A method for optimizing process parameters of underwater heavy hammer rock drilling

Abstract

The present invention aims to provide a method for optimizing underwater heavy hammer rock drilling process parameters, which simplifies the on-site process test process, combines indoor rock drop hammer test and numerical simulation test to quickly determine rock drilling process parameters, and effectively improves the underwater heavy hammer rock drilling efficiency. The present invention includes the following steps: selecting a corresponding type of rock hammer according to the bedrock type of the site; drilling a bedrock core sample of the site, and conducting a bedrock rock drop hammer test with different drop hammer speeds on the bedrock core sample; comparing the numerical value of the bedrock rock drop hammer test with the simulation calculation results, and inverting and generating bedrock rock constitutive model parameters; conducting rock hammer rock drilling test simulation calculations with different blade angles to determine the optimal rock hammer blade angle; determining the optimal drop hammer speed and the corresponding optimal drop hammer height through the ratio of the rock plastic damage volume to the square of the drop hammer speed; conducting single-point multiple rock drilling test simulation calculations to determine the optimal number of drops. The present invention is applied to the technical field of optimizing underwater heavy hammer rock drilling process parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of optimizing underwater heavy hammer rock drilling process parameters, and in particular to a method for optimizing underwater heavy hammer rock drilling process parameters. Background Art

[0002] Port expansion, channel dredging, and tunnel excavation often involve underwater rock breaking and reef clearing. Underwater mechanical rock drilling technology, which uses a grab dredger equipped with a rock hammer or rock bar to break the hard layer and then remove it with a grab ship, has the advantages of simple and economical equipment modification, rapid construction, flexible entry and exit, and high safety. It is widely used in rock breaking and reef clearing projects, especially in surrounding buildings (structures) and waters of importance for marine environmental protection.

[0003] At present, the methods for determining the process parameters of underwater mechanical rock drilling include subjective experience method and on-site process test method. The process parameters selected by the subjective experience method are mainly based on the previous experience and subjective judgment of engineers, which are often quite different from the actual requirements, often resulting in multiple reworks; the on-site process test method first presets several combinations of rock drilling process parameters based on previous experience, then selects a representative area of ​​the site for rock drilling tests, and finally uses the grab boat to measure the amount of reef clearance to judge the rationality of the rock drilling process parameters. Although the on-site process test method has high reliability, it is time-consuming and labor-intensive. It requires the test area to reach a certain range to facilitate the distinction of rock breaking effects under different rock drilling process parameters. However, due to the small number of underwater rock drilling construction cases and the difficulty of direct observation as a hidden project, the configuration of construction parameters lacks data support and is highly subjective. Therefore, there is an urgent need to provide a process parameter optimization method that can help determine the rock drilling construction parameters in a specific site. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for optimizing underwater heavy hammer rock drilling process parameters by simplifying the on-site process test process and combining indoor rock drop hammer test with numerical simulation test to quickly determine the rock drilling process parameters and effectively improve the underwater heavy hammer rock drilling efficiency.

[0005] The process parameter optimization method adopted in the technical solution of the present invention comprises the following steps:

[0006] S1. Select the appropriate type of rock hammer according to the bedrock type of the site;

[0007] S2. Drill bedrock core samples from the site, conduct bedrock rock drop hammer tests at different drop hammer speeds on the bedrock core samples, and record the bedrock rock drop hammer test values;

[0008] S3. Perform numerical simulation calculation of bedrock drop hammer based on the bedrock type and basic physical parameters of the site, compare the bedrock drop hammer test value with the simulation calculation results, and inversely generate bedrock constitutive model parameters;

[0009] S4. According to the parameters of the bedrock constitutive model and the selected rock hammer type, carry out rock drilling test simulation calculations with different blade angles to determine the optimal rock hammer blade angle θ r ;

[0010] S5. Based on the optimal rock hammer blade angle θ r Carry out simulation calculation of single-point single-shot rock drilling test, and determine the optimal drop hammer speed V through the ratio of rock plastic damage volume to the square of drop hammer speed r And the corresponding optimal drop height H r ;

