Method for detecting moisture content of widely-mixed broken stone mixed soil

Abstract

The invention discloses a method for detecting the moisture content of wide aggregate gravel mixed soil. The method comprises the following steps: digging initial gravel mixed soil from an in-situ density test pit and weighing the initial gravel mixed soil; the gravel mixed soil is screened; the sieved gravel mixed soil A is weighed, and then the water content is detected; the broken stone mixed soil B which cannot be screened is crushed, the crushed broken stone mixed soil B is screened and weighed, and then the moisture content is detected; and calculating the water content of the initial gravel mixed soil according to the water content of the gravel mixed soil A and the water content of the gravel mixed soil B. According to the method, an effective moisture content detection method can be provided for the gravel mixed soil with the particle size exceeding 60 mm, and guidance is provided for field test detection personnel in the matched moisture content detection process of an in-situ density test of the gravel mixed soil with the particle size exceeding 60 mm or above.

Description

Technical Field

[0001] The invention belongs to the technical field of rock and soil testing and detection, and in particular relates to a method for detecting the moisture content of a wide-mixed crushed stone mixed soil. Background Art

[0002] The existing soil moisture content detection methods recommended by the specifications are mainly the drying method and the field alcohol combustion method. Some papers and patents also use the frying method and rapid moisture content detection methods based on different detection principles. Among the above methods, the alcohol combustion method is difficult to meet the requirements of the center temperature of the soil sample during the alcohol combustion process, and the accuracy of moisture content detection cannot be guaranteed. The accuracy of the rapid moisture content detection methods that have been studied has yet to be verified in engineering.

[0003] According to the "Standard for Geotechnical Test Methods," it is recommended to test a small number of representative gravel-soil samples with a particle size of less than 60 mm when testing moisture content. Currently, there is no scientifically proven method for testing the moisture content of gravel-soil samples with a particle size exceeding 60 mm. To obtain scientifically reliable moisture content test results for widely distributed gravel-soil samples with a particle size exceeding 60 mm, a new testing method is needed. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for detecting the moisture content of a wide-mixed crushed stone mixed soil.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a method for detecting the moisture content of a wide-set crushed stone mixed soil, comprising the following steps:

[0007] A1, the initial crushed stone mixture was dug out from the in-situ density test pit and weighed;

[0008] A2, screening of crushed stone mixed soil;

[0009] A3, weigh the sieved crushed stone mixed soil A, and then test the moisture content;

[0010] A4, crushing the gravel mixed soil B that cannot be sieved in step A2, sieving and weighing the crushed gravel mixed soil B, and then testing the moisture content;

[0011] A5. Calculate the moisture content of the initial crushed stone mixed soil based on the moisture content of crushed stone mixed soil A and crushed stone mixed soil B;

[0012] A6. Calculate the dry density of the in-situ density test samples based on the moisture content of the initial crushed stone mixed soil.

[0013] Preferably, the calculation formula for the moisture content of the initial crushed stone mixed soil in step A5 is:

[0014]

[0015] w is the moisture content of the initial crushed stone mixed soil;

[0016] m0 is the weight of the initial crushed stone mixed soil;

[0017] m1 is the weight of crushed stone mixed soil B;

[0018] w1 is the moisture content of crushed stone mixed soil B;

[0019] m2 is the weight of crushed stone mixed soil A;

[0020] w2 is the moisture content of gravel mixed soil A.

[0021] Preferably, the dry density calculation formula in step A6 is:

[0022]

[0023] Where: p, the in-situ density of the sample measured by the sand filling method or water filling method;

[0024] p d , dry density of the supporting samples for in-situ density test;

[0025] w is the moisture content of the initial crushed stone mixed soil;

[0026] m0 is the weight of the initial crushed stone mixed soil;

[0027] m1 is the weight of crushed stone mixed soil B;

[0028] w1 is the moisture content of crushed stone mixed soil B;

[0029] m2 is the weight of crushed stone mixed soil A;

[0030] w2 is the moisture content of gravel mixed soil A.

[0031] Preferably, the implementation process of step A4 includes the following steps:

[0032] S1, lay out tarpaulin on a relatively flat area near the in-situ density test pit, and place the crushed stone mixed soil B on the tarpaulin;

[0033] S2, crushing the gravel mixed soil B, and then mixing the crushed gravel mixed soil B with the crushed gravel mixed soil B;

[0034] S3, sample the crushed gravel mixed soil B using a sealed box;

[0035] S4, testing the moisture content of the sampled crushed stone mixed soil B;

[0036] S5, calculating the moisture content using the weight difference between the crushed stone mixed soil B sample before and after drying, and finally obtaining the moisture content w1 of the crushed stone mixed soil B.

