CN108828678A - A kind of advanced geology for tunnel construction detection system - Google Patents
A kind of advanced geology for tunnel construction detection system Download PDFInfo
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- CN108828678A CN108828678A CN201810976081.7A CN201810976081A CN108828678A CN 108828678 A CN108828678 A CN 108828678A CN 201810976081 A CN201810976081 A CN 201810976081A CN 108828678 A CN108828678 A CN 108828678A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
- G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
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Abstract
A kind of advanced geology for tunnel construction detection system, including：Power supply positive electrode, is arranged on TBM construction machinery；Detection electrode is set on first movement channel, can be advanced along the motion channel with tunnel piercing direction；Power supply negative electrode, is set on the second motion channel, can advance along second motion channel with tunnel piercing direction；Data acquisition module is used to acquire the signal of detection electrode；The data-signal of acquisition is transmitted to data processing host by communication module；Data processing host determines constructing tunnel front geological condition according to the data-signal that communication module transmits.Advanced prediction and identification can be carried out containing permeable structure to tunnel tunnel face front fault belt, solution cavity etc. through the invention, ensure constructing tunnel building security.
Description
Technical field
The present invention relates to geo-detection systems, detect in the process to the aqueous situation in front more particularly, to constructing tunnel
Advance geology exploration system.
Background technique
With domestic highway, railway, water conservancy, mine and the rapid development of other engineering constructions, Tunnel Engineering is also measured greatly
It is existing.Since with a varied topography, edpth of tunnel is big, earth's surface exploratory techniques are limited before constructing tunnel, surveying the stage on ground cannot all be investigated thoroughly
Adverse geological condition along the line, construction time advanced prediction method fail to make water-bearing structure effective forecast.In constructing tunnel mistake
Cheng Zhong, often because the natural calamities such as landslide, water burst occurs in geological problem.Therefore, carry out and be directed to tunnel tunnel face front fault disruption zone
The advanced predictions containing permeable structure such as band, solution cavity and quantitative judge are studied, and are the urgent need for ensureing constructing tunnel building security, tool
There are great theory significance and engineering value.
It is seismic wave method, geological radar method, red currently, have a geological analysis method using more in tunnel forward probe field
Outer spy water law etc., these methods have respective advantage and deficiency.Geological analysis method passes through the engineering geology in earth's surface and tunnel
Investigation and analysis, infer the geological condition in front, have very high standard in the case where edpth of tunnel is shallower, construction is less complicated
True property, but the precision of its forecast result under complex geological condition is difficult to ensure.Seismic wave method is in forecast front of tunnel heading rock
Property variation and major fault in terms of have a preferable effect, but its observed pattern is straight line survey line mode, it is difficult to before obtaining face
The wave speed distribution of side, can not forecast with the small angle tomography of tunnel axis, and cannot forecast water body in front of tunnel.Geological radar method tool
Have differentiate high, not damaged, detection and data processing fastly, the feature of maneuverability, but its is maximum the disadvantage is that scope can be forecast
It is smaller, it can only control in 30m.Infrared water detecting method crosses thermo parameters method in measurement analysis tunnel and differentiates water content, is only capable of
To whether there is or not water contents to do qualitative forecast in front of tunnel heading a certain range, it is difficult to be positioned.
Electrical prospecting is to detect the geological conditions such as formation lithology, geological structure by studying and observing the variation of electric current
Exploitation method.Induced polarization method is a kind of geophysical exploration method of electrical prospecting, with the sharp electricity between different geologic mediums
Parameter differences are material base, can be with parameters such as measured resistivity, polarizability, half decay time, the doughs softening, wherein resistance parameter pair
Water body response is sensitive, and half decay time characterizes induced polarization dampening information, and there are certain relationships with water body water.By to induced polarization
The parameters such as difference of polarizability, resistivity and half decay time carry out analysis and inverting in method, available front of tunnel heading rock mass
Resistivity, polarizability structure provide important reference to carry out advance geologic prediction.In the prior art, super in induced polarization method
When preceding detection, usually power supply positive electrode is set on road heading machinery, measuring electrode is set to tunnel-side, and power supply negative electrode is set
It is placed in tunnel rear infinite point, is from flow direction power supply negative electrode in front of power supply positive electrode, due to development machine on excitation current
Tool electromagnetic environment itself is extremely complex, can generate electromagnetic interference, influence detection result；Meanwhile with the advance of road heading machinery,
Measuring electrode generates variation at a distance from current electrode, and the resistivity as caused by distance change and polarizability variation can be for
The resistivity as caused by geo-environmental change and polarizability variation generate interference.
