A large-section railway tunnel shallow-buried bias section uneven surrounding rock on the upper half-section sub-method excavation method

Abstract

The present application relates to the technical field of tunnel construction, in particular to a large-section railway tunnel shallow-buried bias section uneven surrounding rock upper half-section sub-method excavation method, comprising the following steps: step one: increasing the advanced pilot pit at the right side of the upper middle step of the large deformation arch, using artificial excavation with small machinery, using temporary steel frame support for the middle partition wall, and using the right side advanced pilot pit to construct temporary inverted arch; step two: since the left side arch deformation of the tunnel is controllable, still using three-step core soil reservation method construction, excavating and reserving core soil for the left side upper step 5m-7m behind the right side advanced pilot pit, and constructing temporary inverted arch for the middle step after supporting, and connecting with the right side advanced pilot pit temporary inverted arch steel frame; step three: excavating the lower step from left and right sides, and controlling the step length to be 5m-8m; step four: constructing inverted arch to close the ring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a large-section railway tunnel shallow-buried bias section uneven surrounding rock upper half-section sub-method excavation method. BACKGROUND

[0002] The construction of national infrastructure has also ushered in unprecedented development opportunities, and the construction and development of tunnels have always been an important field for improving transportation and infrastructure efficiency. At present, more and more urban tunnels, mountain tunnels, and underwater tunnels are under construction, and tunnel construction is developing towards more complex stratum structures, more difficult tunnel construction, and more stringent quality control. The problems of tunneling under existing buildings, shallow-buried tunnels passing through broken surrounding rock sections, and the like also follow one after another. The bearing capacity of the surrounding rock in the broken and weak surrounding rock section is extremely low, and the tunnel shallow-buried section is prone to arch collapse, ground subsidence and other problems. When the tunnel passes under existing buildings, the stability control of the tunnel itself and the existing buildings is difficult, and the overall design and construction of the tunnel are difficult. Especially when the above engineering problems are manifested in one project, how to optimize the design, how to reduce the engineering risk, how to ensure the stability and coordination of the engineering quality and the existing buildings, and how to control the ground stability and protect the ecology of the construction area have become key problems in tunnel construction.

[0003] After the tunnel excavation enters the dark hole construction, the site excavation reveals that the surrounding rock mass is extremely broken, the rock quality of the working face is soft, the spalling and block falling are serious, the overall stability is poor, the underground water is relatively developed, the tunnel initial support deformation is large, the arch part has large local settlement, the surface above the working face subsides, and transverse and longitudinal cracks appear in many places.

[0004] Therefore, a large-section railway tunnel shallow-buried bias section uneven surrounding rock upper half-section sub-method excavation method is needed to solve the above problems. SUMMARY

[0005] In order to solve the above problems, that is, to solve the problem that the surrounding rock mass is easy to break and has poor stability after tunnel excavation, the present application provides a large-section railway tunnel shallow-buried bias section uneven surrounding rock upper half-section sub-method excavation method.

[0006] A large-section railway tunnel shallow-buried bias section uneven surrounding rock upper half-section sub-method excavation method, comprising the following steps:

[0007] Step one: when the tunnel settlement deformation exceeds the requirements of the relevant technical standards, such as the settlement rate is greater than 10mm / m, or the deformation causes the deformation of the support structure, an advanced pilot tunnel is added at the right side upper middle step position of the tunnel arch, artificial excavation is adopted, a temporary steel frame is used to support the middle partition wall, a temporary inverted arch is constructed at the bottom of the right side advanced pilot tunnel, and a temporary support structure is constructed at the bottom, so that the right side pilot tunnel support structure is closed into a ring;

[0008] Step two: due to the controllable deformation of the left arch of the tunnel, the three-step core soil method is still adopted, the left upper step lags behind the right side by 5-7m and excavates and reserves core soil, and after supporting, the middle step is excavated and the temporary inverted arch is constructed, which is connected with the temporary inverted arch steel frame of the right side advanced guide pit;

[0009] Step three: the lower step is excavated from left and right sides, and the step length is controlled to be 5-8m;

[0010] Step four: the integral tunnel inverted arch is constructed, so that the tunnel support structure is closed into a ring.

