Wave velocity testing module, and device and method for simultaneously testing wave velocity and CPTU of soil body

Abstract

The invention discloses a wave velocity testing module, and a device and a method for simultaneously testing the wave velocity and CPTU of a soil body. The wave velocity testing module comprises a wave velocity testing module shell, a wave velocity measuring module and a wave velocity measuring module, the energy converter is used for converting the electric energy into sound energy and converting the sound energy into an electric signal at the same time; the adhesive layer is arranged in the space of the wave velocity testing module shell between the transducer and the reflecting plate; and the reflecting plate is arranged in the wave velocity testing module shell, is obliquely arranged above the energy converter, and is used for changing the sound wave emitted by the energy converter to be propagated in the direction perpendicular to the outer wall of the wave velocity testing module shell, receiving the reflected sound wave reflected by the soil body, changing the direction of the reflected sound wave and then transmitting the reflected sound wave to the energy converter. According to the device, CPTU testing and wave velocity testing can be completed at the same time in the one-time penetration process, multiple soil mass mechanical properties and acoustic parameters can be tested through one-time penetration of one set of equipment, the testing work efficiency is improved, and the testing result precision is more accurate.

Description

Technical Field

[0001] The invention relates to the technical field of wave velocity testing and static penetration testing devices, and in particular to a wave velocity testing module, and a device and method for simultaneously testing soil wave velocity and CPTU. Background Art

[0002] In recent years, my country's infrastructure construction has developed rapidly. Soil wave velocity test and CPTU test are important technical means in geotechnical engineering investigation. Among them, soil wave velocity test can evaluate site category, saturated silty sand liquefaction evaluation and geotechnical dynamic index calculation; At present, the wave velocity test methods in engineering investigation mainly include single hole method, cross hole method and surface wave method. The most commonly used wave velocity test is the in-hole wave velocity test, which requires drilling first, ground hammer hitting the city source, and the detector is received in the hole. The wave velocity is calculated by calculating the distance and time difference between transmission and reception. This method requires drilling first, mud in the hole, and manual hammer hitting as the source. The measurement cost is high, the work efficiency is not high, the collection interval is large, and there are problems with personnel fatigue. The quality of the results and work efficiency are low. The second is the single-hole PS logging technology. Although the electric pulse source is used to solve the problem of artificial excitation fatigue, PS logging has high requirements for the quality of the drilling, and the mud skin on the hole wall has a great impact on the quality of the test results.

[0003] CPTU testing is an important in-situ testing method for conducting site geological stratification, evaluation of rock and soil physical and mechanical parameters, calculation of foundation bearing capacity, pile foundation design, etc. In-situ testing technology has little disturbance to the soil, can maintain the original stress state of the soil, has high engineering efficiency, and has become the most widely used exploration technology. At present, the combination of CPTU testing and wave velocity testing technology is an important research direction. SCPTU technology has appeared in the industry. This SCPTU technology simply integrates the detector with the CPTU probe. The source is located on the ground and requires artificial or mechanical excitation. Each time it is excited, a wave velocity acquisition is completed. The current SCPTU technology separates the source and wave velocity test module, and uses artificial or mechanical excitation, which results in the inability of CPTU to penetrate continuously and low work efficiency; if the borehole is located in the water, the test will not be able to be carried out.

[0004] The problems existing in the existing SCPTU testing devices make it increasingly difficult to meet the needs of engineering investigations. Therefore, there is an urgent need for a set of efficient SCPTU in-situ testing devices and methods with reliable data quality. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the existing SCPTU testing device cannot be continuously penetrated when it is necessary to test the soil wave velocity, thereby providing a wave velocity testing module, a device and a method for simultaneously testing the soil wave velocity and CPTU, which can collect the soil wave velocity while collecting the cone tip resistance, side wall friction, pore water pressure and probe inclination during the continuous penetration process of the CPTU test module.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] Wave speed test module, including:

[0008] Wave speed test module housing;

[0009] A transducer, wherein the transducer is arranged inside the wave velocity test module housing, wherein the transducer is composed of a metal ring substrate and piezoelectric ceramic sheets are coupled on the inner and outer surfaces thereof respectively, and the transducer is used to convert electrical energy into acoustic energy and convert acoustic energy into electrical signals;

