Method and device for standard penetration test on water

Abstract

This disclosure relates to the field of marine surveying technology, and provides a method and apparatus for a marine standard penetration test (SPT). The method includes: determining the predicted wave displacement at the test site for the marine SPT; calculating the first acceleration of the wave based on the predicted wave displacement; estimating the motion state of the marine platform based on the first wave acceleration and motion state parameters of the marine platform to determine the predicted displacement of the marine platform; calculating the target extension / retraction amount of the extension / retraction compensation mechanism in the marine SPT apparatus based on the predicted displacement of the marine platform and the current displacement measurement value; optimizing the control parameters of the PID controller using a particle swarm optimization algorithm to minimize the difference between the current extension / retraction amount of the extension / retraction compensation mechanism and the target extension / retraction amount; and conducting the marine SPT based on the extension / retraction motion of the extension / retraction compensation mechanism. This solution can improve the accuracy of marine SPTs.

Description

Technical Field

[0001] This disclosure relates to the field of marine surveying technology, and more specifically, to a method and apparatus for marine standard penetration testing. Background Technology

[0002] The standard penetration test (SPT) refers to the process of transferring the hammering energy of a heavy hammer to a standard penetrator at the bottom of the hole through a drill pipe, recording the number of hammer blows required for the penetrator to penetrate 30 centimeters into the soil layer, and analyzing the soil layer based on the empirical correlation between the number of hammer blows and the soil layer characteristics.

[0003] However, when conducting standard penetration tests on water, such as when conducting standard penetration tests in the sea, the offshore construction platform is affected by the marine environment and is in a floating state, making it difficult to accurately control the standard penetration depth to the required 30cm depth, thus resulting in low accuracy of the standard penetration test.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a method and apparatus for a standard penetration test on water, thereby improving the accuracy of the standard penetration test on water to at least a certain extent.

[0006] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0007] According to a first aspect of this disclosure, a method for conducting a standard penetration test on water is provided, comprising: determining a predicted wave displacement value at the test site where the standard penetration test is to be conducted on water, and calculating a first acceleration of the wave based on the predicted wave displacement value;

[0008] The motion state of the platform is estimated based on the first acceleration of the wave and the motion state parameters of the platform to determine the predicted displacement value of the platform. The platform is used to load the standard penetration test equipment.

[0009] Based on the predicted displacement value of the water platform and the current measured displacement value of the water platform, the target expansion and contraction amount of the expansion compensation mechanism in the water standard penetration test equipment is calculated.

[0010] The control parameters of the PID controller in the standard penetration test equipment are optimized according to the particle swarm optimization algorithm to minimize the difference between the current extension and retraction of the telescoping compensation mechanism and the target extension and retraction. The PID controller is used to control the servo hydraulic system to drive the telescoping compensation mechanism to perform telescoping motion. The standard penetration test is performed on the telescoping compensation mechanism based on its telescoping motion. The telescoping compensation mechanism is installed at the connection base between the standard penetration test equipment and the platform.

[0011] According to a second aspect of this disclosure, a standard penetration test apparatus for water is provided, comprising: a wave disturbance prediction module configured to determine a predicted wave displacement value at the test site where the standard penetration test is to be conducted, and to calculate a first acceleration of the wave based on the predicted wave displacement value; a platform displacement prediction module configured to estimate the motion state of the platform based on the first acceleration of the wave and motion state parameters of the platform, and to determine a predicted displacement value of the platform based on the motion state estimation result, wherein the platform is used to mount the standard penetration test equipment for water; and a target expansion / contraction determination module configured to determine the target expansion / contraction based on the wave displacement prediction value. The predicted displacement value of the water platform and the current measured displacement value of the water platform are used to calculate the target expansion and contraction amount of the expansion compensation mechanism in the water standard penetration test equipment; the expansion and contraction amount adjustment module is configured to optimize the control parameters of the PID controller in the water standard penetration test equipment according to the particle swarm optimization algorithm so as to minimize the difference between the current expansion and contraction amount of the expansion compensation mechanism and the target expansion and contraction amount, and the PID controller is used to control the servo hydraulic system to drive the expansion compensation mechanism to perform expansion and contraction movements; the test module is configured to conduct water standard penetration tests based on the expansion and contraction movements of the expansion compensation mechanism.

[0012] According to a third aspect of this disclosure, a computer program product comprising instructions is provided that, when run on a computer, causes the computer to perform the steps of the standard penetration test method for waterborne objects as described in the first aspect.

[0013] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method for standard penetration testing at sea as described in the first aspect of the above embodiments.

[0014] As can be seen from the above technical solutions, the waterborne standard penetration test method and waterborne standard penetration test apparatus in the exemplary embodiments of this disclosure have at least the following advantages and positive effects:

[0015] In some embodiments of this disclosure, the wave displacement at the test site is predicted using a wave displacement prediction sequence. The target expansion / contraction amount of the telescopic mechanism is then predicted based on the predicted wave displacement. Based on this target expansion / contraction amount, the expansion / contraction amount of the telescopic compensation mechanism is adjusted using a PID controller. Compared to related technologies, this disclosure, on the one hand, by installing a telescopic compensation mechanism at the connection base between the water platform and the standard penetration test device, can offset the impact of the water platform's vertical movement on the penetration depth of the standard penetration test, thereby improving the accuracy of the penetration depth and ultimately enhancing the accuracy of the standard penetration test. On the other hand, this disclosure uses a closed-loop control system of real-time monitoring, advanced prediction, and dynamic compensation to predict and adjust the expansion / contraction amount of the telescopic compensation mechanism, thereby reducing the latency of the PID controller in the standard penetration test and improving the response speed.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This diagram illustrates a flow chart of a standard penetration test method for waterborne applications according to an exemplary embodiment of this disclosure.

