Zero-excavation tunnel-entering construction method for high-speed rail tunnel and tunnel portal supporting steel frame structure

Abstract

The invention discloses a zero-excavation tunnel-entering construction method for a high-speed rail tunnel and a tunnel portal support steel frame structure, and belongs to the technical field of tunnel construction. The method aims at reducing the influence on the original ecological environment, enabling construction to be simple and rapid, and improving the tunnel entering efficiency. According to the technical scheme, the zero-excavation tunnel-entering construction method for the high-speed rail tunnel comprises the following steps that S1, dangerous rock falling treatment is conducted; s2, reinforcing an upward slope groove; s3, a guide groove and a guide frame are constructed; s4, construction of a double-layer small guide pipe advance support; s5, constructing a temporary shed tunnel; s6, hole entering construction is carried out; and S7, inverted arch support ring forming. The tunnel portal support steel frame structure comprises a guide frame, a forepoling structure and a temporary shed tunnel steel frame, the forepoling structure is driven into a soil layer through the guide frame, and the temporary shed tunnel steel frame is aligned with a first profile steel frame in the guide frame. The method is used for zero-excavation hole-entering construction of the high-speed rail tunnel.

Description

Technical Field

[0001] The invention discloses a high-speed railway tunnel zero-excavation tunnel construction method and a tunnel portal support steel frame structure, belonging to the technical field of tunnel construction. Background Art

[0002] With the continuous development of China's high-speed railway construction, railway construction has gradually extended to ecologically sensitive and fragile areas, and even passed through national environmental protection areas. When crossing such areas, it is required to avoid damaging the surrounding ecological environment as much as possible. In view of the high environmental protection requirements in the above-mentioned tunnel construction, the traditional brush slope support construction is adopted, that is, the "side slope excavation protection-guide wall-advanced large pipe shed" construction method.

[0003] In addition, when the tunnel entrance is located in a steep mountain slope area, the slope brushing process will cause damage to the mountain forest and soil structure, destroying the original balance of the mountain. The surface of the soil will be stripped off, causing the soil to become loose. During heavy rainfall, rainwater will seep in, increasing the downward force of the slope, which can easily lead to safety accidents such as instability of the side slope induced by geological disasters such as rock piles, landslides, collapses, and falling dangerous rocks.

[0004] Traditional slope support requires extensive pre-entry protection of the tunnel entrance, which increases the excavation area outside the lining contour. During tunnel entry construction, taking into account the geological conditions of the tunnel entry, it is particularly important to achieve "zero" excavation outside the lining contour, minimize damage to the original slope vegetation, improve tunnel entry efficiency, and shorten construction time. Summary of the Invention

[0005] In view of the deficiency in the existing technology that large excavation and large brushing cause great damage to the side slope, the purpose of the present invention is to provide a high-speed railway tunnel zero excavation construction method and a tunnel portal support steel frame structure, which has little impact on the original ecological environment, is simple and fast to construct, and improves the efficiency of tunnel entry.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a high-speed railway tunnel zero-excavation construction method, comprising the following steps: S1, Dangerous rockfall treatment: Before construction, clear the area within the tunnel entrance and treat the dangerous rockfall on the tunnel roof; S2, back slope reinforcement: The tunnel excavation contour line is measured and laid out on the back slope surface. Mortar anchors are used within 1-1.5m outside the excavation contour line, and reinforced mesh and shotcrete are installed. S3, construction of guide groove and guide frame: construct a guide groove along the outer side of the excavation surface contour line, and fix the guide frame in the guide groove. The guide frame includes a first steel frame and a second steel frame arranged inside and outside. A plurality of inner directional tubes are welded between the first steel frame and the second steel frame, and a plurality of outer directional tubes are welded on the outer arc surface of the second steel frame. S4, double-layer small pipe advance support construction: driving an inner layer small pipe and an outer layer small pipe into the soil layer through the inner layer directional pipe and the outer layer directional pipe, and grouting to reinforce them for advance support; S5, temporary shed tunnel construction: align and arrange multiple third-shaped steel frames side by side with the first-shaped steel frames, connect the multiple third-shaped steel frames with multiple longitudinal connecting steel bars, and set one or two locking anchor pipes at the two feet of each third-shaped steel frame. After the third-shaped steel frames are erected, spray concrete to form the temporary shed tunnel; S6, tunnel construction: Use non-blasting or controlled weak blasting excavation methods to enter the tunnel for excavation construction; S7, inverted arch support ring: After 15m into the tunnel, the initial support of the inverted arch is constructed to form a ring.

