Temporary working platform for high and steep slope tunnel portal

Abstract

The utility model discloses a temporary working platform for a high and steep slope tunnel portal, which comprises a supporting and retaining structure serving as a platform foundation and comprising a supporting pile arranged on a slope of the tunnel portal, and a soil and stone backfill body arranged between the supporting pile and the slope; the laminated slab comprises a concrete layer located on the upper layer and a steel plate layer located on the lower layer, and the laminated slab is connected with the supporting and retaining structure and the undisturbed soil hardening platform; the jacking structure comprises a grouting bag arranged between the top of the soil and stone backfill body and the bottom surface of the laminated slab and is used for grouting when the soil and stone backfill body settles so as to jack the laminated slab; the anchor rod cable-stayed structure comprises a stay cable, a protective anchor rod arranged on a side slope and a cable bent tower support arranged on a ventilator support of a tunnel, and the stay cable penetrates through the top of the cable bent tower support and is connected with the laminated slab and the protective anchor rod.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel engineering, in particular to a temporary working platform for a tunnel opening with a high and steep slope. Background Art

[0002] Tunnel construction is commonly involved in highway engineering, railway engineering, water conservancy and hydropower engineering, and mining engineering. In mountainous engineering, tunnel entrances are often located in valley gullies, with steep terrain and high and steep slopes with large natural slopes. For this type of tunnel construction, common methods of creating construction platforms include earth and stone backfilling and steel platforms.

[0003] The soil and rock backfill platform has good stability and is easy to construct. The commonly used tunnel entrance backfill platform is suitable for tunnels with relatively gentle terrain or a low vertical height from the valley bottom. The backfill slope foot is unprotected or protected by a low retaining wall. For example, Patent No.: 202220356347X discloses a steep slope operation platform structure for the tunnel entrance, which is supported by an inclined reinforced retaining wall + steel pipe pile foundation + expanded connecting beam + a Chinese-shaped steel bar bundle, and a reinforced concrete stress dispersion layer and a reinforced concrete top layer are set to increase the anti-overturning capacity of the retaining wall to adapt to the construction of complex steep slope tunnel entrance operation platforms. However, the conventional soil and rock backfill platform method is only suitable for the construction of tunnel entrance operation platforms with gentle terrain and small backfill height. When the terrain of the tunnel entrance is more complex or the slope is large and the vertical height of the tunnel entrance is high, the backfill height will also be higher, forming a high fill, and the stability of the platform will be reduced. If slope backfilling is adopted, the amount of platform backfilling engineering will increase significantly, increasing the difficulty of construction. If retaining walls are used, the volume of the retaining walls in the high-fill area will also be correspondingly larger, the construction difficulty will be high, and the construction period will be long, which will affect the construction progress of the main project. In addition, the amount of concrete required for the retaining wall is large, which increases the construction cost.

[0004] At present, common steel platforms are built by setting up Bailey frames or other steel structures on the top of pile foundation columns. For example, the tunnel entrance construction platform for confined spaces disclosed in Patent No.: 202020616097X has multiple columns on the steep slopes, parallel main beams above the columns, Bailey frames above the main beams, and a tunnel entrance construction platform with a combined steel panel above the Bailey frames. The platform has a simple structure and can adapt to more complex terrain; the columns, Bailey frames, and steel panels can be reused, which reduces the construction cost. However, the terrain of the steep slopes is complex, and the construction of the steel platform is more difficult, and the pile foundation or column cantilever of the steel platform is long and the stability is poor. The steel platform is a steel structure with high material costs, especially when the leasing model is adopted and the construction period is delayed.

