CN114215035A - Static sounding probe combined with TDR technology, detection system and measurement method - Google Patents
Static sounding probe combined with TDR technology, detection system and measurement method Download PDFInfo
- Publication number
- CN114215035A CN114215035A CN202111588304.0A CN202111588304A CN114215035A CN 114215035 A CN114215035 A CN 114215035A CN 202111588304 A CN202111588304 A CN 202111588304A CN 114215035 A CN114215035 A CN 114215035A
- Authority
- CN
- China
- Prior art keywords
- probe
- tdr
- detection mechanism
- cone
- soil body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000523 sample Substances 0.000 title claims abstract description 159
- 238000001514 detection method Methods 0.000 title claims abstract description 57
- 230000003068 static effect Effects 0.000 title claims abstract description 47
- 238000005516 engineering process Methods 0.000 title claims abstract description 14
- 238000000691 measurement method Methods 0.000 title abstract description 7
- 239000002689 soil Substances 0.000 claims abstract description 103
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 78
- 230000007246 mechanism Effects 0.000 claims abstract description 46
- 239000011148 porous material Substances 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 26
- 238000005259 measurement Methods 0.000 claims abstract description 19
- 238000012360 testing method Methods 0.000 claims description 47
- 238000001914 filtration Methods 0.000 claims description 15
- 239000005416 organic matter Substances 0.000 claims description 15
- 230000008569 process Effects 0.000 claims description 14
- 230000035515 penetration Effects 0.000 claims description 13
- 238000011065 in-situ storage Methods 0.000 claims description 11
- 239000010410 layer Substances 0.000 claims description 7
- 239000002344 surface layer Substances 0.000 claims description 3
- 230000007704 transition Effects 0.000 claims description 3
- 230000008901 benefit Effects 0.000 abstract description 2
- 230000005540 biological transmission Effects 0.000 description 9
- 230000008859 change Effects 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000005070 sampling Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000007596 consolidation process Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000002310 reflectometry Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000004016 soil organic matter Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000000476 body water Anatomy 0.000 description 1
- 238000001739 density measurement Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Images
Classifications
-
- 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
-
- 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
- E02D1/027—Investigation of foundation soil in situ before construction work by investigating properties relating to fluids in the soil, e.g. pore-water pressure, permeability
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/041—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/048—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance for determining moisture content of the material
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/22—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
- G01N27/221—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance by investigating the dielectric properties
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
- G01N9/24—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity by observing the transmission of wave or particle radiation through the material
Abstract
The invention relates to a static sounding probe combined with TDR technology, a detection system and a measurement method, wherein the probe comprises a conical head, a probe rod, a probe control unit, a TDR probe, a first detection mechanism for detecting the resistance of the conical tip, a second detection mechanism for detecting the side friction resistance and a third detection mechanism for detecting the pore water pressure, the conical head comprises a conical section and a cylindrical section, the TDR probe is provided with a plurality of TDR probes, the outer side wall of the conical head is provided with clamping grooves with the same number as the TDR probes, the clamping grooves are arranged around the surface of the conical head at equal angles, the TDR probes are respectively embedded in the clamping grooves, the TDR probe is parallel to the axial direction of the conical head, an insulating layer is arranged on the contact surface of the TDR probe and the conical head, the end part of the TDR probe is conical and extends to the conical section of the conical head, and the TDR probe and each detection mechanism are connected with the probe control unit. Compared with the prior art, the method has the advantages of improving the measurement accuracy, being capable of continuously measuring a plurality of parameters of the soil body and the like.
Description
Technical Field
The invention relates to the field of soil body in-situ test, in particular to a static sounding probe combined with a TDR (time domain reflectometry) technology, a detection system and a measurement method.
Background
The soil body conductivity, the dielectric constant and the temperature are used as important parameters for evaluating soil, the soil body conductivity is widely applied to the field of environmental rock and soil, the soil body conductivity can be used for evaluating the content of organic matters in a soil body, the relationship between the soil body conductivity and the soil body pore water conductivity can be established, the pollution condition of the soil body can be monitored, and important parameters such as the water content, the dry density and the like of the soil body can be calculated by measuring the soil body dielectric constant. Temperature is one of the main factors influencing the consolidation creep characteristics of the geotechnical materials, the influence on the deformation of geotechnical engineering cannot be ignored, and the engineering properties of the cohesive soil can be changed under repeated temperature changes, so that a series of engineering problems such as deformation, settlement and the like can be caused.
