阅读说明：本技术 一种海底沉积物力学特性与浅层气综合检测装置 (Comprehensive detection device for mechanical characteristics and shallow gas of submarine sediments ) 是由 李青 童仁园 贾生尧 郑俊杰 屠烟波 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种海底沉积物力学特性与浅层气综合检测装置。包括海底沉积物力学特性检测部分、浅层气检测部分和超声无线信号传输部分,海底沉积物力学特性检测部分、浅层气检测部分分别测量力学参数和海底浅层气甲烷浓度,超声无线信号传输部分用超声换能器将海底沉积物力学参数跨越泥水分离室和气水分离室送至在气体检测室的超声换能器；再经在气体检测室内的浅层气测量和海底沉积物力学参数收发电路以总线方式送至海上计算机。本发明能同时在线检测海底沉积物力学特性和浅层气,并利用超声波和FSK调制实现了不能用电缆数据传输部分的无线信号传输,跨越泥水气分离结构进行无线通信,检测准确性高,大大提升了海洋工程的效率。(The invention discloses a comprehensive detection device for mechanical characteristics and shallow gas of submarine sediments. The system comprises a mechanical property detection part of the submarine sediment, a shallow layer gas detection part and an ultrasonic wireless signal transmission part, wherein the mechanical property detection part of the submarine sediment and the shallow layer gas detection part respectively measure mechanical parameters and the methane concentration of the submarine shallow layer gas, and the ultrasonic wireless signal transmission part uses an ultrasonic transducer to transmit the mechanical parameters of the submarine sediment to the ultrasonic transducer in a gas detection chamber by crossing a mud-water separation chamber and the gas-water separation chamber; and then the gas is transmitted to an offshore computer in a bus mode through a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit in a gas detection chamber. The invention can simultaneously detect the mechanical property and shallow gas of the submarine sediment on line, realizes wireless signal transmission of a part which can not use cable data transmission by using ultrasonic waves and FSK modulation, carries out wireless communication across a mud-water-gas separation structure, has high detection accuracy and greatly improves the efficiency of ocean engineering.)

1. The utility model provides a submarine sediment mechanical properties and shallow layer gas integrated detection device which characterized in that:

the system mainly comprises a mechanical property detection part of the submarine sediments, a shallow gas detection part and an ultrasonic wireless signal transmission part, wherein the mechanical property detection part of the submarine sediments realizes the measurement of mechanical parameters of the soil body pressure, the side wall friction force and the pore water pressure of the submarine sediments, the shallow gas detection part realizes the measurement of the concentration of submarine shallow gas methane, and the ultrasonic wireless signal transmission part sends the mechanical parameters of the submarine sediments to a signal receiving ultrasonic transducer in a gas detection chamber by a signal sending ultrasonic transducer in a way of crossing a mud-water separation chamber and a gas-water separation chamber; the methane concentration of shallow gas and the mechanical parameters of the seabed sediments are transmitted to an upper computer on a sea surface ship in a bus mode through a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit in a gas detection chamber.

2. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 1, is characterized in that: the mechanical property detection part of the submarine sediments and the shallow gas detection part form a comprehensive detection structure of mechanical properties and shallow gas; the comprehensive detection structure for mechanical properties and shallow gas comprises a multifunctional piezocone penetration test probe (1), a reducing joint (2), a mud-water separation chamber (3), a gas-water separation chamber (4), a gas detection chamber (5), an adapter (6), a compression gasket (7) and a sealing head (8); the multifunctional piezocone penetration test device comprises a multifunctional piezocone penetration test probe (1), a mud-water separation chamber (3), a gas-water separation chamber (4), a gas detection chamber (5) and a sealing head (8), which are coaxially arranged from bottom to top, wherein a shallow gas detection part is mainly formed by the mud-water separation chamber (3), the gas-water separation chamber (4) and the gas detection chamber (5), and a mechanical property detection part of a seabed sediment is mainly formed by the multifunctional piezocone penetration test probe (1); the upper end of the multifunctional piezocone penetration test probe (1) is connected with the lower end of a mud-water separation chamber (3) into a whole through a reducer union (2), the upper end of the mud-water separation chamber (3) is coaxially connected with the lower end of a gas-water separation chamber (4), the upper end of the gas-water separation chamber (4) is connected with the upper end of a gas detection chamber (5), the upper end of the gas detection chamber (5) is coaxially connected with a sealing head (8) through an adapter (6), and compression gaskets (7) are respectively arranged between the upper end and the lower end of the gas-water separation chamber (4) and the adapter (6);