[0007] Preferably, in S2, the diameter of the mortar anchor is φ22 mm, the length is 4 m, the spacing is 1 m×1 m, the diameter of the steel mesh is φ8 mm, the grid spacing is 20 cm×20 cm, and the sprayed C25 concrete is 10 cm thick.

[0008] Preferably, in S3, the first steel frame and the second steel frame are both made of I22a I-steel, the diameters of the inner directional tube and the outer directional tube are both φ76 mm, and the number of each is 50.

[0009] Preferably, in S4, the diameter of the inner layer small tube and the outer layer small tube are both φ42 mm, the length is both 6 m, and the number is 50.

[0010] Preferably, in said S5, the third steel frame is made of I20b I-steel, the number is 6, the spacing between adjacent third steel frames is 0.5m, the diameter of the longitudinal connecting steel bars is φ22mm, the spacing is 1m, the diameter of the locking foot anchor pipe is φ42mm, the length is 5m, the concrete used for spraying is C30 concrete, and the wall thickness after spraying is completed is 30cm.

[0011] The tunnel portal support steel frame structure includes a guide frame, an advance support structure and a temporary shed steel frame. The guide frame includes a first steel frame and a second steel frame arranged inside and outside. A plurality of inner directional tubes are welded between the first steel frame and the second steel frame, and a plurality of outer directional tubes are welded on the outer arc surface of the second steel frame. The advanced support structure includes an inner layer of small pipes and an outer layer of small pipes. The number of the inner layer of small pipes is the same as that of the inner layer of directional pipes. The inner layer of small pipes is correspondingly driven through the inner layer of directional pipes and driven into the soil layer. The number of the outer layer of small pipes is the same as that of the outer layer of directional pipes. The outer layer of small pipes is correspondingly driven through the outer layer of directional pipes and driven into the soil layer. The temporary shed steel frame includes multiple third-section steel frames, which are aligned with and arranged in parallel with the first-section steel frames. The multiple third-section steel frames are connected by multiple longitudinal connecting steel bars, and each of the two feet of each third-section steel frame is provided with 1 or 2 locking foot anchor pipes.

[0012] Preferably, the first steel frame and the second steel frame are both I22a I-steel, the diameters of the inner directional tube and the outer directional tube are both φ76mm, and the number of each is 50.

[0013] Preferably, the inner layer small tubes and the outer layer small tubes have a diameter of φ42 mm, a length of 6 m, and a number of 50 tubes.

[0014] Preferably, the third steel frame is I20b I-beam, the number is 6, the spacing between adjacent third steel frames is 0.5m, the diameter of the longitudinal connecting steel bars is φ22mm, the spacing is 1m, the diameter of the locking foot anchor pipe is φ42mm, and the length is 5m.

[0015] Compared with the prior art, the present invention has the following beneficial effects.

[0016] 1. The present invention adopts the support form and structure of slope reinforcement + guide frame + double-layer small guide tube + temporary shed, which realizes "zero" excavation outside the lining contour line, avoids large-scale excavation and brushing of the mountain, reduces the excavation surface of the tunnel entrance, and greatly prevents the damage to the vegetation on the back slope beside the tunnel. The vegetation around the tunnel entrance is properly protected, and the original ecological landscape is maintained. At the same time, the exposure time of the tunnel entrance grooving is shortened, the amount of tunnel entrance protection work is controlled, which is beneficial to the stability of the back slope. The tunnel construction time can be shortened by about 10 days compared with the traditional tunnel construction method, which fully improves the tunnel entry efficiency.

[0017] 3. The construction process and support structure of the present invention are simple, and the required equipment and materials are easy to purchase, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments.

[0019] Figure 1 This is a flow chart of the zero-excavation construction method for a high-speed railway tunnel according to the present invention.

[0020] Figure 2It is a structural schematic diagram of the tunnel portal support steel frame structure of the present invention.

[0021] Figure 3 It is a front view of the guide frame of the present invention.

[0022] Figure 4 It is a side view of the tunnel entry construction in the present invention.