[0005] In summary, the existing technology has at least the following problems: the earth-rock backfill platform is suitable for the opening platform with gentle terrain and low height, but is no longer applicable when the terrain is complex; the common method of building a construction platform with a retaining wall basically has the problems of great construction difficulty, slow construction and high cost; the earth-rock backfill platform is bound to have the problem of fill settlement, which causes the upper hardened layer to crack and collapse, affecting the construction; the steel platform generally has the problems of difficult construction and high cost. Utility Model Content

[0006] The utility model provides a temporary working platform for a tunnel opening with a high steep slope, so as to solve the technical problems in the prior art of difficult construction of earth-rock backfill platforms in complex terrain, fill settlement, and difficult and high-cost construction of steel platforms.

[0007] According to one aspect of the utility model, a temporary working platform for a tunnel entrance with a high and steep slope is provided, comprising:

[0008] The retaining structure, as the platform foundation, comprises support piles for setting at the side slope of the tunnel opening, and a soil and rock backfill body is set between the support piles and the side slope;

[0009] The composite slab includes a concrete layer at the upper layer and a steel plate layer at the lower layer, and the composite slab is respectively connected to the retaining structure and the original soil hardening platform;

[0010] The supporting structure includes a grouting bag arranged between the top of the earth-rock backfill body and the bottom surface of the composite plate, and is used for grouting to support the composite plate when the earth-rock backfill body settles;

[0011] The anchor rod inclined structure comprises an inclined cable, a protective anchor rod arranged on a slope and a cable tower support of a ventilator support arranged on a tunnel. The inclined cable passes through the top of the cable tower support and is respectively connected to the composite plate and the protective anchor rod.

[0012] As a further improvement of the above technical solution, an anti-slip pile structure is provided on the slope at a preset angle within the range of the earth-rock backfill body.

[0013] As a further improvement of the above technical solution, the composite plate is hinged to the original soil hardening platform through a pin arranged along the longitudinal direction, or the end of the composite plate is hinged to the original soil hardening platform through a force transmission anchor bolt and an elastic filler.

[0014] As a further improvement of the above technical solution, temporary wet joints and / or connecting steel plates are provided between adjacent composite plates.

[0015] As a further improvement of the above technical solution, a basic support layer is provided at the bottom of the ventilation bracket.

[0016] As a further improvement of the above technical solution, a static level is installed on the tower support.

[0017] As a further improvement of the above technical solution, a stress detection device is provided on the inclined cable.

[0018] As a further improvement of the above technical solution, the composite plate is cantilevered at one end away from the tunnel entrance, and a supporting structure is provided between the cantilevered end of the composite plate and the retaining structure.

[0019] As a further improvement of the above technical solution, a construction access road is provided below the cantilevered end of the composite slab.

[0020] As a further improvement of the above technical solution, a pulley block for cooperating with the inclined cable is arranged on the cable tower support.

[0021] The utility model has the following beneficial effects:

[0022] The work platform uses easy-to-construct support piles as the retaining structure for backfill soil and as the lower support for the temporary work platform, replacing large-volume concrete structures such as retaining walls. Backfill soil and stone are used as the platform foundation behind the retaining structure, effectively ensuring the stability of the platform while reducing the amount of backfill soil and stone, greatly reducing the construction difficulty and construction cost, and effectively solving the problem that the temporary working platform of a tunnel with a high steep slope is narrow and not conducive to construction, and the problem that the filling project of the earth platform at the tunnel entrance is large and the construction cost is high; the composite plate adopts an assembled composite plate of concrete and steel plates, which has the advantages of both steel plates and concrete, and the assembled components are easy to construct and can be recycled repeatedly, solving the problem that the temporary working platform on a high steep slope has a large hardening area and needs to be rebuilt after use. The material waste and high construction cost caused by demolition are solved; an anchor rod inclined pull mechanism is set up, the protective anchor rod of the tunnel entrance slope is used as the ground anchor, and the tunnel entrance ventilator bracket is used as the cable tower to further set the cable tower bracket, and the steel wire rope inclined cable is used to provide inclined pull force to the composite plate panel, thereby reducing the disturbance of the force on the upper part of the composite plate to the earth-rock fill foundation, and slowing down the settlement rate of the earth-rock backfill body; by setting up a top support structure, when the earth-rock backfill body settles and becomes empty under the action of gravity, the grouting bag is located in the settlement and empty space, and the grouting bag is grouted and bulged to form a top support to lift the upper composite plate, thereby ensuring the horizontal stability of the platform panel, and solving the problem of hardening and cracking of the platform and even collapse of the platform caused by the settlement of the earth platform at the tunnel entrance with a high steep slope.

