Rapid detection method for compaction quality of special roadbed
Through the regression sand filling method and light-weight power touch detection test data, the compaction degree regression curve equation was established, which solved the problem of long and low efficiency of roadbed compaction quality detection in the existing technology, and achieved rapid and efficient compaction quality detection.
Patent Information
- Application Number
- CN202510092937.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-05-06
AI Technical Summary
In the prior art, the sand filling method used to detect the compaction quality of the roadbed has a long detection time, occupying the construction work surface, inefficient, and difficult to meet the rapid progress of the construction progress.
Through the relationship between the regression sand filling method compaction test and the light-powered touch detection test data, a faster compaction quality detection method is obtained. The specific steps include collecting data, performing N-order curve regression to obtain the regression curve equation of compaction degree, and performing rapid detection of compaction mass based on this equation.
It realizes rapid measurement of the compaction quality of special roadbeds, improves the inspection efficiency, avoids the problem of long-term detection time occupying the construction work surface, and saves the use of testing equipment and materials.
Smart Images
Figure CN119933200A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of fine-grained soil roadbed filling compaction quality detection, and more specifically, to a special roadbed compaction quality rapid detection method. Background Art
[0002] The construction design of special roadbed treatment in collapsible loess areas, one of the methods is cement soil compaction piles, the design requires a compaction coefficient of 0.96, equivalent to a compaction degree of 96% detected by the sand injection method. The existing method for testing compaction quality is mainly to use the sand injection method, which requires the use of a variety of testing equipment, and the testing process is long, occupies the construction work surface, is inefficient, and is not conducive to the rapid progress of construction. Summary of the invention
[0003] One purpose of the present invention is to provide a method for quickly detecting the compaction quality of a special roadbed, and to obtain a faster compaction quality detection method by using the relationship between the data of a regression sand filling method compaction test and an on-site light dynamic probing test.
[0004] In order to solve the above technical problems, the present invention provides a method for quickly detecting the compaction quality of a special roadbed, comprising the following steps: Step 1: Collect the soil penetration depth of fixed number of hammer strikes or the number of hammer strikes at fixed depth of soil penetration corresponding to the compaction degree of sand filling method and light dynamic penetration test for the same material, the same construction process, the same site and construction location; Step 2: Comprehensively analyze the collected data pairs, and make N-time curve regressions with the compaction degree of the sand filling method and the light dynamic penetration test data to obtain the regression curve equation of the compaction degree; Step 3: Perform a quick test of compaction quality based on the regression curve equation.
[0005] Preferably, the compaction degree measured by the on-site sand injection method is between 93% and 98%, and the relationship between the number of hammer blows of the light dynamic probe at a depth of 10 cm in the soil and the compaction degree is obtained; the specific method is: artificially set piles with different compaction degrees at the construction site, obtain the compaction degrees in different intervals, and at the same time select no less than 30 groups of hammer blows and compaction degrees of the light dynamic probe at a depth of 10 cm in the soil as basic data for curve regression.
[0006] Preferably, the light dynamic penetration test uses a light cone dynamic penetration instrument, which has a scale of 10 to 20 cm marked during the test phase and a graduation value of 0.5 cm.
[0007] Preferably, a compaction test by sand filling method and a light dynamic penetration test at a corresponding position are carried out on the top of the newly formed cement soil compaction pile, and then regression statistics of the compaction degree and the number of light penetration hammer blows are performed; the corresponding position is: digging a pit and filling sand at a position 1 / 3 to 1 / 2 from the pile end to the center, and after taking out the sand in the pit, a light dynamic penetration test is carried out at the pile-soil interface on the other side of the same plane.
[0008] Preferably, a curve regression is performed with the number of hammer blows at a set depth into the soil as the x-axis and the degree of compaction as the y-axis, and first-order, second-order and third-order curve regressions are performed in sequence. The Nth-order equation of regression statistics is obtained based on the correlation, and then the compaction quality of the cement soil compaction pile is quickly obtained using the light cone dynamic probing method.
[0009] Preferably, before step one, it also includes: carrying out a compaction test by the sand injection method at different positions of the pile end, and at the same time, by setting the number of light penetration hammer blows or the depth of penetration into the soil at the corresponding position, counting the corresponding compaction and the depth of penetration into the soil for a fixed number of light penetration hammer blows or the number of hammer blows when penetrating into the set depth; regressing the obtained depth of penetration into the soil of the light penetration hammer blows and the compaction to determine whether they are correlated until the accuracy requirements are met; or determining whether the number of hammer blows when penetrating into the set depth is within the set range, and whether the soil is normal; thereby obtaining the depth of penetration into the soil for a fixed number of hammer blows or the number of hammer blows at a fixed depth corresponding to the light dynamic penetration test in step one.
