Tunnel horizontal directional drilling arrangement method

Abstract

The invention relates to the technical field of tunnel drilling, in particular to a tunnel horizontal directional drilling arrangement method which comprises the following steps: selecting a tunnel excavation process; when a drilling and blasting method is adopted for excavation, the drilling position of horizontal directional drilling is arranged in the contour line of the tunnel face. When a heading machine or a shield method is adopted for excavation, the drilling position of horizontal directional drilling is arranged outside the contour line of the tunnel face; meanwhile, according to the occurrence of the rock stratum, the rock stratum to be excavated is divided into five categories, and the drilling positions are arranged according to the categories. According to different tunnel excavation processes and the occurrence of a rock stratum to be excavated, the arrangement positions of drill holes for horizontal directional drilling of a tunnel are selected. By means of the method, dependence on experience judgment can be reduced, drill hole arrangement is more scientific and reasonable, unnecessary drilling operation is avoided, the number of drill holes and the exploration workload are reduced, the exploration cost is reduced, and the exploration period is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel drilling, and in particular to a method for arranging horizontal directional drilling holes in a tunnel. Background Art

[0002] With the rapid development of my country's transportation network infrastructure construction, large-scale engineering projects such as railways and highways have sprung up in the western region, especially in mountainous areas. These projects often face complex and changeable terrain challenges, among which the most notable features are significant elevation differences and drastic ups and downs. Therefore, it is inevitable to use long and deep tunnels as the key engineering technology solution for crossing mountainous areas. In the preliminary survey stage of long and deep tunnels, horizontal directional drilling technology plays a vital role. However, current drilling operations face a series of severe challenges, including but not limited to high implementation difficulty, high economic cost and long operation cycle. These factors together constitute a major obstacle to the high-precision survey of long and deep tunnels.

[0003] In current practice, the arrangement of boreholes mainly relies on the engineering intuition and experience of on-site technicians. This approach is highly subjective and often lacks sufficient pertinence and theoretical support. In order to ensure the accuracy of the survey results, the number and depth of drilling are often increased. Although this approach can improve the survey accuracy, it will increase the survey cost and extend the survey period. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art that the hole arrangement of horizontal directional drilling relies on experience judgment, lacks specificity, leads to increased survey costs and extended survey cycles, and provides a method for arranging horizontal directional drilling holes in a tunnel.

[0005] The present invention provides a method for arranging horizontal directional drilling holes in a tunnel, comprising the following steps:

[0006] S1: Select tunnel excavation technology;

[0007] S2: When the drill and blast method is used for excavation, the boreholes for horizontal directional drilling are arranged within the contour of the tunnel face;

[0008] When excavation is carried out by using a roadheader or shield method, the drilling position of the horizontal directional drilling is arranged outside the contour line of the tunnel face, and the rock formation to be excavated is divided into five categories according to the rock formation occurrence: rock formation with the same inclination as the tunnel axis direction, rock formation with the rock formation plane parallel to the horizontal plane, rock formation with the rock formation plane perpendicular to the horizontal plane, rock formation with the rock formation plane inclined to the left, and rock formation with the rock formation plane inclined to the right;

[0009] When the rock stratum to be excavated is a rock stratum whose inclination is consistent with the tunnel axis direction, a borehole is arranged outside the contour line of the tunnel face, and the azimuth angle of the borehole position is 90° or 270°;

[0010] When the rock layer to be excavated is a rock layer whose rock layer surface is parallel to the horizontal plane, two boreholes are arranged outside the contour line of the tunnel face, and the azimuth angles of the two borehole positions are 0° and 180° respectively;

[0011] When the rock layer to be excavated is a rock layer whose rock layer surface is perpendicular to the horizontal plane, a borehole is arranged outside the contour line of the tunnel face, and the azimuth angle of the borehole position is 90° or 270°;

[0012] When the rock layer to be excavated is a rock layer inclined to the left, two boreholes are arranged outside the contour line of the tunnel face, and the two borehole positions are respectively located in a first area and a second area outside the contour line of the tunnel face;

[0013] When the rock layer to be excavated is a rock layer inclined to the right, two boreholes are arranged outside the contour line of the tunnel face, and the two borehole positions are respectively located in the third area and the fourth area outside the contour line of the tunnel face.

