A shotcrete reinforcement structure and construction method

Abstract

The present invention discloses a shotcrete reinforcement structure and a construction method, which relate to the technical field of auxiliary projects. The structure includes a first concrete layer and a second concrete layer constructed successively. The first concrete layer is a rapid-hardening concrete constructed on the base layer by the shotcrete method. A deformation zone and a number of fixing plates are longitudinally arranged in the first concrete layer. Anchor bolts are provided on the surrounding rock, and one end of each anchor bolt is fixed on the fixing plate, and the fixing plate is fixed in the first concrete layer. After the construction of the first concrete layer, steel bars are arranged to construct the second concrete layer. In the shotcrete reinforcement structure of the present invention, the first concrete layer can provide good support for the base layer in a short time. The deformation zone is used to solve the disadvantage of poor deformation ability of the rapid-hardening concrete. The second concrete layer is constructed above the first concrete layer to enhance the strength in the later stage of support.

Description

Technical Field

[0001] The present invention relates to the technical field of auxiliary engineering, and particularly to a shotcrete reinforcement structure and a construction method thereof. Background Art

[0002] Shotcrete is a rapid concrete construction method, often used in combination with bolts as the primary support for tunnels. The New Austrian Tunneling Method is a way of tunnel construction. After blasting and excavation of the tunnel construction surface, due to the looseness of the rock mass itself and the influence of blasting vibration, etc., if the surrounding rock is not supported in time, disasters such as tunnel deformation, instability, and collapse may occur. In the prior art, shotcrete support is generally used. However, the early strength growth rate of ordinary Portland shotcrete is slow. In order to improve the setting speed of shotcrete, fly ash or other substances are added and accelerators are increased to form a rapid-hardening concrete. Although the early strength of this kind of concrete grows fast, due to the accelerators and other substances having an obvious influence on the later compressive strength and flexural strength of the shotcrete while playing the role of accelerating setting, brittle failure is likely to occur, and the anti-deformation ability is also significantly lower than that of ordinary concrete layers. Summary of the Invention

[0003] Aiming at the above deficiencies, the purpose of the present invention is to provide a solution to the problems that the early strength of ordinary shotcrete in support engineering grows slowly, while the later strength of rapid-hardening concrete is insufficient and brittle failure is easy to occur. The purpose of the present invention is also to provide a construction method for the above structure.

[0004] To this end, a shotcrete reinforcement structure of the present invention includes a first concrete layer and a second concrete layer constructed in sequence. The first concrete layer is a rapid-hardening concrete constructed on the base layer by the shotcrete method. A deformation zone and several fixing plates are longitudinally arranged in the first concrete layer. The base layer is provided with bolts, one end of the bolt is fixed on the fixing plate, and the fixing plate is fixed in the first concrete layer. After the construction of the first concrete layer, steel bars are arranged to construct the second concrete layer.

[0005] Further, the deformation zone is a rubber layer, both sides of the rubber layer are fixed by a frame, the frame is fixed on the fixing plate, and holes are provided on the fixing plates on both sides of the frame for fixing the bolts.

[0006] Further, connecting bars are fixedly connected to the fixing plates, and the connecting bars extend upward into the second concrete layer and are fixed to the steel bars in the second concrete layer.

[0007] The present invention also includes a construction method for the above-mentioned shotcrete reinforcement structure, wherein a guide rail parallel to the surface of the base layer is provided, a slider of a frame moves on the guide rail, a baffle is provided on the frame, the baffle is used to block the rebounding concrete, a moving device is provided on the baffle, the moving device can move along the baffle, a concrete spray gun is provided on the moving device and is used to spray concrete onto the base layer; when the first concrete layer is constructed, it starts from the lower part of the base layer, the moving device and the spray gun move along the length direction of the base layer to spray concrete, and after the concrete construction on the lower side is completed, the slider is moved again to drive the frame to move to the upper part of the base layer, and the mobile spray gun is moved along the length direction of the base layer again to spray concrete, and this is repeated until the construction of the first concrete layer in the corresponding area is completed.

