Hole entering method for gently-inclined deep and thick soil slope near-mountain tunnel construction

Abstract

The invention provides a gently inclined deep soil slope hillside tunnel construction entering method which comprises the steps that primary excavation is conducted on a gently inclined slope, a grouting platform and a primary excavation slope face are formed, and the grouting platform is flush with the top of a preset tunnel structure; a primary support is arranged on the primary excavation side slope face, a plurality of grouting holes are formed in a grouting platform, and grouting is conducted in the grouting holes; after the slurry in the grouting hole is solidified, secondary excavation is conducted on the grouting platform, and a secondary excavation side slope face is formed; a tunnel outer side wall is constructed on the secondary excavation side slope face, and a toe board is constructed on the position, close to the bottom of the tunnel outer side wall, of the outer wall of the tunnel outer side wall; entering a tunnel according to the planned first excavation area, and constructing an inner side wall of the tunnel; the remaining second excavation area between the tunnel inner side wall and the tunnel outer side wall is excavated, and a tunnel bottom plate is constructed; and the outer side of the outer side wall of the tunnel is backfilled with excavation materials generated by excavation, and a backfilled inclined slope is formed. By means of the method, the safety and reliability of hole entering and hole forming in the soil body are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of tunnel engineering, in particular to a method for construction of a tunnel in a gently inclined deep soil slope. BACKGROUND

[0002] With the updating of construction equipment, for some complex terrain areas, the construction is carried out by excavating a tunnel, however, in the construction process, it is inevitable to encounter the situation of a gently inclined soil slope tunnel into the tunnel, at present, in the traditional construction process of a gently inclined soil slope tunnel into the tunnel, when the thickness of the covering layer along the tunnel axis is thin, the surface covering layer is stripped, and the exposed rock is used to enter the tunnel, but when the covering layer extends along the tunnel axis with a long thickness, the stripping work is large, and the original vegetation is damaged, and in the construction process, due to the gentle lateral slope (generally ≤1:2) of the slope perpendicular to the tunnel axis, the tunnel axis is close to the outside, which causes the thickness of the top and lateral covering layer of the tunnel to not meet the 2-3 times tunnel diameter condition for tunneling, and direct tunneling is easy to cause eccentric pressure and collapse, thereby causing serious construction accidents. SUMMARY

[0003] In order to solve the problem that in the existing construction process of a mountain tunnel, when the covering layer is long, the interval of stripping the surface covering layer to damage the original vegetation is large, and the thickness of the top and lateral covering layer of the tunnel after stripping is thin, which is easy to cause collapse, the present application provides a method for construction of a tunnel in a gently inclined deep soil slope, which improves the reliability and safety of the construction of a mountain tunnel with eccentric pressure.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: The present application provides a method for construction of a tunnel in a gently inclined deep soil slope, comprising the following steps: A first excavation is carried out on the gently inclined slope to form a grouting platform and a first excavation slope surface, and the grouting platform is flush with the top of the preset tunnel structure; an initial support is arranged on the first excavation slope surface, a plurality of grouting holes are formed on the grouting platform, and grouting is carried out in the grouting holes; After the grouting material in the grouting hole is solidified, the grouting platform is secondly excavated to the preset second excavation contour line to form a second excavation slope surface; an outer side wall of the tunnel is constructed on the second excavation slope surface, and a toe plate is constructed on the outer wall of the outer side wall of the tunnel near the bottom thereof; According to the planned first excavation area, the tunnel is entered, and an inner side wall of the tunnel is constructed; a second excavation area remaining between the inner side wall of the tunnel and the outer side wall of the tunnel is excavated, and a tunnel bottom plate is constructed; The excavation material generated by the first excavation and the second excavation is backfilled on the outside of the outer side wall of the tunnel to form a backfilled inclined slope with a slope ratio of 1:1.2-1:1.5.

[0005] Preferably, the slope ratio of the primary excavation slope surface is 1:1.2~1:1.5.

[0006] Preferably, the setting of the initial support on the primary excavation slope surface comprises: setting two rows of lock-hole anchor piles on the primary excavation slope surface near the top of the slope; setting multiple rows of full-length adhesive anchor rods in the area between the anchor piles and the grouting platform on the primary excavation slope surface; wherein the full-length adhesive anchor rods and the lock-hole anchor piles are both perpendicular to the primary excavation slope surface.

[0007] Preferably, the full-length adhesive anchor rod is a self-feeding hollow grouting anchor rod, the length of the full-length adhesive anchor rod is 4.5m, and the diameter is 25mm, and the length of the lock-hole anchor pile is 9.0m.

