Excavation support system and construction method of urban open-cut tunnel

Abstract

The present invention provides an urban open-cut tunnel excavation support system and a construction method. By adopting a standardized access road with anti-skid ribs that can be quickly spliced, driving safety and speed are improved, the possibility of instability of the foundation pit is reduced, and the construction speed is accelerated; by adopting a slope steel mesh quick-binding tire frame and a slope support standardized mobile operating platform for construction, the tire frame side plates of the slope steel mesh quick-binding tire frame are fixed by installing side plate fixings on the inner and outer sides, which speeds up the steel bar binding speed, is beneficial to the stability of the slope, and is convenient for construction personnel to operate; through the prefabricated assembly and assembly tower crane foundation technology, the prefabricated central component of the prefabricated assembly and assembly tower crane foundation is placed at the center position of the cushion layer, and the prefabricated symmetrical components are connected to the prefabricated central component on the cushion layer through embedded bars; the counterweight blocks are placed on the prefabricated symmetrical components, the construction speed is fast, the stability of the tower crane foundation is guaranteed, and the time for tunnel structure construction after the foundation pit is excavated can be effectively shortened.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to an excavation support system and a construction method for an urban open-cut underpass tunnel. Background Art

[0002] In today's society, with the rapid development of the economy, the country attaches great importance to various infrastructure projects. The transportation industry has also developed well under this form. The number of transportation projects in various regions continues to increase. Due to the great differences in the natural environment of various regions, tunnels need to be excavated in some areas during the construction of highway projects to optimize traffic conditions. In open-cut tunnel projects, foundation pit excavation is one of the most important links. How to quickly excavate the foundation pit in a changing environment and improve the progress of construction is particularly urgent.

[0003] The rapid construction method for open-cut tunnel excavation is to first open a temporary road, build a diversion channel, close the construction area, and excavate the foundation pit of the buried tunnel, with timely soil nail support as the guide. The foundation pit is excavated in sections and layers. In poor geological conditions and rainy weather, the construction temporary road is inconvenient to use, which affects the transportation of earth in the pit. After excavating a section, the tunnel structure of that section is constructed immediately. The construction speed of the tower crane foundation is slow, and the structure is unstable. These problems frequently occur on site, affecting tunnel construction.

[0004] In view of this, in view of the shortcomings of previous urban open-cut tunnel excavation and support construction, such as slow speed, inconvenience for car driving, poor operability of slope support personnel, and unstable tower crane foundation, a new urban open-cut tunnel excavation and support system and construction method is urgently needed to improve construction efficiency, improve construction quality, and ensure safe and reliable construction quality. Summary of the invention

[0005] The purpose of the present invention is to provide an urban open-cut tunnel excavation support system and construction method, aiming to solve the technical problems of slow urban open-cut tunnel excavation support construction speed, inconvenience of vehicle driving, poor operability of slope support personnel and unstable tower crane foundation.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] The urban open-cut tunnel excavation support system includes a standardized access road with fast-jointed limited ribbed anti-skid steel plates in the lower part of the foundation pit, a fast-binding frame for steel mesh on the slope, a prefabricated assembled tower crane foundation, and a standardized mobile operating platform for slope support;

[0008] The quick-joined limited ribbed anti-skid steel plate shaped walkway in the lower part of the foundation pit includes a ribbed steel plate and a perforated ear plate; the bottom of the ribbed steel plate is provided with a rib plate, and the two sides are provided with perforated ear plates; the adjacent ribbed steel plates are connected by the perforated ear plates on the sides to form a channel structure;

[0009] The slope steel mesh quick binding tire frame includes a tire frame side plate and a side plate fixing piece; the tire frame side plate is fixed by installing the side plate fixing piece inside and outside; the side plate fixing piece is fixed to the slope surface by soil nails passing through screw holes;

[0010] The prefabricated assembled tower crane foundation comprises a prefabricated central component, a prefabricated symmetrical component, a counterweight, embedded reinforcement and a steel plate; the prefabricated central component is placed at the center of the cushion layer and is provided with a reserved hole; the embedded reinforcement is installed in the reserved hole of the prefabricated central component, and the prefabricated symmetrical component is connected to the prefabricated central component on the cushion layer through the embedded reinforcement; the counterweight is placed on the prefabricated symmetrical component; the steel plate is fixed to the prefabricated symmetrical component through anchor bolts;

[0011] The slope support standardized mobile operation platform includes a moving device, a telescopic support frame and a platform plate; the lower end of the telescopic support frame is positioned on the moving device, and the upper end is positioned under the platform plate; the moving device is arranged on a track on the ground.

