A method and system for estimating the degree of consolidation of soft soil sites based on basic geotechnical tests

Abstract

The present invention relates to a method and system for estimating the degree of consolidation of a soft soil site preloading based on basic geotechnical tests. The method and system provide a fitting relationship between the moisture content and the degree of consolidation based on a moisture content test and a consolidation test in combination with the geotechnical test results of a previous investigation report, and estimate the degree of consolidation of the preloading preloading of the entire site. The method has a simple experimental process, high experimental parameter accuracy, and convenient acquisition, and effectively avoids tedious theoretical calculations. The method can quickly classify and count the consolidation conditions of the entire site, determine the low-consolidation area, thereby predicting possible adverse effects, and can also accurately re-reinforce the local area that does not meet the consolidation requirements.

Description

Technical Field

[0001] The invention relates to the field of soft soil loading engineering detection and calculation, and in particular to a method and system for estimating the degree of consolidation of soft soil site loading preloading based on basic geotechnical tests. Background Art

[0002] The consolidation process involves many factors such as loading amount, loading rate, loading time, soft soil permeability and permeability boundary conditions. The calculation of the degree of consolidation of soft soil preloading is mainly based on Terzaghi's one-dimensional consolidation theory and related improved theories. In the theoretical calculation formula of the degree of consolidation, the calculation procedure is cumbersome, many parameters are involved, and it is difficult to accurately obtain the value. In addition, the derivation process of the theoretical method itself introduces many assumptions. Therefore, the conventional calculation method of the degree of consolidation of soft soil preloading is complicated to use, and the calculation results have large errors. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a method for estimating the degree of consolidation of soft soil sites based on basic geotechnical tests to achieve the above-mentioned purpose. The technical solution of the present invention is directly based on moisture content test and consolidation test, combined with the geotechnical test results of the previous investigation report, to give a fitting relationship between moisture content and consolidation degree, and to estimate the degree of consolidation of the entire site based on this relationship. The consolidation situation of the entire site can be quickly classified and counted, and the low-consolidation area can be determined, thereby predicting possible adverse effects, and accurately re-reinforcement treatment can be carried out on local areas that do not meet the consolidation requirements.

[0004] A method for estimating the degree of consolidation of soft soil sites based on basic geotechnical tests, the steps of which include:

[0005] S1. Take the original soil sample after the heap consolidation at the investigation site, determine the final loading of the soil sample according to the on-site heap loading, and the stable deformation of the soil sample under the final loading is the total deformation of the soil sample;

[0006] S2. Test the moisture content of the original soil sample: within the range of 0 to the final loading amount of consolidation, determine the multi-level loading amount of the original soil sample during the consolidation process, and measure the compression increment and moisture content of the original soil sample when the deformation is stable under each level of loading amount;

[0007] S3. Calculate the initial compression n of the original soil sample after consolidation with heap loading when the loading amount is 0;

[0008] S4. Substitute the compression increment and initial compression n of the original soil sample at each level of loading into the consolidation degree calculation formula, calculate the consolidation degree of the original soil sample at each level of loading, and fit it with the moisture content of the original soil sample at each level of loading to obtain the fitting formula of consolidation degree and moisture content;

[0009] S5. According to the fitting formula and in combination with the moisture content of the original soil samples at each sampling point in the survey site, the consolidation degree of each sampling point is obtained, and a distribution map of the consolidation degree of soft soil at the loading site is obtained.

[0010] The calculation of the final consolidation load is to take a typical point in the middle of the soft soil layer to calculate its total stress under the preloading pile load and its own weight, that is, the vertical stress of the preloading pile load plus the self-weight stress of the point in the middle of the soft soil layer is added to obtain the total vertical stress, and the total vertical stress is the final consolidation load.

[0011] Further, step S2 includes: measuring the moisture content of the original soil sample, loading the original soil sample from a loading amount of 0 to multiple loading amounts between 0 and the final loading amount of consolidation through a consolidation experiment, measuring the compression increment and water loss of the original soil sample when it is stable under each loading amount, and converting the water loss into the moisture content of the original soil sample under multiple loading amounts.

