CN102636501B - Filtering method for eliminating influences of surface reinforcing steel bars to high-frequency electromagnetic waves - Google Patents
Filtering method for eliminating influences of surface reinforcing steel bars to high-frequency electromagnetic waves Download PDFInfo
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- CN102636501B CN102636501B CN201210082795.6A CN201210082795A CN102636501B CN 102636501 B CN102636501 B CN 102636501B CN 201210082795 A CN201210082795 A CN 201210082795A CN 102636501 B CN102636501 B CN 102636501B
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Abstract
The invention discloses a filtering method for eliminating influences of surface reinforcing steel bars to high-frequency electromagnetic waves. The filtering method includes processing steps: (1) selecting measurement parameters and a detection mode; (2) selecting a reasonable energy window; (3) filtering the influences of the surface reinforcing steel bars; and (4) analyzing a filtering result and interpreting mud jacking defects. The filtering method for eliminating the influences of the surface reinforcing steel bars to the high-frequency electromagnetic waves in reinforced concrete detection has the advantages that the influences of strong reflection of the surface reinforcing steel bars can be basically suppressed, weak information reflected from deep defects can be strengthened, accordingly, the scale, the position and the types of the mud jacking defects can be more accurately judged, a reliable scientific theoretic basis is provided for engineering application, and the filtering method has an excellent application prospect and a practical significance.
Description
Technical field
The present invention relates to a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting.
Background technology
Post-tensioned prestressing concrete beam, owing to having the advantages such as span is long, lightweight, is widely used in recent years in bridge on highway construction.Prestressed concrete to have superiority be to be all based upon presstressed reinforcing steel and concrete coheres on intact basis; the Main Function of hole path pressure grouting is exactly for providing reliable cohesion between presstressed reinforcing steel and surrounding concrete; guarantee concrete and presstressed reinforcing steel collaborative work, transmit prestress and protect presstressed reinforcing steel to avoid corrosion.Owing to easily causing there is leakiness in corrugated tube at mud jacking technique and technical reason, make the local sheet cavity that occurs of mud jacking pipeline, presstressed reinforcing steel is invaded by air, water and other corrosive substance very easily, simultaneously, metal material is under high-stress state, corrosion rate is very fast, these factors all can impact the permanance of presstressed reinforcing steel structure, therefore, can the steel strand wires in Prestressed Concrete Bridges bring into play the effect of its effective prestress for a long time, and the grouting quality of corrugated tube and packing situation thereof are particularly crucial.
Pipeline pneumatic mortar technique is one concealed work in pre-stress construction, in construction, first the agent structure of the outer beam slab of corrugated tube is built complete, at beam body, reach the requirement of strength post-stress muscle of design code, finally preserved pipeline is carried out slip casting and completes the full rear end-blocking of mud jacking.The prestressed pore passage that mud jacking is full, can make presstressed reinforcing steel and its concrete coagulation around as a whole, and corresponding prestressing muscle plays a very good protection, and makes it avoid the erosion of outside air, water and other erosions.In practice of construction process, due to slurry injection technique and technological problems, cause the not full reason of reserving hole channel mud jacking a lot, corrugated pipe connector, middle part and lashing plug-hole etc. all do not make reserving hole channel slip casting full and form cavity, or due to water ash, proportioning is improper in pipeline, leaves cellular cavity after moisture is absorbed, and these cavities are to cause presstressed reinforcing steel corrosion or embroider disconnected main cause.Once presstressed reinforcing steel is destroyed, will affect permanance and the security of bridge, and, in the situation that squeezing quality exists defect, thereby can make concrete stress concentrate, the design stress of bridge is damaged, year in and year out, easily cause prestressed disappearance, and then affect serviceable life of bridge, therefore, it is imperative that the squeezing quality of prestress pipe is detected.But, for reinforced concrete quality testing, also there is no a kind of scientific and effective detection method, due to the complicacy of this body structure of prestressed girder, reason is that the processing mode of common engineering application can not meet the processing demands that reinforced concrete labyrinth is detected to data on the other hand on the one hand.Geological radar is in recent years emerging to utilize electromagnetic wave as the Dynamic Non-Destruction Measurement of detection means, due to its have lightweight, operation fast, the feature such as simple, reliable results, the application abroad of this technology is very extensive.China starts to introduce geological radar from the eighties in last century; be mainly used in seeking sources of water, underground mineral etc.; in recent years; start to be applied to engineering field and quality testing field, and obtained successful Application at the tunnel-liner of municipal works underground utilities, Rail Highway engineering and bridge pier thickness of concrete cover and reinforcement location, airfield runway and level ground, station disease.Because electromagnetic wave is more responsive to the water percentage of nonmetallic materials, make geological radar technology to concrete inner structure accurate imaging, therefore also can apply it to