An assembled corrugated steel-filling layer composite tunnel support system and construction method thereof

Abstract

The present invention belongs to the field of tunnel construction, and specifically relates to an assembled corrugated steel-filling layer composite tunnel support system and a construction method thereof. The technical scheme is as follows: it includes a corrugated steel-filling layer composite plate, a steel tube-concrete composite beam, an advance small conduit and an H-shaped steel supporting structure; the steel tube-concrete composite beam is a connecting member arranged between the upper corrugated steel-filling layer composite plate and the lower corrugated steel-filling layer composite plate; the corrugated steel-filling layer composite plate includes an upper step part and a lower step part, and the upper step part and the lower step part are combined together by an H-shaped steel supporting structure, and the end of the H-shaped steel supporting structure is fixedly connected to the steel tube-concrete composite beam by high-strength bolts; a plurality of advance small conduits penetrate the steel tube-concrete composite beam and are inserted in front of the tunnel excavation face, and the tail end of the advance small conduit is arranged on the steel tube-concrete composite beam. The present invention has the advantages of low engineering cost, light weight, strong bearing capacity, and simple repair, and has better applicability in the field of tunnel construction.

Description

Technical Field

[0001] The invention belongs to the field of tunnel construction, and in particular relates to an assembled corrugated steel-filling layer composite tunnel support system and a construction method thereof. Background Art

[0002] At present, open-cut and dark-cut methods are commonly used in tunnel construction. In dark-cut tunnel construction, shotcrete support is often used as the initial support system of the tunnel. The entire support system consists of concrete layers, steel grids, anchor rods and other components to jointly bear the surrounding rock pressure. The traditional shotcrete support has a long construction period and cannot achieve rapid closure of the surrounding rock. At the same time, the cost is high and it is difficult to repair it later. The above shortcomings make the dark-cut tunnel construction method have certain limitations in application.

[0003] Based on the traditional sprayed anchor support system, many scholars have proposed a support system with corrugated steel plates as the main supporting structure. Corrugated steel plates have the advantages of high strength and good bending resistance. Corrugated steel plates and other components are prefabricated components. They are assembled on site after being prefabricated in the factory. The construction is simple and the construction period is effectively reduced. At the same time, the factory prefabrication ensures the accuracy of the components and satisfies the construction quality. With corrugated steel plates as the support structure, there is no need to spray concrete during the construction process, which reduces the use of concrete and reduces the construction cost.

[0004] At present, there are still many deficiencies in the corrugated steel plate tunnel support system:

[0005] 1) There is little introduction to advance support in tunnel support in the prior art. There is no description of how the advance small guide tube is combined with other components in the entire corrugated steel plate support system, and there is no supporting construction method, which makes it difficult to actually apply it during the construction process.

[0006] 2) In the existing technology, the reinforcement of corrugated steel plates and ring beams usually adopts steel supports, angle steels and other components, which makes the construction process complicated and increases the construction period and construction cost.

[0007] 3) In the prior art, the corrugated steel plates are directly connected longitudinally by bolts. Regardless of whether the overlap method or the flange is used, it is difficult to fix the bolts at the back of the corrugated steel plates.

[0008] The existing technology is as follows:

[0009] 1) Corrugated steel plate tunnel initial support structure and tunnel (authorization announcement number CN 212337366 U)

[0010] Disadvantages: The annular beam and corrugated steel plate use different reinforcement measures to enhance the supporting capacity of the upper steps during construction. These measures make the construction process complicated, increase the construction period, and require a large number of steel supports, angle steels and ribs, which increases the construction cost. At the same time, there is no supporting advance support system in this patent, which makes the application of this patent have certain limitations.

[0011] 2) Corrugated steel plate assembly for support and tunnel support method (authorization announcement number CN 107435547 B)

[0012] Disadvantages: In order to ensure the firmness of the connection, the adjacent corrugated steel plate units are connected by bolts in an overlapping manner in this patent, and no other components are used as connecting components between the longitudinal corrugated steel plates. This method is difficult to implement during the construction process. There is surrounding rock behind the corrugated steel plate. After the overlapping between the adjacent corrugated steel plate units is completed, it is difficult to fix the bolts behind the corrugated steel plate.

