula that proposes in " engineering structures Crack Control " book as can be known, the shrinkage joint need be set fully, just must reduce the concrete temperature difference and concrete contraction, or improve concrete limit stretch value; But improving concrete limit position, to stretch value be very difficult, thereby can only be by managing to reduce the concrete heat of hydration and contraction, the control concrete is not more than concrete ultimate elongation because of the stretching strain that the temperature difference or contraction cause, then concrete can not established the shrinkage joint and do not ftractureed.
In the prior art, there is overlength super large concrete structure seamless design problem, and overlength super large concrete beam and plate, and structure bottom large tracts of land adopts rubber vibration isolation cushion, cause level and vertical rigidity dyscalculia, thereby influence the problem of prestressing without bondn design.
Summary of the invention
The objective of the invention is to overcome the defective of prior art, a kind of new overlarge area concrete construction method is provided.
The technological means of employing of the present invention is: a kind of overlarge area concrete construction method comprises: calculation of temperature stresses, adopt the finite element method calculation of temperature stresses; Stress rib is set, stress rib is set according to the result of temperature stress calculation and design needs; This stress rib of stretch-draw.
Wherein, in the calculation of temperature stresses, the shock insulation layer segment adopts the effect of spring with the simulation rubber pad, and the temperature difference is got 20oC.
Wherein, be provided with in the stress rib, comprise Vierendeel girder arrangement of reinforcement, girder arrangement of reinforcement, secondary beam arrangement of reinforcement, floor arrangement of reinforcement.
In the Vierendeel girder arrangement of reinforcement step, the Vierendeel girder apolegamy does not have bonding curve muscle, and the crack is no more than 0.2mm under prestressing force, horizontal thermal stresses and vertical uniform load q.
Girder serves as the control cross section with spaning middle section and bearing cross section.
The arrangement of reinforcement of every secondary beam adopts the identical method of girder to calculate.
In the floor arrangement of reinforcement, length direction and short direction are shunk and Creep Loss is got with value.
Wherein, in the stretch-draw step, be the pretensioning floor, the post tensioning floor beam is by the symmetrical stretch-draw of the outwards basic maintenance in centre.Unbonded tendon single tension in the plate, the unbonded tendon symmetry stretch-draw in the beam.
Wherein, the unbonded tendon stretch value in the plate is calculated as follows:
Figure 755424DEST_PATH_IMAGE001
Wherein, Fpm is that the average stretching force (KN) of unbonded prestressing tendon is got the pulling force of stretch-draw end and fixed end (during the stretch-draw of two ends, get span centre) average of deduction friction loss back pull, LP is the length (mm) of unbonded prestressing tendon, AP is the section area (mm2) of unbonded prestressing tendon, and EP is the modulus of elasticity (KN/mm2) of unbonded prestressing tendon.
In addition, the unbonded tendon stretch value in the beam is calculated as follows:
Figure 512640DEST_PATH_IMAGE002
Wherein, Δ Lt is an elongation value of stretching, LT is the physical length of parabolic type presstressed reinforcing steel, Fj is a tension of prestressed tendon end stretching force, Ap is the presstressed reinforcing steel sectional area, and Ep is the presstressed reinforcing steel modulus of elasticity, and K is duct, an every meter hole partial deviations frictional influence coefficient, μ is the friction factor between presstressed reinforcing steel and the cell walls, and θ is the total angle (rad) from the stretch-draw end to fixed end curve duct part tangent line.Wherein:
Figure 779673DEST_PATH_IMAGE003
Positive progressive effect of the present invention is:
1) by presstressed reinforcing steel is being set, in steel concrete, set up compressive pre-stress, can roughly offset the tensile stress that the drying shrinkage that produces in the course of hardening and heat of hydration shrinkage occur, thereby cracking appears in the deduction and exemption concrete;
2) at utmost reduce the prestressed stretch-draw loss;
3) by using finite element software Midas that floor is calculated in the thermal stresses of operational phase, the shock insulation layer segment supports the effect of simulation rubber pad with spring in model, overcome structure bottom large tracts of land employing rubber vibration isolation cushion in the prior art, cause level and vertical rigidity dyscalculia, thereby influence the problem of prestressing without bondn design.
Description of drawings
Fig. 1 is the flow chart of method of the present invention;
Fig. 2 is the schematic diagram of finite element analysis;
Fig. 3 is that shock insulation layer spring supports schematic diagram;
Fig. 4 is a cooling back bulk deformation schematic diagram;
Fig. 5 is a girder arrangement of reinforcement schematic diagram;
Fig. 6 is each sectional position schematic diagram of floor;
Fig. 7 is the tension of prestressed tendon schematic diagram.