the mud-water separation chamber (3) is cylindrical, a water-permeable ceramic pipe is arranged in the mud-water separation chamber, four rectangular windows (3.1) are formed in the outer wall of the mud-water separation chamber at intervals along the circumference, and porous ceramic or water-permeable stones are embedded in the rectangular windows (3.1);

the gas-water separation chamber (4) is cylindrical, an annular inner boss (4.1) is arranged on the inner wall of the middle part of the gas-water separation chamber, a plurality of small holes are formed in the annular inner boss (4.1), a permeable membrane is placed on the annular inner boss (4.1), and a pressing gasket with the same small holes is used for pressing the permeable membrane;

the gas detection chamber (5) is cylindrical, an annular inner flange (5.1) is arranged on the inner wall of the lower part, a waterproof breathable film is placed in a hole formed by the annular inner flange (5.1), and seawater does not enter the gas detection chamber through the waterproof breathable film and damage a sensor and a detection circuit; a non-dispersive infrared methane sensor is arranged in the gas detection chamber (5).

3. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 2, wherein: the multifunctional piezocone penetration test probe (1) comprises a connecting rod (1.1), a friction cylinder (1.2), a through hole (1.3), a pore water pressure sensor (1.4), a water permeable hole (1.5), a water permeable filter (1.6), a conical head (1.7), a second deformation column (1.8), an upper group of strain gauges, a lower group of strain gauges, a friction cylinder inner step (1.10), a first deformation column (1.11) and a water permeable blind hole (1.12);

the upper end of a connecting rod (1.1) is inserted and fixed to the lower end of the reducer union (2), the upper ends of a second deformation column (1.8) and a friction cylinder (1.2) are fixed to the lower end of the connecting rod (1.1), and a first deformation column (1.11) and a second deformation column (1.8) are sleeved in the friction cylinder (1.2); the first deformation column (1.11) is sleeved in the friction cylinder (1.2) firstly, the lower part of the first deformation column (1.11) is provided with an upper annular conical outer flange and a lower annular conical outer flange, the lower part of the friction cylinder (1.2) is provided with an upper annular inner flange and a lower annular inner flange, the two annular conical outer flanges are sleeved in the two annular inner flanges respectively, and the outer cylindrical surface between the two annular conical outer flanges of the first deformation column (1.11) is provided with a lower group of strain gauges; a second deformation column (1.8) is sleeved outside the first deformation column (1.11) above the annular conical outer flange, two annular outer flanges are respectively arranged on the outer cylindrical surfaces of the upper end and the lower end of the second deformation column (1.8), an upper group of strain gauges are arranged on the outer cylindrical surface between the two annular outer flanges of the second deformation column (1.8), and the lower end surface of the annular outer flange of the lower end of the second deformation column (1.8) is connected to a friction barrel inner step (1.10) formed by the annular conical outer flange on the first deformation column (1.11) and the annular inner flange on the friction barrel (1.2) in a matched manner; a through hole (1.3) is formed in the center of a first deformation column (1.11), a conical head (1.7) is coaxially and fixedly installed at the lower port of the through hole (1.3) of the first deformation column (1.11), the upper end of the conical head (1.7) extends into the through hole of the first deformation column (1.11) and is provided with a vertical water permeable blind hole (1.12) on the top end face, the lower end of the conical head (1.7) is a conical body, a horizontal water permeable hole (1.5) is formed in the top of the lower end of the conical head (1.7), the conical head (1.7) at the outer end of the water permeable hole (1.5) is connected with a water permeable filter (1.6), the inner end of the water permeable hole (1.5) is communicated with the bottom of the water permeable blind hole (1.12), a pore water pressure sensor (1.4) is installed at the top end of the water permeable blind hole (1.12), external water enters the water permeable hole (1.5) through the water permeable blind hole (1.6), and then flows into the pore pressure sensor (1.

4. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the upper group of strain gauges and the lower group of strain gauges are respectively composed of four strain gauges (1.9) which are uniformly distributed at intervals along the circumference, and the four strain gauges (1.9) are connected in a bridge structure to form the piezoresistive pressure sensor.

5. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the strain gauge (1.9) and the pore water pressure sensor (1.4) are connected with an external power supply through an 8-core cable.

6. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the strain gauge (1.9) and the pore water pressure sensor (1.4) are connected to the output voltage value of the singlechip through respective small signal amplification circuits to obtain respective final acquisition signals; the small signal amplifying circuit comprises an operational amplifier chip AD620 and an operational amplifier chip AD705, wherein a positive phase input end and a negative phase input end of the operational amplifier chip AD620 are connected with two output ends of a strain gauge (1.9)/pore water pressure sensor (1.4), a reference voltage end of the operational amplifier chip AD620 is connected with an output end and a negative phase input end of the operational amplifier chip AD705, the positive phase input end of the operational amplifier chip AD705 is connected with the ground through a resistor, and the output end of the operational amplifier chip AD620 outputs a final acquisition signal.

7. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the ultrasonic wireless transmission part comprises an emitting ultrasonic transducer and a receiving ultrasonic transducer, wherein the emitting ultrasonic transducer is arranged on the inner wall of the reducer union (2) and is electrically connected with the output end of the single chip microcomputer of the mechanical property detection part of the seabed sediments; the receiving ultrasonic transducer is arranged on the inner wall of the gas detection chamber (5) and is electrically connected with an upper computer on the sea surface; the device adopts an ultrasonic wireless signal transmission mode, converts digital signals measured by a mechanical property detection part of the submarine sediments into analog signals suitable for being transmitted in a mud-water-gas separation structure of a shallow gas detection part through FSK modulation, drives a transmitting transducer to send out acoustic signals, converts electric signals into acoustic signals, and transmits the acoustic signals in a device shell; after the receiving ultrasonic transducer receives the acoustic signal, the collected acoustic signal is converted into an electric signal, and original signal information in the digital signal is recovered through demodulation and decoding.

8. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the transmitting ultrasonic transducer is packaged in the reducing joint (2), is powered by a battery and specifically adopts a piezoelectric transducer.

9. The comprehensive detection device for mechanical properties of seabed sediments and shallow gas as claimed in claim 3, is characterized in that: the analog signal is modulated in the following way: two unipolar sine wave signals with different frequencies are respectively generated by two direct digital frequency synthesis (DDS) modules, the two unipolar sine wave signals are respectively connected to a second phase inverter through respective analog switches, the modulation end of one analog switch is connected to a baseband signal, the modulation end of the other analog switch is connected to the baseband signal through a first phase inverter, the FSK modulated signal output by the second phase inverter is transmitted to the input end of an amplifying circuit, the output end of the amplifying circuit is connected to an ultrasonic transducer, the two analog switches gate one of the two unipolar sine wave signals under the control of a microprocessor, so that the two unipolar sine wave signals alternately output the FSK modulated signal along a time sequence, and the FSK modulated signal is amplified by the amplifying circuit and then drives an ultrasonic transducer to generate an ultrasonic sound signal; the amplifying circuit comprises an operational amplifier THS4001, a positive phase input end of the operational amplifier THS4001 is connected with an output end of a second inverter through a first capacitor, an opposite phase input end of the operational amplifier THS4001 is grounded through a first resistor, a second resistor and a second capacitor are connected between the opposite phase input end and the output end of the operational amplifier THS4001 in parallel, and an output end of the operational amplifier THS4001 outputs an analog signal through a third resistor.

Technical Field

The invention relates to a submarine measurement and detection instrument, in particular to a submarine sediment mechanical property and shallow gas comprehensive detection device.

Background

With the development of economy and science, the oceans with abundant physical and chemical resources become hot spots for resource development in a new period. No matter resource mining or infrastructure construction, marine engineering facility construction cannot be left, wherein the determination of the basic physical and mechanical properties, the foundation bearing capacity and the like of the seabed soil body is an important test project for marine engineering investigation. In addition, shallow gas is widely distributed in the near gulf area, and the shallow gas on the seabed generally refers to natural gas resources accumulated in sediments under the seabed, and the main component of the shallow gas is methane gas. The leakage and eruption of shallow gas on the seabed can cause the construction platform to sink, overturn and cause fire, seriously threatens the life safety of constructors and causes great harm to ocean engineering construction. Therefore, research on mechanical characteristics of the submarine sediments and a comprehensive detection device for shallow gas becomes an urgent need for marine energy development and engineering construction in China.