[0013] 3) A steel-FRP composite corrugated steel plate tunnel support method (application publication number CN 107780949 A)

[0014] Disadvantages: The patent does not provide a detailed introduction to the advance support of the tunnel. It simply explains that the surrounding rock is reinforced by grouting in advance through a small advance grouting conduit before excavation, but there is no relevant construction method. At the same time, the corrugated steel plates in the patent are connected longitudinally by flanges and two rows of bolts. This method is difficult to implement during construction. There is surrounding rock behind the corrugated steel plates, which makes it difficult to install the upper row of bolts at the connection of the corrugated steel plates. The corrugated steel plates on the upper steps and the corrugated steel plates on the side walls of the patent are fixed by locking anchor rods at the arch feet. This method requires reserving more holes in the corrugated steel plates, which destroys the integrity of the corrugated steel plates. Summary of the invention

[0015] The present invention discloses an assembled corrugated steel-filling layer composite tunnel support system and a construction method thereof. The components are produced in a standardized manner in a factory and assembled on site, which saves construction time, can achieve rapid closure of surrounding rocks, and complete the initial support of the tunnel. The system has the advantages of low engineering cost, light weight, strong bearing capacity, and easy repair.

[0016] The technical solution of the present invention is as follows:

[0017] An assembled corrugated steel-filling layer composite tunnel support system comprises a corrugated steel-filling layer composite plate, a steel tube-concrete composite beam, an advance small conduit and an H-shaped steel supporting structure, wherein the steel tube-concrete composite beam is a connecting member arranged between an upper corrugated steel-filling layer composite plate and a lower corrugated steel-filling layer composite plate; the corrugated steel-filling layer composite plate comprises an upper step portion and a lower step portion, which are combined together through an H-shaped steel supporting structure, and the end of the H-shaped steel supporting structure is fixedly connected to the steel tube-concrete composite beam through high-strength bolts; a plurality of advance small conduits penetrate the steel tube-concrete composite beam and are inserted in front of the tunnel excavation face, the tail end of the advance small conduit is arranged on the steel tube-concrete composite beam, and the angle between the advance small conduit and the corrugated steel-filling layer composite plate is 8-12 degrees.

[0018] Furthermore, the fabricated corrugated steel-filling layer composite tunnel support system, wherein the corrugated steel-filling layer composite plate comprises a corrugated steel plate and a concrete filling layer; the corrugated steel plate has a reserved grouting hole, grouting is performed on the back of the corrugated steel plate through a pair of grouting holes to form a concrete filling layer between the back of the corrugated steel plate and the interface between the surrounding rock; the corrugated steel plate and the concrete filling layer form a combined structure that is jointly stressed to improve the supporting capacity.

[0019] Furthermore, in the assembled corrugated steel-filling layer composite tunnel support system, the corrugated steel plate has a welded flange at the edge; a bolt hole is reserved on the flange; and the multiple corrugated steel plates are connected and staggered by high-strength bolts. Furthermore, in the assembled corrugated steel-filling layer composite tunnel support system, the corrugated steel plates are respectively the first corrugated steel plate, the second corrugated steel plate, the third corrugated steel plate and the fourth corrugated steel plate; the upper step portion of the corrugated steel-filling layer composite plate is formed by combining and connecting the first corrugated steel plate, the second corrugated steel plate and the third corrugated steel plate, and the two ends of the third corrugated steel plate are respectively connected to the first corrugated steel plate and the second corrugated steel plate; the lower step portion of the corrugated steel-filling layer composite plate is composed of the fourth corrugated steel plate.

[0020] Furthermore, in the assembled corrugated steel-filling layer composite tunnel support system, the first corrugated steel plate and the second corrugated steel plate are both connected between the steel tube-concrete composite beam and the third corrugated steel plate, and the nature of the two is transition corrugated steel plates; the waveforms of the first corrugated steel plate and the second corrugated steel plate are transition waves between large waveforms and small waveforms, the size of the large waveform is consistent with that of the third corrugated steel plate, and the size of the small waveform is smaller than that of the third corrugated steel plate; the first corrugated steel plate and the second corrugated steel plate play a transition role between the steel tube-concrete composite beam and the third corrugated steel plate, effectively reducing the angle of the advance small duct and avoiding collision between the corrugated steel plate and the advance small duct during construction.

