An apparatus for evaluating thixotropic properties of marine sediments
Patent Information
- Application Number
- CN202522306535.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-10-31
AI Technical Summary
上述两种方法虽然直接，但局限性也很明显，如有破坏性，需取样或现场扰动，无法重复监测同一位置，另外也有时效性，仅能获取离散时间点的数据，难以捕捉动态过程，且操作复杂依赖专业设备与人员，成本较高，因此需要更高效的方法
[0019]1、本实用新型采用四极等距法，四个测量电极位于同一深度等间距的一条直线上，试验电流流入外侧两个电极，接地电阻测试仪通过测得试验电流和内侧两个电极间的电位差，通过简单计算即可得到电阻率。采用等距四极法具有以下优势：第一，消除了接触电阻影响：四探针法通过分离电流探针（外侧两针）和电压探针（内侧两针），避免了电流路径中接触电阻对电压测量的干扰；第二，减少了焦耳热效应：电压探针仅测量电位差，无需大电流，降低了焦耳热引起的温升，避免材料因发热导致电阻率变化，提升了测量稳定性；第三，高精度与宽范围测量；第四，非破坏性检测：探针轻触样品表面即可完成测量，避免对材料造成损伤；第五，快速检测：只需通过观察电压表的变化即可检测；第六，减少了样品表面要求：对样品表面污染不敏感，容忍表面粗糙度，无需严格清洁或抛光，简化操作流程；第七，电流场稳定：等距探针在材料表面形成对称的电流分布，避免了局部电流密度过高或过低，确保测量结果更接近材料真实电阻率。
Smart Images
Figure CN224840023U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a device for evaluating the thixotropic properties of marine sediments. Background Technology
[0002] Marine soil, as the core carrier of marine engineering foundations, exhibits thixotropy as a key engineering property. Thixotropy refers to the characteristic of soil (especially cohesive soil) to undergo structural damage and strength reduction under mechanical disturbance (such as stirring and vibration), but gradually recover its strength after resting. This property directly determines the strength recovery capacity and stability of foundation soil after construction disturbances (such as drilling, excavation, and vibration). Improper evaluation or incorrect selection can easily lead to major engineering risks such as foundation instability and platform settlement, severely restricting the efficiency of marine resource development and the progress of marine economic development.
[0003] Thixotropy causes changes in soil structure, such as structural damage after disturbance and reformation after resting. These structural changes can affect soil conductivity, or resistivity. Resistivity reflects characteristics such as soil internal structure, pore water distribution, and ion migration. Resistance measurement, as an indirect method, can monitor changes in soil structure in real time. Changes in soil structure affect the distribution of pore water and ion migration, thus altering resistivity. When soil is disturbed, structural damage leads to a decrease in resistivity; upon resting and recovery, the structure rebuilds, and resistivity rises again. This correlation provides the theoretical basis for the resistance method. Resistivity measurements are commonly used to assess soil conductivity and may be related to soil moisture, pore structure, and ion content. Therefore, monitoring changes in resistivity may indirectly reflect the thixotropic process.
[0004] Studying soil thixotropy through resistivity measurement is an innovative method combining soil mechanics and electrical properties. Traditional measurement methods, such as the vane shear test (which calculates the thixotropic recovery rate by measuring the change in shear strength of the soil before and after disturbance) or the penetration test (which records the change in penetration resistance over time to assess structural recovery), are direct but have significant limitations. They may involve destructive processes requiring sampling or in-situ disturbance, making it impossible to repeatedly monitor the same location. Furthermore, they are time-sensitive, only providing data at discrete time points, making it difficult to capture dynamic processes. They are also complex to operate, relying on specialized equipment and personnel, and are costly. Therefore, a more efficient method is needed. Utility Model Content
[0005] To address the aforementioned technical problems, this utility model provides a simple and easy-to-operate device for evaluating the thixotropic properties of marine sediments.
