CN201635064U - Resistivity static sounding probe - Google Patents

Abstract

The utility model discloses a resistivity static sounding probe. Two annular electrodes (2) are covered on the periphery of the upper half section of the probe; insulating layers (1) are arranged on two sides of each annular electrode (2); a three-component geophone (3) is arranged on the lower half section of the probe; a clinometer (4) is arranged on the lower portion of the three-component geophone (3); a friction drum (5) is arranged below the clinometer (4); a pore water pressure sensor (6) is arranged in the middle of the friction drum (5); the probe (7) is connected below the friction drum (5); and a pore pressure filter ring (8) is positioned at the connecting position of the friction drum (5) with the probe (7). The probe has the advantages of normal position, rapidness, accuracy, economization and the like, and can provide forceful detecting tool for civil engineering foundation treatment practice.

Description

Resistivity static sounding probe

Technical field

The utility model relates to a kind of resistivity static sounding probe, belongs to the static sounding device of a kind of soil layer original position of analytical test continuously resistivity in the geotechnical engineering field.

Background technology

The static sounding technology is meant the sounding rod indentation test soil layer that utilizes pressure apparatus will have contact probe, the static point resistance of throughput examining system test soil, sidewall frictional resistance etc., can determine some basic physico mechanical characteristic of soil, as the modulus of deformation of soil, the allowable bearing of soil etc.The static sounding technology is the history in existing more than 80 year so far.The extensive use static sounding has partly or entirely replaced probing and the sampling in the engineering investigation in the world.China at first succeeded in developing the electric measuring type static sounding and is applied to prospecting in nineteen sixty-five.Along with the fast development of sensor technology, a lot of new static sounding technology occurred in recent years, these technology can obtain pore water pressure, seismic wave, pollutant proterties, temperature even the image of soil layer quickly and accurately.It has been widely used in the environmental geotechnical field abroad.China starts to walk than later in the research of novel static sounding sensor, penetration resistance or specific penetration resistance that present domestic widely used single doube bridge static sounding only can be tested, and the sidewall frictional resistance, the basic physico mechanical characteristic of confirmable soil layer is very limited.

Summary of the invention

Technical problem: the technical problems to be solved in the utility model is the defective that exists at the quiet spy technology of domestic existing single doube bridge, proposes a kind of resistivity static sounding probe that the ground treatment effect detects that is used for.

Technical scheme: the periphery of resistivity static sounding probe upper semisection of the present utility model is surrounded by two annular electrodes, is insulating layer in the both sides up and down of annular electrode; Be provided with 3-component earthquake detector at this probe lower semisection, bottom at 3-component earthquake detector is provided with inclinometer, friction cylinder is positioned at the below of inclinometer, middle part at friction cylinder is provided with pore water pressure sensor, be connected with probe below friction cylinder, hole press filtration ring is positioned at the junction of friction cylinder and probe.

The cone angle of probe is 60 °, and the awl basal cross section is long-pending to be 10cm ², friction cylinder surface area 150cm ²

Hole press filtration ring thickness 5mm is positioned at awl shoulder position, and the effective area ratio of probe is 0.8.

Resistivity static sounding probe of the present utility model, its resistivity measurement part mainly is made up of two copper annular electrodes and inner institutes such as Circuits System.Keep apart with ambroin between the copper electrode, form O shape annular seal system.Measure inner two interelectrode voltage change synchronously, continuously by its inner Circuits System and two electrodes, and calculate the resistivity size of electrode surrounding soil.

Beneficial effect: because resistivity static sounding probe is surveyed native original position resistivity is one of basic parameter of soil, and closely related with structure, void ratio, water content and the composition etc. of soil, its variation can effectively reflect the variation of soil body fundamental characteristics parameter.Therefore can carry out the evaluation of ground treatment effect by the difference of resistivity before and after the contrast ground stabilization, this technology has continuity, reliability and repeatable characteristics.

Before and after supposing that ground is handled, soil nature parameter a and cementation factor m remain unchanged, and porosity be (in the formula ' after the processing of expression ground value) than n '/n before and after handling according to Archie model definition ground:

n′/n＝((ρ′/ρ)·(ρ _w?/ρ _w′)) ^-1/m

In the formula, n ' handles the porosity of back soil for ground; N is the porosity of soil before ground is handled.

Be used in the resistivity static sounding on-the-spot test, the m value of underground water resistivity measurement and hypothesis can be used for estimating the porosity ratio that ground is handled front and back soil.The porosity of sand had reduced after for example ground was handled, and it is closely knit that ground becomes.The big zone of disturbing influence in the probe penetration process, the size of volumetric strain and distribute change along with compactness and stress level, and both all are improved the actual measurement proof after ground is handled.The change of resistivity has obtained confirmation before and after another one vibration displacement place reinforces.