[0023] In the figure: 1 is the guide frame, 11 is the first steel frame, 12 is the second steel frame, 13 is the inner directional pipe, 14 is the outer directional pipe, 2 is the advanced support structure, 21 is the inner small guide tube, 22 is the outer small guide tube, 3 is the temporary shed steel frame, 31 is the third steel frame, 32 is the longitudinal connecting steel bar, 33 is the locking foot anchor pipe, 4 is the dangerous rock fall, 5 is the excavation surface contour line, 6 is the guide groove, 7 is the temporary shed, 8 is the slope reinforcement line, and 9 is the upslope surface. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] The present invention provides the following examples.

[0026] like Figure 1 、 Figure 4 As shown, the zero-excavation construction method for high-speed railway tunnels of the present invention comprises the following steps: S1, Dangerous rockfall treatment: Before construction, clear the area within the tunnel entrance and treat the dangerous rockfall 4 on the tunnel roof to ensure that there is no risk of rockfall injury during subsequent construction. S2, backslope groove reinforcement: On the backslope surface 9, the tunnel excavation surface contour line 5 is measured and laid out, and mortar anchor rods are used within the range of 1-1.5m outside the excavation surface contour line 5, and steel mesh is hung and concrete is sprayed. Before reinforcement, the groove reinforcement line 8 can be marked according to the reinforcement range, and the groove reinforcement can be carried out between the excavation surface contour line 5 and the groove reinforcement line 8. The groove reinforcement provides a guarantee for the subsequent excavation of the guide groove.

[0027] S3, construction of guide groove and guide frame: construct guide groove 6 along the outer side of excavation surface contour line 5, and fix guide frame 1 in guide groove 6, guide frame 1 includes first section steel frame 11 and second section steel frame 12 arranged inside and outside, multiple inner layer directional tubes 13 are welded between first section steel frame 11 and second section steel frame 12, multiple outer layer directional tubes 14 are welded on the outer arc surface of second section steel frame 12; guide groove and guide frame 1 can provide positioning and guidance for subsequent double-layer small conduit advance support, and also provide accurate embedding space for subsequent temporary shed hole, such as Figure 3 As shown; S4, double-layer small conduit advance support construction: inner layer small conduit 21 and outer layer small conduit 22 are driven into the soil layer through the inner layer directional pipe 13 and the outer layer directional pipe 14, and grouting is performed to reinforce them for advance support; the present invention adopts double-layer small conduit advance support to replace the large pipe shed advance support in the traditional process, which not only makes the construction simpler, but also saves construction time and improves the efficiency of entering the cave.

[0028] S5, temporary shed tunnel construction: align and arrange multiple third steel frames 31 side by side with the first steel frame 11, connect the multiple third steel frames 31 with multiple longitudinal connecting steel bars 32, and set one or two locking anchor pipes 33 at the two feet of each third steel frame 31. After the third steel frame 31 is erected, spray concrete to form a temporary shed tunnel 7; the temporary shed tunnel 7 forms a temporary protection for the tunnel entrance, providing safety for subsequent tunnel construction. Figure 2 As shown; S6, tunnel construction: Use non-blasting or controlled weak blasting excavation methods to enter the tunnel for excavation construction; S7, inverted arch support ring: After 15m into the tunnel, the initial support of the inverted arch is constructed to form a ring.

[0029] At this point, the tunnel entry construction is completed, and subsequent excavation construction can be continued according to the design direction. The present invention achieves "zero" excavation outside the lining contour line, reduces the damage to the original ecological slope vegetation, and at the same time improves the tunnel entry efficiency and shortens the tunnel entry construction time. In addition, the present invention can not only be implemented when the geological conditions at the tunnel entrance are good, the rock mass is stable, and it is not easy to cause safety problems such as landslides, but also under complex geological conditions such as shallow burial, biased pressure, and crushing, through differentiated advanced support technology, such as the arrangement of dense advanced double-layer small conduits, the construction method of the present invention can also be implemented, with less disturbance, zero brushing, protection of the original landform, reduction of soil and water loss, rapid entry, rapid support ring, and ensuring the structural stability of the tunnel entrance section.

[0030] In S2, the diameter of the mortar anchor is φ22 mm, the length is 4 m, the spacing is 1 m×1 m, the diameter of the steel mesh is φ8 mm, the mesh spacing is 20 cm×20 cm, and the sprayed C25 concrete is 10 cm thick.

