A Fin-Type Automatic Extended Seismic Wave Hole Pressure Static Penetration Testing System and Method

Abstract

This invention relates to a fin-type automatic extended seismic wave pore pressure static cone penetration test system and method. The test system includes: a rear end cylinder and a side wall sleeve connected sequentially from top to bottom and internally connected; a conical probe connected to the lower end of the side wall sleeve; a pore pressure sensor disposed at the connection point between the side wall sleeve and the conical probe; a seismic wave exciter and a seismic wave receiver mounted from top to bottom on the side wall of the rear end cylinder and capable of fin-like expansion or contraction; a signal controller and a signal processor installed inside the rear end cylinder, the signal controller being connected to the seismic wave exciter and the signal processor being connected to the seismic wave receiver; and a computer connected to the signal controller and the signal processor via coaxial cables. This invention can acquire in-situ seismic wave data, featuring high efficiency, speed, and simple operation, providing a more convenient testing tool for acquiring in-situ seismic wave data.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering testing technology, and relates to a fin-type automatic extended seismic wave borehole pressure static cone penetration test system and method. Background Technology

[0002] Seismic waves are vibrations generated when energy is released from the Earth's interior. They propagate throughout the Earth's interior and on its surface, providing crucial information about the Earth's internal structure. When seismic waves pass through different media, factors such as the medium's density, elasticity, water content, and structure influence the wave's velocity, direction, and intensity. Based on these wave propagation characteristics, interpretation can reveal the physical and mechanical properties of the medium, enabling purposes such as stratigraphic and lithological identification, foundation and bearing capacity assessment, and seismic hazard assessment. Therefore, seismic wave pore pressure static cone penetration testing is widely used in geotechnical engineering.

[0003] In conventional seismic wave borehole pressure static penetration tests, the seismic wave excitation device is often separate from the penetration device and placed on the ground, using a hammer to strike an iron block to generate seismic waves. When the penetration depth is deep, due to the limited excitation kinetic energy, the wave energy often cannot be effectively transmitted to the receiver of the penetration device, leading to inaccurate measurement data.

[0004] For example, Chinese patent CN106759215B discloses a multifunctional digital seismic wave pore pressure static cone penetration test system, including a conical head (1), a pore pressure filter ring (2), a sidewall friction cylinder (3), an adapter (4), an adapter rod (5), a friction-reducing rod (6), a probe rod (7), a host computer data acquisition circuit board (8), a depth encoder (9), a data acquisition computer (10), and a coaxial cable (11). The coaxial cable (11) passes through the friction-reducing rod (6) and the probe rod (7), with one end connected to two power lines and two signal lines in the adapter rod (5), and the other end connected to the host computer data acquisition circuit board (8). This patent transmits seismic waves by hammering an iron block, and the energy is greatly attenuated during transmission, which increases the difficulty and reduces the accuracy of data acquisition in deep soil layers. Moreover, this seismic wave acquisition relies on the excitation method of manual hammering, which means that the acquired data may be affected by the operator's skill and force, resulting in poor repeatability and consistency, which may affect the consistency of the data. While percussion-induced shear wave generation is a common technique, its effective transmission distance is limited, typically covering only 10-20 meters below the ground. For deeper soil layers, the rapid attenuation of wave energy, coupled with the influence of complex geological conditions (such as permafrost and karst) on wave propagation characteristics, significantly reduces the accuracy and reliability of test results. Furthermore, noise interference in terrestrial environments is a significant factor, potentially masking or distorting seismic wave signals and further reducing test precision. When SCPTU technology is applied to aquatic environments, the challenges are even more severe. In aquatic environments, especially deep water or complex seabed topography, traditional methods of generating shear waves on the ground are almost infeasible. Due to the presence of water layers, shear waves generated by percussion cannot effectively propagate to the soil beneath the riverbed or seabed, and it is impossible to ensure that the shear waves can penetrate the water and reach the probe sensor installed in deep soil. This directly leads to a gap in the combined testing of shear wave velocity and static cone penetration in aquatic environments, limiting the application and development of SCPTU technology in these critical areas.