[0010] An adhesive layer, wherein the adhesive layer is disposed in a space of the wave velocity test module housing between the transducer and the reflector;

[0011] A reflector is arranged inside the shell of the wave velocity test module and tilted above the transducer. The reflector is used to change the sound waves emitted by the transducer to propagate perpendicularly to the direction of the outer wall of the shell of the wave velocity test module, receive the reflected sound waves reflected by the soil, and then change the direction of the reflected sound waves and transmit them to the transducer.

[0012] To further optimize the technical solution, the acoustic wave impedance of the adhesive layer is smaller than the acoustic wave impedance of the surrounding soil.

[0013] To further optimize the technical solution, a focusing plane is provided above the transducer, and the focusing plane is a hemispherical structure for gathering sound waves from different directions together to form a specific direction, which propagates to the surrounding medium or is received by the transducer.

[0014] To further optimize the technical solution, the reflector is made of a siliceous material, and the reflector can change the direction of the sound wave and propagate the soil reflected sound wave in a direction symmetrical to the incident angle.

[0015] To further optimize the technical solution, the angle between the reflector and the vertical direction is 45 degrees.

[0016] To further optimize the technical solution, a linear amplifier is also provided in the shell of the wave speed test module. The linear amplifier is electrically connected to the transducer. The linear amplifier is used to amplify the input signal and the received signal without distortion, thereby enhancing the signal and adjusting the gain and phase of the input signal.

[0017] To further optimize the technical solution, the linear amplifier has a built-in filter, and the filter is used to filter the input signal and the output signal.

[0018] To further optimize the technical solution, an interface is provided on the top of the wave speed test module shell, the interface is a connector, an oil circuit and a plurality of pins are provided on the interface, and the pins are connected to the data acquisition and control module through cables.

[0019] To further optimize the technical solution, the interface includes a male interface and a female interface, a notch is provided between two adjacent pins of the female interface, and a protrusion adapted to the notch is provided at the corresponding positions of the male interface and the female interface.

[0020] To further optimize the technical solution, a waterproof shell is provided on the outside of the interface, and silicone oil is filled in the waterproof shell.

[0021] The device for testing soil wave velocity and CPTU at the same time comprises a CPTU test module, a connection circuit module and the wave velocity test module which are connected in sequence from bottom to top, wherein the CPTU test module, the connection circuit module and the wave velocity test module are connected to a data acquisition and control module; the wave velocity test module is used to convert electrical energy into sound energy and emit it to the soil, and receive the sound waves reflected at the contact surface between the wave velocity test module shell and the soil and convert them into electrical signals and transmit them to the data acquisition and control module, and the data acquisition and control module is used to calculate the soil wave velocity based on the medium reflectivity calculation formula.

[0022] The test method for simultaneously testing soil wave velocity and CPTU includes the following steps:

[0023] S1. The device for simultaneously testing soil wave velocity and CPTU is continuously penetrated into the soil, and data is collected through the CPTU test module during the penetration process;

[0024] S2. While the test device continues to penetrate the soil, the wave velocity test module is started, the wave velocity test module continuously emits sound waves to the soil, and receives the sound wave reflection signal, the wave velocity test module sound wave reflection signal;

[0025] S3. Continue to penetrate the test device and repeat steps S1-S2 until the experiment is completed and the test device is recovered;

[0026] S4. Calculate the soil wave velocity based on the medium reflectivity calculation formula through the data acquisition and control module.

[0027] To further optimize the technical solution, step S4 specifically includes the following steps:

[0028] According to the test results of the CPTU test module, the density of the soil ρ is calculated by combining the saturated density calculation formula. 2 ; The reflectivity R is calculated by the ratio of the received reflected sound wave signal intensity to the transmitted sound wave signal intensity; the density of the adhesive layer ρ is known 1 and the wave velocity V of the adhesive layer 1 , according to the calculation formula of the reflectivity of the two media: R = r 2 ×v 2 -r 1 ×v 1

[0029] ρ 2 ×v 2 +ρ 1 ×v 1 Calculate the soil wave velocity V 2 .

