Method for excavating upper half section of non-uniform surrounding rock in shallow-buried and bias-pressure section of large-section railway tunnel by adopting division method

Abstract

The invention relates to the technical field of tunnel construction, in particular to a large-section railway tunnel shallow-buried bias-pressure section non-uniform surrounding rock upper half section division method excavation method which comprises the following steps: step 1, adding an advanced pilot tunnel at the upper middle step part of the right side of an arch part with larger deformation, and excavating by adopting manual work in cooperation with a small machine, a middle partition wall is supported by a temporary steel frame, and a temporary inverted arch is constructed in a right-side advanced pilot tunnel; secondly, due to the fact that deformation of the left arch portion of the tunnel is controllable, a three-step core soil reserving method is still adopted for construction, an upper step on the left side is excavated 5-7 m behind the right advance pilot tunnel, core soil is reserved, a middle step is excavated after supporting, a temporary inverted arch is constructed, and the middle step is connected with a temporary inverted arch steel frame of the right advance pilot tunnel; 3, excavating a lower step on the left side and the right side, and controlling the length of the step to be 5m-8m; and fourthly, an inverted arch is constructed to be closed into a ring.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a method for excavating the upper half section of uneven surrounding rock in a shallow buried biased section of a large-section railway tunnel using a segmented method. Background Art

[0002] The construction of national infrastructure has also ushered in unprecedented development opportunities. The construction and development of tunnels have always been an important area for improving the efficiency of transportation and infrastructure. At present, more and more urban tunnels, mountain tunnels, and undersea tunnels are being built, and tunnel construction is also developing in the direction of more complex stratum structures, more difficult tunnel construction, and stricter quality control. The problems of tunnels passing under existing buildings and shallow buried tunnels passing through broken surrounding rock areas have also come one after another. The bearing capacity of tunnels in broken and weak surrounding rock areas is extremely low. The shallow buried section of the tunnel is prone to problems such as vault collapse and surface subsidence. When the tunnel passes under existing buildings, it is difficult to control the stability of the tunnel itself and the existing buildings, and the overall design and construction of the tunnel are difficult. Especially when the above engineering problems are reflected in one project at the same time, how to optimize the design, how to reduce engineering risks, how to ensure the stability and coordination of engineering quality and existing buildings, how to control the surface stability and protect the ecology of the construction area have become key issues in tunnel construction.

[0003] After the tunnel excavation entered the blind cave construction, on-site excavation revealed that the surrounding rock mass was extremely broken, the rock on the heading was soft, there was serious spalling and falling, the overall stability was poor, the groundwater was relatively developed, the initial support of the tunnel that had been constructed had large deformation, the local settlement of the arch was large, the surface above the heading was sinking, and many horizontal and vertical cracks appeared.

[0004] Therefore, a method for excavating the upper half section of uneven surrounding rock in the shallow buried biased section of a large-section railway tunnel is needed to solve the above problems. Summary of the invention

[0005] In order to solve the above problem, that is, to solve the problem that the surrounding rock mass is easily broken and has poor stability after tunnel excavation, the present invention provides a method for excavating the upper half section of uneven surrounding rock in a shallow buried biased section of a large-section railway tunnel by partial excavation.

[0006] A method for excavating the upper half section of uneven surrounding rock in a shallow buried biased section of a large-section railway tunnel by a partial excavation method comprises the following steps:

[0007] Step 1: When the tunnel settlement deformation exceeds the requirements of relevant technical standards, such as when the settlement rate is greater than 10 mm / m, or its deformation causes deformation of the support structure, an advance pilot pit is added to the upper middle step on the right side of the tunnel arch, and excavation is carried out by manual labor and small machinery. The middle partition wall is supported by a temporary steel frame, and a temporary invert is constructed at the bottom of the right advance pilot pit, and a temporary support structure is constructed at the bottom, so that the right pilot pit support structure is closed into a ring;

[0008] Step 2: As the deformation of the left arch of the tunnel is controllable, the three-step reserved core soil method is still used for construction. The left upper step is excavated 5m to 7m behind the right leading pilot tunnel and the core soil is reserved. After support, the middle step is excavated to construct a temporary inverted arch, which is connected to the temporary inverted arch steel frame of the right leading pilot tunnel.

[0009] Step 3: Excavate the lower steps on the left and right sides, and control the step length to 5m to 8m;

[0010] Step 4: Construct the overall tunnel invert to close the tunnel support structure into a ring.