The specific embodiment
Below in conjunction with the accompanying drawing illustrated embodiment the present invention is elaborated.
Fig. 1 is the flow chart of method of the present invention.As shown in Figure 1, a kind of overlarge area concrete construction method 100 comprises: calculation of temperature stresses 110, adopt the finite element method calculation of temperature stresses; Stress rib 120 is set, stress rib is set according to the result of temperature stress calculation and design needs; This stress rib 130 of stretch-draw.
Use finite element software Midas that floor is calculated in the thermal stresses of operational phase, the shock insulation layer segment supports the effect of simulating rubber pad with spring in model, the data input that its level and vertical rigidity provide according to designing unit.Computation model as shown in Figure 2.Shock insulation layer spring supports as shown in Figure 3.Calculate the temperature difference and be taken as 20 ℃, by integral body cooling calculation of temperature stresses, the structural entity distortion after the cooling as shown in Figure 4.
The Vierendeel girder apolegamy does not have bonding curve muscle, and the crack is no more than 0.2mm under prestressing force, horizontal thermal stresses and vertical load (for a long time) effect.
Thermal stresses adopts the Finite Element Method result calculated, the result of calculation that vertical load adopts designing unit to provide, according to the explanation of " adopting the expansive concrete technology; in steel concrete, set up certain prestressing force (precompression of 0.2~0.7MPa) " in the design leader, considered the compressive pre-stress of 0.4MPa in addition.
Each layer girder divides 9m to stride, 12m strides and 18m strides three classes.Total span is no more than 40m and adopts tensioned at one end, surpasses 40m and adopts two ends stretch-draw.Every beam arrangement of reinforcement all (JGJ92-2004) has carried out the checking computations of crack width according to " unbonded prestressed concrete structure tecnical regulations ".
Girder is with the C(span centre) cross section and E(bearing) cross section serve as control the cross section, see Fig. 5.
Each level beam divides that 9m strides, 12m strides two classes, and total span is no more than 40m and adopts tensioned at one end, surpasses 40m and adopts two ends stretch-draw.The arrangement of reinforcement of every secondary beam adopts the identical method of girder to calculate.
Cloth prestressing force straight line muscle in the floor, total span is no more than 48m.Adopt tensioned at one end, surpass 48m and adopt two ends stretch-draw.
The presstressed reinforcing steel loss is calculated in the floor: because of concrete shrinkage and the proportion that in loss, accounts for of creeping less, so length direction and short direction are shunk and Creep Loss is got value together; Control stress for prestressing: 0.7fptk.When calculating in the plate loss of prestress, the position in A, B, C, D, E cross section as shown in Figure 6
For avoiding the prestressed stretch-draw loss, take rational tension sequence extremely important.Overall tension sequence is the pretensioning floor, and the post tensioning floor beam is by the outwards basic order that keeps symmetrical stretch-draw in centre.Unbonded tendon single tension in the plate, the unbonded tendon symmetry stretch-draw in the beam.Model is made in examination stretch-draw earlier before stretch-draw, leads the way with model, and large tracts of land is opened again then.
Preceding center integral tension is seen Fig. 7 in proper order.During every layer of tension of prestressed tendon, 4 stretch-draw teams and groups by the centre to around stretch-draw, stretch-draw pretensioning directions X, stretch-draw Y direction again is specific to the disposable stretch-draw both direction of each little subregion.
Control stress for prestressing is determined: the stretching force size of presstressed reinforcing steel directly influences the prestressing force effect.Stretching force is high more, and the prestress value of foundation is big more, and the crack resistance of member is also good more; But presstressed reinforcing steel in use often was under the high-stress state, and it is approaching that the load and the rupture load in crack appears in member, often not significantly warning before destruction, and this is dangerous.In addition, excessive as stretching force, cause the excessive or prestretching district of member antiarch the crack to occur, also be disadvantageous.Otherwise the pulling anchor cable stage loss of prestress is big more, and the prestress value of foundation is low more, and then the crack may appear in member too early, also is unsafe.
Therefore, the constructor should accurately set up prestress value, and informs that when abnormal conditions occurring the designer solves.
The stretching construction order of every bundle and every presstressed reinforcing steel:
Cleaning bearing plate, steel strand → wear anchor ring, lay intermediate plate → lay jack → erecting tools anchor → be stretched to initial stress → long L1 of the cylinder of measurement jack under initial stress → the be stretched to long L2 of the proof stress → cylinder of measurement jack under proof stress → check elongation value of stretching → anchoring jack backhaul → unload jack.