[0005] Therefore, to meet the exploration needs under complex geological conditions in deep land and water, there is an urgent need to develop a novel static cone penetration test system that integrates seismic wave excitation and reception functions. This system should be able to generate and receive seismic wave signals directly at the probe location without relying on an external excitation source. This would overcome the limitations of traditional methods in water and deep soil conditions, improve the accuracy, reliability, and repeatability of test data, and provide more comprehensive and in-depth geological information support for geotechnical engineering, marine engineering, and other fields. Summary of the Invention

[0006] The purpose of this invention is to provide a finned automatic extended seismic wave borehole pressure static penetration test system and method to solve the problems of separation between the excitation device and the penetration device in conventional seismic wave borehole pressure static penetration test devices. It can excite seismic waves through self-excitation, providing a more efficient and convenient method for seismic wave detection in geotechnical engineering investigation.

[0007] To overcome the predicament that the mechanical waves emitted by the seismic wave exciter carried by the probe propagate along the relatively stiff probe rather than along the soil during the static cone penetration test, this invention proposes a fin-type automatic extension seismic wave testing system based on the biomimetic principle of fish fins that can extend and retract. This system enables the seismic wave testing unit to automatically retract during the probe penetration drilling process for self-protection. When testing is required, it automatically extends by pulling out the external probe and decouples from the probe to conduct self-excited wave velocity testing.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] In one aspect, the present invention provides a finned automatic extended seismic wave borehole pressure static cone penetration test system, comprising:

[0010] The rear end sleeve and the side wall sleeve are connected sequentially from top to bottom and are internally connected;

[0011] The conical probe is connected to the lower end of the sidewall sleeve;

[0012] A bore pressure sensor is installed at the connection between the sidewall sleeve and the conical probe;

[0013] A seismic wave exciter and a seismic wave receiver, which are installed from top to bottom on the side wall of the rear cylinder and can be deployed or retracted in a fin-like manner;

[0014] A signal controller and a signal processor are installed inside the rear end cylinder. The signal controller is connected to the seismic wave exciter, and the signal processor is connected to the seismic wave receiver.

[0015] And a computer that connects the signal controller and the signal processor via coaxial cables.

[0016] Furthermore, an exciter mounting bracket and a receiver mounting bracket are hinged to the side wall of the rear cylinder, and the seismic wave exciter and the seismic wave receiver are respectively mounted on the exciter mounting bracket and the receiver mounting bracket.

[0017] Furthermore, the exciter mounting bracket and the receiver mounting bracket are each mounted on the rear end cylinder sidewall via a hinge point, and the hinge point can be opened and closed by signal control. Specifically, the rotation range of the exciter mounting bracket and the receiver mounting bracket can be 0 to 30°, where 0° is defined as the position where the mounting bracket is closest to the rear end cylinder sidewall.

[0018] Furthermore, the position of the hinge point satisfies the condition that it does not extend beyond the outer surface of the rear end cylinder sidewall.

[0019] Furthermore, the shapes of the exciter holder and receiver holder satisfy the following condition: when the upper part of the exciter holder and receiver holder approaches the rear end cylinder to its maximum extent, there is still a gap between the upper part of the exciter holder and receiver holder and the outer surface of the side wall of the rear end cylinder, so as to prevent physical interference between the components.

[0020] Furthermore, the exciter mounting bracket and the receiver mounting bracket are respectively equipped with an exciter displacement switch and a receiver displacement switch. The signal controller is connected to the seismic wave exciter through the exciter displacement switch, and the signal processor is connected to the seismic wave receiver through the receiver displacement switch.

[0021] Furthermore, the outer surfaces of the seismic wave exciter and the seismic wave receiver are respectively provided with a silicone rubber coating for the exciter and a silicone rubber coating for the receiver.

[0022] Furthermore, the distance between the seismic wave exciter and the seismic wave receiver is 250-350 mm, so that the seismic waves have a certain transmission path, thereby obtaining relevant soil layer data.

[0023] Furthermore, the upper end of the conical probe is also provided with a pore pressure filter ring.