[0011] Preferably, a support device is arranged inside the tunnel during the construction process. The support device is arranged in the excavated tunnel portion and is continuously advanced and moved as the tunnel is excavated.

[0012] Preferably, the supporting device includes two symmetrically arranged frame mechanisms, the frame mechanisms include an arc-shaped support frame, movable parts are arranged on the lower sides of both ends of the support frame, a stabilizing mechanism is arranged between the two frame mechanisms, and an arc-shaped protective layer is arranged between the two support frames, and the protective layer is made of flexible material.

[0013] Preferably, a processing piece is arranged between the two support frames, and the processing piece includes two mounting plates respectively fixedly connected to the support frames, a sleeve is fixedly connected to each mounting plate, a spiral groove is provided on the inner wall of the sleeve, a rotating rod is commonly sleeved in the two sleeves, both ends of the rotating rod are respectively connected to the two sleeves with a first spring, both ends of the rotating rod are fixedly connected with a bayonet pin, the bayonet pin is inserted into the spiral groove, an abutment plate is arranged on the rotating rod, and the abutment plate can abut against the protective layer.

[0014] Preferably, a mounting sleeve is provided on the fixed sleeve on the rotating rod, and two elastic telescopic rods are evenly and fixedly connected to the mounting sleeve along the circumferential direction, and the end of each elastic telescopic rod is fixedly connected to the abutment plate.

[0015] Preferably, the movable member comprises a support plate, the support frame is arranged on the support plate, the bottom surface of the support plate is rotatably connected to two rollers, rollers are fixedly sleeved on the rollers, and one of the rollers is fixedly connected to the output end of the movable motor.

[0016] Preferably, the movable part is connected to the support frame through a lifting part, and the lifting part includes a cylinder fixedly connected to the support plate, a push rod is slidably connected in the cylinder, an oil pipe is connected to the cylinder, the top end of the push rod is fixedly connected to the support frame, and the oil pipe is connected to an oil supply mechanism.

[0017] Preferably, two stabilizing mechanisms are symmetrically arranged between the two frame mechanisms, and the stabilizing mechanism includes a rod sleeve, in which two extension rods are symmetrically slidably connected, and the ends of the two extension rods are respectively rotatably connected to the two oil cylinders in the two frame mechanisms, and a second spring is connected between the two extension rods, and the second spring is located in the rod sleeve.

[0018] Preferably, a stabilizing member is sleeved on the rod sleeve, and the stabilizing member comprises a rotating sleeve fixedly sleeved on the rod sleeve, one end of the rotating sleeve is fixedly connected to three positioning pins, and the other end of the rotating sleeve is fixedly connected to a handle.

[0019] The beneficial effects of the present invention are:

[0020] 1. This construction method combines the advantages of the three-step method and the sidewall pilot method. It is improved to address the situation where the three-step method cannot be smoothly constructed due to uneven stress distribution in the shallow buried section of a large-section high-speed railway tunnel, and the initial support deformation is serious. The sidewall pilot is used to reduce the excavation span of the cavern, and a temporary invert is added for rapid closure to solve the problem of large deformation of the surrounding rock. When the deformation on the right side and the lower part of the tunnel is controllable, it can be conveniently and timely adjusted to the three-step method for construction to reduce material consumption, equipment and personnel adjustments, and speed up the construction progress.

[0021] 2. Through the setting of the support frame, the protective layer can be supported so that the protective layer is close to the top wall of the tunnel, blocking the falling gravel and preventing the gravel from falling directly into the construction space. Through the guiding effect of the protective layer, the gravel falls to both sides of the support device to protect the construction space under the protective layer. In addition, through the setting of the moving parts, the support frame can move with the excavation of the tunnel, thereby driving the protective layer to move and realizing protection while excavating.

[0022] 3. Through the setting of the moving parts, when the device is in use, the two frame mechanisms can be moved separately, so that the support device is more stable when moving, and through the setting of the processing parts, when the two frame mechanisms are moved separately, the spiral groove and the bayonet can be used to cooperate with each other to make the rotating rod rotate, thereby driving the abutment plate to rotate, so that the abutment plate is constantly in abutment with the protective layer, causing the protective layer to vibrate, thereby preventing gravel from accumulating on the protective layer.