[0008] Preferably, the multiple grouting holes on the grouting platform comprise: a plurality of rows of vertical grouting holes are set on the upper plane of the grouting platform with a spacing of 1.0m, and the spacing between adjacent two vertical grouting holes in each row of vertical grouting holes is 1.5m; the vertical grouting holes are perpendicular to the upper plane of the grouting platform; a plurality of radial grouting holes are arranged radially at the junction of the grouting platform and the primary excavation slope surface, and the included angle between adjacent two radial grouting holes is 15°.

[0009] Preferably, the construction of the tunnel outer side wall on the secondary excavation slope surface and the construction of the toe plate on the outer wall of the tunnel outer side wall near the bottom thereof comprise: constructing a tunnel outer side wall formwork on the slope surface of the secondary excavation slope surface at the planned position of the tunnel; laying a plastic film in the tunnel outer side wall formwork; grouting and solidifying in the pouring formwork to obtain the tunnel outer side wall; constructing a toe plate formwork on the outer wall of the tunnel outer side wall near the bottom end surface thereof, grouting and solidifying in the toe plate formwork to obtain the toe plate with a thickness of 0.4m~0.5m.

[0010] Preferably, the in-tunnel construction according to the planned first excavation area and the construction of the tunnel inner side wall comprise: setting a demarcation line in the planned tunnel interior construction area to divide the tunnel interior construction area into a first excavation area and a second excavation area; On the side of the first excavation area, and at a position outside the construction area inside the tunnel, construct pipe roofs and advance grouting pipes, and inject grout into the pipe roofs and advance grouting pipes. After the grout solidifies, construct and support the first excavation area. After the first excavation area is excavated, the formwork for the inner sidewall of the tunnel is constructed in the supported area, and then poured and consolidated to complete the construction of the inner sidewall of the tunnel.

[0011] Preferably, the boundary line between the second excavation area and the first excavation area forms an angle of 70° to 75° with the bottom surface of the tunnel, and the starting point of the boundary line is the center point of the planned bottom end face of the tunnel.

[0012] Preferably, before constructing the tunnel floor slab, a toothed wall with a height of 0.5m is constructed on the inner sidewall of the tunnel near the second excavation area.

[0013] Preferably, when excavating on the gently sloping slope, a passive protective net should also be installed at the top of the gently sloping slope.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes a method for tunnel construction on gently sloping, deep soil slopes. This method improves the overall stability and construction safety of the gently sloping slope and tunnel project through phased excavation and a structured support system. Specifically, the initial support set up immediately after the first excavation effectively controls slope deformation. The grouting platform forms a continuous consolidated body by injecting grout through grouting holes, which not only strengthens the internal structure of the soil and rock mass but also constructs a seepage prevention curtain, reduces the erosive effect of groundwater seepage pressure on the slope, improves the slope's resistance to sliding, enhances the safety and reliability of tunnel entry and tunnel completion within the soil, accelerates the construction progress, and shortens the construction period.

[0015] Furthermore, in this method, when the secondary excavation reaches the preset outline, the grouting platform has already formed a stable bearing platform, reducing the disturbance range of the surrounding rock mass caused by the secondary excavation. The combined structure of the tunnel's outer wall and toe slab transfers the sidewall load to the deep stable rock layer through the toe slab, forming a composite stress system. This effectively solves the problem of stress concentration at the bottom of the traditional sidewall and the step-by-step construction process of the inner sidewall and bottom slab. By using a space-for-time strategy, the stress of the tunnel structure is gradually transferred to the intact bedrock, avoiding the sudden stress change caused by full-section excavation.

[0016] Furthermore, this method uses 1:1.2 to 1:1.5 inclined slopes formed by backfilling excavated material to reduce the loss of backfill material and decrease the amount of waste material in the project. Attached Figure Description

[0017] Figure 1This invention provides a schematic diagram of the original gently sloping slope surface in a method for tunnel construction on a gently sloping, deep soil slope. Figure 2 This invention provides a schematic diagram of the method for tunnel construction on a gently sloping, deep soil slope, following the initial excavation. Figure 3 This invention provides a schematic diagram of the secondary excavation process in a method for constructing a tunnel on a gently sloping, deep soil slope near a mountain. Figure 4 This invention provides a schematic diagram of the backfilling process after excavation in a method for constructing a tunnel on a gently sloping, deep soil slope along a mountainside. Figure 5 This invention provides a schematic diagram of the construction of the toothed wall in a method for constructing a tunnel on a gently sloping, deep soil slope. In the attached diagram: 1. Tunnel structure; 2. Original gently sloping slope; 3. Toe slab; 4. Primary excavation slope; 5. Grouting platform; 6. Grouting hole; 7. Tooth wall; 8. Secondary excavation slope; 9. Outer wall of the tunnel; 10. Pipe roof and pre-grouting small guide pipe; 11. Inner wall of the tunnel; 12. Tunnel floor slab; 13. First excavation zone; 14. Second excavation zone; 15. Locking anchor pile; 16. Full-length bonded anchor; 17. Boundary line; 18. Backfilled sloping slope. Detailed Implementation