[0006] The technical solution of this utility model to solve the above-mentioned technical problems is: a device for evaluating the thixotropic properties of marine sediments, comprising an acrylic glass container filled with soil samples, and further comprising:
[0007] A resistivity measurement module, housed inside an acrylic glass container, is used to measure the resistivity change of a soil sample in real time and continuously during a thixotropic process. The resistivity measurement module includes an electrode array, which is embedded in the soil sample in a non-invasive structure and keeps in contact with the soil sample surface.
[0008] The vibration adjustment module, installed at the bottom of the acrylic glass container, is used to apply a controllable vibration frequency to the soil sample to simulate the mechanical disturbance during the thixotropic process.
[0009] The data processing module is electrically connected to the output of the resistivity measurement module. It is used to continuously collect and process resistivity data and convert it into digital signals. It calculates thixotropic performance parameters based on resistivity change data and a preset model.
[0010] The control module is configured to dynamically adjust the frequency and intensity of the alternating electric field and control the measurement timing.
[0011] The display and storage unit is used to display the resistivity change curve and thixotropic performance parameters in real time, and to store the raw data and calculation results.
[0012] The automated control unit is used to coordinate the operation of each module and realize unmanned operation of the experimental process. The automated control unit is electrically connected to the output of the data processing module, the vibration adjustment module, the control module, and the display and storage unit.
[0013] The aforementioned marine sediment thixotropic property evaluation device includes an electrode array comprising a first probe, a second probe, a third probe, and a fourth probe. Two first holes are symmetrically arranged on both sides of the top of an acrylic glass container, and two second holes are symmetrically arranged in the middle of the top of the acrylic glass container. The first and second probes are inserted into the two first holes and maintain contact with the soil sample. The first probe is connected to the second probe via a first wire, passing through an ammeter and a constant current source. The third and fourth probes are inserted into the two second holes and maintain contact with the soil sample. The third probe is connected to the fourth probe via a second wire, passing through a voltmeter. The outputs of the ammeter and voltmeter are connected to an Arduino microcontroller, which is connected to a host computer.
[0014] In the aforementioned marine sediment thixotropic property evaluation device, the first and second probes are both platinum-iridium alloy type A probes, and the third and fourth probes are both platinum-iridium alloy type D probes.
[0015] In the aforementioned marine sediment thixotropic property evaluation device, the first probe, the third probe, the fourth probe, and the second probe are arranged sequentially and located on the same straight line.
[0016] In the aforementioned marine sediment thixotropic property evaluation device, the distances between the first and third probes, the distances between the third and fourth probes, and the distances between the fourth and second probes are equal.
[0017] The aforementioned marine sediment thixotropic property evaluation device uses a vibration adjustment module, which is a vibration table. An acrylic glass container is placed on the vibration table, and the soil sample is mechanically disturbed by setting the vibration frequency before the experiment.
[0018] The beneficial effects of this utility model are as follows:
[0019] 1. This utility model adopts the four-electrode equidistant method, in which four measuring electrodes are located on a straight line at the same depth and equidistant distance. The test current flows into the two outer electrodes, and the grounding resistance tester obtains the resistivity by measuring the test current and the potential difference between the two inner electrodes through simple calculation. The equidistant four-pole method offers the following advantages: First, it eliminates the influence of contact resistance: by separating the current probes (two outer probes) and the voltage probes (two inner probes), it avoids interference from contact resistance in the current path on voltage measurement. Second, it reduces the Joule heating effect: the voltage probes only measure the potential difference, requiring no large current, thus reducing the temperature rise caused by Joule heating and preventing resistivity changes due to material heating, thereby improving measurement stability. Third, it provides high precision and a wide measurement range. Fourth, it is a non-destructive testing method: the probes only need to lightly touch the sample surface to complete the measurement, avoiding damage to the material. Fifth, it enables rapid detection: detection can be performed simply by observing changes in the voltmeter. Sixth, it reduces sample surface requirements: it is insensitive to sample surface contamination, tolerates surface roughness, and does not require strict cleaning or polishing, simplifying the operation process. Seventh, it provides a stable current field: the equidistant probes form a symmetrical current distribution on the material surface, avoiding excessively high or low local current densities and ensuring that the measurement results are closer to the true resistivity of the material.