[0011] S6. Based on the optimal rock hammer blade angle θ r and the optimal drop velocity V r And the optimal drop height H r , carry out simulation calculation of single-point multiple rock drilling test to determine the optimal number of hammer drops n r ;

[0012] S7, based on the optimal number of hammer drops n r The volume of rock plastic damage formed is used to calculate the equivalent radius of the rock plastic zone in single-point multiple rock drilling, determine the drilling point distance, and thus determine the underwater heavy hammer rock drilling process parameters.

[0013] Further, in step S1, a corresponding rock hammer type is selected, specifically by the following steps:

[0014] S1.1. Obtain the saturated uniaxial compressive strength and integrity of bedrock;

[0015] S1.2. Determine the bedrock type according to the saturated uniaxial compressive strength and integrity, and select the corresponding rock hammer.

[0016] Further, in step S4, the optimal rock hammer blade angle θ is determined r , specifically through the following steps:

[0017] S4.1. Setting a gradual increasing rock hammer blade angle;

[0018] S4.2. Carry out simulation calculation of rock drilling test at single point and single time with different rock hammer blade angles, and obtain the rock plastic damage volume under each rock hammer blade angle;

[0019] S4.3. With the rock hammer blade angle as the abscissa and the first rock plastic damage volume as the ordinate, a first curve is drawn. The rock hammer blade angle corresponding to the peak value of the first curve is the optimal rock hammer blade angle θ. r .

[0020] Further, in step S5, the optimal drop speed V is determined. r , specifically through the following steps:

[0021] S5.1. Setting a gradual increasing rock hammer drop speed;

[0022] S5.2. Carry out simulation calculation of single-point single-shot rock drilling test in water, test and record the corresponding rock plastic damage volume;

[0023] S5.3. Take the drop hammer speed as the horizontal coordinate and the ratio of the second rock plastic damage volume to the square of the drop hammer speed as the vertical coordinate to obtain the second curve. The drop hammer speed corresponding to the peak value of the second curve is the optimal drop hammer speed V r .

[0024] Further, in step S5, the optimal drop height H is determined. r The specific formula is:

[0025]

[0026] Among them, H r is the falling height, v r is the falling speed, g is the acceleration due to gravity, and S is the water depth.

[0027] Further, in step S6, the optimal number of hammer drops n is determined. r , specifically through the following steps:

[0028] S6.1. Carry out simulation calculation of single-point multiple drop hammer rock drilling test in water, test and record the number of drop hammers and the corresponding rock plastic damage volume;

[0029] S6.2. With the single-point hammer drop times as the horizontal coordinate and the ratio of the rock plastic damage volume to the hammer drop times as the vertical coordinate, a third curve is drawn. The peak value of the third curve corresponds to the hammer drop times, which is the optimal hammer drop times n. r .

[0030] Further, in step S7, the rock drilling point distance calculation formula is:

[0031]

[0032] Among them, R is the drilling point distance, ξ is the rock system coefficient, and V is the rock plastic damage volume.

[0033] The beneficial effects of the present invention are as follows: because the present invention sequentially carries out numerical tests on rock drilling with different rock hammer blade angle shapes, different drop hammer heights, different rock hammer masses, single-point multiple rock drilling and different rock drilling point distances, a curve of rock plastic damage volume changing with blade angle shape, drop hammer height, rock hammer mass and rock drilling times is drawn, and then the optimized rock drilling height, rock hammer mass, single-point rock drilling times and rock drilling point distance are given, the on-site process test process is simplified, and the rock drilling process parameters can be quickly determined by rock drilling tests at only a few points, which can effectively improve the efficiency and intelligence level of underwater heavy hammer rock drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the process of the present invention;

[0035] Figure 2 is a curve showing the change of the rock plastic damage volume with the rock hammer blade angle according to the present invention;

