Monocline stratum tunnel exploration drilling arrangement method and drilling method

Abstract

The present invention relates to the technical field of geological exploration, and provides a method for arranging exploration boreholes and a drilling method for tunnels in a monoclinic formation. The method for arranging exploration boreholes in a monoclinic formation tunnel comprises the following steps: obtaining the unit price ratio a of arranging inclined boreholes and vertical boreholes in the tunnel site area; when sin(θ + β) / (cosθsinθcosβ) < a, continuously arranging vertical boreholes along the tunnel axis in the tunnel site area; when sin(θ + β) / (cosθsinθcosβ) > a, continuously arranging inclined boreholes along the tunnel axis in the tunnel site area, and the dip angle λ of the inclined borehole is 90° - θ; wherein, θ is the apparent dip angle of the rock stratum, with the unit of °; β is the slope angle of the tunnel, with the unit of °, taking the bottom of the borehole as the origin and the horizontal plane where the bottom of the borehole is located as the reference, with upward inclination being positive and downward inclination being negative within the range of the lithology section of the stratum revealed by the borehole. The method of the present invention provides a theoretical basis for which drilling method to adopt under what circumstances for the drilling project in the exploration stage for tunnels passing through a monoclinic formation, reduces the drilling cost, and saves the exploration cost on the basis of realizing continuous geological drilling.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration, in particular to a method for arranging exploration boreholes and a drilling method for tunnels in a monoclinic formation. Background Art

[0002] Drilling is an important means to identify the lithology of strata and test the physical and mechanical parameters of rock and soil in tunnel engineering geological exploration. However, drilling is difficult to implement, has a long construction period, and is costly. Therefore, drilling engineering has always been a key and difficult problem in tunnel exploration.

[0003] Currently, the main drilling methods for tunnel exploration are vertical drilling and inclined drilling. However, in actual engineering, the choice of drilling method mainly depends on the understanding and experience of geological personnel regarding the geological conditions of the tunnel project, lacking theoretical support. This easily leads to an increase in drilling costs and further increases the exploration expenses. Therefore, the problem of which drilling method to adopt under what conditions to achieve the best exploration effect has become an urgent problem to be solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for arranging exploration boreholes and a drilling method for tunnels in a monoclinic formation to reduce drilling costs.

[0005] The technical solution adopted by the present invention to solve its technical problem is: A method for arranging exploration boreholes for tunnels in a monoclinic formation, comprising the following steps:

[0006] Obtain the unit price ratio a of arranging inclined boreholes and vertical boreholes in the tunnel site area;

[0007] When sin(θ + β) / (cosθsinθcosβ) < a, continuously arrange vertical boreholes along the tunnel axis in the tunnel site area; when sin(θ + β) / (cosθsinθcosβ) > a, continuously arrange inclined boreholes along the tunnel axis in the tunnel site area, and the dip angle λ of the inclined borehole is 90° - θ;

[0008] Wherein, θ is the apparent dip angle of the rock stratum, in degrees; β is the slope angle of the tunnel, in degrees. Taking the bottom of the borehole as the origin and the horizontal plane where the bottom of the borehole is located as the reference, it is positive for upward inclination and negative for downward inclination within the range of the stratum lithology revealed by the borehole.

[0009] Further, when arranging vertical boreholes in the tunnel site area, continuously arrange the boreholes along the dip direction of the rock stratum; when arranging inclined boreholes in the tunnel site area, continuously arrange the boreholes against the dip direction of the rock stratum.

[0010] Further, when arranging vertical boreholes in the tunnel site area, the hole spacing between adjacent vertical boreholes is calculated according to formula (1):

[0011] L1 = H1cosθcosβ / sin(θ + β) (1)

[0012] Wherein, L1 is the hole spacing between adjacent vertical holes, in m; H1 is the hole depth of the preceding hole, in m.

[0013] Furthermore, the apparent dip angle of the rock formation is calculated according to formula (2):

[0014] θ=arctan(tanηsinα) (2)

[0015] Among them, η is the true inclination of the rock formation, the unit is °; α is the angle between the rock formation direction and the tunnel axis, the unit is °.