The measurement of the conductivity of the soil body is generally carried out through a sampling test or in-situ test in a drill hole, the measurement of the conductivity of the soil body in agriculture is only the measurement of the conductivity of the surface of the soil body, the sampling test is that original soil is damaged in the sampling process, the measured conductivity and temperature of the soil body are not in accordance with the reality, the in-situ test in the drill hole is that a Time Domain Reflectometry (TDR) probe is inserted into the soil body to be measured on the basis of the drill hole for measurement, but in the engineering practice, the soil body in the field needs to be measured at multiple points, and the in-situ test of the drill hole obviously does not meet the economic benefit.
The measurement of the conductivity, the dielectric constant and the temperature of the soil body can be used for evaluating the content of organic matters, the water content, the temperature, the dry density, the pollution degree and the like of the soil body, which are parameters frequently required to be measured in a model test, a common indoor model test mostly adopts a scale-down test, the measurement of the parameters is mostly carried out by embedding sensors in advance, the arrangement of the sensors is limited due to the limited model size, the common indoor test is only carried out by arranging the sensors at special positions, the whole model is evaluated according to the measurement result of the special positions, the error of the test is increased frequently, the test requirement cannot be met, and the simulation effect of the test is influenced by the embedding of too many sensors, so that the multifunctional static sounding equipment is required when the model test is carried out, and not only the parallel measurement of a plurality of indexes can be carried out, the relevance among all indexes is improved, continuous multipoint or different-depth measurement on the model can be realized, and the requirement of an indoor model experiment is met.
The piezocone penetration test is a common in-situ test technology, and cone tip resistance, side friction resistance and super-pore water pressure in the penetration process can be measured by in-situ test in an engineering field. The basic principle is that a static sounding probe with a sensor inside is pressed into a soil body at a constant speed, the resistance of the probe is different in the pressing-in process due to different soil layers, the sensor records the difference of the resistance of the probe, and then the soil layer section, the consolidation coefficient, the soil layer bearing capacity and the pile end bearing capacity layer are selected through the qualitative relation and the statistical correlation relation between the penetration resistance and the engineering geological characteristics of the soil. The probe can generate the excess pore water pressure in the pressing process, and the produced excess pore water pressure is measured by the pore water pressure sensor. Compared with traditional drilling, sampling and indoor tests, the piezocone penetration test has the characteristics of accuracy, economy and quickness. But it cannot measure the conductivity, dielectric constant and temperature etc. deep in the soil body in situ.
The technical personnel in the field need to obtain a probe which can measure the conductivity, dielectric constant and temperature in the soil body in situ.
Disclosure of Invention
The invention aims to provide a static sounding probe combined with a TDR technology, a detection system and a measurement method.
The purpose of the invention can be realized by the following technical scheme:
a static sounding probe combined with TDR technology comprises a cone head, a probe rod, a probe control unit, a TDR probe, a first detection mechanism for detecting cone tip resistance, a second detection mechanism for detecting side friction resistance and a third detection mechanism for detecting pore water pressure,
the cone head comprises a cone section and a cylindrical section, the TDR probes are provided with a plurality of TDR probes, the outer side wall of the cone head is provided with clamping grooves with the same number as the TDR probes, the clamping grooves are arranged around the surface of the cone head at equal angles, the TDR probes are respectively embedded in the clamping grooves, the directions of the TDR probes are parallel to the axial direction of the cone head, an insulating layer is arranged on the contact surface of the TDR probes and the cone head, the end parts of the TDR probes are tapered, extend to the cone section of the cone head and are in smooth transition with the conical surface of the cone section,
the TDR probe, the first detection mechanism, the second detection mechanism and the third detection mechanism are all connected with the probe control unit.
The number of the TDR probes is three.
And a temperature sensor is arranged in the TDR probe.
The root of the TDR probe extends to the end of the cylindrical section.
The first detection mechanism comprises a conical head deformation column and a piezoresistive conical tip resistance sensor, the conical head deformation column and a conical tip are coaxially arranged and are close to a tip part of the conical head, and the conical tip resistance sensor is arranged at the rear end of the conical head deformation column.
The second detection mechanism comprises a friction cylinder, a side wall deformation column and a piezoresistive side wall friction resistance sensor, the friction cylinder is arranged on the outer side of the probe rod, the side wall deformation column is arranged on the surface layer of the probe rod, and the side wall friction resistance sensor is arranged on the inner side of the side wall deformation column.