[0019] Figure 2 This diagram illustrates a flowchart of a method for obtaining a target scaling amount according to an exemplary embodiment of the present disclosure.

[0020] Figure 3 This illustration shows a flowchart of a method for obtaining the current displacement measurement value of a floating platform according to an exemplary embodiment of the present disclosure.

[0021] Figure 4 This diagram illustrates the composition of a standard penetration test apparatus for waterborne applications according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0022] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other methods, components, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0023] The terms “a,” “an,” “the,” and “the” are used in this specification to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first” and “second” are used only as markings and are not a limitation on the number of objects.

[0024] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0025] In offshore wind power projects, the Standard Penetration Test (SPT) is one of the core in-situ testing methods for foundation investigation. It is mainly used to evaluate the physical and mechanical properties of seabed soil (such as density, bearing capacity, liquefaction potential, etc.) and provide key parameters for wind power foundation design (such as monopiles, jackets, caissons, etc.).

[0026] However, offshore construction platforms are affected by the marine environment and are in a floating state, which makes it difficult to accurately control the actual penetration depth of the standard penetration test to the required 30 cm. This results in errors in the measurement of the number of hammer blows in the standard penetration test and affects the accuracy of the standard penetration test.

[0027] To address the aforementioned problems, this disclosure provides a standard penetration test method for waterborne applications, with reference to... Figure 1 The method may include:

[0028] Step S110: Determine the predicted wave displacement value at the test site where the standard penetration test will be conducted on water, and calculate the first acceleration of the wave based on the predicted wave displacement value.

[0029] Step S120: Based on the first acceleration of the wave and the motion state parameters of the platform, the motion state of the platform is estimated to determine the predicted displacement value of the platform. The platform is used to load the standard penetration test equipment.

[0030] Step S130: Based on the predicted displacement value of the water platform and the current displacement measurement value of the water platform, calculate the target expansion and contraction amount of the expansion and contraction compensation mechanism in the water standard penetration test equipment.

[0031] Step S140: Optimize the control parameters of the PID controller in the waterborne standard penetration test equipment according to the particle swarm optimization algorithm so as to minimize the difference between the current extension and contraction of the telescopic compensation mechanism and the target extension and contraction. The PID controller is used to control the servo hydraulic system to drive the telescopic compensation mechanism to perform telescopic motion.

[0032] Step S150: Conduct a standard penetration test on water based on the telescopic movement of the telescopic compensation mechanism;

[0033] The telescopic compensation mechanism is installed at the connection base between the waterborne standard penetration test equipment and the waterborne platform.

[0034] exist Figure 1 In the technical solution provided by the illustrated embodiment, wave displacement at the test site on the water is predicted using a wave displacement prediction sequence. The target expansion / contraction amount of the telescopic mechanism is then predicted based on the predicted wave displacement. Based on this target expansion / contraction amount, the expansion / contraction amount of the telescopic compensation mechanism is adjusted using a PID controller. Compared with related technologies, on the one hand, this disclosure, by installing a telescopic compensation mechanism at the connection base between the water platform and the standard penetration test device, can offset the impact of the water platform's vertical movement on the penetration depth of the standard penetration test on the water, thereby improving the penetration depth accuracy and ultimately enhancing the accuracy of the standard penetration test on the water. On the other hand, this disclosure uses a closed-loop control system of real-time monitoring, advanced prediction, and dynamic compensation to predict and adjust the expansion / contraction amount of the telescopic compensation mechanism, thereby reducing the delay of the PID controller in the standard penetration test on the water and improving the response speed.

[0035] Next, a detailed description will be given of the specific implementation method of "step S110, determining the predicted wave displacement value of the test site for conducting the standard penetration test on water, and calculating the first acceleration of the wave based on the predicted wave displacement value".

[0036] For example, the test site for conducting the standard penetration test in water is a predetermined area in the water. The test site can be customized according to the needs, and this exemplary embodiment does not impose any special limitations on it.

[0037] In one exemplary implementation, the first acceleration of the wave can be predicted at each wave arrival moment. The wave displacement refers to the displacement of the wave in the direction aligned with the standard penetration direction, i.e., the vertical displacement of the wave, which can also be understood as the wave height or amplitude. Similarly, the first acceleration of the wave can be understood as the first vertical acceleration of the wave, i.e., the acceleration of the wave in the direction perpendicular to the horizontal plane of the water at the test site.

[0038] In another exemplary embodiment, the prediction of the first acceleration of the waves can also be performed periodically, i.e., the extension and retraction of the expansion compensation mechanism can be adjusted periodically according to the method of this disclosure. For example, before conducting a standard penetration test in water, the average wave period at the test site can be measured, and the prediction of the first acceleration of the waves can be performed periodically using the average wave period as the adjustment period.