[0012] As a further improvement of the present invention, the quick-jointed, limited-position ribbed anti-skid steel plate standardized walkway in the lower part of the foundation pit also includes a connecting assembly; the lower ear plate of the perforated ear plate is fixed to the bottom of the left side of the ribbed steel plate; the upper ear plate of the perforated ear plate is fixed to the upper part of the right side of the ribbed steel plate; the perforated ear plates of adjacent ribbed steel plates are detachably and fixedly connected via the connecting assembly.

[0013] As a further improvement of the present invention, the connecting assembly includes a screw, a nut and a spacer; the screw passes through the holes of the upper ear plate and the lower ear plate, and the adjacent upper and lower ear plates are fixed by nuts from top to bottom, and the spacer is placed between the upper ear plate and the lower ear plate.

[0014] As a further improvement of the present invention, the slope steel mesh quick binding frame also includes steel bars and tightening hangers. After the steel bars are installed, the steel bars are tightened and fixed with the tightening hangers. The side plates of the frame are also provided with steel bar through holes.

[0015] As a further improvement of the present invention, the prefabricated assembled tower crane foundation also includes anchor holes, anchor bars and anchors, wherein the anchor holes are arranged on the prefabricated symmetrical components, and the anchor bars pass through the prefabricated central component and the prefabricated symmetrical components and are tensioned by the anchors.

[0016] As a further improvement of the present invention, the slope support standardized mobile operating platform includes a pulley, an L-shaped bracket, a base plate, a fixed base and a supporting top plate; the pulley is fixed to the bottom of the L-shaped bracket and moves on the track; the base plate is positioned on the L-shaped bracket; the fixed base is fixed to the base plate by fixing nails; the telescopic support frame is fixedly connected to the fixed base; the supporting top plate is installed on the top of the telescopic support frame and is connected to the bottom of the platform plate by fixing nails.

[0017] As a further improvement of the present invention, the slope support standardized mobile operating platform also includes an upper and lower platform for construction machinery, which is connected to the platform plate at one end by bolts passing through screw holes and is placed on the ground at the other end for the construction machinery to use up and down.

[0018] The urban open-cut tunnel excavation support and construction method includes the following steps:

[0019] S1. Construction preparation: Carry out on-site traffic control and prepare construction machinery and materials for entry;

[0020] S2. Construction of access roads and diversion channels: Before excavation, carry out precipitation construction, dig diversion channels in time, repair and clean the roads where vehicles pass in the surrounding areas to ensure smooth passage of vehicles;

[0021] S3. Layered excavation of foundation pit: The excavation of foundation pit must be carried out in sections, zones, layers and symmetry. Over-excavation is not allowed. The length of each section shall not be greater than the width of the foundation pit. Drainage measures shall be taken on the ground around the foundation pit. Surface water is strictly prohibited from entering the soil around the foundation pit.

[0022] S4. Construction of fixed access road with limited ribbed anti-skid steel plate: After the excavation of the foundation pit, it is particularly difficult for the muck truck to transport in the pit due to the effect of groundwater. For this reason, a temporary passage is paved in the foundation pit. Ribs are installed at the bottom of the ribbed steel plate, and ear plates are welded on both sides. The lower ear plate is fixed to the bottom of the left side of the ribbed steel plate, and the upper ear plate is fixed to the upper part of the right side of the ribbed steel plate. They are spliced ​​on the site. The screw passes through the holes of the upper ear plate and the lower ear plate, and the two ear plates are fixed by nuts from top to bottom. The pad is placed between the upper ear plate and the lower ear plate;

[0023] S5. Construction of the tire frame with fast binding of steel mesh on the slope: The side plates of the tire frame are fixed by installing side plate fixings on the inner and outer sides. The side plate fixings are fixed to the slope surface by passing soil nails through screw holes. The steel bar through holes are arranged on the side plates of the tire frame as required. After the steel bar is installed, the steel bar is tightened and fixed with tightening hanging plates;