[0014] The present invention provides a method for arranging horizontal directional drilling holes in a tunnel, which selects the arrangement positions of holes for horizontal directional drilling of the tunnel according to different tunnel excavation processes and the occurrence of the rock formation to be excavated. This method can reduce the reliance on empirical judgment, make the arrangement of holes more scientific and reasonable, avoid unnecessary drilling operations, thereby reducing the number of holes and the workload of exploration, thereby reducing the exploration cost and shortening the exploration period.

[0015] The selection of tunnel excavation technology belongs to the existing technology. Generally, the corresponding excavation technology of the tunnel is selected according to the geological conditions, tunnel length and cross-sectional size. The excavation technologies that can be used include drilling and blasting, tunnel boring machine or shield method.

[0016] When the drill and blast method is used for excavation, the drilling positions of the horizontal directional drilling are arranged within the contour line of the tunnel face, and the number of drilling holes arranged here can be one or more.

[0017] The tunnel face refers to the excavation face perpendicular to the longitudinal axis of the tunnel excavation.

[0018] The intersection line of the rock layer and any imaginary horizontal plane is called the strike line, that is, the line connecting two points of equal height on the same plane. The direction in which the two ends of the strike line extend is called the strike of the rock layer, and the strike of the rock layer indicates the horizontal extension direction of the rock layer in space. The straight line on the rock layer that is perpendicular to the strike line and drawn downward along the slope is called the inclination line, which indicates the maximum slope of the rock layer. The direction indicated by the projection of the inclination line on the horizontal plane is called the dip of the rock layer, and the acute angle between the inclination line and the horizontal plane is called the true dip of the rock layer.

[0019] When the tunnel excavation direction is consistent with the inclination direction of the rock strata, such rock strata are called rock strata whose inclination is consistent with the tunnel axis direction.

[0020] A rock layer whose plane is parallel to the horizontal plane, specifically a rock layer in which all points on the same rock layer have the same altitude, is also called a horizontal rock layer.

[0021] A rock stratum whose layer is perpendicular to the horizontal plane, specifically a rock stratum whose angle between the layer and the horizontal plane is 90°, is also called a vertical rock stratum.

[0022] When an observer stands on the tunnel face facing the rock stratum to be excavated, if the surface of the rock stratum to be excavated is rotated clockwise around its strike line by an angle (the angle is the true inclination angle of the rock stratum to be excavated), it can become horizontal. Such a rock stratum is called a rock stratum with a surface inclined to the left.

[0023] When an observer stands on the tunnel face facing the rock stratum to be excavated, if the layer of the rock stratum to be excavated is rotated counterclockwise around its strike line by an angle (the angle is the true inclination angle of the rock stratum to be excavated), it can become horizontal. Such a rock stratum is called a rock stratum with the layer inclined to the right.

[0024] The azimuth angle refers to the azimuth angle defined by the angle rotated clockwise with the center of the tunnel face as the center of the circle and the 12 o'clock direction (directly above) as the starting point.

[0025] The first area refers to the area on the upper left side of the tunnel when an observer stands on the tunnel face facing the rock layer to be excavated.

[0026] The second area refers to the area at the lower right side of the tunnel when an observer stands on the tunnel face facing the rock layer to be excavated.

[0027] The third area refers to the area on the upper right side of the tunnel when the observer stands on the tunnel face facing the rock layer to be excavated.

[0028] The fourth area refers to the area at the lower left of the tunnel when the observer stands on the tunnel face facing the rock layer to be excavated.

[0029] Preferably, in step S2, when the drilling and blasting method is used for excavation, the drilling positions of the horizontal directional drilling are arranged in a circular area with a radius of 2 meters at the center of the tunnel face. This solution further enhances the pertinence and accuracy of the drilling arrangement of the horizontal directional drilling when the drilling and blasting method is used for excavation.

[0030] Preferably, in step S2, when the drilling and blasting method is used for excavation, the drilling position of the horizontal directional drilling is arranged at the center of the tunnel face. This solution can more directly determine the drilling arrangement of the horizontal directional drilling, further improving the efficiency of the survey and construction. This solution accurately arranges the drilling holes at the center of the tunnel face, which can more effectively evaluate the geological conditions in front of the tunnel face and provide accurate geological information for subsequent blasting operations, thereby reducing construction delays and adjustments caused by geological uncertainties.