[0021] Furthermore, in the fabricated corrugated steel-filling layer composite tunnel support system, shear nails are welded at the troughs on the back side of the corrugated steel plate component to improve the anti-slip performance between the corrugated steel plate and the concrete filling layer.

[0022] Furthermore, the assembled corrugated steel-filling layer composite tunnel support system, wherein the steel tube-concrete composite beam comprises an annular steel tube and concrete in the tube, the concrete in the tube is poured inside the steel tube; the steel tube is assembled from steel tube components, the steel tube components are provided with a socket structure, two bolt holes, a reserved hole and two grouting holes, the steel tube components are assembled together through the socket structure; the reserved hole is used to support the advance small guide tube, and the two grouting holes are used to grout into the interior of the steel tube; the socket structures and the steel tube and the corrugated steel plate are connected by high-strength bolts.

[0023] Furthermore, in the fabricated corrugated steel-filling layer composite tunnel support system, the H-steel supporting structure includes H-steel and locking anchor rods; the web of the H-steel is provided with stiffening ribs and locking anchor rod holes; a hole is drilled into the surrounding rock through the locking anchor rod holes, and the locking anchor rod is inserted into the surrounding rock after passing through the locking anchor rod holes, so as to fix the H-steel on the surrounding rock; end connecting plates are welded at both ends of the H-steel, and the end connecting plates are provided with bolt holes three; bolt holes four are provided on the upper and lower flange portions of the H-steel; high-strength bolts are used to connect the H-steels, between the H-steel and the corrugated steel plate, and between the H-steel and the steel tube-concrete composite beam.

[0024] The construction method of the above-mentioned assembled corrugated steel-filling layer composite tunnel support system comprises the following steps:

[0025] 1) Carry out advanced support operations:

[0026] The steel pipe components are first spliced ​​at the tunnel entrance. The steel pipe components are connected by the socket structure and the splicing construction is carried out from one side to the other side in sequence. After the steel pipe components are assembled, holes are drilled into the surrounding rock through the reserved holes, and then the advance small guide tube is driven into the surrounding rock. Then, the advance small guide tube is grouted to realize the advance support operation during the construction process.

[0027] 2) Carry out the upper step support construction:

[0028] First, the upper step part of the tunnel is excavated, and the core soil part is retained; after the excavation is completed, the H-shaped steel is installed, and the H-shaped steel is installed at the elevation position of the arch foot, and a hole is drilled into the surrounding rock through the locking foot anchor hole, and then the locking foot anchor is driven into the surrounding rock to fix the H-shaped steel, and then the steel pipe component and the H-shaped steel are connected by high-strength bolts;

[0029] Then, the corrugated steel plates are assembled. The first corrugated steel plate is assembled from both sides to the arch top. The first corrugated steel plate is connected to the H-shaped steel on both sides of the arch foot, and the first corrugated steel plate is connected to the steel pipe member through high-strength bolts; after the first corrugated steel plate is assembled, the third corrugated steel plate is assembled. After the third corrugated steel plate is assembled, the second corrugated steel plate is assembled, and the second corrugated steel plate is connected to the steel pipe member of the next ring through high-strength bolts; the third corrugated steel plate and the second corrugated steel plate are connected to the H-shaped steel on both sides of the arch foot; the first corrugated steel plate, the third corrugated steel plate, and the second corrugated steel plate are connected by high-strength bolts; the corrugated steel plates are assembled by staggered assembly;

[0030] 3) Carry out tunnel lower step construction:

[0031] Excavate the core soil of the upper step and the lower step of the tunnel; after the excavation is completed, assemble the fourth corrugated steel plate in a symmetrical manner from both sides to the bottom. The fourth corrugated steel plate on both sides of the lower step is connected to the H-shaped steel by high-strength bolts, so that the corrugated steel plates of the upper and lower steps form a closed ring-shaped whole. After assembling one ring, carry out the tunnel support construction of the next ring along the longitudinal construction;

[0032] 4) Carry out grouting construction:

[0033] After the corrugated steel plates are assembled, concrete slurry is poured into the steel pipe components through grouting holes 2 to form concrete inside the pipe; then, concrete slurry is poured behind the corrugated steel plates through grouting holes 1, and the grouting sequence is from both sides to the middle along the longitudinal construction direction to form a concrete filling layer; the corrugated steel plates form a combined structure with the concrete filling layer through the shear nails, and after the concrete is initially set, a complete assembled corrugated steel-filling layer composite tunnel support system is formed.