detection and the assessment aspect of prestress mud jacking duct quality.Nowadays; geological radar technology is very ripe aspect the detections such as concrete beam reinforcing skeletal distribution, protective layer thickness and presstressed reinforcing steel position; but due to the impact of the bar-mat reinforcement structure of dense distribution, the effect of the method in pumping of prostressed duct quality testing has been subject to very large constraint.This is because frequency electromagnetic waves is in Propagation process, its portion of energy is returned by the underground boundary reflection with electrical property difference, another part energy continues to propagate to depth direction, and the energy distribution of reflection and transmission is relevant with the electrical property difference situation at underground medium interface.Generally electrical property difference is larger, and the energy of reflection is larger, causes at the signal of deep propagation fainter.For geological radar short pulse frequency electromagnetic waves used, conventionally the medium running in engineering investigation and quality testing is all to take displacement current amount as main low loss dielectric, but when electromagnetic wave runs into take when conduction current is the medium of leading, will there is total reflection, make the energy energy very strong, transmission of reflection very faint.Take reinforced concrete structure as example, and xoncrete structure all can be considered low loss dielectric except reinforcing bar, and reinforcing bar is good conductor, is to take conduction current as main medium.While utilizing geological radar to detect pumping of prostressed duct quality, the electromagnetic wave signal that makes to propagate into prestress mud jacking pipeline due to the total reflection impact of top layer reinforcing bar is very faint, and this has increased the difficulty that squeezing quality is evaluated virtually.
Summary of the invention
Object of the present invention is exactly to detect in reinforced concrete Quality Process for applied geology radar method, the top layer reinforcing bar of xoncrete structure is very large still again less than well suppressing this deficiency to high-frequency electromagnetic wave action, proposing a kind of top layer reinforcing bar of rejecting affects electromagnetic wave, thereby is more prone to judge slip casting defective locations and big or small filtering method.
In order to realize above-mentioned technical purpose, technical scheme of the present invention is that a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting, comprises the steps:
(1) State selective measurements parameter and detection mode: use geological radar to carrying out data acquisition in concrete, the antenna box of geological radar is attached to concrete surface, and along the trend of concrete inner corrugated pipe, vertical direction in concrete is gathered;
(2) select rational energy window: will in gather raw data input matlab, form Visual Graph, determine that in the drawings near the maximal value of the amplitude of each root reinforcement location is as the summit (being the value of maximum data) of every reinforcing bar, take in the horizontal direction afterwards between the summit of every two reinforcing bars on Visual Graph is distance, comprised in vertical direction reinforcing bar for the first time, the data of secondary and triple reflection are that distance is carried out window selection, again the matrix data in all windows of selecting is added to summation, and then take number of windows as denominator, ask the mean value of matrix after above-mentioned summation, window after this weighted mean value obtaining is rational energy window,
(3) filtering top layer reinforcing bar impact: the maximum data value in energy window of take in step (2) after the peak swing value in selected each window and resulting weighting is corresponding reference point (peak swing value position and maximum data value position be the reinforcing bar summit in corresponding raw data and window data respectively), the matrix data of each selected each window is deducted respectively to the matrix data of the window after weighted mean value, obtain the data of filtering top layer reinforcing bar impact;
(4) analysis filtered effect interpretation mud jacking defect: the data of the filtering top layer reinforcing bar impact drawing in step (3) are analyzed with reference to the pre-buried degree of depth of steel strand wires in concrete, and the abnormal data figure that removes the rear gained of steel strand wires impact is inside concrete mud jacking problem.
The described a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting, in described step (1), the antenna of geological radar adopts the antenna of 1600MHz or 2600MHz frequency, and sampling number is 1024 or 2048.
The described a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting, in described step (4), finding out in step (3) other positions of the same degree of depth on the remarkable off-note in resulting data visualization figure and sectional view contrasts, if have obvious arc diffraction and reflection amplitude larger, according to steel strand wires projected depth, judge whether it is the impact of steel strand wires, if can be substantially identical with steel strand wires projected depth in the degree of depth and horizontal level, judge that this is the reflection of steel strand wires extremely, otherwise this is not the reflection of steel strand wires extremely; If out-of-the way position is steel strand wires impact, can get rid of it for mud jacking defect, if not the impact of reinforcing bar line, illustrate that mud jacking is not full, if got rid of after steel strand wires impact obviously abnormal without other again, for slip casting is closely knit.
In described reinforced concrete quality testing, reject the filtering method of top layer reinforcing bar high-frequency electromagnetic wave action, corrugated tube is nonmetallic mud jacking pipeline.