[0031] Preferably, in step S2, when the rock stratum to be excavated is a rock stratum with a rock stratum surface inclined to the left, the azimuth angles of the two drilling positions are β1 and β2 respectively, and the calculation formulas of β1 and β2 are as follows:

[0032] β1=270°+α

[0033] β2=90°+α

[0034] α=arctan(ηtanγsinμ)

[0035] Among them, β1 represents the azimuth when the drilling position is located at the upper left of the tunnel; β2 represents the azimuth when the drilling position is located at the lower right of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, that is, the depth direction of the rock formation and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ is the true inclination of the rock formation; μ is the angle between the rock formation strike and the tunnel face.

[0036] The plan further clarifies the arrangement position of the boreholes for horizontal directional drilling when the rock layer to be excavated is a rock layer inclined to the left.

[0037] The definition of the apparent dip angle of the rock formation is: when the section and the rock formation strike are oblique, the intersection line of the rock formation and the section is called the apparent dip line, and the angle between the apparent dip line and its projection line on the horizontal plane is called the apparent dip angle of the rock formation. The section in this application corresponds to the tunnel face.

[0038] Preferably, in step S2, when the rock stratum to be excavated is a rock stratum with a rock stratum surface inclined to the right, the azimuth angles of the two drilling positions are β3 and β4 respectively, and the calculation formulas of β3 and β4 are as follows:

[0039] β3=90°-α

[0040] β4=270°-α

[0041] α=arctan(ηtanγsinμ)

[0042] Among them, β3 represents the azimuth when the drilling position is located at the upper right of the tunnel; β4 represents the azimuth when the drilling position is located at the lower left of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, that is, the depth direction of the rock formation and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ is the true inclination of the rock formation; μ is the angle between the rock formation strike and the tunnel face.

[0043] The plan further clarifies the layout of the boreholes for horizontal directional drilling when the rock layer to be excavated is a rock layer that is inclined to the right.

[0044] Preferably, in step S2, when excavation is carried out using a roadheader or a shield method, the drilling position of the horizontal directional drilling is arranged at a position 1 meter to 5 meters outside the contour line of the tunnel face.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention provides a method for arranging horizontal directional drilling holes in a tunnel, which selects the arrangement positions of holes for horizontal directional drilling of the tunnel according to different tunnel excavation processes and the occurrence of the rock formation to be excavated. This method can reduce the reliance on empirical judgment, make the arrangement of holes more scientific and reasonable, avoid unnecessary drilling operations, thereby reducing the number of holes and the workload of exploration, thereby reducing the exploration cost and shortening the exploration period. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The present invention is a flow chart of a method for arranging horizontal directional drilling holes in a tunnel.

[0048] Figure 2 This is a schematic diagram of the first cross section.

[0049] Figure 3 This is a schematic diagram of the second cross section.

[0050] Figure 4 This is a schematic diagram of the first longitudinal section.

[0051] Figure 5 This is a schematic diagram of the third cross section.

[0052] Figure 6 This is a schematic diagram of the second longitudinal section.

[0053] Figure 7This is a schematic diagram of the fourth cross section.

[0054] Figure 8 This is a schematic diagram of the fifth cross section.

[0055] Fig. 9 This is a schematic diagram of the sixth cross section.

[0056] Fig.10 This is a cross-sectional schematic diagram of Case 1 in Example 2.

[0057] Fig.11 This is a cross-sectional schematic diagram of Case 2 in Example 2.

[0058] Markings in the figure:

[0059] 1- rock layer to be excavated, 2- contour line, 3- drilling position, 4- rock layer interface, 5- first area, 6- second area, 7- third area, 8- fourth area. DETAILED DESCRIPTION

[0060] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0061] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0062] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0063] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0064] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0065] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0066] Example 1

[0067] like Figure 1 As shown, a method for arranging horizontal directional drilling holes in a tunnel comprises the following steps:

[0068] S1: Select the tunnel excavation method. The specific excavation methods that can be selected are: drilling and blasting method, tunnel boring machine method and shield method.