Board prestress muscle stretch value is that the unbonded prestressing tendon stretch value is calculated as follows:
Figure 916256DEST_PATH_IMAGE001
Wherein, Fpm is that the average stretching force (KN) of unbonded prestressing tendon is got the pulling force of stretch-draw end and fixed end (during the stretch-draw of two ends, get span centre) average of deduction friction loss back pull, LP is the length (mm) of unbonded prestressing tendon, AP is the section area (mm2) of unbonded prestressing tendon, and EP is the modulus of elasticity (KN/mm2) of unbonded prestressing tendon.
The actual stretch value of unbonded prestressing tendon should begin to measure the classification record when initial stress is control stress for prestressing 10% left and right sides.
Its stretch value can be pressed formula by measurement and determine:
Figure 522818DEST_PATH_IMAGE004
In the formula:
Figure 516182DEST_PATH_IMAGE005
Be the actual measurement stretch value of initial stress between the maximum stretching force; Be the reckoning stretch value below the initial stress, can calculate according to the relation that stretching force in the elastic range is directly proportional with stretch value and determine;
Figure 945206DEST_PATH_IMAGE007
Be the elastic compression value of concrete component in stretching process.
The plate inner member less to average compressive pre-stress,
Figure 406275DEST_PATH_IMAGE007
Can omit and disregard.
Girder pre-stressed muscle stretch value is calculated as follows:
Figure 773802DEST_PATH_IMAGE002
Wherein, Δ Lt is an elongation value of stretching, LT is the physical length of parabolic type presstressed reinforcing steel, Fj is a tension of prestressed tendon end stretching force, Ap is the presstressed reinforcing steel sectional area, and Ep is the presstressed reinforcing steel modulus of elasticity, and K is duct, an every meter hole partial deviations frictional influence coefficient, μ is the friction factor between presstressed reinforcing steel and the cell walls, and θ is the total angle (rad) from the stretch-draw end to fixed end curve duct part tangent line.Wherein:
Figure 15428DEST_PATH_IMAGE003
Its duct and corner friction factor according to the form below are determined.
The unbonded prestressing tendon friction factor
Figure 2010105328993100002DEST_PATH_IMAGE008
Presstressed reinforcing steel should avoid taking place disconnected, stripped thread as far as possible in stretching process.Should suspend the ascertain the reason back that takes corrective action of stretch-draw and recover stretch-draw if disconnected, stripped thread occurs, disconnected, stripped thread total amount should exceed 1% of this cross section sum.Each bundle steel strand fracture of wire must not exceed 1, otherwise must heavily draw.
The length value that the measurement of stretch value is stretched out with measurement stretch-draw jack cylinder is measured.When being stretched to initial stress, measure the length value L 1 that jack cylinder is stretched out, measure the length value L 2 that jack cylinder is stretched out when being stretched to proof stress, difference L2-L1 according to the jack extension elongation, extrapolate stretch value L0 before the initial stress with diagram method, the stretch value of actual presstressed reinforcing steel is L2-L1+ L0; When the curtailment of jack, jack needs repeatedly backward journey, and when measuring stretch value, each backward journey should measure the extension elongation of its cylinder, adds up then, determines the actual stretch value of presstressed reinforcing steel at last.
In the stretching process be that main the measurement by oil meter reading and stretch value carried out two keyholed back plates reasons to tension of prestressed tendon with the Stress Control, its actual stretch value is ± 6% with the relative allowable variation of design calculation theory.As go beyond the scope and should stop stretch-draw immediately, can continue stretch-draw after waiting to ascertain the reason.Should be conscientiously during tension of prestressed tendon the actual measurement stretch value of every bundle steel strand be performed record, carry out the arrangement of system then, perform the examination data of handing over.
Use finite element software Midas that floor is calculated in the thermal stresses of operational phase, the shock insulation layer segment supports the effect of simulating rubber pad with spring in model, the data input that its level and vertical rigidity provide according to designing unit.
Overall tension sequence is the pretensioning floor, and the post tensioning floor beam is by the outwards basic order that keeps symmetrical stretch-draw in centre.Unbonded tendon single tension in the plate, the unbonded tendon symmetry stretch-draw in the beam.At utmost reduce the prestressed stretch-draw loss by above method.
By the control of stretching force and the two indexs of stretch value, effectively controlled the crack of Overlong Concrete Structure in the stretching process.
Although the present invention describes according to its preferred implementation, there are the change, displacement and the various substitute equivalents that fall in the scope of the invention.Here the example that provides only is illustrative, rather than limitation of the present invention.