At present, the mechanical characteristics of the seabed sediments are generally detected by adopting a static sounding technology, a probe is pressed into the sediments at a constant speed through hydraulic pressure, and three parameters which represent the physical and mechanical properties of the seabed sediments are measured through a strain sensitive element in the penetration process: cone head resistance, sidewall friction, and pore water pressure.

The main method commonly adopted for detecting the shallow gas in China at present is an exploration drilling method, the method mainly comprises the steps of collecting a sample rich in the shallow gas through a probe rod, then extracting the shallow gas in a laboratory, and finally measuring each gas component in the shallow gas by using a gas chromatograph. And the mechanical property detection and the shallow gas detection of the submarine sediments in engineering are separately detected, so that the labor and the time are wasted, the cost is very high, and even the shallow gas detection is not carried out for some time, so that huge hidden dangers are left.

Therefore, the prior art lacks a device and a method for simultaneously detecting the mechanical properties of the submarine sediments and shallow gas.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a comprehensive detection device for the mechanical properties of the submarine sediments and the shallow gas, which realizes the simultaneous comprehensive detection of the mechanical properties of the submarine sediments and the shallow gas.

The technical scheme adopted by the invention is as follows:

the system mainly comprises a mechanical property detection part of the submarine sediments, a shallow gas detection part and an ultrasonic wireless signal transmission part, wherein the mechanical property detection part of the submarine sediments is connected with an upper computer on the external sea surface through the ultrasonic wireless transmission part; the methane concentration of shallow gas and the mechanical parameters of the seabed sediments are transmitted to an upper computer on a sea surface ship in a bus mode through a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit in a gas detection chamber.

The mechanical property detection part of the submarine sediments and the shallow gas detection part form a comprehensive detection structure of mechanical properties and shallow gas; the comprehensive detection structure for mechanical properties and shallow gas comprises a multifunctional piezocone penetration test probe, a reducer union, a mud-water separation chamber, a gas detection chamber, an adapter, a compression gasket and a sealing head; the multifunctional piezocone penetration test device comprises a multifunctional piezocone penetration test probe, a mud-water separation chamber, a gas detection chamber and a sealing head which are coaxially arranged from bottom to top, wherein the mud-water separation chamber, the gas-water separation chamber and the gas detection chamber mainly form a shallow gas detection part, and the multifunctional piezocone penetration test probe mainly forms a mechanical property detection part of a submarine sediment; the upper end of the multifunctional piezocone penetration test probe is connected with the lower end of the mud-water separation chamber into a whole through the reducer union, the upper end of the mud-water separation chamber is coaxially connected with the lower end of the gas-water separation chamber, the upper end of the gas-water separation chamber is coaxially connected with the upper end of the gas-water detection chamber, the upper end of the gas-water detection chamber is coaxially connected with the sealing head through the adapter, and the upper end and the lower end of the gas-water separation chamber are respectively provided with.

The mud-water separation chamber is cylindrical, a water-permeable ceramic pipe is arranged in the mud-water separation chamber, four rectangular windows which are uniformly distributed at intervals along the circumference are formed in the outer wall of the mud-water separation chamber, and porous ceramic or water-permeable stones are embedded in the rectangular windows; the gas-water separation chamber is cylindrical, an annular inner boss is arranged on the inner wall of the middle part of the gas-water separation chamber, a plurality of small holes are formed in the annular inner boss, a permeable membrane is placed on the annular inner boss, and a pressing gasket with the same small holes is used for pressing the permeable membrane; the gas detection chamber is cylindrical, an annular inner flange is arranged on the inner wall of the lower part of the gas detection chamber, a waterproof breathable film is placed in a hole formed by the annular inner flange, and seawater does not enter the gas detection chamber through the waterproof breathable film and damage a sensor and a detection circuit; the gas detection chamber is internally provided with a non-dispersive infrared methane sensor, an ultrasonic signal receiving transducer, a non-dispersive infrared methane sensor, a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit.