[0010] Preferably, when the compaction degree obtained is between 93% and 98%, the number of hammer blows is between 35 and 95, and the light penetration test time of a single pile is 3 to 6 minutes, meeting the requirements for rapid detection.
[0011] Preferably, a verification method of the regression curve equation is also included between step 2 and step 3, specifically: the top of the completed compaction pile is flattened to expose the pile head, a light dynamic probing test is performed at the pile-soil interface on the end face of the single pile, and the number of hammer blows is recorded, so as to calculate the compaction degree according to the regression curve equation; a compaction test of the pit digging and sand filling method is performed at a position 1 / 3 to 1 / 2 away from the center of the pile on the other side of the same plane, and the compaction degree of the tested pile body is recorded, and at least 6 sets of data are verified in total; then, it is determined whether the error between the calculated compaction degree and the measured compaction degree is within a set range.
[0012] The present invention has at least the following beneficial effects: 1. The method of the present invention can quickly determine the compaction quality of special roadbed. Through rapid detection, the detection efficiency is improved, and it can avoid the long-term occupation of the construction work surface due to the detection work, thereby accelerating the construction progress.
[0013] 2. The method of the present invention not only improves the detection efficiency, but also achieves maximum savings and optimization of compaction instruments and material preparation, without the need to carry small tools such as sand measuring tools, sand filling tubes, and electronic balances multiple times.
[0014] 3. The method of the present invention is suitable for determining the compaction coefficient of 15% cement soil compaction piles in special roadbeds in collapsible loess areas; the calibrated regression method and test method can also be used for compaction quality detection of other similar fine-grained soil roadbed fillers.
[0015] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the on-site sand filling method detection of the present invention; Figure 2 This is a schematic diagram of an on-site light dynamic penetration test of the present invention; Figure 3 It is a schematic diagram of a light cone dynamic penetration instrument with scale according to the present invention; Figure 4 This is the Nth curve diagram of the correlation between the number of penetration hammer blows and the degree of compaction of the present invention. DETAILED DESCRIPTION
[0017] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.
[0018] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0019] like Figures 1 to 3 As shown, the present invention provides a method for quickly detecting the compaction quality of a special roadbed, comprising the following steps: Step 1: Collect the soil penetration depth of fixed number of hammer strikes or the number of hammer strikes at fixed depth of soil penetration corresponding to the compaction degree of sand filling method and light dynamic penetration test for the same material, the same construction process, the same site and construction location; Before step one, it also includes: carrying out a compaction test by the sand injection method at different positions of the pile end, and at the same time, by setting the number of light penetration hammer blows or the depth of penetration into the soil at the corresponding position, counting the corresponding compaction and the depth of penetration into the soil for a fixed number of light penetration hammer blows or the number of hammer blows when penetrating into the set depth; regressing the obtained depth of penetration into the soil of the light penetration hammer blows and the compaction to determine whether they are correlated until the accuracy requirements are met; or determining whether the number of hammer blows when penetrating into the set depth is within the set range, and whether the soil is normal; thereby obtaining the depth of penetration into the soil for a fixed number of hammer blows or the number of hammer blows at a fixed depth corresponding to the light dynamic penetration test in step one.
[0020] Step 2: Comprehensively analyze the collected data pairs, and make N-time curve regressions with the compaction degree of the sand filling method and the light dynamic penetration test data to obtain the regression curve equation of the compaction degree; The compaction degree measured by the on-site sand filling method is between 93% and 98%, and the relationship between the number of hammer strikes of the light dynamic penetration test at a depth of 10 cm and the compaction degree is obtained; the specific method is: artificially set piles with different compaction degrees at the construction site to obtain compaction degrees in different intervals, and at the same time select no less than 30 groups of hammer strikes and compaction degrees of the light dynamic penetration test at a depth of 10 cm as basic data for curve regression. When the compaction degree obtained is between 93% and 98%, the number of hammer strikes is between 35 and 95, and the light penetration test time of a single pile is 3 to 6 minutes, which meets the requirements of rapid detection.