[0011] Preferably, a supporting device is arranged inside the tunnel during construction, and the supporting device is arranged in the excavated tunnel part and continuously moves forward with the excavation of the tunnel.

[0012] Preferably, the supporting device comprises two symmetrically arranged frame mechanisms, the frame mechanism comprises an arc-shaped support frame, the lower side of both ends of the support frame is provided with a moving piece, a stabilizing mechanism is arranged between the two frame mechanisms, 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, the processing piece comprises two installation plates fixedly connected to the support frames respectively, a sleeve is fixedly connected to each installation plate, a helical groove is formed in the inner wall of the sleeve, a rotating rod is commonly sleeved in the two sleeves, a first spring is connected between the two ends of the rotating rod and the two sleeves respectively, a catch pin is fixedly connected to the two ends of the rotating rod, the catch pin is inserted into the helical groove, and an abutting plate is arranged on the rotating rod and can abut against the protective layer.

[0014] Preferably, an installation sleeve is fixedly sleeved on the rotating rod, two elastic expansion rods are uniformly fixedly connected to the installation sleeve in the circumferential direction, and the end portion of each elastic expansion rod is fixedly connected with the abutting plate.

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

[0016] Preferably, the moving piece is connected with the support frame through a lifting piece, the lifting piece comprises an oil cylinder fixedly connected to the support plate, a push rod is slidably connected in the oil cylinder, an oil pipe is communicatively arranged on the oil cylinder, the top end of the push rod is fixedly connected with the support frame, and the oil pipe is connected with an oil supply mechanism.

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

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

[0019] The application has the following beneficial effects:

[0020] 1. The construction method combines the advantages of three-step method and side wall pilot tunnel method, and is improved for the case that three-step method cannot be smoothly constructed due to uneven stress distribution of the shallow buried section of the large cross-section tunnel of the high-speed railway and serious deformation of the primary support, the side wall pilot tunnel is used to reduce the span of the chamber excavation and increase the temporary inverted arch for rapid closure to solve the problem of large deformation of surrounding rock, and the three-step method is adjusted for construction under the condition that the deformation of the right side and lower part of the tunnel is controllable, so as to reduce material consumption, equipment and personnel adjustment, and speed up the construction progress.

[0021] 2. The support frame can support the protective layer, so that the protective layer is close to the top wall of the tunnel, blocks the falling debris, avoids the direct falling of the debris in the construction space, and guides the falling of the debris to the two sides of the supporting device to protect the construction space below the protective layer, and the movement of the protective layer is realized by the movement of the support frame.

[0022] 3. The movement of the two frame mechanisms respectively makes the supporting device more stable, and the rotation of the rotating rod is realized by the cooperation of the screw groove and the locking pin when the two frame mechanisms move respectively, so that the abutment plate is rotated, the abutment plate continuously abuts against the protective layer, the protective layer is vibrated, and the accumulation of debris on the protective layer is prevented.

[0023] 4. Through the setting of the elastic expansion rod, the abutting plate can move in a certain circumferential direction when abutting against the protective layer, so as to prevent the abutting plate from exerting excessive abutting force on the protective layer and damaging the protective layer. Through the setting of the lifting piece, the height of the supporting frame can be adjusted according to the height of the tunnel, so as to adjust the height of the protective layer, so that the protective layer is more fitted to the top wall of the tunnel, and the protection effect is better. Through the setting of the stabilizing piece, the positioning nail can be inserted into the ground through the rotation of the rotating sleeve, so as to fix the supporting device, so that the supporting device is more stable when supporting and protecting. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a construction procedure diagram of the present application;

[0025] Figure 2 is a perspective structural schematic view of the supporting device in the present application;

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

[0027] Figure 4 is an isometric side sectional view of A-A in the present application; Figure 3

[0028] Figure 5 is an isometric side sectional view of B-B in the present application; Figure 3

[0029] Figure 6 is a local enlarged view of C in the present application; Figure 4

[0030] Figure 7 is a left view of the present application;

[0031] Figure 8 is an isometric side sectional view of D-D in the present application; Figure 7

[0032] Figure 9 is an isometric side sectional view of E-E in the present application; Figure 7

[0033] Figure 10 is a local enlarged view of C in the present application. Figure 9 In the figure:

[0034]

[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, abutting 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 part; 241, rotating sleeve; 242, positioning nail; 243, handle;

[0037] 3, protective layer. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application.