[0039] In another exemplary embodiment, when the wave period changes for more than a preset duration, such as more than 1 second, a first acceleration prediction can be made, so as to continue to execute subsequent steps to achieve the offsetting of the movement interference of the water platform caused by the waves by the extension and retraction of the telescopic compensation mechanism.

[0040] For example, the method for determining the predicted wave displacement value at the test site for conducting a standard penetration test on water includes: determining a wave displacement sequence composed of wave displacements within the most recent preset time period, inputting the wave displacement sequence into a pre-trained wave displacement prediction model, and obtaining the predicted wave displacement value based on the output of the wave displacement prediction model.

[0041] The preset duration can be customized according to needs or experience, and this exemplary implementation does not impose any special limitations on it.

[0042] For example, a Long Short-Term Memory (LSTM) network can be used to train a wave displacement prediction model. Historical wave data from the test site can be collected, and the model can be trained using this historical measured wave data. The training data covers different wave displacements and wave periods, thereby enhancing the model's generalization ability. The input to the wave displacement prediction model can be a wave displacement sequence consisting of the wave displacements of the past N seconds (sampling interval 10 milliseconds, totaling 500 data points), and the output is the predicted wave displacement value for the next M seconds. Alternatively, the input can be a wave displacement sequence consisting of the displacements of the past L waves, and the output is the predicted displacement value for the next wave.

[0043] For example, at the current moment (such as the arrival time of the current wave or the arrival time of the periodic cycle mentioned above), a wave displacement sequence composed of the wave displacements within the last 5 seconds can be obtained. This wave displacement sequence can then be input into a pre-trained wave displacement prediction model, and the wave displacement prediction value can be obtained based on the output of the wave displacement prediction model.

[0044] For example, an adaptive correction mechanism can be used to incrementally train the wave displacement prediction model, thereby improving the accuracy of the predicted wave displacement values. For instance, the predicted wave displacement values ​​can be compared with the actual measured values ​​in real time, the absolute value of the difference between the predicted and actual values ​​can be calculated, and the deviation rate can be obtained based on the ratio of this absolute value to the actual measured value. When the deviation rate exceeds a threshold, such as 8%, an online learning module can be activated to incrementally train the LSTM model using the latest 50 sets of data, ensuring the stability of predictions under complex sea conditions.

[0045] When the input to a wave displacement prediction model can be a sequence of wave displacements from the past five waves, and the output is the predicted displacement value of the next wave, the first acceleration of the wave can be obtained based on the predicted displacement value and the wave period. For example, the first acceleration of the wave can be obtained from the second derivative of the predicted displacement value with respect to the wave period.

[0046] The wave period can be a predicted period. For example, the wave displacement prediction model mentioned above can predict the time interval of the next wave based on the wave displacement sequence and the time interval between adjacent wave displacements in the wave displacement sequence, thus obtaining the predicted wave period. The wave period can also be a preset fixed value. For example, as mentioned above, the average wave period at the test site can be measured before conducting a standard penetration test on water, and the average wave period can be used as the preset wave period.

[0047] The wave displacement prediction model can take as input a wave displacement sequence consisting of the wave displacements of the past N seconds and output the wave displacement prediction value for the next M seconds. The first acceleration of the wave can be obtained by taking the second derivative of the wave displacement prediction value with respect to M seconds.

[0048] Next, a detailed description will be given of the specific implementation method of "step S120, determining the predicted displacement value of the water platform based on the first acceleration of the wave, the current displacement, velocity and second acceleration of the water platform used to load the water standard penetration test equipment".

[0049] For example, the floating platform used to mount the standard penetration test equipment is an operational platform for conducting standard penetration tests in aquatic environments, such as a floating platform. It needs to possess sufficient stability and safety to ensure the accuracy and reliability of the test. The floating platform can be customized according to the actual water conditions and requirements; this exemplary embodiment does not impose any special limitations on this.

[0050] The displacement of a floating platform can also be understood as the displacement of the floating platform in the direction consistent with the standard penetration direction, that is, the displacement of the floating platform in the direction perpendicular to the horizontal plane of the water area.

[0051] For example, one implementation of step S120 may include: constructing a Kalman filter model using the first acceleration, the displacement of the water platform, the velocity, and the second acceleration as state vectors; and predicting the displacement of the water platform based on the Kalman filter model.

[0052] For example, a motion state estimation model for a floating platform is constructed based on the Federated Kalman Filter (FKF) algorithm. The state vector includes the platform's vertical displacement Z, velocity v, acceleration a, and wave acceleration w. The FKF algorithm consists of two stages: local filtering (single sensor data processing) and main filtering (global state fusion). The state estimate is updated at preset intervals, such as every 5 milliseconds. The first acceleration is the state vector of one subsystem, while the platform's displacement, velocity, and second acceleration are the state vectors of another subsystem. These are each locally filtered, and the filtering results are then fused to obtain the predicted displacement of the platform.

[0053] Next, a detailed description will be given of the specific implementation method of "step S130, calculating the target expansion and contraction amount of the expansion and contraction compensation mechanism in the waterborne standard penetration test equipment based on the predicted displacement value of the waterborne platform and the current displacement measurement value of the waterborne platform".

