CN111395297A - CPTU device applying optical fiber technology in shallow sea geology - Google Patents
CPTU device applying optical fiber technology in shallow sea geology Download PDFInfo
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- CN111395297A CN111395297A CN202010284121.9A CN202010284121A CN111395297A CN 111395297 A CN111395297 A CN 111395297A CN 202010284121 A CN202010284121 A CN 202010284121A CN 111395297 A CN111395297 A CN 111395297A
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- optical fiber
- cptu
- probe
- sleeve
- time domain
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D1/00—Investigation of foundation soil in situ
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D1/00—Investigation of foundation soil in situ
- E02D1/02—Investigation of foundation soil in situ before construction work
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D1/00—Investigation of foundation soil in situ
- E02D1/02—Investigation of foundation soil in situ before construction work
- E02D1/022—Investigation of foundation soil in situ before construction work by investigating mechanical properties of the soil
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Soil Sciences (AREA)
- Analytical Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Testing Or Calibration Of Command Recording Devices (AREA)
- Optical Transform (AREA)
Abstract
The invention aims to provide a CPTU device applying an optical fiber technology in shallow sea geology, so as to solve the problems that the measurement precision is poor and the measurement equipment is easily interfered by the environment in the prior art. The technical scheme of the invention is as follows: a CPTU device applying an optical fiber technology in shallow sea geology is characterized by comprising a CPTU probe, an optical fiber, a probe rod, a sealing sleeve, a Brillouin optical time domain reflectometer, a network cable and a computer; the sealing sleeve is of a hollow tubular structure; the sealing sleeve is connected to one end of the CPTU in a sealing mode, and the other end of the sealing sleeve is connected to one end of the Brillouin optical time domain reflectometer; the optical fiber is arranged in the sealed sleeve, and the Brillouin optical time domain reflectometer is connected with a computer through a network cable. The method is mainly used for measuring parameters such as shallow sea geological cone tip resistance, side wall friction resistance, pore water pressure and the like.
Description
Technical Field
The invention relates to a CPTU device applying an optical fiber technology in shallow sea geology, and belongs to the technical field of ocean observation and the field of optical fiber application.
Background
The marine geological exploration aims at exploring marine geological conditions, explaining soil body types, determining soil body properties and the like, so that reliable and accurate exploration data are provided for marine engineering construction, accurate reference is provided for determining a construction scheme, and the marine geological exploration is an essential link in marine engineering. In terms of the current situation, marine geological exploration measures are abundant and various, and mainly include engineering geophysical prospecting, radar detection, in-situ testing, on-site drilling sampling and the like. The in-situ test is taken as a survey means for directly reflecting the properties of the soil body, and has the advantages of high accuracy, strong reference and the like.
The hydrostatic penetration test (CPTU) is an important in-situ test technique in the field of geotechnical engineering, and measures parameters such as cone tip resistance, side wall friction resistance, pore water pressure and the like through continuous penetration of a probe in soil, and the parameters can reflect the physical and mechanical properties of a soil body. The accuracy of layering of the soil layer is determined by the measurement accuracy of various parameters of the probe. Therefore, the method for improving the measurement precision of the multifunctional piezocone penetration test has important theoretical significance and engineering application value.
The optical fiber sensing technology is a new sensing technology which takes light as a carrier and optical fiber as a medium to sense and transmit an external signal (to be measured) and is rapidly developed in the 80 th century along with the development of optical fiber and optical fiber communication technology. Brillouin optical time domain reflectometer (BOTDR for short) is a novel photoelectric sensing monitoring technology which is developed in recent years internationally.
In the prior art, the CPTU has complicated internal components, a resistance-type sensor is often adopted, and the measurement precision is poor; the data transmission uses cable transmission, and is easily influenced by environment and distance, especially in severe environments such as ocean. Obviously, for complex and various marine environments, how to obtain more accurate measurement data and how to effectively protect test equipment is a problem to be solved urgently at present.
Disclosure of Invention
The invention aims to provide a CPTU device applying an optical fiber technology in shallow sea geology, so as to solve the problems that the measurement precision is poor and the measurement equipment is easily interfered by the environment in the prior art.
