Full-recovery type steel composite structure vertical shaft supporting system and method

Abstract

The invention discloses a full-recovery type steel composite structure vertical shaft supporting system and method.The system comprises an annular steel plate and a plurality of inner supporting assemblies installed on the annular steel plate, and the annular steel plate sinks before a vertical shaft is excavated and is pulled out after backfilling is completed; wherein the multiple inner supporting assemblies are distributed at intervals in the vertical direction, each inner supporting assembly comprises a profile steel ring support installed on the annular steel plate, a gap exists between the profile steel ring support and the annular steel plate, and an inflation air bag is arranged in the gap so as to pre-tighten the profile steel ring support; the sides, away from the annular steel plate, of every two adjacent profile steel ring supports are connected through a vertical connecting piece, and the inner supporting assemblies are increased layer by layer in the foundation pit excavation process and recycled layer by layer in the backfilling process. The construction efficiency is greatly improved, repeated utilization can be achieved, and the project construction cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of shaft support, and particularly relates to a fully recyclable steel combined structure shaft support system and method. Background Technique

[0002] A shaft is one of the most common construction auxiliary structures during the construction of urban renewal pipe network projects. During the process of trench laying or underground long-distance line crossing, shafts need to be set at certain intervals to achieve the functions of ventilation and transportation of related materials, and to speed up the project progress. Due to the characteristics of small floor area and less interference to surrounding construction during shaft construction, shaft structures are also commonly used in pipe jacking construction of urban underground pipelines (such as water supply and drainage, power, communication pipelines, etc.) to provide working space for pipe jacking construction, and are widely used in water intake, water diversion, ventilation, slag chutes, and air supply in water conservancy and hydropower projects;

[0003] During the shaft excavation process, in order to control the formation pressure and maintain the stability of the shaft wall, shaft support is often set to prevent phenomena such as shaft collapse, ensuring safe production. Currently, reinforced concrete shaft walls are often used for shafts, excavating one layer and supporting one layer. Not only is the construction slow, but the required cost is also high. Moreover, after the temporary support is completed, it cannot be recycled, resulting in a large construction cost and problems such as resource waste and environmental pollution. Summary of the Invention

[0004] The purpose of the invention is to provide a fully recyclable steel combined structure shaft support system and method to overcome the defects of the prior art. The annular steel plate and the inner support assembly are separated from each other and can be quickly connected. During the temporary support process, an inflatable airbag is used to pre-tighten the steel ring supports on the annular steel plate to form a rigid-flexible collaborative inner support structure, which has high strength and small occupied space, and can provide a larger working space for construction inside the shaft. At the same time, the pressure of the inflatable airbag can be controlled to make the inner support assembly and the annular steel plate adaptively pre-tighten. During the backfilling process, the inner support assembly is recycled while backfilling, and finally the annular steel plate is recycled to achieve the full recycling of the support system, which not only greatly improves the construction efficiency, but also can be reused repeatedly, reducing the project construction cost. The overall structure of the support system is simple, and the operation processes of support and recycling are very convenient, improving the construction efficiency while reducing the cost.

[0005] The purpose of the invention is achieved through the following technical solutions:

[0006] A fully recyclable steel combined structure shaft support system includes an annular steel plate and a plurality of inner support assemblies installed on the annular steel plate. The annular steel plate sinks before shaft excavation and is withdrawn after backfilling is completed;

[0007] Among them, a plurality of the inner support components are distributed at intervals in the vertical direction. The inner support component includes a profiled steel ring support installed on the annular steel plate. There is a gap between the profiled steel ring support and the annular steel plate, and an inflatable airbag is arranged in the gap to pre-tighten the profiled steel ring support. One side of two adjacent profiled steel ring supports away from the annular steel plate is connected by a vertical connecting member. The inner support components are increased layer by layer during the foundation pit excavation process and recovered layer by layer during the backfilling process;

[0008] In one embodiment, in each layer of the radial support structure, longitudinal grouting pipes and circumferential grouting pipes are arranged on both sides of the annular steel plate, and the longitudinal grouting pipes and the circumferential grouting pipes extend in mutually perpendicular directions;