[0012] The initial compression amount n of the original soil sample after loading consolidation when the loading amount is 0 is calculated by finding the moisture content from the corresponding soil sample porosity of the moisture content of the original soil sample before and after loading consolidation, and then calculating the relationship between the porosity and the height of the original soil sample before and after loading consolidation.

[0013] Step S3 includes:

[0014] Extract the moisture content and porosity of the original soil samples at different times before loading consolidation from the exploration report of the exploration site, and obtain the moisture content-porosity formula by fitting;

[0015] Substitute the moisture content of the original soil sample at the exploration site into the moisture content-porosity formula to obtain the porosity e of the original soil sample when the loading amount is 0 after heap consolidation. 1 ;

[0016] According to the pore ratio e of the original soil sample before loading and consolidation in the survey report, 0 The porosity ratio of the original soil sample is 1 and the thickness of the original soil sample h 1 Bring in h 0 =(h 1 +n), calculate the initial compression n, h of the original soil sample when the loading amount is 0 after the pile consolidation 0 It is the thickness of the original soil sample before loading and consolidation.

[0017] The soil consolidation degree is the ratio between the soil compression and the total soil compression. The soil compression is the sum of the initial compression n of the original soil sample when the loading is 0 and the compression increment of the soil sample at each level of loading. The total soil compression is the ratio of the soil compression of the original soil sample at the final consolidation loading to the estimated consolidation degree.

[0018] A system for estimating the degree of consolidation of a soft soil site by preloading based on basic geotechnical tests, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the system implements the method for estimating the degree of consolidation of a soft soil site by preloading based on basic geotechnical tests described in steps S1 to S5 when the processor executes the computer program.

[0019] The present invention provides a method for estimating the degree of consolidation of a soft soil site by preloading based on basic geotechnical tests. The method is directly based on a moisture content test and a consolidation test, and combined with the geotechnical test results of a previous investigation report, to give a fitting relationship between moisture content and consolidation degree, and estimate the degree of consolidation of the whole site by preloading. The method has a simple experimental process, high experimental parameter accuracy, and convenient acquisition, and effectively avoids tedious theoretical calculations. The method can also quickly classify and count the consolidation conditions of the whole site, determine the low-consolidation area, thereby predicting possible adverse effects, and can also accurately re-reinforce local areas that do not meet the consolidation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of unidirectional compression of soil sample;

[0021] Figure 2 It is the fitting curve diagram between porosity and water content;

[0022] Figure 3 It is the fitting curve diagram between degree of consolidation and water content; DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0024] A method for estimating the degree of consolidation of soft soil sites based on basic geotechnical tests. The specific implementation process is as follows:

[0025] S1. Take the original soil sample after the heap loading consolidation at the investigation site and determine the final loading amount of the soil sample consolidation according to the on-site heap loading amount;

[0026] S2. Test the moisture content of the original soil sample: determine the multi-level loading of the original soil sample during the consolidation process within the range of loading amount from 0 to the final loading amount of consolidation, load the original soil sample from loading amount 0 to each level of loading amount, and measure the compression increment and moisture content of the soil sample when the deformation is stable under each level of loading amount;

[0027] S3. Calculate the initial compression n of the original soil sample after consolidation with heap loading when the loading amount is 0;

[0028] S4. Substitute the compression increment and initial compression n of the soil sample at each level of loading into the consolidation degree calculation formula, calculate the consolidation degree of the soil sample at various loading amounts, and fit it with the moisture content of the soil sample at various loading amounts to obtain the fitting formula of consolidation degree and moisture content;

[0029] S5. According to the fitting formula and in combination with the moisture content of the soil samples at the exploration site, the degree of consolidation of each exploration point at the exploration site is obtained, and a distribution map of the degree of consolidation of the exploration site is obtained.