Description of drawings

Fig. 1 is measuring principle figure of the present utility model;

Wherein have: ambroin 1, annular electrode 2,3-component earthquake detector 3, inclinometer 4, friction cylinder 5, pore water pressure sensor 6, probe 7, hole press filtration ring 8.

The specific embodiment

The periphery of resistivity static sounding probe upper semisection of the present utility model is surrounded by two annular electrodes 2, is insulating layer 1 in the both sides of annular electrode 2; Be provided with 3-component earthquake detector 3 at this probe lower semisection, be provided with inclinometer 4 in the bottom of 3-component earthquake detector 3, friction cylinder 5 is positioned at the below of inclinometer 4, be provided with pore water pressure sensor 6 at the middle part of friction cylinder 5, be connected with probe 7 below friction cylinder 5, hole press filtration ring 8 is positioned at the junction of friction cylinder 5 and probe 7.The cone angle of probe 7 is 60 °, and the awl basal cross section is long-pending to be 10cm ²

This probe is integrated function of conventional static sounding (can survey end resistance, frictional resistance, inclination and hole presses) and native resistivity measurement function.The resistivity of soil is the basic parameter that characterizes soil body electric conductivity, is one of intrinsic physical parameter of soil, depends on native porosity, pore shape, hole liquid resistivity, saturation ratio, solid particle composition, shape, directionality, cementing status etc.The Changing Pattern of the physical mechanical property index of the Changing Pattern reflection soil body of soil resistivity and index of correlation thereof.Therefore, can be used for the assessment of ground treatment effect based on the resistivity static sounding technology.The core of resistivity static sounding probe equipment is a resistivity sensor, and probe adopts four configuration of electrodes, to eliminate the error that gas takes place and plating may cause.Probe has a special electric servo system, uses automatic correction technique to guarantee measuring accuracy in 0～10000ms/s scope.The probe specification meets international standard: 60 ° of cone angles, the awl basal cross section is long-pending to be 10cm ², sidewall friction tube area 150cm ²

3-component earthquake detector 3: model is m317259, intrinsic frequency 100HZ/60HZ, sensitivity 104mV/kine, impedance 215 Ω.

Gyrolevel 4: drift angle measurement category: 0 °～15 °; Precision: ± 0.1 °; Drift angle resolution ratio: 0.01 °;

Be illustrated in figure 1 as the schematic diagram of measurement.Because the complexity of electric field in the soil around the feeler lever, and fringe conditions is restive, makes by the measured native electrical characteristic of probe very complicated.Drawn the theoretical equation of cone penetration test by Ohm's law, native resistivity is by two interelectrode voltage drop Δ V under the test constant current, and calculate to be unearthed according to Ohm's law that the size of resistance R draws.The vertical electricalresistivity of sample can be expressed as:

$\mathrm{\ρ}=\frac{\mathrm{RS}}{L}=\frac{\mathrm{\ΔVS}}{\mathrm{IL}}$

In the formula, S is electrode area (m ²), L is electrode spacing (m), I is current strength (A).

Because the complexity of fringe conditions, the electrical characteristic of the soil of feasible probe gained is very complicated.Drawn the theoretical equation of cone penetration test by Ohm's law:

ρ＝π ²ΔV/(CI)

In the formula, C=1/ (d+r _M)-1/ (d+r-r _M)-1/ (d+r _N)+1/ (d+r-r _N), ρ is the resistivity of soil, and Δ V is a voltage difference, and I is an electric current.

Claims (3)

1. a resistivity static sounding probe is characterized in that being surrounded by two annular electrodes (2) in the periphery of this probe upper semisection, is insulating layer (1) in the both sides up and down of annular electrode (2); Be provided with 3-component earthquake detector (3) at this probe lower semisection, be provided with inclinometer (4) in the bottom of 3-component earthquake detector (3), friction cylinder (5) is positioned at the below of inclinometer (4), be provided with pore water pressure sensor (6) at the middle part of friction cylinder (5), be connected with probe (7) in the below of friction cylinder (5), hole press filtration ring (8) is positioned at the junction of friction cylinder (5) and probe (7).

2. resistivity static sounding probe according to claim 1 is characterized in that the cone angle of probe (7) is 60 °, and the awl basal cross section is long-pending to be 10cm ², friction cylinder surface area 150cm ²

3. resistivity static sounding probe according to claim 1 is characterized in that hole press filtration ring (8) thickness 5mm, is positioned at awl shoulder position, and the effective area ratio of probe is 0.8.

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