[0016] Furthermore, the boreholes in the tunnel site should be drilled to at least 10m below the tunnel base.

[0017] The monocline stratum tunnel survey drilling method adopts the monocline stratum tunnel survey drilling arrangement method to design a drilling arrangement diagram, and drills holes on the tunnel site area according to the drilling arrangement diagram.

[0018] The beneficial effects of the present invention are as follows: the monocline stratum tunnel exploration drilling arrangement method and drilling method provided by the embodiments of the present invention, for tunnels passing through monocline strata, on the basis of realizing continuous geological drilling, provide a theoretical basis for what drilling method to adopt under what circumstances in the drilling project in the exploration stage, thereby reducing drilling costs and saving exploration costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below; obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the structure of continuously arranging vertical boreholes on the tunnel site;

[0021] Figure 2 It is a schematic diagram of the structure of continuously arranging inclined boreholes on the tunnel site area;

[0022] Figure 3 It is a schematic diagram for judging positive and negative tunnel slope angles;

[0023] Figure 4 It is a graph showing the relationship between the apparent dip of a rock formation and its true dip;

[0024] Figure 5 is a highway tunnel survey drilling arrangement diagram of Example 1;

[0025] Figure 6 It is the highway tunnel survey drilling layout diagram of Example 2.

[0026] The reference numerals in the figure are: 101 - tunnel site area, 102 - inclined borehole, 103 - vertical borehole, 104 - tunnel. Specific implementation manners

[0027] To enable those skilled in the art to better understand the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0028] The embodiment of the present invention provides a method for arranging exploration boreholes for a tunnel in a monoclinic formation, including the following steps:

[0029] S1. Obtain the unit price ratio a of arranging the inclined borehole 102 and the vertical borehole 103 on the tunnel site area 101;

[0030] S2. When sin(θ + β) / (cosθsinθcosβ) < a, continuously arrange the vertical boreholes 103 along the tunnel axis on the tunnel site area 101; when sin(θ + β) / (cosθsinθcosβ) > a, continuously arrange the inclined boreholes 102 along the tunnel axis on the tunnel site area 101, and the dip angle λ of the inclined borehole 102 = 90° - θ;

[0031] Wherein, θ is the apparent dip angle of the rock stratum, and the unit is °; β is the slope angle of the tunnel, and the unit is °. Taking the bottom of the borehole as the origin and the horizontal plane where the bottom of the borehole is located as the reference, it is positive for upward inclination and negative for downward inclination within the range of the stratum lithology section revealed by the borehole.

[0032] Before arranging boreholes on the tunnel site area 101, the topographic data and geological data of the tunnel site area 101 should be collected first, and detailed geological mapping should be carried out to clarify information such as the dip angle of the rock stratum, the strike of the rock stratum, the included angle between the tunnel axis and the strike of the rock stratum, and the slope of the tunnel axis, and fill in and draw the geological longitudinal section diagram of the tunnel.

[0033] In step S1, the method for obtaining the unit price ratio a of arranging the inclined borehole 102 and the vertical borehole 103 on the tunnel site area 101 is as follows: Use the same equipment to drill the inclined borehole 102 and the vertical borehole 103 respectively on the same tunnel site area 101, measure the costs of the inclined borehole 102 and the vertical borehole 103 at the same depth. The cost of the inclined borehole 102 is a1, and the cost of the vertical borehole 103 is a2; then the unit price ratio a of the inclined borehole 102 and the vertical borehole 103 = a1 / a2. This method can be obtained by market inquiry or on-site test, and no specific limitation is made here.

[0034] In step S2, based on the topographic and geological data of the tunnel site area 101, while ensuring continuous drilling, determine which drilling method has a lower cost.

[0035] Figure 1 It is a schematic structural diagram of continuously arranging vertical boreholes 103 on the tunnel site area. See Figure 1 , when continuously arranging vertical boreholes 103 on the tunnel site area 101, the following conditions should be met between two adjacent vertical boreholes 103: the angle between the line connecting the top of the previous vertical borehole 103 and the bottom of the next vertical borehole 103 and the horizontal plane is equal to the apparent dip angle θ of the rock formation.

