Method for detecting compaction degree of sand-filled roadbed by pre-embedding correction large-ring cutter method

Abstract

The invention discloses a method for detecting the compaction degree of a sand-filled roadbed by an embedded correction large-ring cutter method, and belongs to the technical field of compaction degree detection. The method comprises the following steps that S2, a road roller is started, rolling is conducted according to set compaction parameters, and the number of rolling times is counted as one round trip; s3, after each time of rolling is completed, randomly selecting two detection sections, digging out a pre-embedded correction cutting ring, aligning the top of the correction cutting ring, smoothing the sand sample, wiping the outer wall of the correction cutting ring, and weighing the total mass of the correction cutting ring and the sand until the precision is 0.1 g; and S4, after weighing is completed, part of the sand sample is taken from the center of the sand sample, the water content is measured, the wet density, the dry density and the compaction degree of a detection point are calculated, and the water content is accurate to 0.1%. The method is suitable for testing the density of the coastal sand roadbed on site and calculating the construction compactness so as to evaluate the compaction quality of the coastal sand roadbed.

Description

Technical Field

[0001] The invention relates to the technical field of compaction detection, and in particular to a compaction detection method for a sand-filled roadbed pre-buried correction large-ring knife method. Background Art

[0002] Coarse sand, medium sand, fine sand and silt (collectively referred to as coastal sand) are widely distributed in the coastal areas of Hainan. Coastal sand has the characteristics of loose structure, single particle size, difficult compaction, poor overall compaction, and easy to be washed away by water. Its special performance makes it a poor material for roadbed filling. At present, the construction of green highways is steadily advancing, and the highway construction concept of "less borrowing and zero abandonment" has become an inevitable requirement. It is inevitable that a large amount of coastal sand will be used to fill the roadbed. The compaction quality inspection during the construction process is the key to ensuring the compaction quality of the roadbed.

[0003] Compaction is a key indicator for quality inspection of fill roadbed construction. However, due to the non-stickiness, looseness and single particle size of coastal sand, the traditional sand filling method is very prone to hole collapse and cannot accurately test the compaction. The indoor compaction test is a test method under lateral rigid constraint conditions. The use of a matching field test method can better reflect the compaction quality of coastal sand and is more in line with engineering practice. Therefore, it is urgent to propose a method for testing the compaction of sand-filled roadbed. Summary of the invention

[0004] The invention aims to provide a compaction detection method for a sand-filled roadbed pre-buried correction large-ring knife method. The method is suitable for on-site testing of the density of a coastal sand roadbed and calculating the construction compaction degree to evaluate the compaction quality of the coastal sand roadbed.

[0005] In order to achieve the purpose of the above invention, the present invention adopts the following technical solution:

[0006] A method for detecting the compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method comprises the following steps:

[0007] S1. Select a test section and do preparatory work on the test section before compaction test. After the preparatory work is completed, park the roller in front of the test section.

[0008] S2. Start the roller and perform rolling according to the established compaction process parameters. One round trip is counted as one pass.

[0009] S3. After each rolling, randomly select 2 test sections, dig out the embedded correction ring cutter, carefully flatten the sand sample even with the top of the correction ring cutter, wipe the outer wall of the correction ring cutter, and weigh the total mass m2 of the correction ring cutter and sand, accurate to 0.1g;

[0010] S4. After weighing, take part of the sand sample from the center of the sand sample to measure the moisture content, and calculate the wet density, dry density and compaction degree of the test point, where the moisture content is accurate to 0.1%;

[0011] S5, repeating steps S2 to S4 until there are no obvious rolling wheel marks on the test road section, and the rolling test is completed;

[0012] S6. Organize the results, use compaction degree as the vertical coordinate and the number of rolling times as the horizontal coordinate, draw a curve of the relationship between compaction degree and the number of rolling times, and determine the number of rolling times.

[0013] Furthermore, the preparation work before the compaction test in step S1 includes the following steps:

[0014] S11, setting up multiple detection sections at intervals along the longitudinal direction of the selected road section, wherein poles are inserted and colorful flags are hung on the outer sides of the earth roadbed on the left and right sides of each detection section;

[0015] S12. Test points are arranged at the center of the left lane, the center of the right lane, and the center of the road of each test section. Two correction ring knives are embedded in each test point, and the mass m1 of the correction ring knives is weighed with an accuracy of 0.1g;

[0016] S13. Use RTK to record the coordinates of the detection points, and mark them by spraying red paint and burying colored strips.

[0017] Furthermore, in step S11, the distance between the detection sections is 10m, and the number of the detection sections is not less than 20;

[0018] The buried depth of the bottom of the correction ring cutter in step S12 is 20 to 30 cm.