[0039] The tunnel shallow-buried bias section of the large cross-section railway tunnel is excavated by the uneven surrounding rock upper half cross-section division method, which comprises the following steps:

[0040] Step one: when the tunnel settlement deformation exceeds the requirements of the relevant technical standards, such as the settlement rate is greater than 10mm / m, or the deformation causes the deformation of the supporting structure, an advanced pilot hole is added at the right side of the upper step of the tunnel arch, excavated by artificial cooperation with small machinery, the intermediate partition wall is supported by a temporary steel frame, a temporary inverted arch is constructed at the bottom of the right side advanced pilot hole, and a temporary supporting structure is constructed at the bottom, so that the right side pilot hole supporting structure is closed into a ring;

[0041] Step two: since the deformation of the left side of the tunnel arch is controllable, the three-step core soil method is still used for construction, the left side upper step lags behind the right side advanced pilot hole by 5m-7m excavation and reserves core soil, and after supporting, the middle step is excavated and a temporary inverted arch is constructed, which is connected with the temporary inverted arch steel frame of the right side advanced pilot hole;

[0042] Step three: the lower step is excavated from left and right sides, and the step length is controlled to be 5m-8m;

[0043] Step four: the overall tunnel inverted arch is constructed, so that the tunnel supporting structure is closed into a ring.

[0044] Specifically, the stress distribution of the stratum where the tunnel is located is uneven, with soft upper layer and hard lower layer; the stress distribution of the upper part of the tunnel is uneven, with large deformation on the right side, the right single sidewall pilot tunnel is added to reduce the size of the chamber excavation, the temporary inverted arch is constructed, the radial anchor is used to improve the stability of the surrounding rock; the deformation on the left side is controllable, the three-bench method is used to excavate the upper bench to reserve the core soil to ensure the stability of the working face, after the middle bench is excavated, the temporary inverted arch is connected with the temporary inverted arch of the right side advanced pilot tunnel, and the radial anchor is constructed; the lower bench is excavated on the left and right sides, and finally the inverted arch and low side wall are constructed.

[0045] The construction method combines the advantages of the three-bench method and the sidewall pilot tunnel method, and is improved for the case that the three-bench method cannot be smoothly constructed due to uneven stress distribution of the shallow buried section of the large cross-section tunnel of the high-speed railway, and the deformation of the primary support is serious. The sidewall pilot tunnel is used to reduce the excavation span of the chamber, and the temporary inverted arch is used to quickly close to solve the problem of large deformation of the surrounding rock. In the case that the deformation of the right side and the lower part of the tunnel is controllable, the three-bench method can be conveniently and timely adjusted for construction to reduce material consumption, equipment and personnel adjustment, and speed up the construction progress.

[0046] Further, the construction method comprises determining:

[0047] The on-site excavation reveals that the surrounding rock is crushed rock, the rock mass is extremely broken, the joint is developed, the rock quality of the working face is soft and plastic, the spalling and block falling are serious, and the overall stability is poor. The deformation of the constructed initial support of the tunnel is large, the cumulative maximum settlement is 1091mm, the maximum convergence is 343.3mm, multiple horizontal and vertical cracks appear on the front and rear surfaces of the working face, the surface has already sunk, multiple horizontal cracks have appeared, and some sections have already invaded the limit. After the tunnel is excavated, the upper surrounding rock is relatively soft, the rock quality of the left side 2m below the vault and the right side about 4m is relatively soft and plastic.

