CN105842153A - Testing apparatus and method for coefficient of friction resistance of prestressed pipe - Google Patents

Abstract

The invention discloses a testing apparatus and method for the coefficient of friction resistance of a prestressed pipe. The testing apparatus comprises a tensioning jack, a driving-end sensor, a tool anchor, a driven-end sensor, a bell mouth and an anchor backing plate, wherein the bell mouth passes through a prestressing tendon and is arranged at the end part of the prestressed pipe in a beam; the driving-end sensor and the driven-end sensor are arranged at the end parts of the prestressed pipe, pass through the prestressing tendon and are fixed at the tail end of the prestressing tendon by the tensioning jack and the tool anchor; the anchor backing plate is arranged between the bell mouth and the driving-end and driven-end sensors; and the central axes of the installation positions of the bell mouth and the anchor backing plate are superposed with the central axis of the prestressed pipe. According to the invention, the testing apparatus is reasonable in structure; the testing method is convenient to operate; scientific evaluation is provided for design and construction of a post-tensioning-process prestressed concrete beam; potential safety hazards in engineering construction can be eliminated; and construction quality of the prestressed pipe is guaranteed.

Description

A kind of prestress pipe coefficient of friction resistance test device and method

Technical field

The present invention relates to prestress pipe coefficient of friction resistance field tests, particularly relate to a kind of prestress pipe coefficient of friction resistance test device And method.

Background technology

In prestressed concrete construction, the reason causing loss of prestress is a lot, and the time of generation also successively differs.Prestressing force The stress loss that pipe friction causes is one of five principal elements.Prestress pipe friction loss and pipeline material character, power muscle The bundle factor such as kind and tensioning process is relevant.

Prestress pipe friction loss is used coefficient of friction resistance μ and pipeline deviation factor k to characterize by engineering, although design specification Give the span of some of the recommendations, but based on the needs to Practical Project quality assurance and Construction control, and in different works In journey, it is the fact that pipe friction factor difference is bigger, before post-stressed stretch-draw, needs construction bar same to same building site Pipe friction factor under part carries out practical measurement, thus provides for the control of stretching force, elongation and camber etc. during stretch-draw Foundation.

The main purpose of prestress pipe friction test is as follows:

(1) can be taken calculating parameter with test design the most correct, prevent calculated prestressing force loss less than normal, the safety reducing engineering is hidden Suffer from；

(2) reliable basis is provided for construction, in order to accurately determine control stress for prestressing and power muscle elongation；

(3) construction quality of pipeline and tensioning process can be checked.

Summary of the invention

It is an object of the invention to for above-mentioned technical problem, it is provided that a kind of rational in infrastructure, easy to operate prestress pipe frictional resistance system Number detection device and method, the design and construction for post-tensioned prestressing concrete beam provides scientific evaluation, eliminates engineering construction Potential safety hazard, it is ensured that the construction quality of prestress pipe.

Technical scheme:

For solving above-mentioned technical problem, the present invention provides a kind of prestress pipe coefficient of friction resistance detection device, and it includes stretch-draw jack, Drive end sensor, moveable anchor, Partner sensor, horn mouth and anchor plate.

Horn mouth passes prestressing tendon, is arranged on the end of prestress pipe in beam body；Drive end sensor, Partner sensor are arranged In the end of prestress pipe, it passes prestressing tendon, stretch-draw jack and moveable anchor are fixed on the end of prestressing tendon；Loudspeaker It is provided with anchor plate between mouth and drive end sensor, Partner sensor；Horn mouth, the axis of anchor plate installation site Overlap with the axis of prestress pipe, make the prestressing tendon in prestress pipe disengage with horn mouth, anchor plate.

Further, described drive end sensor, Partner sensor are punching pressure transducer, the axis of its installation site Overlap with the axis of prestress pipe, make the prestressing tendon in prestress pipe take off with drive end sensor, Partner sensor From contact.

Further, this device also includes tester, and it is connected with drive end sensor, Partner sensor by data wire.