[0023] 4. By setting the elastic telescopic rod, the abutment plate can move in a certain circumferential direction when abutting against the protective layer, so as to prevent the abutment plate from applying too much abutment force to the protective layer, thereby damaging the protective layer. By setting the lifting member, the height of the support frame can be adjusted according to the height of the tunnel, thereby adjusting the height of the protective layer, so that the protective layer fits the top wall of the tunnel better, and the protective effect is better. By setting the stabilizing member, the positioning nail can be inserted into the ground by rotating the rotating sleeve, so that the support device is fixed, making the support device more stable when performing support protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a construction process diagram of the present invention;

[0025] Figure 2 It is a schematic diagram of the three-dimensional structure of the support device in the present invention;

[0026] Figure 3 It is a front view of the present invention;

[0027] Figure 4 For the present invention Figure 3 Isometric section view at AA;

[0028] Figure 5 For the present invention Figure 3 Isometric section view at the middle BB;

[0029] Figure 6 For the present invention Figure 4 A partial enlarged view of point C in the middle;

[0030] Figure 7 It is a left side view of the present invention;

[0031] Figure 8 For the present invention Figure 7 Isometric section view at mid DD;

[0032] Fig. 9 For the present invention Figure 7 Isometric section view at EE;

[0033] Fig.10 For the present invention Fig. 9 A partial enlarged view of point C in the middle.

[0034] In the figure:

[0035] 1. frame mechanism; 11. support frame; 12. moving part; 121. support plate; 122. roller; 123. roller; 124. moving motor; 13. processing part; 131. mounting plate; 132. sleeve; 133. rotating rod; 134. first spring; 135. abutment plate; 136. mounting sleeve; 137. elastic telescopic rod; 14. lifting part; 141. oil cylinder; 142. push rod; 143. oil pipe;

[0036] 2. Stabilizing mechanism; 21. Rod sleeve; 22. Extension rod; 23. Second spring; 24. Stabilizing member; 241. Rotating sleeve; 242. Positioning pin; 243. Handle;

[0037] 3. Protective layer. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0039] The embodiment of the present invention discloses a method for excavating the upper half section of uneven surrounding rock in a shallow buried biased section of a large-section railway tunnel by a partial excavation method, comprising the following steps:

[0040] Step 1: When the tunnel settlement deformation exceeds the requirements of relevant technical standards, such as when the settlement rate is greater than 10 mm / m, or its deformation causes deformation of the support structure, an advance pilot pit is added to the upper middle step on the right side of the tunnel arch, and excavation is carried out by manual labor and small machinery. The middle partition wall is supported by a temporary steel frame, and a temporary invert is constructed at the bottom of the right advance pilot pit, and a temporary support structure is constructed at the bottom, so that the right pilot pit support structure is closed into a ring;

[0041] Step 2: As the deformation of the left arch of the tunnel is controllable, the three-step reserved core soil method is still used for construction. The left upper step is excavated 5m to 7m behind the right leading pilot tunnel and the core soil is reserved. After support, the middle step is excavated to construct a temporary inverted arch, which is connected to the temporary inverted arch steel frame of the right leading pilot tunnel.

[0042] Step 3: Excavate the lower steps on the left and right sides, and control the step length to 5m to 8m;

[0043] Step 4: Construct the overall tunnel invert to close the tunnel support structure into a ring.

[0044] Specifically, the stress distribution in the stratum where the tunnel is located is uneven, with the upper part being soft and the lower part being hard; the stress distribution in the upper part of the tunnel is uneven, with a large deformation on the right side. A single side wall pilot pit is added on the right side to reduce the size of the cavern excavation, a temporary invert is constructed, radial anchors are installed, and the stability of the surrounding rock is improved; the deformation on the left side is controllable, and the three-step method is used to excavate the upper step to reserve core soil to ensure the stability of the heading face. After the middle step is excavated, a temporary invert is constructed to connect it with the temporary invert of the right advance pilot pit, and radial anchors are installed; the lower step is excavated on the left and right sides, and finally an invert and a low side wall are constructed.

[0045] This construction method combines the advantages of the three-step method and the sidewall pilot method. It is improved to solve the problem of serious deformation of the initial support due to uneven stress distribution in the shallow buried section of a large-section high-speed railway tunnel, which makes the three-step method unable to be smoothly constructed. The sidewall pilot is used to reduce the excavation span of the cavern, and a temporary invert is added for rapid closure to solve the problem of large deformation of the surrounding rock. When the deformation of the right side and the lower part of the tunnel is controllable, it can be conveniently and timely adjusted to the three-step method for construction to reduce material consumption, equipment and personnel adjustments, and speed up the construction progress.