[0034] Furthermore, in the construction method of the assembled corrugated steel-filling layer composite tunnel support system, the steel pipes are assembled in a half ring or a full ring.

[0035] The beneficial effects of the present invention are:

[0036] 1) The present invention proposes a concept of initial tunnel support based on a corrugated steel plate-filling layer composite plate structure and a steel tube-concrete composite beam structure. By filling concrete behind the corrugated steel plate components and inside the steel tube components, a composite structure is formed to solve the problems of low bearing capacity of steel structures and poor deformation resistance of concrete structures, thereby improving the bearing capacity of the support structure.

[0037] 2) The present invention proposes a steel tube-concrete composite beam component, which is used as a connecting component between the upper ring and the lower ring of corrugated steel plates, thereby solving the inconvenience of bolting the longitudinal corrugated steel plates. The steel tube in the component is provided with bolt holes for connection with the corrugated steel plates on both sides, a socket structure for assembling the steel tube into a ring, a reserved hole for supporting the small advance guide tube, and a grouting hole for grouting inside the steel tube. Grouting inside the steel tube can not only form a composite structure and improve the bearing capacity of the component, but also improve the connection strength at the connection node.

[0038] 3) The present invention proposes a combined support system of corrugated steel plates, steel pipes and advance small conduits, and fully introduces the construction method of advance support in the corrugated steel plate tunnel support system, which fills the gap in the current relevant technical field and solves the problem that when corrugated steel plates are used alone for support, the advance small conduits cut through the corrugated steel plates, causing the strength of the corrugated steel plates to decrease. At the same time, in order to meet the angle requirements of the advance small conduits, three different corrugated steel plates are used in the upper step construction part, making the connection between the corrugated steel plates, square steel pipes and advance small conduits more reasonable and the construction process more convenient.

[0039] 4) The present invention is designed to use a ribbed H-shaped steel member as a connecting piece between the upper step and the lower step members. Stiffening ribs are welded on the belly of the member to improve the compressive resistance, and locking foot anchor holes are reserved on the belly plate for driving the locking foot anchors. Connecting plates are provided at the ends to achieve self-splicing, which effectively solves the problems of arch foot shrinkage and upper step support. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the overall structural diagram of the assembled corrugated steel-filling layer composite tunnel support system;

[0041] Figure 2 This is the structural diagram of the first corrugated steel plate component;

[0042] Figure 3 This is the structural diagram of the third corrugated steel plate component;

[0043] Figure 4 It is the structural diagram of steel pipe components;

[0044] Figure 5 This is the connection effect diagram of the advance support structure;

[0045] Figure 6 It is the longitudinal section diagram of the advanced support structure connection;

[0046] Figure 7 This is the H-shaped steel supporting structure diagram.

[0047] In the figure: 1-corrugated steel-filling layer composite plate, 2-steel tube-concrete composite beam, 3-H-steel supporting structure, 5-shear nails, 6-high-strength bolts, 11-first corrugated steel plate, 12-second corrugated steel plate, 13-third corrugated steel plate, 14-fourth corrugated steel plate, 15-concrete filling layer, 16-flange, 161-bolt hole one, 17-grouting hole one, 21-steel tube component, 22-advance small guide tube, 23-concrete in the tube, 31-H-steel, 32-locking foot anchor rod, 211-reserved hole, 212-grouting hole two, 213-socket structure, 214-bolt hole two, 311-locking foot anchor rod hole, 312-stiffening rib, 313-end connecting plate, 314-bolt hole three, 315-bolt hole four. DETAILED DESCRIPTION