[0036] Figure 1 In it, H1 is the depth of one of the vertical boreholes 103, and X1 is the effective length of the tunnel strata lithology revealed by this vertical borehole 103 along the tunnel axis; according to the trigonometric function relationship, H1 = X1sin(θ + β) / cosθ. When the total length of the tunnel 104 is X, then the total hole depth of the vertical boreholes 103 drilled on the tunnel site area 101 is H1 ′ = Xsin(θ + β) / cosθ.

[0037] Figure 2 It is a schematic structural diagram of continuously arranging inclined boreholes 102 on the tunnel site area. See Figure 2 , when continuously arranging inclined boreholes 102 on the tunnel site area 101, the drilling dip angle λ of each inclined borehole 102 = 90° - θ; the following conditions should be met between two adjacent inclined boreholes 102: the angle between the line connecting the top of the previous inclined borehole 102 and the bottom of the next inclined borehole 102 and the horizontal plane is equal to the apparent dip angle θ of the rock formation.

[0038] Figure 2 In it, H2 is the depth of one of the inclined boreholes 102, and X2 is the effective length of the tunnel strata lithology revealed by this inclined borehole 102 along the tunnel axis; according to the trigonometric function relationship, H2 = X2sinθcosβ. When the total length of the tunnel 104 is X, then the total hole depth of the inclined boreholes 102 drilled on the tunnel site area 101 is H2 ′ = Xsinθcosβ.

[0039] When continuously arranging boreholes on the tunnel site area 101 with the total length of the tunnel 104 being X, if H1 ′ / H2 ′ < a, it means that the cost of arranging vertical boreholes 103 on the tunnel site area 101 is relatively low. At this time, continuously arranging vertical boreholes 103 along the tunnel axis on the tunnel site area 101 can achieve the purpose of reducing the exploration cost; if H1 ′ / H2 ′>a, it means that the cost of arranging the inclined boreholes 102 on the tunnel site area 101 is relatively low. At this time, continuously arranging the inclined boreholes 102 along the tunnel axis on the tunnel site area 101 can achieve the purpose of reducing the exploration cost.

[0040] See also Figure 3 In the figure, c and d are two different tunnel layouts. With the bottom of the borehole at a depth of H1 as the origin and the horizontal plane where the bottom of the borehole is located as the reference, within the range L1 of the stratum lithology section revealed by the borehole, the c tunnel is down-pitched and the d tunnel is up-pitched; outside the range L1 of the stratum lithology section revealed by the borehole, that is, on the right side of the borehole, the c tunnel is up-pitched and the d tunnel is down-pitched. The up-pitching and down-pitching of the tunnel have an impact on the effective revealing length, so it is stipulated that: with the bottom of the borehole as the origin and the horizontal plane where the bottom of the borehole is located as the reference, and with the stratum lithology section revealed by the borehole as the range, when the tunnel is up-pitched, the tunnel angle β is a positive value; when the tunnel is down-pitched, the tunnel angle β is a negative value.

[0041] The monocline stratum tunnel exploration drilling arrangement method provided in the embodiment of the present invention, for tunnels passing through monocline strata, provides a theoretical basis for what drilling method to adopt under what circumstances in the drilling project during the exploration stage on the basis of realizing continuous geological drilling, thereby reducing drilling costs and saving exploration costs.

[0042] The method for arranging drilling holes for monocline stratum tunnel survey provided by the embodiment of the present invention is to arrange vertical boreholes 103 on the tunnel site 101 continuously along the inclination of the rock strata; and to arrange inclined boreholes 102 on the tunnel site 101 continuously against the inclination of the rock strata. Figure 1 When vertical boreholes 103 are continuously arranged on the tunnel site 101, according to the tripod function relationship, the hole spacing between adjacent vertical boreholes 103 is calculated according to formula (1):

[0043] L1=H1cosθcosβ / sin(θ+β) (1)

[0044] Wherein, L1 is the hole spacing between adjacent vertical drill holes 103, the unit is m; H1 is the hole depth of the preceding drill hole, the unit is m.

