Soil solidification effect detection and analysis system and method

Abstract

The invention discloses a soil solidification effect detection and analysis system and method, and relates to the field of soil solidification effect detection.The soil solidification effect detection and analysis method comprises the steps that based on the sedimentation characteristics of a solidification material, soil is divided into a bottom sedimentation sudden change zone, a middle sedimentation gradual change zone and a top sedimentation stable zone in the depth direction, and the minimum operation thickness of a sampling tool serves as the reference layer thickness; dividing non-equidistant sampling layers according to different multiples in each settlement zone to intercept columnar soil samples; performing an initial dynamic load test on the original soil sample, then performing circulating saturated water drying treatment on the same soil sample, and applying the completely same dynamic load mode again; a water circulation effect in a natural environment is simulated by performing vacuum water saturation and constant-temperature drying circulation treatment on a soil sample for multiple times and combining a dynamic load test after water damage. Through non-equal-interval stratified sampling and multi-round dry-wet cycle testing, stratified dynamic and high-precision quantitative evaluation of the water damage resistance of soil solidification is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil solidification effect detection, and relates to a soil solidification effect detection and analysis system and method. Background Art

[0002] In civil engineering, soil, when used as a foundation and building material, often suffers from insufficient bearing capacity due to its natural properties. This is particularly true in complex environments such as flooding and load fluctuations, where it is prone to structural damage such as settlement and slippage, seriously impacting the safety and stability of the project. To address these issues, soil solidification treatment technology is widely used in engineering practice. By adding solidifying materials to the soil, it improves its physical and mechanical properties, enhancing its resistance to compression, shear, and water damage.

[0003] Soil stabilization not only significantly enhances the bearing capacity of foundations but also effectively reduces deformation and extends the service life of projects. It is a key technical means of improving soil stability and environmental adaptability. Therefore, conducting a rigorous analysis of soil stabilization effectiveness is crucial.

[0004] The core of soil solidification effect analysis lies in accurately evaluating the physical and mechanical properties of the solidified soil, which usually relies on representative sampling of the solidified area. Since the soil solidification area is vast, the effect analysis relies on sampling of the solidified soil. However, in the actual solidification process, the distribution of solidifying materials in the soil is often affected by gravity, showing obvious non-uniform distribution characteristics. Traditional sampling methods usually use equal-interval layering for detection. This approach makes it difficult to accurately match the actual stress state at different depths with the spatial distribution law of the solidified materials. As a result, in the bottom solidified material-rich area, due to the large layer thickness, subtle changes in the stress concentration area may be missed. In the top area with low solidified material concentration, the sampling may be too dense, resulting in redundant detection. In addition, this unreasonable sampling method can easily lead to distortion of the dynamic load response test results, making it difficult to accurately reflect the mechanical properties and water damage resistance of the solidified soil at each depth.

[0005] Secondly, traditional soil stabilization testing methods typically only test deformation characteristics, ultimate bearing capacity, or water stability in isolation, and rely on external control group experiments for comparative analysis. This testing approach not only lacks systematicity and fails to truly reflect the comprehensive performance of soil under the influence of multiple factors, but also produces relatively simple test results, making it impossible to analyze the correlation between deformation characteristics, ultimate bearing capacity, and water stability. This limits the rigor of the test and its engineering applicability.

[0006] Furthermore, with the increasing demands placed on foundation quality in engineering construction and the continued influence of environmental factors such as the rainfall-evaporation cycle brought about by climate change, soils will experience repeated cycles of wetting and drying over long periods of service, resulting in a cumulative effect of strength degradation. Current technical approaches often rely solely on a single saturated-drying test to assess soil's resistance to water damage. This method only reflects instantaneous water absorption and softening behavior and cannot truly reproduce the strength degradation process under multiple cycles of wetting and drying. This leads to biased evaluations of soil solidification effectiveness, easily leading to overly optimistic assessments of project durability and safety, and thus creating potential risks. Summary of the Invention

[0007] In view of this, in order to solve the problems raised in the above background technology, a soil solidification effect detection and analysis system and method are proposed.

[0008] The technical solution adopted by the present invention to solve its technical problems is: in the first aspect, the present invention provides a soil solidification effect detection and analysis system, including the following modules: a step-by-step layered sampling module, an initial dynamic load module, a cyclic saturation drying module, a dynamic load module after water damage, and a layered water stability attenuation analysis module.

[0009] The stepped stratified sampling module is used to set up gradient sampling layers along the depth direction in the solidified soil area and intercept columnar soil samples from each layer.

[0010] The initial dynamic load module is used to apply axial compression and radial shear composite dynamic loads to each layer of columnar soil samples, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of each layer of columnar soil samples in the initial state.

[0011] The cyclic saturation and drying module is used to subject the columnar soil samples at the same depth that have completed the initial dynamic load test to multiple vacuum saturation and constant temperature drying cycles.