[0046] Further, including the construction method determination:

[0047] On-site excavation revealed that the surrounding rock is crushed rock, the rock mass is extremely broken, the joints are well developed, the rock quality of the face is soft and plastic, the block peeling is serious, and the overall stability is poor. The initial support deformation of the constructed tunnel is large, with a cumulative maximum settlement of 1091mm and a maximum convergence of 343.3mm. There are many horizontal and vertical cracks on the surface in front and behind the face. It has already sunk, and many horizontal cracks have occurred. Some sections have been intruded. After the tunnel was excavated, the upper surrounding rock was relatively soft, and the rock quality was relatively soft and plastic in the range of 2m on the left and about 4m on the right below the face arch.

[0048] After the tunnel was constructed, the initial support was severely deformed. The monitoring and measurement results showed that the settlement and settlement rate on the right side of the tunnel were significantly higher than those on the vault and the left side, and the convergence deformation was obvious. Therefore, the CD method (CRD method) suitable for poor strata was not suitable for the situation at that time, because this method could not ensure the smoothness of the tunnel contour. However, due to the bias pressure on the right side of the tunnel, the right side was severely deformed. Considering reducing the tunnel excavation span, the single-side wall pilot method was considered for construction. The single-side wall pilot method has the advantages of reducing the tunnel excavation span, strong tunnel surrounding rock stability and small surface settlement. The settlement and convergence deformation and speed of the left side and vault of the tunnel were within the allowable range. Therefore, in order to speed up the construction progress and reduce material consumption, the three-step method plus temporary invert method was adopted. The right pilot pit was delayed by 5m to 7m, and the core soil was reserved to excavate the upper step on the left side.

[0049] Further, such as Figure 1 As shown, the construction process includes:

[0050] 1. Advance support

[0051] The steel frame erected in the previous cycle is used to construct advance support for the tunnel side walls and pilot pit side walls using φ42 small guide pipes.

[0052] 2. Excavation and support of the right pilot pit

[0053] Excavate the right pilot pit. After the excavation is completed, carry out initial support in time, drill radial anchors, drive 4mφ22 positioning mortar anchors on the left side of the pilot pit, use I18 steel to construct temporary vertical support A, and construct temporary invert; erect temporary cross braces (one for every two initial support steels); connect the temporary vertical support A with the tunnel contour initial support and temporary invert with bolts; lay steel mesh, spray concrete, and close the temporary invert.

[0054] 3. Reserve the core soil to dig the upper steps on the left side

[0055] The left upper step is excavated 5m to 7m behind the right pilot pit by using the reserved core soil method; after completion, the initial support of the left upper step is carried out, initial concrete is sprayed, a steel frame is erected (with locking anchor pipes), steel mesh is laid, concrete is sprayed again to the designed thickness, and radial anchors are drilled.

[0056] 4. Excavation of the middle step

[0057] The middle step is excavated 3m to 5m behind the upper step on the left side. After completion, initial support for the middle step is carried out, initial concrete spraying is carried out, steel frames are erected, steel mesh is laid, concrete is sprayed again to the designed thickness, radial anchors are drilled, a temporary invert is erected on the left side (one for every two initial support steel frames), steel mesh is laid, and concrete is sprayed to close the invert.

[0058] 5. Dig down the steps

[0059] After lagging the middle step by 10m to 15m, the excavation and support of the lower step are staggered on the left and right. After the excavation is completed, the initial support of the side wall is carried out, that is, the initial concrete spraying, the erection of steel frame, the laying of steel mesh, the re-spraying of concrete to the designed thickness, and the drilling of radial anchors.

[0060] 6. Excavation of the lower invert area

[0061] After 5m of the lower step, the arch excavation support is carried out. The arch excavation should not exceed 3m at a time. After the arch is closed into a ring of 6m, the arch and filling are carried out in time.

[0062] Furthermore, mechanical excavation includes:

[0063] Due to the serious deformation of the tunnel and the large settlement of the ground surface, in order to reduce the disturbance of the surrounding rock caused by construction, and the fact that the heading face is a soil-rock stratum, manual and mechanical excavation is adopted to reduce the disturbance of the surrounding rock caused by blasting.

[0064] The single-wall pilot tunnel on the right was excavated using a small excavator with a bucket capacity of 0.6m3, while the step method on the left was excavated using an excavator with a bucket capacity of 1.2m3.

[0065] Furthermore, monitoring measurements include:

[0066] During the tunnel construction process, 3D laser scanners and total stations are used to monitor and measure the surrounding rock in accordance with relevant specifications, including observation of surrounding rock and support status, surface settlement, vault subsidence, peripheral convergence and other projects.

