Patent ID: 12188889

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention is further illustrated in detail in the light of the drawings and embodiments as follows.

As shown inFIG.1andFIG.2, the system embodiment of the present invention comprises at least a set of electrode1(four probes), a data integration apparatus10used for intelligently measuring water content, a constant current source11as an electric source, and a visible mobile device12facilitating data acquisition in real time and sending operation command instruction, wherein the probe1and the constant current source11are all electrically connected with the data integration apparatus10via wire7. The data integration apparatus10has a built-in wireless communication module which is in wireless communication connection with the visible mobile device12.

In order to clearly describe the contact condition between the probes and the subgrade soil,FIG.1also shows the subgrade soil13. When measuring water content, the four probes1are fully contact with the subgrade soil13measured due to the protrusion of top end (outer end).

A set of electrode1comprises four probe a, b, c and d, all of which have a certain strength. They are fixed on the scroll roller8of the road compacting machine through preset holes, which can bear the pressure during the machine's moving process and the vibration pressure during the vibration compaction. Moreover, the top of each probe1has a circular protrusion of 1-2 mm to ensure full contact with the subgrade soil13. Preferably, the detection parts of the four probes are arranged in a straight line arrangement and equidistantly arranged on the scroll roller8.

As detailed inFIG.2, an insulation isolation layer2is provided between the probe a, probe b, probe c, probe d and the preset holes of the scroll roller8, the arrangement direction of the detection parts of the four probes is parallel to the axis of the scroll roller8; The insulation isolation layer2adopts a hard insulation material such as Teflon or the like. The extending part of the outer ends of probe a, probe b, probe c and probe d protruding out of the inner surface of scroll roller8is firstly provided with insulation gasket3which is fixed by nut4. Next, the wire terminal5is configured, and then the wire terminal5is fixed by nut6and is connected with one end of a signal wire7, and the four signal wires7are a plurality of twisted copper wires in a four core shielding cable. Probe a, probe b, probe c and probe d are parallel distributed on the scroll roller8. Preferably, the distance between the adjacent probes in the four probes is equidistantly spaced, and the connecting line of the four probes is parallel to the axis of the scroll roller8, so as to ensure that the four probes1simultaneously touch the subgrade soil13.

Preferably, within the test influence range of 100 cm long and 50 cm wide of outer surface of scroll roller8, except for the outer end surface of probe1, an insulation coating14with thickness of about 2 mm shall be applied onto other range to eliminate the influence of the outer surface of scroll roller8on the test potential Certainly, the insulation coating14of the other range may also be an option.

Further, the signal wire7is placed into the hard PE pipe to avoid exposure, and the hard PE pipe is arranged on the inner surface of the scroll roller8with a clamp.

Furthermore, the probe1is a titanium-iron alloy with good conductivity, and its cross section adopts a special shape: the diameter of the outer part is large, the diameter of the inner part is small, which is conducive to bear the impact vibration pressure and maintain the full contact between the probe1and the subgrade soil13. Each probe1is a screw-rod structure. The length of each probe1is 60 mm, the diameter of its lateral section is 20 mm, the diameter of its inner section is 6 mm. The length of its outer side is 12 mm, the length of its inner side is 48 mm, the length of the part extending out of its inner surface of the scroll roller8is 20 mm, and the length of its thread part is 20 mm.

Further, the outer insulation layer of probe1also adopts a specially-made shape. In order to reduce the impact of shear damage at the contact place between the insulation layer and the probe, the transition form is appropriately changed.

Furthermore, an insulation gasket3is firstly provided to prevent the probe from forming an equipotential body on the inner surface extending out of the scroll roller8.

Next, the nut4, the wire terminal5and the nut6are successively configured. The wire terminal5is ring shape of copper and is welded with the signal wire7.

The signal wire7connecting the probe1and the data integration apparatus10is preferably an enameled wire made of single-branch multi-stranded pure copper wire, and the specific specification of which is preferably 4×0.75 individual shielding signal wire. The outer side of each shielding wire is copper winding wire which improves the individual shielding ability. The outer side is protected by silicone rubber, the total thickness of 0.3 mm thereof, to ensure the high strength, superconductivity and high flexibility of the cable.