The multifunctional piezocone penetration test probe comprises a connecting rod, a friction cylinder, a through hole, a pore water pressure sensor, a water permeable hole, a water permeable filter, a conical head, a second deformation column, an upper strain gauge group, a lower strain gauge group, a step inside the friction cylinder, a first deformation column and a water permeable blind hole; the upper end of the connecting rod is fixedly inserted into the lower end of the reducer union, the upper ends of the second deformation column and the friction cylinder are fixedly arranged at the lower end of the connecting rod, and the first deformation column and the second deformation column are sleeved in the friction cylinder; the first deformation column is sleeved in the friction cylinder, the lower part of the first deformation column is provided with an upper annular conical outer flange and a lower annular conical outer flange, the lower part of the friction cylinder is provided with an upper annular inner flange and a lower annular inner flange, the two annular conical outer flanges are respectively sleeved and assembled in the two annular inner flanges, and the lower group of strain gauges are arranged on the outer cylindrical surface between the two annular conical outer flanges of the first deformation column; a second deformation column is sleeved outside the first deformation column above the annular conical outer flange, two annular outer flanges are respectively arranged on the outer cylindrical surfaces of the upper end and the lower end of the second deformation column, an upper group of strain gauges are arranged on the outer cylindrical surface between the two annular outer flanges of the second deformation column, and the lower end surface of the annular outer flange of the lower end of the second deformation column is connected to a friction barrel inner step formed by the annular conical outer flange on the first deformation column and the annular inner flange on the friction barrel in a matched mode; the through-hole is seted up at first deformation post center, the coaxial fixed mounting of port has the conical head under the through-hole of first deformation post, the conical head upper end stretches into in the through-hole of first deformation post and sets up the vertical blind hole that permeates water at the top terminal surface, the conical head lower extreme is the conical body, the top of conical head lower extreme is seted up the horizontally hole of permeating water, the outer end of the hole of permeating water runs through the department conical head and connects and install the filter that permeates water, the inner of the hole of permeating water and the bottom intercommunication of the blind hole of permeating water, the blind hole top of permeating water installation pore water pressure sensor, outside moisture gets into the hole of permeating water through the filter, it detects to flow into pore water pressure.

The upper group of strain gauges and the lower group of strain gauges are respectively composed of four strain gauges which are uniformly distributed at intervals along the circumference, and the four strain gauges are connected in a bridge structure to form the piezoresistive pressure sensor.

The strain gauge and the pore water pressure sensor are connected with an external power supply through an 8-core cable.

The strain gauge and the pore water pressure sensor are connected to the output voltage value of the singlechip through respective small signal amplification circuits to obtain respective final acquisition signals; the small signal amplifying circuit comprises an operational amplifier chip AD620 and an operational amplifier chip AD705, wherein a positive phase input end and a negative phase input end of the operational amplifier chip AD620 are connected with two output ends of the strain gauge/pore water pressure sensor, a reference voltage end of the operational amplifier chip AD620 is connected with an output end and a negative phase input end of the operational amplifier chip AD705, the positive phase input end of the operational amplifier chip AD705 is connected with the ground through a resistor and a power supply voltage, and the output end of the operational amplifier chip AD620 outputs a final acquisition signal.

The ultrasonic wireless transmission part comprises an emitting ultrasonic transducer and a receiving ultrasonic transducer, wherein the emitting ultrasonic transducer is arranged on the inner wall of the reducing joint and is electrically connected with the output end of the singlechip of the mechanical property detection part of the seabed sediments; the receiving ultrasonic transducer is arranged on the inner wall of the gas detection chamber and is electrically connected with an upper computer on the sea surface; the device adopts an ultrasonic wireless signal transmission mode, converts digital signals measured by a mechanical property detection part of the submarine sediments into analog signals suitable for being transmitted in a mud-water-gas separation structure of a shallow gas detection part through FSK modulation, drives a transmitting transducer to send out acoustic signals, converts electric signals into acoustic signals, and transmits the acoustic signals in a device shell; after the receiving ultrasonic transducer receives the acoustic signal, the collected acoustic signal is converted into an electric signal, and original signal information in the digital signal is recovered through demodulation and decoding.