[0012] The post-water damage dynamic load module is used to re-apply the same multi-axial load mode as the initial dynamic load module to the columnar soil samples at the same depth after multiple saturation and drying cycles, and synchronously collect and record the deformation characteristics and ultimate bearing stress values of the columnar soil samples in each layer after water damage.

[0013] The layered water stability attenuation analysis module is used to compare and analyze the deformation characteristics and ultimate bearing stress attenuation rate of the same cylindrical soil sample in each layer in the initial state and the state after water damage, and calculate the softening coefficient based on the saturated strength and standard strength measurement values of each layer, and comprehensively output the mechanical attenuation and water stability change maps of the water damage resistance of solidified layers at different depths.

[0014] In a second aspect, the present invention provides a soil solidification effect detection and analysis method, including: S1. According to the settlement characteristics of the solidified material, the solidified soil area is divided into three intervals along the depth direction: a bottom settlement mutation zone, a middle settlement gradient zone and a top settlement stable zone. The minimum operable thickness of the sampling tool is used as the reference layer thickness, and the sampling layer is divided in each interval according to different multiples and columnar soil samples are intercepted.

[0015] S2. Fix each layer of columnar soil samples on a multi-axial loading platform. Apply a composite dynamic load of axial compression and radial shear, including ramp pressurization, peak load holding, and step unloading stages, using a hydraulic servo system. Record the deformation characteristics and ultimate bearing stress values of the soil samples in the initial state.

[0016] S3. Subject the columnar soil sample at the same depth as that tested after the initial dynamic load test to multiple cycles of vacuum saturation and constant temperature drying.

[0017] S4. Apply the same multiaxial loading mode again to the columnar soil samples at the same depth after multiple saturation and drying cycles, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of the columnar soil samples in each layer after water damage.

[0018] S5. Calculate the attenuation rates of the deformation characteristic parameters and the ultimate bearing stress value respectively, and calculate the softening coefficient based on the saturated strength and standard strength measurement values.

[0019] S6. Align the deformation characteristic attenuation rate of each layer, the ultimate bearing stress value attenuation rate, and the softening coefficient of the corresponding layer according to the depth coordinate, establish a performance change map with depth as the vertical axis, and comprehensively output the mechanical attenuation and water stability changes of the water damage resistance of the cured layers at different depths.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention divides the settlement interval according to the settlement characteristics of the solidified material and divides the sampling layer according to different multiple factors, which can more accurately capture the changes in soil characteristics at different depths, conduct detailed analysis of areas with significant changes in settlement characteristics, and obtain a more accurate assessment of the soil solidification effect. For areas with smaller settlement changes, a larger sampling layer thickness can be used, thereby reducing unnecessary detailed sampling workload and optimizing resource utilization.

[0021] (2) After performing an initial dynamic load test on the original soil sample, the present invention applies a cyclic saturation drying treatment to the same soil sample and then re-applies the exact same dynamic load pattern. This continuous testing method using the same sample enables direct comparison of performance changes before and after water damage, completely eliminating the data bias caused by individual sample differences in traditional methods and ensuring the high reliability and accuracy of the test results.

[0022] (3) The present invention simulates the effect of water circulation in the natural environment on the soil solidification effect by subjecting the soil sample to multiple vacuum saturation and constant temperature drying cycles, combined with dynamic load testing after water loss, and effectively evaluates the water loss resistance and stability of the soil solidification layer, ensuring safety and reliability for long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of the connection of various modules of the system of the present invention.

[0025] Figure 2 This is a flow chart for the multi-index evaluation of soil solidification effect and water loss resistance in the present invention.

[0026] Figure 3 The present invention is a flowchart of the steps for implementing the method. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] See also Figure 1 As shown, the first aspect of the present invention provides a soil stabilization effect detection and analysis system, comprising the following modules: a step-by-step sampling module, an initial dynamic load module, a cyclic saturation drying module, a post-water damage dynamic load module, and a layered water stability attenuation analysis module. All modules are connected in the order described above.

[0029] The step-by-step layered sampling module is used to set up sampling layers with gradient distribution along the depth direction in the solidified soil area to intercept columnar soil samples of each layer.

[0030] It should be noted that the solidified material will gradually settle in the soil under the action of gravity and be enriched at the bottom, thus forming an obvious concentration gradient distribution on the longitudinal profile of the soil. This sedimentation characteristic enables the gradient analysis in the depth direction to more accurately reflect its dynamic change law.

[0031] According to the settlement characteristics of the solidified materials, the soil area is divided into three settlement intervals along the depth direction: the bottom settlement mutation zone, the middle settlement gradual zone and the top settlement stable zone.

[0032] The bottom settlement mutation zone is close to the bedrock or other hard layers under the ground, and may experience rapid accumulation of solidified materials or sudden changes due to factors such as groundwater flow. It is characterized by drastic settlement changes and may contain a large amount of unevenly dispersed curing agent.

[0033] The middle settlement gradient zone is located above the bottom settlement mutation zone. As the depth decreases, the distribution of the solidified material gradually becomes uniform and the settlement rate gradually decreases, reflecting the transition from uneven to relatively uniform state, and reflecting the process in which the solidified material gradually mixes with the soil and exerts its consolidation effect.