[0054] In one exemplary embodiment, the telescopic compensation mechanism can be understood as a telescopic compensation cylinder. The telescopic compensation mechanism is installed at the connection base between the surface standard penetration test equipment and the surface platform.

[0055] For example, the telescopic compensation mechanism in this disclosure can be a servo-hydraulic driven telescopic compensation cylinder, such as a telescopic compensation cylinder, installed at the connection base between the standard penetration test equipment and the floating platform. The stroke design of the compensation cylinder can be determined according to requirements, such as ±500 mm, which can cover the vertical displacement of the floating platform caused by conventional waves. The response speed of the compensation cylinder can also be determined according to requirements, such as less than or equal to 10 milliseconds. The thrust can also be determined according to requirements, such as greater than or equal to 50 kN. The compensation cylinder can counteract the up-and-down floating of the floating platform through telescopic movement. The cylinder body is made of marine-grade stainless steel (316L) with chrome plating on the inner wall to ensure wear resistance and corrosion resistance in high salt spray environments.

[0056] For example, Figure 2 A flowchart illustrating a method for obtaining a target scaling amount according to an exemplary embodiment of this disclosure is shown. (Reference) Figure 2 The method may include steps S210 to S230. Wherein:

[0057] In step S210, the first extension / retraction amount is obtained based on the negative of the current displacement measurement value of the water platform.

[0058] For example, the expansion and contraction of the telescopic compensation mechanism is needed to offset the vertical movement of the platform, so the expansion and contraction of the telescopic compensation mechanism is opposite to the displacement of the platform.

[0059] For example, Figure 3 This diagram illustrates a flowchart of a method for determining the current displacement measurement value of a surface platform according to an exemplary embodiment of this disclosure. (See reference...) Figure 3 The method may include steps S310 to S330. Wherein:

[0060] In step S310, a first distance between the water platform and the horizontal plane of the water test site is measured using a rangefinder installed on the water platform.

[0061] For example, a laser rangefinder can be installed on the deck of a water platform to measure the relative distance between the water platform and the horizontal plane of the water at the test site in real time, thereby obtaining the first distance.

[0062] In step S320, the current extension amount of the telescopic compensation mechanism is obtained based on the telescopic displacement sensor installed on the piston rod of the telescopic compensation mechanism.

[0063] For example, a magnetostrictive displacement sensor can be integrated into the piston rod of a telescopic compensation mechanism, such as a compensation cylinder, to record the actual telescopic amount of the compensation cylinder.

[0064] In step S330, the current displacement measurement value of the water platform is determined based on the fusion result of the first distance and the current extension amount.

[0065] For example, the first distance and the current expansion / contraction can be combined to determine the absolute vertical displacement of the platform. For instance, the sum of the first distance and the current expansion / contraction can be used to determine the current displacement measurement of the platform.

[0066] Through steps S310 to S330 above, the actual displacement of the water platform can be indirectly derived from the complementary data of the two sensors without the need to measure water surface fluctuations. This reduces hardware costs, improves the anti-interference capability of the measurement results, and ensures the accuracy of the displacement measurement of the water platform.

[0067] In step S220, the second expansion amount is obtained by multiplying the inverse of the predicted displacement value of the water platform with a preset feedforward coefficient.

[0068] For example, the preset feedforward coefficient can be customized according to requirements, such as any value between 0.6 and 0.8.

[0069] In step S230, the target expansion and contraction amount of the expansion and contraction compensation mechanism in the waterborne standard penetration test equipment is obtained based on the sum of the first expansion and contraction amount and the second expansion and contraction amount.

[0070] For example, the target extension / retraction of the compensation cylinder can be calculated based on the measured value Z_platform and the predicted value Z_pred of the vertical displacement of the platform. For instance, the measured value corresponds to the real-time compensation amount: S_real = -Z_platform (the negative sign indicates reverse cancellation), and the predicted value corresponds to the feedforward compensation amount: S_feed = -Z_pred. Then, the target compensation amount is: S_total = S_real + S_feed × K, where K is the preset feedforward coefficient mentioned above.

[0071] Next, a detailed description will be given of the specific implementation of "step S140, optimizing the control parameters of the PID controller in the waterborne standard penetration test equipment according to the particle swarm optimization algorithm so as to minimize the difference between the current extension amount and the target extension amount of the extension compensation mechanism".

[0072] In one exemplary embodiment, the underwater standard penetration test apparatus includes a PID controller for controlling the servo hydraulic system to drive the telescopic compensation mechanism to perform telescopic motion. The control parameters of the PID controller include proportional gain, integral time, and derivative time.

[0073] For example, after obtaining the target expansion amount, the control parameters of the PID controller can be self-tuned, thereby offsetting the influence of waves on the penetration depth of the standard penetration test through the expansion and contraction motion of the compensation mechanism.

[0074] For example, the particle swarm optimization algorithm can be used to optimize the control parameters of the PID controller in real time, namely the proportional coefficient, integral time, and derivative time mentioned above. The objective function of the particle swarm optimization algorithm is to minimize the error between the current extension and the target extension of the telescopic compensation mechanism, such as minimizing the sum of the squares of the current extension and the target extension. This yields the values ​​of each control parameter of the PID controller when the sum of the squares of the current extension and the target extension is minimized. Based on these control parameter values, the control parameters of the PID controller are adjusted, and the adjusted PID controller drives the servo hydraulic system to control the telescopic compensation mechanism to perform telescopic motion.