[0067] The slope of the entrance section has good stability during the monitoring period of this project, and no signs of instability are found. The settlement deformation and convergence area of ​​the tunnel are stable.

[0068] Furthermore, the temporary structure demolition includes:

[0069] The temporary structure demolition includes the demolition of side wall supports, temporary inverts, shotcrete and steel mesh, etc. During the construction process, after the filling layer of the first ring of inverts is completed, according to the monitoring and measurement data, the standard for the arch top settlement to reach stability is that the settlement rate does not exceed 0.1mm / d, and the standard for the horizontal convergence to reach stability is that the convergence rate does not exceed 0.2mm / d, then the temporary structure can be demolished.

[0070] According to the organization of tunnel construction and the actual situation on site, construction is carried out in the following order: mechanically break up the concrete between the steel frames that need to be removed → erect scaffolding and safety nets → manually clean up the remaining shotcrete → remove temporary supports → handle surface attachments → additional shotcrete spraying to level the pit at the removal location.

[0071] The removal of temporary support caused stress redistribution in the tunnel surrounding rock and initial support. To avoid instability caused by sudden stress change, a 5m test section was selected for trial dismantling before dismantling. The trial dismantling was carried out according to the method of dismantling 1 every 3 sections. After confirming that the tunnel deformation was stable, the sections were dismantled one by one.

[0072] When dismantling the temporary steel support, use a combination of cables and pulleys to fix both ends of the temporary inverted arch steel support to the next steel frame, and use electric welding or loosening the connecting bolts to cut off the connection between the temporary inverted arch steel support and the initial support and side wall steel support. Remove the cable constraints and slowly place the temporary inverted arch steel support on the ground. If necessary, use a loader bucket to cooperate with the temporary inverted arch steel support to lift and place it for easy operation. The temporary vertical support of the side wall guide pit is dismantled in the same way.

[0073] Temporary support shotcrete removal is carried out by mechanical removal combined with manual pneumatic pick cleaning, and the steel mesh is cut by electric welding. The shotcrete is removed from the top to the bottom of each arch frame. During the process, the effective connection of the connecting steel bars to the arch frame should be ensured as much as possible, so that the temporary support forms a whole, and the sudden instability of the side wall support during the removal process is prevented. After the removal is completed, the concrete, steel bars and other waste materials are cleaned up in time.

[0074] The length of demolition at one time is less than 5m (5-7 steel frames). During the demolition process, monitoring and measurement are strengthened. If any abnormality occurs, the monitoring and measurement data is locally encrypted and dynamically set.

[0075] Specifically, the use of this construction method to construct the section requires the addition of temporary vertical supports for the right wall guide pit, small advance guide tubes, positioning mortar anchors and other materials, as well as the addition of two excavators, with a total additional cost of about 1 million yuan. The original construction method constructed a 50m section, and the cost of replacing the arch for 30m increased by 1.4 million yuan. If the original construction method is still used for construction, the estimated cost of replacing the arch for 210m in this section is about 5.88 million yuan.

[0076] After adopting this construction method, the monthly progress is 45m, while the monthly progress of the original construction method is 20m, and the progress benefit is 12.25 million yuan. Therefore, this construction method brings economic benefits of about 17 million yuan. After the original construction method entered the shallow buried section, the initial support of the tunnel was severely deformed, and during the exploration of the change of construction method, nearly 300 days of idle work were caused. In addition, there is no serious deformation during the construction process of this construction method, the tunnel deformation value is stable and meets the requirements, and the surface settlement is also stable and meets the requirements. This construction method can safely and efficiently ensure the progress and quality of tunnel construction.

[0077] After the tunnel construction entered the shallow buried section, the initial support of the tunnel was severely deformed, with blocks falling off, and construction could not continue. During the change of construction methods, in order to ensure safe construction, a large pipe shed construction was added for testing, but the effect was not obvious, resulting in the inability to construct. As a result, there was no construction progress in this section for nearly 300 days. This method was used for a total of 210m of sections with a total construction period of 193 days, which ensured the construction period. During the construction period, the tunnel deformed and converged stably, and there was no risk of large deformation. The difficult problem of shallow buried bias pressure construction of large-section tunnels on high-speed railways was successfully solved. The successful implementation of this method has been unanimously praised by the construction unit, supervision unit, and design unit, and has won very good social benefits for our unit.