[0019] Furthermore, the calculation method of the wet density of the detection point in step S4 is:

[0020]

[0021] Where ρ is the wet density of the sand at the test point g / cm 3 ; m1 is the mass of the correction ring cutter g; m2 is the total mass of the correction ring cutter and wet sand g; V is the volume of the correction ring cutter cm 3 .

[0022] Furthermore, the calculation method of the dry density of the detection point in step S4 is:

[0023]

[0024] Among them, ρ d The dry density of the sand at the test point is g / cm 3 ;ω: moisture content of sand at detection point%.

[0025] Furthermore, the method for calculating the compaction degree of the detection point in step S4 is:

[0026]

[0027] Where K is the compaction degree of the sand at the test point; ρ max Maximum dry density of sand at the test point g / cm 3 .

[0028] Furthermore, the sand at the test point was compacted with the same material to obtain the maximum dry density ρ max And the optimal moisture content ω.

[0029] Furthermore, the correction ring knife is a cylinder without a top, with an inner diameter of 10 cm, a height of 12.7 cm, a wall thickness of 3 mm to 5 mm, and a volume of 997 cm 3 .

[0030] Beneficial effects: This method is suitable for on-site testing of the density of coastal sand roadbed and calculating the construction compaction degree to evaluate the compaction quality of coastal sand roadbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a correction ring knife in a compaction degree detection method of a sand-filled roadbed pre-buried correction large ring knife method proposed by the present invention;

[0032] In the figure: 1. Correct the ring cutter. DETAILED DESCRIPTION

[0033] Example 1

[0034] A method for detecting the compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method comprises the following steps:

[0035] S1. Select a test section and do preparatory work on the test section before compaction test. After the preparatory work is completed, park the roller in front of the test section. Among them, select a section with representative geological conditions, roadbed section form, etc. as the test section, and do preparatory work such as loading, paving, leveling, and pre-embedding correction ring cutter on the test section before compaction test;

[0036] S2. Start the roller and perform rolling according to the established compaction parameters. One round trip is counted as one pass.

[0037] S3. After each rolling, randomly select 2 test sections, dig out the embedded correction ring cutter 1, carefully flatten the sand sample even with the top of the correction ring cutter, wipe the outer wall of the ring cutter, and weigh the total mass m2 of the correction ring cutter 1 and the sand, accurate to 0.1g;

[0038] S4. After weighing, take part of the sand sample from the center of the sand sample to measure the moisture content, and calculate the wet density, dry density and compaction degree of the test point, where the moisture content is accurate to 0.1%;

[0039] S5, repeating steps S2 to S4 until there are no obvious rolling wheel marks on the test road section, and the rolling test is completed;

[0040] S6. Organize the results, use compaction degree as the vertical coordinate and the number of rolling times as the horizontal coordinate, draw a curve of the relationship between compaction degree and the number of rolling times, and determine the number of rolling times.

[0041] In this embodiment, the selected test section is selected according to the requirements of JTG / T3610 "Technical Specifications for Highway Roadbed Construction".

[0042] In this embodiment, the roller is parked 20 m in front of the test section.

[0043] In this embodiment, the point on the curve where the compaction degree tends to be stable and meets the compaction degree control standard of the corresponding part, the corresponding horizontal coordinate is the number of rolling times suitable for the coastal sand roadbed.

[0044] Preferably, the preparation work before the compaction degree detection in step S1 includes the following steps:

[0045] S11, setting up multiple detection sections at intervals along the longitudinal direction of the selected road section, wherein poles are inserted and colorful flags are hung on the outer sides of the earth roadbed on the left and right sides of each detection section;

[0046] S12. Test points are arranged at the center of the left lane, the center of the right lane and the center of the road of each test section. Two correction ring knives 1 are pre-buried at each test point, and the mass m1 of the correction ring knife 1 is weighed with an accuracy of 0.1g;

[0047] S13. Use RTK to record the coordinates of the detection points, and mark them by spraying red paint and burying colored strips.

[0048] Preferably, in step S11, the distance between the detection sections is 10m, and the number of the detection sections is not less than 20;

[0049] The buried depth of the bottom of the correction ring cutter 1 in step S12 is 20 to 30 cm.

[0050] Preferably, the calculation method of the wet density of the detection point in step S4 is:

[0051]

[0052] Where ρ is the wet density of the sand at the test point g / cm 3 ; m1 is the mass of the correction ring cutter 1 in g; m2 is the total mass of the correction ring cutter 1 and the wet sand in g; V is the volume of the correction ring cutter 1 in cm 3 .