Summary of the invention
The present invention provides a kind of advanced geology for tunnel construction detection system, is able to solve the above problem of the prior art.
As one aspect of the present invention, a kind of advanced geology for tunnel construction detection system is provided, including：Power supply positive electricity
Pole is arranged on TBM construction machinery；First movement channel is set to the overhead surface of constructing tunnel direction front of tunnel heading
Soil layer is arranged along tunnel piercing direction；Detection electrode is set on the first movement channel, can be along the shifting
Dynamic channel is with the advance of tunnel piercing direction；Second motion channel is set to the first movement along tunnel piercing direction
In front of channel；Power supply negative electrode, is set on second motion channel, can be along second motion channel with tunnel
Road tunneling direction advances；Data acquisition module is connected with the detection electrode, for acquiring the signal of the detection electrode；
The data-signal of data collecting module collected is transmitted to data processing host by communication module；Data processing host, basis
The data-signal of communication module transmission, determines constructing tunnel front geological condition.
Further, the detection electrode is unpolarizable electrode.
Further, the power supply positive electrode is set in front of TBM construction machinery.
Further, the communication module is wireless communication module or wire communication module.
Further, the detection electrode is "T"-shaped, and its underpart is located in the first movement channel.
Further, the power supply negative electricity is extremely "T"-shaped, and its underpart is located in second motion channel.
Further, the detection electrode includes more electrodes of different location.
Further, when tunnel piercing detects, by mobile device by the detection electrode and the TBM construction machinery
Identical speed is moved along the first movement channel, while the power supply negative electrode is identical with the TBM construction machinery
Speed is moved along the second motion channel.
Further, the data processing host is according to the variation of the current signal of the detection electrode, before determining tunnel
Square geologic body assigns regimen condition.
Further, the depth of the first movement channel is greater than the second motion channel.
Further, data processing host determines ground in front of tunnel according to the variation of the current signal of the detection electrode
Plastid assigns regimen condition.
Detailed description of the invention
Fig. 1 is a kind of setting schematic diagram of advanced geology for tunnel construction detection system of the embodiment of the present invention.
Specific embodiment
The embodiment of the present invention is described below in detail, examples of the embodiments are shown in the accompanying drawings, wherein from beginning to end
Same or similar label indicates same or similar element or element with the same or similar functions.Below with reference to attached
The embodiment of figure description is exemplary, and for explaining only the invention, and is not considered as limiting the invention.Moreover, answering
Work as understanding, the feature not mutual exclusion of various embodiments described herein, and can be combined and transformation mistake various
Exist in journey.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the scope of the present invention.
Referring to Fig. 1, the advanced geology for tunnel construction detection system of the embodiment of the present invention is used for tunnel construction process
In, geological conditions near face is prejudged, including power supply positive electrode 10, detection electrode 20, negative electrode 30 of powering, first
Motion channel 40, the second motion channel 50, data acquisition module 60, communication module 70 and data processing host 80.
Power supply positive electrode 10 is metal electrode, is connect with DC power supply, focuses forward probe current for providing.Power supply
Positive electrode 10 can be annular electrode, be set in front of TBM construction machinery, along tunnel piercing side during constructing tunnel
Method is advanced.
Along the tunneling direction in tunnel, first movement channel 40 is set in the layer of ground soil of tunnel upper.Detection electrode 20
For acquire induced polarization generation electric current or voltage signal, be set on first movement channel 40, detection electrode 20 with
The distance of tunnel tunnel face can be such as 50 ~ 100m.Detection electrode 20 can be for example T-shaped, pass through mobile device example
As trolley can be such that detection electrode 20 moves with the identical speed of TBM construction machinery along first movement channel 40.Detection electrode 20
For unpolarizable electrode, one or more detection electrode can be set in first movement channel 40.
Second motion channel 50 is set to 40 front of first movement channel along tunnel piercing direction, can be mobile by second
The depth of channel 50 is set smaller than first movement channel 40.Power supply negative electrode 30 is metal electrode, and one end is set to second
On motion channel 50, the other end is connected by conducting wire with power cathode.Powering negative electrode 30 can be at a distance from tunnel tunnel face
It is such as 100 ~ 150m.Power supply negative electrode 30 is also possible to for example T-shaped, can make to supply by mobile device such as trolley
Electric negative electrode 30 is moved with the identical speed of TBM construction machinery along the second motion channel 50.