[0023] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the preferred embodiment of the utility model Figure 1 ;

[0026] Figure 2 yes Figure 1 A magnified image of point A;

[0027] Figure 3 It is a structural schematic diagram of the cantilevered arrangement of the composite plate in one embodiment of the utility model;

[0028] Figure 4 This is a schematic diagram of the structure of the preferred embodiment of the utility model Figure 2 ;

[0029] Figure 5 It is a schematic diagram of the composite plate structure of a preferred embodiment of the utility model;

[0030] Figure 6 This is a schematic diagram of the connecting hinge structure of an embodiment of the utility model Figure 1 ;

[0031] Figure 7 This is a schematic diagram of the connecting hinge structure of an embodiment of the utility model Figure 2 ;

[0032] Figure 8 This is a schematic diagram of the connecting hinge structure of another embodiment of the utility model Figure 1 ;

[0033] Fig. 9 This is a schematic diagram of the connecting hinge structure of another embodiment of the utility model Figure 2 ;

[0034] Fig.10 This is a schematic diagram of the connection structure of adjacent superimposed plates in one embodiment of the utility model;

[0035] Fig.11 It is a schematic diagram of the connection structure of adjacent superimposed plates in another embodiment of the utility model;

[0036] Fig.12 This is a schematic diagram of a backfill anti-slip structure of an embodiment of the utility model;

[0037] Fig.13 It is a schematic diagram of the backfill anti-slip structure of another embodiment of the utility model.

[0038] Legend:

[0039] 1. Composite plate 101, cantilever end 102, steel plate layer 103, rivet 104, concrete layer 2, retaining structure 3, jacking structure 4, inclined cable 5, fan bracket 6, connecting hinge 7, stress detection device 8, earth and rock backfill 9, tunnel opening 10, slope 11, protective anchor rod 12, foundation support layer 13, settlement observation pile 14, anti-slip pile 15, original ground line 16, ventilation duct 17, support structure 18, construction access road. DETAILED DESCRIPTION

[0040] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. However, the present invention can be implemented in a variety of different ways as defined and covered below.

[0041] Figure 1 This is a schematic diagram of the structure of the preferred embodiment of the utility model Figure 1 ; Figure 2 yes Figure 1 A magnified image of point A; Figure 3 It is a structural schematic diagram of the cantilevered arrangement of the composite plate in one embodiment of the utility model; Figure 4 This is a schematic diagram of the structure of the preferred embodiment of the utility model Figure 2 ; Figure 5 It is a schematic diagram of the composite plate structure of a preferred embodiment of the utility model; Figure 6 This is a schematic diagram of the connecting hinge structure of an embodiment of the utility model Figure 1 ; Figure 7 This is a schematic diagram of the connecting hinge structure of an embodiment of the utility model Figure 2 ; Figure 8 This is a schematic diagram of the connecting hinge structure of another embodiment of the utility model Figure 1 ; Fig. 9 This is a schematic diagram of the connecting hinge structure of another embodiment of the utility model Figure 2 ; Fig.10 This is a schematic diagram of the connection structure of adjacent superimposed plates in one embodiment of the utility model; Fig.11 It is a schematic diagram of the connection structure of adjacent superimposed plates in another embodiment of the utility model; Fig.12 This is a schematic diagram of a backfill anti-slip structure of an embodiment of the utility model; Fig.13 It is a schematic diagram of the backfill anti-slip structure of another embodiment of the utility model.