[0037] Preferably, in step S4, when the moisture content is detected, the crushed stone mixed soil B is spread in a wide plate and placed in an oven to be dried until the weight of the crushed stone mixed soil B remains unchanged.

[0038] Preferably, the oven temperature is controlled at 105° C.-110° C., and the drying time is not less than 6 hours.

[0039] Preferably, in step A2, a 60 mm particle size sieve is used for screening, and the particle size of the crushed stone mixed soil A is less than 60 mm, and the particle size of the crushed stone mixed soil B is greater than 60 mm.

[0040] Preferably, in step A4, the crushed stone mixed soil B is crushed to a particle size of less than 60 mm.

[0041] The beneficial effects of the present invention are:

[0042] The method of the present invention can provide an effective moisture content detection method for crushed stone mixed soil with particle size exceeding 60 mm, and provide guidance for on-site test and inspection personnel in the process of moisture content detection in the in-situ density test of crushed stone mixed soil with particle size exceeding 60 mm. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0044] Example:

[0045] A method for detecting moisture content of a wide aggregate crushed stone mixed soil, characterized by comprising the following steps:

[0046] A1, dig out the initial crushed stone mixed soil from the in-situ density test pit and weigh it, the weight is recorded as m0;

[0047] A2, screening of crushed stone mixed soil;

[0048] A3, weigh the sieved crushed stone mixed soil A, record the weight as m2, and then test the moisture content;

[0049] A4. Crushing the crushed stone mixed soil B that cannot pass through the sieve in step A2 to a particle size of less than 60 mm. Screening and weighing the crushed crushed stone mixed soil B, with the weight recorded as m1, where m2 = m0 - m1, and then testing the moisture content.

[0050] A5. Calculate the moisture content of the initial crushed stone mixed soil based on the moisture content of crushed stone mixed soil A and crushed stone mixed soil B;

[0051] A6. Calculate the dry density of the in-situ density test samples based on the moisture content of the initial crushed stone mixed soil.

[0052] In order to ensure the accuracy of dry density, the moisture content of crushed stone mixed soil A and crushed stone mixed soil B was tested using the drying method in accordance with the "Standard for Geotechnical Test Methods".

[0053] The calculation formula for the moisture content of the initial crushed stone mixed soil in step A5 is:

[0054]

[0055] w is the moisture content of the initial crushed stone mixed soil (%);

[0056] m0 is the weight of the initial crushed stone mixed soil (Kg);

[0057] m1 is the weight of crushed stone mixed soil B (Kg);

[0058] w1 is the moisture content of crushed stone mixed soil B (%);

[0059] m2 is the weight of crushed stone mixed soil A (Kg);

[0060] w2 is the moisture content of gravel mixed soil A (%).

[0061] The dry density calculation formula in step A6 is:

[0062]

[0063] Where: p, the in-situ density of the sample measured by the sand filling method or water filling method, in g / cm 3 ;

[0064] p d , dry density of the in-situ density test supporting sample, unit is g / cm 3 ;

[0065] w is the moisture content of the initial crushed stone mixed soil;

[0066] m0 is the weight of the initial crushed stone mixed soil;

[0067] m1 is the weight of crushed stone mixed soil B;

[0068] w1 is the moisture content of crushed stone mixed soil B;

[0069] m2 is the weight of crushed stone mixed soil A;

[0070] w2 is the moisture content of gravel mixed soil A.

[0071] The implementation process of step A4 includes the following steps:

[0072] S1: On a relatively flat area near the in-situ density test pit, lay a thick, non-absorbent tarpaulin and place the crushed stone mixed soil B on the tarpaulin;

[0073] S2, crush the crushed stone mixed soil B into particles with a diameter of less than 60 mm using a hammer, and then use a shovel to mix the crushed crushed stone mixed soil B evenly;

[0074] S3, randomly sample the crushed gravel mixed soil B into sealed non-absorbent aluminum boxes and take 3 samples, each 3 kg;

[0075] S4, testing the moisture content of the three samples of crushed gravel mixed soil B respectively;

[0076] S5. Calculate the moisture content using the weight difference between the crushed gravel mixed soil B sample before and after drying. Finally, calculate an average moisture content value for the moisture content values ​​of the three samples. Finally, take the average to obtain the moisture content w1 of the crushed gravel mixed soil B. This average moisture content result represents the moisture content of the soil (rock) part with a particle size of more than 60 mm.

[0077] In step S4, when testing the moisture content, the crushed stone mixed soil B is spread in a specially made wide aluminum tray and placed in an oven to be dried until the weight of the crushed stone mixed soil B remains unchanged. The oven temperature is controlled at 105° C.-110° C. and the drying time is 7 hours.

[0078] In step A2, a 60 mm particle size sieve is used for screening, and the particle size of the crushed stone mixed soil A is less than 60 mm, and the particle size of the crushed stone mixed soil B is greater than 60 mm.