[0045] In the monocline stratum tunnel survey drilling arrangement method provided by the embodiment of the present invention, the apparent inclination angle of the rock stratum is calculated according to formula (2):

[0046] θ=arctan(tanηsinα) (2)

[0047] Among them, η is the true inclination of the rock formation, the unit is °; α is the angle between the rock formation direction and the tunnel axis, the unit is °.

[0048] See also Figure 4, MN is the direction of the rock formation, BD is the axis of the tunnel, and the angle between the direction of the rock formation MN and the axis of the tunnel BD is α; in the figure, MN, AD, and CD are perpendicular to each other, the angle between AB and BD is the apparent inclination angle θ of the rock formation, and the angle between AC and CD is the true inclination angle η of the rock formation. Among them, tanθ=AD / BD, tanη=AD / CD, sinα=CD / BD; thus, tanθ=tanηsinα, and after conversion, we get: θ=arctan(tanηsinα).

[0049] The drilling depths of the vertical borehole 103 and the inclined borehole 102 should be set according to the requirements of the Railway Engineering Geological Survey Specifications, and are not specifically limited here. As an implementation method, the boreholes on the tunnel site 101 should be drilled to at least 10m below the tunnel base.

[0050] The embodiment of the present invention also provides a monocline stratum tunnel survey drilling method, which uses the monocline stratum tunnel survey drilling arrangement method to design a drilling arrangement diagram, and drills holes on the tunnel site area 101 according to the drilling arrangement diagram. This provides a theoretical basis for the drilling project in the survey stage to determine which drilling method to use under what circumstances, thereby minimizing the drilling cost, thereby saving survey costs, and achieving the economy and rationality of the project.

[0051] Embodiment 1:

[0052] See also Figure 5 The length of a highway tunnel is 1035.7m, and the maximum burial depth is 199.5m; the mileage of the left end of the tunnel is 1035.7m, and the mileage of the right end is 0m; Tunnel 104 is designed as a single-sided uphill with a slope of 1‰, which is almost horizontal; Tunnel 104 passes through a monocline stratum, the stratum lithology is muddy sandstone, the true inclination angle of the stratum is η=31°, and the stratum strike is 121°; the angle between the stratum strike and the tunnel axis is α=82°. The borehole is drilled to 10m below the tunnel base.

[0053] Within the range of a certain borehole revealing the lithology section, the tunnel slope angle β is judged to be positive based on the horizontal plane where the bottom of the borehole is located; since the tunnel slope is nearly horizontal, the tunnel slope angle β is taken as 0° in subsequent calculations.

[0054] Calculate the apparent inclination angle of the rock formation θ = arctan (tan31°×sin82°) = 30.75°.

[0055] Through market inquiry, it was obtained that the unit price ratio of arranging the inclined borehole 102 and the vertical borehole 103 on the tunnel site area 101 is a=1.68.

[0056] Since sin(30.75° + 0°) / (cos30.75°×sin30.75°×cos0°) = 1.164 < a, vertical boreholes 103 are continuously arranged along the dip direction of the rock stratum along the tunnel axis on the tunnel site area 101, that is, the boreholes are arranged from the small mileage end to the large mileage end.

[0057] According to the dip angle of the rock stratum and the requirement of drilling depth to the base, the position of borehole DZ - 01 is determined to be at mileage 16.80m, and the borehole depth is 15.0m;

[0058] Calculating the borehole spacing L1 towards the large mileage: L1 = 15×cos30.75°×cos0° / sin(30.75° + 0°) = 25.21m, and the position of borehole DZ - 02 is determined to be at mileage 42.01m, and the borehole depth is 36.5m;

[0059] Calculating the borehole spacing L1 towards the large mileage: L1 = 36.5×cos30.75°×cos0° / sin(30.75° + 0°) = 61.35m, and the position of borehole DZ - 03 is determined to be at mileage 103.36m, and the borehole depth is 82.5m;