[0030] A system for estimating the degree of consolidation of a soft soil site by preloading based on basic geotechnical tests, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for estimating the degree of consolidation of a soft soil site by preloading based on basic geotechnical tests described in steps S1 to S5 is implemented.

[0031] Specifically, the loading consolidation in step S1 refers to filling soil and rocks on the soft soil foundation to consolidate and compact the foundation. The on-site loading amount in the loading consolidation is determined according to the "Technical Specification for Building Foundation Treatment" (JGJ79-2012), and equal load preloading or overload preloading can be adopted. The calculation of the final loading amount of consolidation is to take a typical point in the middle of the soft soil layer to calculate its total stress under the preloading load and deadweight, that is, the vertical stress of the preloading load plus the deadweight stress of the point in the middle of the soft soil layer to obtain the total vertical stress, and the total vertical stress is the final loading amount p4 of consolidation.

[0032] Further, the step S2 includes: measuring the water content of the original soil sample, loading the original soil sample from a loading amount of 0 to various loading amounts between 0 and the final loading amount of consolidation through a consolidation experiment, measuring the compression increment and water loss of the original soil sample when it is stable under various loading amounts, and converting the water loss into the water content of the original soil sample under various loading amounts;

[0033] For example: the same original soil sample is divided into 5 parts, each with the same mass and volume, and then a consolidation-moisture content combined test is carried out. One part of the original soil sample is placed in a constant temperature drying oven to dry, and then its moisture content M and moisture content are measured. According to the size of the final consolidation load p4, the loading amounts of each level are designed to be 0, p1, p2, p3, and p4. Then, according to the actual consolidation curve, the loading stabilization time of each level of load is determined. Another 4 undisturbed soil samples are taken to conduct 4 groups of consolidation tests. The loading process of each group is as follows: the first group of loading is from 0 to loading p1, the second group of loading is from 0 to loading p1 and then to loading p2, the third group of loading is from 0 to loading p1, then loading p2 and finally loading p3, the fourth group of loading is from 0 to loading p1, then loading p2, then loading p3, and finally loading p4. The compression increment of the soil sample when different loading amounts are stable is measured and recorded as 0, a1, a2, a3, and a4; and the water loss of the soil after the loading consolidation is completed under the 4 groups of different loading conditions is tested. The water content of the soil after the loading consolidation is obtained by subtracting the water loss under each loading condition from the water content of the undisturbed soil sample, and the water content is converted into water content and recorded as w0, w1, w2, w3, and w4 respectively.

[0034] Further, according to the actual settlement-time relationship curve, after the p4 loading is stable, the estimated consolidation degree of the original soil sample can reach 0.95. The compression of the soil that has not undergone loading consolidation in the early stage of soil sample deposition is taken as 0, and the consolidation degree of the soil sample is 0 at this time. The original soil sample taken out from the stratum has undergone a certain amount of loading consolidation. Although it rebounds after unloading, the rebound amount is very small. The original soil sample has been compressed compared with the original soil sample in the early stage of deposition. Therefore, in the present invention, when the loading amount is 0, the consolidation degree of the original soil sample is not 0. At this time, it is assumed that the compression amount of the original soil sample is n, that is, the compression amount of the original soil sample is n, and the consolidation degree of the soil is the ratio between the compression amount of the soil and the total compression amount of the soil. After calculation, the consolidation degree expression under each loading in Table 1 can be obtained. The relationship between the consolidation settlement and time usually shows a trend of gradually stabilizing. In the early stage of consolidation, due to the discharge of pore water and the rearrangement of soil particles, the soil will undergo a large settlement. As time goes by, the pore water is gradually discharged, the contact between soil particles becomes closer, the compressibility of the soil decreases, and the settlement rate gradually decreases. Finally, when the soil reaches a stable state, the settlement will no longer change significantly over time. This relationship can be quantitatively studied through consolidation tests. In the consolidation test, by applying a certain pressure to the soil and measuring the settlement at different times, a settlement-time curve can be drawn. By analyzing the curve, the consolidation characteristics and settlement laws of the soil can be understood, providing an important basis for engineering design and construction. The soil consolidation degree is the ratio between the soil compression and the total soil compression. The soil compression is the sum of the initial compression n of the original soil sample when the loading is 0 and the compression increment of the original soil sample at each level of loading. The total soil compression is the ratio of the soil compression of the original soil sample at the final loading of consolidation to the estimated consolidation degree.