[0030] The technical solution of the present invention has the following advantages:

[0031] 1. A wave velocity test module provided by the present invention utilizes a transducer to convert electrical energy into sound energy, so that the wave velocity test module can both transmit and receive sound waves. After the wave velocity test module is coupled and installed with the CPTU test module, no additional artificial or mechanical excitation of the seismic source located on the ground is required, and the sound wave can be directly transmitted and received by the transducer itself, so that the CPTU test module and the wave velocity test module can continuously penetrate the soil, greatly improving the work efficiency.

[0032] 2. The present invention provides a wave velocity testing module, in which the adhesive layer can firmly fix the focusing surface and the reflecting plate, and can maintain good bonding performance under high temperature and high pressure, and the density is small, the shear wave velocity is less than 70m / s, and the acoustic wave impedance of the adhesive layer is less than the acoustic wave impedance of the surrounding soil. When the acoustic wave is transmitted, an acoustic wave reflection interface is formed at the contact surface between the outer wall of the wave velocity testing module shell and the soil.

[0033] 3. The present invention provides a wave velocity testing module, in which the focusing surface can ensure that the sound waves emitted by the transducer are focused on the reflecting plate to a greater extent, and can receive the sound waves reflected by the soil to a greater extent, thereby reducing energy waste and making the measurement of soil wave velocity more accurate.

[0034] 4. In a wave velocity test module provided by the present invention, the angle between the reflector and the vertical direction is 45 degrees, which solves the problem of miniaturization of the structure when the outer wall diameter is fixed and the internal space is limited.

[0035] 5. The present invention provides a wave velocity test module, the interface includes an interface male head and an interface female head, a semi-cylindrical notch is provided between two adjacent pins of the interface female head, and a semi-cylindrical protrusion matching the notch is provided at the corresponding position of the interface male head and the interface female head to prevent mis-insertion. A metal waterproof shell is provided outside the interface, and silicone oil is filled in the metal waterproof shell to prevent water from penetrating into the soil and causing poor contact.

[0036] 6. The present invention provides a testing device for testing soil wave velocity and CPTU at the same time, which can achieve simultaneous measurement of in-situ soil wave velocity, cone tip resistance, side wall friction, pore water pressure, probe inclination and other parameters, and obtain continuous soil test results, with high test operation efficiency. The present invention can complete CPTU test and wave velocity test at the same time during one penetration process, and realize that a set of equipment can test multiple soil mechanical properties and acoustic parameters in one penetration, which not only improves the test work efficiency, but also makes the test result more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the overall structure of a testing device for simultaneously testing soil wave velocity and CPTU provided by the present invention.

[0039] Figure 2 The overall structural cross-sectional view of the testing device for simultaneously testing soil wave velocity and CPTU provided by the present invention.

[0040] Figure 3 This is a structural diagram of the wave speed test module provided by the present invention.

[0041] Figure 4 A schematic diagram of the wave velocity testing module provided by the present invention when performing sound wave reflection.

[0042] Figure 5 This is a schematic diagram of the interface on the wave speed test module provided by the present invention.

[0043] Figure 6 A schematic diagram of the structure of a testing device for simultaneously testing soil wave velocity and CPTU provided by the present invention.

[0044] Reference numerals:

[0045] 1. CPTU test module, 101. probe, 102. pore pressure sensor, 103. permeable stone, 104. hollow top column, 105. temperature sensor, 106. side wall friction cylinder, 107. strain gauge, 108. joint;

[0046] 2. Connecting circuit module, 201, connecting tube, 202, charge amplifier, 203, circuit board;

[0047] 3. Wave velocity test module, 301. Transducer, 302. Focusing surface, 303. Adhesive layer, 304. Reflection plate, 305. Linear amplifier, 306. Interface;

[0048] 4. Cables;

[0049] 5. Data acquisition and control module;

[0050] 6. Power supply;

[0051] 7. Soil. DETAILED DESCRIPTION

[0052] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the present invention uses a transducer to convert electrical energy into acoustic energy to illustrate the wave velocity test module of the present invention is only a preferred embodiment, and does not limit the protection scope of the wave velocity test module.