[0008] Furthermore, the frame is provided with an upper limit portion and a lower limit portion at one end away from the base layer, and the upper limit portion and the lower limit portion include a limit plate protruding from the inner surface of the frame. The upper part of the frame forms the guide rail, and the slider is arranged between the upper limit portion and the lower limit portion.

[0009] Furthermore, the frame includes a bent portion, the bent portion bypasses the connecting rib, the frame includes a cross bar, the cross bar is connected to one end of the bent portion close to the base, and the baffle is provided on the cross bar.

[0010] Furthermore, the baffle is provided with a strip hole, the moving device is connected to both sides of the strip hole and moves along the strip hole, the moving device includes a moving plate, a nozzle is provided on the moving plate, the spray gun is inserted into the nozzle, and the position of the nozzle is opposite to the strip hole so that the concrete sprayed by the spray gun passes through the strip hole.

[0011] Furthermore, a side baffle is also provided on the frame, and the edge position of the side baffle is a predetermined distance away from the base layer or flush with the surface of the first concrete layer. When the frame moves along the guide track, the edge position of the side baffle can scrape the surface of the first concrete layer and make the surface thickness of the first concrete layer consistent.

[0012] Furthermore, the distance between the side baffle and the surrounding rock of the tunnel wall can be adjusted so that a multi-layer spraying construction method is adopted during the construction of the first concrete layer. After spraying a layer of concrete, the height of the side baffle is adjusted, and concrete is sprayed again before the lower layer of concrete solidifies. After repeating several times, the first concrete layer of a predetermined height is reached.

[0013] Furthermore, the second concrete layer is constructed by concrete pouring or concrete spraying, and the second concrete layer is made of concrete formed by mixing ordinary Portland cement, sand, crushed stone, water and admixtures.

[0014] Beneficial technical effects of the present invention:

[0015] A shotcrete reinforcement structure of the present invention can be used as the primary support of a tunnel or the support of a slope. Its structure includes two layers of concrete. The first concrete layer is formed by spraying fast-hardening concrete on the base layer (slope or tunnel surrounding rock), which has the characteristic of rapid strength growth and can provide good support to the base layer in a short time, shortening the construction interval. A deformation zone is longitudinally arranged in the first concrete layer to solve the disadvantage of poor deformation ability of fast-hardening concrete and prevent cracks or even brittle fracture in the first concrete layer due to deformation. The second concrete layer is constructed above the first concrete layer and uses ordinary concrete to enhance the strength in the later stage of support. The thickness of the second concrete layer can be several times that of the first concrete layer.

[0016] The present invention also includes a construction method of the above shotcrete reinforcement structure. By comprehensively setting baffles to solve the problem of concrete rebound and a spray gun moving along the baffle to ensure that the distance between the spray gun and the base layer is equal, the compactness of the shotcrete is consistent under the condition of constant spraying pressure. Side baffles are set to limit the thickness of the shotcrete and achieve a uniform thickness of the first concrete layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view schematic diagram of the deformation zone;

[0018] Figure 2 It is a left view schematic diagram of the deformation zone;

[0019] Figure 3 It is a front view schematic diagram of the deformation zone;

[0020] Figure 4 It is a schematic diagram of the baffle.

[0021] DESCRIPTION OF THE REFERENCE NUMERALS: 1, rubber layer; 2, frame; 201, upper limit part; 202, lower limit part; 3, fixing plate; 4, anchor bolt; 5, connecting rib; 6, bedrock; 7, first concrete layer; 8, slider; 9, frame; 901, bent part; 902, cross bar; 903, baffle; 904, side baffle; 905, moving plate; 906, spray nozzle; 907, strip hole. DETAILED DESCRIPTION OF THE INVENTION

[0022] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and their effects of the present invention as follows.