[0035] Table 1 Analysis of consolidation-moisture content combined test results

[0036]

[0037] Furthermore, according to Table 1, if we need to obtain the relationship between moisture content and consolidation degree, we need to know the consolidation degree under each loading amount. The consolidation degree in Table 1 is expressed by algebraic expressions, and there is an unknown number n in the algebraic expressions, so it is necessary to calculate the compression amount of the original soil sample.

[0038] Specifically, the initial compression amount n of the original soil sample when the loading amount is 0 is calculated by finding the water content from the corresponding soil sample porosity through the water content of the original soil sample before and after loading consolidation, and then calculating the porosity based on the relationship between the porosity and the height of the original soil sample before and after loading consolidation. Step S3 includes:

[0039] Extract the water content and porosity of the original soil samples at different times before loading consolidation from the exploration report of the exploration site, and fit the water content-porosity formula;

[0040] Substitute the moisture content of the original soil sample at the exploration site into the moisture content-porosity formula to obtain the porosity e of the original soil sample when the loading amount is 0 after heap consolidation. 1 ;

[0041] According to the porosity of the original soil sample before loading and consolidation in the survey report, 0 and the porosity of the original soil sample 1 and the thickness of the original soil sample h 1 Bring in h 0 =(h 1 +n), calculate the initial compression n of the original soil sample when the loading amount is 0 after the heap consolidation;

[0042] For example, according to multiple survey reports of the original soil sample before loading and consolidation, the average water content and average porosity of the soft soil corresponding to each survey report are obtained, and a fitting curve between the porosity and water content is obtained. When the loading amount of the original soil sample after loading and consolidation is 0, the measured water content is w0. According to the fitting curve between the porosity and water content, the porosity when the water content is w0 is e. 1 By consulting the investigation report after loading the original soil sample, the average water content is w1. According to the fitting curve between porosity and water content, the porosity when the water content is w1 is e. 1 .

[0043] The stratum loading compression is the same as the consolidation test, which is a unidirectional compression consolidation. Unidirectional consolidation refers to the consolidation of the soil under unidirectional pressure and unidirectional seepage of pore water under certain conditions. Therefore, Figure 1 As shown in the figure, the thickness of the original soil sample before loading consolidation is h 0 mm, the original soil sample is compressed to h under the action of 0 loading after consolidation. 1 mm,h 0 =(h 1 +n), the thickness of the original soil sample when the loading amount is 0 is h 1 =20mm.

[0044] Further calculation based on unidirectional consolidation can be obtained:

[0045]

[0046]

[0047] Due to e 1 and e 0 Both can be obtained through the fitting curve between porosity and water content. Therefore, the value of the compression amount n of the original soil sample when the loading amount is 0 can be obtained through Formula 2.

[0048] Furthermore, by substituting the compression value n of the original soil sample into Table 1, the degree of consolidation under various loading conditions in the consolidation test can be calculated. Combined with the moisture content under various loading conditions, the consolidation degree-moisture content fitting formula can be obtained.

[0049] Furthermore, in geotechnical construction, the moisture content of soil samples at each survey point can be calculated. The degree of consolidation corresponding to the soil samples at each survey point can be calculated through the above-calculated consolidation degree and moisture content fitting formula. The consolidation degree of soil samples in each area can be marked on the geotechnical construction drawing to obtain the consolidation degree distribution map of the construction site.

