A support device and construction method for shallow buried biased large cross-section highway tunnel construction

Abstract

The present invention discloses a support device for shallow-buried biased large-section highway tunnel construction, comprising a telescopic steel frame, the upper and lower sides of the telescopic steel frame are both hinged with support plates, the support plates are detachably provided with multiple anchor rods at intervals along the length direction, an inclined positioning plate is provided on the telescopic steel frame, and multiple telescopic mechanisms are horizontally provided at intervals along the height direction inside the telescopic steel frame, one end of the telescopic mechanism is vertically connected to the left side inside the telescopic steel frame, and the other end passes through the positioning plate, and the movable end of the telescopic mechanism is hinged with an airbag unit mechanism. The present invention also discloses a construction method coordinated with the above-mentioned support device. By cooperating with the support device and the construction method, the consumption of temporary support concrete can be fully reduced under the premise of meeting the basic stability requirements of the highway tunnel construction process, thereby reducing the time of support application. Compared with the traditional CD / CRD method, its application in shallow-buried biased large-section tunnel construction has the significant advantages of fast construction period and low cost.

Description

Technical Field

[0001] The invention belongs to the field of highway tunnel engineering construction technology and construction process machinery, and specifically relates to a support device for shallow-buried biased large-section highway tunnel construction and a construction method thereof. Background Art

[0002] The construction of biased large-section tunnels places very high demands on the timeliness of temporary support due to engineering issues such as surrounding rock convergence and ground settlement requirements. At present, the engineering mainly adopts the sidewall pilot tunnel method represented by the CD method and the CRD method, which is based on the partial excavation strategy. Both methods require timely and large-scale temporary support, and too much temporary support will cause large-scale waste of materials, mainly shotcrete. Therefore, from the perspective of economy and resource recycling, it is necessary to propose a support scheme and supporting method that can effectively save the shotcrete required for the original temporary support. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a support device and a construction method for shallow buried biased large cross-section highway tunnel construction.

[0004] The first object of the present invention is to provide a support device for the construction of shallow-buried biased large-section highway tunnels, comprising a telescopic steel frame, wherein the upper and lower sides of the telescopic steel frame are hinged with support plates, the support plates are detachably provided with a plurality of anchor rods at intervals along their length direction, an inclined positioning plate is provided on the telescopic steel frame, and a plurality of telescopic mechanisms are horizontally arranged at intervals along the height direction inside the telescopic steel frame, one end of each telescopic mechanism is vertically connected to the left side inside the telescopic steel frame, and the other end passes through the positioning plate and extends to the outside of the positioning plate, and the movable end of the telescopic mechanism is hinged with an airbag unit mechanism.

[0005] Preferably, the telescopic steel frame includes a steel frame body, a plurality of first telescopic support members and a plurality of second telescopic support members, the steel frame body includes a first support member and a second support member vertically arranged on the top of the first support member, the plurality of first telescopic support members are arranged at intervals on the outside of the second support member along the width direction of the second support member, the plurality of second telescopic support members are arranged at intervals on the bottom of the first support member along the length direction of the first support member, and one end of each telescopic mechanism is fixedly connected to the inner side surface of the second support member.

[0006] Preferably, the positioning plate is a hollow plate, the top of the positioning plate is fixedly connected to the top of the inner side surface of the second support member, and the bottom is connected to an end of the upper surface of the first support member away from the second support member.

[0007] Preferably, the two supporting plates are respectively hinged to the top end of the second supporting member and an end of the first supporting member away from the second supporting member.

[0008] Preferably, the top and bottom of the inner side surface of the highest level airbag unit mechanism are respectively hinged to the top of the outer side surface of the positioning plate and the movable end of the highest level telescopic mechanism, and the top and bottom of the inner side surface of each of the remaining airbag unit mechanisms are respectively hinged to the movable ends of the corresponding two telescopic mechanisms in sequence along the height direction.