[0024] S6. Construction of a standardized mobile operating platform for slope support: The track is laid on the ground, the pulley is fixed to the bottom of the L-shaped bracket and can move on the track. The bottom plate is placed on the L-shaped bracket and fixed on both sides by bolts. The fixed base is fixed to the bottom plate by fixing nails. The telescopic support frame is fixedly connected to the fixed base. The supporting top plate is installed on the top of the telescopic support frame and connected to the bottom of the platform plate by fixing nails. The upper and lower platforms of the construction machinery are connected to the platform plate at one end through the screw holes of the bolts, and the other end is placed on the ground for the construction machinery to go up and down. The slope surface is drilled and grouting is performed;

[0025] S7. Construction of prefabricated and assembled tower crane foundation: The prefabricated central component is placed at the center of the cushion layer, and a reserved hole is provided on it. The embedded reinforcement is installed in the reserved hole of the prefabricated central component. The prefabricated symmetrical components are connected to the prefabricated central component on the cushion layer through the embedded reinforcement. The counterweight is placed on the prefabricated symmetrical components. The steel pad is fixed to the prefabricated symmetrical components through anchor bolts. Anchor holes are provided on the prefabricated symmetrical components. The anchor reinforcement passes through the prefabricated central component and the prefabricated symmetrical components and is tensioned through anchors.

[0026] S8, main structure construction;

[0027] S9. Backfill on both sides of the tunnel structure.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present application improves driving safety and speed, reduces the possibility of instability of the foundation pit, and speeds up construction by adopting a standardized access road with anti-skid ribs that can be quickly spliced. It also speeds up the steel bar tying process by adopting a slope steel mesh rapid binding frame and a slope support standardized mobile operating platform for construction. This is beneficial to the stability of the slope and facilitates operation by construction personnel. The prefabricated and assembled tower crane foundation technology ensures a fast construction speed, ensures the stability of the tower crane foundation, and can effectively shorten the time for tunnel structure construction after foundation pit excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure of a single-body limited ribbed anti-skid steel plate standardized walkway;

[0033] Figure 3 This is a schematic diagram of the quick splicing structure of the fixed-type access road with limited ribbed anti-skid steel plates;

[0034] Figure 4 This is a schematic diagram of the splicing structure of the ear plate with holes;

[0035] Figure 5 This is a top view of the structure of the quick-binding frame for the slope steel mesh;

[0036] Figure 6 It is a schematic diagram of the tire frame side plate structure;

[0037] Figure 7 1 is a schematic diagram of the structure of the side panel fixings;

[0038] Figure 8 It is a schematic diagram of the prefabricated assembled tower crane foundation structure;

[0039] Fig. 9 It is a schematic diagram of the connection between the prefabricated symmetrical components and the prefabricated central components;

[0040] Fig.10 It is the front view of the prefabricated assembled tower crane foundation structure;

[0041] Fig.11 It is a side view of the structure of the standardized mobile operating platform for slope support;

[0042] Fig.12 This is the front view of the structure of the standardized mobile operating platform for slope support;

[0043] Fig.13 It is a side view of the upper and lower platform structure of the construction machinery;

[0044] Description of the numbers in the figure:

[0045] 1. The lower part of the foundation pit is quickly spliced ​​with limited ribbed anti-skid steel plates to form a standardized walkway; 11. Ribbed steel plates; 111. Rib plates; 12. Ear plates with holes; 121. Upper ear plates; 122. Lower ear plates; 13. Connecting components; 131. Screws; 132. Nuts; 133. Pads; 2. The slope steel mesh is quickly tied to the tire frame; 21. The tire frame side plates; 22. The side plate fixings; 23. Steel bars; 24. Tighten the hanging plates; 25. Soil nails; 3. Prefabricated and assembled tower crane foundation; 31. Prefabricated central component; 32. Prefabricated symmetrical components; 33. Counterweight; 34. Embedded reinforcement; 35. Steel pad; 36. Anchor hole; 37. Anchor reinforcement; 38. Anchor; 39. Pad; 4. Slope support standardized mobile operating platform; 41. Moving device; 42. Telescopic support frame; 43. Platform plate; 44. Pulley; 45. L-shaped bracket; 46. Bottom plate; 47. Fixed base; 48. Support top plate; 49. Construction machinery upper and lower platforms; 5. Track; 6. Construction machinery. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Combined with Figures 1 to 13 The present invention provides an urban open-cut tunnel excavation support system and construction method, aiming to solve the technical problems of slow urban open-cut tunnel excavation support construction speed, inconvenience in vehicle driving, poor operability of slope support personnel and unstable tower crane foundation.