[0075] For example, the control parameters of the PID controller can be reset once when the wave cycle changes for more than a preset time, such as 1 second, so as to ensure the compensation accuracy in different aquatic environments. Of course, as mentioned above, the control parameters of the PID controller can also be self-tuned periodically. This exemplary embodiment does not impose any special limitations on this.

[0076] Next, the specific implementation method of "step S150, conducting a standard penetration test on water based on the telescopic movement of the telescopic compensation mechanism" will be described in detail.

[0077] In one exemplary embodiment, as described above, a telescoping compensation mechanism is installed at the connection base between the surface standard penetration test equipment and the surface platform. Thus, the telescoping compensation mechanism's telescoping movement adjusts the position of the surface standard penetration test equipment on the surface platform, thereby enabling standard penetration testing and reducing the impact of wave-induced platform displacement on the penetration depth, ensuring the accuracy of the penetration depth in the surface standard penetration test.

[0078] In one exemplary embodiment, parallelogram guide frames are arranged on both sides of the telescopic compensation mechanism and connected to the slide rail of the water platform via linear bearings. The parallelogram guide frames are used to limit the horizontal displacement of the telescopic compensation mechanism.

[0079] For example, parallelogram guide frames can be arranged on both sides of the compensation cylinder and connected to the platform slide rail through linear bearings to limit the lateral displacement of the compensation mechanism and ensure that the standard penetrator always moves in the vertical direction. Self-lubricating bearings are used at the joints of the guide frames to reduce mechanical wear and reduce movement resistance.

[0080] In one exemplary embodiment, the method of this disclosure may further include: measuring the actual penetration velocity of the standard penetrator of the standard penetration test equipment for water; and when the change in the actual penetration velocity is greater than or equal to a velocity fluctuation threshold, adjusting the damping coefficient of the telescopic compensation mechanism so that the change in the actual penetration velocity is less than the velocity fluctuation threshold.

[0081] For example, in this disclosure, the accuracy of standard penetration tests at sea can be further improved by compensating for the penetration velocity. For instance, a fiber optic strain sensor can be installed on the sidewall of the standard penetrator to calculate the actual penetration velocity v_penetration by measuring the strain. When v_penetration fluctuates beyond ±0.05 m / s due to wave interference, the damping coefficient of the compensation cylinder can be adjusted to suppress sudden velocity changes during penetration and ensure the stability of the penetration velocity.

[0082] For example, the method in this disclosure may further include: after the completion of the standard penetration test in water, obtaining the original number of blows measured in the standard penetration test in water; calculating the deviation between the actual penetration velocity and the standard penetration velocity during the standard penetration test in water, and determining a correction coefficient based on the deviation; determining a corrected number of blows for the standard penetration test in water based on the product of the correction coefficient and the original number of blows, so as to perform data analysis of the standard penetration test in water based on the corrected number of blows.

[0083] For example, after a standard penetration test (SPT) is completed in water, the recorded original blow count can be corrected for wave interference by adjusting the penetration velocity to obtain a corrected blow count. Soil analysis at the test site can then be performed based on this corrected blow count. For instance, the correction method for the original blow count can be: N_corrected = N_measured × (1 + Δv / v0), where N_measured is the original blow count measured in the water SPT, N_corrected is the corrected blow count, Δv is the deviation between the actual penetration velocity and the standard penetration velocity, and v0 is the standard penetration velocity, which can be determined according to standard requirements, such as 0.1 m / s.

[0084] For example, the method in this disclosure may further include: during the standard penetration test in water, monitoring the hammering force by means of a piezoelectric force sensor installed on the top of the standard penetration hammer; when the deviation between the hammering force and the preset standard hammering force is greater than or equal to a preset value, adjusting the lifting height of the standard penetration hammer by means of the servo hydraulic system so that the deviation between the hammering force of the standard penetration hammer and the preset standard hammering force is less than the preset value.

[0085] For example, the impact force can be monitored and adjusted to ensure the stability of the penetration energy. For instance, a piezoelectric force sensor can be installed on the top of the standard penetration hammer to monitor the impact force in real time. When the impact force deviates from the standard value, such as ±5% of 63.5 kN, the lifting height of the standard penetration hammer can be adjusted via a servo motor to ensure stable impact energy and further improve the accuracy of standard penetration tests on water.

[0086] In an exemplary scenario, taking offshore wind power survey as an example, before conducting a standard penetration test (SPT) at sea, a system self-check can be initiated to check sensor communication, compensating cylinder pressure, and emergency device status. Initial wave data for a preset duration, such as 30 seconds, can be collected to initialize the LSTM model and pre-tune the PID parameters. The SPT is then adjusted to its initial position, and the laser is aligned with the preset test point on the seabed. During the SPT, the number of hammer blows is recorded every 30 centimeters of penetration, and related data such as compensating cylinder displacement, hammer force, and platform movement are stored simultaneously. When the wave period exceeds the preset period (e.g., more than 10 seconds) or the wave amplitude exceeds the preset amplitude (e.g., 5 meters), the system automatically switches to a "low-speed mode," reducing the penetration speed by 30% and extending the single-hammer interval to 2 seconds to ensure data stability. After the test, the original hammer blow count can be corrected using the aforementioned method.

