Loose roadway surface totally-closed surface protection supporting structure and construction method

Abstract

The invention provides a loose roadway surface totally-closed surface protection supporting structure and a construction method. The full-closed surface protection supporting structure comprises a high-strength flexible steel plate which is laid on the surface of a roadway in a full-surrounding mode, a set of anchor cable holes are reserved in the first position of the high-strength flexible steel plate in the longitudinal direction of the roadway, and a set of anchor rod holes are reserved in the second position of the high-strength flexible steel plate in the longitudinal direction of the roadway; the multiple sets of W-shaped steel belts are laid at the first positions of the high-strength flexible steel plates in the longitudinal direction of the roadway, and a set of corresponding anchor cable holes are reserved in the W-shaped steel belts in the longitudinal direction of the roadway; each group of high-strength anchor cables penetrate through the W-shaped steel belts and the anchor cable holes in the high-strength flexible steel plates and are anchored in the surrounding rock of the roadway; and each group of high-strength anchor rods penetrate through the anchor rod holes in the high-strength flexible steel plates and are anchored in the surrounding rock of the roadway. The supporting problem caused by surface breaking, falling and the like of an extremely loose roadway is solved through internal and external treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, in particular to tunnel excavation support, and specifically to a fully enclosed surface protection support structure for a loose tunnel surface and a construction method. Background Art

[0002] During the excavation process of coal mine tunnels, for extremely loose and broken coal seam tunnels, due to the broken surface of the tunnel, after the construction of anchor rods and cables, it is very easy for the surface coal body to break and fall, causing the preload force applied by the anchor rods and cables to be released and fail.

[0003] The existing steel mesh anchor spraying fully enclosed surface protection support structure has a large mesh and cannot hold small rock chips. As for shotcrete, the coal body is loose and is broken by the pressure of spraying, so it cannot be effectively bonded and is not easy to adhere to the surface of the tunnel. In addition, it may hang on the metal mesh, resulting in voids between the tunnel surrounding rock and posing a safety hazard.

[0004] In view of this, it is urgent to improve the current traditional fully enclosed surface support structure to solve the problem of loose tunnel surface management in a targeted manner. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a fully enclosed surface protection support structure and a construction method for a loose tunnel surface, which solves the support problems caused by surface crushing, falling, etc. in extremely loose tunnels by treating both the inside and the outside.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention first provides a fully enclosed surface protection support structure for a loose tunnel surface, and the fully enclosed surface protection support structure comprises: a high-strength flexible steel plate, which is fully surrounded and laid on the tunnel surface, and a group of anchor cable holes are reserved at a first position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, and a group of anchor rod holes are reserved at a second position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, the second positions are symmetrically distributed on both sides of the first position, and multiple groups of anchor cable holes and anchor rod holes are arranged in the entire section of the tunnel; multiple groups of W steel belts, multiple groups of W steel belts are laid at the first position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, and a group of corresponding anchor cable holes are reserved on the W steel belt along the longitudinal direction of the tunnel; multiple groups of high-strength anchor cables, each group of the high-strength anchor cables passes through the anchor cable holes on the W steel belt and the high-strength flexible steel plate, and is anchored in the tunnel surrounding rock; multiple groups of high-strength anchor rods, each group of the high-strength anchor rods passes through the anchor rod holes on the high-strength flexible steel plate, and is anchored in the tunnel surrounding rock.