[0048] Specifically, the urban open-cut tunnel excavation support system includes a standardized access road with a ribbed anti-skid steel plate 1 at the bottom of the foundation pit, a fast-jointed steel mesh fast-binding frame 2 on the slope, a prefabricated assembled tower crane foundation 3 and a standardized mobile operating platform 4 for slope support;

[0049] The bottom of the foundation pit quick splicing limit ribbed anti-skid steel plate shaped walkway 1 comprises a ribbed steel plate 11 and a perforated ear plate 12; a rib plate 111 is positioned at the bottom of the ribbed steel plate 11, and perforated ear plates 12 are positioned on both sides; adjacent ribbed steel plates 11 are connected by the perforated ear plates 12 on the sides to form a channel structure;

[0050] The slope steel mesh quick binding tire frame 2 includes a tire frame side plate 21 and a side plate fixing member 22; the tire frame side plate 21 is fixed by installing the side plate fixing member 22 inside and outside; the side plate fixing member 22 is fixed to the slope surface by soil nails 25 passing through screw holes;

[0051] The prefabricated assembled tower crane foundation 3 includes a prefabricated central component 31, a prefabricated symmetrical component 32, a counterweight 33, an embedded rib 34 and a steel plate 35; the prefabricated central component 31 is placed at the center of a cushion layer 39, on which a reserved hole is provided; the embedded rib 34 is installed in the reserved hole of the prefabricated central component 31, and the prefabricated symmetrical component 32 is connected to the prefabricated central component 31 on the cushion layer 39 through the embedded rib 34; the counterweight 33 is placed on the prefabricated symmetrical component 32; the steel plate 35 is fixed to the prefabricated symmetrical component 32 through anchor bolts;

[0052] The slope support standardized mobile operation platform 4 includes a moving device 41, a telescopic support frame 42 and a platform plate 43; the lower end of the telescopic support frame 42 is positioned on the moving device 41, and the upper end is positioned under the platform plate 43; the moving device 41 is arranged on a track 5 on the ground.

[0053] Furthermore, the quick-jointed, limited-position ribbed anti-skid steel plate standardized walkway 1 in the lower part of the foundation pit also includes a connecting component 13; the lower ear plate 122 of the perforated ear plate 12 is fixed to the bottom of the left side of the ribbed steel plate 11; the upper ear plate 121 of the perforated ear plate 12 is fixed to the upper part of the right side of the ribbed steel plate 11; the perforated ear plates 12 of adjacent ribbed steel plates 11 are detachably and fixedly connected via the connecting component 13.

[0054] Furthermore, the connecting assembly 13 includes a screw 131, a nut 132 and a pad 133; the screw 131 passes through the holes of the upper ear plate 121 and the lower ear plate 122, and fixes the adjacent upper and lower ear plates 122 up and down through the nut 132, and the pad 133 is placed between the upper ear plate 121 and the lower ear plate 122.

[0055] Furthermore, the slope steel mesh quick-binding frame 2 also includes steel bars 23 and tightening hangers 24. After the steel bars 23 are installed, the steel bars 23 are tightened and fixed with the tightening hangers 24. The frame side plates 21 are also provided with steel bar through holes.

[0056] Furthermore, the prefabricated assembled tower crane foundation 3 also includes anchor holes 36, anchor bars 37 and anchors 38. The anchor holes 36 are arranged on the prefabricated symmetrical components 32, and the anchor bars 37 pass through the prefabricated central component 31 and the prefabricated symmetrical components 32, and are tensioned by the anchors 38.

[0057] Preferably, the slope support standardized mobile operating platform 4 includes a pulley 44, an L-shaped bracket 45, a base plate 46, a fixed base 47 and a supporting top plate 48; the pulley 44 is fixed to the bottom of the L-shaped bracket 45 and moves on the track 5; the base plate 46 is positioned on the L-shaped bracket 45; the fixed base 47 is fixed to the base plate 46 by fixing nails; the telescopic support frame 42 is fixedly connected to the fixed base 47; the supporting top plate 48 is installed on the top of the telescopic support frame 42, and is connected to the bottom of the platform plate 43 by fixing nails; it should be noted that in this embodiment, the mobile device 41 adopts the structure of the pulley 44, which is simpler and more practical.