[0031] In the above S3, the first steel frame 11 and the second steel frame 12 are both made of I22a I-steel, the diameter of the inner directional tube 13 and the outer directional tube 14 are both φ76 mm, and the number of each is 50.

[0032] In the above-mentioned S4, the diameter of the inner layer small tube 21 and the outer layer small tube 22 are both φ42 mm, the length is both 6 m, and the number is both 50.

[0033] In the S5, the third steel frame 31 is made of I20b I-steel, and there are 6 of them. The spacing between adjacent third steel frames 31 is 0.5m. The diameter of the longitudinal connecting steel bars 32 is φ22mm, and the spacing is 1m. The diameter of the locking foot anchor pipe 33 is φ42mm and the length is 5m. The concrete used for spraying is C30 concrete, and the wall thickness after spraying is 30cm.

[0034] like Figure 2 、 Figure 3 、 Figure 4 As shown, the tunnel portal support steel frame structure of the present invention includes a guide frame 1, an advance support structure 2 and a temporary shed steel frame 3. The guide frame 1 includes a first steel frame 11 and a second steel frame 12 arranged inside and outside. A plurality of inner directional tubes 13 are welded between the first steel frame 11 and the second steel frame 12, and a plurality of outer directional tubes 14 are welded on the outer arc surface of the second steel frame 12. The advanced support structure 2 includes an inner layer of small pipes 21 and an outer layer of small pipes 22. The number of the inner layer of small pipes 21 is the same as that of the inner layer of directional pipes 13. The inner layer of small pipes 21 is correspondingly driven through the inner layer of directional pipes 13 and driven into the soil layer. The number of the outer layer of small pipes 22 is the same as that of the outer layer of directional pipes 14. The outer layer of small pipes 22 is correspondingly driven through the outer layer of directional pipes 14 and driven into the soil layer. The temporary shed steel frame 3 includes multiple third-shaped steel frames 31, which are aligned with the first-shaped steel frame 11 and arranged in parallel. The multiple third-shaped steel frames 31 are connected by multiple longitudinal connecting steel bars 32, and each of the two feet of each third-shaped steel frame 31 is provided with one or two locking foot anchor pipes 33.

[0035] The first steel frame 11 and the second steel frame 12 are both I22a I-steel, the diameter of the inner directional tube 13 and the outer directional tube 14 are both φ76 mm, and the number of each is 50.

[0036] The inner layer small tubes 21 and the outer layer small tubes 22 both have a diameter of φ42 mm, a length of 6 m, and a number of 50 tubes.

[0037] The third steel frame 31 is I20b I-steel, with a number of 6 frames. The spacing between adjacent third steel frames 31 is 0.5m. The diameter of the longitudinal connecting steel bars 32 is φ22mm, and the spacing is 1m. The diameter of the locking foot anchor pipe 33 is φ42mm and the length is 5m.

[0038] The present invention adopts a support structure of "guide frame + double-layer small guide tube + temporary shed tunnel", which reduces the excavation wound of the tunnel entrance, shortens the exposure time of the tunnel entrance grooving, controls the tunnel entrance protection project volume, is beneficial to the stability of the back slope, and the tunnel entry construction time can be shortened by about 10 days compared with the traditional tunnel entry construction method, thereby fully improving the tunnel entry efficiency.

[0039] The foregoing description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed herein should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. The high-speed railway tunnel zero excavation construction method is characterized by The following steps are involved: S1, Dangerous rockfall treatment: Before construction, clear the area within the cave entrance and treat the dangerous rockfall on the cave roof (4); S2, reinforcement of the back slope: on the back slope (9), the tunnel excavation surface contour line (5) is measured and laid out, and mortar anchor rods are used to anchor the tunnel within 1-1.5m outside the excavation surface contour line (5), and steel mesh is hung to spray concrete; S3, construction of the guide groove and guide frame: constructing a guide groove (6) along the outer side of the excavation surface contour line (5), and fixing the guide frame (1) in the guide groove (6), wherein the guide frame (1) comprises a first steel frame (11) and a second steel frame (12) arranged inside and outside, a plurality of inner directional tubes (13) being welded between the first steel frame (11) and the second steel frame (12), and a plurality of outer directional tubes (14) being welded on the outer arc surface of the second steel frame (12); S4, double-layer small conduit advance support construction: an inner layer small conduit (21) and an outer layer small conduit (22) are driven into the soil layer through the inner layer directional conduit (13) and the outer layer directional conduit (14), and grouting is performed to reinforce them for advance support; S5, temporary shed hole construction: aligning and arranging multiple third steel frames (31) side by side with the first steel frame (11), connecting the multiple third steel frames (31) with multiple longitudinal connecting steel bars (32), and providing one or two locking foot anchor pipes (33) at the two feet of each third steel frame (31). After the third steel frame (31) is erected, spraying concrete to form a temporary shed hole (7); S6, tunnel construction: Use non-blasting or controlled weak blasting excavation methods to enter the tunnel for excavation construction; S7, inverted arch support ring: After 15m into the tunnel, the initial support of the inverted arch is constructed to form a ring.