The method of testing that a kind of above-mentioned prestress pipe coefficient of friction resistance test device is corresponding, comprises the following steps:

S1, according to project scale, selects four prestress pipes of typical case's beam slab, and collects the layout of prestressing tendon and in advance should The relevant parameter of hydraulic piping；

S2, builds prestress pipe coefficient of friction resistance test device, by stretch-draw jack, drive end sensor, moveable anchor, quilt Moved end sensor, horn mouth and anchor plate are arranged on the prestressing tendon in prestress pipe；Drive end sensor, Partner pass Sensor, horn mouth, the axis of anchor plate installation site overlap with the axis of prestress pipe；

S3, is connected drive end sensor, Partner sensor with tester by data wire, debugging tester；

S4, using drive end sensor place end as drive end, the other end is as Partner, and point Pyatyi is step by step at prestressing tendon Load tension force；During grading tension, read drive end sensor, reading that Partner sensor is corresponding respectively, and measure prestressing force The elongation of bundle；

S5, exchanges the drive end in step S4, Partner, and point Pyatyi loads tension force at prestressing tendon step by step；Grading tension Time, read drive end sensor, reading that Partner sensor is corresponding respectively, and measure the elongation of prestressing tendon；

S6, repeats S4-S5, tests other three prestress pipes respectively, and record test data；

S7, according to the drive end of four pipeline stretch-draw bundles measured, Partner observed pressure value P1, P2, passes through linear regression Determine its ratio；

S8, utilizes method of least square, by pipe friction loss computing formula: σ_l1=σ_con[1-e^-(μθ+kx)], derive k and μ Computing formula:

$\left\{\begin{array}{c}\mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{{\mathrm{\θ}}_i}^2+k\underset{i=1}{\overset{n}{\Σ}}{l}_i{\mathrm{\θ}}_i-\underset{i=1}{\overset{n}{\Σ}}{y}_i{\mathrm{\θ}}_i=0\\ \mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\θ}}_i{l}_i+k\underset{i=1}{\overset{n}{\Σ}}{l_i}^2-\underset{i=1}{\overset{n}{\Σ}}{y}_i{l}_i=0\end{array}\right.$

Calculated prestressing force pipeline partial deviations affect coefficient k, coefficientoffrictionμ；

Wherein,

σ_conFor stretching end steel strand wires control stress under anchor (MPa)；

μ is the coefficient of friction of deformed bar and duct wall；

θ is to the angle sum (rad) calculating cross section curve pipe section tangent line from stretching end；

K is that every meter of pipeline partial deviations affect coefficient to rub；

X is to the duct length in calculating cross section from stretching end, can approximate the projected length taking this segment pipe on the component longitudinal axis (m)；

y_iIt is the i-th-ln that prestress pipe is corresponding (P₂/P₁) value；

l_iIt it is presstressed reinforcing steel space curve length (m) that i-th prestress pipe is corresponding；

θ_iIt it is presstressed reinforcing steel space curve cornerite (rad) that i-th prestress pipe is corresponding；

N is the prestress pipe number of actual measurement, and different linear presstressed reinforcing steel number is not less than 2；

The pipeline partial deviations of Actual measurement in step S8 are affected the value that coefficient k, coefficientoffrictionμ and specification are recommended by S9 Relatively, if its impact is within engineering allowed band, then choosing pipeline partial deviations by specification affects coefficient k, coefficient of friction μ。

Further, in step S4, S5, the load on prestressing tendon according to 20%, 40%, 60%, 80%, 100% point Pyatyi loads.

The method have the benefit that

A kind of prestress pipe coefficient of friction resistance test device and method that the present invention provides, this apparatus structure is reasonable, method of testing Easy to operate, the design and construction for post-tensioned prestressing concrete beam provides scientific evaluation, and the safety eliminating engineering construction is hidden Suffer from, it is ensured that the construction quality of prestress pipe.

Accompanying drawing explanation

Fig. 1 is connection diagram of the present invention；

Fig. 2 is high side N13 prestress pipe observed pressure value P1 in the specific embodiment of the invention, P2 linear fit curve chart；

Fig. 3 is downside N13 prestress pipe observed pressure value P1, P2 linear fit curve chart in the specific embodiment of the invention；

Fig. 4 is high side N15 prestress pipe observed pressure value P1 in the specific embodiment of the invention, P2 linear fit curve chart；

Fig. 5 is downside N15 prestress pipe observed pressure value P1, P2 linear fit curve chart in the specific embodiment of the invention.

Wherein:

1. stretch-draw jack；2. drive end sensor；3. moveable anchor；4. Partner sensor；5. beam body；6. horn mouth；7. anchor Backing plate；8. data wire；9. tester；10. prestressing tendon；11. prestress pipes.

Detailed description of the invention

Below in conjunction with specific embodiments and the drawings, a kind of prestress pipe coefficient of friction resistance of the present invention is tested device and method to carry out in detail Describe in detail bright:

A kind of prestress pipe coefficient of friction resistance test device shown in Fig. 1, it includes stretch-draw jack 1, drive end sensor 2, Moveable anchor 3, Partner sensor 4, horn mouth 6 and anchor plate 7.