[0069] S2: When the drilling and blasting method is used for excavation, the drilling position 3 of the horizontal directional drilling is arranged within the contour line 2 of the tunnel face.

[0070] When excavation is carried out by a tunnel boring machine or a shield method, the drilling position 3 of the horizontal directional drilling is arranged outside the contour line 2 of the tunnel face, and the rock strata 1 to be excavated is divided into five categories according to the rock strata occurrence, namely, rock strata with a rock strata inclination consistent with the direction of the tunnel axis, rock strata with a rock strata plane parallel to the horizontal plane, rock strata with a rock strata plane perpendicular to the horizontal plane, rock strata with a rock strata plane inclined to the left, and rock strata with a rock strata plane inclined to the right.

[0071] When the rock layer 1 to be excavated is a rock layer with the same inclination as the tunnel axis, Figure 3 , Figure 4 As shown, a borehole is arranged outside the contour line 2 of the tunnel face, and the azimuth angle of the borehole position 3 is 90° or 270°. A rock layer interface 4 is between two adjacent rock layers. Figure 4 The area between the two dotted lines is the rock layer 1 to be excavated.

[0072] When the rock layer 1 to be excavated is a rock layer whose rock layer surface is parallel to the horizontal plane, Figure 5 , Figure 6 As shown, two boreholes are arranged outside the contour line 2 of the tunnel face, and the azimuth angles of the two borehole positions 3 are 0° and 180° respectively. Figure 6 The area between the two dotted lines is the rock layer 1 to be excavated.

[0073] When the rock layer 1 to be excavated is a rock layer whose rock layer surface is perpendicular to the horizontal plane, such as Figure 7 As shown, a borehole is arranged outside the contour line 2 of the tunnel face, and the azimuth angle of the borehole position 3 is 90° or 270°.

[0074] When the rock layer 1 to be excavated is a rock layer with the rock layer surface inclined to the left, Figure 8 As shown, two drill holes are arranged outside the contour line 2 of the tunnel face, and the two drill hole positions 3 are respectively located in a first area 5 and a second area 6 outside the contour line 2 of the tunnel face.

[0075] When the rock layer 1 to be excavated is a rock layer with the rock layer surface inclined to the right, Fig. 9 As shown, two drill holes are arranged outside the contour line 2 of the tunnel face, and the two drill hole positions 3 are respectively located in a third area 7 and a fourth area 8 outside the contour line 2 of the tunnel face.

[0076] When excavation is carried out by a tunnel boring machine or a shield method, the holes for horizontal directional drilling are arranged outside the contour line 2 of the tunnel face. The specific drilling operation process is as follows: First, starting from the tunnel face to be excavated, drilling is performed at an oblique angle to the outside of the contour line 2 of the tunnel face. When the drilling reaches the predetermined position outside the contour line 2, the direction of the drill rod is then adjusted to make it parallel to the tunnel axis, and the drilling is continued. Through this operation method, the drilling position 3 of the horizontal directional drilling can be arranged outside the contour line 2 of the tunnel face.

[0077] In an optional implementation, in step S2, when the drill and blast method is used for excavation, the drilling position 3 of the horizontal directional drilling can be arranged in a circular area with a central radius of 2 meters on the tunnel face, and the specific number of drilling holes is one or two.

[0078] In an optional embodiment, in S2, when the drilling and blasting method is used for excavation, Figure 2 As shown, the drilling position 3 of the horizontal directional drilling can be arranged at the center of the tunnel face, and the number of the drilling holes is one.

[0079] In an optional embodiment, in step S2, when the rock layer 1 to be excavated is a rock layer with a rock layer surface inclined to the left, Figure 8 As shown, the azimuth angles of the two drilling positions 3 can be β1 and β2 respectively, and the calculation formulas of β1 and β2 are as follows:

[0080] β1=270°+α

[0081] β2=90°+α

[0082] α=arctan(ηtanγsinμ)

[0083] Among them, β1 represents the azimuth when the drilling position 3 is located at the upper left of the tunnel; β2 represents the azimuth when the drilling position 3 is located at the lower right of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, that is, the depth direction of the rock formation and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ is the true inclination of the rock formation; μ is the angle between the rock formation strike and the tunnel face.