[0018] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] In this implementation, to reduce construction difficulty, the tunnel is divided into three parts for construction: the inner tunnel wall 11, the outer tunnel wall 9, and the tunnel floor slab 12. The tunnel floor slab 12 is not the bottom of the entire tunnel structure 1, but rather the bottom end face of the second excavation zone defined during construction, with a length equal to half the width of the bottom of the entire tunnel structure 1. The inner tunnel wall 11 comprises three parts: a semi-arched section representing half of the top half of the tunnel structure 1, a vertical wall within the tunnel structure 1 away from the slope, and a floor slab at the bottom of the tunnel structure 1, with a length equal to half the width of the bottom of the tunnel structure 1. The outer tunnel wall 9 comprises two parts: a semi-arched section representing the other half of the top half of the tunnel structure 1, and a vertical wall outside the tunnel structure 1 near the slope. This invention proposes a method for tunnel construction on gently sloping, deep soil slopes, with the specific construction process as follows: Figures 1-5 As shown, it includes the following steps: An excavation is carried out on the gently sloping slope to form a grouting platform 5 and a primary excavation slope surface 4, as follows: Figure 2As shown, the grouting platform 5 is flush with the top of the pre-set tunnel structure 1; and initial support is set on the excavated slope surface 4 to reduce exposure time and avoid slope instability due to excessive stress release; multiple grouting holes 6 are opened on the grouting platform and grout is injected into the grouting holes 6; by setting grouting holes 6 on the grouting platform and injecting grout, the cracks in the rock and soil are effectively filled to form an integral reinforcement layer, improve the shear strength and impermeability of the slope, and reduce the risk of landslide.

[0024] After the grout in the grouting hole 6 has solidified, the grouting platform 5 is excavated again to the preset secondary excavation outline, forming the secondary excavation slope surface 8, as shown. Figure 3 As shown, secondary excavation to the preset outline can precisely control the slope shape, reduce over-excavation and under-excavation, and further optimize the stress state of the slope; the tunnel outer wall 9 is constructed on the secondary excavation slope surface 8. The initial support and the tunnel outer wall 9 after secondary excavation form a composite support structure, which effectively disperses the load and improves the safety of construction. Toe plate 3 is constructed on the outer wall of the tunnel outer wall 9 near its bottom to improve the compressive strength of the tunnel outer wall 9. According to the planned first excavation zone 13, the tunnel will be entered, and the inner sidewall 11 will be constructed. The remaining second excavation zone 14 between the inner sidewall 11 and the outer sidewall 9 will be excavated, and the tunnel floor slab 12 will be constructed. Figure 4 As shown, excavation in sections reduces construction interference and shortens the construction period; The excavated material generated during backfilling on the outer side of the tunnel outer wall 9 forms a backfill sloping slope 18 with a gradient of 1:1.2 to 1:1.5. The backfill material uses the excavated soil and rock, reducing the cost of transporting waste. At the same time, the gentle slope of 1:1.2 to 1:1.5 reduces the difficulty of backfill compaction and improves construction efficiency.

[0025] In this embodiment, the slope ratio of the original gently sloping slope 2 is generally less than 1:2, such as... Figure 1 As shown, a tunnel structure 1 is planned on the original gently sloping slope 2. When planning the tunnel structure 1, it is necessary to plan the height of the tunnel structure 1 from the original gently sloping slope 2, the thickness of the tunnel top to the original gently sloping slope 2, and the width of the tunnel structure 1.

[0026] When excavating on a gently sloping slope, a passive protective net is first installed at the top of the slope to intercept falling debris and other debris, thus improving construction safety. On the original gently sloping slope surface 2, construction equipment is used to excavate, removing the surface layer to form a grouting platform 5 and a primary excavation slope surface 4 with a slope ratio of 1:1.2 to 1:1.5. Figure 2 As shown.