[0036] Figure 3 is the curve of the change of the rock plastic damage volume with the square of the drop weight velocity in the present invention;

[0037] Figure 4 This is the curve of the change of rock plastic damage volume with the number of hammer drops in the present invention. DETAILED DESCRIPTION

[0038] like Figures 1 to 4 As shown, in this embodiment, the process parameter optimization method of the present invention includes the following steps:

[0039] S1. Select the appropriate type of rock hammer according to the bedrock type of the site;

[0040] S2. Drill bedrock core samples from the site, conduct bedrock rock drop hammer tests at different drop hammer speeds on the bedrock core samples, and record the bedrock rock drop hammer test values;

[0041] S3. Perform numerical simulation calculation of bedrock drop hammer based on the bedrock type and basic physical parameters of the site, compare the bedrock drop hammer test value with the simulation calculation results, and inversely generate bedrock constitutive model parameters;

[0042] S4. According to the parameters of the bedrock constitutive model and the selected rock hammer type, carry out rock drilling test simulation calculations with different blade angles to determine the optimal rock hammer blade angle θ r ;

[0043] S5. Based on the optimal rock hammer blade angle θ r Carry out simulation calculation of single-point single-shot rock drilling test, and determine the optimal drop hammer speed V through the ratio of rock plastic damage volume to the square of drop hammer speed r And the corresponding optimal drop height H r ;

[0044] S6. Based on the optimal rock hammer blade angle θ r and the optimal drop velocity V r And the optimal drop height H r , carry out simulation calculation of single-point multiple rock drilling test to determine the optimal number of hammer drops n r ;

[0045] S7, based on the optimal number of hammer drops n rThe formed rock plastic damage volume is used to calculate the equivalent radius of the rock plastic zone of single-point multiple rock drilling, and the drilling point distance is determined, thereby determining the underwater heavy hammer rock drilling process parameters;

[0046] In step S2, the diameter of the drilled bedrock core sample is 75 mm. The rock sample used for the bedrock rock drop hammer test is a cylinder with a diameter of 75 mm and a height of 50 mm. The drop hammer used for the drop hammer test is divided into two types: axe type and pencil type according to the selected rock hammer type, and the material is cast iron;

[0047] The axe-shaped rock hammer has a drop hammer blade angle of 30°, a blade arc radius of 0.5 cm, a blade width of 4 cm, and a drop hammer rod height of 5 cm.

[0048] The pencil-type rock hammer has a drop hammer blade angle of 30°, a blade arc radius of 0.5 cm, a diameter of 3 cm, and a drop hammer rod height of 5 cm;

[0049] At the same time, in step S2, the drop hammer height is 2m, and the curve of the drop hammer penetration depth changing with time is recorded synchronously.

[0050] In this embodiment, in step S1, a corresponding rock hammer type is selected, specifically by the following steps:

[0051] S1.1. Obtain the saturated uniaxial compressive strength and integrity of bedrock;

[0052] S1.2. Determine the bedrock type according to the saturated uniaxial compressive strength and integrity, and select the corresponding rock hammer;

[0053] In step S1.1, the bedrock type is divided into soft rock, relatively hard rock and hard rock according to the saturated uniaxial compressive strength and integrity, corresponding to three types of rock hammers, namely light pencil-type rock hammer (hammer weight is less than 15 tons), heavy pencil-type rock hammer (hammer weight is between 15 tons and 30 tons) and axe-type rock hammer (hammer weight is greater than 30 tons); specifically, bedrock with a saturated uniaxial compressive strength lower than 15 MPa and a relatively broken or less rock integrity is classified as soft rock, and a light pencil-type rock hammer is selected; bedrock with a saturated uniaxial compressive strength lower than 15 MPa and a relatively intact or complete rock integrity is classified as relatively hard rock, and a heavy pencil-type rock hammer is selected; bedrock with a saturated uniaxial compressive strength higher than 15 MPa and a relatively intact or complete rock is classified as hard rock, and an axe-type rock hammer is selected.