The third detection mechanism comprises a filter screen, a water filtering channel, a water cavity and a pressure resistance type pore water pressure sensor, a water permeable hole is formed in the conical head, is connected with the water filtering channel and communicated with the outside, the water pressure cavity is arranged at the front end of the base and is located on the rear side of the water filtering channel, and the pore water pressure sensor is arranged on the inner side of the water pressure cavity.
The soil body in-situ detection system comprising the probe comprises the probe, a multifunctional static sounding terminal and a TDR test system terminal, wherein a probe control unit of the probe is respectively connected with the multifunctional static sounding terminal and the TDR test system terminal through leads.
A measurement method of a system as above, comprising:
step S1: completing calibration of the conductivity, the dry density and the organic matter content of the soil body based on a physical model box with known conductivity, dry density and organic matter content of the soil body;
step S2: the probe is penetrated into a soil body to be tested, and simultaneously, a TDR test system terminal sends an electromagnetic wave signal to a TDR probe;
step S3: collecting the reflected signal of the electromagnetic wave signal in the penetration process to obtain the conductivity, dielectric constant, water content, organic matter content and dry density of the soil body,
and receiving the cone tip resistance, the side friction resistance and the pore water pressure which are respectively acquired by the first detection mechanism, the second detection mechanism and the third detection mechanism in the penetration process.
And the water content of the soil body is obtained by calculating the dielectric constant of the soil body. Specifically, the water content and the dry density of the soil body are calculated by the dielectric constant, and the organic matter content of the soil body is calculated by the conductivity.
Compared with the prior art, the invention has the following beneficial effects: through special design's TDR probe structure, combine TDR probe and piezocone sounding probe, thereby can be quick, conveniently measure the end frictional resistance of certain degree of depth ground body, side direction frictional resistance, pore water pressure, the conductivity, the dielectric constant, the temperature isoparametric, and the multiple nature of depth direction ground body is followed in reflection that can be more abundant, the combination probe can obtain the soil body along each parameter of depth direction in succession at the injection in-process, make the correlation stronger between each parameter of surveying, the TDR probe has also been avoided simultaneously and has been crushed at the injection in-process, lead to TDR probe and the problem that the bad conductivity of ground body leads to can not accurately reflect around ground body contact.
Drawings
FIG. 1 is a schematic view of the structure of a probe according to the present invention;
FIG. 2 is a schematic view of the probe tip end;
FIG. 3 is a schematic view of a detection system of the present invention;
wherein: 1. the cone head, 2, a filter screen, 3, a water filtering channel, 4, a cone head deformation column, 5, a cone tip resistance sensor, 6, a pore water pressure sensor, 7, a water pressure cavity, 8, a friction cylinder, 9, a side wall deformation column, 10, a side wall friction resistance sensor, 11, a probe control unit, 12, a TDR probe, 13, a cable channel, 14, a connecting rod, 15, a TDR test system terminal, 16, a power supply, 17, a signal collector, 18, a signal generator, 19, a coaxial router, 20, a multifunctional static sounding terminal, 21, a sealing ring, 22, a base, 23, a coaxial transmission line, 24, a multifunctional static sounding display.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
A static sounding probe combined with TDR technology comprises a conical head 1, a probe rod and a probe control unit 11, and TDR probe 12, the first detection mechanism for detecting the cone tip resistance, the second detection mechanism for detecting the side friction resistance and the third detection mechanism for detecting the pore water pressure, wherein the cone head 1 comprises a cone section and a cylinder section, the TDR probe 12 is provided with a plurality of the TDR probes, the outer side wall of the cone head 1 is provided with clamping grooves with the same number as the TDR probes 12, the clamping grooves are arranged around the surface of the cone head 1 at equal angles, the TDR probes 12 are respectively embedded in the clamping grooves, the direction of the TDR probe 12 is parallel to the axial direction of the conical head 1, an insulating layer is arranged on the contact surface of the TDR probe 12 and the conical head 1, the end part of the TDR probe 12 is conical and extends to the conical section of the conical head 1, and is in smooth transition with the conical surface of the conical section, and the TDR probe 12, the first detection mechanism, the second detection mechanism and the third detection mechanism are all connected with the probe control unit 11.