Horn mouth 6 through prestressing tendon 10, is arranged on the end of prestress pipe 11 in beam body 5；Drive end sensor 2, Partner sensor 4 is arranged on the end of prestress pipe 11, and it passes prestressing tendon 10, by stretch-draw jack 1 and instrument Anchor 3 is fixed on the end of prestressing tendon 10.

It is provided with anchor plate 7 between horn mouth 6 and drive end sensor 2, Partner sensor 4；Horn mouth 6, anchor plate The axis of 7 installation sites overlaps with the axis of prestress pipe 11, make prestressing tendon in prestress pipe 11 10 with Horn mouth 6, anchor plate 7 disengage.

Described drive end sensor 2, Partner sensor 4 are punching pressure transducer, the axis of its installation site with The axis of prestress pipe 11 overlaps, and makes prestressing tendon 10 in prestress pipe 11 and drive end sensor 2, passive End sensor 4 disengages.

This device also includes tester 8, and it is connected with drive end sensor 2, Partner sensor 4 by data wire 8.

The method of testing that a kind of above-mentioned prestress pipe coefficient of friction resistance test device is corresponding, comprises the following steps:

S1, according to project scale, selects four prestress pipes 11 of typical case's beam slab, and collect prestressing tendon 10 layout and The relevant parameter of prestress pipe 11；

S2, builds prestress pipe coefficient of friction resistance test device, by stretch-draw jack 1, drive end sensor 2, moveable anchor 3, Partner sensor 4, horn mouth 6 and anchor plate 7 are arranged on the prestressing tendon 10 in prestress pipe 11；Actively In end sensor 2, Partner sensor 4, horn mouth 6, the axis of anchor plate 7 installation site and prestress pipe 11 Dead in line；

S3, is connected drive end sensor 2, Partner sensor 4 with tester 9 by data wire 8, debugging tester 9；

S4, using drive end sensor 2 place end as drive end, the other end is as Partner, and point Pyatyi is step by step at prestressing force Bundle 10 loading tension force；During grading tension, read drive end sensor 2, the reading of Partner sensor 4 correspondence respectively, and Measure the elongation of prestressing tendon 10；

S5, exchanges the drive end in step S4, Partner, and point Pyatyi loads tension force at prestressing tendon 10 step by step；Classification During stretch-draw, read drive end sensor 2, the reading of Partner sensor 4 correspondence respectively, and measure stretching of prestressing tendon 10 Long amount；

S6, repeats S4-S5, tests other three prestress pipes 11 respectively, and record test data；

S7, according to the drive end of four pipeline stretch-draw bundles 10 measured, Partner observed pressure value P1, P2, by linearly Recurrence determines its ratio；

S8, utilizes method of least square, by pipe friction loss computing formula: σ_l1=σ_con[1-e^-(μθ+kx)], derive k and μ Computing formula:

$\left\{\begin{array}{c}\mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{{\mathrm{\θ}}_i}^2+k\underset{i=1}{\overset{n}{\Σ}}{l}_i{\mathrm{\θ}}_i-\underset{i=1}{\overset{n}{\Σ}}{y}_i{\mathrm{\θ}}_i=0\\ \mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\θ}}_i{l}_i+k\underset{i=1}{\overset{n}{\Σ}}{l_i}^2-\underset{i=1}{\overset{n}{\Σ}}{y}_i{l}_i=0\end{array}\right.$

Calculated prestressing force pipeline partial deviations affect coefficient k, coefficientoffrictionμ；Wherein,

σ_conFor stretching end steel strand wires control stress under anchor (MPa)；

μ is the coefficient of friction of deformed bar and duct wall；

θ is to the angle sum (rad) calculating cross section curve pipe section tangent line from stretching end；

K is that every meter of pipeline partial deviations affect coefficient to rub；

X is to the duct length in calculating cross section from stretching end, can approximate the projected length taking this segment pipe on the component longitudinal axis (m)；

y_iIt is the i-th-ln that prestress pipe is corresponding (P₂/P₁) value；

l_iIt it is presstressed reinforcing steel space curve length (m) that i-th prestress pipe is corresponding；

θ_iIt it is presstressed reinforcing steel space curve cornerite (rad) that i-th prestress pipe is corresponding；

N is the prestress pipe number of actual measurement, and different linear presstressed reinforcing steel number is not less than 2；

The pipeline partial deviations of Actual measurement in step S8 are affected the value that coefficient k, coefficientoffrictionμ and specification are recommended by S9 Relatively, if its impact is within engineering allowed band, then choosing pipeline partial deviations by specification affects coefficient k, coefficient of friction μ。

In step S4, S5, the load on prestressing tendon 10 is according to 20%, and 40%, 60%, 80%, 100% point of Pyatyi adds Carry.