[0079] In step A4, the crushed stone mixed soil B is crushed to a particle size of less than 60 mm.

[0080] Because the soil excavated from the in-situ density test contains a certain amount of gravel mixed soil samples larger than 60mm, in order to ensure the applicability and efficiency of the drying method, the gravel mixed soil samples excavated from the in-situ density test are screened with a 60mm particle size to be selected into gravel mixed soil samples with a particle size less than 60mm and a particle size greater than 60mm. The gravel mixed soil samples with a particle size less than 60mm are mixed evenly and randomly sampled, and the gravel mixed soil samples with a particle size greater than 60mm are knocked into mixed samples with a particle size less than 60mm and randomly sampled. The following are the moisture content results of gravel mixed soil samples with a particle size less than 60mm and a particle size greater than 60mm taken from two different test pits and the moisture content results of the in-situ density test. The results effectively reflect the moisture content and dry density of wide-graded gravel mixed soil.

[0081] Table 1 Test results of gravel mixed soil backfill foundation

[0082]

[0083] Among the current moisture content testing methods, the only standard moisture content testing method that can stably control the temperature between 105°C and 110°C is the drying method. Due to the limitations of testing efficiency, when the drying method is used to test the moisture content of a crushed stone mixed soil sample with a particle size exceeding 60mm in accordance with the "Standard for Geotechnical Test Methods", the alcohol combustion method makes it difficult for the center temperature of the soil sample to reach the requirement of 105°C to 110°C during the alcohol combustion process, and its test results are often lower than those of the drying method. The method of the present invention can solve the problem of testing the moisture content of a crushed stone mixed soil sample with a particle size exceeding 60mm through the drying method.

Claims

1. A method for detecting moisture content of a wide aggregate crushed stone mixed soil, characterized in that: The following steps are involved: A1, the initial crushed stone mixture was dug out from the in-situ density test pit and weighed; A2, screening of crushed stone mixed soil; A3, weigh the sieved crushed stone mixed soil A, and then test the moisture content; A4, crushing the gravel mixed soil B that cannot be sieved in step A2, sieving and weighing the crushed gravel mixed soil B, and then testing the moisture content; A5. Calculate the moisture content of the initial crushed stone mixed soil based on the moisture content of crushed stone mixed soil A and crushed stone mixed soil B; A6. Calculate the dry density of the in-situ density test samples based on the moisture content of the initial crushed stone mixed soil.

2. A method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 1, characterized in that: The calculation formula for the moisture content of the initial crushed stone mixed soil in step A5 is: w is the moisture content of the initial crushed stone mixed soil; m0 is the weight of the initial crushed stone mixed soil; m1 is the weight of crushed stone mixed soil B; w1 is the moisture content of crushed stone mixed soil B; m2 is the weight of crushed stone mixed soil A; w2 is the moisture content of gravel mixed soil A.

3. A method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 1 or 2, characterized in that: The dry density calculation formula in step A6 is: Where: p, the in-situ density of the sample measured by the sand filling method or water filling method; p d , dry density of the supporting samples for in-situ density test; w is the moisture content of the initial crushed stone mixed soil; m0 is the weight of the initial crushed stone mixed soil; m1 is the weight of crushed stone mixed soil B; w1 is the moisture content of crushed stone mixed soil B; m2 is the weight of crushed stone mixed soil A; w2 is the moisture content of gravel mixed soil A.

4. The method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 1, wherein: The implementation process of step A4 includes the following steps: S1, lay out tarpaulin on a relatively flat area near the in-situ density test pit, and place the crushed stone mixed soil B on the tarpaulin; S2, crushing the gravel mixed soil B, and then mixing the crushed gravel mixed soil B with the crushed gravel mixed soil B; S3, sample the crushed gravel mixed soil B using a sealed box; S4, testing the moisture content of the sampled crushed stone mixed soil B; S5, calculating the moisture content using the weight difference between the crushed stone mixed soil B sample before and after drying, and finally obtaining the moisture content w1 of the crushed stone mixed soil B.

5. A method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 4, characterized in that: In step S4, when the moisture content is detected, the crushed stone mixed soil B is spread in a wide plate and placed in an oven to be dried until the weight of the crushed stone mixed soil B remains unchanged.

6. A method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 5, characterized in that: The oven temperature is controlled at 105° C.-110° C., and the drying time is not less than 6 hours.

7. The method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 1, wherein: In step A2, a 60 mm particle size sieve is used for screening, and the particle size of the crushed stone mixed soil A is less than 60 mm, and the particle size of the crushed stone mixed soil B is greater than 60 mm.

8. The method for detecting moisture content of a wide aggregate crushed stone mixed soil according to claim 1, wherein: In step A4, the crushed stone mixed soil B is crushed to a particle size of less than 60 mm.

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