[0084] In an optional implementation manner, in step S2, when the rock stratum 1 to be excavated is a rock stratum inclined to the right, the azimuth angles of the two drilling positions 3 may be β3 and β4, respectively, and the calculation formulas of β3 and β4 are as follows:

[0085] β3=90°-α

[0086] β4=270°-α

[0087] α=arctan(ηtanγsinμ)

[0088] Among them, β3 represents the azimuth when the drilling position 3 is located at the upper right of the tunnel; β4 represents the azimuth when the drilling position 3 is located at the lower left of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, that is, the depth direction of the rock formation and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ is the true inclination of the rock formation; μ is the angle between the rock formation strike and the tunnel face.

[0089] In an optional embodiment, in step S2, when excavation is carried out using a tunnel boring machine or a shield method, the drilling position 3 of the horizontal directional drilling can be arranged at a position 1 meter to 5 meters outside the contour line 2 of the tunnel face, specifically 1 meter, 1.5 meters, 2 meters, 2.5 meters, 3 meters, 3.5 meters, 4 meters, 4.5 meters, or 5 meters outside the contour line 2 of the tunnel face.

[0090] Example 2

[0091] This embodiment applies the tunnel horizontal directional drilling arrangement method described in Embodiment 1 to two engineering projects, thereby forming practical examples of Case 1 and Case 2.

[0092] Case 1

[0093] This case is a case where the rock layer 1 to be excavated is a rock layer with a rock layer surface inclined to the left, such as Fig.10 As shown, the ratio η of the longitudinal scale to the transverse scale in the project of this case is 1. The lithology of the tunnels in this project is mostly hard rocks such as calcareous sandstone and limestone. There is a risk of water gushing and mud bursting. The overall integrity of the surrounding rock is good, and the shield machine excavation method is adopted.

[0094] The compass measured that the rock formation 1 to be excavated at the tunnel face position is N35°E, the rock formation dip azimuth is 320°, the rock formation true dip angle γ is 40°, and the direction of the tunnel axis is N80°E. According to the direction of the tunnel axis, the direction of the tunnel face projection on the horizontal plane can be obtained as N10°W, so the angle μ between the rock formation direction and the tunnel face is 10°+35°=45°. The rock formation dip refers to the direction of the projection of the vertical line (inclined line) perpendicular to the rock formation strike line and drawn downward along the layer on the horizontal plane. The rock formation dip azimuth refers to the clockwise angle between the dip line and the due north direction on the horizontal plane. According to the above situation, it is comprehensively judged that the rock formation 1 to be excavated in this project is a rock formation with a leftward tilt on the rock formation layer. Therefore, two boreholes are arranged outside the contour line 2 of the tunnel face, and the azimuths of the two borehole positions 3 are β1 and β2. The calculation formulas for β1 and β2 are as follows:

[0095] β1=270°+α

[0096] β2=90°+α

[0097] α=arctan(ηtanγsinμ)

[0098] Among them, η=1, γ=40°, and μ=45°.

[0099] Therefore, α=arctan(1×tan40°×sin45°)=30°.

[0100] Therefore, β1=270°+α=270°+30°=300°, β2=90°+α=90°+30°=120°.

[0101] According to the above calculation results, a borehole was arranged at 3m to 5m outside the contour line 2 of the tunnel face, with azimuths of 120° and 300° respectively. After horizontal directional drilling, the borehole with an azimuth of 120° revealed the existence of soluble rocks such as limestone on the right side of the tunnel face. During the drilling process, water flow appeared in strands, with a water volume of about 50 to 60m 3 / h. The drilling with an azimuth angle of 300° revealed the presence of calcareous sandstone on the left side of the tunnel face. Based on the occurrence of the rock formations, the current face and the distribution of soluble rocks in front were inferred. In view of soluble rocks such as limestone and strand-shaped water discharge, two targeted drainage holes were promptly arranged at the distribution location of the limestone, and the water volume gradually decreased. When excavating to soluble rock formations such as limestone, the air gun drilling (air gun deepening blasthole) detection scheme was promptly used to carry out hidden karst detection operations around the tunnel and at the bottom of the tunnel, and the karst development around the tunnel, especially within a certain depth range at the bottom of the tunnel, was accurately identified.