[0020] 2. The structure of this utility model is reasonable and reliable. The probe can complete the measurement by lightly touching the sample surface without damaging the original soil sample. The experiment can achieve continuous monitoring and higher accuracy. The experiment is simple to operate and the process is convenient. No professional personnel are required to operate it, and the application range is wider. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall structure of the marine sediment thixotropic property evaluation device of this utility model.
[0022] Figure 2 This is a schematic diagram of the four-pole equidistant method.
[0023] Figure 3 This is a schematic diagram of an acrylic glass container. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0025] like Figures 1-3 As shown, a device for evaluating the thixotropic properties of marine sediments includes an acrylic glass container 10 filled with a soil sample, and further includes:
[0026] A resistivity measurement module is installed inside an acrylic glass container 10 for real-time and continuous measurement of the resistivity change of a soil sample during a thixotropic process. The resistivity measurement module includes an electrode array, which is embedded in the soil sample in a non-invasive structure and keeps in contact with the soil sample surface.
[0027] A vibration adjustment module, installed at the bottom of the acrylic glass container 10, is used to apply a controllable vibration frequency to the soil sample to simulate the mechanical disturbance during the thixotropic process.
[0028] The data processing module is electrically connected to the output of the resistivity measurement module. It is used to continuously collect and process resistivity data and convert it into digital signals. It calculates thixotropic performance parameters based on resistivity change data and a preset model.
[0029] The control module is configured to dynamically adjust the frequency and intensity of the alternating electric field and control the measurement timing.
[0030] The display and storage unit is used to display the resistivity change curve and thixotropic performance parameters in real time, and to store the raw data and calculation results.
[0031] The automated control unit is used to coordinate the operation of each module and realize unmanned operation of the experimental process. The automated control unit is electrically connected to the output of the data processing module, the vibration adjustment module, the control module, and the display and storage unit.
[0032] The electrode array includes a first probe 1, a second probe 4, a third probe 2, and a fourth probe 3. Two first holes 9 are symmetrically arranged on both sides of the top of the acrylic glass container 10, and two second holes 11 are symmetrically arranged in the middle of the top of the acrylic glass container 10. The first probe 1 and the second probe 4 are respectively inserted into the two first holes 9 and maintain contact with the soil sample. The first probe 1 is connected to the second probe 4 by a first wire 7 through an ammeter 5 and a constant current source 8. The third probe 2 and the fourth probe 3 are respectively inserted into the two second holes 11 and maintain contact with the soil sample. The third probe 2 is connected to the fourth probe 3 by a second wire through a voltmeter 6. The output terminals of the ammeter 5 and the voltmeter 6 are connected to an Arduino microcontroller, which is connected to a host computer.
[0033] The first probe 1 and the second probe 4 are both platinum-iridium alloy type A probes, and the third probe 2 and the fourth probe 3 are both platinum-iridium alloy type D probes. The first probe 1, the third probe 2, the fourth probe 3, and the second probe 4 are arranged sequentially and on the same straight line. The distance between the first probe 1 and the third probe 2, the distance between the third probe 2 and the fourth probe 3, and the distance between the fourth probe 3 and the second probe 4 are equal.
[0034] The vibration adjustment module is a vibration table. The acrylic glass container 10 is placed on the vibration table. The vibration frequency is set before the experiment to mechanically disturb the soil sample.
[0035] The working process of this utility model is as follows:
[0036] Step 1: Clean the inner wall of the acrylic glass container 10 thoroughly, ensuring it is dry and clean; check the ammeter 5 and voltmeter 6 to ensure they are working properly.
[0037] Step 2: Connect ammeter 5, voltmeter 6, and Arduino microcontroller;
[0038] Step 3: Place the soil sample in acrylic glass container 10 and perform the initial measurement using the four-pole equidistant method;
[0039] like Figure 2 As shown, the four-electrode equidistant method is as follows: four measuring electrodes, namely the first probe 1, the third probe 2, the fourth probe 3, and the second probe 4, are located on a straight line with equal spacing at the same depth. The test current flows into the first probe 1 and the second probe 4. The grounding resistance tester can obtain the resistivity by measuring the test current and the potential difference between the third probe 2 and the fourth probe 3.