[0048] The initial support of the tunnel deforms seriously after construction, the monitoring and measurement results show that the settlement and settlement rate of the right side of the tunnel are significantly higher than those of the vault and the left side, and the convergence deformation is obvious. Therefore, the CD method (CRD method) which is suitable for poor stratum conditions is not suitable for the current situation, because using this method cannot guarantee the smoothness of the tunnel contour, but the right side deforms seriously due to the eccentric pressure on the right side, so the tunnel excavation span is considered to be reduced, and therefore the single sidewall pilot tunnel method is considered to be used for construction. The single sidewall pilot tunnel method has the advantages of reducing the tunnel excavation span, strong stability of the tunnel surrounding rock, and small surface settlement. The settlement and convergence deformation of the left side of the tunnel, the vault, and the speed are within the allowable range, therefore, in order to speed up the construction progress and reduce material consumption, the three-bench method with temporary inverted arch method is used. The right side pilot tunnel is lagged by 5m to 7m, and the core soil is excavated on the left side of the upper bench.

[0049] Further, as shown in Figure 1 , the construction procedure comprises:

[0050] 1. Advanced support

[0051] With the steel frame erected in the last cycle, the tunnel side wall and the pilot side wall φ42 small duct advance support are constructed.

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

[0053] The right side pilot is excavated, and after the excavation is completed, the initial support is promptly constructed, the radial anchor rod is drilled, the 4m long φ22 positioning mortar anchor rod is punched on the left side of the pilot, the I18 type steel is used to construct the temporary vertical support A, and the temporary inverted arch is constructed; the temporary cross brace is erected (one is erected for every two initial support steel frames); the temporary vertical support A is bolted to the tunnel contour initial support and the temporary inverted arch; the steel mesh is laid, the concrete is sprayed, and the temporary inverted arch is closed.

[0054] 3. Excavation of the left side upper step of the reserved core soil

[0055] The left side upper step of the reserved core soil is excavated 5m-7m behind the right side pilot; after completion, the left side upper step initial support is constructed, the initial concrete is sprayed, the steel frame is erected (with the locking foot anchor pipe), the steel reinforcement mesh is laid, the final concrete is sprayed to the designed thickness, and the radial anchor rod is drilled.

[0056] 4. Excavation of the middle step

[0057] The middle step is excavated 3m-5m staggered behind the left side upper step; after completion, the middle step initial support is constructed, the initial concrete is sprayed, the steel frame is erected, the steel reinforcement mesh is laid, the final concrete is sprayed to the designed thickness, the radial anchor rod is drilled, the left side temporary inverted arch is erected (one is erected for every two initial support steel frames), the steel reinforcement mesh is laid, and the concrete is sprayed to close the inverted arch.

[0058] 5. Excavation of the lower step

[0059] After 10m-15m behind the middle step, the lower step is excavated and supported left and right staggered, and after the excavation is completed, the side wall initial support is constructed, i.e. the initial concrete is sprayed, the steel frame is erected, the steel reinforcement mesh is laid, the final concrete is sprayed to the designed thickness, and the radial anchor rod is drilled.

[0060] 6. Excavation of the lower inverted arch area

[0061] After 5m behind the lower step, the inverted arch excavation support is constructed. The inverted arch is excavated no more than 3m at a time, and after the inverted arch is closed in a ring for 6m, the inverted arch and the filling are promptly constructed.

[0062] Further, the 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 construction to the surrounding rock, and the working face is a soil and stone stratum, the artificial and mechanical excavation method is adopted to reduce the disturbance of the blasting to the surrounding rock.

[0064] The right side single sidewall pilot tunnel is excavated by a small excavator with a bucket capacity of 0.6 m3, and the left side bench method is excavated by an excavator with a bucket capacity of 1.2 m3.

[0065] Further, the monitoring measurement includes:

[0066] During the tunnel construction process, the three-dimensional laser scanner and the total station are used to conduct the surrounding rock monitoring measurement according to the relevant requirements of the specification, including the observation of the surrounding rock and support state, the ground settlement, the arch top subsidence, the peripheral convergence and other items.