[0027] like Figure 2As shown, the initial support for the excavated slope 4 includes: Two rows of interlocking anchor piles 15 are installed near the top of the primary excavation slope 4 at a spacing of 2.0m. The length of each interlocking anchor pile 15 is 9.0m, and each interlocking anchor pile 15 is a bundle of three steel bars with a diameter of 28 mm. In the area between the interlocking anchor piles 15 and the grouting platform 5 on the primary excavation slope 4, multiple rows of full-length bonded anchor rods 16 are installed at a spacing of 2.0m. The length of each full-length bonded anchor rod 16 is 4.5m, and the diameter is 25mm. The full-length bonded anchor rods 16 and the interlocking anchor piles 15 are perpendicular to the primary excavation slope 4. The full-length bonded anchor rods 16 are self-propelled hollow grouting anchor rods.

[0028] like Figure 2 As shown, multiple grouting holes 6 are opened on the grouting platform 5, including: Multiple rows of vertical grouting holes are set at 1.0m intervals on the upper surface of the grouting platform 5. The distance between two adjacent vertical grouting holes in each row is 1.5m. The vertical grouting holes are perpendicular to the upper surface of the grouting platform 5. At the junction of the grouting platform 5 and the primary excavation slope 4, multiple radial grouting holes are set radially. The included angle between two adjacent radial grouting holes is 15°. The maximum depth of the vertical grouting holes and the radial grouting holes is 1.0m deeper than the elevation of the tunnel floor 12.

[0029] like Figure 3 As shown, the construction of the tunnel outer wall 9 on the secondary excavation slope 8, and the construction of the toe plate 3 on the outer wall of the tunnel outer wall 9 near its bottom, includes: On the slope surface 8 of the secondary excavation, at the planned location of the tunnel structure 1, construct the outer wall formwork of the tunnel. Lay a plastic film inside the outer wall formwork and apply a release agent to the plastic film to facilitate later demolding and separation from the lining. Pour concrete into the formwork and solidify it to obtain the outer wall 9 of the tunnel. Construct a toe plate formwork near the bottom end face of the outer wall 9 of the tunnel. Pour concrete into the toe plate formwork and solidify it to obtain a toe plate 3 with a thickness of 0.4m to 0.5m. Concrete haunches are constructed at the connection between the toe plate 3 and the outer wall 9 of the tunnel to improve the moment transmission conditions of the outer wall 9 of the tunnel and reduce stress concentration.

[0030] like Figure 3 and Figure 4As shown, the tunnel is constructed according to the planned first excavation zone 13, including the construction of the inner sidewall 11 of the tunnel. This includes setting a boundary line 17 within the planned construction area of ​​the tunnel structure 1 to divide the construction area of ​​the tunnel structure 1 into the first excavation zone 13 and the second excavation zone 14. The boundary line 17 between the second excavation zone 14 and the first excavation zone 13 forms an angle of 70° to 75° with the bottom surface of the tunnel structure 1, and the center point of the bottom end face of the planned tunnel structure 1 is taken as the starting point of the boundary line 17. Multiple pipe roofs and pre-grouting small guide pipes 10 are constructed on the side of the first excavation zone 13, located outside the construction area inside the tunnel structure 1. The pipe roofs and pre-grouting small guide pipes 10 are arranged along the excavation direction of the tunnel structure 1, and grout is injected into the pipe roofs and pre-grouting small guide pipes 10. After the grout solidifies, the first excavation zone 13 is constructed and supported. After the first excavation zone 13 is excavated, the tunnel inner wall formwork is constructed in the supported area, concrete is poured and solidified, and the tunnel inner wall is completed. After the construction of wall 11, the excavation of the second excavation zone 14 is carried out. After the completion of the second excavation zone 14, a tunnel floor slab formwork is set up in the second excavation zone 14 between the outer tunnel wall 9 and the inner tunnel wall 11. Concrete is poured into the tunnel floor slab formwork and solidified, completing the construction of tunnel structure 1. Before constructing the tunnel floor slab 12, a toothed wall 7 with a height of 0.5m is constructed on the inner tunnel wall 11 near the second excavation zone 14 to restrict the displacement of the inner tunnel wall 11. Figure 5 As shown, the slope ratio of the inclined surfaces in the toothed wall 7 is 1:0.7, and the width at the bottom is 0.3.