[0009] Preferably, each of the airbag unit mechanisms includes an airbag, an inflation and deflation valve and a load-bearing plate, wherein the inflation and deflation valve is arranged on the airbag, and the load-bearing plate is fixedly connected to the outer side surface of the airbag through a plurality of connecting parts, and the top of the side surface of the load-bearing plate opposite to the connecting part is hinged to the movable end of the telescopic mechanism or the top of the outer side surface of the positioning plate, and the bottom is hinged to the movable end of the telescopic mechanism below.

[0010] Preferably, a foam hanging plate is connected to the outer side surface of the airbag opposite to the connecting piece through a snap buckle, the movable ends of the first telescopic support piece and the second telescopic support piece are both provided with foot pads, and the telescopic mechanism, the first telescopic support piece and the second telescopic support piece are all hydraulic telescopic rods.

[0011] A second object of the present invention is to provide a construction method for shallow buried biased large cross-section highway tunnel construction, comprising the following steps:

[0012] S1. Excavation of small pilot tunnel, excavation distance is 5~15m:

[0013] S2. Excavate the side of the mountain away from the expansion side:

[0014] S3, taking anchor spraying operation to permanently support the part of the mountain far away from the expansion side excavated in step S2;

[0015] S4. Mark the required driving points and directions of the anchor rods on the expansion side;

[0016] S5, placing the support device on the expansion excavation side, and setting the airbag in the support device between the primary support lining and the bearing plate, inflating it to be in a squeezed state, and driving multiple anchor rods into the surrounding rock on the expansion excavation side through the support plate according to the driving points and directions marked in step S4, so that the support plate and the anchor rods jointly support the surrounding rock on the expansion excavation side, and adjusting the directions of the multiple bearing plates and the distances between the bearing plates and the surrounding rock by using multiple telescopic mechanisms respectively, so that the airbag fits the surrounding rock on the expansion excavation side, and further supports the surrounding rock on the expansion excavation side by using the airbag and the bearing plate, and starts the excavation of part I;

[0017] S6. After completing the excavation of part I, continue to excavate small pilot holes in units of 15 m, deflate the airbags in step S5, and remove the anchor rods;

[0018] S7, repeat steps S2-S6 to excavate parts II and III;

[0019] S8, after completing the excavation of part II and part III, continue to repeat steps S2-S6 to excavate part IV and part V, and part IV and part V are excavated with steps staggered by 1 to 1.5 m;

[0020] S9. After the excavation of Section V is completed, reinforcement support is carried out at a distance of 2m from the tunnel face of Section V;

[0021] S10. After the reinforcement support in step S9 is completed, a steel mesh is laid on the reinforcement support, and concrete with a thickness of 5-10 cm is evenly sprayed for further reinforcement support.

[0022] Preferably, during the excavation process of parts I, II and III, parts I, II and III are kept offset from the upper part by 15m.

[0023] Preferably, the steel mesh is a φ6@15*15 steel mesh.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention uses the airbags in the support device to temporarily fill the space between the steel frame and the excavated surrounding rock. The airbags are flexible and easy to inflate and deflate to achieve a flexible and close contact with the surrounding rock, so that the steel frame can fully play the role of bearing and supporting the exposed surrounding rock.

[0026] (2) The present invention can provide joint support for the exposed surrounding rock through the support plates, anchor rods, load-bearing plates and airbags in the support device, and fully form an independent and closed force-bearing system, thereby improving the support stability during the tunnel construction process;

[0027] (3) The present invention uses a supporting device in conjunction with the construction method provided by the present invention, which can fully reduce the consumption of temporary support concrete while meeting the basic stability requirements of the highway tunnel construction process, thereby reducing the support construction time. Compared with the traditional CD / CRD method, it has the significant advantages of fast construction period and low cost when applied to shallow buried biased large-section tunnel construction, and is more suitable for tunnel construction engineering scenes with a high degree of mechanization;