[0034] The top settlement stabilization zone is located at the top layer. Since it is closest to the ground surface, it is greatly affected by the external environment. However, because the solidified material has enough time to diffuse and react in this area, the settlement of this area usually tends to be stable and the material distribution is relatively uniform.

[0035] It should be noted that through layered processing, the soil solidification effect at different depths can be analyzed more accurately, and how the solidification material affects the mechanical properties of each layer of soil can be understood. The sampling strategy can be adjusted according to the characteristics of different settlement intervals to ensure that while ensuring data accuracy, resources are reasonably allocated to avoid unnecessary workload and cost waste.

[0036] The minimum operable thickness of the sampling tool is used as the reference layer thickness.

[0037] It should be noted that the sampling tools may include auger samplers, piston samplers, standard penetration test equipment, thin-walled tube samplers, and the like.

[0038] Specifically, a smaller sampling layer thickness can provide finer data resolution, which helps to discover subtle differences in the physical and mechanical properties of the soil with depth. Selecting the minimum operable thickness of the sampling tool as the reference layer thickness can reasonably control the difficulty and cost of the sampling work while ensuring data quality, ensuring that each columnar soil sample can reflect the true condition of the soil at that depth, and avoiding the problem of mixing soils of different properties due to the columnar soil sample being too thick, thereby affecting the accuracy of the analysis results.

[0039] The sampling layers are divided using different multiple factors according to different settlement intervals, as follows:

[0040] a) Divide the bottom subsidence mutation zone into several sampling layers according to the base layer thickness;

[0041] b) Divide the central sedimentation gradient zone into several sampling layers according to fixed multiples of the base layer thickness;

[0042] c) Divide the top settlement stability zone into several sampling layers according to increasing multiples of the baseline layer thickness.

[0043] It should be noted that the bottom settlement mutation zone requires more detailed stratification to capture these rapidly changing information due to the dramatic changes in the distribution of solidified materials.

[0044] The characteristics of the central sedimentation gradient zone change relatively slowly. Using a fixed multiple of the base layer thickness for stratification can reduce the number of samples while ensuring data resolution.

[0045] Specifically, the fixed multiple primarily considers the speed and smoothness of changes in the physical and mechanical properties of the region. If the changes are slow, a larger multiple can be chosen; otherwise, a smaller multiple should be chosen. The specific value chosen depends primarily on historical experience. For example, if the base layer thickness is 10 cm and the central subsidence gradient changes relatively slowly, a sampling layer thickness of twice the base layer thickness (20 cm) can be chosen. If the central subsidence gradient changes rapidly, a sampling layer thickness of 1.5 times the base layer thickness can be chosen, resulting in a 15 cm thickness for each sampling layer.

[0046] As the depth of the top settlement stabilization zone decreases, the influencing factors increase, such as climate change and biological activity. However, because the upper soil layer is usually relatively uniform and easy to access, the layer thickness can be gradually increased to simplify the operation.

[0047] Specifically, the determination of the incremental multiple is usually based on the surface conditions and their impact on the underlying soil, and the layer thickness is generally increased gradually from far away from the ground to the surface.

[0048] As a specific example, from the surface to a depth of 20 cm, use 20 cm, which is twice the reference layer thickness; from 20 cm to 35 cm, use 15 cm, which is 1.5 times the reference layer thickness; from 35 cm to 47 cm, use 12 cm, which is 1.2 times the reference layer thickness; below 47 cm, use 10 cm, which is the reference layer thickness.

[0049] This zoned and graded sampling strategy can effectively capture the differences in soil properties at different depths, thereby providing a scientific basis for evaluating soil solidification effects and helping to optimize subsequent treatment measures.

[0050] The initial dynamic load module is used to apply axial compression and radial shear composite dynamic loads to each layer of columnar soil samples, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of each layer of columnar soil samples in the initial state.

[0051] It should be noted that in actual engineering applications, soil is not only subjected to vertical loads, such as the weight of buildings, but also to horizontal forces, such as earthquakes and wind pressure. By applying a composite dynamic load of axial compression and radial shear, these complex stress conditions can be simulated more realistically, and the deformation and strength characteristics of the soil in different directions can be examined simultaneously, thereby comprehensively evaluating its compressive strength, shear strength and ability to resist deformation.

[0052] The deformation characteristics and ultimate bearing stress values in the initial state directly reflect the degree of improvement in the mechanical properties of the soil before and after solidification treatment. Recording the deformation characteristics and ultimate bearing stress values in the initial state can serve as the basis or reference point for subsequent analysis, making it easier to compare performance changes after water damage or other treatments, clearly identifying the changing trends of soil properties over time, and evaluating the long-term stability of the solidification effect.

[0053] Each layer of columnar soil samples is fixed vertically on the multi-axis loading platform in layered order, and both ends of the soil samples are rigidly clamped by multi-degree-of-freedom fixtures.