The test signal of the test probe1converges at the signal input port of the data integration apparatus10via the wire7. The data integration apparatus10has the functions of test data acquisition, calculation, analysis and wireless transmission of water content of subgrade soil. The internal part of the data integration apparatus10is preferably an integrated circuit, which mainly comprises a standard electric resistance, a voltmeter, an ammeter (devices necessary for the implementation of the Wenner's theory), and a wireless transmission module in addition. The voltmeter determines the electric potential of the standard electric resistance and the electric resistance of probes b, probe c contacting the subgrade soil13. The ammeter determines the electric current passing through electric resistance of the subgrade soil, and the wireless transmission module transmits the data to the visible mobile device12. The constant current source11is preferably a nickel hydrogen battery, and is connected with the data integration apparatus10through electric conductive joint9for providing a constant current to the data integration apparatus10. However, the visible mobile device12is provided with a built-in application program APP (the development process of APP commonly used by the mobile devices has been mature, and the detailed will not be described herein). After authorization and approval, it is possible of measuring water content of subgrade soil13by clicking on “continuous test”.

The APP for measuring water content can provide two buttons. The “connection device” provides function of real-time connection authorization, and the “continuous measurement” provides the function of automatically computing data into Resistivity folder. Display interface of water content can realize real-time visualization of the water content.

The data integration apparatus10and the constant current source11are both placed in a resin square box with a suitable size, wherein the two ends of the box wall of the data integration apparatus10are respectively provided with preset holes, while the one end of the box wall of the constant current source11is only provided with preset holes which is specially used for fixing the electric conductive joint9, preferably is a four-wired joint. The two square boxes are fixed onto the inner surface of scroll roller8by a clamp.

In the embodiment of present invention, the soil electrical resistivity is tested according to the Wenner's theory. Probe a, probe b, probe c and probe d are inserted into scroll roller8of road compacting machine. When the probes contact soil, the constant current is applied between probe a and probe d, and a voltage is generated on the standard electric resistance and the other two electrodes, according to the theory. The detailed operation steps are as follows:

Following the scroll roller of road compacting machine's moving process, when probe a, probe b, probe c and probe d contact subgrade soil13with different water content, the visible mobile device12is connected, clicking on the “continuous measurement” command button to connect probe a and probe d with the constant current source11, and measuring the potential difference Us at both ends of the standard electric resistance Rs and the voltage Ubc between probe c and probe c through the voltmeter of the data integrated circuit10. From this, the test electric resistance can be calculated by the following formula:

Rt=Ub⁢cUsRsρ can be obtained according to the formula:

ρ=dab(dab+dbc)db⁢c⁢π⁢RtGenerally, dab=dcd=ndbcwhere n is a positive integer; the electrical resistivity of subgrade soil P is calculated out by programming in integrated circuits,Due to the relationship between the electrical resistivity of soil body and water content is affected by air temperature, the present invention established relationship formula between electric resistivity and water content relationship considering the influence of temperature as follows:
ω=aln[b(0.45+1.4e−t/27)ρ]

Among them, a,b is the relation parameters of electrical resistivity and water content affected by different soil properties, is necessary to carry out calibration test of soil samples with no less than four equal differential water content (such as 4%, 6%, 8%, 12%) under a predetermined compaction at room temperature of 25 degree before construction to determine the parameters a,b; t is the air temperature in real time during compaction, the specific specification of which is ° C.; ρ is the electrical resistivity of soil body obtained through the test of the present invention.

Finally, the water content of the subgrade is determined according to the corresponding relationship between pre-calibrated electric resistivity and water content of soil body, so as to obtain the water content of the subgrade soil at any position of the subgrade which is saved in the Resistivity folder for uploading and summarizing.

In conclusion, the present invention has achieved a continuous intelligent test of subgrade water content in real time based on the Wenner's theory due to the adoption of the probes with a certain hardness possible of which directly contact subgrade soil under the vibration load. The test precision of water content of subgrade soil is greatly improved. It has the advantages of a real-time, continuous, non-destructive damage, visualization and the like. Further it combines water content with the intelligent compaction system. In particular, the shape design of the probes is reasonable, and the insulation property between the probes and scroll roller is good.

The influence of test error is reduced. The mobile equipment can control the test system remotely, further control the compaction quality. The operation of the present invention is simple and the test range is no long limited. The quality control level of subgrade compaction is tremendously improved.

It can be known from the general technical knowledge that the present invention can be realized by other embodiments without departing from its spiritual essence or necessary features thereof. Therefore, the disclosed above-mentioned embodiments are only examples for explanation in various aspects, not the only ones. All changes within the scope of the present invention or within the equivalent scope of the present invention are all encompassed in the present invention.