[0024] Furthermore, the upper end of the rear end cylinder is also connected to a threaded connector for connecting to an external probe.

[0025] Furthermore, the cone angle of the conical probe is 60°, and the cross-sectional area of ​​the cone base is 10–15 cm². 2 Preferably 10 or 15 cm 2 .

[0026] Furthermore, the height of the rear end sleeve is 600-1000mm, and the cross-sectional area of ​​the lower end face of the rear end sleeve is equal to the cross-sectional area of ​​the side wall sleeve.

[0027] Furthermore, the surface area of ​​the sidewall sleeve is 100–300 cm². 2 The cross-sectional area is equal to the cross-sectional area of ​​the cone base of the conical probe.

[0028] Furthermore, the thickness of the pore pressure filter ring is 2-8 mm.

[0029] Furthermore, the exciter displacement switch is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm.

[0030] Furthermore, the receiver displacement switch is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm.

[0031] Furthermore, the length of the seismic wave exciter is 100–200 mm.

[0032] Furthermore, the length of the seismic wave receiver is 100–200 mm.

[0033] Furthermore, the signal controller includes a signal generator, a modulation module, and an output interface.

[0034] Furthermore, the signal processor includes a receiving module, a tuner, a demodulator, an amplifier, and an output module.

[0035] On the other hand, the present invention provides a finned automatic extended seismic wave hole pressure static cone penetration test method, which is based on the finned automatic extended seismic wave hole pressure static cone penetration test system as described above, and the test method includes the following steps:

[0036] (1) Perform static penetration test on the predetermined test point using conventional penetration method, and control its penetration rate to be constant. At this time, the seismic wave exciter and the seismic wave receiver are in a retracted state.

[0037] (2) When conducting seismic wave testing, pause the penetration operation and raise the rear end cylinder at a constant rate so that the seismic wave exciter and seismic wave receiver can be finned and deflected laterally until the set angle is reached.

[0038] (3) The computer sends an electrical signal to the signal controller and transmits it to the seismic wave exciter, causing it to generate seismic waves in the soil and transmit them downwards until they are captured by the seismic wave receiver below.

[0039] (4) After the seismic wave receiver detects the signal, it is transmitted to the signal processor and then output to the computer. After processing, the speed and characteristics of the seismic wave propagating in the underground medium are extracted.

[0040] When the testing system of this invention is in operation, after reaching the target depth, the computer sends a signal via a coaxial cable to activate the displacement switch of the exciter and receiver, causing the hinge point of the fixed exciter and receiver brackets to open. During the lifting of the probe, the fin-shaped seismic wave exciter and receiver unfold laterally. When the deflection angle reaches a preset limit of 30°, the signal controller sends a signal to control the seismic wave exciter to generate seismic waves, which are then received by the seismic wave receiver. Simultaneously, the seismic wave exciter and receiver need to deflect before emitting seismic waves primarily to generate clearer seismic waveforms. After unfolding, the seismic waves generated by the exciter can propagate more directly to the receiver, unaffected by the probe's own damping or interference.

[0041] The purpose of employing the fin-type automatic extension structure in this invention is mainly twofold:

[0042] 1. Self-protection. The automatically retractable fin structure can be retracted when not in use, which not only protects the exciter and receiver from damage, but also reduces test interruptions and increased costs due to device failure.

[0043] 2. Improve the accuracy of test data. Since seismic waves require a specific path to propagate, simply fixing the seismic wave exciter and receiver at the probe position results in an ineffective propagation path for the waves. This leads to significant interference from the probe structure and makes it impossible to obtain accurate seismic wave data. Therefore, a finned automatic extension design is necessary. This design, after deployment, forms a parallel structure within the soil layer, increasing the propagation path of the seismic waves. This allows the waves more time and space to propagate within the soil, reducing interference from the probe structure and thus minimizing signal attenuation during propagation. This contributes to improving the depth and accuracy of the test data.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] (1) Improved the problem of insufficient seismic wave excitation depth and unstable energy of the original seismic wave hole pressure static cone penetration test equipment, effectively ensuring the continuity and systematicness of signal acquisition during the measurement process, while reducing human intervention and improving the accuracy and repeatability of the signal.