[0102] Through a tunnel horizontal directional drilling arrangement method applied in the present invention, it is possible to quantitatively arrange the drilling position 3 when the rock layer 1 to be excavated is a rock layer inclined to the left side of the rock layer surface, accurately determine the distribution of soluble rock strata such as tunnel limestone, and find out the water volume in front of the heading face, thereby playing the role of early targeted water discharge, avoiding adverse geological conditions such as water gushing and mud bursting, ensuring tunnel construction safety, improving survey accuracy, reducing the number of drillings while ensuring continuous exploration, and greatly reducing survey costs and saving survey cycles.

[0103] Case 2

[0104] This case is a case where the rock layer 1 to be excavated is a rock layer with a rock layer surface inclined to the right, such as Fig.11 As shown in the figure, the ratio η of the longitudinal scale to the transverse scale in the project of this case is 1. The lithology of the tunnels in this project is mostly hard rocks such as granite and calcareous sandstone. There are alteration zones and compression and crushing zones in some granite strata. The integrity of the surrounding rock is generally good, and the shield machine excavation method is adopted.

[0105] The compass measured that the rock formation 1 to be excavated at the tunnel face position is N35°W, the rock formation dip azimuth is 40°, the rock formation true dip angle γ is 40°, and the direction of the tunnel axis is N80°W. According to the direction of the tunnel axis, the direction of the tunnel face projection on the horizontal plane can be obtained as N10°E, so the angle between the rock formation direction and the tunnel face μ=10°+35°=45°. Based on the above situation, it is comprehensively judged that the rock formation 1 to be excavated in this project is a rock formation with a rightward tilt. Therefore, two boreholes are arranged outside the contour line 2 of the tunnel face, and the azimuths of the two borehole positions 3 are β3 and β4 respectively. The calculation formulas for β3 and β4 are as follows:

[0106] β3=90°-α

[0107] β4=270°-α

[0108] α=arctan(ηtanγsinμ)

[0109] Among them, η=1, γ=40°, and μ=45°.

[0110] Therefore, α=arctan(1×tan40°×sin45°)=30°.

[0111] Therefore, β3=90°-α=90°-30°=60°, β4=270°-α=270°-30°=240°.

[0112] According to the above calculation results, a borehole is arranged at 3m to 5m outside the contour line 2 of the tunnel face, and at azimuths of 60° and 240° respectively. After horizontal directional drilling construction, the borehole with an azimuth of 60° revealed that there was an alteration zone 5m to 15m in front of the tunnel face. The surrounding rock was broken and it was extremely easy to get stuck, causing landslides and delayed landslides, which were extremely risky. The borehole with an azimuth of 240° revealed calcareous sandstone with good surrounding rock integrity. According to the occurrence of the rock formation, the current tunnel face and the distribution position of the alteration zone in front are inferred. Subsequently, grouting is used to timely reinforce the alteration zone and other surrounding rock broken areas. When the surrounding rock strength reaches the requirements, the shield machine is used to excavate and smoothly pass through the alteration zone and other surrounding rock broken zones in this section. There are no geological disasters such as stuck machines, landslides or delayed landslides.

[0113] Through a tunnel horizontal directional drilling arrangement method applied in the present invention, the drilling position 3 can be quantitatively arranged when the rock layer 1 to be excavated is a rock layer inclined to the right side of the rock layer surface, thereby improving the survey accuracy, accurately detecting the surrounding rock fragmentation areas such as the alteration zone in front of the heading face, avoiding geological disasters such as machine jams, landslides or delayed landslides, and improving construction efficiency; at the same time, while ensuring continuous exploration, the number of drillings is reduced, the survey cost is greatly reduced, and the survey cycle is saved.