2. The high-speed railway tunnel zero-excavation construction method according to claim 1 is characterized in that: In S2, the diameter of the mortar anchor is φ22 mm, the length is 4 m, the spacing is 1 m×1 m, the diameter of the steel mesh is φ8 mm, the mesh spacing is 20 cm×20 cm, and the sprayed C25 concrete is 10 cm thick.

3. The high-speed railway tunnel zero-excavation construction method according to claim 1 or 2, characterized in that: In the S3, the first steel frame (11) and the second steel frame (12) are both made of I22a I-steel, and the diameters of the inner directional tube (13) and the outer directional tube (14) are both φ76 mm, and the number of each is 50.

4. The high-speed railway tunnel zero-excavation construction method according to claim 3 is characterized by: In the S4, the diameter of the inner layer small tube (21) and the outer layer small tube (22) are both φ42 mm, the length is both 6 m, and the number is both 50.

5. The high-speed railway tunnel zero-excavation construction method according to claim 3 is characterized by: In the S5, the third steel frame (31) is made of I20b I-beam, the number is 6, the spacing between adjacent third steel frames (31) is 0.5m, the diameter of the longitudinal connecting steel bar (32) is φ22mm, the spacing is 1m, the diameter of the locking foot anchor pipe (33) is φ42mm, the length is 5m, the concrete used for spraying is C30 concrete, and the wall thickness after spraying is 30cm.

6. The tunnel portal support steel frame structure is characterized by: The invention comprises a guide frame (1), an advance support structure (2) and a temporary shed tunnel steel frame (3), wherein the guide frame (1) comprises a first steel frame (11) and a second steel frame (12) which are arranged inside and outside the guide frame, a plurality of inner directional tubes (13) are welded between the first steel frame (11) and the second steel frame (12), and a plurality of outer directional tubes (14) are welded on the outer arc surface of the second steel frame (12); The advanced support structure (2) includes an inner layer small conduit (21) and an outer layer small conduit (22), the inner layer small conduit (21) and the inner layer directional conduit (13) are of the same number, the inner layer small conduits (21) pass through the inner layer directional conduit (13) and are driven into the soil layer in a one-to-one correspondence, and the outer layer small conduits (22) and the outer layer directional conduit (14) are of the same number, the outer layer small conduits (22) pass through the outer layer directional conduit (14) and are driven into the soil layer in a one-to-one correspondence; The temporary shed steel frame (3) comprises a plurality of third-shaped steel frames (31), the plurality of third-shaped steel frames (31) being aligned with and arranged in parallel with the first-shaped steel frame (11), the plurality of third-shaped steel frames (31) being connected by a plurality of longitudinal connecting steel bars (32), and one or two locking foot anchor pipes (33) being respectively provided at the two feet of each third-shaped steel frame (31).

7. The tunnel portal support steel frame structure according to claim 6, characterized in that: The first steel frame (11) and the second steel frame (12) are both I22a I-beams, and the diameters of the inner directional tubes (13) and the outer directional tubes (14) are both φ76 mm, and the number of each is 50.

8. The tunnel portal support steel frame structure according to claim 6 or 7, characterized in that: The inner layer small conduits (21) and the outer layer small conduits (22) both have a diameter of φ42 mm, a length of 6 m, and a number of 50.

9. The tunnel portal support steel frame structure according to claim 6 or 7, characterized in that: The third steel frame (31) is an I20b I-beam, with a number of 6 frames. The spacing between adjacent third steel frames (31) is 0.5m. The diameter of the longitudinal connecting steel bars (32) is φ22mm, and the spacing is 1m. The diameter of the locking foot anchor pipe (33) is φ42mm and the length is 5m.

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