[0046] (2) It can efficiently and conveniently obtain accurate seismic wave data in in-situ testing of geotechnical engineering. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of a finned automatic extension seismic wave hole pressure static cone penetration system in its retracted state.

[0048] Figure 2 This is a schematic diagram of a finned automatic extension seismic wave hole pressure static cone penetration system in its deployed state.

[0049] Explanation of markings in the diagram:

[0050] 1-Threaded connector; 2-Seismic wave exciter; 3-Exciter mounting bracket; 4-Exciter displacement switch; 5-Signal controller; 6-Rear end sleeve; 7-Seismic wave receiver; 8-Receiver mounting bracket; 9-Receiver displacement switch; 10-Signal processor; 11-Side wall sleeve; 12-Pore pressure sensor; 13-Pore pressure filter ring; 14-Conical probe; 15-Coaxial cable; 16-Acquisition device; 17-Computer; 18-Exciter silicone rubber coating; 19-Receiver silicone rubber coating. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0052] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] In the following embodiments or examples, unless otherwise specified, the functional components or structures are conventional components or structures used in the art to achieve the corresponding functions, and will not be described in detail here.

[0055] To address the issues of separation between the excitation and penetration devices in conventional seismic wave hole pressure static penetration testing systems, this invention provides a fin-type automatic extending seismic wave hole pressure static penetration testing system. (See [link to relevant documentation]). Figure 1 and Figure 2 As shown, it includes:

[0056] The rear end sleeve 6 and the side wall sleeve 11 are connected sequentially from top to bottom and are internally connected;

[0057] The conical probe 14 is connected to the lower end of the sidewall sleeve 11;

[0058] A pore pressure sensor 12 is installed at the connection between the sidewall sleeve 11 and the conical probe 14;

[0059] The seismic wave exciter 2 and seismic wave receiver 7 are installed from top to bottom on the side wall of the rear cylinder 6 and can be expanded or retracted in a fin-like manner.

[0060] A signal controller 5 and a signal processor 10 are installed inside the rear end cylinder 6. The signal controller 5 is connected to the seismic wave exciter 2, and the signal processor 10 is connected to the seismic wave receiver 7.

[0061] And a computer 17 that is connected to the signal controller 5 and the signal processor 10 via a coaxial cable 15.

[0062] In some specific embodiments, an exciter mounting bracket 3 and a receiver mounting bracket 8 are hinged to the side wall of the rear end cylinder 6, and the seismic wave exciter 2 and the seismic wave receiver 7 are respectively mounted on the exciter mounting bracket 3 and the receiver mounting bracket 8.

[0063] In a more specific embodiment, the exciter mounting bracket 3 and the receiver mounting bracket 8 are respectively mounted on the side wall of the rear end cylinder 6 via a hinge point, and the hinge point can be opened and closed by signal control. Here, the process of opening and closing the hinge point by signal control is conventional technology in the art and is not an innovative point to be protected by this invention, and will not be described in detail here.

[0064] In a more specific embodiment, the position of the hinge point satisfies the condition that it does not extend beyond the outer surface of the side wall of the rear end cylinder 6.

[0065] In a more specific embodiment, the shapes of the exciter fixing frame 3 and the receiver fixing frame 8 satisfy the following: when the upper part of the exciter fixing frame 3 and the receiver fixing frame 8 approaches the rear end cylinder 6 to its maximum extent, there is still a gap between the upper part of the exciter fixing frame 3 and the receiver fixing frame 8 and the outer surface of the side wall of the rear end cylinder 6, so as to prevent physical interference between the components.

[0066] In a more specific embodiment, the exciter mounting bracket 3 and the receiver mounting bracket 8 are respectively provided with an exciter displacement switch 4 and a receiver displacement switch 9. The signal controller 5 is connected to the seismic wave exciter 2 through the exciter displacement switch 4, and the signal processor 10 is connected to the seismic wave receiver 7 through the receiver displacement switch 9. Here, the exciter displacement switch 4 and the receiver displacement switch 9 are displacement switches commonly used in the art, and will not be described in detail here.