For the sake of simplicity, this manual has omitted the description to known technology.

Claims (13)

1. an overlarge area concrete construction method is characterized in that, this method comprises:
Calculation of temperature stresses adopts the finite element method calculation of temperature stresses;
Stress rib is set, stress rib is set according to the result of temperature stress calculation and design needs;
This stress rib of stretch-draw.
2. method according to claim 1 is characterized in that, in the calculation of temperature stresses, the shock insulation layer segment adopts the effect of spring with the simulation rubber pad.
3. method according to claim 2 is characterized in that in the calculation of temperature stresses, the temperature difference is got 20oC.
4. method according to claim 1 is characterized in that, is provided with in the stress rib, comprises Vierendeel girder arrangement of reinforcement, girder arrangement of reinforcement, secondary beam arrangement of reinforcement, floor arrangement of reinforcement.
5. method according to claim 4 is characterized in that, in the Vierendeel girder arrangement of reinforcement step, the Vierendeel girder apolegamy does not have bonding curve muscle, and the crack is no more than 0.2mm under prestressing force, horizontal thermal stresses and vertical uniform load q.
6. method according to claim 4 is characterized in that, in the girder arrangement of reinforcement step, girder serves as the control cross section with spaning middle section and bearing cross section.
7. method according to claim 4 is characterized in that, every secondary beam arrangement of reinforcement adopts the identical method of girder to calculate.
8. method according to claim 4 is characterized in that, in the floor arrangement of reinforcement, length direction and short direction are shunk and Creep Loss is got with value.
9. method according to claim 1 is characterized in that, in the stretch-draw step, is the pretensioning floor, and the post tensioning floor beam is by the symmetrical stretch-draw of the outwards basic maintenance in centre.
10. method according to claim 9 is characterized in that, the unbonded tendon single tension in the plate, the unbonded tendon symmetry stretch-draw in the beam.
11. method according to claim 10 is characterized in that, the unbonded tendon stretch value in the plate is calculated as follows:
Wherein, Fpm is that the average stretching force of unbonded prestressing tendon is got the pulling force of stretch-draw end and the average of fixed end or span centre deduction friction loss back pull, LP is the length of unbonded prestressing tendon, and AP is the section area of unbonded prestressing tendon, and EP is the modulus of elasticity of unbonded prestressing tendon.
12. method according to claim 10 is characterized in that, the unbonded tendon stretch value in the beam is calculated as follows:
Figure 2010105328993100001DEST_PATH_IMAGE002
Wherein, Δ Lt is an elongation value of stretching, LT is the physical length of parabolic type presstressed reinforcing steel, Fj is a tension of prestressed tendon end stretching force, Ap is the presstressed reinforcing steel sectional area, and Ep is the presstressed reinforcing steel modulus of elasticity, and K is duct, an every meter hole partial deviations frictional influence coefficient, μ is the friction factor between presstressed reinforcing steel and the cell walls, and θ is the total angle from the stretch-draw end to fixed end curve duct part tangent line.
13. method according to claim 12 is characterized in that, wherein:
Figure 2010105328993100001DEST_PATH_IMAGE003
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102436722A (en) * 2011-12-05 2012-05-02 中国水利水电科学研究院 Temperature control and crack prevention monitoring method of concrete dam
WO2013166971A1 (en) * 2012-05-08 2013-11-14 悉地国际设计顾问(深圳)有限公司 Method for analyzing temperature difference shrinkage effects on concrete structures
CN103669868A (en) * 2013-12-30 2014-03-26 中国建筑第八工程局有限公司 Recursive flow process construction method for ultra-long concrete floor structure
CN104947916A (en) * 2015-06-17 2015-09-30 重庆建工住宅建设有限公司 Extra-large area concrete floor structure shrinkage control construction technology
CN107675887A (en) * 2017-08-28 2018-02-09 中交武汉港湾工程设计研究院有限公司 A kind of external interim prestressed concrete control cracking method
CN108560830A (en) * 2018-05-24 2018-09-21 北京市建筑设计研究院有限公司 A kind of Seismic Isolation of Isolation Layer prestressing force tensile device
CN114808656A (en) * 2022-05-27 2022-07-29 长江勘测规划设计研究有限责任公司 Method for reducing creep deflection of concrete beam
CN118171379A (en) * 2024-05-15 2024-06-11 中冶建筑研究总院有限公司 Reverse determination and forward compensation method for elastic compression prestress loss of complex structure

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1504961A (en) * 1974-02-06 1978-03-22 Conspan Invest Prestressed concrete members
DE2754834A1 (en) * 1977-12-09 1979-06-13 Johann Jacob Dr Ing Rieve Prestressed concrete tension and pressure zone reinforcement - is which zero line value of fracture condition in within defined limits
US4205029A (en) * 1974-02-06 1980-05-27 Forrest Esli J Pre-stressed concrete construction
EP0366664A1 (en) * 1987-05-05 1990-05-09 Kautar Oy Prestressed construction element of composite structure and method for element fabrication.