[0048] like Figure 1-7 As shown, an assembled corrugated steel-filling layer composite tunnel support system includes a corrugated steel-filling layer composite plate 1, a steel tube-concrete composite beam 2, an advance small guide tube 22 and an H-shaped steel supporting structure 3; the steel tube-concrete composite beam 2 is a connecting member arranged between the upper corrugated steel-filling layer composite plate 1 and the lower corrugated steel-filling layer composite plate 1; the corrugated steel-filling layer composite plate 1 includes an upper step part and a lower step part, and the upper step part and the lower step part are combined together by an H-shaped steel supporting structure 3, and the end of the H-shaped steel supporting structure 3 is fixedly connected to the steel tube-concrete composite beam 2 by a high-strength bolt 6; a plurality of advance small guide tubes 22 penetrate the steel tube-concrete composite beam 2 and are inserted in front of the tunnel excavation face, and the tail end of the advance small guide tube 22 is arranged on the steel tube-concrete composite beam 2, and the angle between the advance small guide tube 22 and the corrugated steel-filling layer composite plate 1 is 10°.

[0049] The corrugated steel-filling layer composite plate 1 includes a corrugated steel plate and a concrete filling layer 15; the corrugated steel plate has a reserved grouting hole 17, and grouting is performed on the back of the corrugated steel plate through the grouting hole 17 to form a concrete filling layer 15 between the back of the corrugated steel plate and the interface with the surrounding rock; the corrugated steel plate and the concrete filling layer 15 form a combined structure to bear force together to improve the supporting capacity.

[0050] The corrugated steel plate has a welded flange 16 on its edge; a bolt hole 161 is reserved on the flange 16; the multiple corrugated steel plates are connected and assembled with staggered joints by high-strength bolts 6. The corrugated steel plates are respectively the first corrugated steel plate 11, the second corrugated steel plate 12, the third corrugated steel plate 13 and the fourth corrugated steel plate 14; the upper step portion of the corrugated steel-filling layer composite plate 1 is formed by combining and connecting the first corrugated steel plate 11, the second corrugated steel plate 12 and the third corrugated steel plate 13, and the two ends of the third corrugated steel plate 13 are respectively connected to the first corrugated steel plate 11 and the second corrugated steel plate 12; the lower step portion of the corrugated steel-filling layer composite plate 1 is formed by the fourth corrugated steel plate 14.

[0051] The first corrugated steel plate 11 and the second corrugated steel plate 12 are both connected between the steel tube-concrete composite beam 2 and the third corrugated steel plate 13, and the properties of the two are transition corrugated steel plates; the waveforms of the first corrugated steel plate 11 and the second corrugated steel plate 12 are transition waves between large waveforms and small waveforms, the size of the large waveform is consistent with the third corrugated steel plate 13, and the size of the small waveform is smaller than the waveform size of the third corrugated steel plate 13; the first corrugated steel plate 11 and the second corrugated steel plate 12 play a transition role between the steel tube-concrete composite beam 2 and the third corrugated steel plate 13, effectively reducing the angle of the leading small duct 22, and avoiding collision between the corrugated steel plate and the leading small duct 22 during construction.

[0052] The size of the first corrugated steel plate 11 is wave pitch × wave height × wall thickness = 230mm × 64mm × 5mm; the size of the second corrugated steel plate 12 is wave pitch × wave height × wall thickness = 230mm × 64mm × 5mm; the half period of the edge connection of the first corrugated steel plate 11 and the second corrugated steel plate 12 adopts the same size as the third corrugated steel plate 13; the size of the third corrugated steel plate 13 is wave pitch × wave height × wall thickness = 400mm × 150mm × 5mm; the size of the fourth corrugated steel plate 14 is wave pitch × wave height × wall thickness = 400mm × 150mm × 5mm; the first corrugated steel plate 11 has one specification, and the arc length is 3 meters; the second corrugated steel plate 12 and the third corrugated steel plate 13 have two specifications, and the arc lengths are 1.5 meters and 3.0 meters respectively.

[0053] A shear nail 5 is welded at the trough of the back side of the corrugated steel plate member. The shear nail 5 is a round head bolt with a diameter of 10 mm and a length of 100 mm.