Through special design's TDR probe 12 structure, combine TDR probe and piezocone penetration test probe, thereby can be quick, conveniently measure the end frictional resistance of certain degree of depth ground body, side direction frictional resistance, pore water pressure, the conductivity, the dielectric constant, the temperature isoparametric, and the multiple nature of depth direction ground body is followed in reflection that can be more abundant, the combination probe can obtain the soil body along each parameter of depth direction in succession at the injection in-process, make the correlation stronger between each parameter of surveying, also avoided TDR probe 12 to be crushed at the injection in-process simultaneously, lead to TDR probe 12 and the problem of the conductivity of ground body that can not the accurate reflection ground body that leads to the contact failure of ground body on every side.
In this embodiment, the number of the TDR probes 12 is three, and the TDR probes are arranged at intervals of 120 degrees, so that excessive influence on the structure of the original piezocone sounding probe can be avoided, and the accuracy of the reflected signal is maintained.
In this embodiment, the TDR probe 12 is provided with a temperature sensor therein, which can collect temperature information, and reduces measurement errors caused by interference of a heat source inside the probe at the outermost side.
In this embodiment, the root of the TDR probe 12 extends to the end of the cylindrical section, increasing the transmission path of the electromagnetic wave and improving the accuracy of the measurement.
In this embodiment, the first detection mechanism includes a cone head 1 deformation column and a piezoresistive cone tip resistance sensor 5, the cone head 1 deformation column and the cone tip are coaxially arranged and are close to a tip portion of the cone head 1, and the cone tip resistance sensor 5 is installed at a rear end of the cone head 1 deformation column.
In this embodiment, the second detection mechanism includes a friction cylinder 8, a sidewall deformation column 9, and a piezoresistive sidewall frictional resistance sensor 10, where the friction cylinder 8 is disposed on the outer side of the probe rod, the sidewall deformation column 9 is disposed on the surface layer of the probe rod, and the sidewall frictional resistance sensor 10 is mounted on the inner side of the sidewall deformation column 9.
In this embodiment, the third detection mechanism includes a filter screen 2, a water filtering channel 3, a water chamber and a pressure-resistance type pore water pressure sensor 6, the water permeable holes are formed in the conical head 1, are connected with the water filtering channel 3, and are communicated with the outside, the water pressure chamber 7 is arranged at the front end of the base 22, the water pressure chamber 7 is located at the rear side of the water filtering channel 3, and the pore water pressure sensor 6 is arranged at the inner side of the water pressure chamber 7. Specifically, the water filtering channel 3 is arranged in the middle of the conical head 1 and the base 22, the filter screen 2 is arranged at the contact part of the water filtering channel 3 and the soil body, the rear end of the water filtering channel 3 is connected with the water pressure chamber 7, and the front end of the water filtering channel is communicated with the outside.
The probe rod mainly comprises a base 22, a connecting rod 14 and a cable channel 13, wherein the base 22 and the connecting rod 14 are coaxially arranged on the rear side of the conical tip probe, the cable channel 13 is arranged inside the base 22 and is coaxial with the conical tip probe, the cable channel 13 is coaxial with the external probe rod cable channel 13, and a sealing ring 21 is arranged at the rear end of the cable channel 13.
Another aspect of the present application provides a soil in-situ detection system including the probe as described above, including the probe, the multifunctional static sounding terminal 20 and the TDR testing system terminal 15, where the probe control unit 11 of the probe is connected to the multifunctional static sounding terminal 20 and the TDR testing system terminal 15 through wires, respectively.
The TDR probe 12 is used as a fourth detection mechanism and is electrically connected with the other three detection mechanisms, the first detection mechanism, the second detection mechanism and the third detection mechanism are respectively and simultaneously electrically connected with the multifunctional static sounding terminal, and the fourth detection mechanism is electrically connected with the TDR test system terminal 15. The probe can accurately and rapidly measure the cone tip resistance, the side friction resistance and the pore water pressure, can measure the conductivity, the dielectric constant and the temperature of a soil body, is convenient for detection personnel to obtain the water content, the dry density, the temperature and the organic matter content of undisturbed soil, and monitors the pollution condition of the soil body.
In this embodiment, the outside of the TDR probe 12 directly contacts with the soil, the temperature sensor is installed in the test probe, the test probe is electrically connected with the test probe, and the test probe is electrically connected with the TDR test system terminal 15 through the coaxial transmission line 23 of the cable channel 13.