Below according to specific embodiment in detail, prestress pipe coefficient of friction resistance method of testing is described in detail.

S1, according to project scale, selects four prestress pipes 11 of typical case's beam slab, and collect prestressing tendon 10 layout and The relevant parameter of prestress pipe 11.

Specifically, select high side N13, high side N15, downside N13, tetra-prestress pipes 11 of downside N15, and collect The layout of prestressing tendon 10 and relevant parameter, as shown in table 1.

Table 1 prestressing tendon is arranged and pipeline relevant parameter table

S2, builds prestress pipe coefficient of friction resistance test device, by stretch-draw jack 1, drive end sensor 2, moveable anchor 3, Partner sensor 4, horn mouth 6 and anchor plate 7 are arranged on the prestressing tendon 10 in prestress pipe 11；Actively In end sensor 2, Partner sensor 4, horn mouth 6, the axis of anchor plate 7 installation site and prestress pipe 11 Dead in line；

S3, is connected drive end sensor 2, Partner sensor 4 with tester 9 by data wire 8, debugging tester 9；

S4, using drive end sensor 2 place end as drive end, the other end is as Partner, and point Pyatyi is step by step at prestressing force Bundle 10 loading tension force；During grading tension, read drive end sensor 2, the reading of Partner sensor 4 correspondence respectively, and Measure the elongation of prestressing tendon 10；

S5, exchanges the drive end in step S4, Partner, and point Pyatyi loads tension force at prestressing tendon 10 step by step；Classification During stretch-draw, read drive end sensor 2, the reading of Partner sensor 4 correspondence respectively, and measure stretching of prestressing tendon 10 Long amount；

S6, repeats S4-S5, tests other three prestress pipes 11 respectively, and record test data；Concrete survey Examination data are as shown in table 2-table 5.

Table 2 high side N13 bundle test result

Table 3 downside N13 restraints test result

Table 4 high side N15 bundle test result

Table 5 downside N15 restraints test result

S7, according to the drive end of four pipeline stretch-draw bundles 10 measured, Partner observed pressure value P1, P2, by linearly Recurrence determines its ratio；Fig. 2-Fig. 5 is drive end, the ratio of Partner observed pressure value determined by linear regression.

S8, utilizes method of least square, by pipe friction loss computing formula: σ_l1=σ_con[1-e^-(μθ+kx)], derive k and μ Computing formula:

$\left\{\begin{array}{c}\mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{{\mathrm{\θ}}_i}^2+k\underset{i=1}{\overset{n}{\Σ}}{l}_i{\mathrm{\θ}}_i-\underset{i=1}{\overset{n}{\Σ}}{y}_i{\mathrm{\θ}}_i=0\\ \mathrm{\μ}\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\θ}}_i{l}_i+k\underset{i=1}{\overset{n}{\Σ}}{l_i}^2-\underset{i=1}{\overset{n}{\Σ}}{y}_i{l}_i=0\end{array}\right.$

Calculated prestressing force pipeline partial deviations affect coefficient k, coefficientoffrictionμ.Its result of calculation, as shown in table 6.

Table 6 prestress pipe coefficient of friction resistance result of calculation

The pipeline partial deviations of Actual measurement in step S8 are affected the value that coefficient k, coefficientoffrictionμ and specification are recommended by S9 Relatively, if its impact is within engineering allowed band, then choosing pipeline partial deviations by specification affects coefficient k, coefficient of friction μ。

From table 6, in the present embodiment, the pipeline partial deviations of actual measurement affect coefficient k, coefficientoffrictionμ is respectively 0.00138,0.268, this is very close to design load 0.0015,0.25, and the impact of its difference is within engineering allowed band 's.

A kind of prestress pipe coefficient of friction resistance test device and method that the present invention provides, this apparatus structure is reasonable, method of testing Easy to operate, the design and construction for post-tensioned prestressing concrete beam provides scientific evaluation, and the safety eliminating engineering construction is hidden Suffer from, it is ensured that the construction quality of prestress pipe.

The present invention is not limited to above-mentioned embodiment, and anyone can draw other various forms of products under the enlightenment of the present invention, but No matter making any change in its shape or structure, every have same as the present application or akin technical scheme, all falls within this Within the protection domain of invention.