[0067] The stability of the inlet section slope is good during the monitoring period of the project, and no instability signs are observed. The tunnel settlement deformation and convergence area in the tunnel tend to be stable.

[0068] Further, the temporary structure removal includes:

[0069] The temporary structure removal includes the removal of the sidewall support, the temporary inverted arch, the sprayed concrete and the steel mesh and the like. During the construction process, after the first ring inverted arch filling layer is completed, according to the monitoring measurement data, the standard for the arch top settlement to reach stability is that the settlement rate is not more than 0.1 mm / d, and the standard for the horizontal convergence to reach stability is that the convergence rate is not more than 0.2 mm / d, and the temporary structure can be removed.

[0070] According to the tunnel construction organization and in combination with the actual situation on site, the construction is carried out in the following order: mechanical breaking of the concrete between the steel frames to be removed → erection of scaffolding and safety net → manual cleaning of the remaining sprayed concrete → removal of temporary support → treatment of surface attachments → supplementary spraying of concrete to level the removal position pit.

[0071] The tunnel surrounding rock and the initial support are caused by the stress redistribution due to the removal of the temporary support, in order to avoid the occurrence of instability caused by stress mutation, a 5m test section is selected for trial removal before removal. According to the method of removing one every three, the tunnel deformation is stabilized, and then each section is removed.

[0072] When the temporary steel support is removed, the cable and pulley combination is used to fix the two ends of the temporary inverted arch steel support on the next section of steel frame, the electrical welding or the removal of the connecting bolts are used to cut off the connection between the temporary inverted arch steel support and the initial support and the sidewall steel support, the cable constraint is removed and the temporary inverted arch steel support is slowly placed on the ground, if necessary, the loader hopper can be used to cooperate with the temporary inverted arch steel support to lift and place, so as to be simple and convenient to operate. The sidewall pilot tunnel temporary vertical support is removed in the same way.

[0073] The temporary support shotcrete is removed by mechanical removal combined with manual air pick cleaning, and the steel mesh is cut by electric welding. The shotcrete is removed from top to bottom, and the process should ensure the effective connection of the connecting steel to the arch frame to form a whole, so as to prevent the sudden instability of the side wall support during the removal process. After the removal is completed, the concrete and steel waste are cleaned in time.

[0074] The removal length is less than 5m (5-7 steel frames), and the monitoring and measurement is strengthened during the removal process. If there is an abnormality, the monitoring and measurement data is locally encrypted and processed dynamically.

[0075] Specifically, the use of this construction method increases the right side wall guide pit temporary vertical support, advanced small guide pipe, positioning mortar anchor rod and other materials, and increases two excavators, which increases the cost by about 1 million yuan. The original construction method construction paragraph is 50m, and the arch replacement is 30m, which leads to an increase of 1.4 million yuan in cost. If the original construction method is still used for construction, the 210m paragraph is expected to increase the cost of arch replacement by about 5.88 million yuan.

[0076] After using this construction method, the monthly progress is 45m, and the monthly progress of the original construction method is 20m, with a progress benefit of 12.25 million yuan. Therefore, this construction method brings about 17 million yuan in economic benefits. After the original construction method construction enters the shallow buried paragraph, the tunnel primary support deforms severely, and during the construction method change exploration period, nearly 300 days of work are caused. During the construction process of this construction method, there is no serious deformation, the tunnel deformation value is stable and meets the requirements, and the regional ground surface settlement tends to be stable and meets the requirements. This construction method can safely and efficiently ensure the construction progress and quality of the tunnel.

[0077] After the tunnel construction enters the shallow buried paragraph, the tunnel primary support deforms severely, and there are falling pieces and the like, which cannot continue construction. During the construction method change period, in order to ensure safe construction, a large pipe shed construction is added for testing, but the effect is not obvious, which leads to no construction progress in this paragraph for nearly 300 days. The paragraph using this construction method is 210m in total, and the total construction period is 193 days, which ensures the construction period, and the tunnel deformation and convergence are stable during the construction period, and there is no risk of large deformation, etc. The successful implementation of this construction method has solved the problem of shallow buried and bias pressure construction of large cross-section tunnel of high-speed railway, and has received unanimous praise from the construction unit, supervision unit and design unit, and has won very good social benefits for our unit.