[0028] (4) The present invention can better achieve a balance between stability, economy and timeliness of support by maintaining an excavation method in which parts I, II and III are offset by 15m from the upper part during the excavation of parts I, II and III. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a support device for shallow-buried, biased, large-section highway tunnel construction provided in Example 1 of the present invention;

[0030] Figure 2 A schematic diagram of the structure of a support device for shallow-buried, biased, large-section highway tunnel construction in a construction state provided by Embodiment 1 of the present invention;

[0031] Figure 3 A left view of a support device for shallow-buried biased large-section highway tunnel construction provided by Example 1 of the present invention;

[0032] Figure 4 A right side view of a support device for shallow buried biased large cross-section highway tunnel construction provided by Example 1 of the present invention;

[0033] Figure 5 It is a structural schematic diagram of the airbag unit mechanism in Embodiment 1 of the present invention;

[0034] Figure 6 A schematic diagram of excavation of parts I, II, III, IV and V in the construction method provided in Example 1 of the present invention;

[0035] Figure 7 This is a schematic diagram of the connection structure between the air bag and the foam hanging board in Example 2 of the present invention;

[0036] In the figure: 1. telescopic mechanism; 2. positioning plate; 3. foot pad; 4. connecting piece; 5. airbag unit mechanism; 501. airbag; 502. charging and discharging valve; 503. load-bearing plate; 6. anchor rod; 7. supporting plate; 8. telescopic steel frame; 801. steel frame body; 802. first telescopic support member; 803. second telescopic support member; 804. first support member; 805. second support member; 9. buckle; 10. foam hanging plate. DETAILED DESCRIPTION

[0037] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0038] Example 1

[0039] like Figures 1 to 5As shown, the embodiment of the present invention provides a support device for shallow buried biased large cross-section highway tunnel construction, specifically comprising a telescopic steel frame 8, the upper and lower sides of the telescopic steel frame 8 are hinged with support plates 7, the support plates 7 are detachably provided with multiple anchor rods 6 at intervals along the length direction thereof, the telescopic steel frame 8 is provided with an inclined positioning plate 2, the interior of the telescopic steel frame 8 is horizontally provided with multiple telescopic mechanisms 1 at intervals along the height direction, one end of each telescopic mechanism 1 is vertically connected to the left side of the interior of the telescopic steel frame 8, the other end passes through the positioning plate 2 and extends to the outside of the positioning plate 2, and the movable end of the telescopic mechanism 1 is hinged with an airbag unit mechanism 5. The arrangement of the telescopic mechanism 1 is determined by the number and layout of the airbag unit mechanism 5.

[0040] The telescopic steel frame 8 comprises a steel frame body 801, a plurality of first telescopic supports 802 and a plurality of second telescopic supports 803. The steel frame body 801 comprises a first support 804 and a second support 805 vertically arranged on the top of the first support 804. The plurality of first telescopic supports 802 are arranged at intervals on the outside of the second support 805 along the width direction of the second support 805. The plurality of second telescopic supports 803 are arranged at intervals on the bottom of the first support 804 along the length direction of the first support. One end of each telescopic mechanism 1 is fixedly connected to the inner side of the second support 805. Through the design of the first telescopic supports 802 and the second telescopic supports 803, when the support device enters the joint anchor support state, the first telescopic supports 802 and the second telescopic supports 803 can be retracted to allow other construction machinery to enter and exit the workspace.

[0041] The positioning plate 2 is a hollow plate, the top of the positioning plate 2 is fixedly connected to the top of the inner side of the second support member 805, and the bottom is connected to the end of the upper surface of the first support member 804 away from the second support member 805. In the actual design, the positioning plate 2 is parallel to the initial position of the load-bearing plate 503. The design of the positioning plate 2 can facilitate the installation of the airbag unit mechanism 5, timely adjust the facing angle of the airbag 501, limit the telescopic mechanism 1, and meet the design function requirements of direct load bearing under necessary working conditions.