[0054] It should be noted that in natural conditions or engineering applications, soil is typically vertically layered and primarily subjected to vertical pressure. Vertically securing soil samples allows for a more realistic simulation of the forces they experience in a real environment. Sequential vertical securing helps maintain the spatial relationships between sampling layers at different depths, facilitating subsequent systematic comparison and analysis of the mechanical properties of soil samples at different depths.

[0055] The multi-degree-of-freedom fixture applies different loads in the axial and radial directions to meet the needs of composite dynamic load testing, thereby comprehensively evaluating the comprehensive mechanical properties of the soil sample.

[0056] The axial loading axis is strictly aligned with the center line of the soil sample, and the radial loading heads are symmetrically arranged on the four sides of the soil sample.

[0057] It should be noted that when the axial loading axis is strictly aligned with the center line of the soil sample, it can ensure that the applied axial load acts directly on the center of gravity of the soil sample, avoiding the shear force caused by eccentricity, thereby reducing the impact of these unexpected forces on the experimental results.

[0058] The radial loading heads are symmetrically arranged on the four sides of the soil sample, which can apply radial pressure evenly in the circumferential direction, ensuring consistent stress distribution in all directions and avoiding local stress concentration that may be caused by unilateral or asymmetric loading.

[0059] A vertical circulating pressure is applied to the top of the cylindrical soil sample through a hydraulic servo system.

[0060] It should be noted that vertical cyclic pressure can simulate cyclic loads acting on soil in natural or engineering applications, such as traffic loads, seismic waves, or dynamic loads of buildings. This cyclic loading helps to study the long-term performance and fatigue characteristics of soil under repeated stress.

[0061] Hydraulic actuators are distributed at equal angles along the circumference of the side wall of the columnar soil sample and synchronously apply radial pressure inward.

[0062] Specifically, if there are four hydraulic actuators, the equal angular intervals can be divided into 0 degrees, 90 degrees, 180 degrees and 270 degrees.

[0063] The vertical cyclic pressure is dynamically loaded in three stages: ramp pressurization, peak load holding and step unloading.

[0064] Specifically, during the ramp pressurization phase, a hydraulic servo system applies vertical pressure to the top of the columnar soil sample at a constant rate, increasing the pressure linearly from zero to a preset peak pressure value. For example, the initial pressure is 0 MPa, and the peak pressure is set to 2.0 MPa based on the soil sample depth and project requirements. The pressurization rate can be 0.5 MPa / min to ensure quasi-static loading and avoid impact effects, and the loading time is 4 minutes.

[0065] During the peak load holding stage, the pressure is kept constant after the axial pressure reaches a preset peak value, and the load holding time is usually 5-10 minutes.

[0066] In the step unloading stage, the axial pressure is reduced in multiple steps, for example, each step unloads 20% of the peak pressure. After each step unloading, the pressure is kept constant for 1-2 minutes to observe the rebound behavior of the soil sample.

[0067] The slowly increasing pressure during the ramp pressurization stage reduces the risk of sudden failure of the sample due to rapid application of high stress, thereby ensuring a smooth experimental process.

[0068] The peak load holding stage keeps the maximum pressure constant for a period of time, so as to evaluate the stability of the soil sample under constant high stress.

[0069] The stepwise reduction of pressure during the step unloading stage can be used to observe whether the soil sample can partially or completely recover its original shape during the unloading process, which is helpful for analyzing the elastic recovery capacity and residual deformation of the soil sample.

[0070] The three-stage loading mode can better simulate the cyclic load changes experienced by soil in actual engineering environments.

[0071] During the axial slope pressurization stage, the radial pressure maintained the in-situ soil pressure corresponding to the sampling depth.

[0072] Specifically, the in-situ soil pressure corresponding to the sampling depth is maintained in order to simulate the stress state of the soil in the natural environment as realistically as possible, thereby ensuring that the experimental results can accurately reflect its mechanical properties.

[0073] During the axial peak load holding stage, the radial pressure is increased to the upper limit of the radial pressure in the proportion required to suppress lateral deformation.

[0074] Specifically, the ratio required to suppress lateral deformation can be determined by referring to data from previous similar experiments. In a natural environment, soil is not only subjected to the vertical pressure brought by the overlying soil layer, but also to the confining pressure provided by the surrounding medium. Appropriate adjustment of the radial pressure can help to more accurately simulate the actual stress state of the soil.

[0075] During the axial step unloading stage, the radial pressure maintains a stable upper limit value of the radial pressure.

[0076] The deformation characteristics can reflect the collapse edge of the original soil sample under the composite dynamic load and obtain the ultimate bearing capacity value more accurately.

[0077] Pressure sensors are installed on the contact surface between the axial loading section and the radial loading head of each layer of columnar soil sample to measure the axial pressure and radial pressure on the soil sample in real time during the loading process.

[0078] Using the longitudinal strain gauge group arranged from the top to the bottom of the side wall of each layer of columnar soil sample, all the axial strain values collected in real time are averaged to obtain the average axial strain of the real-time soil sample.