[0078] Using this construction method is expected to reduce the arch replacement by 126m, and reduce the waste of arch frame, concrete and other resources. During the construction process and after the construction is completed, the tunnel monitoring and measurement and ground surface settlement observation show that the tunnel deformation is stable, the ground surface does not appear large deformation, and the construction and external environment are stable, which ensures the safety of the construction workers, construction management personnel and nearby living personnel.

[0079] Further, a supporting device is arranged inside the tunnel during construction, which is arranged in the excavated tunnel part and moves forward with the tunnel excavation.

[0080] As shown in Figure 2 , 3 , the supporting device comprises two frame mechanisms 1 arranged symmetrically, each frame mechanism 1 comprises an arc-shaped support frame 11, the lower side of the two ends of the support frame 11 is provided with a moving part 12, 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, which is made of flexible material.

[0081] Specifically, in use, the supporting 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 falling stones directly fall on the protective layer 3, and then the stones slide along the arc surface of the protective layer 3 to the two sides of the supporting device, protecting the space below the protective layer 3; with the excavation of the tunnel, 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 supporting device moves with the excavation of the tunnel.

[0082] Through the arrangement of 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, and the falling stones are blocked, avoiding the stones falling directly into the construction space, and through the guiding effect of the protective layer 3, the stones fall to the two sides of the supporting device, protecting the construction space below the protective layer 3, and through the arrangement of the moving part 12, the support frame 11 can move with the tunnel excavation, thereby driving the protective layer 3 to move, realizing protection while excavating.

[0083] As shown in Figure 3 , 4 , a processing part 13 is arranged between the two support frames 11, the processing part 13 comprises two mounting plates 131 fixedly connected to the support frames 11 respectively, a sleeve 132 is fixedly connected to each mounting plate 131, a spiral groove is formed in the inner wall of the sleeve 132, a rotating rod 133 is commonly sleeved in the two sleeves 132, first springs 134 are connected between the two ends of the rotating rod 133 and the two sleeves 132 respectively, a locking pin is fixedly connected to the two ends of the rotating rod 133, the locking pin is inserted into the spiral groove, an abutting plate 135 is arranged on the rotating rod 133, and the abutting plate 135 can abut against the protective layer 3.

[0084] Specifically, in use, the moving part 12 in the edge frame mechanism 1 away from the tunneling direction is moved, so that the moving part 12 drives the edge frame mechanism 1 to move towards the tunneling direction, the moving part 12 drives the support frame 11 to move, the support frame 11 drives the mounting plate 131 to move, the mounting plate 131 drives the sleeve 132 to move, the sleeve 132 slides on the rotating rod 133, due to the arrangement of the spiral groove, the rotating rod 133 rotates, and at the same time, the first spring 134 is compressed, the rotating rod 133 drives the abutting plate 135 to rotate, so that the abutting plate 135 constantly 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 part 12, the two edge frame mechanisms 1 are close to each other, so that the protective layer 3 is folded towards the middle; then stop the movement of the moving part 12, move the moving part 12 in the edge frame mechanism 1 close to the tunneling direction, and the moving part 12 drives the edge frame mechanism 1 to move, and the edge frame mechanism 1 drives the protective layer 3 to unfold.

[0085] Through the arrangement of the moving part 12, the two edge frame mechanisms 1 can be moved respectively when the device is in use, so that the support device moves more stably, and through the arrangement of the processing part 13, when the two edge frame mechanisms 1 move respectively, the rotating rod 133 can be rotated through the cooperation of the spiral groove and the locking pin, so as to drive the abutting plate 135 to rotate, so that the abutting plate 135 constantly abuts against the protective layer 3, so that the protective layer 3 vibrates, preventing the accumulation of gravel on the protective layer 3.

[0086] As shown in Figure 6 , the mounting sleeve 136 is fixedly sleeved on the rotating rod 133, two elastic expansion rods 137 are uniformly and fixedly connected in the circumferential direction on the mounting sleeve 136, and the end of each elastic expansion rod 137 is fixedly connected with the abutting plate 135.