[0008] The present invention also provides a construction method according to the fully enclosed surface protection support structure, comprising: S10, making a high-strength flexible steel plate, opening an anchor hole at a preset first position, opening an anchor rod hole at a preset second position, and opening multiple groups of the anchor hole and the anchor rod hole according to design requirements; at the same time, fixing reinforcing plates on both sides of the anchor rod hole at the second position; making a W steel belt, and opening anchor holes at preset positions on it; S20, manually excavating the top of the tunnel; S30, after the excavation of the top of the tunnel is completed, manually excavating a pilot groove along the top of the face, inserting the front of the high-strength flexible steel plate into the pilot groove, aligning the rear anchor rod hole, and fixing the rear with high-strength bolts high-strength flexible steel plate at the top; S40, according to the positions of the reserved anchor holes on the high-strength flexible steel plate, drill holes in the surrounding rock of the tunnel, and install the anchors through the reserved anchor holes to the top of the tunnel; S50, while performing step S40, manually excavate the side of the tunnel; S60, after the excavation of the side of the tunnel is completed, fix the high-strength flexible steel plate of the side in the same way; S70, according to the positions of the reserved anchor holes on the high-strength flexible steel plate, drill holes in the surrounding rock of the tunnel, and install the anchors through the reserved anchor holes to the side of the tunnel; S80, according to the support plan, after the W steel belt is excavated, arrange the W steel belt at the first position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, and drive the anchor cable.

[0009] The beneficial effects of the present invention compared with the prior art are: the present invention provides a fully enclosed surface protection support structure and construction method for a loose tunnel surface, including a bendable high-strength flexible steel plate (can be artificially bent into an arc shape), anchor rods (anchor cables), and W steel belts. Holes are prefabricated according to the support design plan for installing anchor rods and anchor cables, solving the support problems caused by surface crushing and falling in extremely loose tunnels. It has at least the following advantages and effects:

[0010] The fully enclosed surface protection support structure provided by the present invention is particularly suitable for tunnels with extremely loose and broken surrounding rocks. The bendable high-strength flexible steel plate (which can be artificially bent into an arc shape) can fully enclose the surrounding rock and prevent the safety hazards caused by the loose and broken coal body breaking and falling.

[0011] The fully enclosed surface protection support structure provided by the present invention is provided with a W steel belt outside the high-strength flexible steel plate. The W steel belt has greater strength and can transmit the anchoring force between the anchor cables to form a whole, thereby playing a role in enhancing support and solving the problem of insufficient supporting force of the flexible steel plate.

[0012] The fully enclosed surface protection support structure provided by the present invention transmits the anchoring force to the deep surrounding rock with the help of anchor cables, and at the same time transmits it to the surrounding rock more evenly through high-strength flexible steel plates, which can prevent the failure of the anchor cables due to surrounding rock crushing and achieve the purpose of strong surface protection of the tunnel and joint treatment of the inside and outside.

[0013] The fully enclosed surface protection support structure provided by the present invention has reserved grouting holes in the W steel belt, and expansive concrete can be poured in the later stage. The gaps are filled with expansive concrete to prevent the surrounding rock in the gaps from loosening and falling off, resulting in the release of the preload force applied by the anchor cable, and then causing the anchor cable to fail.

[0014] It should be understood that the implementation of any embodiment of the present invention does not mean that multiple or all of the above-mentioned beneficial effects must be possessed or achieved at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0016] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment in size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0017] Figure 1 A schematic plan view of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is exemplarily shown;

[0018] Figure 2 A schematic diagram showing the deformation of a high-strength flexible steel plate of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is exemplified;

[0019] Figure 3 A schematic diagram of radial overlap of high-strength flexible steel plates of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is exemplified;

[0020] Figure 4 A schematic diagram of a full cross-section plane of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is shown as an example;

[0021] Figure 5 A schematic diagram of a full-section elevation of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is shown as an example;

[0022] Figure 6 A schematic diagram showing the local grouting effect of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is exemplified;

[0023] Figure 7 The flowchart of the construction method of a fully enclosed surface protection support structure for a loose tunnel surface provided by the present invention is exemplarily shown;

[0024] Figure 8 A schematic diagram of a loose tunnel surface is shown as an example.

[0025] Markings in the figure:

[0026] 1-high-strength flexible steel plate, 2-W steel strip, 3-reinforcement plate, 4-grouting hole, 5-high-strength anchor rod, 6-high-strength anchor cable, 7-anchor rod hole, 8-anchor cable hole, 9-high-strength bolt, 10-tunnel, 11-expansive concrete, 12-crease groove.