[0067] For example, the exciter displacement switch 4 is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm; the receiver displacement switch 9 is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm.

[0068] The main functions of the exciter displacement switch 4 and receiver displacement switch 9 in this invention are to ensure the overall stability of the exciter and receiver during probe penetration. The main functions of the exciter fixing frame 3 and receiver fixing frame 8 are to constrain the seismic wave exciter and receiver to a state where they can only deflect within a certain angle. The deflection of the exciter and receiver is mainly achieved by lifting the probe. Opening the two displacement switches allows the exciter and receiver to rotate, while opening the hinge points of the two fixing frames allows the exciter and receiver to deflect laterally from 0 to 30°. During probe lifting, the force of the soil drives the exciter and receiver to deflect. When the maximum deflection angle of 30° is reached, the signal controller sends a signal to control the seismic wave exciter to generate seismic waves. Additionally, the exciter and receiver are covered with a silicone rubber film to prevent soil from entering the rear end cylinder.

[0069] In some specific embodiments, the outer surfaces of the seismic wave exciter 2 and the seismic wave receiver 7 are respectively provided with a silicone rubber coating 18 for the exciter and a silicone rubber coating 19 for the receiver, so as to protect the exciter and the receiver from the effects of soil compression and erosion. For example, the thickness of the silicone rubber coating can be about 0.8-1.2 mm.

[0070] In some specific embodiments, the distance between the seismic wave exciter 2 and the seismic wave receiver 7 is 450–550 mm. This distance is set by taking into account the length of the probe while ensuring that the seismic waves have a certain propagation path.

[0071] In some specific embodiments, the upper end of the conical probe 14 is also provided with a pore pressure filter ring 13.

[0072] In some specific embodiments, the upper end of the rear end cylinder 6 is also connected to a threaded joint 1 for connecting to an external probe rod.

[0073] In some specific embodiments, the cone angle of the conical probe 14 is 60°, and the cross-sectional area of ​​the cone base is 10 or 15 cm². 2 .

[0074] In some specific embodiments, the height of the rear end cylinder 6 is 600-1000mm, and the cross-sectional area of ​​the lower end face of the rear end cylinder 6 is equal to the cross-sectional area of ​​the side wall sleeve 11.

[0075] In some specific embodiments, the surface area of ​​the sidewall sleeve 11 is 100-300 cm². 2 The cross-sectional area is equal to the cross-sectional area of ​​the cone bottom of the 14-cone probe.

[0076] In some specific embodiments, the thickness of the pore pressure filter ring 13 is 2-8 mm.

[0077] In some specific embodiments, the length of the seismic wave exciter 2 is 100-200 mm.

[0078] In some specific embodiments, the length of the seismic wave receiver 7 is 100-200 mm.

[0079] In some specific embodiments, the signal controller 5 includes a signal generator, a modulation module, and an output interface; the signal processor 10 includes a receiving module, a tuner, a demodulator, an amplifier, and an output module. Here, the signal controller 5 controls the hinge point of the displacement switch and the fixing frame and sends a signal to the exciter to generate seismic waves. The signal processor 10 tunes and amplifies the received seismic wave signal before outputting it. Both of these components are conventional products in the art and do not involve any innovative protection points of this invention.

[0080] On the other hand, the present invention provides a finned automatic extended seismic wave hole pressure static cone penetration test method, which is based on the finned automatic extended seismic wave hole pressure static cone penetration test system as described above, and the test method includes the following steps:

[0081] (1) A static penetration test of pore pressure is performed on the predetermined test point using conventional penetration method, and its penetration rate is controlled to be constant. At this time, the seismic wave exciter 2 and the seismic wave receiver 7 are in a retracted state.

[0082] (2) When conducting seismic wave testing, pause the penetration operation and raise the rear end cylinder 6 at a constant rate so that the seismic wave exciter 2 and the seismic wave receiver 7 can be finned and deflected laterally until the set angle is reached.

[0083] (3) The computer 17 sends an electrical signal to the signal controller 5 and transmits it to the seismic wave exciter 2, causing it to generate seismic waves in the soil and transmit them downwards until they are captured by the seismic wave receiver 7 below.