[0060] Calculating the borehole spacing L1 towards the large mileage: L1 = 82.5×cos30.75°×cos0° / sin(30.75° + 0°) = 138.67m, and the position of borehole DZ - 04 is determined to be at mileage 242.03m, and the borehole depth is 184.5m;

[0061] Calculating the borehole spacing L1 towards the large mileage: L1 = 184.5×cos30.75°×cos0° / sin(30.75° + 0°) = 310.12m, and the position of borehole DZ - 05 is determined to be at mileage 552.15m, and the borehole depth is 192.5m;

[0062] Calculating the borehole spacing L1 towards the large mileage: L1 = 192.5×cos30.75°×cos0° / sin(30.75° + 0°) = 323.56m, and the position of borehole DZ - 06 is determined to be at mileage 875.71m, and the borehole depth is 39.0m;

[0063] Calculating the borehole spacing L1 towards the large mileage: L1 = 39×cos30.75°×cos0° / sin(30.75° + 0°) = 65.55m, and the position of borehole DZ - 07 is determined to be at mileage 941.26m, and the borehole depth is 58.5m;

[0064] Calculating the borehole spacing L1 towards the large mileage: L1 = 58.5×cos30.75°×cos0° / sin(30.75° + 0°) = 98.33m, and the position of borehole DZ - 08 is determined to be at mileage 1039.59m, which is outside the tunnel mileage range, and the borehole layout is completed.

[0065] The arrangement of the vertical drilling holes in Example 1 is shown in Table 1 below.

[0066]

[0067]

[0068] According to the drilling arrangement in the above table, holes are drilled on the tunnel site 101 to complete the monocline stratum tunnel exploration drilling work. In this way, on the basis of achieving continuous drilling, the drilling cost is reduced, the exploration fee is saved, and the economy and rationality of the project are achieved.

[0069] Embodiment 2:

[0070] See also Figure 6 The length of a highway tunnel 104 is 712.2m, and the maximum burial depth is 240.1m; the mileage of the left end of the tunnel is 712.2m, and the mileage of the right end is 0m; Tunnel 104 is designed to be a single-sided uphill with a slope of 2‰, which is almost horizontal; Tunnel 104 passes through a monocline stratum, the stratum lithology is muddy sandstone, the true inclination angle of the stratum is η=65°, and the stratum strike is 31°; the angle between the stratum strike and the tunnel axis is α=85°. The borehole is drilled to 10m below the tunnel base.

[0071] Within the range of a certain borehole revealing the lithology section, the tunnel slope angle β is judged to be positive based on the horizontal plane where the bottom of the borehole is located; since the tunnel slope is nearly horizontal, the tunnel slope angle β is taken as 0° in subsequent calculations.

[0072] The calculated apparent inclination angle of the rock formation is θ = arctan (tan65°×sin85°) = 64.91°.

[0073] Through market inquiry, it was obtained that the unit price ratio of arranging the inclined borehole 102 and the vertical borehole 103 on the tunnel site area 101 is a=1.68.

[0074] Since sin(64.91°+0°) / (cos64.91°×sin64.91°×cos0°)=2.358>a, inclined boreholes 102 are continuously arranged along the tunnel axis against the inclination of the rock strata at the tunnel site 101, that is, the boreholes are arranged from the large mileage end to the small mileage end, and the drilling angle λ of the inclined boreholes 102 is 90°-64.91°=35.09°.

[0075] According to the rock formation inclination and the depth requirement of drilling to the base, the DZ-01 borehole location was determined to be at 416.55m, with a hole depth of 324.0m, revealing a formation mileage of 712.20m to 352.70m;

[0076] According to the borehole depression angle and the stratigraphic boundary mileage of 352.70m revealed by the previous borehole, the boreholes were arranged towards the smaller mileages, and the position of DZ-02 borehole was determined to be at the mileage of 153.25m, with a hole depth of 220.0m, revealing a stratigraphic mileage of 352.70m to 109.85m;