[0021] It also includes a verification method for the regression curve equation, specifically: flatten the top of the completed compaction pile to expose the pile head, conduct a light dynamic probing test at the pile-soil interface at the end face of the single pile, record the number of hammer blows, and calculate the compaction degree based on the regression curve equation; conduct a compaction test using the pit digging and sand filling method at a position 1 / 3 to 1 / 2 away from the center of the pile on the other side of the same plane, record the compaction degree of the tested pile body, and verify at least 6 sets of data in total; then determine whether the error between the calculated compaction degree and the measured compaction degree is within the set range.
[0022] Step 3: Perform a quick test of compaction quality based on the regression curve equation.
[0023] The characteristics of the light dynamic penetration test method in special roadbed compaction quality testing activities are as follows: Scope of application: Applicable to gravel soil, sandy soil, clay soil, and can be used to evaluate the density of foundation soil and determine the deformation modulus and bearing capacity of foundation soil.
[0024] Basic principle: A standard probe connected to a probe rod is driven into the soil, and the mechanical properties of the soil are determined by the number of hammer strikes required when the probe penetrates a certain depth into the soil, thereby evaluating the compaction quality of the filler.
[0025] Instruments and tools: The new method of this application only uses a light cone dynamic probe, while the old method uses a Φ150 sand filling cylinder, sand measuring machine, electronic balance, oven, auxiliary tools, etc.
[0026] Probe rod scale: In order to accurately perform statistical regression, the scale is marked with 10~20cm during the test phase, with a graduation value of 0.5cm.
[0027] According to the above theory, a compaction test of the sand filling method and a light dynamic penetration test at the corresponding position were carried out on the top of the newly formed 15% cement soil compaction pile, and regression statistics of compaction and light penetration hammer number were carried out; the corresponding position is: digging a pit and filling sand at a position 1 / 3~1 / 2 from the pile end to the center, and after taking out the sand in the pit, a light dynamic penetration test was carried out at the pile-soil interface on the other side of the same plane. With the number of hammers penetrating a certain depth as the x-axis and the compaction as the y-axis, the first curve, the second curve, and the third curve regression were carried out in turn, and the Nth-order equation of regression statistics was obtained according to the correlation, and then used for the on-site light penetration test. Combined with the Nth-order equation, the compaction quality of the cement soil compaction pile can be quickly obtained by using the light cone dynamic penetration method.
[0028] Using the detection method described in the method of the present invention, data processing and analysis are performed on the basis of a large number of statistical sand filling tests and light dynamic penetration tests, and an approximate compaction degree evaluation formula is obtained by regression. The method has a fast detection speed and is easy to operate. In the process of implementing the detection example, through corresponding verification, the ideal detection reliability is achieved, and the purpose of quickly and accurately knowing the compaction quality of the special roadbed can be achieved. Example 1 A special roadbed compaction quality rapid detection method, the operation method is: after the top of the selected cement soil compaction pile to be tested is leveled, the compaction test is carried out at the center of the pile end by sand filling method, the sand in the pit is taken out after sand filling, and a dynamic penetration test is carried out at the center of the pit bottom with a light penetration instrument. The statistical data includes: compaction degree, soil penetration depth when the light penetration test is 50 hits, as shown in Table 1 below. The graduation value of the scale marked at the lower end of the probe rod is 0.5cm.
[0029] Table 1 Test data statistics (pile body 50 hits) In this example, the penetration depth of the light penetration hammer with 50 hits is too shallow, and the accuracy of the regression between the obtained penetration depth and compaction degree does not meet the requirements. Moreover, after the bottom of the pit is penetrated, the scale of the probe rod is not perpendicular to the viewing angle, and it cannot be accurately measured.
[0030] Example 2 A special roadbed compaction quality rapid detection method, the operation method is: after the top of the selected cement soil compaction pile to be tested is flattened, a pit is dug and filled with sand at a position about 1 / 3 to 1 / 2 from the pile end to the center, and after the sand in the pit is taken out, a light cone dynamic penetration test is performed at a position 1 / 3 to 1 / 2 from the pile center on the other side of the same plane. The statistical data includes: compaction degree, the number of hammer blows when the light penetration test penetrates 10 cm, as shown in Table 2 below. The graduation value of the scale marked at the lower end of the probe rod is 0.5 cm, so that the measured data can be read more accurately.