[0114] The present application can be used for drilling arrangement of horizontal directional drilling of tunnels (holes) in mountainous areas such as railways, highways or hydropower stations.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for arranging horizontal directional drilling holes in a tunnel, characterized in that: The following steps are involved: S1: Select tunnel excavation technology; S2: When the drilling and blasting method is used for excavation, the drilling position (3) of the horizontal directional drilling is arranged within the contour line (2) of the tunnel face; When excavation is carried out by using a roadheader or a shield method, the drilling position (3) of the horizontal directional drilling is arranged outside the contour line (2) of the tunnel face, and according to the occurrence of the rock formation, the rock formation to be excavated (1) is divided into five categories: rock formations with a rock formation inclination consistent with the tunnel axis direction, rock formations with a rock formation plane parallel to the horizontal plane, rock formations with a rock formation plane perpendicular to the horizontal plane, rock formations with a rock formation plane inclined to the left, and rock formations with a rock formation plane inclined to the right; When the rock layer (1) to be excavated is a rock layer whose inclination is consistent with the tunnel axis direction, a borehole is arranged outside the contour line (2) of the tunnel face, and the azimuth angle of the borehole position (3) is 90° or 270°; When the rock layer (1) to be excavated is a rock layer whose rock layer surface is parallel to the horizontal plane, two boreholes are arranged outside the contour line (2) of the tunnel face, and the azimuth angles of the two borehole positions (3) are 0° and 180° respectively; When the rock layer (1) to be excavated is a rock layer whose rock layer surface is perpendicular to the horizontal plane, a borehole is arranged outside the contour line (2) of the tunnel face, and the azimuth angle of the borehole position (3) is 90° or 270°; When the rock layer (1) to be excavated is a rock layer inclined to the left, two boreholes are arranged outside the contour line (2) of the tunnel face, and the two borehole positions (3) are respectively located in a first area (5) and a second area (6) outside the contour line (2) of the tunnel face; When the rock layer (1) to be excavated is a rock layer inclined to the right, two drill holes are arranged outside the contour line (2) of the tunnel face, and the two drill hole positions (3) are respectively located in a third area (7) and a fourth area (8) outside the contour line (2) of the tunnel face.

2. A method for arranging horizontal directional drilling holes in a tunnel according to claim 1, characterized in that: In step S2, when the drilling and blasting method is used for excavation, the drilling position (3) of the horizontal directional drilling is arranged in a circular area with a central radius of 2 meters on the tunnel face.

3. A method for arranging horizontal directional drilling holes in a tunnel according to claim 2, characterized in that: In step S2, when the drilling and blasting method is used for excavation, the drilling position (3) of the horizontal directional drilling is arranged at the center of the tunnel face.

4. The method for arranging horizontal directional drilling holes in a tunnel according to claim 1, characterized in that: In step S2, when the rock layer (1) to be excavated is a rock layer inclined to the left, the azimuths of the two drilling positions (3) are β1 and β2 respectively, and the calculation formulas of β1 and β2 are as follows: β1＝270°+α β2＝90°+α α=arctan(ηtanγsinμ) Wherein, β1 represents the azimuth when the drilling position (3) is located at the upper left of the tunnel; β2 represents the azimuth when the drilling position (3) is located at the lower right of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, wherein the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, i.e., the depth direction of the rock formation, and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ represents the true inclination of the rock formation; and μ represents the angle between the rock formation strike and the tunnel face.

5. The method for arranging horizontal directional drilling holes in a tunnel according to claim 1, characterized in that: In step S2, when the rock layer (1) to be excavated is a rock layer inclined to the right, the azimuths of the two drilling positions (3) are β3 and β4 respectively, and the calculation formulas of β3 and β4 are as follows: β3＝90°-α β4＝270°-α α=arctan(ηtanγsinμ) Wherein, β3 represents the azimuth when the drilling position (3) is located at the upper right of the tunnel; β4 represents the azimuth when the drilling position (3) is located at the lower left of the tunnel; α represents the apparent inclination of the rock formation; η represents the ratio of the longitudinal scale to the transverse scale, wherein the longitudinal scale represents the proportional relationship between the length in the vertical direction on the profile, i.e., the depth direction of the rock formation, and the vertical length of the actual geological body, and the transverse scale represents the proportional relationship between the length in the horizontal direction on the profile and the horizontal length of the actual geological body; γ represents the true inclination of the rock formation; and μ represents the angle between the rock formation strike and the tunnel face.

6. A method for arranging horizontal directional drilling holes in a tunnel according to any one of claims 1 to 5, characterized in that: In the step S2, when excavation is carried out using a tunnel boring machine or a shield method, the drilling position (3) of the horizontal directional drilling is arranged at a position 1 to 5 meters outside the contour line (2) of the tunnel face.

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