[0058] Furthermore, the slope support standardized mobile operation platform 4 also includes an upper and lower platform 49 for construction machinery, and the upper and lower platform 49 for construction machinery is connected to the platform plate 43 at one end by bolts passing through screw holes, and the other end is placed on the ground for the construction machinery 6 to use up and down.

[0059] The urban open-cut tunnel excavation support and construction method includes the following steps:

[0060] S1. Construction preparation: Make good on-site traffic control and prepare construction machinery and materials for entry;

[0061] S2. Construction of access roads and diversion channels: Before excavation, carry out precipitation construction, dig diversion channels in time, repair and clean the roads where vehicles pass in the surrounding areas to ensure smooth passage of vehicles;

[0062] S3. Layered excavation of foundation pit: The excavation of foundation pit must be carried out in sections, zones, layers and symmetry. Over-excavation is not allowed. The length of each section shall not be greater than the width of the foundation pit. Drainage measures shall be taken on the ground around the foundation pit. Surface water is strictly prohibited from entering the soil around the foundation pit.

[0063] S4. Construction of fixed access road with limited ribbed anti-skid steel plate: After the foundation pit is excavated, it is particularly difficult for the muck truck to transport in the pit due to the effect of groundwater. For this reason, a temporary passage is paved in the foundation pit. A ribbed plate 111 is installed at the bottom of the ribbed steel plate 11, and ear plates 112 are welded on both sides. The lower ear plate 122 is fixed to the bottom of the left side of the ribbed steel plate 11, and the upper ear plate 121 is fixed to the upper part of the right side of the ribbed steel plate 11. The splicing is carried out on the site. The screw 131 passes through the holes of the upper ear plate 121 and the lower ear plate 122, and the two ear plates 112 are fixed by nuts 132 from top to bottom. The pad 133 is placed between the upper ear plate 121 and the lower ear plate 122;

[0064] S5. Construction of the tire frame 2 with fast tying of the steel mesh on the slope: The tire frame side plates 21 are fixed by installing the side plate fixing members 22 on the inner and outer sides. The side plate fixing members 22 are fixed to the slope surface by passing the soil nails 25 through the screw holes. The steel bar through holes are arranged on the tire frame side plates 21 as required. After the steel bars 23 are installed, the steel bars 23 are tightened and fixed by tightening the hanging pieces 24.

[0065] S6. Construction of the mobile operating platform 4 for slope support: the track 5 is laid on the ground, the pulley 44 is fixed to the bottom of the L-shaped bracket 45 and can move on the track 5, the bottom plate 46 is placed on the L-shaped bracket 45 and fixed on both sides by bolts, the fixed base 47 is fixed to the bottom plate 46 by fixing nails, the telescopic support frame 42 is fixedly connected to the fixed base 47, the supporting top plate 48 is installed on the top of the telescopic support frame 42 and connected to the bottom of the platform plate 43 by fixing nails, the upper and lower platforms 49 of the construction machinery are connected to the platform plate 43 at one end by bolts passing through the screw holes, and the other end is placed on the ground for the construction machinery 6 to use up and down, and the slope surface is drilled and grouted;

[0066] S7, construction of prefabricated assembled tower crane foundation 3: the prefabricated central component 31 is placed at the center of the cushion layer 39, a reserved hole is provided on the prefabricated central component 31, the embedded reinforcement 34 is installed in the reserved hole of the prefabricated central component 31, the prefabricated symmetrical components 32 are connected to the prefabricated central component 31 on the cushion layer 39 through the embedded reinforcement 34, the counterweight 33 is placed on the prefabricated symmetrical components 32, the steel pad 35 is fixed to the prefabricated symmetrical components 32 through anchor bolts, the anchor holes 36 are provided on the prefabricated symmetrical components 32, the anchor reinforcement 37 passes through the prefabricated central component 31 and the prefabricated symmetrical components 32, and is tensioned through the anchor 38;

[0067] S8, main structure construction;

[0068] S9. Backfill on both sides of the tunnel structure.