The transmitting ultrasonic transducer is packaged in the reducing joint, is powered by a battery and specifically adopts a piezoelectric transducer.

The analog signal is modulated in the following way: two unipolar sine wave signals with different frequencies are respectively generated by two direct digital frequency synthesis (DDS) modules, the two unipolar sine wave signals are respectively connected to a second phase inverter through respective analog switches, the modulation end of one analog switch is connected to a baseband signal, the modulation end of the other analog switch is connected to the baseband signal through a first phase inverter, the FSK modulated signal output by the second phase inverter is transmitted to the input end of an amplifying circuit, the output end of the amplifying circuit is connected to an ultrasonic transducer, the two analog switches gate one of the two unipolar sine wave signals under the control of a microprocessor, so that the two unipolar sine wave signals alternately output the FSK modulated signal along a time sequence, and the FSK modulated signal is amplified by the amplifying circuit and then drives an ultrasonic transducer to generate an ultrasonic sound signal; the amplifying circuit comprises an operational amplifier THS4001, a positive phase input end of the operational amplifier THS4001 is connected with an output end of a second inverter through a first capacitor, an opposite phase input end of the operational amplifier THS4001 is grounded through a first resistor, a second resistor and a second capacitor are connected between the opposite phase input end and the output end of the operational amplifier THS4001 in parallel, and an output end of the operational amplifier THS4001 outputs an analog signal through a third resistor.

During detection, a hydraulic machine on a ship penetrates the mechanical characteristics of the submarine sediments and the shallow gas comprehensive detection device into the submarine sediments, sediment resistance can cause deformation of a hollow column outside the strain sensitive element, and the strain sensitive element on the hollow column can output three tiny voltages respectively corresponding to three parameters representing the physical and mechanical characteristics of the submarine sediments. Then, the output tiny voltage signal is converted into a digital electric signal through AD sampling, the digital signal is converted into an analog signal suitable for being transmitted in a channel by using a modulator, a transmitting transducer is driven, the electric signal is converted into an acoustic signal, and the acoustic signal enters a wireless channel for transmission; the receiving ultrasonic transducer converts captured acoustic signals into electric signals, original information is recovered through phase-locked loop demodulation and decoding, and therefore the mud-water-gas separation structure is spanned, and the signals are transmitted to the sensor placing chamber.

Meanwhile, solid-liquid separation is realized by utilizing the porous ceramic permeable stone at the lower end of the mud-water-gas separation structure, gas-liquid separation is realized by the macromolecular gas-liquid separation permeable membrane in the structure, and the methane sensor which is positioned in the sensor placing chamber and based on the infrared absorption principle senses shallow gas and outputs a corresponding voltage value.

And finally, the signals measured by the two parts are sent to the marine mother ship through a cable positioned in the sensor placing chamber, so that the comprehensive monitoring of the physical and mechanical properties of the submarine sediments and the shallow gas is realized.

The invention has the beneficial effects that:

the invention realizes the simultaneous comprehensive detection of the mechanical property of the submarine sediment and the shallow gas, can simultaneously detect the mechanical property of the submarine sediment and the shallow gas on line, and realizes the wireless signal transmission of the part which can not use cable data transmission by utilizing ultrasonic waves and FSK modulation.

The data of the invention can span a mud-water-gas separation structure for wireless communication, the detection accuracy is high, the actual requirements are met, the quality of ocean engineering can be improved, the potential safety hazard of shallow gas on construction can be effectively eliminated, the efficiency of ocean engineering is greatly improved, and the invention has wide application prospect and significance.