[0031] Table 2 Test data statistics (pile body 10cm) In this example, the number of hammer blows when the light penetration was 10 cm was too large, and the test time was too long, which did not meet the research and development goals of the rapid test. In addition, the sand filling pit was close to the penetration point, and the soil around the penetration point was broken during the test. The number of hammer blows was inaccurate, and the associated regression curve could not be obtained normally.
[0032] Example 3 A special roadbed compaction quality rapid detection method, the operation method is: after leveling the top of the selected cement soil compaction pile to be tested, dig a pit and fill it with sand at a position about 1 / 3 to 1 / 2 from the pile end to the center, take out the sand in the pit, and then conduct a light cone dynamic penetration test at the pile-soil interface on the other side of the same plane. The statistical data includes: compaction degree, the number of hammer blows when the light penetration test is 10cm, as shown in Table 3 below. The graduation value of the scale marked at the lower end of the probe rod is 0.5cm, so that the measured data can be read more accurately.
[0033] Table 3 Test data statistics (10cm at the pile-soil interface) In this example, the number of hammer blows when the light penetration is 10 cm is related to the compaction degree. When the compaction degree is between 93% and 98%, the number of hammer blows is approximately between 35 and 95, and the detection time is about 3 to 6 minutes, which meets the requirements of rapid detection.
[0034] Example 4 A special roadbed compaction quality rapid detection method, the operation method is: in order to count the number of light penetration hammer blows between 93% and 98% of compaction degree, piles with different compaction degrees are set artificially at the construction site. Using the construction machinery clamp hammer, the time setting when compacting the filler is used to obtain the compaction degree in different intervals. 30 sets of basic data are selected for regression. After leveling the top of the selected cement soil compaction pile to be inspected, a pit is dug and filled with sand at a position about 1 / 3 to 1 / 2 from the center of the pile end. After taking out the measured sand in the pit, a light cone dynamic penetration test is performed at the pile-soil interface on the other side of the same plane. The statistical data includes: compaction degree, the number of hammer blows when the light penetration test penetrates 10 cm, as shown in Table 4 below. The graduation value of the scale marked at the lower end of the probe rod is 0.5 cm, so that the measured data can be read more accurately.
[0035] Table 4 Statistics of compaction degree and penetration hammer blows (30 groups) In this example, in order to obtain the correlation between the number of hammer blows and the degree of compaction when the light penetration is 10 cm, 30 sets of data were collected. When the degree of compaction is between 93% and 98%, the number of hammer blows is approximately between 35 and 95. The light penetration test time of a single pile is about 3 to 6 minutes, which meets the requirements of rapid detection. When using Example 4 for curve regression, when using a linear curve, the correlation R is less than 0.95, when using a quadratic curve, the correlation R is greater than 0.95, and when using a cubic curve or above, the correlation is closer to 1.00. Because the regression equation obtained in this example can meet the needs of on-site detection using a quadratic curve, the regression quadratic curve is as follows: Figure 4 shown.
[0036] Example 5 A special roadbed compaction quality rapid detection method, the verification operation method is: the top of the completed compaction pile is flattened to expose the pile head, and a light dynamic penetration test is performed at the pile-soil interface on the end face of the single pile. The number of hammer blows is recorded, and a compaction test of the pit digging and sand filling method is performed at a position about 1 / 3 to 1 / 2 away from the center of the pile on the other side of the same plane. The compaction of the tested pile body is recorded, and a total of 6 sets of data are verified, as shown in Table 5 below.
[0037] Table 5 Field verification record of compaction quality rapid detection method The above examples show that the light penetration test is feasible in the rapid detection of special roadbeds. Through verification, the fluctuation range between the calculated compaction degree and the measured compaction degree is small, which can meet the requirements of rapid detection to a certain extent. It has good economic benefits.
[0038] Since the soil between the compacted piles has been squeezed twice by punching holes and filling with mixed materials, a relatively dense and uniform soil layer has been formed. The dense soil layer is in close contact with the pile body, which can fully form a bearing capacity sufficient for detection and measurement. Therefore, this method can obtain a measurable regression interval.
[0039] The instruments and consumables used in the present invention are calibrated on schedule, and the operators hold the highway test and inspection certificate of the Ministry of Communications.