The technical scheme for solving the technical problems is as follows:
a CPTU device applying an optical fiber technology in shallow sea geology is characterized by comprising a CPTU probe, an optical fiber, a probe rod, a sealing sleeve, a Brillouin optical time domain reflectometer, a network cable and a computer; the sealing sleeve is of a hollow tubular structure; the sealing sleeve is connected to one end of the CPTU in a sealing mode, and the other end of the sealing sleeve is connected to one end of the Brillouin optical time domain reflectometer; the optical fiber is arranged in the sealed sleeve, and the Brillouin optical time domain reflectometer is connected with a computer through a network cable.
The Brillouin optical time domain reflectometer utilizes a GPIB communication interface and a network
The interface realizes the communication with the computer through the network cable.
The CPTU probe is formed by sequentially connecting a probe rod, a friction sleeve and a probe, wherein the probe rod is connected with the friction sleeve through a pressure rod connector, a soil body sealing ring is arranged between the friction sleeve and the probe, the soil body sealing ring is arranged between the friction sleeve and the probe, a signal sensing optical fiber is arranged in the friction sleeve, the upper end of the signal sensing optical fiber is connected with the probe rod, the lower end of the signal sensing optical fiber is connected with an inclinometer, a frictional resistance sensing optical fiber is arranged on the outer side of the signal sensing optical fiber in the friction sleeve, a plurality of water sealing rings are arranged between the frictional resistance sensing optical fiber and the inner wall of the friction sleeve, a pore water pressure sensing optical fiber is arranged between the frictional resistance sensing optical fiber close to the probe and the inner wall of the.
The working state of the Brillouin optical time domain reflectometer (BOTRD) can be controlled manually or by a computer, so that the automatic acquisition and processing of data can be realized. The resulting data file may be stored on a hard disk built into the BOTDR.
The computer can analyze and calculate the data file transmitted by the BOTRD through the data processing module.
The CPTU device applying the optical fiber technology is a complete system and has no defect.
Compared with the prior art, the invention has the beneficial effects that: the CPTU probe of the invention changes various sensors including a pressure sensor and a friction sleeve sensor into sensing optical fibers for measurement on the basis of the original CPTU probe; the connecting line of the transmission cable and the sensor is changed into a sensing optical fiber for transmission. The optical fibers are integrated, namely the optical fibers inside the CPTU and the optical fibers outside the CPTU are integrated, the sensing optical fibers for measurement and the sensing optical fibers for transmission are made of the same optical fiber material, and the diameters of the sensing optical fibers and the sensing optical fibers for transmission are 900 mu m. The response speed in the CPTU test process is increased and the sensitivity is improved through the transmission action of the optical fiber; the optical fiber has the advantages of strong reliability, long service life, strong capability of resisting various electromagnetic and radio frequency interferences and good corrosion resistance, and can work and operate in the severe environment of the ocean; the optical fiber can keep good transmission signals in the long-distance transmission process, can be remotely monitored in real time on line, can be remotely operated to check results, saves labor cost and improves management efficiency. The CPTU device applying the optical fiber technology can be applied to CPTU tests in other fields and conditions, and has wide application value.
Drawings
FIG. 1 is a schematic diagram of the system of the present invention.
FIG. 2 is a schematic diagram of a CPTU probe according to the present invention;
in the figure, 1-probe, 2-optical fiber, 3-Brillouin optical time domain reflectometer, 4-network cable, 5-computer, 6-sealing sleeve, 7-GPIB communication interface and network interface, 8-friction sleeve, 9-probe rod, 10-pressure sensing optical fiber, 11-pore water pressure sensing optical fiber, 12-friction force sensing optical fiber, 13-pressure rod connector, 14-soil body sealing ring, 15-signal sensing optical fiber, 16-water sealing ring, 17-inclinometer, 18-friction sleeve and 19-filter.
Detailed Description
The invention will be further explained with reference to the drawings.