Drawings

FIG. 1 is a block diagram of the installation arrangement of the apparatus of the present invention;

FIG. 2 is a view showing the overall structure of the apparatus;

FIG. 3 is a structural view of a mud-water separating chamber;

FIG. 4 is a front view of the structure of the gas-water separation chamber;

FIG. 5 is a block diagram of a gas detection chamber;

FIG. 6 is an internal cross-sectional view of the probe of the present invention;

FIG. 7 is a schematic diagram of the bridge configuration of the strain gage of the probe of the present invention;

FIG. 8 is a small voltage signal amplification circuit diagram;

FIG. 9 is a modulation circuit diagram;

FIG. 10 is a schematic diagram of an FSK modulation waveform;

fig. 11 is a drive amplification circuit;

fig. 12 is a block diagram of FSK demodulation logic;

FIG. 13 is a schematic block diagram of shallow gas measurement and seafloor sediment mechanical parameter transceiver circuitry;

FIG. 14 is a schematic diagram of a non-dispersive infrared sensor configuration;

FIG. 15 is a graph of transducer frequency testing;

FIG. 16 is a plot of 45kHz and 90kHz carrier signals;

fig. 17 is a diagram of FSK modulation waveforms;

fig. 18 is an enlarged waveform diagram of an FSK signal;

fig. 19 is an enlarged waveform diagram of an FSK signal;

FIG. 20 is a graph of results of different concentrations of methane concentration tests;

FIG. 21 is a graph of field test experimental data results.

In the figure: the device comprises a multifunctional piezocone penetration test probe 1, a reducing joint 2, a mud-water separation chamber 3, a rectangular window 3.1, a gas-water separation chamber 4, an annular inner boss 4.1, a gas detection chamber 5, an annular inner flange 5.1, an adapter 6, a compression gasket 7 and a sealing head 8; 1.1-connecting rod; 1.2-friction cylinder; 1.3-through holes; 1.4-pore water pressure sensor; 1.5-water permeable holes; 1.6-water permeable filter; 1.7-cone head; 1.8-a second deformed column; 1.9 strain gage; 1.10-friction of the internal steps of the barrel; 1.11 — first deformed column; 1.12-water-permeable blind holes; 9.1-air chamber, 9.2-sensor metal body, 9.3-pyroelectric detector, 9.4-printed circuit board, 9.5-sealing material, 9.6-epoxy resin board, 9.7-metal pin, 9.8-sensor metal plate, 9.9-air inlet hole and 9.10-MEMS infrared light source.

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

As shown in fig. 1, the device mainly comprises a mechanical property detection part of the seabed sediment, a shallow gas detection part and an ultrasonic wireless transmission part, wherein the mechanical property detection part of the seabed sediment is connected with an upper computer on the external sea surface through the ultrasonic wireless transmission part. The mechanical characteristic detection part of the submarine sediments realizes the measurement of mechanical parameters of the soil body pressure, the side wall friction force and the pore water pressure of the submarine sediments, the shallow layer gas detection part realizes the measurement of the concentration of the submarine shallow layer gas methane, and the ultrasonic wireless signal transmission part transmits the mechanical parameters of the submarine sediments to a signal receiving ultrasonic transducer in the gas detection chamber by a signal transmitting ultrasonic transducer in a way of crossing a mud-water separation chamber and the gas-water separation chamber; the methane concentration of shallow gas and the mechanical parameters of the seabed sediments are transmitted to an upper computer on a sea surface ship in a bus mode through a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit in a gas detection chamber.

According to the invention, the shallow gas is separated from the muddy water by the muddy water-gas separation structure of the shallow gas detection part, and then the methane concentration in the shallow gas is measured by the non-dispersive infrared methane sensor, so that the acquisition of the seabed shallow gas and the automatic real-time monitoring of the concentration are realized. The mechanical property detection part of the submarine sediments realizes the real-time measurement of three parameters of cone head resistance, side wall friction and pore water pressure representing the mechanical property of the submarine sediments through a strain sensitive element. The ultrasonic wireless data transmission part is mainly used for wirelessly transmitting data detected by the mechanical property detection part of the seabed sediments to the sensor placing chamber through a mud-water-gas separation structure of the ultrasonic transducer crossing the shallow gas detection part. And finally, transmitting the data measured by the two parts to an upper computer of the mother ship on the sea surface through a cable positioned in the sensor placing room.

The experiment result of the specific implementation shows that the method has the capability of comprehensively detecting the mechanical property of the submarine sediments and the shallow gas and has strong operability.

The mechanical property detection part of the seabed sediments and the shallow layer gas detection part form a comprehensive detection structure of the mechanical property and the shallow layer gas.