[0023] Refer to Figures 1 to 4As shown in the figure, a shotcrete reinforcement structure of the present invention includes a first concrete layer 7 and a second concrete layer constructed in sequence. The first concrete layer 7 is a rapid-hardening concrete constructed on the base layer by the shotcrete method. A deformation zone and several fixing plates 3 are longitudinally arranged in the first concrete layer 7. Anchor bolts 4 are provided on the surrounding rock, and one end of each anchor bolt 4 is fixed on the fixing plate 3. The fixing plate 3 is fixed in the first concrete layer 7. After the first concrete layer 7 is constructed, steel bars are arranged to construct the second concrete layer. In this embodiment, taking tunnel construction as an example, the panel of the first concrete layer 7 composed of the anchor bolts 4 and the shotcrete construction forms an anchor-shotcrete support. The anchor bolts 4 are first fixed on the fixing plates 3, and then concrete is sprayed to form the first concrete layer 7. The anchor-shotcrete support plays a role in supporting and reinforcing the surrounding rock and restricting the free development of the deformation of the surrounding rock. The first concrete layer uses rapid-hardening concrete. Both rapid-hardening concrete and ordinary shotcrete are existing technologies. Rapid-hardening concrete can be mixed by adding fly ash, more accelerating agents, and can use sulfoaluminate cement, crushed stones, sand, etc. Ordinary shotcrete generally uses Portland cement and certain accelerating agents and water-reducing agents and other admixtures. Of course, it also includes crushed stones, sand, etc. Rapid-hardening concrete has the characteristics of short initial setting time and rapid strength growth. The deformation zone can use a rubber layer, and the second concrete layer can use ordinary shotcrete, which is constructed after the first concrete layer 7 solidifies. The second concrete layer is used to improve the overall strength of the primary support and make up for the problem of insufficient strength of the first concrete layer 7. Among them, the thickness of the second concrete layer should be greater than that of the first concrete layer 7, such as 3 to 5 times, and the thickness of the first concrete layer 7 can be 50 mm.

[0024] In the above embodiment, referring to Figure 1 , Figure 2 and Figure 3 As shown, both sides of the rubber layer 1 are fixed by the frame 2. The frame 2 is fixed or integral with the fixing plate 3 at the bottom. The fixing plate 3 includes several fixing ears arranged on both sides, with holes in the middle of the fixing ears. The anchor bolts 4 pass through the fixing ears and are fixed on the fixing plate 3. The anchor bolts 4 in this embodiment are arranged staggered on both sides of the fixing plate 3. The fixing plate 3 can be used to fix the anchor bolts 4. Similarly, the anchor bolts 4 also play a role in fixing the fixing plate 3. The frame 2 is arranged on the fixing plate 3, and the rubber layer 1 is fixed on the frame 2 by steel wires or other means, so that the first concrete layer 7 can be connected to the rubber layer, playing a role in increasing the deformation, while the frame 2 can restrict the rubber layer 1 to prevent it from shifting during the concrete spraying process.

[0025] In the above embodiment, referring to Figure 3 As shown, a connecting bar 5 can be fixedly connected above the anchor bolt 4 by threading or welding. The connecting bar 5 extends upward into the second concrete layer and is fixed to the steel bars in the second concrete layer. Or the fixing plate 3 can also be extended to both sides for a certain length, and the connecting bar 5 is arranged on the extended section and extends into the second concrete layer.

