CN100510269C - Dike piping detecting method - Google Patents

Abstract

The invention discloses a detection method for dam piping, comprising that water temperature and air temperature are measured and dam soil type is examined; the dam is scanned by infrared hot-wire instrument to obtain isothermal line distribution of dam surface and find points where temperature is different from peripheral circumstance in evidence; the distribution picture of points where temperature is different from peripheral circumstance and adjacent temperature gradient is drawn and when radial temperature gradient value is larger than the critical value, detecting point mentioned above is determined as piping occurring position. Compared with prior detection method the invention is simpler and more reliable and piping can be found before dam piping transfixion so that there is enough time to carry prevention measure out in advance.

Description

A kind of dike piping detecting method

Technical field

The present invention relates to a kind of dike piping detecting method.

Background technology

The dykes and dams generation piping in rivers, lake is a key factor that causes dykes and dams to damage, and for preventing the generation of this class disaster, dykes and dams is detected being very important with effective prevention piping in advance.At present very immature about the method for discrimination of piping positions and possibility occurrence, could find its particular location after generally will waiting until full perforation, at this moment usually late.

Summary of the invention

At the problems referred to above, the object of the present invention is to provide a kind of easy reliable, predictable dike piping detecting method.

For achieving the above object, the inventor has proposed a kind of piping based on infrared hot line instrument and has surveyed new method, infrared hot line instrument can be told the temperature difference of 0.1C, and the passage front end soil body temperature of piping may take place, because the notable difference (especially between round the clock) of water temperature and soil body temperature has notable difference than the surrounding soil temperature.Based on this principle, as long as we detect the place that has this species diversity with infrared hot line instrument, just can determine the position of piping.

Detailed process is that a kind of dike piping detecting method may further comprise the steps:

(1) measuring water temperature, atmospheric temperature, check dykes and dams soil body type;

(2) with infrared hot line instrument dykes and dams are scanned, obtain the Isothermal Line Distribution on dykes and dams surface, find out temperature and visibly different point on every side;

(3) draw said temperature and obvious difference and near temperature gradient distribution figure on every side, try to achieve temperature gradient value by following formula,

$T_d=\frac{\∂T(r,\mathrm{\θ})}{\∂r}$

T _dBe radial symmetry gradient, T (r, θ) be the absolute temperature of body surface, r is that radial coordinate, θ are the hoop coordinate, the temperature value that deducts this point by the temperature value of the neighbor point of this radially outside point obtains the temperature gap between 2, promptly obtains radial symmetry gradient T with this temperature gap divided by the distance of point-to-point transmission then _d, as radial symmetry gradient T _dT _rThe time, T _rBe the threshold of the radial symmetry gradient of piping positions, can determine that above-mentioned test point is the piping occurrence positions.

In described step (three), the threshold of described radial symmetry gradient is obtained by experiment, at first fetch the soil body of dykes and dams to be detected and make indoor dykes and dams mini Mod, manual simulation's several times finally have piping to form and do not have the process that piping forms in advance on the dykes and dams mini Mod, with the dykes and dams mini Mod surface temperature change procedure in the infrared hot line instrument measure analog process, obtain the gradient of model surface temperature, the temperature gradient that relatively has or not piping to form is determined the threshold of radial symmetry gradient.

The more present detection method of said method is easier to be reliable, and can find before dike piping connects, thereby takes prophylactico-therapeutic measures if having time in advance, reduces loss.

Description of drawings

Fig. 1-Fig. 3 is respectively the temperature of different time dike piping position and contrast figure on every side.