Advantage of the present invention is: adopt and in reinforced concrete quality testing of the present invention, reject the filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action, can substantially suppress the impact of top layer reinforcing bar strong reflection, strengthen deep defect reflection Weak Information out, thereby can judge more accurately scale, position and the defect type of mud jacking defect, for engineering application provides reliable scientific theory foundation, have a good application prospect and practical significance.
Below in conjunction with accompanying drawing, the invention will be further described.
Accompanying drawing explanation
Figure 1 shows that flow chart of steps of the present invention;
Fig. 2 is concrete model sectional schematic diagram;
Fig. 3 is the geological radar scanning section original graph of Fig. 2;
Fig. 4 is the enlarged drawing of the energy window selected in Fig. 3, is specially the maximal value of first and second reinforcing bar summit reflected energy;
Fig. 5 is for carrying out the filtering figure of Fig. 4 window to Fig. 3;
Fig. 6 is front certain track data figure of filtering in Fig. 3;
Fig. 7 is certain track data figure after filtering in Fig. 5.
Embodiment
The squeezing quality situation of disturbing the lower deep Weak Information gathering and judging prestress pipe in order to obtain clearly reinforcing bar, must choose suitable measurement parameter and metering system, comprise the arrangement of antenna dominant frequency size, metering system, acquisition mode and survey line etc.The selection of energy window is to reject the core of reinforcing bar to Electromagnetic Interference, and it plays a key effect to the filtration result disturbing, and the method realizes as follows:
The design of the selection of parameter and metering system, tender
The positional information of each defect and defect condition are to known tender and are defined as detected material, it is 2600MHz antenna that the present embodiment is selected dominant frequency, acquisition mode is some survey, point is apart from being made as 10mm, line direction moves towards direction perpendicular to corrugated tube, antenna is close to the surface of tender, and its long axis direction moves towards direction along survey line; Described tender top layer bar diameter is 20mm, degree of depth 100mm, and spacing 130mm, three objective bodies are respectively that slip casting is full, water-filling and cavity, and the degree of depth is 300mm left and right;
The selection of energy window
Select first reinforcing bar in the rear data of skew, choose a stationary window, this window has comprised the energy of bar one-time, secondary and triple reflection, select one little but substantially to have comprised that reinforcing bar energy is reflected into suitable as far as possible, described in Fig. 4, the window size of selection is 1101 (OK) * 13 (row);
Filtering method
Find the position on each reinforcing bar summit in reflection profile and select to ask for window data, the vertex position of reinforcing bar in the vertex position of reinforcing bar in raw data and window of take is corresponding reference point, the reflected energy of the reinforcing bar in raw data is deducted to the energy window that step (2) is selected, the reflection profile figure that affects of reinforcing bar that just filtering can have been obtained;
Filter effect Analysis and judgments
A. after filtering work completes, first-selected analysis filtered effect, if top layer reinforcing bar to affect filtration result poor, then repeating step 3, after filtering, deep out-of-the way position scope is take in the judge of effect has obvious anomalous reflection as standard;
B. find out raw data and become the remarkable off-note within the scope of figure, and with sectional view on other positions of the same degree of depth contrast, if there is obvious off-note, according to projected depth, judge whether it is the impact of steel strand wires; If steel strand wires impacts, it is defect can to get rid of mud jacking, if not the impact of reinforcing bar line, illustrates that mud jacking is not full, if got rid of after steel strand wires impact obviously abnormal without other again, for slip casting is closely knit;
Utilize and in reinforced concrete quality testing of the present invention, reject top layer reinforcing bar when the filtering method of high-frequency electromagnetic wave action is verified to filter effect, can be undertaken by following detailed implementation step, its steps flow chart as shown in Figure 1.
Embodiment 1:
This routine reinforced concrete test specimen section size is 310mm * 60mm, as shown in Figure 2, in Fig. 2, have two placing of reinforcements 1, being distributed in respectively concrete is all the top layer of 100mm apart from top and the bottom of test specimen, and bar diameter is 20mm, spacing is 130mm, presstressed reinforcing steel 2 diameters are 50mm, and mud jacking is closely knit grout 3, and water-filling 4 and cavity 5 are all positioned at corrugated tube top, thickness 20mm, corrugated tube tube wall 2mm.
In detection, antenna trend is moved towards position perpendicular to corrugated tube, adopts point apart from metering system, and point, apart from being 10mm, obtains the original reflection of electromagnetic wave section of Fig. 3.Select the position of first reinforcing bar pole of sectional view mesexine, and find out secondary reflection summit, but select the little window that can comprise again and secondary reflection energy of trying one's best, according to Fig. 3, window size can be chosen as 1101 (OK) * 13 (row), after amplification, as shown in Figure 4, this energy window almost can be thought whole energy of reinforcing bar reflection.