The TDR test system terminal 15 is composed of a power supply 16, a signal generator 18, a signal collector 17 and a coaxial router 19, and is electrically connected with the TDR detection probe through a coaxial transmission line 23 and is also electrically connected with the multifunctional static sounding probe terminal.
This application measurable quantity soil body conductivity, dielectric constant and temperature, it settles on the probe to become one hundred twenty degrees each other with TDR probe 12, the probe is direct and soil body contact, and temperature sensor is equipped with on the probe, when sounding to different degree of depth soil bodies, ground TDR signal generator 18 launches electromagnetic wave signal, the electromagnetic wave propagates to probe department TDR test probe through coaxial transmission line 23, electromagnetic wave signal propagates along the probe, it is discontinuous at probe initial position and termination position wave impedance, electromagnetic wave signal will produce the reflection here, ground TDR signal collector 17 records the voltage along with the change relation of time that the back wave produced, and save data, can calculate and obtain soil body conductivity through carrying out the analysis to the relation curve of back wave voltage and time.
The measured conductivity of the soil body can be used for evaluating the content of organic matters in the soil body according to the conversion relation, establishing the relation between the conductivity of the soil body and the conductivity of pore water in the soil body, monitoring the pollution condition of the soil body, and evaluating the change rule of the conductivity of the reinforced soil along with the chemical reaction in the soil.
Electromagnetic waves are transmitted to the probe control unit 11 through a coaxial transmission wire and reflected on the impedance discontinuous surface at the beginning and the end of the probe, the ground TDR signal collector 17 records the change relation of voltage generated by reflected waves along with time, data is stored, and the dielectric constant of the soil body can be calculated by analyzing the relation curve of the voltage of the reflected waves and the time.
The method mainly comprises the steps of analyzing the dielectric constant of the soil body, wherein the dielectric constant of water is 81, the dielectric constant of soil body particles is 3-5, and the dielectric constant of water is far larger than that of the soil body particles, so that the dielectric constant of the soil body is mainly determined by the content of water in the soil particles, and the water content is determined by an empirical formula between the common soil body dielectric constant and the water content.
A certain empirical relationship exists among the dielectric constant, the mass water content and the dry density of the soil body, and the dry density of the soil body can be obtained through indoor calibration and the empirical relationship.
After the measured soil body conductivity, dielectric constant and temperature are processed by the TDR terminal, data are transmitted to the multifunctional static sounding terminal 20, meanwhile, the multifunctional static sounding terminal 20 records and stores cone tip resistance, side friction resistance and ultra-pore water pressure, the multifunctional static sounding terminal 20 can display the relation of parameters such as the cone tip resistance, the side friction resistance, the ultra-pore water pressure, the soil body conductivity, the dielectric constant and the temperature along with the depth in real time in the sounding process, and when a certain parameter is abnormal or meets the engineering requirement, static sounding can be timely adjusted or terminated.
The soil organic matter content is closely related to the soil conductivity and has an empirical relationship, and the soil organic matter content can be obtained through early calibration and the empirical relationship.
Based on this, the present application provides a measurement method of the system as described above, including:
step S1: completing calibration of the conductivity, the dry density and the organic matter content of the soil body based on a physical model box with known conductivity, dry density and organic matter content of the soil body;
step S2: the probe is penetrated into a soil body to be tested, and simultaneously, a TDR test system terminal sends an electromagnetic wave signal to a TDR probe;
step S3: collecting the reflected signal of the electromagnetic wave signal in the penetration process to obtain the conductivity, dielectric constant, water content, organic matter content and dry density of the soil body,
and receiving the cone tip resistance, the side friction resistance and the pore water pressure which are respectively acquired by the first detection mechanism, the second detection mechanism and the third detection mechanism in the penetration process.
The specific process is as follows:
1. before the experiment, the conductivity measurement needs to be calibrated, firstly the conductivity of the soil body of the model box is measured by an indoor test method, then the probe is put into the model box for sounding, the conductivity of the soil body at different depths and different positions is measured, and the measurement of the conductivity is calibrated according to the known conductivity of the soil body model and the change relation of the voltage generated by the reflected wave along with the time.
2. The dry density of the soil body needs to be calibrated before the experiment, similar to the previous calibration method, the dry density and the mass water content of the model soil body are measured through an indoor model box experiment, then a probe is placed into the model box for sounding to obtain the dielectric constant of the soil body, and the dry density measurement is calibrated through multi-point measurement of the model soil body.