[0069] The present application improves driving safety and speed, reduces the possibility of instability of the foundation pit, and speeds up construction by adopting a standardized access road with anti-skid ribs 111 that can be quickly spliced; by adopting a slope steel mesh rapid binding frame 2 and a slope support standardized mobile operating platform 4 for construction, the speed of steel bar binding is accelerated, which is beneficial to the stability of the slope and convenient for construction personnel to operate; through the prefabricated assembly assembled tower crane foundation 3 technology, the construction speed is fast, the stability of the tower crane foundation is guaranteed, and the time for tunnel structure construction after foundation pit excavation can be effectively shortened.

[0070] The process of this application is simple to operate, the construction efficiency and precision are improved, the high-altitude operation time is reduced, and no special equipment is required; less equipment and personnel are required, the labor intensity is low, and the site occupancy is small; the project cost is reduced; this method has achieved good results in the construction of engineering example projects, and has wide promotion and application value under similar conditions, and the economic and social benefits are very obvious.

[0071] It should be noted that some parts not described in detail in the present invention belong to the well-known technology in the art, or can be directly purchased from the market, and those skilled in the art can obtain them without creative work. The specific connection method is extremely widely used in this art or in daily life, and will not be described in detail here.

[0072] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0073] 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 at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0074] 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0077] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. Urban open-cut tunnel excavation support system, characterized by: It includes a standardized access road with ribbed anti-skid steel plates that can be quickly spliced ​​in the lower part of the foundation pit, a fast-binding frame for steel mesh on the slope, a prefabricated assembled tower crane foundation, and a standardized mobile operating platform for slope support; The quick-joined limited ribbed anti-skid steel plate shaped walkway in the lower part of the foundation pit includes a ribbed steel plate and a perforated ear plate; the bottom of the ribbed steel plate is provided with a rib plate, and the two sides are provided with perforated ear plates; the adjacent ribbed steel plates are connected by the perforated ear plates on the sides to form a channel structure; The slope steel mesh quick binding tire frame includes a tire frame side plate and a side plate fixing piece; the tire frame side plate is fixed by installing the side plate fixing piece inside and outside; the side plate fixing piece is fixed to the slope surface by soil nails passing through screw holes; The prefabricated assembled tower crane foundation comprises a prefabricated central component, a prefabricated symmetrical component, a counterweight, embedded reinforcement and a steel plate; the prefabricated central component is placed at the center of the cushion layer and is provided with a reserved hole; the embedded reinforcement is installed in the reserved hole of the prefabricated central component, and the prefabricated symmetrical component is connected to the prefabricated central component on the cushion layer through the embedded reinforcement; the counterweight is placed on the prefabricated symmetrical component; the steel plate is fixed to the prefabricated symmetrical component through anchor bolts; The slope support standardized mobile operation platform includes a moving device, a telescopic support frame and a platform plate; the lower end of the telescopic support frame is positioned on the moving device, and the upper end is positioned under the platform plate; the moving device is arranged on a track on the ground.

2. The urban open-cut tunnel excavation support system according to claim 1 is characterized by: The quick-jointed, limited-position, ribbed anti-skid steel plate standardized walkway in the lower part of the foundation pit also includes a connecting assembly; the lower ear plate of the perforated ear plate is fixed to the bottom of the left side of the ribbed steel plate; the upper ear plate of the perforated ear plate is fixed to the upper part of the right side of the ribbed steel plate; the perforated ear plates of adjacent ribbed steel plates are detachably and fixedly connected via the connecting assembly.

3. The urban open-cut tunnel excavation support system according to claim 2 is characterized by: The connecting assembly includes a screw, a nut and a cushion block; the screw passes through the holes of the upper ear plate and the lower ear plate, and fixes the adjacent upper and lower ear plates through nuts, and the cushion block is placed between the upper ear plate and the lower ear plate.

4. The urban open-cut tunnel excavation support system according to claim 1 is characterized in that: The slope steel mesh quick binding frame also includes steel bars and tightening hangers. After the steel bars are installed, the steel bars are tightened and fixed with the tightening hangers. The side plates of the frame are also provided with steel bar through holes.