[0054] In this embodiment, in step S4, the optimal rock hammer blade angle θ is determined. r Specifically through the following steps:

[0055] S4.1. Setting a gradual increasing rock hammer blade angle;

[0056] S4.2. Carry out simulation calculation of rock drilling test at single point and single time with different rock hammer blade angles, and obtain the rock plastic damage volume under each rock hammer blade angle;

[0057] S4.3. With the rock hammer blade angle as the abscissa and the first rock plastic damage volume as the ordinate, a first curve is drawn. The rock hammer blade angle corresponding to the peak value of the first curve is the optimal rock hammer blade angle θ. r ;

[0058] In step S4.1, a rock mass with a length, width and height of 10m×10m×4m is selected as the rock drilling numerical test model. The drop hammer speed is 15m / s, the drop hammer mass is 15t, and the rock drilling hammer blade angles are selected as 20°, 22°, 24°, 26°, 28°, 30°, 32°, 34°, 36°, 38° and 40° respectively.

[0059] In this embodiment, in step S5, the optimal drop speed V is determined. r Specifically through the following steps:

[0060] S5.1. Setting a gradual increasing rock hammer drop speed;

[0061] S5.2. Carry out simulation calculation of single-point single-shot rock drilling test in water, test and record the corresponding rock plastic damage volume;

[0062] S5.3. Take the drop hammer speed as the horizontal coordinate and the ratio of the second rock plastic damage volume to the square of the drop hammer speed as the vertical coordinate to obtain the second curve. The drop hammer speed corresponding to the peak value of the second curve is the optimal drop hammer speed V r ;

[0063] In step S5, a rock mass with a length, width and height of 10m×10m×4m is selected as a rock drilling numerical test model, and the formula for the reference drop hammer velocity in water is:

[0064]

[0065] Among them, V B is the falling weight velocity, S is the water depth, and g is the gravitational acceleration;

[0066] Drop weight speed V B The increasing gradient is

[0067] In this embodiment, in step S5, the optimal drop height H is determined. r The specific formula is:

[0068]

[0069] Among them, H r is the falling height, v ris the falling speed, g is the acceleration due to gravity, and S is the water depth.

[0070] In this embodiment, in step S6, the optimal number of hammer drops n is determined. r Specifically through the following steps:

[0071] S6.1. Carry out simulation calculation of single-point multiple drop hammer rock drilling test in water, test and record the number of drop hammers and the corresponding rock plastic damage volume;

[0072] S6.2. With the single-point hammer drop times as the horizontal coordinate and the ratio of the rock plastic damage volume to the hammer drop times as the vertical coordinate, a third curve is drawn. The peak value of the third curve corresponds to the hammer drop times, which is the optimal hammer drop times n. r ;

[0073] The rock mass was selected to carry out single-point multiple-drop hammer rock drilling numerical tests, and the curve of rock plastic damage volume changing with the number of drop hammers was plotted to determine the optimal number of drop hammers n for rock damage depth within the range of 30-50 cm. r , the calculation formula of rock damage depth is:

[0074]

[0075] Where R is the rock damage depth, and V is the rock plastic damage volume.

[0076] In this embodiment, in step S7, the rock drilling point distance calculation formula is:

[0077]

[0078] Among them, R is the drilling point distance, ξ is the rock system number, V is the rock plastic damage volume, the soft rock coefficient ξ = 0.5, the relatively soft rock ξ = 0.75, and the hard rock ξ = 1.