[0079] The product of the average axial strain and the original sampling layer thickness is taken as the axial compression deformation.

[0080] It should be noted that by laying multiple strain gauges on the side wall of the soil sample, a larger range of the sample surface can be covered, thereby capturing the strain distribution along the entire length of the sample. The axial compression deformation is one of the parameters for constructing the stress-compression deformation curve. Combined with the axial pressure value measured by the pressure sensor, a complete stress-strain relationship diagram can be drawn.

[0081] The axial pressure and the corresponding axial compression deformation are plotted point by point to generate an axial pressure-compression deformation dynamic curve.

[0082] It should be noted that observing the changing trend of the axial pressure-compression deformation dynamic curve can help identify the critical point where the soil sample transitions from elastic deformation to plastic deformation, as well as the ultimate strength when the maximum bearing capacity is reached.

[0083] The laser displacement scanner is used to continuously scan the maximum lateral diameter expansion point of each layer of columnar soil sample, and the displacement value of the point in each frame of scanning is recorded.

[0084] It should be noted that the laser displacement scanner is a non-contact measurement that will not cause any physical damage to the soil sample, ensuring the integrity of the columnar soil sample throughout the entire experimental process. It can also achieve continuous real-time monitoring of the lateral expansion points of the soil sample, providing a continuous data stream, making it easier to capture rapidly changing processes or transient phenomena.

[0085] The displacement change increment is obtained by subtracting the expansion displacements obtained from two adjacent scans, and the radial expansion velocity is obtained by dividing the displacement change increment by the scanning time interval.

[0086] The horizontal tangential strain difference of each layer of columnar soil sample is calculated by the horizontal strain gauge, and the result of multiplying the horizontal tangential strain by the diameter of the soil sample is the radial shear deformation.

[0087] The axial compression deformation, radial expansion velocity and radial shear deformation are taken as deformation characteristics.

[0088] It should be noted that the radial expansion velocity and radial shear deformation are indicators for judging whether the soil sample has reached the limit state. The calculated radial expansion velocity and radial shear deformation can provide detailed information about the deformation behavior of the soil during the stress process.

[0089] The limit state is determined to be reached when any of the following phenomena occurs during the axial ramp pressurization stage:

[0090] a) The slope of the axial pressure-compression deformation dynamic curve decreases by more than the preset slope threshold;

[0091] b) The radial expansion speed exceeds the set expansion speed threshold;

[0092] c) The radial shear deformation growth rate exceeds the preset shear growth rate threshold.

[0093] Specifically, judging the limit state during the axial slope pressurization stage can timely detect the overall damage of the soil sample when it just begins to undergo irreversible deformation.

[0094] The preset slope threshold value can be determined by reviewing historical experimental data under similar conditions and analyzing the change in the slope of the axial pressure-compression deformation dynamic curve when the limit state is reached, for example, 50%.

[0095] Similarly, the expansion rate threshold and the preset shear acceleration threshold can also be determined by reviewing historical experimental data under similar conditions.

[0096] And record the peak value of the axial pressure sensor and the peak value of the radial pressure sensor at this time.

[0097] The peak values of the axial pressure sensor and the radial pressure sensor are substituted into the Mohr-Coulomb criterion to calculate the equivalent ultimate bearing stress value.

[0098] Specifically, the basic expression of the Mohr-Coulomb criterion is: ,in, Indicates cohesion, represents the normal stress, represents the internal friction angle, Indicates shear strength.

[0099] When the cylindrical soil sample reaches the ultimate limit state, the Mohr stress circle is tangent to the shear strength envelope, and at this time, the following is satisfied: ,in, Indicates the peak value of the axial pressure sensor, Represents the peak value of the radial pressure sensor, from which the shear strength can be directly solved by the coordinates of the tangent point of the Mohr stress circle , that is, the ultimate bearing stress .

[0100] It should be noted that the essence of the Mohr-Coulomb criterion is to describe the mechanical mechanism of shear failure of soil and convert the principal stress parameters under composite load into quantitative indicators of ultimate bearing capacity, thereby accurately evaluating the strength characteristics and water loss attenuation law of consolidated soil.

[0101] The cyclic saturation and drying module is used to perform multiple vacuum saturation and constant temperature drying cycle treatments on the columnar soil samples at the same depth layer that have completed the initial dynamic load test.

[0102] It should be noted that using soil samples from the same depth can compare the responses of soil samples at different treatment stages under the same conditions, ensuring the consistency of the experimental samples in the initial state and reducing the uncertainty caused by soil quality differences.

[0103] By simulating natural wet-dry cycles, such as seasonal changes and rainfall, through cyclic treatments of vacuum saturation and constant temperature drying, the long-term stability and durability of soil under different moisture conditions can be evaluated, providing reliable realistic simulation data for the subsequent application of multiaxial loads identical to the initial dynamic load and the calculation of the attenuation rate after water damage.

[0104] The post-water damage dynamic load module is used to re-apply the same multi-axial load mode as the initial dynamic load module to the columnar soil samples at the same depth after multiple saturation and drying cycles, and synchronously collect and record the deformation characteristics and ultimate bearing stress values of the columnar soil samples in each layer after water damage.