Find the vertex position of all reinforcing bar reflection electromagnetic waves in reflection profile, and to take energy window and other reinforcing bar pole be corresponding reference point, deduct successively the reflected energy of window reinforcing bar, complete filtering analysis filtered effect, finally obtain reflection profile as shown in Figure 5.Known by the analysis to Fig. 5, this filtering method has been rejected the impact of top layer reinforcing bar total reflection substantially, by extracting the information in the reflection profile Zhong Mou road of filtering method front and back, obtain respectively Fig. 6 and Fig. 7, in Fig. 6, the amplitude of position shown in 6 is large, in Fig. 7, same depth location place amplitude is little, reflection of electromagnetic wave amplitude by the strong reflection of reinforcing bar on front and back contrast discovery single track reflection wave has obtained good compacting, and the reflection amplitude in deep has obtained obvious enhancing.By this method filtering, reinforced concrete deep originally faint information has obtained obvious lifting, and this grouting quality evaluation for prestress mud jacking duct has very significance.
The present invention can also have other processing mode, and the treatment scheme that the equal mode of all employings or equivalent transformation form, all drops in claimed scope of the present invention.
Claims (3)
1. reject the filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action, it is characterized in that, comprise the steps:
(1) State selective measurements parameter and detection mode: use geological radar to carrying out data acquisition in concrete, the antenna box of geological radar is attached to concrete surface, and along the trend of concrete inner corrugated pipe, vertical direction in concrete is gathered, the antenna of geological radar adopts the antenna of 1600MHz or 2600MHz frequency, and sampling number is 1024 or 2048;
(2) select rational energy window: will in gather raw data input matlab, form Visual Graph, determine that in the drawings near the maximal value of the amplitude of each root reinforcement location is as the summit of every reinforcing bar, take in the horizontal direction afterwards between the summit of every two reinforcing bars on Visual Graph is distance, comprised in vertical direction reinforcing bar for the first time, the data of secondary and triple reflection are that distance is carried out window selection, again the matrix data in all windows of selecting is added to summation, and then take number of windows as denominator, ask the mean value of matrix after above-mentioned summation, window after this weighted mean value obtaining is rational energy window,
(3) filtering top layer reinforcing bar impact: the maximum data value in energy window of take in step (2) after the peak swing value in selected each window and resulting weighting is corresponding reference point, the matrix data of each selected each window is deducted respectively to the matrix data of the window after weighted mean value, obtain the data visualization figure of filtering top layer reinforcing bar impact;
(4) analysis filtered effect interpretation mud jacking defect: the data of the filtering top layer reinforcing bar impact drawing in step (3) are analyzed with reference to the pre-buried degree of depth of steel strand wires in concrete, and the abnormal data figure that removes the rear gained of steel strand wires impact is inside concrete mud jacking problem.
2. a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting according to claim 1, it is characterized in that, in described step (4), finding out resulting data in step (3) becomes other positions of the same degree of depth on remarkable off-note in figure and sectional view to contrast, if have obvious arc diffraction and reflection amplitude larger, according to steel strand wires projected depth, judge whether it is the impact of steel strand wires, if can be substantially identical with steel strand wires projected depth in the degree of depth and horizontal level, judge that this is the reflection of steel strand wires extremely, otherwise, this is not the reflection of steel strand wires extremely, if out-of-the way position is steel strand wires impact, can get rid of it for mud jacking defect, if not the impact of steel strand wires, illustrate that mud jacking is not full, if got rid of after steel strand wires impact obviously abnormal without other again, for slip casting is closely knit.
3. a kind of filtering method of top layer reinforcing bar to high-frequency electromagnetic wave action of rejecting according to claim 1, is characterized in that: corrugated tube is nonmetallic mud jacking pipeline.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104849290B (en) * | 2015-06-11 | 2017-07-04 | 四川大学 | Three-dimensional concrete health detecting method and its detection circuit based on reinforcing bar antenna |
| RU2737415C1 (en) * | 2017-03-10 | 2020-11-30 | Просек Са | Concrete construction probing using electromagnetic waves |
| RU2736105C1 (en) * | 2019-08-02 | 2020-11-11 | Федеральное государственное бюджетное учреждение науки Институт проблем управления им. В.А. Трапезникова Российской академии наук | Method of location control of reinforcement in a reinforced concrete article |
| CN111856454A (en) * | 2020-08-11 | 2020-10-30 | 湖南致力工程科技有限公司 | Bridge prestressed plastic duct grouting plumpness detection method |
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| EP2244101A1 (en) * | 2008-01-04 | 2010-10-27 | Pontificia Universidad Catolica de Chile | System and method for detecting, locating and identifying objects located above ground or below ground in a pre-referenced area of interest |
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