[0087] Specifically, in use, when the rotating rod 133 rotates, the rotating rod 133 drives the mounting sleeve 136 to rotate, the mounting sleeve 137 drives the elastic expansion rod 137 to rotate, the elastic expansion rod 137 drives the abutting plate 135 to rotate, and the abutting plate 135 constantly abuts against the protective layer 3.

[0088] Through the arrangement of the elastic expansion rod 137, the abutting plate 135 can move circumferentially when it abuts against the protective layer 3, preventing the abutting plate 135 from exerting excessive abutting force on the protective layer 3 and damaging the protective layer 3.

[0089] As shown in Figure 5 , the moving part 12 comprises a support plate 121, the support frame 11 is arranged on the support plate 121, two rolling shafts 122 are rotatably connected to the bottom surface of the support plate 121, a rolling wheel 123 is fixedly sleeved on the rolling shaft 122, and one of the rolling shafts 122 is fixedly connected with the output end of the moving motor 124.

[0090] Specifically, in use, when the moving piece 12 needs to move, the moving motor 124 is started, the output end of the moving motor 124 drives the roller shaft 122 to rotate, and the roller shaft 122 drives the roller 123 to move on the ground.

[0091] Through the arrangement of the moving piece 12, the support plate 121 can be driven to move by the rotation of the moving motor 124, and the support frame 11 can be driven to move by the support plate 121, so as to realize the movement of the support device.

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

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

[0094] Through the arrangement of the lifting piece 14, the height of the support frame 11 can be adjusted according to the height of the tunnel, so as to adjust the height of the protective layer 3, so that the protective layer 3 is more fitted to the top wall of the tunnel, and the protection effect is better.

[0095] Further, the oil supply mechanism is prior art, which will not be described here.

[0096] As shown in Figure 5 , two stable mechanisms 2 are symmetrically arranged between the two frame mechanisms 1, the stable mechanism 2 includes a rod sleeve 21, two extension rods 22 are symmetrically and slidingly connected in the rod sleeve 21, the ends of the two extension rods 22 are respectively rotationally connected with two oil cylinders 141 in the two frame mechanisms 1, 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, in use, when the moving piece 12 drives the lifting piece 14 to move, the lifting piece 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] Through the arrangement of the stable mechanism 2, when the two frame mechanisms 1 move, the two frame mechanisms 1 are kept on the same axis, so that the support device moves more stably.

[0099] As shown in Figure 7 、 8 The rod sleeve 21 is sleeved with a stabilizing piece 24, the stabilizing piece 24 comprises a rotating sleeve 241 fixedly sleeved on the rod sleeve 21, one end of the rotating sleeve 241 is fixedly connected with three positioning nails 242, and the other end of the rotating sleeve 241 is fixedly connected with a handle 243.

[0100] Specifically, 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, the rotating sleeve 241 drives the positioning nails 242 to rotate, and the positioning nails 242 are inserted into the ground.

[0101] Through the arrangement of the stabilizing piece 24, the positioning nails 242 can be inserted into the ground through the rotation of the rotating sleeve 241, so that the supporting device is fixed, and the supporting device is more stable when supporting and protecting.

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

[0103] In addition, it should be further pointed out that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0104] The term "includes" or any other similar term is intended to cover non-exclusive inclusion, so that the process, article or equipment / device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes the elements inherent to the process, article or equipment / device.