Data acquisition module 60 is connected with detection electrode 20, for acquiring the signal of detection electrode 20.Communication module 70 will
The data-signal that data acquisition module 60 acquires is transmitted to data processing host 80, and communication module 70 can be wireless communication module
Or wire communication module.Data processing host 80 determines the view electricity of tunnel tunnel face front according to the detectable signal received
Resistance rate and apparent chargeability indicate that front rock mass water content increases when front rock mass apparent resistivity reduces, and apparent chargeability increases,
Indicate that the front rock mass property of water-bearing is weak when front rock mass apparent resistivity height, when apparent chargeability is low.
In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, term " installation ", " phase
Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected；It can
To be mechanical connection, it is also possible to be electrically connected；It can be directly connected, can also can be indirectly connected through an intermediary
Connection inside two elements.For the ordinary skill in the art, above-mentioned term can be understood at this with concrete condition
Concrete meaning in invention.Herein, relational terms such as first and second and the like be used merely to an entity or
Person's operation is distinguished with another entity or operation, is appointed without necessarily requiring or implying existing between these entities or operation
What this actual relationship or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to non-row
His property includes, so that the process, method, article or equipment for including a series of elements not only includes those elements, and
And further include other elements that are not explicitly listed, or further include for this process, method, article or equipment institute it is intrinsic
Element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that including institute
State in the process, method, article or equipment of element that there is also other identical elements.
The above is only the preferred embodiment of the present invention, protection scope of the present invention is not limited merely to above-described embodiment,
All technical solutions belonged under thinking of the present invention all belong to the scope of protection of the present invention.For the ordinary skill people of the art
For member, several improvements and modifications without departing from the principles of the present invention should be regarded as falling into protection scope of the present invention.
Claims (10)
1. a kind of advanced geology for tunnel construction detection system, including：Power supply positive electrode, is arranged on TBM construction machinery；First moves
Dynamic channel, is set to the overhead surface soil layer of constructing tunnel direction front of tunnel heading, is arranged along tunnel piercing direction；Detection
Electrode is set on the first movement channel, can be advanced along the motion channel with tunnel piercing direction；Second
Motion channel is set in front of the first movement channel along tunnel piercing direction；Power supply negative electrode is set to described
On second motion channel, it can advance along second motion channel with tunnel piercing direction；Data acquisition module, with
The detection electrode is connected, for acquiring the signal of the detection electrode；Communication module, by the number of data collecting module collected
It is believed that number being transmitted to data processing host；Data processing host determines that tunnel is applied according to the data-signal that communication module transmits
Work front geological condition.
2. advanced geology for tunnel construction detection system according to claim 1, it is characterised in that：The detection electrode is not
Polarizing electrode.
3. advanced geology for tunnel construction detection system according to claim 2, it is characterised in that：The detection electrode includes
More electrodes of different location.
4. advanced geology for tunnel construction detection system according to claim 3, it is characterised in that：The power supply positive electricity is extremely
Metal electrode.
5. advanced geology for tunnel construction detection system according to claim 4, it is characterised in that：The power supply negative electricity is extremely
Metal electrode.
6. advanced geology for tunnel construction detection system according to claim 5, it is characterised in that：The power supply positive electrode is set
It is placed in front of TBM construction machinery.
7. advanced geology for tunnel construction detection system according to claim 6, it is characterised in that：The communication module is nothing
Line communication module or wire communication module etc..
8. advanced geology for tunnel construction detection system according to claim 7, it is characterised in that：The detection electrode is
"T"-shaped, its underpart is located in the first movement channel.
9. advanced geology for tunnel construction detection system according to claim 8, it is characterised in that：The power supply negative electricity is extremely
"T"-shaped, its underpart is located in second motion channel.