[0054] The steel tube-concrete composite beam 2 includes an annular steel tube and concrete 23 in the tube, and the concrete 23 in the tube is poured into the interior of the steel tube; the steel tube is assembled from steel tube components 21, and the steel tube components 21 are provided with a socket structure 213, a second bolt hole 214, a reserved hole 211 and a second grouting hole 212. The steel tube components 21 are assembled together through the socket structure 213, the reserved hole 211 is used to support the advance small guide tube 22, and the second grouting hole 212 is used to grout into the interior of the steel tube. The socket structures 213 and the steel tube and the corrugated steel plate are connected by high-strength bolts 6.

[0055] The advance small conduit 22 is made of a seamless steel pipe with a diameter of 38mm-50mm; the front end of the advance small conduit 22 is a 10cm long cone, and there is no hole within the rear end 100cm, and the remaining part is arranged with overflow holes with a diameter of 6mm in a plum blossom shape of 20 to 30cm.

[0056] The H-shaped steel supporting structure 3 includes an H-shaped steel 31 and a locking anchor rod 32, and the web of the H-shaped steel 31 is provided with a stiffening rib 312 and a locking anchor rod hole 311; a hole is drilled into the surrounding rock through the locking anchor rod hole 311, and the locking anchor rod 32 is inserted into the surrounding rock, so as to fix the H-shaped steel 31 on the surrounding rock; end connecting plates 313 are welded at both ends of the H-shaped steel 31, and the end connecting plates 313 are provided with bolt holes three 314; the upper and lower flange parts of the H-shaped steel 31 are provided with bolt holes four 315; high-strength bolts 6 are used to connect the H-shaped steels 31, between the H-shaped steel 31 and the corrugated steel plate, and between the H-shaped steel 31 and the steel tube-concrete composite beam 2.

[0057] Example 1

[0058] The construction method of the above-mentioned assembled corrugated steel-filling layer composite tunnel support system comprises the following steps:

[0059] 1) Carry out advanced support operations:

[0060] The steel pipe components 21 are first spliced ​​at the tunnel entrance. The steel pipe components 21 are connected by the socket structure 213, and the splicing construction is carried out from one side to the other side in sequence. After the steel pipe components 21 are assembled, holes are drilled into the surrounding rock through the reserved holes 211, and then the advance small guide tubes 22 are driven into the surrounding rock. Then, the advance small guide tubes 22 are grouted to realize the advance support operation during the construction process.

[0061] 2) Carry out the upper step support construction:

[0062] First, the upper step part of the tunnel is excavated, and the core soil part is retained; after the excavation is completed, the H-shaped steel 31 is installed, and the H-shaped steel 31 is installed at the elevation position of the arch foot, and a hole is drilled into the surrounding rock through the locking foot anchor hole 311, and then the locking foot anchor 32 is driven into the surrounding rock to fix the H-shaped steel 31, and then the steel pipe member 21 is connected to the H-shaped steel by high-strength bolts;

[0063] Then, the corrugated steel plates are assembled. The first corrugated steel plate 11 is assembled from both sides to the arch top. The first corrugated steel plate 11 is connected to the H-shaped steel 31 on both sides of the arch foot, and the first corrugated steel plate 11 is connected to the steel pipe member 21 through high-strength bolts 6; after the first corrugated steel plate 11 is assembled, the third corrugated steel plate 13 is assembled. After the third corrugated steel plate 13 is assembled, the second corrugated steel plate 12 is assembled, and the second corrugated steel plate 12 is connected to the steel pipe member 21 of the next ring through high-strength bolts 6; the third corrugated steel plate 13 and the second corrugated steel plate 12 are connected to the H-shaped steel 31 on both sides of the arch foot; the first corrugated steel plate 11, the third corrugated steel plate 13, and the second corrugated steel plate 12 are connected through high-strength bolts 6; the corrugated steel plates are assembled by staggered assembly;

[0064] 3) Carry out tunnel lower step construction:

[0065] The core soil part of the upper step and the lower step of the tunnel are excavated; after the excavation is completed, the fourth corrugated steel plate 14 is assembled, and the assembly order is symmetrical from both sides to the bottom. The fourth corrugated steel plates 14 on both sides of the lower step are connected to the H-shaped steel 31 through high-strength bolts 6, so that the corrugated steel plates of the upper and lower steps form a closed annular whole. After assembling one ring, the tunnel support construction of the next ring is carried out along the longitudinal construction;

[0066] 4) Carry out grouting construction:

[0067] After the corrugated steel plate is assembled, concrete slurry is poured into the steel pipe component 21 through the grouting hole 212 to form the inner concrete 23; then, concrete slurry is poured into the back of the corrugated steel plate through the grouting hole 17, and the grouting sequence is from both sides to the middle along the longitudinal construction direction to form a concrete filling layer 15; the corrugated steel plate forms a combined structure with the concrete filling layer 15 through the shear nails 5, and after the concrete is initially set, a complete assembled corrugated steel-filling layer composite tunnel support system is formed.