[0042] like Figure 1-Figure 13 As shown, the temporary working platform for the tunnel opening 9 on the steep slope 10 of this embodiment includes:

[0043] The retaining structure 2, as a platform foundation, includes support piles for setting up the slope 10 of the tunnel opening 9, and a soil and rock backfill body 8 is set between the support piles and the slope 10;

[0044] The composite plate 1 includes a concrete layer 104 at the upper layer and a steel plate layer 102 at the lower layer. The composite plate 1 is connected to the retaining structure 2 and the original soil hardening platform respectively.

[0045] The supporting structure 3 includes a grouting bag arranged between the top of the soil-rock backfill body 8 and the bottom surface of the composite board 1, and is used for grouting to support the composite board 1 when the soil-rock backfill body 8 settles;

[0046] The anchor rod inclined structure comprises an inclined cable 4, a protective anchor rod 11 arranged on the slope 10 and a tower support of a ventilator support 5 arranged in the tunnel. The inclined cable 4 is passed through the top of the tower support and is respectively connected to the composite plate 1 and the protective anchor rod 11.

[0047] Among them, the supporting piles include pine piles and / or steel pipe piles and / or shoulder walls set on the slope 10 for support, which are selectively set according to the construction environment and actual needs; the slope 10 of the tunnel opening 9 will be sprayed with concrete or trial anchors to support the slope 10 during construction. The anchor rod inclined pull mechanism of this embodiment uses the protective anchor rod 11 of the slope 10 as a ground anchor; the protective anchor rod 11 adopts small or micro penetration piles, which are convenient to construct and less restricted by the terrain, giving full play to the advantages of low cost of temporary structures; stabilizing the original soil in front of the tunnel opening 9 and the hardened concrete slab above it are realized by referring to the existing technology; the fan bracket 5 is a bracket used for erecting the ventilation duct 16 at the tunnel opening 9 in the prior art;

[0048] It can be understood that the present working platform replaces large-volume concrete structures such as retaining walls by using support piles that are easy to construct as the retaining structure 2 for backfill soil and as the lower support for the temporary working platform. Backfill soil and stone are used as the platform foundation behind the retaining structure 2, which effectively ensures the stability of the platform while reducing the amount of backfill soil and stone, greatly reducing the construction difficulty and construction cost, and effectively solving the problem that the temporary working platform of the tunnel with high steep slope 10 is narrow and not conducive to construction, and the problem that the earth platform at the tunnel entrance 9 has a large amount of filling work and high construction cost; the composite plate 1 adopts an assembled composite plate 1 of concrete and steel plates, which has the advantages of both steel plates and concrete, and the assembled components are easy to construct and can be recycled repeatedly, solving the problem that the temporary working platform of the high steep slope 10 has a large hardened area and is difficult to repair after use. The material waste and construction cost caused by the demolition are high; an anchor rod inclined-stayed mechanism is set up, and the protective anchor rod 11 of the tunnel entrance slope 10 is used as a ground anchor, and the tunnel entrance ventilator bracket 5 is used as a cable tower to further set up a cable tower bracket, and the steel wire rope inclined cable is used to provide an inclined tension force to the composite plate 1 panel, thereby reducing the disturbance of the force on the upper part of the composite plate 1 to the earth-rock filling foundation, and slowing down the settlement speed of the earth-rock backfill body 8; by setting a top support structure 3, when the earth-rock backfill body 8 settles and becomes empty under the action of gravity, the grouting bag is located in the settlement and emptying, and the grouting bag is grouted and bulged to form a top support to lift the upper composite plate 1, thereby ensuring the horizontal stability of the platform panel, and solving the problem that the high steep slope 10 tunnel entrance 9 soil platform filling settlement leads to platform hardening and cracking, and even platform collapse.