[0050] Furthermore, based on all the calculated consolidation degrees, the consolidation degrees of soil samples were divided into five categories: code 1 represents soil samples with a consolidation degree greater than 0.8, code 2 represents soil samples with a consolidation degree greater than 0.6, code 3 represents soil samples with a consolidation degree greater than 0.4, code 4 represents soil samples with a consolidation degree greater than 0.5, and code 5 represents soil samples with a consolidation degree less than 0.3. Finally, the proportion of each type of soil sample was counted.

[0051] Furthermore, in actual investigation, according to the positions of the sampling points provided in the geotechnical test results, the areas with low consolidation degree are marked at the corresponding positions of the boreholes in the three-dimensional geological map. According to the distribution of the low-consolidation areas, the adverse conditions that may occur in the soft soil preloading site can be predicted or local treatment can be carried out.

[0052] Example 1

[0053] Taking the secondary platform of a mine dump slope as an example, the landslide pushed the primary platform to move about 10m toward the free surface, and the front edge of the landslide rose, with an area of ​​about 2000m. 2 The total volume of uplift is about 7000m 2 . At the shear outlet of the landslide, a lake mud layer with a thickness of about 1m can be seen being squeezed out. The base of the mine dump is a lake-phase soft soil layer, and no treatment was performed before dumping. As the dumping elevation and load continued to increase, the sliding force of the slope of the dump increased, but the base lake-phase soft soil could not be consolidated in time, resulting in low shear strength of the soft soil layer. When the sliding force is close to and greater than the sliding force, a landslide is triggered. In order to further analyze the landslide mechanism of this slope and provide a reference for subsequent landslide control measures, it is necessary to estimate the overall consolidation degree of the site.

[0054] Step 1: Determine the final loading for the test

[0055] According to the current status of the spoil dump, the stable compression amount under the pressure of 400kPa in the consolidation test is taken as the total compression amount, that is, p4 is 400kPa.

[0056] Step 2: Measure the moisture content of the original soil sample after the heap consolidation at the investigation site: within the range of 0 to the final consolidation load, load the original soil sample from 0 to various loads, and measure the compression increment and moisture content of the original soil sample when it is stable under various loads;

[0057] Take three samples of the same undisturbed soil, each with the same mass and volume, and then carry out a consolidation test. Since p4 is 400kPa, the loading amounts at each level are 0, 150kPa, and 400kPa respectively. Carry out multiple groups of consolidation tests as mentioned above, measure the compression increments of the undisturbed soil samples when different loading amounts are stable, and record them as 0, 1.95, 2.26, and 3.08; and test the original moisture content of the undisturbed soil samples and the water loss of the undisturbed soil body of each group of undisturbed soil samples under different loading conditions after the loading and consolidation are completed, and then convert them into moisture contents corresponding to the moisture contents, which are recorded as 34.3%, 26.1%, 24.4%, and 22.3% respectively.

[0058] Step 3: Query the porosity according to the water content of the original soil sample under various loading amounts, and calculate the initial compression amount n of the original soil sample when the loading amount is 0 after the loading consolidation according to the porosity and compression increment of the original soil sample before the heap consolidation and under various loading amounts;

[0059] According to the analysis of the settlement-time curve of the consolidation test, it can be seen that after loading at 400 kPa for 1 hour, the compression can reach 95% of the total compression. Therefore, the consolidation degree corresponding to the compression is taken as 0.95. The compression of the soil that has not experienced loading consolidation at the initial stage of sample deposition is taken as 0. At this time, the consolidation degree of the soil sample is 0. The original soil sample taken out from the stratum has experienced a certain amount of loading consolidation. Although it rebounds after unloading, the original soil sample has been compressed compared with the original soil sample at the initial stage of deposition. Therefore, in the present invention, when the loading amount is 0, the consolidation degree of the original soil sample is not 0. At this time, it is assumed that the compression amount of the original soil sample is n. The soil consolidation degree is the ratio between the soil compression amount and the total soil compression amount. According to formula (1), the consolidation degree expression under each loading in Table 2 can be obtained.