[0042] The two supporting plates 7 are respectively hinged to the top end of the second supporting member 805 and an end of the first supporting member 804 away from the second supporting member 805 .

[0043] The top and bottom of the inner side surface of the highest level airbag unit mechanism 5 are respectively hinged to the top of the outer side surface of the positioning plate 2 and the movable end of the highest level telescopic mechanism 1, and the top and bottom of the inner side surface of each of the remaining airbag unit mechanisms 5 are respectively hinged to the movable ends of the corresponding two telescopic mechanisms 1 in sequence along the height direction.

[0044] Each of the airbag unit mechanisms 5 comprises an airbag 501, an air filling and discharging valve 502 and a bearing plate 503. The air filling and discharging valve 502 is arranged on the airbag 501. The bearing plate 503 is fixedly connected to the outer side of the airbag 501 through a plurality of connecting members 4. The top of the side opposite to the connecting member 4 on the bearing plate 503 is hinged to the movable end of the telescopic mechanism 1 or the top of the outer side of the positioning plate 2, and the bottom is hinged to the movable end of the telescopic mechanism 1 below. The connecting member 4 can be a bolt. The airbag 501 is used to temporarily fill the space between the telescopic steel frame 8 and the excavated surrounding rock. With the help of the flexibility of the airbag 501 and the convenience of inflation and deflation, the airbag 501 can be used to achieve a flexible and close contact with the surrounding rock, so that the telescopic steel frame can fully play the role of bearing and supporting the excavated exposed surrounding rock.

[0045] The movable ends of the first telescopic support member 802 and the second telescopic support member 803 are provided with foot pads 3, and the telescopic mechanism 1, the first telescopic support member 802 and the second telescopic support member 803 are all hydraulic telescopic rods. Through the design of the foot pads 3, the contact area between the first telescopic support member 802 and the second telescopic support member 803 and the surrounding rock can be increased respectively, so that the rock and soil can be better contacted and supported, and direct and large contact stress can be avoided.

[0046] like Figure 6 As shown, the embodiment of the present invention also provides a construction method for shallow buried biased large cross-section highway tunnel construction, which specifically includes the following steps:

[0047] S1. Excavation of small pilot tunnel, excavation distance is 5~15m:

[0048] S2. Excavate the side of the mountain away from the expansion side:

[0049] S3, taking anchor spraying operation to permanently support the part of the mountain far away from the expansion side excavated in step S2;

[0050] S4, marking the required driving point and direction of the anchor rod 6 on the expansion side;

[0051] S5, placing the support device on the expansion excavation side, and setting the airbag 501 in the support device between the primary support lining and the bearing plate 503, inflating it to be in a squeezed state, and driving multiple anchor rods 6 into the surrounding rock on the expansion excavation side through the support plate 7 according to the driving point and direction marked in step S4, so that the support plate 7 and the anchor rods 6 jointly support the surrounding rock on the expansion excavation side, and adjusting the directions of the multiple bearing plates 503 and the distances between the bearing plates 503 and the surrounding rock by the multiple telescopic mechanisms 1 respectively, so that the airbag 501 fits the surrounding rock on the expansion excavation side, and further supports the surrounding rock on the expansion excavation side through the airbag 501 and the bearing plate 503, and starts the excavation of part I;

[0052] S6. After completing the excavation of part I, continue to excavate the small pilot hole forward in units of 15 m, deflate the airbag 501 in step S5, and remove the anchor rod;

[0053] S7, repeating steps S2-S6 to excavate parts II and III; during the excavation of parts I, II and III, keep parts I, II and III offset from the upper part by 15m;

[0054] S8, after completing the excavation of part II and part III, continue to repeat steps S2-S6 to excavate part IV and part V, and part IV and part V are excavated with steps staggered by 1 to 1.5 m;

[0055] S9. After the excavation of Section V is completed, reinforcement support is carried out at a distance of 2m from the tunnel face of Section V;

[0056] S10. After the reinforcement support in step S9 is completed, a steel mesh is laid on the reinforcement support. The steel mesh uses a φ6@15*15 steel mesh, and 5-10cm thick concrete is evenly sprayed on the steel mesh for further reinforcement support.