5. The urban open-cut tunnel excavation support system according to claim 1 is characterized by: The prefabricated assembled tower crane foundation also includes anchor holes, anchor bars and anchors. The anchor holes are arranged on the prefabricated symmetrical components. The anchor bars pass through the prefabricated central component and the prefabricated symmetrical components and are tensioned by the anchors.

6. The urban open-cut tunnel excavation support system according to claim 1 is characterized by: The slope support standardized mobile operating platform includes a pulley, an L-shaped bracket, a base plate, a fixed base and a supporting top plate; the pulley is fixed to the bottom of the L-shaped bracket and moves on the track; the base plate is positioned on the L-shaped bracket; the fixed base is fixed to the base plate by fixing nails; the telescopic support frame is fixedly connected to the fixed base; the supporting top plate is installed on the top of the telescopic support frame and is connected to the bottom of the platform plate by fixing nails.

7. The urban open-cut tunnel excavation support system according to claim 1 is characterized by: The standardized mobile operating platform for slope support also includes upper and lower platforms for construction machinery. The upper and lower platforms for construction machinery are connected to the platform plate at one end by bolts passing through screw holes, and the other end is placed on the ground for the construction machinery to use up and down.

8. An urban open-cut tunnel excavation support and construction method, based on the urban open-cut tunnel excavation support system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Construction preparation: Carry out on-site traffic control and prepare construction machinery and materials for entry; S2. Construction of access roads and diversion channels: Before excavation, carry out precipitation construction, dig diversion channels in time, repair and clean the roads where vehicles pass in the surrounding areas to ensure smooth passage of vehicles; S3. Layered excavation of foundation pit: The excavation of foundation pit must be carried out in sections, zones, layers and symmetry. Over-excavation is not allowed. The length of each section shall not be greater than the width of the foundation pit. Drainage measures shall be taken on the ground around the foundation pit. Surface water is strictly prohibited from entering the soil around the foundation pit. S4. Construction of fixed access road with limited ribbed anti-skid steel plate: After the excavation of the foundation pit, it is particularly difficult for the muck truck to transport in the pit due to the effect of groundwater. For this reason, a temporary passage is paved in the foundation pit. Ribs are installed at the bottom of the ribbed steel plate, and ear plates are welded on both sides. The lower ear plate is fixed to the bottom of the left side of the ribbed steel plate, and the upper ear plate is fixed to the upper part of the right side of the ribbed steel plate. They are spliced ​​on the site. The screw passes through the holes of the upper ear plate and the lower ear plate, and the two ear plates are fixed by nuts from top to bottom. The pad is placed between the upper ear plate and the lower ear plate; S5. Construction of the tire frame with fast binding of steel mesh on the slope: The side plates of the tire frame are fixed by installing side plate fixings on the inner and outer sides. The side plate fixings are fixed to the slope surface by passing soil nails through screw holes. The steel bar through holes are arranged on the side plates of the tire frame as required. After the steel bar is installed, the steel bar is tightened and fixed with tightening hanging plates; S6. Construction of a standardized mobile operating platform for slope support: The track is laid on the ground, the pulley is fixed to the bottom of the L-shaped bracket and can move on the track. The bottom plate is placed on the L-shaped bracket and fixed on both sides by bolts. The fixed base is fixed to the bottom plate by fixing nails. The telescopic support frame is fixedly connected to the fixed base. The supporting top plate is installed on the top of the telescopic support frame and connected to the bottom of the platform plate by fixing nails. The upper and lower platforms of the construction machinery are connected to the platform plate at one end through the screw holes of the bolts, and the other end is placed on the ground for the construction machinery to go up and down. The slope surface is drilled and grouting is performed; S7. Construction of prefabricated and assembled tower crane foundation: The prefabricated central component is placed at the center of the cushion layer, and a reserved hole is provided on it. The embedded reinforcement is installed in the reserved hole of the prefabricated central component. The prefabricated symmetrical components are connected to the prefabricated central component on the cushion layer through the embedded reinforcement. The counterweight is placed on the prefabricated symmetrical components. The steel pad is fixed to the prefabricated symmetrical components through anchor bolts. Anchor holes are provided on the prefabricated symmetrical components. The anchor reinforcement passes through the prefabricated central component and the prefabricated symmetrical components and is tensioned through anchors. S8, main structure construction; S9. Backfill on both sides of the tunnel structure.

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