[0079] Although the embodiments of the present invention are described with practical solutions, they do not constitute limitations on the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A method for optimizing process parameters of underwater heavy hammer rock drilling, characterized in that: The preferred method comprises the following steps: S1. Select the appropriate type of rock hammer according to the bedrock type of the site; S2. Drill bedrock core samples from the site, conduct bedrock rock drop hammer tests at different drop hammer speeds on the bedrock core samples, and record the bedrock rock drop hammer test values; S3. Perform numerical simulation calculation of bedrock drop hammer based on the bedrock type and basic physical parameters of the site, compare the bedrock drop hammer test value with the simulation calculation results, and inversely generate bedrock constitutive model parameters; S4. Based on the parameters of the bedrock constitutive model and the selected rock hammer type, rock drilling test simulation calculations of rock hammers with different blade angles are carried out to determine the optimal rock hammer blade angle θr; S5. Based on the optimal rock hammer blade angle θ r Carry out simulation calculation of single-point single-shot rock drilling test, and determine the optimal drop hammer speed V through the ratio of rock plastic damage volume to the square of drop hammer speed r And the corresponding optimal drop height H r ; S6. Based on the optimal rock hammer blade angle θ r and the optimal drop velocity V r And the optimal drop height H r , carry out simulation calculation of single-point multiple rock drilling test to determine the optimal number of hammer drops n r ; S7, based on the optimal number of hammer drops n r The volume of rock plastic damage formed is used to calculate the equivalent radius of the rock plastic zone in single-point multiple rock drilling, determine the drilling point distance, and thus determine the underwater heavy hammer rock drilling process parameters.

2. The method for optimizing underwater heavy hammer rock drilling process parameters according to claim 1, characterized in that: In step S1, a corresponding rock hammer type is selected, specifically by the following steps: S1.

1. Obtain the saturated uniaxial compressive strength and integrity of bedrock; S1.

2. Determine the bedrock type according to the saturated uniaxial compressive strength and integrity, and select the corresponding rock hammer.

3. The method for optimizing process parameters of underwater heavy hammer rock drilling according to claim 1, characterized in that: In step S4, the optimal rock hammer blade angle θ is determined r , specifically through the following steps: S4.

1. Setting a gradual increasing rock hammer blade angle; S4.

2. Carry out simulation calculation of rock drilling test at single point and single time with different rock hammer blade angles, and obtain the rock plastic damage volume under each rock hammer blade angle; S4.

3. With the rock hammer blade angle as the abscissa and the first rock plastic damage volume as the ordinate, a first curve is drawn. The rock hammer blade angle corresponding to the peak value of the first curve is the optimal rock hammer blade angle θ. r .

4. The method for optimizing underwater heavy hammer rock drilling process parameters according to claim 1, characterized in that: In step S5, the optimal drop speed V is determined. r , specifically through the following steps: S5.

1. Setting a gradual increasing rock hammer drop speed; S5.

2. Carry out simulation calculation of single-point single-shot rock drilling test in water, test and record the corresponding rock plastic damage volume; S5.

3. Take the drop hammer speed as the horizontal coordinate and the ratio of the second rock plastic damage volume to the square of the drop hammer speed as the vertical coordinate to obtain the second curve. The drop hammer speed corresponding to the peak value of the second curve is the optimal drop hammer speed V r .

5. The method for optimizing process parameters of underwater heavy hammer rock drilling according to claim 4, characterized in that: In step S5, the specific formula for determining the optimal drop height is: Among them, H r is the falling height, v r is the falling speed, g is the acceleration due to gravity, and S is the water depth.

6. The method for optimizing process parameters of underwater heavy hammer rock drilling according to claim 5, characterized in that: In step S6, the optimal number of hammer drops n is determined. r , specifically through the following steps: S6.

1. Carry out simulation calculation of single-point multiple drop hammer rock drilling test in water, test and record the number of drop hammers and the corresponding rock plastic damage volume; S6.

2. With the single-point hammer drop times as the horizontal coordinate and the ratio of the rock plastic damage volume to the hammer drop times as the vertical coordinate, a third curve is drawn. The peak value of the third curve corresponds to the hammer drop times, which is the optimal hammer drop times n. r .

7. The method for optimizing process parameters of underwater heavy hammer rock drilling according to claim 6, characterized in that: In step S7, the drilling point distance calculation formula is: Among them, R is the drilling point distance, ξ is the rock system coefficient, and V is the rock plastic damage volume.

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