[0027] The same or corresponding symbols in the drawings indicate the same or corresponding parts. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with the embodiments and drawings. Here, the illustrative embodiments of the present invention and their description are used to explain the present invention, but are not intended to limit the present invention.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] It should be understood that the terms "include / comprise", "consist of..." or any other variations are intended to cover non-exclusive inclusion, so that a product, device, process or method that includes a series of elements includes not only those elements, but also may include other elements not explicitly listed when necessary, or also includes elements inherent to such product, device, process or method. In the absence of more restrictions, the elements defined by the sentence "include / comprise...", "consist of..." do not exclude the presence of other identical elements in the product, device, process or method that includes the elements.

[0031] It is also necessary to understand that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device, component or structure must have a specific direction, be constructed or operate in a specific direction, and should not be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Glossary:

[0034] A coal seam tunnel is a road that advances parallel to the plane of the coal seam, is dug into the coal seam and remains in the coal seam.

[0035] Loose tunnels (or extremely loose tunnels) refer to tunnels with extremely poor geological conditions and extremely broken surrounding rocks. The surrounding rock coal body is compressed and consolidated into blocks. It is easy to break with light pressure from fingers and has squeezing and kneading phenomena. The surrounding rock of such tunnels cannot stabilize itself, and strong support measures are required to maintain the stability of the tunnel.

[0036] The longitudinal direction of the tunnel refers to the excavation direction along the tunnel.

[0037] The transverse direction of the tunnel refers to the direction along the cross section of the tunnel.

[0038] During the excavation of coal mine tunnels, for extremely loose and broken coal seam tunnels, the tunnel surface is broken and easily broken by light pressure of fingers, with extrusion and rubbing phenomena. After the construction of anchor bolts and cables, the surface coal body is very likely to break and fall off, causing the preload force applied by the anchor bolts and cables to be released and then fail. Figure 8 shown.

[0039] In view of the characteristics of loose tunnels, the present invention uses high-strength flexible steel plates to fully seal the surrounding rock surface, and performs grouting filling between the high-strength flexible steel plates and the surrounding rock, combined with anchor rods and anchor cables to achieve inside and outside treatment, so as to solve the support problems caused by surface crushing and falling in extremely loose tunnels.

[0040] The implementation of the present invention is described in detail below in conjunction with preferred embodiments.

[0041] See also Figure 1-6 ,in Figure 1 A schematic plan view of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown. Figure 2A schematic diagram showing the deformation of a high-strength flexible steel plate of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown. Figure 3 A schematic diagram of radial overlap of high-strength flexible steel plates of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown. Figure 4 A schematic diagram of a full cross-section plane of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown. Figure 5 A schematic elevation diagram of a full-section of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown. Figure 6 A schematic diagram showing the local grouting effect of a fully enclosed surface protection support structure for a loose tunnel surface provided by an embodiment of the present invention is shown.

[0042] See also Figure 1 , 2 The fully enclosed surface protection support structure mainly includes: high-strength flexible steel plate 1, W steel belt 2, high-strength anchor 5, and high-strength anchor cable 6. The high-strength flexible steel plate fully encloses the surrounding rock surface to prevent the safety hazards caused by the loose and broken coal body breaking and falling. The anchor cable is installed to increase the contact area between the anchor cable and the surrounding rock of the tunnel, so that the force of the anchor cable is more evenly transmitted to the surrounding rock through the high-strength flexible steel plate. The high-strength flexible steel plate seals the surrounding rock and prevents the anchor cable from failing due to the crushing of the surrounding rock. In this way, the purpose of "strong surface protection and joint treatment of the inside and outside" of the tunnel is achieved.

[0043] Specifically, see Figure 1 , 2 , 4, 5, the high-strength flexible steel plate 1 is laid on the surface of the tunnel 10 in a fully enclosed manner. The so-called fully enclosed means that the surface of the tunnel 10 is fully enclosed to prevent the loose and broken rock from falling, and the high-strength flexible steel plate 1 has a group of anchor holes 8 reserved along the longitudinal direction of the tunnel at its first position, and a group of anchor holes 7 reserved along the longitudinal direction of the tunnel at its second position. The second position is symmetrically distributed on both sides of the first position, and multiple groups of anchor holes 8 and anchor holes 7 are arranged in the entire section of the tunnel.