[0053] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "an" as used herein may also be meant to include the plural forms. The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0054] Although the terms first, second, etc. may be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. In addition, in the description of the present invention, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0055] For ease of description, spatial relative terms can be used in the text to describe the relationship of an element or feature relative to another element or feature as shown in the figure, and these relative terms are, for example, "front", "rear", "middle", "inside", "longitudinal", "lateral", "side", "vertical", "outside", etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation in addition to the orientation depicted in the figure. For example, if the mechanism in the figure flips, the element described as "below other elements or features" or "below other elements or features" will be subsequently oriented to "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include the orientation on and below. The mechanism can be oriented in addition (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0056] In recent years, my country's infrastructure construction has developed rapidly. Soil wave velocity test and CPTU test are important technical means in geotechnical engineering investigation. Among them, soil wave velocity test can evaluate site category, saturated silty sand liquefaction evaluation and geotechnical dynamic index calculation; At present, the wave velocity test methods in engineering investigation mainly include single hole method, cross hole method and surface wave method. The most commonly used wave velocity test is the in-hole wave velocity test, which requires drilling first, ground hammer hitting the city source, and the detector is received in the hole. The wave velocity is calculated by calculating the distance and time difference between transmission and reception. This method requires drilling first, mud in the hole, and manual hammer hitting as the source. The measurement cost is high, the work efficiency is not high, the collection interval is large, and there are problems with personnel fatigue. The quality of the results and work efficiency are low. The second is the single-hole PS logging technology. Although the electric pulse source is used to solve the problem of artificial excitation fatigue, PS logging has high requirements for the quality of the drilling, and the mud skin on the hole wall has a great impact on the quality of the test results.

[0057] CPTU testing is an important in-situ testing method for conducting site geological stratification, evaluation of rock and soil physical and mechanical parameters, calculation of foundation bearing capacity, pile foundation design, etc. In-situ testing technology has little disturbance to the soil, can maintain the original stress state of the soil, has high engineering efficiency, and has become the most widely used exploration technology. At present, the combination of CPTU testing and wave velocity testing technology is an important research direction. SCPTU technology has appeared in the industry. This SCPTU technology simply integrates the detector with the CPTU probe. The source is located on the ground and requires artificial or mechanical excitation. Each time it is excited, a wave velocity acquisition is completed. The current SCPTU technology separates the source and wave velocity test module, and uses artificial or mechanical excitation, which results in the inability of CPTU to penetrate continuously and low work efficiency; if the borehole is located in the water, the test will not be able to be carried out.

[0058] The problems existing in the existing SCPTU test device make it increasingly difficult to meet the needs of engineering investigation. Therefore, there is an urgent need for a set of efficient SCPTU in-situ test devices and methods with reliable data quality. The transducer is used to convert electrical energy into acoustic energy, so that the wave velocity test module can emit and receive sound waves by itself after being installed on the CPTU test module, thereby realizing the simultaneous testing of soil wave velocity and CPTU.

[0059] Example 1

[0060] The specific embodiments of the present invention are described in detail below in conjunction with the wave speed test module of the first aspect of the present invention.

[0061] It should be noted that the wave speed test module of the first aspect of the present invention is only a preferred embodiment of the present invention. The wave speed test module of the present invention can adopt the wave speed test module of the first aspect of the present invention or other structures. For the convenience of explanation, the wave speed test module of the first aspect of the present invention is used for explanation below.

[0062] like Figures 2 to 4 As shown, this embodiment discloses a wave velocity testing module, including a wave velocity testing module housing, a transducer 301 , an adhesive layer 303 and a reflective plate 304 .

[0063] Among them, the shell of the wave speed test module is set to be a hollow cylinder.

[0064] The transducer 301 is arranged inside the shell of the wave velocity test module. The transducer 301 is a hollow cylindrical structure. The transducer 301 is made of a metal ring substrate with piezoelectric ceramic sheets coupled (bonded) on its inner and outer surfaces respectively. The transducer 301 is used to convert electrical energy into sound energy and convert sound energy into electrical signals.