[0031] After the tunnel structure 1 is completed, the excavated material is used to backfill the outside of the tunnel outer wall 9, backfilling to the original gently sloping slope 2. Then, backfilling is carried out again on the original gently sloping slope 2 after backfilling, forming a backfilled inclined slope 18 with a slope ratio of 1:1.2 to 1:1.5.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for tunnel construction and entry into a gently sloping, deep soil slope along a mountainside, characterized in that, Includes the following steps: An excavation is carried out on a gently sloping slope to form a grouting platform and a primary excavation slope surface, with the grouting platform flush with the top of the pre-designed tunnel structure; initial support is set on the primary excavation slope surface, multiple grouting holes are opened on the grouting platform, and grout is injected into the grouting holes; After the grout in the grouting hole solidifies, the grouting platform is excavated again to the preset secondary excavation outline to form a secondary excavation slope. The outer wall of the tunnel is constructed on the secondary excavation slope, and a toe plate is constructed on the outer wall of the tunnel near its bottom. Enter the tunnel according to the first excavation zone as planned, and construct the inner sidewall of the tunnel; excavate the remaining second excavation zone between the inner sidewall and the outer sidewall of the tunnel, and construct the tunnel floor slab; The excavated material from the first and second excavations is backfilled on the outer side of the outer wall of the tunnel to form a backfilled inclined slope with a slope ratio of 1:1.2 to 1:1.

5.

2. The method for tunnel construction on a gently sloping, deep soil slope as described in claim 1, characterized in that, The slope ratio of the excavated slope surface is 1:1.2 to 1:1.

5.

3. The method for tunnel construction on a gently sloping, deep soil slope as described in claim 1, characterized in that, The initial support structure installed on the slope surface during the primary excavation includes: Two rows of interlocking anchor piles are installed on the slope surface near the top of the slope during the primary excavation. Multiple rows of full-length bonded anchor bolts are installed in the area between the lock anchor pile and the grouting platform on the primary excavation slope surface; Both the full-length bonded anchor bolt and the lock anchor pile are perpendicular to the primary excavation slope surface.

4. The method for tunnel construction on a gently sloping, deep soil slope as described in claim 3, characterized in that, The fully bonded anchor bolt is a self-drilling hollow grouting anchor bolt, with a length of 4.5m and a diameter of 25mm. The length of the interlocking anchor pile is 9.0m.

5. The method for tunnel construction and entry into a gently sloping, deep soil slope along a mountainside according to claim 1, characterized in that, Multiple grouting holes are opened on the grouting platform, including: Multiple rows of vertical grouting holes are arranged at 1.0m intervals on the upper surface of the grouting platform, with a 1.5m distance between adjacent vertical grouting holes in each row; the vertical grouting holes are perpendicular to the upper surface of the grouting platform. At the junction of the grouting platform and the primary excavation slope, multiple radial grouting holes are radially arranged, with an included angle of 15° between two adjacent radial grouting holes.

6. The method for tunnel construction and entry into a gently sloping, deep soil slope along a mountainside according to claim 1, characterized in that, Constructing the outer wall of the tunnel on the secondary excavation slope, and constructing a toe slab on the outer wall of the tunnel near its bottom, includes: On the slope surface of the secondary excavation, at the planned location of the tunnel, construct the outer wall formwork of the tunnel; lay a plastic film inside the outer wall formwork of the tunnel; Grouting is injected into the casting template and solidified to obtain the outer wall of the tunnel; A toe slab template is constructed on the outer wall of the tunnel near its bottom end face. Grout is injected into the toe slab template and solidified to obtain a toe slab with a thickness of 0.4m to 0.5m.

7. The method for tunnel construction and entry into a gently sloping, deep soil slope along a mountainside according to claim 1, characterized in that, The construction of the tunnel inner sidewalls, according to the planned first excavation zone, includes: A dividing line is set within the planned construction area inside the tunnel to divide the construction area inside the tunnel into a first excavation zone and a second excavation zone. On the side of the first excavation area, and at a position outside the construction area inside the tunnel, construct pipe roofs and advance grouting pipes, and inject grout into the pipe roofs and advance grouting pipes. After the grout solidifies, construct and support the first excavation area. After the first excavation area is excavated, the formwork for the inner sidewall of the tunnel is constructed in the supported area, and then poured and consolidated to complete the construction of the inner sidewall of the tunnel.

8. The method for tunnel construction on a gently sloping, deep soil slope as described in claim 7, characterized in that, The boundary line between the second excavation area and the first excavation area forms an angle of 70° to 75° with the bottom surface of the tunnel, and the center point of the planned bottom end face of the tunnel is taken as the starting point of the boundary line.

9. The method for tunnel construction and entry into a gently sloping, deep soil slope tunnel according to claim 1, characterized in that, Before constructing the tunnel floor slab, a toothed wall with a height of 0.5m is constructed on the inner sidewall of the tunnel near the second excavation area.

10. The method for tunnel construction and entry into a gently sloping, deep soil slope along a mountainside according to claim 1, characterized in that, When excavating on the gently sloping slope, a passive protective net must also be installed at the top of the gently sloping slope.

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