[0044] See Figure 1 , 4 The first position is preferably selected in the middle of a high-strength flexible steel plate 1, and then the second position is symmetrically selected on the left and right sides thereof or even slightly farther away. That is to say, a group of anchor holes 8 are pre-opened in the middle of a high-strength flexible steel plate 1, and two rows of anchor holes 7 are symmetrically opened on the left and right sides of the anchor holes 8. One or more rows of anchor holes 7 can be symmetrically opened outward as needed.

[0045] For the W steel belt 2, a group of W steel belts 2 are arranged at the first position where a group of anchor cable holes 8 are located, and multiple groups of W steel belts 2 are laid at the first position of the high-strength flexible steel plate 1 along the longitudinal direction of the tunnel, and a group of anchor cable holes 8 are reserved on the W steel belt 2 along the longitudinal direction of the tunnel, and the group of anchor cable holes 8 corresponds to a group of anchor cable holes 8 on the high-strength flexible steel plate 1 one by one, so as to facilitate the laying and installation of anchor cables. Since the main function of the flexible steel plate is to seal the surrounding rock and does not provide much support force, the present invention adds a W steel belt 2 outside the high-strength flexible steel plate 1. The W steel belt has greater strength and can transmit the anchoring force between the anchor cables, making it a whole, and playing a role in enhancing support.

[0046] like Figure 2 , corresponding to a group of anchor cable holes 8, a group of high-strength anchor cables 6 are set, and each group of high-strength anchor cables 6 passes through the anchor cable holes 8 on the W steel belt 2 and the high-strength flexible steel plate 1 in turn, and is anchored in the tunnel surrounding rock; at the same time, corresponding to a group of anchor rod holes 7, a group of high-strength anchor rods 5 are set, and each group of high-strength anchor rods 5 passes through the anchor rod holes 7 on the high-strength flexible steel plate 1 and is anchored in the tunnel surrounding rock. In this way, with the help of the anchor rod cable, the anchoring force is transmitted to the deep surrounding rock, and at the same time, it is more evenly transmitted to the surrounding rock through the high-strength flexible steel plate, which can prevent the anchor cable from failing due to the crushing of the surrounding rock, and achieve the purpose of strong protection of the tunnel surface and co-treatment of the surface and inside.

[0047] In some specific embodiments, see Figure 1 A grouting hole 4 is reserved on the W steel belt 2 along the longitudinal direction of the roadway, and a group of grouting holes is reserved at the first position of the high-strength flexible steel plate 1 along the longitudinal direction of the roadway. For loose roadway surrounding rock, the roadway surface is usually very uneven, and the expansion concrete 11 can be poured into the gap between the surrounding rock and the high-strength flexible steel plate 1 through the reserved grouting holes 4, such as Figure 6 As shown, the gap is filled with expansion concrete 11 to prevent the surrounding rock in the gap from loosening and falling off. Almost no pressure is required during the pouring process, which can prevent damage to the surrounding rock.

[0048] The grouting holes 4 and the anchor holes 8 on the W steel strip 2 and the high-strength flexible steel plate 1 are arranged alternately. Figure 1 As shown, three anchor holes 8 are reserved on a W-shaped steel belt 2, and two grouting holes 4 are arranged alternately at intervals, which do not affect each other and can ensure that all the surrounding rocks behind the entire high-strength flexible steel plate 1 can be filled.

[0049] In addition, the grouting hole 4 is set at the W steel belt 2, and the gap behind the high-strength flexible steel plate 1 is filled from this position, and then expanded to the adjacent area, which can ensure the filling strength behind the W steel belt 2 and ensure the effective anchoring of the high-strength anchor cable 6 here in the later stage.

[0050] In some specific embodiments, see Figure 2 , 3The high-strength flexible steel plate 1 has one or more crease grooves 12, and the crease grooves 12 extend longitudinally along the lane. By setting the crease grooves, along the crease direction, since the crease is not easy to bend, the section modulus can be effectively improved, and the bending resistance and bearing capacity of the flexible steel plate along the longitudinal direction can be enhanced, so that it can resist deformation. In the vertical crease direction, since the wall of the flexible steel plate is thin, it can be bent, so it can be suitable for lanes with various cross-sectional shapes such as circular, rectangular, straight wall semi-circular arch, etc. (the straight wall semi-circular arch section is taken as an example in the present invention), the shape is easy to process, and does not affect the bending deformation requirements of the flexible steel plate.