CN201180366Y (en) * 2008-03-14 2009-01-14 中建三局建设工程股份有限公司 Ultra-large area concrete construction surface construction and partition seam remaining construction apparatus
CN101503915A (en) * 2009-03-09 2009-08-12 中国建筑第六工程局有限公司 Construction method for ultra-large area, ultra-thin non-agglutination pre-stress integral pond baseboard
CN101684670A (en) * 2008-09-23 2010-03-31 曹学仁 Mass concrete temperature stress releasing device and novel technology for guiding crack setting

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1504961A (en) * 1974-02-06 1978-03-22 Conspan Invest Prestressed concrete members
US4205029A (en) * 1974-02-06 1980-05-27 Forrest Esli J Pre-stressed concrete construction
DE2754834A1 (en) * 1977-12-09 1979-06-13 Johann Jacob Dr Ing Rieve Prestressed concrete tension and pressure zone reinforcement - is which zero line value of fracture condition in within defined limits
EP0366664A1 (en) * 1987-05-05 1990-05-09 Kautar Oy Prestressed construction element of composite structure and method for element fabrication.
CN201180366Y (en) * 2008-03-14 2009-01-14 中建三局建设工程股份有限公司 Ultra-large area concrete construction surface construction and partition seam remaining construction apparatus
CN101684670A (en) * 2008-09-23 2010-03-31 曹学仁 Mass concrete temperature stress releasing device and novel technology for guiding crack setting
CN101503915A (en) * 2009-03-09 2009-08-12 中国建筑第六工程局有限公司 Construction method for ultra-large area, ultra-thin non-agglutination pre-stress integral pond baseboard

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
《建筑施工手册第四版缩印本》 20030930 《建筑施工手册》第四版编写组 建筑施工手册 658-660 11-13 , 1 *
《施工技术》 20101031 许小金,唐际宇,唐锋,王晓锋 昆明新机场航站楼超长混凝土结构施工技术 1-4 1-3 第39卷, 第10期 2 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102436722A (en) * 2011-12-05 2012-05-02 中国水利水电科学研究院 Temperature control and crack prevention monitoring method of concrete dam
CN102436722B (en) * 2011-12-05 2014-03-12 中国水利水电科学研究院 Temperature control and crack prevention monitoring method of concrete dam
WO2013166971A1 (en) * 2012-05-08 2013-11-14 悉地国际设计顾问(深圳)有限公司 Method for analyzing temperature difference shrinkage effects on concrete structures
CN103669868A (en) * 2013-12-30 2014-03-26 中国建筑第八工程局有限公司 Recursive flow process construction method for ultra-long concrete floor structure
CN103669868B (en) * 2013-12-30 2015-09-09 中国建筑第八工程局有限公司 The recursion cross construction method of ultra-long concrete floor structure
CN104947916A (en) * 2015-06-17 2015-09-30 重庆建工住宅建设有限公司 Extra-large area concrete floor structure shrinkage control construction technology
CN107675887A (en) * 2017-08-28 2018-02-09 中交武汉港湾工程设计研究院有限公司 A kind of external interim prestressed concrete control cracking method
CN107675887B (en) * 2017-08-28 2019-07-05 中交武汉港湾工程设计研究院有限公司 A kind of external interim prestressed concrete control cracking method
CN108560830A (en) * 2018-05-24 2018-09-21 北京市建筑设计研究院有限公司 A kind of Seismic Isolation of Isolation Layer prestressing force tensile device
CN108560830B (en) * 2018-05-24 2024-03-22 北京市建筑设计研究院有限公司 Prestressed tensile device for shock insulation layer
CN114808656A (en) * 2022-05-27 2022-07-29 长江勘测规划设计研究有限责任公司 Method for reducing creep deflection of concrete beam
CN114808656B (en) * 2022-05-27 2023-10-24 长江勘测规划设计研究有限责任公司 Method for reducing creep deflection of concrete beam
CN118171379A (en) * 2024-05-15 2024-06-11 中冶建筑研究总院有限公司 Reverse determination and forward compensation method for elastic compression prestress loss of complex structure

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Application publication date: 20110223