[0105] It should be noted that applying exactly the same load pattern to the same soil sample in the initial state and the water-damaged state can eliminate interfering factors such as individual differences in soil samples and differences in loading conditions, ensure data comparability, and directly quantify the performance degradation caused by water erosion by comparing the responses of the same soil sample in the two states.

[0106] The deformation characteristics and ultimate bearing stress values of the columnar soil samples of each layer after water damage are specifically obtained by referring to the corresponding methods described in the initial dynamic load module.

[0107] The post-water damage dynamic loading module comprehensively evaluates the compressive capacity and deformation characteristics of soil after water damage, revealing its failure mechanism under dynamic loading conditions.

[0108] The layered water stability attenuation analysis module is used to compare and analyze the deformation characteristics and ultimate bearing stress attenuation rate of the same cylindrical soil sample in each layer in the initial state and the state after water damage, calculate the softening coefficient based on the saturated strength and standard strength measurement values of each layer, and comprehensively output the mechanical attenuation and water stability change maps of the water damage resistance of solidified layers at different depths.

[0109] refer to Figure 2 As shown in the figure, the differences between the axial compression deformation, radial expansion velocity and radial shear deformation after water damage and the initial values under the same multiaxial loading mode are calculated respectively, and the percentage of the ratio of the difference to the initial value is defined as the attenuation rate of each deformation characteristic parameter.

[0110] It should be noted that the attenuation rates of axial compression deformation, radial expansion velocity, and radial shear deformation are negative, and the larger the absolute value, the more the deformation after water damage decreases compared with the initial value, and the ability of the solidified soil to resist deformation is enhanced; conversely, if the value is positive or close to 0, it indicates that the deformation after water damage increases and the structural stability of the solidified soil decreases.

[0111] The difference between the ultimate bearing stress value after water damage and the initial ultimate bearing stress value is calculated, and the percentage of the ratio of the difference to the initial ultimate bearing stress value is defined as the attenuation rate of the ultimate bearing stress value.

[0112] It should be noted that the smaller the attenuation rate of the ultimate bearing stress value is and the smaller the absolute value is, that is, the smaller the difference between the ultimate stress after water damage and the initial value is, the weaker the weakening effect of water damage on strength is and the more stable the solidification effect is; conversely, the larger the attenuation rate of the ultimate bearing stress value is and the negative value is, the more significant the decrease in strength is after water damage and the poor ability of the solidified soil to resist water damage is.

[0113] The standard strength measurement value is the ultimate bearing stress value measured for columnar soil samples at the same depth under initial dynamic load.

[0114] The saturated strength measurement value is the ultimate bearing stress value measured under the corresponding dynamic load of the columnar soil sample at the same depth after water damage.

[0115] The saturated strength measurement values and standard strength measurement values of columnar soil samples of each layer are extracted in order of depth.

[0116] The ratio of the saturated strength measurement value to the standard strength measurement value is defined as the softening coefficient of each layer of columnar soil samples.

[0117] It should be noted that the softening coefficient approaches the value of 1, indicating that the strength after saturation is close to the initial strength, and the cured material has strong resistance to water damage; the softening coefficient is less than the value of 1 and the smaller the value, the greater the strength loss after saturation, and the curing effect deteriorates significantly in a water environment.

[0118] The deformation characteristic attenuation rate of each layer, the ultimate bearing stress value attenuation rate and the softening coefficient of the corresponding layer are aligned according to the depth coordinate.

[0119] A performance change map with depth as the vertical axis is established, and the deformation characteristic attenuation rate, ultimate bearing stress value attenuation rate and softening coefficient performance indicators of each depth point are synchronously mapped in the map.

[0120] Specifically, the vertical axis is the depth coordinate arranged from top to bottom in the order of sampling layers, namely the top settlement stable zone, the middle settlement gradual zone and the bottom settlement mutation zone; the horizontal axis is the deformation characteristic attenuation rate, the ultimate bearing stress attenuation rate and the softening coefficient.

[0121] When any one of the indicators, namely, the ability to resist deformation is enhanced, the curing effect after water damage is more stable, and the curing material has strong resistance to water damage, is met, the effect is judged to be enhanced; otherwise, the effect is judged to be decreased.

[0122] When the soil solidification effect is enhanced, green is used as the main color for visual marking, otherwise red is used as the main color for visual marking. When the soil solidification effect is close to the failure critical value, yellow is used as the warning color for visual marking.

[0123] refer to Figure 3 As shown, the second aspect of the present invention provides a soil solidification effect detection and analysis method, including: S1. According to the settlement characteristics of the solidified material, the solidified soil area is divided into three intervals along the depth direction: a bottom settlement mutation zone, a middle settlement gradient zone and a top settlement stable zone. The minimum operable thickness of the sampling tool is used as the reference layer thickness, and the sampling layer is divided in each interval according to different multiples and columnar soil samples are intercepted.