[0084] (4) After the seismic wave receiver 7 detects the signal, it is transmitted to the signal processor 10 and then output to the computer 17. After processing, the speed and characteristics of the seismic wave propagating in the underground medium are extracted.

[0085] Each of the above implementation methods can be implemented individually, or in any combination of two or more.

[0086] The above implementation methods will be described in more detail below with reference to specific embodiments.

[0087] Example 1:

[0088] To address the issues of separation between the excitation and penetration devices in conventional seismic wave borehole pressure static penetration testing systems, this embodiment provides a finned automatic extension seismic wave borehole pressure static penetration testing system. (See [link to relevant documentation]). Figure 1 and Figure 2 As shown, it includes:

[0089] The rear end sleeve 6 and the side wall sleeve 11 are connected sequentially from top to bottom and are internally connected;

[0090] The conical probe 14 is connected to the lower end of the sidewall sleeve 11;

[0091] A pore pressure sensor 12 is installed at the connection between the sidewall sleeve 11 and the conical probe 14;

[0092] The seismic wave exciter 2 and seismic wave receiver 7 are installed from top to bottom on the side wall of the rear cylinder 6 and can be expanded or retracted in a fin-like manner.

[0093] A signal controller 5 and a signal processor 10 are installed inside the rear end cylinder 6. The signal controller 5 is connected to the seismic wave exciter 2, and the signal processor 10 is connected to the seismic wave receiver 7.

[0094] And a computer 17 that is connected to the signal controller 5 and the signal processor 10 via a coaxial cable 15.

[0095] The exciter mounting bracket 3 and receiver mounting bracket 8 are hinged to the side wall of the rear cylinder 6. The seismic wave exciter 2 and the seismic wave receiver 7 are respectively mounted on the exciter mounting bracket 3 and the receiver mounting bracket 8.

[0096] The exciter mounting bracket 3 and the receiver mounting bracket 8 are respectively mounted on the side wall of the rear end cylinder 6 through a hinge point, and the hinge point can be opened and closed by signal control.

[0097] The hinge point is positioned such that it does not extend beyond the outer surface of the side wall of the rear end cylinder 6. The shapes of the exciter mounting bracket 3 and the receiver mounting bracket 8 are such that when the upper parts of the exciter mounting bracket 3 and the receiver mounting bracket 8 approach the rear end cylinder 6 to their maximum extent, a gap still exists between the upper parts of the exciter mounting bracket 3 and the outer surface of the side wall of the rear end cylinder 6. Thus, when the entire system penetrates downwards, under the force of the soil, the fin structure composed of the seismic wave exciter 2 and the exciter mounting bracket 3 will move towards the side wall of the rear end cylinder 6, exhibiting a retracted state; while when the rear end cylinder 6 is lifted upwards, under the same action of the soil, the fin structure will deflect away from the side wall of the rear end cylinder 6, exhibiting an extended state.

[0098] Please see again. Figure 1 As shown, the exciter mounting bracket 3 and the receiver mounting bracket 8 are also respectively provided with an exciter displacement switch 4 and a receiver displacement switch 9. The signal controller 5 is connected to the seismic wave exciter 2 through the exciter displacement switch 4, and the signal processor 10 is connected to the seismic wave receiver 7. For example, the exciter displacement switch 4 is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm; the receiver displacement switch 9 is a circular inductive switch with a diameter of 10-20 mm and a thickness of 6-25 mm.

[0099] The primary function of the displacement switches for the exciter and receiver is to ensure the overall stability of the exciter and receiver during probe insertion. The primary function of the exciter and receiver mounting bracket is to constrain the exciter and receiver, restricting their deflection to a certain angle. Deflection of the exciter and receiver is mainly achieved by lifting the probe. Opening the displacement switches allows the exciter and receiver to rotate, while opening the hinge points of the brackets allows for lateral deflection of 0–30°. During probe lifting, the force of the soil drives the exciter and receiver to deflect. When the maximum deflection angle of 30° is reached, the signal controller sends an electrical signal to control the seismic wave exciter to generate seismic waves, which are then propagated downwards until captured by the seismic wave receiver. The specific wave velocity calculation formula is as follows:

[0100]

[0101] Where: V—shear wave velocity (m / s);

[0102] H – Distance between the seismic wave exciter and the seismic wave receiver;

[0103] △T——The time (s) for the shear wave to travel from the seismic wave exciter to the seismic wave receiver.