3. Before the test, the measurement of the content of the organic matter in the soil body needs to be calibrated, similar to the previous calibration method, the content of the organic matter in the soil body of the model is measured through an indoor model box test, then a probe is put in the model for sounding measurement to obtain the conductivity of the soil body, and the content of the organic matter in the soil body is calibrated through the multi-point measurement of the model soil body.
4. When the probe penetrates downwards, the cone tip can be subjected to soil resistance and transmits the resistance to the cone head deformation column 4, the cone head deformation column deforms, the piezoresistive cone tip resistance sensor converts a deformation signal into an electric signal and transmits the electric signal to the multifunctional static sounding terminal 20, and the multifunctional static sounding display 24 displays the resistance result of the cone tip through processing the electric signal by the terminal. The cone tip frictional resistance can be accurately and quickly read from the ground multifunctional static sounding terminal display.
5. When the probe penetrates downwards, the surrounding soil body and the friction cylinder 8 generate friction force, the friction force is transmitted to the side wall deformation column 9 to cause the side wall deformation column 9 to deform, the piezoresistive side wall friction resistance sensor 10 converts the deformation signal into an electric signal and transmits the electric signal to the multifunctional static sounding terminal 20, and the multifunctional static sounding display 24 displays the side wall friction resistance result through processing the electric signal by the terminal. The side wall friction force can be accurately and quickly read from the ground multifunctional static sounding terminal display 24.
6. When the probe penetrates downwards, the probe extrudes surrounding soil, pore water penetrates through the filter screen 2 and reaches the water pressure cavity 7 along the water filtering channel 3, the water pressure in the water pressure cavity 7 changes, the pore water pressure sensor 6 converts the change into an electric signal and transmits the electric signal to the multifunctional static sounding terminal 20, and the multifunctional static sounding display 24 displays the size of the super-pore water pressure through processing the electric signal by the terminal system. The super-pore water pressure can be accurately and quickly read from the ground multifunctional static sounding terminal display 24.
7. When the probe penetrates downwards, the TDR probe 12 installed on the probe cone tip is in contact with the surrounding soil body, the ground signal generator 18 emits electromagnetic wave signals, the electromagnetic wave signals are transmitted to the TDR detection probe 11 through the coaxial transmission line 23 and then transmitted to the TDR probe 12, the electromagnetic wave signals are reflected at the initial position and the final position of the probe 12, the reflected signals are transmitted to the signal collector 17 through the coaxial transmission line 23, the TDR test system terminal 15 obtains a TDR test waveform curve through processing of the reflected electromagnetic wave signals and transmits the curve to the static sounding terminal 20, and the multifunctional static sounding terminal display 24 displays the TDR test waveform curve.
8. The multifunctional static sounding terminal 20 has a calculation function, and inputs parameters obtained by early calibration into a module to be calculated, and the static sounding terminal system automatically extracts a characteristic value of a TDR test waveform curve, and obtains the soil body conductivity, the dielectric constant, the soil body water content, the soil body organic matter content and the dry density equivalent according to the early calibration result and a calculation formula.
9. When the probe penetrates downwards, the temperature sensor in the TDR probe 12 detects the temperature of the surrounding soil body, converts a temperature signal into an electric signal, transmits the electric signal to the TDR test system terminal 15, the TDR test system terminal 15 processes the electric signal, transmits the processed electric signal to the multifunctional static sounding terminal 20, and the multifunctional static sounding terminal display 24 displays the temperature of the soil body. The soil temperature can be quickly and accurately read from the ground multifunctional static sounding terminal display 24.
10. This multi-functional type static sounding terminal 20 has the real-time storage function, records and stores the signal of telecommunication of each sensor and TDR test system terminal 15 transmission at the sounding in-process to it is convenient to derive, is favorable to technical staff and scientific research personnel later stage to handle data.