[0068] Example 2

[0069] The difference from Example 1 is that, in the construction method of the assembled corrugated steel-filling layer composite tunnel support system, the steel pipe component 21 is assembled in a full-ring structure, and the fourth corrugated steel plate 14 is connected to the steel pipe component 21 by high-strength bolts 6.

Claims

1. An assembled corrugated steel-filling layer composite tunnel support system, characterized in that: It includes a corrugated steel-filling layer composite plate, a steel tube-concrete composite beam, an advance small conduit and an H-shaped steel supporting structure; the steel tube-concrete composite beam is a connecting member arranged between the upper corrugated steel-filling layer composite plate and the lower corrugated steel-filling layer composite plate; the corrugated steel-filling layer composite plate includes an upper step part and a lower step part, which are combined together by an H-shaped steel supporting structure, and the end of the H-shaped steel supporting structure is fixedly connected to the steel tube-concrete composite beam by high-strength bolts; a plurality of advance small conduits penetrate the steel tube-concrete composite beam and are inserted in front of the tunnel excavation face, and the tail end of the advance small conduit is arranged on the steel tube-concrete composite beam, and the angle between the advance small conduit and the corrugated steel-filling layer composite plate is 8~ 12°; the corrugated steel-filling layer composite plate includes a corrugated steel plate and a concrete filling layer; shear nails are welded at the trough on the back of the corrugated steel plate component to improve the anti-slip performance between the corrugated steel plate and the concrete filling layer; the steel tube-concrete composite beam includes an annular steel tube and concrete in the tube, and the concrete in the tube is poured inside the steel tube; the steel tube is assembled from steel tube components, and the steel tube component is provided with a socket structure, two bolt holes, a reserved hole and two grouting holes, and the steel tube components are assembled together through the socket structure; the reserved hole is used to support the advance small guide tube, and the two grouting holes are used to grout into the inside of the steel tube; the socket structures and the steel tube and the corrugated steel plate are connected by high-strength bolts.

2. The assembled corrugated steel-filling layer composite tunnel support system according to claim 1 is characterized in that: The corrugated steel plate has a reserved grouting hole, and grouting is performed behind the corrugated steel plate through a pair of grouting holes to form a concrete filling layer between the back of the corrugated steel plate and the interface of the surrounding rock; the corrugated steel plate and the concrete filling layer form a combined structure to bear force together to improve the supporting capacity.

3. The assembled corrugated steel-filling layer composite tunnel support system according to claim 2 is characterized in that: The edge of the corrugated steel plate is welded with a flange; a bolt hole is reserved on the flange; the multiple corrugated steel plates are connected and staggeredly assembled by high-strength bolts.

4. The assembled corrugated steel-filling layer composite tunnel support system according to claim 3 is characterized in that: The corrugated steel plates are respectively the first corrugated steel plate, the second corrugated steel plate, the third corrugated steel plate and the fourth corrugated steel plate; the upper step part of the corrugated steel-filling layer composite plate is formed by combining and connecting the first corrugated steel plate, the second corrugated steel plate and the third corrugated steel plate, and the two ends of the third corrugated steel plate are respectively connected to the first corrugated steel plate and the second corrugated steel plate; the lower step part of the corrugated steel-filling layer composite plate is composed of the fourth corrugated steel plate.