As shown in fig. 1 to 2, a CPTU device suitable for applying optical fiber technology in shallow sea geology comprises a CPTU probe, a probe rod 9, a sensing optical fiber 2, a sealing sleeve 6, a brillouin optical time domain reflectometer 3, a network cable 4 and a computer 5. The sealing sleeve 6 is of a hollow tubular structure; the sealing sleeve 6 is connected to one end of the CPTU probe in a sealing mode, and the other end of the CPTU probe is connected to one end of the Brillouin optical time domain reflectometer 3; the optical fiber 2 is arranged in a sealed sleeve 6, and the Brillouin optical time domain reflectometer 3 is connected with a computer 5 through a network cable 4.
The CPTU probe is improved on the basis of a standard piezocone penetration test (CPTU) probe, the positions of a pressure sensor, a cone sensor and a friction sleeve sensor are changed into a pressure sensing optical fiber 10, a pore water pressure sensing optical fiber 11 and a frictional resistance sensing optical fiber 12 with higher precision, and the CPTU probe is stuck at the position after a certain prestress is applied; the signal transmission cable is replaced by the signal sensing optical fiber 15 with the higher transmission speed, the rest parts are not changed, and the diameter of the sensing optical fiber is 900 mu m.
The CPTU probe is formed by sequentially connecting a probe rod 9, a friction sleeve 8 and a probe 1, wherein the probe rod 9 is connected with the friction sleeve 8 through a pressure rod connector, a soil body sealing ring 14 is arranged between the friction sleeve 8 and the probe 1, the soil body sealing ring 14 is arranged between the friction sleeve 8 and the probe 1, a signal sensing optical fiber 15 is arranged in the friction sleeve 8, the upper end of the signal sensing optical fiber 15 is connected with the probe rod 9, the lower end of the signal sensing optical fiber 15 is connected with an inclinometer 17, a frictional resistance sensing optical fiber 12 is arranged on the outer side of the signal sensing optical fiber 1 in the friction sleeve 8, a plurality of water sealing rings 16 are arranged between the frictional resistance sensing optical fiber 12 and the inner wall of the friction sleeve 8, a pore water pressure sensing optical fiber 11 is arranged between the frictional resistance sensing optical fiber 12 close to the probe 1 and the inner wall of the friction sleeve 8.
After the sensing optical fibers and the optical fiber transmission lines of each part are laid, the optical fibers are accessed into a data acquisition instrument to test the connectivity of the lines, and data is acquired in a trial mode to determine the validity of the data.
Sufficient length should be reserved to the optic fibre transmission line outside the CPTU probe, should reserve watertight joint in CPTU probe outlet position simultaneously, conveniently installs sealed sleeve pipe outside optical fiber sensor, guarantees that inside optic fibre transmission line does not receive external environment and destroys.
Principle of brillouin optical time domain reflectometry: based on the principle of brillouin backscattering, when the BOTDR injects short pulse light into the optical fiber, the strain at a certain position of the optical fiber changes, and the frequency of the scattered brillouin light also changes correspondingly. The drift of the Brillouin frequency and the strain borne by the optical fiber are in a good linear relation, and further the conditions such as stress can be indirectly known.
The GPIB communication interface and the network interface 7 provided by the Brillouin optical time domain reflectometer 3 realize the communication with the computer 5, and the working state of the Brillouin optical time domain reflectometer can be controlled manually or by a computer, so that the automatic acquisition and processing of data can be realized. The obtained data files can be stored on a hard disk built in the BOTDR, or can be transmitted to a computer through a network by a communication interface of the BOTDR, and then the data files are analyzed and calculated by a data processing module.
The Brillouin optical time domain reflectometer was manufactured by Rui Ke photoelectricity corporation, model number RP 4000.
The principle of the CPTU device applying the optical fiber technology in shallow sea geology is that a bottom cone-tip type probe 1 measures the resistance of seabed geology to a cone tip in the uniform penetration process, a static sounding main body measures the side friction resistance and the pore water pressure of the seabed geology to a cylinder in the uniform penetration process, sensing optical fibers are respectively arranged on the surface of a test surface at the positions where a pressure sensor, a cone sensor and a friction sleeve sensor are originally placed, when the external environment changes, the BOTDR injects short pulse light into the optical fibers, the strain of the optical fibers at a certain position of the sensor changes, and then the parameters such as soil resistance, the side friction resistance, the pore water pressure and the like can be obtained, and the sounding process is completed.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
Claims (6)
1. A CPTU device applying an optical fiber technology in shallow sea geology is characterized by comprising a CPTU probe, an optical fiber, a probe rod, a sealing sleeve, a Brillouin optical time domain reflectometer, a network cable and a computer; the sealing sleeve is of a hollow tubular structure; the sealing sleeve is connected to one end of the CPTU in a sealing mode, and the other end of the sealing sleeve is connected to one end of the Brillouin optical time domain reflectometer; the optical fiber is arranged in the sealed sleeve, and the Brillouin optical time domain reflectometer is connected with a computer through a network cable.