[0009] Through this embodiment, that is, by arranging longitudinal grouting pipes and circumferential grouting pipes on the inner and outer sides of the annular steel plate, when facing relatively hard soil layers, the frictional resistance of the soil layer to the annular steel plate can be effectively reduced by injecting bentonite thixotropic slurry, thereby reducing the construction difficulty during the sinking and pulling out of the annular steel plate and improving the construction efficiency;

[0010] In one embodiment, the annular steel plate is spliced by a plurality of sub-plate segments, and a lock ring beam is arranged at the top of the annular steel plate;

[0011] Through this embodiment, that is, using standardized sub-plate segments to form an integral annular steel plate, the plurality of sub-plate segments are convenient for transportation and can be adjusted according to the actual size of the shaft to meet different support requirements. At the same time, the arranged lock ring beam can ensure uniform force transmission and stable steel plate during the sinking of the annular steel plate, so that the top of the support steel plate is stressed as a whole during the sinking construction;

[0012] In one embodiment, a quick-release bracket for fixing the profiled steel ring support is further installed on the annular steel plate, and the quick-release bracket is connected to the annular steel plate through a connection buckle arranged on the inner side of the annular steel plate;

[0013] In one embodiment, adjacent sub-plate segments in the horizontal direction are connected together by vertical connecting plates, and adjacent sub-plate segments in the vertical direction are connected together by circumferential connecting plates. The vertical connecting plates and the circumferential connecting plates are both installed on the sub-plate segments through fixing bolts;

[0014] The present invention also provides a full-recovery profiled steel composite structure shaft support method. Based on the above full-recovery profiled steel composite structure shaft support system, it includes the following steps:

[0015] Step S1, sink the annular steel plate through a vibrating device. During the sinking process of the annular steel plate, add sub-plate segments to the annular steel plate layer by layer in the vertical direction;

[0016] Step S2: During the shaft tunneling process, the foundation pit is excavated from top to bottom. For each excavation of a foundation pit with a preset height, an inner support assembly is installed until the designed support bottom surface is excavated;

[0017] Step S3: During the backfilling process, the inner support assemblies are removed layer by layer from bottom to top. For each removal of one layer of the inner support assembly, a section of the foundation pit with a preset height is backfilled until the ground surface is reached;

[0018] Step S4: Pull out the annular steel plate upwards to complete the full recovery operation of the support system;

[0019] Wherein, the distance between adjacent two layers of the inner support assemblies is the same, and the preset height does not exceed the distance between adjacent two layers of the inner support assemblies;

[0020] Through this embodiment, the shaft is temporarily supported by using a steel composite structure. The annular steel plate and the inner support assembly are separated from each other and cooperate with each other. During the shaft tunneling process, the inner support assemblies are installed layer by layer on the annular steel plate. At the same time, during the backfilling process, the radial support structure is recovered layer by layer. Finally, the full recovery of the support system is realized by pulling out the annular steel plate. The operation is simple, which greatly improves the construction efficiency while ensuring the support effect. At the same time, the support system can be reused repeatedly, reducing the construction cost of the project;

[0021] In one embodiment, in step S1, it further includes:

[0022] Using vertical connecting plates, circumferential connecting plates and fixing bolts to form an integral annular steel plate from sub-plate segments, and installing a collar ring beam at the top of the annular steel plate;

[0023] Through this embodiment, that is, an integral annular steel plate is formed by using standardized sub-plate segments. The multiple sub-plate segments are convenient for transportation and can be adjusted according to the actual size of the shaft to meet different support requirements. At the same time, the installed collar ring beam can ensure uniform force transmission and the stability of the steel plate when the annular steel plate sinks, enabling the top of the support steel plate to be stressed as a whole during the sinking construction;

[0024] In one embodiment, in step S1, it further includes:

[0025] During the sinking process of the annular steel plate, bentonite thixotropic mud is injected into the foundation pit along both sides of the annular steel plate through longitudinal grouting pipes and circumferential grouting pipes to reduce the sinking resistance;

[0026] In one embodiment, in step S2, for each excavation of a foundation pit with a preset height, installing an inner support assembly includes:

[0027] Using the bracket buckle inside the annular steel plate to install a quick-release bracket, and then installing a steel ring brace and an inflatable airbag on the quick-release bracket;

[0028] With this embodiment, that is, by using a quick-release bracket that matches the bracket buckle, it is convenient to quickly disassemble and assemble the profiled steel ring support and the inflatable airbag on the annular steel plate, improving the construction efficiency.