[0124] S2. Fix each layer of columnar soil samples on a multi-axial loading platform. Apply a composite dynamic load of axial compression and radial shear, including ramp pressurization, peak load holding, and step unloading stages, using a hydraulic servo system. Record the deformation characteristics and ultimate bearing stress values of the soil samples in the initial state.

[0125] S3. Subject the columnar soil sample at the same depth as that tested after the initial dynamic load test to multiple cycles of vacuum saturation and constant temperature drying.

[0126] S4. Apply the same multiaxial loading mode again to the columnar soil samples at the same depth after multiple saturation and drying cycles, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of the columnar soil samples in each layer after water damage.

[0127] S5. Calculate the attenuation rates of the deformation characteristic parameters and the ultimate bearing stress value respectively, and calculate the softening coefficient based on the saturated strength and standard strength measurement values.

[0128] S6. Align the deformation characteristic attenuation rate of each layer, the ultimate bearing stress value attenuation rate, and the softening coefficient of the corresponding layer according to the depth coordinate, establish a performance change map with depth as the vertical axis, and comprehensively output the mechanical attenuation and water stability changes of the water damage resistance of the cured layers at different depths.

[0129] The parameters involved in the above formula are all dimensionless and calculated numerically. The formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0130] The above embodiments may be implemented in whole or in part through software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0131] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0132] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0133] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0134] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A soil solidification effect detection and analysis system, characterized by: Includes the following modules: The stepped layered sampling module is used to set up gradient sampling layers along the depth direction in the solidified soil area and intercept columnar soil samples from each layer; The initial dynamic load module is used to apply axial compression and radial shear composite dynamic loads to each layer of columnar soil samples, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of each layer of columnar soil samples in the initial state; The cyclic saturation and drying module is used to subject the columnar soil samples at the same depth that have completed the initial dynamic load test to multiple vacuum saturation and constant temperature drying cycles; The post-water damage dynamic load module is used to re-apply the same multi-axial load mode as the initial dynamic load module to the columnar soil samples at the same depth after multiple saturation and drying cycles, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of the columnar soil samples in each layer after water damage; The layered water stability attenuation analysis module is used to compare and analyze the deformation characteristics and ultimate bearing stress attenuation rate of the same cylindrical soil sample in each layer in the initial state and the state after water damage, and calculate the softening coefficient based on the saturated strength and standard strength measurement values of each layer, and comprehensively output the mechanical attenuation and water stability change maps of the water damage resistance of solidified layers at different depths.

2. A soil solidification effect detection and analysis system according to claim 1, characterized in that: The specific contents of setting the gradient distribution of sampling layers along the depth direction in the solidified soil area are as follows: According to the settlement characteristics of solidified materials, the soil area is divided into three settlement zones along the depth direction: the bottom settlement mutation zone, the middle settlement gradual zone and the top settlement stable zone. The minimum operable thickness of the sampling tool is used as the reference layer thickness; The sampling layers are divided using different multiple factors according to different settlement intervals, as follows: a) Divide the bottom subsidence mutation zone into several sampling layers according to the base layer thickness; b) Divide the central sedimentation gradient zone into several sampling layers according to fixed multiples of the base layer thickness; c) Divide the top settlement stability zone into several sampling layers according to increasing multiples of the baseline layer thickness.

3. The soil solidification effect detection and analysis system according to claim 1, characterized in that: The specific contents of the axial compression and radial shear are as follows: Each layer of columnar soil samples is fixed vertically on the multi-axis loading platform in layered order, and both ends of the soil samples are rigidly clamped by multi-degree-of-freedom fixtures; The axial loading axis is strictly aligned with the center line of the soil sample, and the radial loading heads are symmetrically arranged on the four sides of the soil sample; Apply vertical cyclic pressure to the top of the cylindrical soil sample through a hydraulic servo system; Hydraulic actuators are distributed at equal angles along the circumference of the side wall of the columnar soil sample and synchronously apply radial pressure inward.

4. A soil solidification effect detection and analysis system according to claim 3, characterized in that: The specific implementation of the composite dynamic load is as follows: The vertical cyclic pressure is dynamically loaded in three stages: ramp pressurization, peak load holding and step unloading; During the axial slope pressurization stage, the radial pressure maintained the in-situ soil pressure corresponding to the sampling depth; During the axial peak load holding stage, the radial pressure is increased to the upper limit of the radial pressure according to the proportion required to suppress lateral deformation; During the axial step unloading stage, the radial pressure maintains a stable upper limit value of the radial pressure.