[0087] For example, the standard penetration test (SPT) conducted on water in this disclosure also incorporates multiple layers of safety interlocks, including hardware-level protection and software-level monitoring. For instance, hardware-level protection may include: an overflow valve and an explosion-proof valve in the compensation cylinder's hydraulic circuit to immediately cut off the power source when system pressure is abnormal; and a shear pin installed on the top of the standard penetrator to prevent overload damage to the drill pipe. Software-level monitoring may include: activating an audible and visual alarm and pausing the test if the compensation error continuously exceeds a preset threshold (e.g., exceeding 20 mm for 5 seconds); automatically switching to a backup sensor group if sensor communication is interrupted for more than a preset duration (e.g., 3 seconds); enabling cached predictive data to maintain compensation (lasting up to 10 seconds); and urgently retrieving the standard penetrator to its initial position and locking the compensation system if the platform's tilt angle exceeds a preset angle (e.g., 10 degrees).

[0088] In addition, the emergency operation interface in this disclosure is equipped with an emergency control terminal independent of the main system, which can perform operations such as "emergency stop" and "manual recovery" through physical buttons to ensure equipment safety in extreme situations.

[0089] For example, in this disclosure, various sensors synchronously acquire data. For instance, time synchronization (synchronization error ≤ 1 μs) is achieved via Industrial Ethernet (Profinet protocol) for the following sensors: a vertical accelerometer (sampling rate 500 Hz, range ±20 g), a laser rangefinder (sampling rate 100 Hz), a wave meter (sampling rate 10 Hz), and a compensation cylinder displacement sensor (sampling rate 1000 Hz). The acquired data is preprocessed via an edge computing gateway to remove outliers (using the 3σ criterion) and compressed before transmission.

[0090] A water tank simulation test was conducted on the method of this disclosure. In a 30m×20m×5m wave tank, regular waves with wave heights of 0.5-3m and periods of 3-8s were simulated. The standard penetration test (SPT) data with and without wave compensation were compared. The results showed that without wave compensation, the deviation rate of hammer blows could reach ±15%-25%. After using the method of this disclosure for wave compensation, the deviation rate was controlled within ±3%. It can be seen that the error of the standard penetration test (SPT) data obtained after using the method of this disclosure for wave compensation is significantly reduced.

[0091] Meanwhile, a field test at sea was also conducted using the method disclosed herein, and the results showed that the method disclosed herein can effectively compensate for waves and ensure the accuracy of standard penetration test data.

[0092] The method disclosed herein achieves closed-loop control of "real-time monitoring-advance prediction-dynamic compensation", which can effectively offset the platform motion interference caused by waves, effectively improve the measurement accuracy of standard penetration test blows, and provide reliable data support for the evaluation of mechanical parameters of marine soil and rock layers.

[0093] Furthermore, it should be noted that the above figures are merely illustrative representations of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0094] Furthermore, an exemplary embodiment of this disclosure also provides a standard penetration test apparatus 400 for waterborne applications. (See reference...) Figure 4As shown, the underwater standard penetration test apparatus includes the following program modules: a wave disturbance prediction module 410, configured to determine the predicted wave displacement value at the test site for the underwater standard penetration test, and calculate the first acceleration of the wave based on the predicted wave displacement value; an underwater platform displacement prediction module 420, which estimates the motion state of the underwater platform based on the first acceleration of the wave and the motion state parameters of the underwater platform, and determines the predicted displacement value of the underwater platform based on the motion state estimation result, wherein the underwater platform is used to mount the underwater standard penetration test equipment; and a target expansion / contraction determination module 430, configured to determine the target expansion / contraction value based on the wave displacement prediction value. The predicted displacement value of the upper platform and the current displacement measurement value of the water platform are used to calculate the target expansion and contraction amount of the expansion compensation mechanism in the water standard penetration test equipment; the expansion and contraction amount adjustment module 440 is configured to optimize the control parameters of the PID controller in the water standard penetration test equipment according to the particle swarm optimization algorithm so as to minimize the difference between the current expansion and contraction amount of the expansion compensation mechanism and the target expansion and contraction amount, and the PID controller is used to control the servo hydraulic system to drive the expansion compensation mechanism to perform expansion and contraction movements; the test module 450 is configured to perform water standard penetration tests based on the expansion and contraction movements of the expansion compensation mechanism.

[0095] In one exemplary embodiment, calculating the target expansion and contraction amount of the expansion compensation mechanism in the standard penetration test equipment based on the predicted displacement value of the platform and the current displacement measurement value of the platform includes: obtaining a first expansion and contraction amount based on the negative of the current displacement measurement value of the platform; calculating a second expansion and contraction amount by multiplying the negative of the predicted displacement value of the platform and a preset feedforward coefficient; and obtaining the target expansion and contraction amount of the expansion compensation mechanism in the standard penetration test equipment based on the sum of the first expansion and contraction amount and the second expansion and contraction amount.

[0096] In one exemplary embodiment, the determination of the current displacement measurement value of the water platform includes: measuring a first distance between the water platform and the horizontal plane of the water test site using a rangefinder installed on the water platform; obtaining the current extension amount of the extension compensation mechanism based on the extension displacement sensor installed on the piston rod of the extension compensation mechanism; and determining the current displacement measurement value of the water platform based on the fusion result of the first distance and the current extension amount.