[0049] In this embodiment, the grouting bag is a hollow bag body, which is closely attached to the composite board 1 and connected with a cementing material, and a grouting pipeline is reserved. When the soil-rock backfill body 8 settles and becomes empty due to gravity, the grouting bag is located in the settled empty space. At this time, grouting can be injected into the bag body. After the grouting, the bag body bulges to form a top support to lift the upper composite board 1, thereby ensuring the horizontal stability of the platform panel.

[0050] Furthermore, a soft material such as a rubber pad or a cloth pad is placed above the soil and rock backfill body 8 as an anti-puncture layer to prevent sharp stones or branches below from puncturing the grouting bag.

[0051] In some embodiments, reference Fig.12 , meet the conditions of the construction environment, refer to the existing technology to excavate steps and backfill at the original ground line 15 to increase the stability of the backfill interface; in this embodiment, refer to Fig.13 On the slope 10, an anti-slip pile 14 structure is arranged at a preset angle within the soil and rock backfill body 8. On the ground of the original slope 10, an anti-slip structure such as pine piles is driven into the ground at a vertical angle to replace the conventional steps as the junction connection, so as to solve the problem that the steps are difficult to excavate due to the complex terrain;

[0052] In this embodiment, the composite plate 1 is a concrete-steel composite plate 1, the upper layer is high-strength concrete with a thickness h1 of 10 to 20 cm, and the lower layer is a steel plate with a thickness h2 of 1 to 3 cm; rivets 103 are welded on the steel plate as shear nails to strengthen the connection between the upper and lower layers of the composite plate 1;

[0053] In this embodiment, the composite plate 1 is hinged to the original soil hardening platform, and the composite plate 1 is connected to the hardened concrete plate above the stable original soil of the cave entrance by means of a hinge, so as to release the tensile stress and tensile cracks caused by the bending moment at the connection part between the composite plate 1 and the original soil hardening plate part when the soil below the composite plate 1 settles due to the bottom of the plate being emptied;

[0054] In one embodiment, reference Figure 6 and Figure 7 The connection hinge 6 of the two is that the composite plate 1 is hinged to the original soil hardening platform through a pin arranged along the longitudinal direction to allow large angle deformation of the connection;

[0055] In one embodiment, it can also be, with reference to Figure 8 and Fig. 9 The end of the composite plate 1 is hinged to the original soil hardening platform through force-transmitting anchor bolts and elastic fillers. The selection principle of the two hinge modes can be estimated according to the predicted settlement of the backfill height and the width of the composite plate 1. The hinge rotation angle is finally determined according to the maximum rotation angle.

[0056] The composite plate 1 and the retaining structure 2 should be connected by a fixed connection that is easy to break and does not cause damage, so as to facilitate later recycling and turnover; in this embodiment, a larger hole is reserved on the composite plate 1, and an elastic filler structure can be reserved on the top of the retaining structure 2 to consolidate the composite plate 1; while the retaining structure 2 supports the composite plate 1, the composite plate 1 can apply a horizontal tension to the retaining structure 2 through the anchor structure to improve the stability of the retaining structure 2;

[0057] In this embodiment, temporary wet joints and / or connecting steel plates are provided between adjacent composite plates 1. Specifically, in some embodiments, reference Fig.10 The connection between the composite plates 1 is made by connecting steel plates and bolts. A steel plate notch is reserved at the edge of the composite plate 1. A threaded sleeve is embedded in the specified position of the concrete during prefabrication. When connecting, a flexible gasket is first placed in the notch to reduce the collision between the connecting steel plate and the concrete. Then, the steel plate is placed in the notch and connected by bolts. In some embodiments, reference Fig.11 The composite plates 1 can also be connected by a removable temporary wet joint, with part of the steel plate left exposed at the edge of the composite plate 1 and holes reserved on the steel plate; when connecting, U-shaped steel bars are used to connect two adjacent composite plates 1 through the holes reserved on the steel plates, and flexible pads are placed at the joints to increase cushioning for movement between the plates and reduce mutual collision and wear of the plates.