[0065] The adhesive layer 303 is disposed in the space of the wave velocity test module housing between the transducer 301 and the reflector 304 , and the adhesive layer 303 serves to fix the reflector 304 .

[0066] The reflector 304 is arranged inside the shell of the wave velocity test module and is tilted above the transducer 301. The reflector 304 is used to change the sound waves emitted by the transducer 301 to propagate perpendicularly to the direction of the outer wall of the shell of the wave velocity test module, and receive the reflected sound waves reflected by the soil and then change the direction of the reflected sound waves and transmit them to the transducer 301.

[0067] The above-mentioned wave velocity test module utilizes the transducer 301 to convert electrical energy into sound energy, so that the wave velocity test module can both transmit and receive sound waves. After the wave velocity test module is coupled and installed with the CPTU test module, no additional artificial or mechanical excitation of the seismic source located on the ground is required, and the transducer 301 itself can be directly used to realize the transmission and reception of sound waves, thereby enabling the CPTU test module and the wave velocity test module to continuously penetrate the soil, greatly improving work efficiency.

[0068] In some embodiments, the adhesive layer 303 is a special material with an adhesive effect. It can firmly fix the focusing plane 302 and the reflective plate 304, and can maintain good adhesive properties under high temperature and high pressure. The density is small, the shear wave velocity is less than 70m / s, and the acoustic impedance of the adhesive layer is less than the acoustic impedance of the surrounding soil. When the acoustic wave is transmitted, an acoustic wave reflection interface is formed at the contact surface between the outer wall of the wave velocity test module shell and the soil 7.

[0069] In some embodiments, a focusing plane 302 is provided above the transducer 301. The focusing plane 302 is a hemispherical structure, which is used to gather sound waves of different directions together to form a specific direction, propagate to the surrounding medium or be received by the transducer. More specifically, the sound wave is reflected at the contact surface between the outer wall of the wave velocity test module shell and the soil 7, and the reflected wave is focused by the focusing plane 302 again and received by the transducer 301. In this embodiment, the setting of the focusing plane 302 can ensure that the sound waves emitted by the transducer 301 are focused on the reflector 304 to a greater extent, and can receive the reflected sound waves of the soil to a greater extent, reduce energy waste, and make the measurement of soil wave velocity more accurate.

[0070] In some embodiments, the reflector 304 is made of a siliceous material, has an elliptical structure, and has a smooth surface. It is capable of changing the direction of sound waves and transmitting the soil reflected sound waves in a direction symmetrical to the incident angle.

[0071] Furthermore, the reflection plate 304 has an angle of 45 degrees with the vertical direction, which can change the direction of the sound wave excited by the transducer 301 and propagate in a direction perpendicular to the outer wall of the instrument; the outer wall of the wave velocity test module shell is reflected from the contact surface with the soil 7, and the reflected wave is changed in direction by the reflection plate 304 again, propagates in the vertical direction, and is received by the focusing surface 302, and the sound wave signal is converted into an electrical signal through the transducer 301.

[0072] In some embodiments, a linear amplifier 305 is further provided in the shell of the wave velocity testing module. The linear amplifier 305 is a rectangular structure. The linear amplifier 305 is electrically connected to the transducer 301. The linear amplifier 305 is used to amplify the input signal and the received signal without distortion to enhance the signal, and at the same time adjust the gain and phase of the input signal to a certain extent.

[0073] The linear amplifier 305 has a built-in filter, and the filter is used to filter the input signal and the output signal to achieve the effect of removing noise.

[0074] In some embodiments, an interface 306 is provided above the wave velocity test module housing. Figure 5 As shown, the interface 306 is a circular IEC standard connector, which is provided with 18 pins and 1 oil circuit. The oil circuit is located in the center, and the 18 pins are evenly arranged in a ring shape with the oil circuit as the center, providing power, signal transmission and hydraulic oil transmission for instruments and equipment.

[0075] The interface 306 includes a male interface and a female interface. A semi-cylindrical notch is provided between two adjacent pins of the female interface. A semi-cylindrical protrusion matching the notch is provided at the corresponding positions of the male interface and the female interface to prevent mis-insertion.