5. The soil solidification effect detection and analysis system according to claim 1, characterized in that: The specific contents of the deformation characteristics are as follows: Pressure sensors are installed on the contact surface between the axial loading section and the radial loading head of each layer of columnar soil sample to measure the axial and radial pressures on the soil sample in real time during the loading process. Using the longitudinal strain gauge group arranged from the top to the bottom of the side wall of each layer of columnar soil sample, all the axial strain values collected in real time are averaged to obtain the average axial strain of the real-time soil sample; The product of the average axial strain and the original sampling layer thickness is taken as the axial compression deformation; The axial pressure and the corresponding axial compression deformation are plotted point by point to generate a dynamic curve of axial pressure-compression deformation; The laser displacement scanner is used to continuously scan the maximum lateral diameter expansion point of each layer of columnar soil sample, and the displacement value of the point in each frame of scanning is recorded; The radial expansion velocity is obtained by subtracting the expansion displacements obtained from two adjacent scans to obtain a displacement change increment, and dividing the displacement change increment by the scanning time interval; The horizontal tangential strain difference of each layer of columnar soil sample is calculated by the horizontal strain gauge, and the result of multiplying the horizontal tangential strain by the diameter of the soil sample is the radial shear deformation; The axial compression deformation, radial expansion velocity and radial shear deformation are taken as deformation characteristics.

6. The soil solidification effect detection and analysis system according to claim 5, characterized in that: The specific content of the ultimate bearing stress value is as follows: The limit state is determined to be reached when any of the following phenomena occurs during the axial ramp pressurization stage: a) The slope of the axial pressure-compression deformation dynamic curve decreases by more than the preset slope threshold; b) The radial expansion speed exceeds the set expansion speed threshold; c) The radial shear deformation growth rate exceeds the preset shear growth rate threshold; And record the peak values of the axial pressure sensor and the radial pressure sensor at this time; The peak values of the axial pressure sensor and the radial pressure sensor are substituted into the Mohr-Coulomb criterion to calculate the equivalent ultimate bearing stress value.

7. The soil solidification effect detection and analysis system according to claim 6, characterized in that: The specific contents of the comparative analysis of the deformation characteristics and the attenuation rate of the ultimate bearing stress value of the same cylindrical soil sample in each layer in the initial state and the state after water damage are as follows: The differences between the axial compression deformation, radial expansion velocity, and radial shear deformation after water damage and their initial values under the same multiaxial loading mode were calculated, and the percentage of the difference to the initial value was defined as the attenuation rate of each deformation characteristic parameter. The difference between the ultimate bearing stress value after water damage and the initial ultimate bearing stress value is calculated, and the percentage of the ratio of the difference to the initial ultimate bearing stress value is defined as the attenuation rate of the ultimate bearing stress value.

8. The soil solidification effect detection and analysis system and method according to claim 1, characterized in that: The specific steps for calculating the softening coefficient based on the saturated strength and standard strength measurement values of each layer are as follows: The standard strength measurement value is the ultimate bearing stress value measured by the columnar soil sample at the same depth under the initial dynamic load; The saturated strength measurement value is the ultimate bearing stress value measured under the corresponding dynamic load of the columnar soil sample at the same depth after water damage; Extract the saturated strength and standard strength values of columnar soil samples of each layer in order of depth; The ratio of the saturated strength measurement value to the standard strength measurement value is defined as the softening coefficient of each layer of columnar soil samples.

9. The soil solidification effect detection and analysis system according to claim 1, characterized in that: The specific contents of the comprehensive output of mechanical attenuation and water stability change maps of water damage resistance of solidified layers at different depths are as follows: Align the deformation characteristic attenuation rate of each layer, the ultimate bearing stress value attenuation rate and the softening coefficient of the corresponding layer according to the depth coordinate; A performance change map with depth as the vertical axis is established, and the deformation characteristic attenuation rate, ultimate bearing stress value attenuation rate and softening coefficient performance indicators of each depth point are synchronously mapped in the map.

10. A soil solidification effect detection and analysis method, characterized by: include: S1. Based on the settlement characteristics of the solidified material, the solidified soil area is divided into three zones along the depth direction: a bottom sudden settlement zone, a middle gradual settlement zone, and a top stable settlement zone. Using the minimum operable thickness of the sampling tool as the baseline layer thickness, sampling layers are divided into different multiples within each zone and cylindrical soil samples are collected. S2. Secure each layer of cylindrical soil samples on a multi-axial loading platform. Apply a combined dynamic load of axial compression and radial shear, including ramp pressurization, peak load holding, and step unloading, using a hydraulic servo system. Record the deformation characteristics and ultimate bearing stress of the soil samples in the initial state. S3. Subject the soil column sample from the same depth as that tested for the initial dynamic load to multiple cycles of vacuum saturation and constant temperature drying. S4. Reapply the same multiaxial loading mode to the columnar soil samples at the same depth after multiple saturation and drying cycles, and simultaneously collect and record the deformation characteristics and ultimate bearing stress values of each layer of columnar soil samples after water damage; S5. Calculate the attenuation rate of the deformation characteristic parameter and the ultimate bearing stress value, and calculate the softening coefficient based on the saturated strength and standard strength measurement values; S6. Align the deformation characteristic attenuation rate of each layer, the ultimate bearing stress value attenuation rate, and the softening coefficient of the corresponding layer according to the depth coordinate, establish a performance change map with depth as the vertical axis, and comprehensively output the mechanical attenuation and water stability changes of the water damage resistance of the cured layers at different depths.

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