[0058] In this embodiment, a foundation support layer 12 is provided at the bottom of the ventilation bracket. The fan bracket 5 is used as a cable tower and needs to withstand a large pressure. Therefore, a concrete foundation is poured under the bracket for stable support. A settlement observation pile 13 is further provided at the foundation support layer 12 to reflect the settlement state of the original soil hardening platform.

[0059] In this embodiment, a static level is installed on the cable tower support and is electrically connected to a computer and other equipment to realize automatic monitoring of the settlement stability of the cable tower support and reflect the stability of the original soil platform.

[0060] In this embodiment, a stress detection device 7 is provided on the inclined cable 4. The settlement of the backfill soil is determined by the change of the cable stress, and the sinking position is accurately determined. By monitoring the settlement of the platform and the stress of the cable, grouting is performed in time to lift the panel, thereby ensuring the horizontal stability of the platform panel and reducing the amount of grouting required to support the panel.

[0061] In some embodiments, reference Figure 3 The end of the composite plate 1 away from the tunnel entrance 9 can be cantilevered, and a supporting structure 17 is provided between the cantilevered end 101 of the composite plate 1 and the retaining structure 2 for support; wherein, a construction access road 18 is provided below the cantilevered end 101 of the composite plate 1, which is provided when the terrain is complex and vehicles need to pass from under the platform.

[0062] In some embodiments, a pulley block is provided on the cable tower support to cooperate with the inclined cable. The pulley block includes a plurality of fixed pulleys and a plurality of movable pulleys. The specific structure, principle, etc. can be implemented with reference to the prior art. By providing the pulley block to cooperate with the inclined cable, the traction force of the required slope anchor rod end on the inclined cable can be reduced, thereby reducing the anchoring force of the slope anchor rod, thereby effectively reducing the engineering workload of the slope anchor rod construction and reducing the requirements for the slope stratum conditions, thereby increasing the proportion of the traversable part of the material.

[0063] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A temporary working platform for a tunnel entrance with a high and steep slope, characterized in that: include: The retaining structure, as the platform foundation, comprises support piles for setting at the side slope of the tunnel opening, and a soil and rock backfill body is set between the support piles and the side slope; The composite slab includes a concrete layer at the upper layer and a steel plate layer at the lower layer, and the composite slab is respectively connected to the retaining structure and the original soil hardening platform; The supporting structure includes a grouting bag arranged between the top of the soil-rock backfill body and the bottom surface of the composite plate, and is used for grouting to support the composite plate when the soil-rock backfill body settles; The anchor rod inclined structure comprises an inclined cable, a protective anchor rod arranged on a slope and a cable tower support of a ventilator support arranged on a tunnel. The inclined cable passes through the top of the cable tower support and is respectively connected to the composite plate and the protective anchor rod.

2. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: An anti-slip pile structure is arranged on the slope at a preset angle within the soil and rock backfill body.

3. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: The composite plate is hinged to the original soil hardening platform through a pin arranged in the longitudinal direction, or the end of the composite plate is hinged to the original soil hardening platform through a force transmission anchor bolt and an elastic filler.

4. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: Temporary wet joints and / or connecting steel plates are arranged between adjacent composite plates.

5. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: A basic supporting layer is arranged at the bottom of the ventilator bracket.

6. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: A static level is installed on the cable tower support.

7. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: The stay cable is provided with a stress detection device.

8. The temporary working platform for a high and steep slope tunnel entrance according to claim 1, characterized in that: The composite plate is cantilevered at one end away from the tunnel opening, and a supporting structure is arranged between the cantilevered end of the composite plate and the retaining structure.

9. The temporary working platform for a high and steep slope tunnel entrance according to claim 8, characterized in that: A construction access road is arranged below the cantilevered end of the composite slab.

10. The temporary working platform for a high and steep slope tunnel entrance according to any one of claims 1 to 9, characterized in that: The cable tower support is provided with a pulley block for cooperating with the inclined cable.

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