Claims (10)
1. A static sounding probe combined with TDR technology is characterized by comprising a cone head, a probe rod, a probe control unit, a TDR probe, a first detection mechanism for detecting cone tip resistance, a second detection mechanism for detecting side friction resistance and a third detection mechanism for detecting pore water pressure,
the cone head comprises a cone section and a cylindrical section, the TDR probes are provided with a plurality of TDR probes, the outer side wall of the cone head is provided with clamping grooves with the same number as the TDR probes, the clamping grooves are arranged around the surface of the cone head at equal angles, the TDR probes are respectively embedded in the clamping grooves, the directions of the TDR probes are parallel to the axial direction of the cone head, an insulating layer is arranged on the contact surface of the TDR probes and the cone head, the end parts of the TDR probes are tapered, extend to the cone section of the cone head and are in smooth transition with the conical surface of the cone section,
the TDR probe, the first detection mechanism, the second detection mechanism and the third detection mechanism are all connected with the probe control unit.
2. A static cone penetration probe incorporating TDR techniques according to claim 1 wherein the number of TDR probes is three.
3. A static sounding probe incorporating TDR technology according to claim 1, wherein a temperature sensor is provided in the TDR probe.
4. A static sounding probe incorporating TDR technology according to claim 1, wherein the TDR probe has a root portion extending to the end of the cylindrical section.
5. A static cone penetration probe combined with TDR technology according to claim 1, wherein said first detection mechanism comprises a cone head deformation column and a piezoresistive cone tip resistance sensor, said cone head deformation column is arranged coaxially with the cone tip and near the tip part of the cone head, and the cone tip resistance sensor is mounted at the rear end of the cone head deformation column.
6. The static sounding probe combined with the TDR technology of claim 1, wherein the second detection mechanism comprises a friction cylinder, a sidewall deformation column, and a piezoresistive sidewall frictional resistance sensor, the friction cylinder is disposed on the outer side of the probe rod, the sidewall deformation column is disposed on the surface layer of the probe rod, and the sidewall frictional resistance sensor is mounted on the inner side of the sidewall deformation column.
7. The static sounding probe combining the TDR technology according to claim 1, wherein the third detecting mechanism comprises a filter screen, a water filtering channel, a water cavity and a pressure-resistance pore water pressure sensor, the water permeable hole is formed on the cone head, is connected with the water filtering channel, and is communicated with the outside, the water pressure cavity is formed at the front end of the base and is located at the rear side of the water filtering channel, and the pore water pressure sensor is arranged at the inner side of the water pressure cavity.
8. A soil in-situ detection system comprising the probe of any one of claims 1 to 7, wherein the system comprises the probe, a multifunctional static sounding terminal and a TDR test system terminal, and a probe control unit of the probe is respectively connected with the multifunctional static sounding terminal and the TDR test system terminal through leads.
9. A method of measurement of the system of claim 8, comprising:
step S1: completing calibration of the conductivity, the dry density and the organic matter content of the soil body based on a physical model box with known conductivity, dry density and organic matter content of the soil body;
step S2: the probe is penetrated into a soil body to be tested, and simultaneously, a TDR test system terminal sends an electromagnetic wave signal to a TDR probe;
step S3: collecting the reflected signal of the electromagnetic wave signal in the penetration process to obtain the conductivity, dielectric constant, water content, organic matter content and dry density of the soil body,
and receiving the cone tip resistance, the side friction resistance and the pore water pressure which are respectively acquired by the first detection mechanism, the second detection mechanism and the third detection mechanism in the penetration process.