[0077] According to the borehole depression angle and the stratigraphic boundary mileage of 109.85m revealed by the previous borehole, the boreholes were arranged towards the smaller mileages, and the position of the DZ-03 borehole was determined to be at the mileage of 24.20m, with a hole depth of 94.5m, revealing a stratigraphic mileage of 109.85m to 5.60m;

[0078] According to the borehole depression angle and the stratigraphic boundary mileage of 5.60m revealed by the previous borehole, holes were arranged towards smaller mileages, and the DZ-04 borehole position was determined to be at mileage -3.40m, with a hole depth of 9.5m, revealing a stratigraphic mileage of 5.60m to -0.4m; the stratigraphic boundary was revealed to be outside the tunnel mileage range, and the drilling arrangement was completed.

[0079] The arrangement of the inclined drilling holes in Example 2 is shown in the following table.

[0080]

[0081]

[0082] According to the drilling arrangement in the above table, holes are drilled on the tunnel site 101 to complete the monocline stratum tunnel exploration drilling work. In this way, on the basis of achieving continuous drilling, the drilling cost is reduced, the exploration fee is saved, and the economy and rationality of the project are achieved.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for arranging drilling holes for tunnel exploration in monocline strata, characterized in that: The method includes the following steps: Obtain the unit price ratio a of the inclined borehole (102) and the vertical borehole (103) arranged on the tunnel site area (101). Use the same equipment to drill the inclined borehole (102) and the vertical borehole (103) respectively on the same tunnel site area (101), and measure the construction costs of the inclined borehole (102) and the vertical borehole (103) at the same depth. The construction cost of the inclined borehole (102) is a1, and the construction cost of the vertical borehole (103) is a2. The unit price ratio a of the inclined borehole (102) and the vertical borehole (103) is a = a1 / a2; When sin(θ + β) / (cosθsinθcosβ) < a, continuously arrange vertical boreholes (103) along the tunnel axis on the tunnel site area (101); when sin(θ + β) / (cosθsinθcosβ) > a, continuously arrange inclined boreholes (102) along the tunnel axis on the tunnel site area (101), and the dip angle λ of the inclined borehole (102) is λ = 90° - θ; Wherein, θ is the apparent dip angle of the rock stratum, and the unit is °; β is the slope angle of the tunnel, and the unit is °. Taking the bottom of the borehole as the origin and the horizontal plane where the bottom of the borehole is located as the reference, upward is positive and downward is negative within the range of the rock stratum lithology section revealed by the borehole.

2. The monocline stratum tunnel exploration drilling arrangement method according to claim 1, characterized in that: When arranging vertical boreholes (103) on the tunnel site area (101), continuously arrange the boreholes along the dip direction of the rock stratum; when arranging inclined boreholes (102) on the tunnel site area (101), continuously arrange the boreholes against the dip direction of the rock stratum.

3. The method for arranging drilling holes for tunnel survey in monocline strata according to claim 1, characterized in that: When arranging vertical boreholes (103) on the tunnel site area (101), the hole spacing between adjacent vertical boreholes (103) is calculated according to formula (1): L1 = H1cosθcosβ / sin(θ + β) (1) Wherein, L1 is the hole spacing between adjacent vertical boreholes (103), and the unit is m; H1 is the hole depth of the previous borehole, and the unit is m.

4. The method for arranging drilling holes for tunnel survey in monocline strata according to claim 1, characterized in that: The apparent dip angle of the rock stratum is calculated according to formula (2): θ = arctan(tanηsinα) (2) Wherein, η is the true dip angle of the rock stratum, and the unit is °; α is the included angle between the strike of the rock stratum and the tunnel axis, and the unit is °.

5. The method for arranging drilling holes for monocline stratum tunnel survey according to claim 1, characterized in that: When drilling holes on the tunnel site area (101), the drilling should reach at least 10 m below the tunnel base.

6. A method for tunnel exploration and drilling in monocline strata, characterized in that: Design a borehole layout plan by using the single inclined stratum tunnel exploration borehole layout method described in any one of claims 1 to 5, and drill holes on the tunnel site area (101) according to the borehole layout plan.

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