[0104] The outer surfaces of the seismic wave exciter 2 and the seismic wave receiver 7 are respectively provided with a silicone rubber coating 18 for the exciter and a silicone rubber coating 19 for the receiver to protect the exciter and receiver from soil compression and erosion. For example, the thickness of the silicone rubber coating can be about 0.8-1.2 mm.

[0105] The distance between the seismic wave exciter 2 and the seismic wave receiver 7 is 450-550 mm, and for example, it can be 500 mm. The setting is based on the length of the probe, while ensuring that the seismic waves have a certain propagation path.

[0106] The upper end of the conical probe 14 is also provided with a pore pressure filter ring 13 to prevent soil particles from entering the sensor and to ensure that the internal glycerol is saturated, thus guaranteeing the continuity and accuracy of pore pressure measurement. Specifically, the thickness of the pore pressure filter ring 13 can be 2–8 mm.

[0107] The upper end of the rear cylinder 6 is also connected to a threaded connector 1 for connecting to an external probe.

[0108] The cone angle of the conical probe 14 is 60°, and the cross-sectional area of ​​the cone base is 10 or 15 cm². 2 .

[0109] The height of the rear end sleeve 6 is 600-1000mm, and the cross-sectional area of ​​the lower end face of the rear end sleeve 6 is equal to the cross-sectional area of ​​the side wall sleeve 11.

[0110] The surface area of ​​the sidewall sleeve 11 is 100-300 cm². 2 The cross-sectional area is equal to the cross-sectional area of ​​the cone bottom of the 14-cone probe.

[0111] The length of the seismic wave exciter 2 is 100-200 mm. The length of the seismic wave receiver 7 is 100-200 mm.

[0112] The signal controller 5 includes a signal generator, a modulation module, and an output interface; the signal processor 10 includes a receiving module, a tuner, a demodulator, an amplifier, and an output module. Here, the signal controller 5 controls the hinge point of the displacement switch and the fixing frame and sends a signal to the exciter to generate seismic waves. The signal processor 10 tunes and amplifies the received seismic wave signal before outputting it. Both components are conventional products in the art and do not involve any innovative points of protection in this invention.

[0113] The working principle of the testing system in this embodiment is as follows:

[0114] First, a static cone penetration test is conducted using conventional penetration methods, with the penetration rate controlled at a constant 2 cm / s to ensure uniformity of the penetration process. At this time, the exciter displacement switch 4 and the receiver displacement switch 9 are in the closed state. When seismic wave testing is required, the penetration operation is paused, and the rear end cylinder 6 is raised at the same rate of 2 cm / s. Simultaneously, the exciter displacement switch 4 and the receiver displacement switch 9 open, thereby driving the seismic wave exciter 2 and the seismic wave receiver 7 to shift. Under the constraint of the exciter mounting bracket 3 and the receiver mounting bracket 8, the seismic wave exciter 2 and the seismic wave receiver 7 undergo lateral deflection. When the deflection angle of the seismic wave exciter 2 and the seismic wave receiver 7 reaches 30°, the computer 17 begins to send an electrical signal, which is processed by the acquisition instrument 16 and transmitted to the signal controller 5 via the coaxial cable 15. Upon receiving the electrical signal, the signal controller 5 transmits it to the seismic wave exciter 2. Maintaining a stable energizing current, the seismic wave exciter 2 generates seismic waves in the soil, which continue to propagate downwards until captured by the seismic wave receiver 7. After the seismic wave receiver 7 detects the signal, it is transmitted to the signal processor 10. The signal processor 10 tunes and amplifies the received signal before outputting it to the connected computer 17 via the coaxial cable 15. The computer 17 uses appropriate software for processing, including signal denoising, amplification, and decoding, to extract the speed and characteristics of the seismic waves propagating in the subsurface medium. After the data transmission is complete, the routine penetration operation resumes, and the aforementioned seismic wave testing steps are repeated at the next predetermined detection point.