[0060] Table 2 Analysis of consolidation-direct shear combined test results 2

[0061]

[0062] According to Table 2, if we need to obtain the relationship between water content and consolidation degree, we need to know the consolidation degree under each loading amount. The consolidation degree in Table 1 is expressed by algebraic expressions, and there is an unknown number n in the algebraic expressions. Therefore, it is necessary to calculate the compression amount of the original soil sample.

[0063] Specifically, assuming that the water content of the soft soil is the initial water content when no loading is applied before the initial loading consolidation, the corresponding consolidation degree is 0. According to the previous investigation report, the average water content of the soft soil in 2008 was 50.11%, and the porosity ratio was 1.236; the average water content of the soft soil in 2016 was 33.30%, and the porosity ratio was 0.908; the average water content of the soft soil in 2023 was 27.90%, and the porosity ratio was 0.777. Figure 2 As shown, by fitting these three sets of data, a fitting curve between the porosity and the water content and a fitting formula (3) can be obtained. The fitting curve is approximately a straight line, and the fitting coefficient R 2 The value is 0.9979, which shows a high degree of fit.

[0064] y = 2.0391 x + 0.2171 (3)

[0065] The soil sample used in this embodiment is as described above. After the loading consolidation and before the pressurization consolidation, that is, when the loading is 0, the measured water content is 34.3%. Substituting the water content 34.3% into x in formula (3) yields the porosity e: 1 is 0.9165,

[0066] Furthermore, the formation loading compression is a unidirectional compression consolidation like the consolidation test. Figure 1 As shown, the sample used for the above consolidation test is (20+n)mm in the initial condition when the stratum is not loaded and consolidated. The soil sample is compressed to 20mm under the load of the soil in the spoil dump, and then taken out of the stratum and used as the sample for the consolidation test to carry out the indoor consolidation test. The above test process does not consider the unloading rebound of the soil sample.

[0067] Substituting the calculated value into the above formula (1) yields:

[0068]

[0069] Thus, n=3.334 mm is calculated.

[0070] Substituting the calculated n value into Table 2, the degree of consolidation under various loading conditions in the consolidation test can be calculated. Combined with the moisture content under various loading conditions, the consolidation degree-moisture content fitting curve can be obtained as follows: Figure 3 As shown in the fitting formula (5), the fitting error R of the fitting curve is 2 The value is 0.9994, which shows a high degree of fit.

[0071] y = -3.4227x + 1.7093 (5)

[0072] In this January 2023 survey report, a total of 69 undisturbed soil samples were tested for moisture content. The sampling depth of undisturbed soil samples is mostly between 15-25m, except for a few that are above 30m. To simplify the problem and use existing research results, it is assumed that the depth of the overlying soil of the undisturbed soil samples is 20m and the consolidation pressure is 400kPa. The compression corresponding to the 400kPa consolidation pressure is the total compression of the undisturbed soil sample, and the consolidation degree of each undisturbed soil sample can be calculated based on Formula 5.

[0073] The calculated consolidation degree is divided into five categories: code 1 represents the original soil sample with a consolidation degree greater than 0.8, code 2 represents the original soil sample with a consolidation degree greater than 0.6, code 3 represents the original soil sample with a consolidation degree greater than 0.4, code 4 represents the original soil sample with a consolidation degree greater than 0.5, and code 5 represents the original soil sample with a consolidation degree less than 0.3. Finally, the proportion of each type of original soil sample is statistically analyzed. The calculation results, i.e., the classification of consolidation degree, are shown in Table 3 below.

[0074] Table 3 Calculation of consolidation degree of bored soil samples in January 2023

[0075]

[0076]

[0077]

[0078] From Table 3 above, we can know that among all the borehole samples, the original soil samples with a degree of consolidation greater than 0.8 accounted for 34.8%, the original soil samples with a degree of consolidation greater than 0.6 accounted for 40.6%, the original soil samples with a degree of consolidation greater than 0.4 accounted for 14.5%, the original soil samples with a degree of consolidation greater than 0.2 accounted for 3.9%, and the original soil samples with a degree of consolidation less than 0.2 accounted for 7.2%. If the borehole sampling in the January 23 survey report is representative and can characterize the consolidation of the soft soil strata of the entire site, then the following conclusions can be drawn from the above data processing and analysis: about 75% of the soft soil in the site has reached a consolidation degree of more than 0.6. However, due to the complexity of the strata and the unevenness of the consolidation degree, there are still about 10% of the soft soil in the strata that is unconsolidated or has a very low degree of consolidation. The occurrence of landslides is closely related to this part of the soil with low consolidation.