The specific embodiment

Dike piping detecting method of the present invention may further comprise the steps:

(1) measuring water temperature, atmospheric temperature, check dykes and dams soil body type;

(2) with infrared hot line instrument dykes and dams are scanned, obtain the Isothermal Line Distribution on dykes and dams surface, find out temperature and visibly different place on every side;

(3) according to test and result of theoretic analysis, promptly according to water temperature, atmospheric temperature, the soil body type measured, by the discrimination formula that test and theoretical analysis result obtain, differentiate whether the place that obvious temperature contrast is arranged is piping possibility scene, it is as follows specifically to differentiate process:

The ir radiant power of general object can be expressed as: W=ε σ T ⁴24 ℃≤T≤35 ℃

Wherein ε is an emissivity, σ is the Si Difen Boltzmann constant, T is the absolute temperature of body surface, after the ultrared power transfer of utilizing infrared hot line detector that body surface is given off becomes the signal of telecommunication, just can obtain the Temperature Distribution of body surface by imaging device, thereby obtain the temperature gradient distribution figure of body surface.The passage of piping is generally the pipe shape, analyzed area can be arranged in the cylindrical coordinate, and we distribute according to the gradient of temperature, just can determine interior of articles unusual may be the position of piping:

The temperature gradient is tried to achieve by following formula:

$T_d=\frac{\∂T(r,\mathrm{\θ})}{\∂r};$ 1：T _d＝4；2：T _d＝1；3：T _d＝0.1

T _dBe radial symmetry gradient, (r θ) is the absolute temperature of body surface to T, and this temperature value is directly recorded by infrared hot line instrument, and r is that radial coordinate, θ are the hoop coordinate, asks certain some radial symmetry gradient T _dThe time, the temperature value that deducts this point by the temperature value of the neighbor point of this radially outside point obtains the temperature gap between 2, promptly obtains radial symmetry gradient T with this temperature gap divided by the distance of point-to-point transmission then _d

Obtain radial symmetry gradient T _dAfter, work as T _dT _rThe time, can determine that above-mentioned test point is piping occurrence positions, wherein T _rBe the threshold of the radial symmetry gradient of piping positions, this value is generally obtained by experiment by the decision of factors such as soil body type, environment temperature, water temperature.Head fetches the soil body of dykes and dams to be detected and makes indoor dykes and dams mini Mod, manual simulation's several times finally have piping to form and do not have the process that piping forms in advance on the dykes and dams mini Mod, measure model surface temperature changing process in these processes with infrared hot line instrument, obtain the gradient of model surface temperature, the temperature gradient that relatively has or not piping to form just can be determined T _r

Be result of the test below: shown in the temperature of Fig. 1,2,3 different time piping positions and contrast figure on every side, the soil body temperature at piping positions place is with obviously different on every side, and this place's temperature is consistent with water temperature gradually in time, and the surrounding soil temperature is constant substantially.

Claims (2)

1, a kind of dike piping detecting method may further comprise the steps:

(1) measuring water temperature, atmospheric temperature, check dykes and dams soil body type;

(2) with infrared hot line instrument dykes and dams are scanned, obtain the Isothermal Line Distribution on dykes and dams surface, find out temperature and visibly different point on every side;

(3) draw said temperature and obvious difference and near temperature gradient distribution figure on every side, try to achieve temperature gradient value by following formula,

$T_d=\frac{\∂T(r,\mathrm{\θ})}{\∂r}$

T _dBe radial symmetry gradient, T (r, θ) be the absolute temperature of body surface, r is that radial coordinate, θ are the hoop coordinate, the temperature value that deducts this point by the temperature value of the neighbor point of this radially outside point obtains the temperature gap between 2, promptly obtains radial symmetry gradient T with this temperature gap divided by the distance of point-to-point transmission then _d, as radial symmetry gradient T _dT _rThe time, T _rBe the threshold of the radial symmetry gradient of piping positions, can determine that above-mentioned test point is the piping occurrence positions.

2, dike piping detecting method as claimed in claim 1, it is characterized in that, the threshold of described radial symmetry gradient is obtained by experiment, at first fetch the soil body of dykes and dams to be detected and make indoor dykes and dams mini Mod, manual simulation's several times finally have piping to form and do not have the process that piping forms in advance on the dykes and dams mini Mod, with the dykes and dams mini Mod surface temperature change procedure in the infrared hot line instrument measure analog process, obtain the gradient of model surface temperature, the temperature gradient that relatively has or not piping to form is determined the threshold of radial symmetry gradient.

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