[0026] The present invention further includes a construction method for the shotcrete reinforcement structure described above. This construction method includes setting up guide rails. To reduce construction steps, a combined structure of two fixing plates and the frame 2 at a predetermined distance can be selected and improved as the guide rails. Specifically, referring to Figure 3 As shown, the upper limit part 201 and the lower limit part 202 are provided at one end of the frame 2 away from the base layer. The upper limit part 201 and the lower limit part 202 include limit plates protruding from the inner surface of the frame 2. The upper limit part 201 and the lower limit part 202 on the upper part of the frame 2 form the guide rails. The slider 8 is arranged between the upper limit part 201 and the lower limit part. Wheels or balls can be provided on the slider 8. The height of the upper part of the frame 2 is higher than that of the first concrete layer 7. During the construction of the first concrete layer 7 in the tunnel, it is carried out in a bottom-up manner. An opening is provided below the guide rails for the slider 8 to enter between the upper limit part 201 and the lower limit part 202. The slider 8 is arranged on the frame 9. The frame 9 includes a bent part 901 and a cross bar 902. The bent part 901 bypasses the connecting bar 5, or the cross bar 902 is higher than the connecting bar 5. The cross bar 902 is connected to one end of the bent part 901 close to the surrounding rock. A baffle 903 is provided on the cross bar 902. Referring to Figure 4 As shown, a moving device is provided on the baffle 903. There are also tracks and strip-shaped holes 907 parallel to the tracks on the baffle 903. The moving device is connected to both sides of the strip-shaped holes 907 and moves along the strip-shaped holes 907. The moving device includes a moving plate 905. A nozzle 906 is provided on the moving plate 905. The spray gun is inserted into the nozzle 906. The position of the nozzle 906 is directly opposite to the strip-shaped holes 907 so that the concrete sprayed by the spray gun passes through the strip-shaped holes. The moving device can move along the tracks on the baffle 903. The above-mentioned cross bar 902 and the moving device can be respectively driven by a hydraulic system or a pneumatic system (not shown in the figure) to perform corresponding movements. When constructing the first concrete layer 7, start from the lower part of the tunnel wall first. The moving device and the spray gun move along the length direction of the tunnel for concrete spraying construction. After the lower-side concrete construction is completed, move the cross bar 902 to drive the frame 9 to move upward in the tunnel, and then move the spray gun again along the length direction of the tunnel for concrete spraying construction, repeating until the construction of the first concrete layer 7 in the corresponding area is completed. During the construction process, a concrete spraying machine is used. A hydraulic or pneumatic system can be provided on the concrete spraying machine and connected to the frame 9. Of course, the above-mentioned frame 9 can also be separately arranged on a wheeled conveying device, and the spray gun of the concrete spraying machine is inserted into the nozzle 906 of the baffle. The baffle 903 not only blocks the rebounding concrete, but also enables the spray gun to move along the baffle 903, so that the distance between the gun head of the spray gun and the tunnel wall is equal, and the pressure of the sprayed concrete is the same, with a more consistent compactness. On both sides of the guide rails, where it cannot be directly sprayed, it can be manually supplemented or constructed by adjusting the angle of the spray gun, such as in an inclined manner. After the shotcrete is completed, the frame 9 can also be separately moved to drive the side baffle to scrape the surface of the first concrete layer 7 back and forth.

[0027] In the above embodiments, with reference to Figure 3 as shown, a side baffle 904 is further provided on the frame 9. The edge position of the side baffle 904 is flush with the surface of the first concrete layer 7. When the frame 9 moves along the guide rail, the edge position of the side baffle 904 can scrape the surface of the first concrete layer 7 and make the thickness of the first concrete layer 7 uniform. In fact, a plurality of groups of anchor bolts 4 and fixing plates 3 are further provided on the bedrock 6 between the two combined structures (fixing plate 3 and frame 2) serving as the guide rail. Connecting bars 5 can also be provided on these fixing plates 3, and grooves matching the connecting bars 5 can be opened on the side baffle 904 for the connecting bars 5 to pass through.

[0028] In the above embodiments, the tunnel is generally constructed in segments, each segment being more than ten meters long. The deformation joints can generally be provided at each segment. The initial setting time of the rapid-hardening concrete is generally 1 hour or shorter. Therefore, the construction time can be reduced by dividing each segment into two or several segments. In another embodiment, the distance between the side baffle 904 and the surrounding rock of the tunnel wall is set to be adjustable. This adjustable method is a prior art, such as through a pneumatic or hydraulic system. At this time, a multi-layer spraying construction method can be adopted. After spraying a layer of concrete, the height of the side baffle 904 is adjusted, and concrete is sprayed again before the lower layer of concrete sets. After repeating several times, the first concrete layer 7 reaches the predetermined height. Adopting this construction method has better integrity and compactness.