[0051] In some specific embodiments, see Figure 3 The high-strength flexible steel plate 1 is composed of multiple pieces in the whole section of the tunnel. Two adjacent high-strength flexible steel plates 1 are overlapped together by the fold groove 12 in the horizontal direction, and the two sides of the fold groove 12 are connected and fixed with high-strength bolts 9, so that the high-strength flexible steel plate 1 is connected as a whole in the whole section of the tunnel. During on-site laying, the fold grooves 12 of the two adjacent high-strength flexible steel plates 1 are embedded and overlapped, and then the two sides of the fold groove 12 are respectively connected and fixed with high-strength bolts 9, and a group is laid for each excavation advance. By embedding the fold grooves at the overlapped part and connecting with the help of bolts, the connection strength here is ensured, and at the same time, the bendability of the overlapped part is not affected. Even if multiple flexible steel plates are connected and assembled, a continuous and predetermined cross-sectional shape can be obtained relatively easily.

[0052] Preferably, the cross section of the fold groove 12 is arc-shaped, such as semicircular, to facilitate processing and shaping, as well as to facilitate on-site overlapping and interlocking construction.

[0053] See also Figure 1 The high-strength anchor rod 5 is directly anchored on the high-strength flexible steel plate 1 at the anchor rod hole at the second position of the high-strength flexible steel plate 1. Since the wall of the high-strength flexible steel plate 1 is relatively thin, in order to ensure that effective anchoring can be formed here, the present invention pre-fixes the reinforcing plate 3 here to prevent stress concentration when installing the high-strength anchor rod 5. The reinforcing plate 3 can be a square steel plate, and the cross-sectional size and thickness are set according to the actual force, and a hole is reserved in the center to penetrate the high-strength anchor rod 5.

[0054] Preferably, the thickness of the high-strength flexible steel plate 1 is 3-5 mm.

[0055] Since the thickness of the flexible steel plate is relatively thin, in order to reduce stress concentration, the reinforcing plate 3 adopts a double-layer structure, and two reinforcing plates 3 are respectively fixed to the front and back surfaces of the high-strength flexible steel plate 1 at the anchor holes at the second position.

[0056] In some specific embodiments, a polyethylene foam layer (not shown in the figure) may be pre-pasted on the inner surface of the high-strength flexible steel plate 1. The polyethylene foam layer has high compressibility to provide flexible contact on the tunnel surface, fill part of the gap with the tunnel surface, and improve the energy absorption capacity of the flexible steel plate.

[0057] The present invention further provides a construction method for the fully enclosed surface protection support structure described above, such as Figure 7 The flowchart shown includes:

[0058] S10, firstly, the plate is processed and manufactured, that is, a high-strength flexible steel plate 1 is manufactured, and the positions and numbers of the anchor holes 8 and the anchor rod holes 7 are arranged on the flexible steel plate according to the size of each flexible steel plate, and the anchor holes 8 are opened at the preset first position, and the anchor rod holes 7 are opened at the preset second position; in the present invention, preferably, a group of three anchor holes 8 are opened in the middle of each flexible steel plate along the longitudinal direction of the lane, a group of two anchor rod holes 7 are opened on each of the left and right sides, and two grouting holes 4 are opened alternately between the three anchor holes 8; at the same time, the reinforcing plate 3 is fixed on both sides of the anchor rod hole 7 at the second position; a W steel belt 2 is manufactured, and anchor holes 8 are opened on it at the preset positions, and the anchor holes 8 correspond to the anchor holes 8 on the high-strength flexible steel plate 1 one by one;

[0059] The high-strength flexible steel plate 1 is used in combination of multiple pieces, and anchor cable holes 8 and anchor rod holes 7 are respectively opened, and the plates are ready for use.