5. The assembled corrugated steel-filling layer composite tunnel support system according to claim 4 is characterized in that: The first corrugated steel plate and the second corrugated steel plate are both connected between the steel tube-concrete composite beam and the third corrugated steel plate, and the properties of the two are transitional corrugated steel plates; the waveforms of the first corrugated steel plate and the second corrugated steel plate are transitional waves between large waveforms and small waveforms, the size of the large waveform is consistent with that of the third corrugated steel plate, and the size of the small waveform is smaller than that of the third corrugated steel plate; the first corrugated steel plate and the second corrugated steel plate play a transitional role between the steel tube-concrete composite beam and the third corrugated steel plate, effectively reducing the angle of the leading small duct and avoiding collision between the corrugated steel plate and the leading small duct during construction.

6. The assembled corrugated steel-filling layer composite tunnel support system according to claim 5 is characterized in that: The H-shaped steel supporting structure includes an H-shaped steel and a locking anchor rod; the web of the H-shaped steel is provided with a stiffening rib and a locking anchor rod hole; a hole is drilled into the surrounding rock through the locking anchor rod hole, and the locking anchor rod is inserted into the surrounding rock after passing through the locking anchor rod hole, so as to fix the H-shaped steel on the surrounding rock; end connecting plates are welded at both ends of the H-shaped steel, and the end connecting plates are provided with bolt holes three; bolt holes four are provided on the upper and lower flange parts of the H-shaped steel; high-strength bolts are used to connect the H-shaped steels, between the H-shaped steel and the corrugated steel plate, and between the H-shaped steel and the steel tube-concrete composite beam.

7. The construction method of the assembled corrugated steel-filling layer composite tunnel support system according to claim 6 comprises the following steps: 1) Carry out advanced support operations: The steel pipe components are first spliced ​​at the tunnel entrance. The steel pipe components are connected by the socket structure and the splicing construction is carried out from one side to the other side in sequence. After the steel pipe components are assembled, holes are drilled into the surrounding rock through the reserved holes, and then the advance small guide tube is driven into the surrounding rock. Then, the advance small guide tube is grouted to realize the advance support operation during the construction process. 2) Carry out the upper step support construction: First, the upper step part of the tunnel is excavated, and the core soil part is retained; after the excavation is completed, the H-shaped steel is installed, and the H-shaped steel is installed at the elevation position of the arch foot, and a hole is drilled into the surrounding rock through the locking foot anchor hole, and then the locking foot anchor is driven into the surrounding rock to fix the H-shaped steel, and then the steel pipe component and the H-shaped steel are connected by high-strength bolts; Then, the corrugated steel plates are assembled. The first corrugated steel plate is assembled from both sides to the arch top. The first corrugated steel plate is connected to the H-shaped steel on both sides of the arch foot, and the first corrugated steel plate is connected to the steel pipe member through high-strength bolts; after the first corrugated steel plate is assembled, the third corrugated steel plate is assembled. After the third corrugated steel plate is assembled, the second corrugated steel plate is assembled, and the second corrugated steel plate is connected to the steel pipe member of the next ring through high-strength bolts; the third corrugated steel plate and the second corrugated steel plate are connected to the H-shaped steel on both sides of the arch foot; the first corrugated steel plate, the third corrugated steel plate, and the second corrugated steel plate are connected by high-strength bolts; the corrugated steel plates are assembled by staggered assembly; 3) Carry out tunnel lower step construction: Excavate the core soil of the upper step and the lower step of the tunnel; after the excavation is completed, assemble the fourth corrugated steel plate in a symmetrical manner from both sides to the bottom. The fourth corrugated steel plate on both sides of the lower step is connected to the H-shaped steel by high-strength bolts, so that the corrugated steel plates of the upper and lower steps form a closed ring-shaped whole. After assembling one ring, carry out the tunnel support construction of the next ring along the longitudinal construction; 4) Carry out grouting construction: After the corrugated steel plates are assembled, concrete slurry is poured into the steel pipe components through grouting holes 2 to form concrete inside the pipe; then, concrete slurry is poured behind the corrugated steel plates through grouting holes 1, and the grouting sequence is from both sides to the middle along the longitudinal construction direction to form a concrete filling layer; the corrugated steel plates form a combined structure with the concrete filling layer through the shear nails, and after the concrete is initially set, a complete assembled corrugated steel-filling layer composite tunnel support system is formed.

8. The construction method of the assembled corrugated steel-filling layer composite tunnel support system according to claim 7 is characterized by: The steel pipe is assembled in a half ring or a full ring.

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