[0078] The construction method is expected to reduce the arch replacement by 126m and reduce the waste of arch frames, concrete and other resources. In addition, during and after the construction, tunnel monitoring and measurement and surface settlement observation show that the tunnel deformation is stable and the surface has not undergone significant deformation, ensuring the stability of the construction and external environment, and ensuring the safety of construction workers, construction management personnel and nearby residents.

[0079] Furthermore, during the construction process, a support device is arranged inside the tunnel. The support device is arranged in the excavated tunnel portion and is continuously advanced and moved as the tunnel is excavated.

[0080] like Figure 2 , 3 As shown in 4, the supporting device includes two symmetrically arranged frame mechanisms 1, the frame mechanism 1 includes an arc-shaped support frame 11, and moving parts 12 are arranged on the lower sides of both ends of the support frame 11. A stabilizing mechanism 2 is arranged between the two frame mechanisms 1, and an arc-shaped protective layer 3 is arranged between the two support frames 11, and the protective layer 3 is made of flexible material.

[0081] Specifically, when in use, the support device is located in the tunnel, and the two frame mechanisms 1 support the protective layer 3 so that the protective layer 3 is close to the top surface of the tunnel, so that the gravel falls directly on the protective layer 3 when it falls, and then the gravel slides along the curved surface of the protective layer 3 to the two sides of the support device to protect the space under the protective layer 3; as the tunnel is excavated, the moving part 12 is started, the moving part 12 drives the support frame 11 to step, and the support frame 11 drives the protective layer 3 to move, so that the support device moves as the tunnel is excavated.

[0082] By setting the support frame 11, the protective layer 3 can be supported so that the protective layer 3 is close to the top wall of the tunnel, blocking the falling gravel and preventing the gravel from falling directly into the construction space. Through the guiding effect of the protective layer 3, the gravel falls to both sides of the support device to protect the construction space under the protective layer 3. Moreover, by setting the moving part 12, the support frame 11 can move with the excavation of the tunnel, thereby driving the protective layer 3 to move and realizing protection while excavating.

[0083] like Figure 3 , 4 As shown in Figure 6, a processing part 13 is arranged between the two support frames 11, and the processing part 13 includes two mounting plates 131 respectively fixedly connected to the support frames 11, and a sleeve 132 is fixedly connected to each of the mounting plates 131. A spiral groove is provided on the inner wall of the sleeve 132, and a rotating rod 133 is commonly sleeved in the two sleeves 132. The two ends of the rotating rod 133 are respectively connected to the two sleeves 132 with a first spring 134, and the two ends of the rotating rod 133 are fixedly connected with a bayonet, and the bayonet is inserted into the spiral groove. An abutment plate 135 is provided on the rotating rod 133, and the abutment plate 135 can abut against the protective layer 3.

[0084] Specifically, when in use, the moving member 12 in the frame mechanism 1 is moved away from the tunnel excavation direction, so that the moving member 12 drives the frame mechanism 1 to move in the tunnel excavation direction, and the moving member 12 drives the support frame 11 to move, and the support frame 11 drives the mounting plate 131 to move, and the mounting plate 131 drives the sleeve 132 to move, and the sleeve 132 slides on the rotating rod 133. Due to the setting of the spiral groove, the rotating rod 133 rotates, and at the same time, the first spring 134 is compressed, and the rotating rod 133 drives the abutment plate 135 to rotate, so that the abutment plate 135 continuously abuts against the protective layer 3, so that the protective layer 3 vibrates, and at the same time, due to the movement of the moving member 12, the two frame mechanisms 1 are close to each other, so that the protective layer 3 is folded toward the middle; then the movement of the moving member 12 is stopped, and the moving member 12 in the frame mechanism 1 close to the excavation direction is moved, and the moving member 12 drives the frame mechanism 1 to move, and the frame mechanism 1 drives the protective layer 3 to unfold.

[0085] By setting the moving part 12, when the device is in use, the two frame mechanisms 1 can be moved separately, so that the support device is more stable when moving, and by setting the processing part 13, when the two frame mechanisms 1 are moved separately, the spiral groove and the bayonet can be used to cooperate with each other to make the rotating rod 133 rotate, thereby driving the abutment plate 135 to rotate, so that the abutment plate 135 is constantly in abutment with the protective layer 3, so that the protective layer 3 vibrates, thereby preventing gravel from accumulating on the protective layer 3.

[0086] like Figure 6 As shown, a mounting sleeve 136 is fixedly mounted on the rotating rod 133 , and two elastic telescopic rods 137 are evenly and fixedly connected to the mounting sleeve 136 along the circumferential direction, and the end of each elastic telescopic rod 137 is fixedly connected to the abutment plate 135 .