[0076] The interface 306 is provided with a metal waterproof shell on the outside, and the metal waterproof shell is filled with silicone oil to prevent water from seeping into the soil and causing poor contact.

[0077] Example 2

[0078] The specific embodiments of the present invention are described in detail below in conjunction with the testing device for simultaneously testing soil wave velocity and CPTU according to the second aspect of the present invention.

[0079] It should be noted that the test device for simultaneously testing soil wave velocity and CPTU of the second aspect of the present invention is only a preferred embodiment of the present invention. The test device for simultaneously testing soil wave velocity and CPTU of the present invention can adopt the test device for simultaneously testing soil wave velocity and CPTU of the second aspect of the present invention, and can also adopt other structures. For the convenience of explanation, the test device for simultaneously testing soil wave velocity and CPTU of the second aspect of the present invention is explained below.

[0080] like Figures 1 to 6As shown, this embodiment discloses a test device for simultaneously testing soil wave velocity and CPTU, which is used to continuously obtain soil wave velocity, cone tip resistance, side wall friction, pore water pressure and probe inclination in one test, including a CPTU test module 1, a connection circuit module 2 and a wave velocity test module 3 connected in sequence from bottom to top, the CPTU test module 1, the connection circuit module 2 and the wave velocity test module 3 are connected to a data acquisition and control module 5, and the data acquisition and control module 5 is also connected to a power supply 6, which is used to power the entire device.

[0081] The wave velocity testing module 3 is used to convert electrical energy into sound energy and emit it to the soil, and receive the sound waves reflected at the contact surface between the wave velocity testing module shell and the soil 7 and convert them into electrical signals and transmit them to the data acquisition and control module 5. The data acquisition and control module 5 is used to calculate the soil wave velocity based on the medium reflectivity calculation formula.

[0082] In this embodiment, the CPTU test module 1 is first penetrated into the soil. During the penetration process, the data acquisition and control module 5 tests and controls the CPTU test module 1 and the soil wave velocity test module 3. The pressure, side resistance, and pore water pressure sensor signals are converted into electrical signals through the connecting circuit module 2, and transmitted to the data acquisition and control module 5 by 18 wires and 1 oil circuit composite cable 4, so as to obtain the side resistance, end resistance, pore water pressure, and probe inclination parameters, store the data, and display related graphics.

[0083] CPTU test module 1 is a static penetration module, which is installed at the bottom and mainly consists of a probe 101, a pore pressure sensor 102, a permeable stone 103, a hollow top column 104, a temperature sensor 105, a side wall friction cylinder 106, a strain gauge 107, and a joint 108. The probe 101 is installed at the bottom of the CPTU test module 1, and the top of the probe 101 is connected to the hollow top column 104. The pore pressure sensor 102 and the permeable stone 103 are installed inside the hollow top column 104 and connected to the outside through a small hole. The side wall friction cylinder 106 is installed outside the hollow top column 104, and the side wall friction strain gauge 107 is installed inside the side wall friction cylinder 106. The cone tip resistance of the probe 101 is transmitted to the hollow top column 104 and tested, the pore water pressure is transmitted to the pore pressure sensor 102 through the permeable stone 103 and tested, and the side wall friction is transmitted to the strain gauge 107 through the side wall friction cylinder 106 and tested. The cone tip resistance, side wall friction and pore water pressure tested by the CPTU test module 1 are output as digital signals after AD conversion.

[0084] The connecting circuit module 2 includes a connecting tube 201 , a charge amplifier 202 , and a circuit board 203 . The connecting tube 201 is connected to the connector 108 , and the charge amplifier 202 and the circuit board 203 are built in the connecting tube 201 .