[0060] S20, top of manually excavated tunnel;

[0061] Since the coal body surrounding the tunnel is too loose, manual excavation can minimize the disturbance to the surrounding rock.

[0062] S30, after the top of the tunnel 10 is excavated, a pilot groove is artificially excavated along the top of the face, the front of the high-strength flexible steel plate 1 is inserted into the pilot groove, aligned with the rear anchor hole 7, and fixed with high-strength bolts at the rear, so that the high-strength flexible steel plate 1 at the top is temporarily fixed;

[0063] S40, drilling holes in the surrounding rock of the tunnel according to the positions of the anchor holes reserved on the high-strength flexible steel plate 1, and installing the high-strength anchor 5 through the reserved anchor holes 7 to the top of the tunnel (a grout stopper can be installed at the hole at this time), thus completing the installation of the high-strength flexible steel plate 1 on the top of the tunnel;

[0064] If the surface of the tunnel surrounding rock is extremely uneven, expansive concrete 11 is poured into the gap between the surrounding rock and the high-strength flexible steel plate 1 through the reserved grouting holes 4. Basically, no pressure is required during the pouring process to prevent damage to the surrounding rock.

[0065] S50, while performing step S40, manually excavating the side of the tunnel;

[0066] S60, after the tunnel side is excavated, the high-strength flexible steel plate 1 of the side is fixed in the same way;

[0067] S70, according to the position of the anchor hole 7 reserved on the high-strength flexible steel plate 1, drill holes in the surrounding rock of the tunnel, and install the high-strength anchor 5 through the reserved anchor hole 7 to the tunnel side (at this time, a grout stopper can be installed at the hole), thus completing the installation of the high-strength flexible steel plate 1 on the tunnel side;

[0068] S80. Finally, according to the support plan, after the excavation reaches the footage corresponding to the W steel belt 2, the W steel belt 2 is arranged at the first position of the high-strength flexible steel plate 1 along the longitudinal direction of the tunnel, and the high-strength anchor cable 6 is installed.

[0069] It is obvious from the above detailed description that the fully enclosed surface protection support structure provided by the present invention is especially aimed at extremely loose and broken surrounding rock tunnels, including bendable high-strength flexible steel plates (can be artificially bent into an arc shape), anchor rods (anchor cables), and W steel belts. Holes are prefabricated according to the support design plan for installing anchor rods and anchor cables, combined with the W steel belts arranged along the longitudinal direction and reserved grouting holes, and expansive concrete can be poured in the later stage. The high-strength flexible steel plate can fully seal the surrounding rock to prevent the safety hazards caused by the loose and broken coal body breaking and falling. Install the anchor cable to increase the contact area between the anchor cable and the surrounding rock of the tunnel, so that the force of the anchor cable is more evenly transmitted to the surrounding rock through the high-strength flexible steel plate, and the high-strength flexible steel plate seals the surrounding rock, and at the same time can prevent the failure of the anchor cable due to the crushing of the surrounding rock. The purpose of strong surface protection of the tunnel and co-treatment of the inside and outside is achieved.

[0070] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0071] Although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the present invention. Certain features described in the context of separate embodiments may also be implemented in a single implementation in combination. On the contrary, the various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable sub-combination.

Claims

1. A fully enclosed surface protection support structure for loose tunnel surface, characterized in that: The fully enclosed surface protection support structure includes: A high-strength flexible steel plate, wherein the high-strength flexible steel plate is fully surrounded and laid on the surface of the tunnel, and a group of anchor cable holes are reserved at a first position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, and a group of anchor rod holes are reserved at a second position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, the second position is symmetrically distributed on both sides of the first position, and the anchor cable holes and anchor rod holes are arranged in multiple groups in the entire cross-section of the tunnel; A plurality of groups of W steel belts, wherein the plurality of groups of W steel belts are laid at the first position of the high-strength flexible steel plate along the longitudinal direction of the roadway, and a group of corresponding anchor cable holes are reserved on the W steel belts along the longitudinal direction of the roadway; A plurality of groups of high-strength anchor cables, each group of the high-strength anchor cables passes through the anchor cable holes on the W steel belt and the high-strength flexible steel plate and is anchored in the surrounding rock of the tunnel; A plurality of groups of high-strength anchor rods, each group of the high-strength anchor rods passes through the anchor rod holes on the high-strength flexible steel plate and is anchored in the surrounding rock of the tunnel.