[0087] Specifically, during use, when the rotating rod 133 rotates, the rotating rod 133 drives the installation sleeve 136 to rotate, the installation sleeve 137 drives the elastic telescopic rod 137 to rotate, the elastic telescopic rod 137 drives the abutment plate 135 to rotate, and the abutment plate 135 continuously abuts against the protective layer 3.

[0088] By setting the elastic telescopic rod 137, the abutting plate 135 can move in a certain circumferential direction when abutting against the protective layer 3, so as to prevent the abutting plate 135 from applying too large abutting force to the protective layer 3, thereby damaging the protective layer 3.

[0089] like Figure 5 As shown, the movable member 12 includes a support plate 121, the support frame 11 is arranged on the support plate 121, the bottom surface of the support plate 121 is rotatably connected to two rollers 122, and a roller 123 is fixedly sleeved on the roller 122, one of the rollers 122 is fixedly connected to the output end of the moving motor 124.

[0090] Specifically, when the movable member 12 is required to move during use, the movable motor 124 is started, the output end of the movable motor 124 drives the roller 122 to rotate, the roller 122 drives the roller 123 to rotate, and the roller 123 moves on the ground.

[0091] By setting the moving member 12 , the support plate 121 can be driven to move by the rotation of the moving motor 124 , and the support plate 121 drives the support frame 11 to move, thereby realizing the movement of the supporting device.

[0092] like Figure 3 , 5 As shown in 10, the movable member 12 is connected to the support frame 11 through a lifting member 14, and the lifting member 14 includes a cylinder 141 fixedly connected to the support plate 121, a push rod 142 is slidably connected in the cylinder 141, and an oil pipe 143 is connected to the cylinder 141, the top end of the push rod 142 is fixedly connected to the support frame 11, and the oil pipe 143 is connected to an oil supply mechanism.

[0093] Specifically, when in use, the oil supply mechanism is started according to the height of the tunnel, the oil supply mechanism inputs hydraulic oil into the oil pipe 143, the hydraulic oil enters the oil cylinder 141, so that the push rod 142 rises, the push rod 142 drives the support frame 11 to rise, and the support frame 11 drives the protective layer 3 to rise.

[0094] By setting the lifting member 14, the height of the support frame 11 can be adjusted according to the height of the tunnel, thereby adjusting the height of the protective layer 3, so that the protective layer 3 fits the top wall of the tunnel better and has a better protective effect.

[0095] Furthermore, the oil supply mechanism is prior art and will not be described in detail.

[0096] like Figure 5 As shown, two stabilizing mechanisms 2 are symmetrically arranged between the two frame mechanisms 1, and the stabilizing mechanism 2 includes a rod sleeve 21, and two extension rods 22 are symmetrically slidably connected in the rod sleeve 21, and the ends of the two extension rods 22 are respectively rotatably connected to the two oil cylinders 141 in the two frame mechanisms 1, and a second spring 23 is connected between the two extension rods 22, and the second spring 23 is located in the rod sleeve 21.

[0097] Specifically, when in use, when the moving member 12 drives the lifting member 14 to move, the lifting member 14 drives the extension rod 22 to move in the rod sleeve 21 , and at the same time, the extension rod 22 compresses the second spring 23 .

[0098] By setting the stabilizing mechanism 2, when the two frame mechanisms 1 move, the two frame mechanisms 1 are kept on the same axis, so that the supporting device is more stable when moving.

[0099] like Figure 7 , 8 As shown, a stabilizing member 24 is sleeved on the rod sleeve 21, and the stabilizing member 24 includes a rotating sleeve 241 fixedly sleeved on the rod sleeve 21, one end of the rotating sleeve 241 is fixedly connected to three positioning pins 242, and the other end of the rotating sleeve 241 is fixedly connected to a handle 243.

[0100] Specifically, when in use, when the supporting device is moved to a suitable position, the handle 243 is moved, so that the handle 243 drives the rotating sleeve 241 to rotate, and the rotating sleeve 241 drives the positioning nail 242 to rotate, so that the positioning nail 242 is inserted into the ground.

[0101] By providing the stabilizing member 24 , the positioning nail 242 can be inserted into the ground by rotating the rotating sleeve 241 , thereby fixing the supporting device and making the supporting device more stable when performing supporting protection.