[0085] When testing the above-mentioned test device for simultaneously testing the wave velocity and CPTU of the soil, the probe is penetrated into the soil to a predetermined depth by penetration, and the transducer converts the electrical energy into acoustic energy, which excites the generation of shear waves. The propagation direction of the shear waves is changed by the reflector, and the shear waves are reflected at the interface between the adhesive layer and the soil. The reflected shear waves are changed in direction again by the reflective surface and received by the transducer. The data acquisition and control module performs data acquisition and completes the storage, and at the same time displays the graphics of the excitation pulse signal and the received signal on the computer screen, and calculates the reflectivity R. In the process of the CPTU test module penetrating the soil, the lateral resistance, end resistance and pore water pressure of the soil are obtained at the same time, displayed on the computer screen in a timely manner, and the soil density is calculated. The present invention can simultaneously complete the CPTU test and the wave velocity test in one penetration process, and realize that a set of equipment can test a variety of soil mechanical properties and acoustic parameters in one penetration, which not only improves the work efficiency of the test, but also makes the test result more accurate.

[0086] Example 3

[0087] The specific embodiments of the present invention are described in detail below in conjunction with the test method for simultaneously testing soil wave velocity and CPTU according to the third aspect of the present invention.

[0088] It should be noted that the test method for simultaneously testing soil wave velocity and CPTU of the third aspect of the present invention is only a preferred embodiment of the present invention. The test method for simultaneously testing soil wave velocity and CPTU of the present invention can be carried out by using the test method for simultaneously testing soil wave velocity and CPTU of the third aspect of the present invention, or by using other methods. For the convenience of explanation, the test method for simultaneously testing soil wave velocity and CPTU of the third aspect of the present invention is explained below.

[0089] This embodiment discloses a test method for simultaneously testing soil wave velocity and CPTU, comprising the following steps:

[0090] S1. The device for testing soil wave velocity and CPTU simultaneously is continuously penetrated into the soil. During the penetration process, the CPTU test module 1 is used to collect data, including cone tip resistance, side wall friction, pore water pressure and probe inclination.

[0091] S2. While the test device continues to penetrate the soil, the wave velocity test module 3 is started, and the wave velocity test module 3 continuously emits sound waves to the soil and receives sound wave reflection signals. The wave velocity test module 3 collects wave velocity data in a timely manner and displays the waveform signal on the collection software.

[0092] S3. Continue to penetrate the test device and repeat steps S1-S2 until the experiment is completed, and then recycle the test device.

[0093] S4. Calculate the soil wave velocity based on the medium reflectivity calculation formula through the data acquisition and control module 5.

[0094] According to the test results of CPTU test module 1, combined with the saturation density calculation formula ρ 2 =1.771×q t 0.066 g / cm 3 , when q t ≥30MPa,ρ 2 =2.2g / cm 3 ; Calculate the density of the soil ρ 2 ; The ratio of the received reflected sound wave signal intensity to the transmitted sound wave signal intensity is the reflectivity R; the density of the adhesive layer ρ is known 1 and wave speed V 1 , according to the calculation formula of the reflectivity of the two media: Calculate the soil wave velocity V 2 In this step, the CPTU test module 1 is coupled with the wave velocity test module 3, and the soil density is calculated using the CPTU test module 1. Then, the soil wave velocity is calculated using the density of the soil, the density of the adhesive layer, the wave velocity of the adhesive layer, and the ratio of the reflected sound wave signal intensity to the transmitted sound wave signal intensity, i.e., the reflectivity.

[0095] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. Wave speed test module, characterized in that: include: Wave speed test module housing; A transducer (301), the transducer (301) being arranged inside a shell of the wave velocity test module, the transducer (301) being capable of converting electrical energy into acoustic energy, and simultaneously capable of converting acoustic energy into electrical signals; An adhesive layer (303), the adhesive layer (303) being arranged in a space of a housing of the wave velocity testing module between the transducer (301) and the reflection plate (304); A reflecting plate (304), wherein the reflecting plate (304) is arranged inside the shell of the wave velocity test module and is arranged obliquely above the transducer (301), and the reflecting plate (304) is used to change the sound waves emitted by the transducer (301) to propagate in a direction perpendicular to the outer wall of the shell of the wave velocity test module, and to receive the reflected sound waves reflected by the soil and then change the direction of the reflected sound waves and transmit them to the transducer (301).