2. The CPTU apparatus employing fiber optic technology in shallow sea geology of claim 1, wherein said Brillouin optical time domain reflectometer utilizes a GPIB communication interface and a network interface to communicate with a computer via a network cable.
3. The CPTU apparatus of claim 1, wherein the CPTU probe comprises a probe rod, a friction sleeve and a probe head connected in sequence, the probe rod is connected with the friction sleeve through a pressure rod connector, a soil body sealing ring is arranged between the friction sleeve and the probe head, the friction sleeve and the probe head are screwed together through screw threads, the soil body sealing ring is arranged between the friction sleeve and the probe head, the friction sleeve is internally provided with a signal sensing optical fiber, the upper end of the signal sensing optical fiber is connected with the probe rod, the lower end of the signal sensing optical fiber is connected with an inclinometer, the outer side of the signal sensing optical fiber in the friction sleeve is provided with a friction force sensing optical fiber, a pore water pressure sensing optical fiber is arranged between the friction force sensing optical fiber close to the probe head and the inner wall of the friction.
4. A CPTU apparatus using fiber optic technology in shallow sea geology as claimed in claim 1, wherein said probe is further equipped with a filter.
5. The CPTU apparatus of claim 1, wherein a plurality of watertight seals are provided between the frictional force sensing optical fiber and the inner wall of the friction sleeve.
6. The CPTU apparatus using fiber optic technology in shallow sea geology according to claim 1, wherein said Brillouin optical time domain reflectometer is controlled by computer or manually for automatic data acquisition and processing, and the obtained data file is stored in a built-in hard disk.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202010284121.9A CN111395297A (en) | 2020-04-13 | 2020-04-13 | CPTU device applying optical fiber technology in shallow sea geology |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010284121.9A CN111395297A (en) | 2020-04-13 | 2020-04-13 | CPTU device applying optical fiber technology in shallow sea geology |
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| CN202010284121.9A Pending CN111395297A (en) | 2020-04-13 | 2020-04-13 | CPTU device applying optical fiber technology in shallow sea geology |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114061664A (en) * | 2021-11-19 | 2022-02-18 | 中国海洋大学 | Submarine pore water multi-parameter in-situ observation probe rod and method based on fiber bragg grating |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1598479A (en) * | 2004-09-15 | 2005-03-23 | 南京大学 | Distribution type optical fibre measuring method and system for deep deformation of soil |
| US20100257920A1 (en) * | 2009-04-10 | 2010-10-14 | Jong-Sub Lee | Cone penetrometers for measuring impedance of ground |
| CN107966169A (en) * | 2016-10-20 | 2018-04-27 | 辉固科技有限公司 | For determining the probe of soil property |
-
2020
- 2020-04-13 CN CN202010284121.9A patent/CN111395297A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1598479A (en) * | 2004-09-15 | 2005-03-23 | 南京大学 | Distribution type optical fibre measuring method and system for deep deformation of soil |
| US20100257920A1 (en) * | 2009-04-10 | 2010-10-14 | Jong-Sub Lee | Cone penetrometers for measuring impedance of ground |
| CN107966169A (en) * | 2016-10-20 | 2018-04-27 | 辉固科技有限公司 | For determining the probe of soil property |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114061664A (en) * | 2021-11-19 | 2022-02-18 | 中国海洋大学 | Submarine pore water multi-parameter in-situ observation probe rod and method based on fiber bragg grating |
| CN114061664B (en) * | 2021-11-19 | 2022-07-05 | 中国海洋大学 | Submarine pore water multi-parameter in-situ observation probe rod and method based on fiber bragg grating |
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Application publication date: 20200710 |