As shown in fig. 2, the comprehensive detection structure for mechanical properties and shallow gas comprises a multifunctional piezocone penetration test probe 1, a reducer union 2, a mud-water separation chamber 3, a gas-water separation chamber 4, a gas detection chamber 5, an adapter 6, a compression gasket 7 and a sealing head 8; the multifunctional piezocone penetration test device comprises a multifunctional piezocone penetration test probe 1, a mud-water separation chamber 3, a gas-water separation chamber 4, a gas detection chamber 5 and a sealing head 8 which are coaxially arranged from bottom to top in sequence, wherein a shallow gas detection part is mainly formed by the mud-water separation chamber 3, the gas-water separation chamber 4 and the gas detection chamber 5, and a mechanical property detection part of a submarine sediment is mainly formed by the multifunctional piezocone penetration test probe 1, a small signal amplification circuit and a single chip microcomputer;

the upper end of the multifunctional piezocone penetration test probe 1 is connected with the lower end of a mud-water separation chamber 3 into a whole through a reducing joint 2, the upper end of the mud-water separation chamber 3 is coaxially connected with the lower end of a gas-water separation chamber 4, the upper end of the gas-water separation chamber 4 is connected with the upper end of a gas detection chamber 5, the upper end of the gas detection chamber 5 is connected with a sealing head 8 through an adapter 6, and a compression gasket 7 is respectively arranged between the upper end and the lower end of the gas-water separation chamber 4 and the adapter 6.

Whole detection structure part all uses inside and outside threaded connection, has detachability, conveniently dismantles and detects the washing after accomplishing, and whole device is inside all hollow, as gas passage. The main parts of the structure will be described in detail below.

The mud-water-gas separation structure in the mud-water separation chamber 3, the gas-water separation chamber 4 and the gas detection chamber 5 is as follows:

as shown in fig. 3, the mud-water separation chamber 3 is cylindrical, a water-permeable ceramic pipe is placed inside the mud-water separation chamber, four rectangular windows 3.1 are formed in the coaxial outer wall of the water-permeable ceramic pipe and the multifunctional piezocone penetration probe 1, the rectangular windows 3.1 are uniformly distributed at intervals along the circumference, and porous ceramic or permeable stone is embedded in the rectangular windows 3.1 and can enable seawater rich in shallow gas to enter and isolate sediments; the lower external thread can be connected to the internal thread on the reducer union and connected with the reducer union; so as to be connected with the multifunctional piezocone penetration test probe.

As shown in fig. 4, the gas-water separation chamber 4 is cylindrical, an annular inner boss 4.1 is arranged on the inner wall of the middle part, a plurality of small holes are arranged on the annular inner boss 4.1, the small holes are used as gas flowing channels, permeable membranes are arranged on the annular inner boss 4.1, and pressing gaskets with the same small holes are used for pressing the permeable membranes; the upper end and the lower end are internal threads, two symmetrical semicircular grooves are formed in the inner wall, a circular groove is formed between the boss and the inner wall, and the circular groove is used for placing a circular ring-shaped sealing ring.

As shown in fig. 5, the gas detection chamber 5 is cylindrical, an annular inner flange 5.1 is arranged on the inner wall of the lower part, a waterproof breathable film is placed in a hole formed by the annular inner flange 5.1, and seawater does not enter the gas detection chamber due to the waterproof breathable film, so that the sensor and the detection circuit are not damaged; the upper end and the lower end are both internal threads, are respectively connected with the gas separation chamber and the sealing head through the adapter, are hollow and are used as a gas channel and a gas sensor.

The gas detection chamber 5 is internally provided with a non-dispersive infrared methane sensor, an ultrasonic signal receiving transducer, a non-dispersive infrared methane sensor, a shallow gas measurement and seabed sediment mechanical parameter transceiving circuit.

The collection of shallow layer gas is mainly completed by porous ceramic, permeable stone and waterproof and breathable film.

The porous ceramic/permeable stone has the functions of realizing mud-water separation and extracting the seawater rich in shallow gas from sediments. The porous ceramic/permeable stone is prepared by using corundum sand, silicon carbide and the like as main raw materials through a special sintering process, and has the advantages of high temperature resistance, high pressure resistance, acid, alkali and organic medium corrosion resistance, high aperture ratio and the like.