2. The wave speed test module according to claim 1, characterized in that: The acoustic wave impedance of the adhesive layer (303) is smaller than the acoustic wave impedance of the surrounding soil.

3. The wave speed test module according to claim 1, characterized in that: A focusing surface (302) is arranged above the transducer (301), and the focusing surface (302) is a hemispherical structure, and is used to gather sound waves in different directions together to form a specific direction, which is propagated to the surrounding medium or received by the transducer.

4. The wave speed test module according to claim 3, characterized in that: The reflector (304) is made of a siliceous material and is capable of changing the direction of sound waves and propagating the soil reflected sound waves in a direction symmetrical to the incident angle.

5. The wave speed test module according to claim 3, characterized in that: The angle between the reflector (304) and the vertical direction is 45 degrees.

6. The wave velocity test module according to claim 3, characterized in that: A linear amplifier (305) is also provided in the shell of the wave velocity test module. The linear amplifier (305) is electrically connected to the transducer (301). The linear amplifier (305) is used to amplify the input signal and the received signal without distortion, thereby enhancing the signal and adjusting the gain and phase of the input signal.

7. The wave speed test module according to claim 6, characterized in that: The linear amplifier (305) has a built-in filter, and the filter is used to perform filtering processing on input signals and output signals.

8. The wave speed test module according to claim 1, characterized in that: An interface (306) is provided above the shell of the wave velocity test module. The interface (306) is a connector. An oil circuit and a plurality of pins are provided on the interface (306). The pins are connected to the data acquisition and control module (5) via a cable (4).

9. The wave speed test module according to claim 8, characterized in that: The interface (306) comprises an interface male head and an interface female head, a notch is provided between two adjacent pins of the interface female head, and a protrusion matching the notch is provided at positions corresponding to the interface male head and the interface female head.

10. The wave speed test module according to claim 8, characterized in that: The interface (306) is provided with a waterproof shell outside, and the waterproof shell is filled with silicone oil.

11. A device for simultaneously testing soil wave velocity and CPTU, characterized in that: The invention comprises a CPTU test module (1), a connection circuit module (2) and a wave velocity test module (3) as described in any one of claims 1 to 10, which are connected in sequence from bottom to top. The CPTU test module (1), the connection circuit module (2) and the wave velocity test module (3) are connected to a data acquisition and control module (5); the wave velocity test module (3) is used to convert electrical energy into sound energy and emit it to the soil, and receive the sound waves reflected at the contact surface between the wave velocity test module shell and the soil (7) and convert them into electrical signals and transmit them to the data acquisition and control module (5); the data acquisition and control module (5) is used to calculate the soil wave velocity based on the medium reflectivity calculation formula.

12. A method for simultaneously testing soil wave velocity and CPTU, characterized in that: The method is based on the device for simultaneously testing soil wave velocity and CPTU according to claim 11, and comprises the following steps: S1. The device for simultaneously testing soil wave velocity and CPTU is continuously penetrated into the soil, and data is collected through the CPTU test module (1) during the penetration process; S2. While the test device continues to penetrate the soil, the wave velocity test module (3) is started, and the wave velocity test module (3) continuously emits sound waves to the soil and receives the sound wave reflection signal, the wave velocity test module (3) sound wave reflection signal; S3. Continue to penetrate the test device and repeat steps S1-S2 until the experiment is completed and the test device is recovered; S4. Calculate the soil wave velocity based on the medium reflectivity calculation formula through the data acquisition and control module (5).

13. The method for simultaneously testing soil wave velocity and CPTU according to claim 12, characterized in that: Step S4 specifically includes the following steps: According to the test results of the CPTU test module (1), the density of the soil ρ2 is calculated by combining the saturated density calculation formula; the reflectivity R is calculated by the ratio of the received reflected sound wave signal intensity to the transmitted sound wave signal intensity; the density ρ1 of the adhesive layer and the wave velocity V1 of the adhesive layer are known, and the reflectivity of the two media is calculated by the calculation formula of the reflectivity of the two media. R＝ ρ2×v2-ρ1×v1 The soil wave velocity V2 is calculated using the calculation formula: ρ2×v2+ρ1×v1.

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