[0102] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0103] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0104] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0105] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for excavating the upper half section of uneven surrounding rock in a shallow buried biased section of a large-section railway tunnel, characterized in that: The following steps are involved: Step 1: When the tunnel settlement deformation exceeds the requirements of relevant technical standards, such as when the settlement rate is greater than 10mm / m, or its deformation causes deformation of the support structure, an advance pilot pit is added at the upper middle step on the right side of the tunnel arch, and excavation is carried out by manual labor and small machinery. The middle partition wall is supported by a temporary steel frame, and a temporary invert is constructed at the bottom of the right advance pilot pit, and a temporary support structure is constructed at the bottom, so that the right pilot pit support structure is closed into a ring; Step 2: As the deformation of the left arch of the tunnel is controllable, the three-step reserved core soil method is still used for construction. The left upper step is excavated 5m to 7m behind the right leading pilot tunnel and the core soil is reserved. After support, the middle step is excavated to construct a temporary inverted arch, which is connected to the temporary inverted arch steel frame of the right leading pilot tunnel. Step 3: Excavate the lower steps on the left and right sides, and control the step length to 5m to 8m; Step 4: Construct the overall tunnel invert to close the tunnel support structure into a ring.

2. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 1 is characterized in that: During the construction process, a support device is installed inside the tunnel. The support device is set in the excavated tunnel section and is continuously advanced and moved as the tunnel is excavated.

3. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 2 is characterized in that: The support device comprises two symmetrically arranged frame mechanisms (1), the frame mechanism (1) comprising an arc-shaped support frame (11), movable members (12) being arranged at the lower sides of both ends of the support frame (11), a stabilizing mechanism (2) being arranged between the two frame mechanisms (1), and an arc-shaped protective layer (3) being arranged between the two support frames (11), the protective layer (3) being made of a flexible material.

4. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 3 is characterized in that: A processing member (13) is arranged between the two support frames (11), and the processing member (13) comprises two mounting plates (131) respectively fixedly connected to the support frames (11), a sleeve (132) is fixedly connected to each mounting plate (131), a spiral groove is provided on the inner wall of the sleeve (132), a rotating rod (133) is commonly sleeved in the two sleeves (132), the two ends of the rotating rod (133) are respectively connected to the two sleeves (132) with a first spring (134), the two ends of the rotating rod (133) are fixedly connected with a bayonet, the bayonet is inserted into the spiral groove, and an abutment plate (135) is arranged on the rotating rod (133), and the abutment plate (135) can abut against the protective layer (3).

5. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 4 is characterized in that: A mounting sleeve (136) is fixedly mounted on the rotating rod (133), and two elastic telescopic rods (137) are evenly and fixedly connected to the mounting sleeve (136) along a circumferential direction, and the end of each elastic telescopic rod (137) is fixedly connected to the abutment plate (135).

6. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 5 is characterized in that: The moving member (12) comprises a support plate (121), the support frame (11) is arranged on the support plate (121), the bottom surface of the support plate (121) is rotatably connected to two rollers (122), a roller (123) is fixedly sleeved on the rollers (122), and one of the rollers (122) is fixedly connected to the output end of a moving motor (124).

7. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 6 is characterized in that: The movable member (12) is connected to the support frame (11) via a lifting member (14); the lifting member (14) comprises an oil cylinder (141) fixedly connected to the support plate (121); a push rod (142) is slidably connected in the oil cylinder (141); an oil pipe (143) is provided in communication with the oil cylinder (141); the top end of the push rod (142) is fixedly connected to the support frame (11); and the oil pipe (143) is connected to an oil supply mechanism.

8. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 7 is characterized in that: Two stabilizing mechanisms (2) are symmetrically arranged between the two frame mechanisms (1), and the stabilizing mechanism (2) comprises a rod sleeve (21), and two extension rods (22) are symmetrically slidably connected in the rod sleeve (21), and the ends of the two extension rods (22) are respectively rotatably connected to the two oil cylinders (141) in the two frame mechanisms (1), and a second spring (23) is connected between the two extension rods (22), and the second spring (23) is located in the rod sleeve (21).

9. The method for excavating the upper half section of uneven surrounding rock in a shallow-buried biased section of a large-section railway tunnel according to claim 8, characterized in that: The rod sleeve (21) is sleeved with a stabilizing member (24), and the stabilizing member (24) comprises a rotating sleeve (241) fixedly sleeved on the rod sleeve (21), one end of the rotating sleeve (241) is fixedly connected to three positioning pins (242), and the other end of the rotating sleeve (241) is fixedly connected to a handle (243).

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