[0040] Step 4: Place the acrylic glass container 10 on a vibration table and vibrate it.
[0041] Step 5: Apply the set test current to the first probe 1 and the second probe 4 using the constant current source 8. After the voltage stabilizes, record the values of ammeter 5 and voltmeter 6 (sample 10 times and take the average value); verify using reverse current: switch the current direction +I→-I, repeat the measurement, and the deviation between the two measurement results should be <5%;
[0042] Step Six: Repeat the measurement at the set experimental interval; import the values from ammeter 5 and voltmeter 6 into the host computer;
[0043] Step 7: The host computer automatically generates a time-resistivity line graph based on the recorded data from ammeter 5 and voltmeter 6;
[0044] Step 8: Determine the strength of the thixotropic properties of marine soil by observing the fluctuations in the time-resistivity graph.
[0045] The performance parameters of marine soil thixotropic properties include the thixotropic strength coefficient (TSC) and the structural recovery time (SRT). SRT is determined by the inflection point of the second derivative of the resistivity time series. TSC = Δρ / Δt, where Δρ is the change in resistivity after shear disturbance and Δt is the time to recover to steady state.
Claims
1. A device for evaluating the thixotropic properties of marine sediments, comprising an acrylic glass container filled with a soil sample, characterized in that, Also includes: A resistivity measurement module, housed inside an acrylic glass container, is used to measure the resistivity change of a soil sample in real time and continuously during a thixotropic process. The resistivity measurement module includes an electrode array, which is embedded in the soil sample in a non-invasive structure and keeps in contact with the soil sample surface. The vibration adjustment module, installed at the bottom of the acrylic glass container, is used to apply a controllable vibration frequency to the soil sample to simulate the mechanical disturbance during the thixotropic process. The data processing module is electrically connected to the output of the resistivity measurement module. It is used to continuously collect and process resistivity data and convert it into digital signals. It calculates thixotropic performance parameters based on resistivity change data and a preset model. The control module is configured to dynamically adjust the frequency and intensity of the alternating electric field and control the measurement timing. The display and storage unit is used to display the resistivity change curve and thixotropic performance parameters in real time, and to store the raw data and calculation results. The automated control unit is used to coordinate the operation of each module and realize unmanned operation of the experimental process. The automated control unit is electrically connected to the output of the data processing module, the vibration adjustment module, the control module, and the display and storage unit.
2. The marine sediment thixotropic property evaluation device according to claim 1, characterized in that, The electrode array includes a first probe, a second probe, a third probe, and a fourth probe. Two first holes are symmetrically arranged on both sides of the top of the acrylic glass container, and two second holes are symmetrically arranged in the middle of the top of the acrylic glass container. The first probe and the second probe are respectively inserted into the two first holes and maintain contact with the soil sample. The first probe is connected to the second probe by a first wire through an ammeter and a constant current source. The third probe and the fourth probe are respectively inserted into the two second holes and maintain contact with the soil sample. The third probe is connected to the fourth probe by a second wire through a voltmeter. The output terminals of the ammeter and the voltmeter are connected to an Arduino microcontroller, and the Arduino microcontroller is connected to a host computer.
3. The marine sediment thixotropic property evaluation device according to claim 2, characterized in that, The first and second probes are both platinum-iridium alloy type A probes, and the third and fourth probes are both platinum-iridium alloy type D probes.
4. The marine sediment thixotropic property evaluation device according to claim 2, characterized in that, The first probe, the third probe, the fourth probe, and the second probe are arranged sequentially and located on the same straight line.
5. The marine sediment thixotropic property evaluation device according to claim 2, characterized in that, The distances between the first and third probes, the distances between the third and fourth probes, and the distances between the fourth and second probes are equal.
6. The marine sediment thixotropic property evaluation device according to claim 1, characterized in that, The vibration adjustment module is a vibration table. An acrylic glass container is placed on the vibration table, and the soil sample is mechanically disturbed by setting the vibration frequency before the experiment.