[0105] The technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical schemes after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A method for excavating a large-section railway tunnel shallow-buried bias section on a non-uniform surrounding rock upper half-section by division method, characterized in that, Includes the following steps: Step 1: When the tunnel settlement deformation exceeds the relevant technical standard requirements, and the settlement rate is greater than 10mm / m, or the deformation causes the support structure to deform, an advance pilot pit is added at the upper middle step on the right side of the tunnel arch. The excavation is carried out manually in conjunction with small machinery. The middle partition wall is supported by a temporary steel frame. A temporary inverted arch is constructed at the bottom of the right advance pilot pit, and a temporary support structure is constructed at the bottom, so that the support structure of the right pilot pit is closed into a ring. Step 2: Since the deformation of the left arch of the tunnel is controllable, the three-stage reserved core soil method is still adopted for construction. The upper stage on the left is excavated 5m to 7m behind the pilot tunnel on the right and the core soil is reserved. After support, the middle stage of the excavation is used to construct a temporary invert arch, which is connected to the temporary invert arch steel frame of the pilot tunnel on the right. Step 3: Excavate the lower steps on both the left and right sides, with the step length controlled between 5m and 8m; Step 4: Construct the integral tunnel invert arch to close the tunnel support structure into a ring; During construction, support devices are installed inside the tunnel. These support devices are placed in the excavated sections of the tunnel and are continuously moved and advanced as the tunnel is excavated. The support device includes two symmetrically arranged frame mechanisms (1), each frame mechanism (1) includes an arc-shaped support frame (11), and movable parts (12) are provided on the lower sides of both ends of the support frame (11). A stabilizing mechanism (2) is provided between the two frame mechanisms (1), and an arc-shaped protective layer (3) is provided between the two support frames (11). The protective layer (3) is made of flexible material. A processing component (13) is provided between the two support frames (11). The processing component (13) includes two mounting plates (131) that are 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 fitted in the two sleeves (132). A first spring (134) is connected between the two ends of the rotating rod (133) and the two sleeves (132). A locking pin is fixedly connected to both ends of the rotating rod (133). The locking pin is inserted into the spiral groove. An abutment plate (135) is provided on the rotating rod (133). The abutment plate (135) can abut against the protective layer (3).

2. The method according to claim 1, characterized in that, An installation sleeve (136) is fixedly sleeved on the rotating rod (133), and two elastic telescopic rods (137) are evenly fixedly connected to the installation sleeve (136) along the circumferential direction. The end of each elastic telescopic rod (137) is fixedly connected to the abutment plate (135).

3. The method for excavating the upper half of the uneven surrounding rock in the shallow buried section of a large-section railway tunnel according to claim 2, characterized in that, The moving part (12) includes a support plate (121), and the support frame (11) is disposed on the support plate (121). Two rollers (122) are rotatably connected to the bottom surface of the support plate (121). Rollers (123) are fixedly sleeved on the rollers (122), and one of the rollers (122) is fixedly connected to the output end of the moving motor (124).

4. The method for excavating the upper half of the uneven surrounding rock in the shallow buried section of a large-section railway tunnel according to claim 3, characterized in that, The movable component (12) is connected to the support frame (11) via a lifting component (14). The lifting component (14) includes a hydraulic cylinder (141) fixedly connected to the support plate (121). A push rod (142) is slidably connected in the hydraulic cylinder (141). An oil pipe (143) is connected to the hydraulic cylinder (141). The top end of the push rod (142) is fixedly connected to the support frame (11). An oil supply mechanism is connected to the oil pipe (143).

5. The method for excavating the upper half of the uneven surrounding rock in the shallow buried section of a large-section railway tunnel according to claim 4, characterized in that, Two stabilizing mechanisms (2) are symmetrically arranged between the two frame mechanisms (1). The stabilizing mechanism (2) includes a sleeve (21). Two extension rods (22) are symmetrically slidably connected in the sleeve (21). The ends of the two extension rods (22) are rotatably connected to two oil cylinders (141) in the two frame mechanisms (1). A second spring (23) is connected between the two extension rods (22). The second spring (23) is located in the sleeve (21).

6. The method for excavating the upper half of the uneven surrounding rock in the shallow buried section of a large-section railway tunnel according to claim 5, characterized in that, The rod sleeve (21) is fitted with a stabilizing element (24), the stabilizing element (24) includes a rotating sleeve (241) fixedly fitted on the rod sleeve (21), one end of the rotating sleeve (241) is fixedly connected with three positioning pins (242), and the other end of the rotating sleeve (241) is fixedly connected with a handle (243).

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