[0040] The filler used in the present invention is the relative bearing capacity concept obtained by mixing 15% cement with silt in the hilly area of Mangling in Northwest China. When used in different fine soil areas, 30 sets of data regression must be performed before use. The method can be used to quickly detect the compaction quality, which can save detection time, is simple to operate, does not require the loss of a large amount of sand material, and does not require a long waiting time for the moisture content test to calculate the compaction degree.
[0041] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily implemented, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.
Claims
1. A method for rapid detection of special roadbed compaction quality, characterized in that: The steps include: Step 1: Collect the soil penetration depth of fixed number of hammer strikes or the number of hammer strikes at fixed depth of soil penetration corresponding to the compaction degree of sand filling method and light dynamic penetration test for the same material, the same construction process, the same site and construction location; Step 2: Comprehensively analyze the collected data pairs, and make N-time curve regressions with the compaction degree of the sand filling method and the light dynamic penetration test data to obtain the regression curve equation of the compaction degree; Step 3: Perform a quick test of compaction quality based on the regression curve equation.
2. The special roadbed compaction quality rapid detection method according to claim 1, characterized in that: The compaction degree measured by the on-site sand injection method is between 93% and 98%, and the relationship between the number of hammer blows of the light dynamic penetration test at a depth of 10 cm and the compaction degree is obtained; the specific method is: piles with different compaction degrees are artificially set at the construction site to obtain the compaction degrees in different intervals, and at the same time, no less than 30 groups of hammer blows and compaction degrees of the light dynamic penetration test at a depth of 10 cm are selected as basic data for curve regression.
3. The special roadbed compaction quality rapid detection method according to claim 1, characterized in that: The light dynamic penetration test uses a light cone dynamic penetration instrument, which has a marking scale of 10~20cm and a graduation value of 0.5cm during the test phase.
4. The special roadbed compaction quality rapid detection method according to claim 1, characterized in that: A compaction test using the sand filling method and a light dynamic penetration test were carried out on the top of the newly formed cement-soil compaction pile, and then a regression statistics of the compaction degree and the number of light penetration hammer blows was performed; the corresponding positions were: a pit was dug and sand was filled at a position 1 / 3 to 1 / 2 from the pile end to the center, and after taking out the sand in the pit, a light dynamic penetration test was carried out at the pile-soil interface on the other side of the same plane.
5. The special roadbed compaction quality rapid detection method according to claim 2, characterized in that: The number of hammer blows at the set depth of soil is taken as the x-axis, and the compaction degree is taken as the y-axis for curve regression. The first, second and third curve regressions are performed in sequence. The Nth order equation of regression statistics is obtained according to the correlation, and then the compaction quality of the cement soil compaction pile is quickly obtained by the light cone dynamic penetration method.
6. The special roadbed compaction quality rapid detection method according to claim 1, characterized in that: Prior to step one, the method also includes: performing a compaction test using the sand injection method at different positions of the pile end, and at the same time setting the number of light penetration hammer blows or the depth of penetration into the soil at the corresponding position, and counting the corresponding compaction and the depth of penetration into the soil for a fixed number of light penetration hammer blows or the number of hammer blows when penetrating into the set depth; regressing the obtained depth of penetration into the soil of the light penetration hammer blows and the compaction to determine whether they are correlated until the accuracy requirements are met; or determining whether the number of hammer blows when penetrating into the set depth is within the set range, and whether the soil is normal; thereby obtaining the depth of penetration into the soil for a fixed number of hammer blows or the number of hammer blows at a fixed depth of penetration into the soil corresponding to the light dynamic penetration test in step one.
7. The special roadbed compaction quality rapid detection method according to claim 6, characterized in that: When the compaction degree obtained is between 93% and 98%, the number of hammer blows is between 35 and 95, and the light penetration test time of a single pile is 3 to 6 minutes, which meets the requirements of rapid detection.
8. The special roadbed compaction quality rapid detection method according to claim 1, characterized in that: The step 2 and the step 3 also include a verification method of the regression curve equation, which is specifically: flattening the top of the compaction pile after construction to expose the pile head, performing a light dynamic penetration test at the pile-soil interface of the single pile end face, recording the number of hammer blows, and calculating the compaction degree according to the regression curve equation; performing a compaction test of the pit digging and sand filling method at a position 1 / 3 to 1 / 2 away from the center of the pile on the other side of the same plane, recording the compaction degree of the tested pile body, and verifying at least 6 sets of data in total; Then determine whether the error between the calculated compaction degree and the measured compaction degree is within the set range.