2. The fully enclosed surface protection support structure according to claim 1 is characterized in that: The W steel strip and the high-strength flexible steel plate are provided with a set of grouting holes corresponding to each other along the longitudinal direction of the tunnel at the first position, which are used for grouting and filling the expansion concrete between the high-strength flexible steel plate and the tunnel surrounding rock.

3. The fully enclosed surface protection support structure according to claim 1 is characterized in that: The high-strength flexible steel plate is provided with one or more crease grooves, and the crease grooves extend longitudinally along the lane.

4. The fully enclosed surface protection support structure according to claim 3 is characterized in that: The high-strength flexible steel plate is composed of multiple pieces within the entire cross-section of the tunnel. Two adjacent high-strength flexible steel plates are overlapped together in the transverse direction by folding grooves, and the two sides of the folding grooves are connected and fixed with high-strength bolts, so that the high-strength flexible steel plates are connected as a whole within the entire cross-section of the tunnel.

5. The fully enclosed surface protection support structure according to claim 3 is characterized in that: The cross section of the fold groove is arc-shaped.

6. The fully enclosed surface protection support structure according to claim 1 is characterized in that: The high-strength flexible steel plate is pre-fixed with a reinforcing plate at the anchor hole at the second position to prevent stress concentration when installing the high-strength anchor.

7. The fully enclosed surface protection support structure according to claim 6 is characterized in that: The reinforcing plate has a double-layer structure, and two reinforcing plate sheets are respectively fixed to the front and back surfaces of the high-strength flexible steel plate at the anchor holes at the second position.

8. The fully enclosed surface protection support structure according to claim 1 is characterized in that: A polyethylene foam layer is pasted on the inner surface of the high-strength flexible steel plate. The polyethylene foam layer is highly strong and compressible so as to provide flexible contact on the tunnel surface.

9. A construction method of the fully enclosed surface protection support structure according to any one of claims 1 to 8, characterized in that: include: S10, manufacturing a high-strength flexible steel plate, opening an anchor hole at a preset first position on the plate, opening an anchor rod hole at a preset second position, and opening multiple groups of the anchor hole and the anchor rod hole according to design requirements; fixing reinforcing plates on both sides of the anchor rod hole at the second position; manufacturing a W steel belt, and opening anchor holes at preset positions on the plate; S20, top of manually excavated tunnel; S30, after the top of the tunnel is excavated, a pilot groove is manually excavated along the top of the face, the front of the high-strength flexible steel plate is inserted into the pilot groove, aligned with the rear anchor hole, and the high-strength flexible steel plate at the top is fixed with high-strength bolts at the rear; S40, according to the position of the anchor hole reserved on the high-strength flexible steel plate, drill holes in the surrounding rock of the tunnel, and install the anchor through the reserved anchor hole to the top of the tunnel; S50, while performing step S40, manually excavating the side of the tunnel; S60, after the tunnel side is excavated, the high-strength flexible steel plate of the side is fixed in the same way; S70: Drill holes in the surrounding rock of the tunnel according to the positions of the anchor holes reserved on the high-strength flexible steel plate, and install the anchors through the reserved anchor holes to the side of the tunnel; S80, according to the support plan, after the W steel belt is excavated, the W steel belt is arranged at the first position of the high-strength flexible steel plate along the longitudinal direction of the tunnel, and the anchor cable is installed.

10. The construction method according to claim 9, characterized in that: After steps S40 and S70, expansive concrete is poured into the gap between the surrounding rock and the high-strength flexible steel plate through the reserved grouting holes, and stress sensors are installed on the inner side of the high-strength flexible steel plate at the obvious over-excavation position to monitor the steel plate pressure in real time during grouting to prevent excessive pressure from damaging the surrounding rock.

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