[0097] In one exemplary embodiment, determining the predicted wave displacement value at the test site for conducting a standard penetration test on water includes: determining a wave displacement sequence composed of wave displacements within the most recent preset time period, inputting the wave displacement sequence into a pre-trained wave displacement prediction model, and obtaining the predicted wave displacement value based on the output of the wave displacement prediction model.

[0098] In one exemplary embodiment, the motion state parameters include displacement, velocity, and second acceleration. The step of estimating the motion state of the water platform based on the first acceleration of the wave and the motion state parameters of the water platform to determine the predicted displacement value of the water platform includes: constructing a Kalman filter model using the first acceleration, the displacement, velocity, and second acceleration of the water platform as state vectors; and predicting the predicted displacement value of the water platform based on the Kalman filter model.

[0099] In one exemplary embodiment, the above-described device further includes a penetration speed compensation module, which can be specifically configured to: measure the actual penetration speed of the standard penetrator of the standard penetration test equipment for water; and when the change in the actual penetration speed is greater than or equal to a speed fluctuation threshold, adjust the damping coefficient of the telescopic compensation mechanism so that the change in the actual penetration speed is less than the speed fluctuation threshold.

[0100] In one exemplary embodiment, the above-described apparatus further includes a data correction module, which may be specifically configured to: after the completion of the standard penetration test in water, obtain the original number of blows measured in the standard penetration test in water; calculate the deviation between the actual penetration velocity and the standard penetration velocity during the standard penetration test in water, and determine a correction coefficient based on the deviation; determine the corrected number of blows in the standard penetration test in water based on the product of the correction coefficient and the original number of blows, so as to perform data analysis of the standard penetration test in water based on the corrected number of blows.

[0101] In one exemplary embodiment, the above-described device further includes a hammer impact force stabilization control module, which can be configured to: monitor the hammer impact force by means of a piezoelectric force sensor installed on the top of the standard penetration hammer during the standard penetration test on water; and adjust the lifting height of the standard penetration hammer by means of the servo hydraulic system when the deviation between the hammer impact force and the preset standard hammer impact force is greater than or equal to a preset value, so that the deviation between the hammer impact force of the standard penetration hammer and the preset standard hammer impact force is less than the preset value.

[0102] In one exemplary embodiment, parallelogram guide frames are arranged on both sides of the telescopic compensation mechanism and connected to the slide rail of the water platform via linear bearings. The parallelogram guide frames are used to limit the horizontal displacement of the telescopic compensation mechanism.

[0103] The specific details of each part of the above-mentioned device have been described in detail in the method section of the implementation plan. For any undisclosed details, please refer to the implementation plan of the method section, and therefore will not be repeated here.

[0104] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to exemplary embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0105] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0106] An exemplary embodiment of this disclosure also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the above-described method for standard penetration testing at sea.

[0107] In one implementation, the computer program product can be a tangible product containing a computer program, such as a computer-readable storage medium storing the computer program. The readable storage medium can be a storage medium based on electrical, magnetic, optical, electromagnetic, infrared, or other signals, including but not limited to: random access memory (RAM), read-only memory (ROM), magnetic tape, floppy disk, flash memory, hard disk drive (HDD), solid-state drive (SSD), etc. For example, the computer program product can be implemented as a non-volatile storage medium storing a computer program, such as read-only memory, NAND flash memory, etc.

[0108] In one implementation, the computer program product can be an intangible product containing a computer program. For example, the computer program product can be implemented as a virtual digital product, such as an executable file, installation package, or other digital file storing the computer program.

[0109] Computer program code can be written in one or more programming languages. Examples of programming languages ​​include C, Java, C++, and Python. Program code can execute entirely on the user's computing device, partially on the user's computing device, or as a standalone software package. It can also execute partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, such as a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via an internet connection provided by a mobile network operator).

[0110] Computer programs can be carried or transmitted via signals such as electricity, magnetism, light, electromagnetic radiation, and infrared radiation. Electronic devices can convert signals carrying computer programs into digital signals, thereby running the computer programs. When a computer program runs on an electronic device, its code is used to cause the electronic device to execute (more specifically, to execute by the processor of the electronic device) the method steps of various exemplary embodiments of this disclosure, such as the above-described method for performing standard penetration tests on water.

[0111] Those skilled in the art will understand that various aspects of this disclosure can be implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software implementations, which may be referred to as "circuit", "module" or "system" respectively.

[0112] It should be understood that this disclosure is not limited to the specific methods, steps, or structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. Those skilled in the art will readily conceive of other embodiments based on the specific implementations provided in this disclosure. Therefore, the specific implementations provided in this disclosure are merely exemplary, and the scope and spirit of this disclosure are indicated by the claims, and should cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary technical means in the art not disclosed in this disclosure.