10. advanced geology for tunnel construction detection system according to claim 9, it is characterised in that：The data processing master
Machine determines that tunnel front geological body assigns regimen condition according to the variation of the current signal of the detection electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810976081.7A CN108828678B (en) | 2018-08-25 | 2018-08-25 | Advanced geological detection system for tunnel construction |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810976081.7A CN108828678B (en) | 2018-08-25 | 2018-08-25 | Advanced geological detection system for tunnel construction |
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| Publication Number | Publication Date |
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| CN108828678A true CN108828678A (en) | 2018-11-16 |
| CN108828678B CN108828678B (en) | 2020-05-29 |
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| CN201810976081.7A Expired - Fee Related CN108828678B (en) | 2018-08-25 | 2018-08-25 | Advanced geological detection system for tunnel construction |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112255691A (en) * | 2020-11-09 | 2021-01-22 | 高军 | Method for detecting deep fracture geology by induced polarization composite frequency |
| WO2021146949A1 (en) * | 2020-01-20 | 2021-07-29 | 山东大学 | Tbm-mounted rock alteration feature identification and geological prediction system and method therefor |
| CN113309506A (en) * | 2021-05-18 | 2021-08-27 | 山东大学 | Advanced observation method and device based on electric dipole emission in hole |
| CN117270062A (en) * | 2023-11-22 | 2023-12-22 | 山东大学 | TBM induced polarization advanced water detection device and method based on annular electrode emission |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101706585A (en) * | 2009-10-28 | 2010-05-12 | 中南大学 | Method for electrically forecasting danger in underground tunneling engineering |
| CN102156301A (en) * | 2011-03-23 | 2011-08-17 | 中南大学 | Advanced-prediction observation system while drilling |
| CN102236105A (en) * | 2010-04-23 | 2011-11-09 | 林希仲 | Omnibearing direct current method |
| US20120139542A1 (en) * | 2010-12-02 | 2012-06-07 | Willowstick Technologies, Llc | Subsurface water channel detection |
| CN103576207A (en) * | 2012-07-27 | 2014-02-12 | 韩国地质资源研究院 | Non-polarizable probe and spectral induced polarization logging device including the same |
| CN103645514A (en) * | 2013-12-25 | 2014-03-19 | 山东大学 | Underground engineering advanced detection method and system for resistivity of multi-same-source electrode array |
| CN103995295A (en) * | 2014-06-11 | 2014-08-20 | 中煤科工集团西安研究院有限公司 | Direct current electric method ground hole detection method and device |
| CN104007472A (en) * | 2014-06-11 | 2014-08-27 | 中煤科工集团西安研究院有限公司 | In-hole direct current electric method advanced detection method |
| CN105738955A (en) * | 2014-12-11 | 2016-07-06 | 安徽惠洲地质安全研究院股份有限公司 | Direct-current-electric-method-based rapid electrode distribution system for advanced detection of water hazard in tunnel and detection method thereof |
| CN106772621A (en) * | 2017-01-24 | 2017-05-31 | 山东大学 | A kind of nearly comprehensive resistivity geological extra-forecast method |
-
2018
- 2018-08-25 CN CN201810976081.7A patent/CN108828678B/en not_active Expired - Fee Related
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101706585A (en) * | 2009-10-28 | 2010-05-12 | 中南大学 | Method for electrically forecasting danger in underground tunneling engineering |
| CN102236105A (en) * | 2010-04-23 | 2011-11-09 | 林希仲 | Omnibearing direct current method |
| US20120139542A1 (en) * | 2010-12-02 | 2012-06-07 | Willowstick Technologies, Llc | Subsurface water channel detection |
| CN102156301A (en) * | 2011-03-23 | 2011-08-17 | 中南大学 | Advanced-prediction observation system while drilling |
| CN103576207A (en) * | 2012-07-27 | 2014-02-12 | 韩国地质资源研究院 | Non-polarizable probe and spectral induced polarization logging device including the same |
| CN103645514A (en) * | 2013-12-25 | 2014-03-19 | 山东大学 | Underground engineering advanced detection method and system for resistivity of multi-same-source electrode array |
| CN103995295A (en) * | 2014-06-11 | 2014-08-20 | 中煤科工集团西安研究院有限公司 | Direct current electric method ground hole detection method and device |
| CN104007472A (en) * | 2014-06-11 | 2014-08-27 | 中煤科工集团西安研究院有限公司 | In-hole direct current electric method advanced detection method |
| CN105738955A (en) * | 2014-12-11 | 2016-07-06 | 安徽惠洲地质安全研究院股份有限公司 | Direct-current-electric-method-based rapid electrode distribution system for advanced detection of water hazard in tunnel and detection method thereof |
| CN106772621A (en) * | 2017-01-24 | 2017-05-31 | 山东大学 | A kind of nearly comprehensive resistivity geological extra-forecast method |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2021146949A1 (en) * | 2020-01-20 | 2021-07-29 | 山东大学 | Tbm-mounted rock alteration feature identification and geological prediction system and method therefor |
| CN112255691A (en) * | 2020-11-09 | 2021-01-22 | 高军 | Method for detecting deep fracture geology by induced polarization composite frequency |
| CN112255691B (en) * | 2020-11-09 | 2024-02-02 | 高军 | Deep fracture geological method for detecting excitation composite frequency |
| CN113309506A (en) * | 2021-05-18 | 2021-08-27 | 山东大学 | Advanced observation method and device based on electric dipole emission in hole |
| CN117270062A (en) * | 2023-11-22 | 2023-12-22 | 山东大学 | TBM induced polarization advanced water detection device and method based on annular electrode emission |
| CN117270062B (en) * | 2023-11-22 | 2024-02-09 | 山东大学 | TBM induced polarization advanced water detection device and method based on annular electrode emission |
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