[0053] Preferably, the calculation method of the dry density of the detection point in step S4 is:

[0054]

[0055] Among them, ρ d The dry density of the sand at the test point is g / cm 3 ;ω: moisture content of sand at detection point%.

[0056] Preferably, the method for calculating the compaction degree of the detection point in step S4 is:

[0057]

[0058] Where K is the compaction degree of the sand at the test point; ρ max Maximum dry density of sand at the test point g / cm 3 .

[0059] Preferably, a compaction test is performed on the sand at the detection point using the same material to obtain the maximum dry density ρ max And the optimal moisture content ω.

[0060] In this embodiment, a compaction test is performed on the sand at the detection point using the same material according to the method specified in JTG 3430 compaction test (T0131-2019).

[0061] Preferably, the correction ring knife 1 is a cylinder without a top, with an inner diameter of 10 cm, a height of 12.7 cm, a wall thickness of 3 mm to 5 mm, and a volume of 997 cm 3 .

[0062] In this embodiment, it also includes an electronic scale, a small shovel, a soil knife, a brush, a ruler, a wire saw and a moisture content testing device, among which the electronic scale has a weighing capacity of 2000g and a sensitivity of 0.01g; a weighing capacity of 10kg and a sensitivity of 1g.

[0063] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for testing the compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method, characterized in that: The steps include: S1. Select a test section and do preparatory work on the test section before compaction test. After the preparatory work is completed, park the roller in front of the test section. S2. Start the roller and perform rolling according to the established compaction process parameters. One round trip is counted as one pass. S3. After each rolling, randomly select 2 test sections, dig out the embedded correction ring cutter, carefully flatten the sand sample even with the top of the correction ring cutter, wipe the outer wall of the correction ring cutter, and weigh the total mass m2 of the correction ring cutter and sand, accurate to 0.1g; S4. After weighing, take part of the sand sample from the center of the sand sample to measure the moisture content, and calculate the wet density, dry density and compaction degree of the test point, where the moisture content is accurate to 0.1%; S5, repeating steps S2 to S4 until there are no obvious rolling wheel marks on the test road section, and the rolling test is completed; S6. Organize the results, use compaction degree as the vertical coordinate and the number of rolling times as the horizontal coordinate, draw a curve of the relationship between compaction degree and the number of rolling times, and determine the number of rolling times.

2. A method for detecting compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 1, characterized in that: The preparation work before the compaction test in step S1 includes the following steps: S11, setting up multiple detection sections at intervals along the longitudinal direction of the selected road section, wherein poles are inserted and colorful flags are hung on the outer sides of the earth roadbed on the left and right sides of each detection section; S12. Test points are arranged at the center of the left lane, the center of the right lane, and the center of the road in each test section. Two correction ring knives are embedded in each test point, and the mass m1 of the correction ring knives is weighed with an accuracy of 0.1g; S13. Use RTK to record the coordinates of the detection points, and mark them by spraying red paint and burying colored strips.

3. A method for detecting compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 2, characterized in that: In step S11, the distance between the detection sections is 10m, and the number of detection sections is not less than 20; The buried depth of the bottom of the correction ring cutter in step S12 is 20 to 30 cm.

4. A method for detecting compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 2, characterized in that: The calculation method of the wet density of the detection point in step S4 is: Where ρ is the wet density of the sand at the test point g / cm 3 ; m1 is the mass of the correction ring cutter g; m2 is the total mass of the correction ring cutter and wet sand g; V is the volume of the correction ring cutter cm 3 .

5. A method for detecting compaction degree of sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 4, characterized in that: The calculation method of the dry density of the detection point in step S4 is: Among them, ρ d The dry density of the sand at the test point is g / cm 3 ;ω: moisture content of sand at detection point %.

6. A method for detecting the compaction degree of a sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 5, characterized in that: The calculation method of the compaction degree of the detection point in step S4 is: Where K is the compaction degree of the sand at the test point; ρ max Maximum dry density of sand at the test point g / cm 3 .

7. A method for detecting compaction degree of sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 6, characterized in that: The compaction test is carried out on the sand at the test point with the same material to obtain the maximum dry density ρ max And the optimal moisture content ω.

8. A method for detecting compaction degree of sand-filled roadbed pre-embedded correction large ring knife method as claimed in claim 1, characterized in that: The correction ring knife is a cylinder without a top. The inner diameter of the correction ring knife is 10cm, the height is 12.7cm, the wall thickness is 3mm~5mm, and the volume is 997cm 3 .

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