[0029] In one embodiment, in step S2, it further includes:

[0030] Inflate the inflatable airbag. When its air pressure reaches the preset air pressure, seal the airbag inflation port, and then fix the profiled steel ring support by using the support connection bolts and the ring support connection ear plates.

[0031] The beneficial effects of the present invention are as follows:

[0032] The annular steel plate and the internal support assembly are separated from each other and can be quickly connected. During the temporary support process, the inflatable airbag is used to pre-tighten the profiled steel ring support on the annular steel plate to form a rigid-flexible collaborative internal support structure, which has high strength and small occupied space, can provide a larger working space for the construction inside the shaft, and can also make the internal support assembly and the annular steel plate adaptively pre-tighten by controlling the pressure of the inflatable airbag. At the same time, during the backfilling process, the internal support assembly is recycled while backfilling, and finally the annular steel plate is recycled to realize the full recycling of the support system, which not only greatly improves the construction efficiency, but also can be reused repeatedly, reducing the project construction cost. The overall structure of the support system is simple, and the operation processes of support and recycling are very convenient, improving the construction efficiency while reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Shows a schematic structural view of the support system of the present invention;

[0034] Figure 2 Shows a schematic structural view of the support system of the present invention at the profiled steel ring support;

[0035] Figure 3 Shows a schematic structural view of the support system of the present invention at the connecting plate;

[0036] Figure 4 Shows a schematic front structural view of the support system of the present invention when unfolded;

[0037] Figure 5 Shows a schematic plan structural view of the profiled steel ring support of the support system of the present invention;

[0038] Figure 6 Shows a schematic cross-sectional structural view of the profiled steel ring support of the support system of the present invention;

[0039] Figure 7 Shows a schematic structural view of the inflatable airbag of the support system of the present invention;

[0040] Figure 8Shows the schematic connection diagram of the profiled steel ring brace of the support system of the present invention;

[0041] Figure 9 Shows the elevation schematic diagram of injecting bentonite thixotropic slurry into the support system of the present invention;

[0042] Figure 10 Shows the plan schematic diagram of injecting bentonite thixotropic slurry into the support system of the present invention;

[0043] Figure 11 Shows the schematic diagram of the support system of the present invention driven into the foundation pit;

[0044] Figure 12 Shows the schematic diagram of the support system of the present invention during the excavation of the foundation pit and the gradual addition of internal support components layer by layer;

[0045] Figure 13 Schematic diagram of the support system of the present invention during the backfilling of the foundation pit and the gradual recovery of internal support components layer by layer.

[0046] In the drawings, the same components are denoted by the same reference numerals, and the drawings are not drawn to actual scale.

[0047] Reference numerals:

[0048] 1 - Circular steel plate, 2 - Profiled steel ring brace, 3 - Inflatable airbag, 4 - Vertical connection piece, 5 - Quick-release support, 6 - Longitudinal grouting pipe, 7 - Circumferential grouting pipe, 8 - Vertical connection plate, 9 - Circumferential connection plate, 10 - Fixed bolt, 11 - Support buckle, 12 - Ring brace connection ear plate, 13 - Support connection bolt, 14 - Airbag inflation port, 15 - Air pressure detection device, 16 - Vertical connection ear plate, 17 - Vertical connection bolt, 18 - Locking ring beam, 19 - Bentonite thixotropic slurry. Detailed implementation manners

[0049] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0050] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0051] In one embodiment, the present invention provides a fully recoverable profiled steel composite structure shaft support system, as Figure 1As shown, it includes a circular steel plate 1 and a plurality of internal support components installed on the circular steel plate 1. The circular steel plate 1 sinks before the shaft excavation and is withdrawn after the backfill is completed;