10. The method of claim 9, wherein the water content of the soil mass is calculated from a dielectric constant of the soil mass.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111588304.0A CN114215035A (en) | 2021-12-23 | 2021-12-23 | Static sounding probe combined with TDR technology, detection system and measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111588304.0A CN114215035A (en) | 2021-12-23 | 2021-12-23 | Static sounding probe combined with TDR technology, detection system and measurement method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114215035A true CN114215035A (en) | 2022-03-22 |
Family
ID=80705270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111588304.0A Pending CN114215035A (en) | 2021-12-23 | 2021-12-23 | Static sounding probe combined with TDR technology, detection system and measurement method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114215035A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593535A (en) * | 2023-05-19 | 2023-08-15 | 中国矿业大学 | Miniature resistivity probe for detecting soil pollution concentration and detection method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB201303187D0 (en) * | 2012-02-24 | 2013-04-10 | Mobrey Ltd | Improvements in or relating to interface detection |
| CN108867606A (en) * | 2018-08-15 | 2018-11-23 | 中国人民解放军军事科学院国防工程研究院 | Geological exploration technique before a kind of Foundation Pit Construction based on TDR technology |
| CN110331709A (en) * | 2019-05-27 | 2019-10-15 | 宁波大学 | A kind of hole pressure touching methods probe |
| CN111965221A (en) * | 2020-06-17 | 2020-11-20 | 浙江大学 | Intelligent detection system and method for rapidly acquiring muck engineering property and pollution property |
| CN113167780A (en) * | 2019-03-11 | 2021-07-23 | 建屋发展局 | Apparatus, system and method for classification of soil and soil type |
-
2021
- 2021-12-23 CN CN202111588304.0A patent/CN114215035A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB201303187D0 (en) * | 2012-02-24 | 2013-04-10 | Mobrey Ltd | Improvements in or relating to interface detection |
| CN108867606A (en) * | 2018-08-15 | 2018-11-23 | 中国人民解放军军事科学院国防工程研究院 | Geological exploration technique before a kind of Foundation Pit Construction based on TDR technology |
| CN113167780A (en) * | 2019-03-11 | 2021-07-23 | 建屋发展局 | Apparatus, system and method for classification of soil and soil type |
| CN110331709A (en) * | 2019-05-27 | 2019-10-15 | 宁波大学 | A kind of hole pressure touching methods probe |
| CN111965221A (en) * | 2020-06-17 | 2020-11-20 | 浙江大学 | Intelligent detection system and method for rapidly acquiring muck engineering property and pollution property |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116593535A (en) * | 2023-05-19 | 2023-08-15 | 中国矿业大学 | Miniature resistivity probe for detecting soil pollution concentration and detection method |
| CN116593535B (en) * | 2023-05-19 | 2023-10-20 | 中国矿业大学 | Miniature resistivity probe for detecting soil pollution concentration and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104793264A (en) | Geological condition real-time reflecting and advance detecting system and geological condition real-time reflecting and advanced detecting method applied to drilling rig | |
| CN103174122B (en) | Lateral stress pore pressure probe used for testing soil static lateral pressure coefficient | |
| CN213239507U (en) | Thin-wall soil sampler for in-situ determination of water content of cohesive soil | |
| CN105092815B (en) | The rock acoustics and electrical parameter joint test device of a kind of simulant bearing conditions of coal seam | |
| CN107882011B (en) | miniature probe with temperature compensation function | |
| CN114215035A (en) | Static sounding probe combined with TDR technology, detection system and measurement method | |
| CN103343530B (en) | The micro-scale pores pressure static sounding probe of the very thin soil layer of a kind of effective identification | |
| CN104931353B (en) | Coal column plastic zone method of testing and test device | |
| CN102943458A (en) | Device based on resistivity piezocone penetration test and saturated sandy soil dilatancy evaluation method | |
| CN203307792U (en) | Micro-scale pore pressure static sounding probe for effectively identifying ultra-thin soil layer | |
| CN103255757A (en) | Energy environment static sounding probe capable of measuring deep soil temperatures | |
| CN103116189A (en) | In-situ continuous penetrating probe used in non-aqueous phase liquids (NAPLs) polluted sandy soil field investigation | |
| CN114910367A (en) | Indoor static sounding and bending element combined test system suitable for soil body size strain measurement | |
| CN108593525A (en) | A kind of rock three-dimensional permeability real-time determining device and method | |
| CN105675052A (en) | Multi-parameter testing device and method for stability of underground scope cementing filling body | |
| CN110424362B (en) | Optical fiber type temperature self-compensating static sounding sensor | |
| CN201844991U (en) | Environment pore pressure cone penetration test probe capable of testing dielectric constant of soil body | |
| CN202809591U (en) | Static cone penetration system | |
| CN203361119U (en) | Energy environment static sounding probe capable of measuring temperature of deep soil | |
| CN114544768B (en) | Single-hole ultrasonic detection device and method for continuous integrity and rock entering depth of concrete impermeable wall | |
| CN207123442U (en) | A kind of experimental rig that deep rock-mass deformation is measured by amesdial | |
| CN215105203U (en) | Penetration type acoustic emission static sounding probe | |
| CN102135572A (en) | Environmental pore-pressure cone penetration test probe capable of measuring dielectric constant of soil | |
| CN114544315A (en) | Liquid nitrogen cold leaching real-time temperature measurement and strain measurement system and use method thereof | |
| CN208283233U (en) | A kind of rock three-dimensional permeability real-time determining device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220322 |
|
| RJ01 | Rejection of invention patent application after publication |