Claims

1. A method of a water standard penetration test characterized by, The method comprises the following steps: determining a wave displacement prediction value of a test site for water-borne standard penetration test, and calculating a first acceleration of the wave according to the wave displacement prediction value; estimating a motion state of a water-borne platform according to the first acceleration of the wave and a motion state parameter of the water-borne platform, to determine a displacement prediction value of the water-borne platform, the water-borne platform being used to load a water-borne standard penetration test device; calculating a target extension amount of a telescopic compensation mechanism in the water-borne standard penetration test device based on the displacement prediction value of the water-borne platform and a current displacement measurement value of the water-borne platform; optimizing control parameters of a PID controller in the water-borne standard penetration test device according to a particle swarm optimization algorithm, to minimize a difference between a current extension amount of the telescopic compensation mechanism and the target extension amount, the PID controller being used to control a servo hydraulic system to drive the telescopic compensation mechanism to perform extension movement; performing water-borne standard penetration test based on the extension movement of the telescopic compensation mechanism; wherein the telescopic compensation mechanism is installed at a connecting base of the water-borne standard penetration test device and the water-borne platform.

2. The method of claim 1, wherein, The calculation of the target extension amount of the telescopic compensation mechanism in the water-borne standard penetration test device based on the displacement prediction value of the water-borne platform and the current displacement measurement value of the water-borne platform comprises: obtaining a first extension amount according to an inverse of the current displacement measurement value of the water-borne platform; obtaining a second extension amount by multiplying an inverse of the displacement prediction value of the water-borne platform by a preset feedforward coefficient; obtaining the target extension amount of the telescopic compensation mechanism in the water-borne standard penetration test device based on a sum of the first extension amount and the second extension amount.

3. The method of claim 1, wherein, The determination of the current displacement measurement value of the water-borne platform comprises: measuring a first distance between the water-borne platform and a horizontal plane of the test site by a range finder installed on the water-borne platform; obtaining a current extension amount of the telescopic compensation mechanism based on a telescopic displacement sensor installed on a piston rod of the telescopic compensation mechanism; determining the current displacement measurement value of the water-borne platform according to a fusion result of the first distance and the current extension amount.

4. The method of claim 1, wherein, The determination of the wave displacement prediction value of the test site for water-borne standard penetration test comprises: determining a wave displacement sequence composed of wave displacements in a preset time period, inputting the wave displacement sequence into a pre-trained wave displacement prediction model, and obtaining the wave displacement prediction value according to an output of the wave displacement prediction model.

5. The method of claim 1, wherein, The motion state parameter comprises displacement, velocity and second acceleration, and the estimation of the motion state of the water-borne platform according to the first acceleration of the wave and the motion state parameter of the water-borne platform to determine the displacement prediction value of the water-borne platform comprises: constructing a Kalman filter model with the first acceleration, the displacement, the velocity and the second acceleration of the water-borne platform as state vectors; predicting the displacement prediction value of the water-borne platform based on the Kalman filter model.

6. The method of claim 1, wherein, The method further comprises: measuring an actual penetration speed of a standard penetrator of the water-borne standard penetration test device; When the variation of the actual penetration speed is greater than or equal to the speed fluctuation threshold, the damping coefficient of the telescopic compensation mechanism is adjusted so that the variation of the actual penetration speed is less than the speed fluctuation threshold.

7. The method of claim 6, wherein, The method further comprises: After the completion of the water standard penetration test, the original hammering number measured in the water standard penetration test is obtained; The deviation between the actual penetration speed and the standard penetration speed during the water standard penetration test is calculated, and a correction coefficient is determined according to the deviation; The correction hammering number of the water standard penetration test is determined according to the product of the correction coefficient and the original hammering number, so that data analysis of the water standard penetration test is performed based on the correction hammering number.

8. The method of claim 1, wherein, The method further comprises: During the water standard penetration test, the hammering force is monitored by the piezoelectric force sensor installed on the top of the standard penetration hammer; When the deviation between the hammering force and the preset standard hammering force is greater than or equal to a preset value, the lifting height of the standard penetration hammer is adjusted by the servo hydraulic system so that the deviation between the hammering force of the standard penetration hammer and the preset standard hammering force is less than the preset value.

9. The method of claim 1, wherein, Both sides of the telescopic compensation mechanism are provided with parallelogram guide frames, and the linear bearings are connected with the water platform slide rails, and the parallelogram guide frames are used to limit the displacement of the telescopic compensation mechanism in the horizontal direction.

10. A water-based standard penetration test apparatus, characterized by, Comprise: The wave disturbance prediction module is configured to determine the wave displacement prediction value of the test site of the water standard penetration test, and calculate the first acceleration of the wave according to the wave displacement prediction value; The water platform displacement prediction module estimates the motion state of the water platform according to the first acceleration of the wave and the motion state parameters of the water platform, determines the displacement prediction value of the water platform according to the motion state estimation result, and the water platform is used to load the water standard penetration test equipment; The target telescopic amount determination module is configured to calculate the target telescopic amount of the telescopic compensation mechanism in the water standard penetration test equipment based on the displacement prediction value of the water platform and the current displacement measurement value of the water platform; The telescopic amount adjustment module is configured to optimize the control parameters of the PID controller in the water standard penetration test equipment according to the particle swarm optimization algorithm, so that the difference between the current telescopic amount of the telescopic compensation mechanism and the target telescopic amount is minimized, and the PID controller is used to control the servo hydraulic system to drive the telescopic compensation mechanism to perform telescopic movement; The test module is configured to perform the water standard penetration test based on the telescopic movement of the telescopic compensation mechanism. The test module is configured to perform the water standard penetration test based on the telescopic movement of the telescopic compensation mechanism.

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