Claims (5)

1. a prestress pipe coefficient of friction resistance test device, including stretch-draw jack (1), drive end sensor (2), Moveable anchor (3), Partner sensor (4), horn mouth (6) and anchor plate (7)；Horn mouth (6) Through prestressing tendon (10), it is arranged on the end of beam body (5) interior prestress pipe (11)；Drive end passes Sensor (2), Partner sensor (4) are arranged on the end of prestress pipe (11), and it passes prestressing force Bundle (10), is fixed on the end of prestressing tendon (10) by stretch-draw jack (1) and moveable anchor (3)；Loudspeaker It is provided with anchor plate (7) between mouth (6) and drive end sensor (2), Partner sensor (4)； It is characterized in that, horn mouth (6), axis and the prestress pipe (11) of anchor plate (7) installation site Axis overlap.

The prestress pipe coefficient of friction resistance the most according to claim 1 test device, it is characterised in that described Drive end sensor (2), Partner sensor (4) are punching pressure transducer, in its installation site Axis overlaps with the axis of prestress pipe (11).

The prestress pipe coefficient of friction resistance the most according to claim 1 test device, it is characterised in that this device Also including tester (8), it is by data wire (8) and drive end sensor (2), Partner sensor (4) connect.

4. in a claims 1 to 3 described in any one the prestress pipe coefficient of friction resistance test device corresponding Method of testing, it is characterised in that comprise the following steps:

S1, according to project scale, selects four prestress pipes (11) of typical case's beam slab, and collects prestressing tendon (10) Layout and the relevant parameter of prestress pipe (11)；

S2, build the prestress pipe coefficient of friction resistance test device, by stretch-draw jack (1), drive end sensor (2), Moveable anchor (3), Partner sensor (4), horn mouth (6) and anchor plate (7) are arranged on prestressed pipe On prestressing tendon (10) in road (11)；Drive end sensor (2), Partner sensor (4), loudspeaker Mouth (6), the axis of anchor plate (7) installation site overlap with the axis of prestress pipe (11)；

S3, by data wire (8) by drive end sensor (2), Partner sensor (4) and tester (9) Connect, debugging tester (9)；

S4, using drive end sensor (2) place end as drive end, the other end is as Partner, and point Pyatyi is step by step Tension force is loaded at prestressing tendon (10)；During grading tension, read drive end sensor (2), passive respectively The reading that end sensor (4) is corresponding, and measure the elongation of prestressing tendon (10)；

S5, exchanges the drive end in step S4, Partner, and point Pyatyi loads at prestressing tendon (10) step by step opens Power；During grading tension, read drive end sensor (2), the reading of Partner sensor (4) correspondence respectively, And measure the elongation of prestressing tendon (10)；

S6, repeats S4-S5, tests other three prestress pipes (11) respectively, and record test data；

S7, according to the drive end of four pipelines stretch-draw bundle (10) measured, Partner observed pressure value P1, P2, Its ratio is determined by linear regression；

S8, utilizes method of least square, by pipe friction loss computing formula: σ_l1=σ_con[1-e^-(μθ+kx)], derive K and μ computing formula:

$\left\{\begin{array}{c}\mathrm{\μ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{{\mathrm{\θ}}_i}^2+k\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{l}_i{\mathrm{\θ}}_i-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{y}_i{\mathrm{\θ}}_i=0\\ \mathrm{\μ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{\θ}}_i{l}_i+k\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{l_i}^2-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{y}_i{l}_i=0\end{array}\right.$

Calculated prestressing force pipeline partial deviations affect coefficient k, coefficientoffrictionμ；Wherein,

σ_conFor stretching end steel strand wires control stress under anchor (MPa)；

μ is the coefficient of friction of deformed bar and duct wall；

θ is to the angle sum (rad) calculating cross section curve pipe section tangent line from stretching end；

K is that every meter of pipeline partial deviations affect coefficient to rub；

X is to calculating the duct length in cross section from stretching end, can approximate that to take the projection on the component longitudinal axis of this segment pipe long Degree (m)；

y_iIt is the i-th-ln that prestress pipe is corresponding (P₂/P₁) value；

l_iIt it is presstressed reinforcing steel space curve length (m) that i-th prestress pipe is corresponding；

θ_iIt it is presstressed reinforcing steel space curve cornerite (rad) that i-th prestress pipe is corresponding；

N is the prestress pipe number of actual measurement, and different linear presstressed reinforcing steel number is not less than 2；

The pipeline partial deviations of Actual measurement in step S8 are affected coefficient k, coefficientoffrictionμ and specification recommendation by S9 Value compare, if its impact within engineering allowed band, then by specification choose pipeline partial deviations impact system Number k, coefficientoffrictionμ.

Prestress pipe coefficient of friction resistance method of testing the most according to claim 4, it is characterised in that step S4, In S5, the load on prestressing tendon (10) is according to 20%, and 40%, 60%, 80%, 100% point of Pyatyi loads.