[0029] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to form equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A construction method for sprayed concrete reinforcement structure, characterized in that: The shotcrete reinforcement structure comprises a first concrete layer and a second concrete layer which are constructed in sequence, wherein the first concrete layer is a quick-hardening concrete constructed on a base layer by a shotcrete method, a deformation band and a plurality of fixing plates are longitudinally arranged in the first concrete layer, the base layer is provided with an anchor rod, one end of the anchor rod is fixed on the fixing plate, the fixing plate is fixed in the first concrete layer, and after the first concrete layer is constructed, steel bars are arranged to construct the second concrete layer; The deformation band is a rubber layer, and the two sides of the rubber layer are fixed by a frame, and the frame is fixed on a fixing plate, and the fixing plates on both sides of the frame are provided with holes for fixing anchor rods; The fixing plate is fixed with connecting bars, which extend upward into the second concrete layer and are fixed to the steel bars in the second concrete layer; The construction method is specifically as follows: a guide rail parallel to the surface of the base layer is set, a slider of a frame moves on the guide rail, a baffle is set on the frame, the baffle is used to block rebounding concrete, a moving device is provided on the baffle, the moving device can move along the baffle, a concrete spray gun is set on the moving device and is used to spray concrete onto the base layer; when the first concrete layer is constructed, start from the lower part of the base layer, the moving device and the spray gun move along the length direction of the base layer to spray concrete, after the concrete construction on the lower side is completed, the frame moves to the upper part of the base layer, and the spray gun is moved along the length direction of the base layer again to spray concrete, and this is repeated until the first concrete layer construction of the corresponding area is completed.

2. A construction method for a shotcrete reinforcement structure according to claim 1, characterized in that: The frame is provided with an upper limit portion and a lower limit portion at one end away from the base layer. The upper limit portion and the lower limit portion include a limit plate protruding from the inner surface of the frame. The upper part of the frame forms the guide rail, and the slider is arranged between the upper limit portion and the lower limit portion.

3. A construction method for a shotcrete reinforcement structure according to claim 2, characterized in that: The frame comprises a bent portion, the bent portion bypasses the connecting ribs, the frame comprises a cross bar, the cross bar is connected to one end of the bent portion close to the base layer, and the baffle is arranged on the cross bar.

4. A construction method for a shotcrete reinforcement structure according to claim 1, 2 or 3, characterized in that: The baffle is provided with a strip hole, the moving device is connected to both sides of the strip hole and moves along the strip hole, the moving device includes a moving plate, a nozzle is provided on the moving plate, the spray gun is inserted into the nozzle, and the nozzle is located opposite to the strip hole so that the concrete sprayed by the spray gun passes through the strip hole.

5. A construction method for sprayed concrete reinforcement structure according to claim 4, characterized in that: The frame is also provided with a side baffle, the edge of which is at a predetermined distance from the base layer or flush with the surface of the first concrete layer. When the frame moves along the guide rail, the edge of the side baffle can scrape the surface of the first concrete layer and make the surface thickness of the first concrete layer uniform.

6. A construction method for a shotcrete reinforcement structure according to claim 5, characterized in that: The distance between the side baffle and the surrounding rock of the tunnel wall can be adjusted so that a multi-layer spraying construction method is adopted during the construction of the first concrete layer. After spraying a layer of concrete, the height of the side baffle is adjusted, and concrete is sprayed again before the lower layer of concrete solidifies. After repeating several times, the first concrete layer of a predetermined height is reached.

7. The construction method of a shotcrete reinforcement structure according to claim 1, characterized in that: The second concrete layer is constructed by concrete pouring or concrete spraying. The second concrete layer is concrete formed by mixing ordinary Portland cement, sand, crushed stone, water and admixtures.

Images