[0057] Example 2

[0058] The support device and construction method provided in the embodiment of the present invention are the same as those in the embodiment 1, except that the outer surface of the airbag 501 in the support device of the embodiment 1 of the present invention opposite to the connecting member is connected with a foam hanging plate 10 through a buckle 9. Figure 7 During the excavation process, if there are sharp rocks in the exposed rock mass, the explosion-proof design of the foam hanging plate 10 can prevent the sharp rocks from scratching and puncturing the airbag 501, thereby extending the service life of the airbag 501.

[0059] When the support device in the embodiment of the present invention is actually used, in a specific working step, the support device is moved to the required support position, and then the surrounding and bottom supporting rock and soil bodies are effectively supported by extending the first telescopic support member 802 and the second telescopic support member 803. Then, the detachable anchor rod 6 is installed on the upper and lower side support plates 7 of the telescopic steel frame 8, and the anchor rod 6 is driven into the surrounding rock on the expansion side through the support plate 7 according to the marked driving point and direction, so that the support plate 7 and the anchor rod 6 jointly support the surrounding rock on the expansion side, and then the first telescopic support member 802 and the second telescopic support member 803 are retracted. The load-bearing plate 503 is in place, and the anchor rod 6 is checked; then the air bag 501 is integrated into the compressed air supply system to be inflated, and is brought close to the supporting surrounding rock, and the penetration of the telescopic mechanism 1 is adjusted to be in close contact with the surrounding rock; if there are sharp rocks in the exposed rock mass during excavation, it is necessary to pre-install a foam hanging plate on the side of the air bag 501 facing the rock mass, and then excavation is carried out; when it is necessary to carry out the next area excavation step, the compressed air in the air bag 501 is released and the first telescopic support member 802 and the second telescopic support member 803 are stretched to form an effective support, the detachable anchor rod 8 is removed and the connection with the support plate 7 is removed, and then the anchor rod 6 is removed, and finally the telescopic steel frame 8 is transferred.

[0060] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A support device for shallow buried biased large cross-section highway tunnel construction, characterized in that: The invention comprises a telescopic steel frame (8), wherein the upper and lower sides of the telescopic steel frame (8) are both hingedly connected to a supporting plate (7), and the supporting plate (7) is detachably provided with a plurality of anchor rods (6) at intervals along its length direction; an inclined positioning plate (2) is provided on the telescopic steel frame (8), and a plurality of telescopic mechanisms (1) are horizontally arranged at intervals along the height direction inside the telescopic steel frame (8), one end of each telescopic mechanism (1) is vertically connected to the left side inside the telescopic steel frame (8), and the other end passes through the positioning plate (2) and extends to the outside of the positioning plate (2); and the movable end of the telescopic mechanism (1) is hingedly connected to an airbag unit mechanism (5).

2. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 1 is characterized in that: The telescopic steel frame (8) comprises a steel frame body (801), a plurality of first telescopic support members (802) and a plurality of second telescopic support members (803); the steel frame body (801) comprises a first support member (804) and a second support member (805) vertically arranged on the top of the first support member (804); the plurality of first telescopic support members (802) are arranged at intervals on the outside of the second support member (805) along the width direction of the second support member (805); the plurality of second telescopic support members (803) are arranged at intervals on the bottom of the first support member (804) along the length direction of the first support member; and one end of each telescopic mechanism (1) is fixedly connected to the inner side surface of the second support member (805).

3. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 2 is characterized in that: The positioning plate (2) is a hollow plate, the top of the positioning plate (2) is fixedly connected to the top of the inner side of the second support member (805), and the bottom is connected to an end of the upper surface of the first support member (804) away from the second support member (805).

4. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 2 is characterized in that: The two support plates (7) are respectively hinged to the top end of the second support member (805) and an end of the first support member (804) away from the second support member (805).

5. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 1 is characterized in that: The top and bottom of the inner side surface of the highest level airbag unit mechanism (5) are respectively hinged to the top of the outer side surface of the positioning plate (2) and the movable end of the highest level telescopic mechanism (1), and the top and bottom of the inner side surface of each of the remaining airbag unit mechanisms (5) are respectively hinged to the movable ends of the corresponding two telescopic mechanisms (1) in sequence along the height direction.

6. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 2 is characterized in that: Each of the airbag unit mechanisms (5) comprises an airbag (501), an air inflation and deflation valve (502) and a load-bearing plate (503); the air inflation and deflation valve (502) is arranged on the airbag (501); the load-bearing plate (503) is fixedly connected to the outer side surface of the airbag (501) via a plurality of connecting members (4); the top of the side surface of the load-bearing plate (503) opposite to the connecting member (4) is hinged to the movable end of the telescopic mechanism (1) or the top of the outer side surface of the positioning plate (2); and the bottom is hinged to the movable end of the telescopic mechanism (1) below.

7. The support device for shallow buried biased large cross-section highway tunnel construction according to claim 6 is characterized in that: A foam hanging plate (10) is connected to the outer side surface of the airbag (501) opposite to the connecting member (4) via a buckle (9); the movable ends of the first telescopic support member (802) and the second telescopic support member (803) are both provided with foot pads (3); and the telescopic mechanism (1), the first telescopic support member (802) and the second telescopic support member (803) are all hydraulic telescopic rods.

8. A construction method for shallow buried biased large cross-section highway tunnel construction, implemented by using the support device according to claim 6, characterized in that: The following steps are involved: S1. Excavation of small pilot tunnel, excavation distance is 5~15m: S2. Excavate the side of the mountain away from the expansion side: S3, taking anchor spraying operation to permanently support the part of the mountain far away from the expansion side excavated in step S2; S4, marking the required driving points and directions of the anchor rods (6) on the expansion side; S5, placing the support device on the expansion side, and setting the airbag (501) in the support device between the primary support lining and the bearing plate (503), inflating it to put it in a squeezed state, and driving a plurality of anchor rods (6) into the surrounding rock on the expansion side through the support plate (7) according to the driving points and directions marked in step S4, so that the support plate (7) and the anchor rods (6) jointly support the surrounding rock on the expansion side, and adjusting the directions of the plurality of bearing plates (503) and the distances between the bearing plates (503) and the surrounding rock by using a plurality of telescopic mechanisms (1) respectively, so that the airbag (501) fits the surrounding rock on the expansion side, and further supports the surrounding rock on the expansion side through the airbag (501) and the bearing plate (503), and starts excavation of part I; S6. After completing the excavation of part I, continue to excavate the small pilot hole forward in units of 15 m, deflate the airbag (501) in step S5, and remove the anchor rod; S7, repeat steps S2-S6 to excavate parts II and III; S8, after completing the excavation of part II and part III, continue to repeat steps S2-S6 to excavate part IV and part V, and part IV and part V are excavated with steps staggered by 1 to 1.5 m; S9. After the excavation of Section V is completed, reinforcement support is carried out at a distance of 2m from the tunnel face of Section V; S10. After the reinforcement support in step S9 is completed, a steel mesh is laid on the reinforcement support, and concrete with a thickness of 5-10 cm is evenly sprayed for further reinforcement support.

9. The construction method for shallow-buried biased large-section highway tunnel construction according to claim 8, characterized in that: During the excavation of parts I, II and III, parts I, II and III are kept offset by 15m from the upper part.

10. The construction method for shallow-buried biased large-section highway tunnel construction according to claim 8, characterized in that: The steel bar mesh is a φ6@15*15 steel bar mesh.

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