[0115] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A finned automatic extended seismic wave hole pressure static cone penetration test method, characterized in that, The testing system used in this method includes: The rear end sleeve and the side wall sleeve are connected sequentially from top to bottom and are internally connected; The conical probe is connected to the lower end of the sidewall sleeve; A bore pressure sensor is installed at the connection between the sidewall sleeve and the conical probe; A seismic wave exciter and a seismic wave receiver, which are installed from top to bottom on the side wall of the rear cylinder and can be deployed or retracted in a fin-like manner; A signal controller and a signal processor are installed inside the rear end cylinder. The signal controller is connected to the seismic wave exciter, and the signal processor is connected to the seismic wave receiver. and a computer that is connected to the signal controller and the signal processor via coaxial cables respectively; An exciter mounting bracket and a receiver mounting bracket are hinged to the side wall of the rear cylinder, and the seismic wave exciter and the seismic wave receiver are respectively mounted on the exciter mounting bracket and the receiver mounting bracket; The exciter mounting bracket and the receiver mounting bracket are respectively mounted on the side wall of the rear cylinder through a hinge point, and the hinge point can be opened and closed vertically by signal control. The position of the hinge point satisfies the condition that it does not extend beyond the outer surface of the rear cylinder sidewall. The shapes of the exciter bracket and receiver bracket satisfy the following condition: when the upper part of the exciter bracket and receiver bracket approaches the rear end cylinder to its maximum extent, there is still a gap between the upper part of the exciter bracket and receiver bracket and the outer surface of the side wall of the rear end cylinder, so as to prevent physical interference between the components. The distance between the seismic wave exciter and the seismic wave receiver is 250~350mm; When the entire system penetrates downwards, under the force of the soil, the fin structure composed of the seismic wave exciter and the exciter fixing frame will move closer to the side wall of the rear cylinder, and will be in a contracted state; when the rear cylinder is lifted upwards, under the same action of the soil, the fin structure will deflect away from the side wall of the rear cylinder, and will be in an unfolded state. The testing method includes the following steps: (1) Perform static penetration test on the predetermined test point using conventional penetration method, and control its penetration rate to be constant. At this time, the seismic wave exciter and the seismic wave receiver are in a closed state. (2) When conducting seismic wave testing, pause the penetration operation and raise the rear end cylinder at a constant rate so that the seismic wave exciter and seismic wave receiver expand in a fin-like manner and deflect laterally until the set angle is reached. (3) The computer sends an electrical signal to the signal controller and transmits it to the seismic wave exciter, causing it to generate seismic waves in the soil and transmit them downwards until they are captured by the seismic wave receiver below. (4) After the seismic wave receiver detects the signal, it is transmitted to the signal processor and then output to the computer. After processing, the speed and characteristics of the seismic wave propagating in the underground medium are extracted.

2. The finned automatic extended seismic wave hole pressure static cone penetration test method according to claim 1, characterized in that, The exciter mounting bracket and receiver mounting bracket are also equipped with an exciter displacement switch and a receiver displacement switch, respectively. The signal controller is connected to the seismic wave exciter through the exciter displacement switch, and the signal processor is connected to the seismic wave receiver through the receiver displacement switch.

3. The finned automatic extended seismic wave hole pressure static cone penetration test method according to claim 1, characterized in that, The outer surfaces of the seismic wave exciter and the seismic wave receiver are respectively provided with a silicone rubber coating for the exciter and a silicone rubber coating for the receiver.

4. The finned automatic extended seismic wave hole pressure static cone penetration test method according to claim 1, characterized in that, The upper end of the conical probe is also provided with a pore pressure filter ring; The upper end of the rear end cylinder is also connected to a threaded connector for connecting to an external probe. The cone angle of the conical probe is 60°, and the cross-sectional area of ​​the cone base is 10~15 cm². 2 .

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