Claims

1. A method for estimating the degree of consolidation of soft soil sites based on basic geotechnical tests, the steps of which include: S1. Take the original soil sample after the heap loading consolidation at the investigation site and determine the final loading amount of the soil sample consolidation according to the on-site heap loading amount; S2. Test the moisture content of the original soil sample: within the range of 0 to the final loading amount of consolidation, determine the multi-level loading amount of the original soil sample during the consolidation process, and measure the compression increment and moisture content of the original soil sample when the deformation is stable under each level of loading amount; S3. Calculate the initial compression n of the original soil sample after heap consolidation when the loading amount is 0. Find the porosity of the soil sample corresponding to the water content through the water content of the original soil sample before and after heap consolidation. Then calculate the initial compression n based on the relationship between the porosity and the height of the original soil sample before and after heap consolidation. The calculation process is: Extract the moisture content and porosity of the original soil samples at different times before loading consolidation from the exploration report of the exploration site, and obtain the moisture content-porosity formula by fitting; Substitute the moisture content of the original soil sample at the survey site into the moisture content-porosity formula to obtain the porosity e1 of the original soil sample when the loading amount is 0 after heap consolidation; Then, according to the porosity ratio e0 of the original soil sample before loading and consolidation, the porosity ratio e1 of the original soil sample, and the thickness h1 of the original soil sample in the investigation report, the , h0=(h1+n), calculate the initial compression n of the original soil sample when the loading amount is 0 after loading consolidation, h0 is the thickness of the original soil sample before loading consolidation; S4. Substitute the compression increment and initial compression n of the original soil sample at each level of loading into the consolidation degree calculation formula, calculate the consolidation degree of the original soil sample at each level of loading, and fit it with the moisture content of the original soil sample at various loading levels to obtain the fitting formula of consolidation degree and moisture content; S5. According to the fitting formula and in combination with the moisture content of the original soil samples at each sampling point in the survey site, the consolidation degree of each sampling point is obtained, and a distribution map of the consolidation degree of soft soil at the loading site is obtained.

2. The method for estimating the degree of consolidation of soft soil sites by preloading based on basic geotechnical tests according to claim 1 is characterized in that: The final consolidation load is calculated by calculating the total vertical stress in the middle of the soft soil layer based on the pre-compression pile load, and the total vertical stress is the final consolidation load.

3. The method for estimating the degree of consolidation of soft soil sites by preloading based on basic geotechnical tests according to claim 1 is characterized in that: The step S2 comprises: measuring the moisture content of the original soil sample, loading the original soil sample from a loading amount of 0 to various loading amounts between 0 and the final loading amount of consolidation through a consolidation experiment, measuring the compression increment and water loss of the original soil sample when it is stable at various loading amounts, and converting the water loss into the moisture content of the original soil sample at various loading amounts.

4. The method for estimating the degree of consolidation of soft soil sites by preloading based on basic geotechnical tests according to claim 1 is characterized in that: The soil consolidation degree is the ratio between the soil compression and the total soil compression. The soil compression is the sum of the initial compression n of the original soil sample when the loading is 0 and the compression increment of the soil sample at each level of loading. The total soil compression is the ratio of the soil compression of the original soil sample at the final consolidation loading to the estimated consolidation degree.

5. A system for estimating the degree of consolidation of soft soil sites by preloading based on basic geotechnical tests, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for estimating the degree of consolidation of a soft soil site based on basic geotechnical tests according to steps S1 to S5 of any one of claims 1 to 4 is implemented.

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