[0052] Among them, the plurality of internal support components are distributed at intervals in the vertical direction. The internal support component includes a profiled steel ring support 2 installed on the circular steel plate 1. There is a gap between the profiled steel ring support 2 and the circular steel plate 1. An inflatable airbag 3 is arranged in the gap to pre-tighten the profiled steel ring support 2. The sides of adjacent two profiled steel ring supports 2 away from the circular steel plate 1 are connected by a vertical connecting member 4. The internal support components are increased layer by layer during the foundation pit excavation process and recovered layer by layer during the backfill process;

[0053] It should be noted that in this embodiment, the circular steel plate 1 and the internal support components are separated from each other, and at the same time, they can be quickly disassembled and assembled. During the temporary support process, the inflatable airbag 3 is used to pre-tighten the profiled steel ring support 2 on the circular steel plate 1 to form a rigid-flexible collaborative internal support structure, which has high strength and small occupied space, can provide a larger working space for the construction inside the shaft, and can also make the internal support components and the circular steel plate 1 adaptively pre-tighten by controlling the pressure of the inflatable airbag 3. At the same time, during the backfill process, the internal support components are recovered while backfilling, and finally the circular steel plate 1 is recovered, realizing the full recovery of the support system, which not only greatly improves the construction efficiency, but also can be reused repeatedly, reducing the project construction cost. The overall structure of the support system is simple, and the operation processes of support and recovery are very convenient, which improves the construction efficiency while reducing the cost;

[0054] Specifically, as Figure 6 and Figure 7 shown, the quick-release bracket 5 is installed by using the bracket buckle 11. The profiled steel ring support 2 and the inflatable airbag 3 located inside the profiled steel ring support 2 are installed on the quick-release bracket 5, and then the inflatable airbag 3 is inflated. When the data displayed by the air pressure monitoring device reaches the preset air pressure, the airbag inflation port 14 is closed to complete the internal support pre-tightening, and the fixed support connection bolt 13 is used to lock the internal support. And when the construction of two layers of supports in a standard section is completed, the vertical connecting member 4 is installed through the vertical connecting ear plate 16 and the vertical connecting bolt 17;

[0055] In one embodiment, as Figures 2 to 5 shown, longitudinal grouting pipes 6 and circumferential grouting pipes 7 are arranged on both sides of the circular steel plate 1. The longitudinal grouting pipes 6 and the circumferential grouting pipes 7 extend in mutually perpendicular directions. That is, by arranging the longitudinal grouting pipes 6 and the circumferential grouting pipes 7 on the inner and outer sides of the circular steel plate 1, when facing a relatively hard soil layer, the frictional resistance of the soil layer on the circular steel plate 1 can be effectively reduced by injecting bentonite thixotropic slurry 19, thereby reducing the construction difficulty when sinking and pulling out the circular steel plate 1 and improving the construction efficiency;

[0056] In one embodiment, as Figure 1As shown, the annular steel plate 1 is formed by splicing multiple sub-plate segments. A locking collar beam 18 is provided at the top of the annular steel plate 1. That is, the standardized sub-plate segments are used to form an integrated annular steel plate 1. The multiple sub-plate segments are convenient for transportation and can be adjusted according to the actual size of the shaft to meet different support requirements. At the same time, the provided locking collar beam 18 can ensure uniform force transmission and the stability of the steel plate when the annular steel plate 1 sinks, so that the top of the support steel plate is stressed as a whole during the sinking construction;

[0057] In one embodiment, as Figure 1 and Figure 8 shown, a quick-release bracket 5 for fixing the steel ring brace 2 is also installed on the annular steel plate 1. The quick-release bracket 5 is connected to the annular steel plate 1 through a connection buckle provided on the inner side of the annular steel plate 1;

[0058] In one embodiment, as Figure 4 and Figure 5 shown, the adjacent sub-plate segments in the horizontal direction are connected together by vertical connecting plates 8, and the adjacent sub-plate segments in the vertical direction are connected together by circumferential connecting plates 9. Both the vertical connecting plates 8 and the circumferential connecting plates 9 are installed on the sub-plate segments through fixing bolts 10;

[0059] In one embodiment, the present invention also provides a full-recovery steel section combined structure shaft support method, including the following steps:

[0060] Step S1: Sink the annular steel plate through a vibrating device. During the sinking process of the annular steel plate, add sub-plate segments to the annular steel plate layer by layer in the vertical direction. Use vertical connecting plates, circumferential connecting plates, and fixing bolts to form an integrated annular steel plate of the sub-plate segments, and install a locking collar beam at the top of the annular steel plate. During the sinking process of the annular steel plate, inject bentonite thixotropic mud into the foundation pit along both sides of the annular steel plate through longitudinal grouting pipes and circumferential grouting pipes to reduce the sinking resistance;

[0061] Step S2: During the shaft excavation process, excavate the foundation pit from top to bottom. Install an inner support component for each section of the foundation pit excavated to a preset height until the designed support bottom surface is excavated. Install a quick-release bracket using the bracket buckle on the inner side of the annular steel plate, then install a steel ring brace and an inflatable airbag on the quick-release bracket. Inflate the inflatable airbag. When the air pressure reaches the preset air pressure, close the airbag inflation port, and then fix the steel ring brace using support connection bolts and ring brace connection lugs;

[0062] Step S3: During the backfilling process, remove the inner support components layer by layer from bottom to top. For each layer of the inner support component removed, backfill a section of the foundation pit with a preset height until backfilled to the ground level;

[0063] Step S4: Pull out the annular steel plate upward to complete the full-recovery operation of the support system;

[0064] Among them, the spacing between adjacent inner support components is consistent, and the preset height does not exceed the spacing between adjacent inner support components;

[0065] It should be noted that as Figures 11 to 13 shown, the ring-shaped steel plate 1 is assembled into a whole on-site through the vertical connecting plate 8 of the standard section of the shaft support, the circumferential connecting plate 9 of the standard section of the shaft support, and the connecting plate fixing bolt 10. The strengthening lock collar beam 18 is installed at the top of the ring-shaped steel plate 1, and the ring-shaped steel plate 1 is sunk by using a vibrating device. During this process, bentonite thixotropic slurry 19 can be injected through the longitudinal grouting pipe 6 and the circumferential grouting pipe 7 to reduce the sinking resistance; 3-4 standard sections can be assembled vertically for the ring-shaped steel plate 1 each time. After the overall sinking, continue to assemble on it until the design depth is reached. Then, excavate a standard section depth in the well, install the quick-disassembly support 5 by using the bracket buckle 11 of the corbel, install the steel ring strut 2 and the inflatable airbag 3 on the quick-disassembly support 5 to form a rigid-flexible collaborative internal support structure. Then, inflate the inflatable airbag 3. When the data displayed by the air pressure monitoring device reaches the design requirements, seal the airbag inflation port 14 to complete the pre-tightening of the internal support, and fix the support connection bolt 13 to lock the internal support. When the construction of two layers of supports in a standard section is completed, install the vertical connecting member 4 through the vertical connecting ear plate 16 and the vertical connecting bolt 17;

[0066] After the construction of a standard section is completed, continue to excavate the depth of the next standard section, and cycle the above steps until the design base is excavated to complete the shaft construction. After the operation in the shaft is completed, remove the vertical connecting member 4 of the bottommost standard section, open the airbag inflation port 14, discharge the gas in the inflatable airbag 3, open the support connection bolt 13, remove the steel ring strut 2, then backfill the depth range of the bottommost standard section with qualified soil and compact it, and then remove the previous section, layer by layer in a cycle, until backfilled to the ground. Finally, use mechanical equipment to pull out and remove the ring-shaped steel plate 1 to realize the full recovery of the shaft structure. During this process, bentonite thixotropic slurry 19 can be injected through the longitudinal grouting pipe 6 and the circumferential grouting pipe 7 to reduce the pulling resistance;

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fully recyclable steel composite structure shaft support system, characterized in that: It comprises an annular steel plate and a plurality of inner support assemblies mounted on the annular steel plate, wherein the annular steel plate is sunk before the shaft is excavated and is pulled out after the backfilling is completed; Among them, multiple inner support assemblies are distributed at intervals along the vertical direction, and the inner support assembly includes a steel ring support installed on the annular steel plate. There is a gap between the steel ring support and the annular steel plate, and an inflatable airbag is arranged in the gap to pre-tighten the steel ring support. The sides of two adjacent steel ring supports away from the annular steel plate are connected by vertical connecting parts, and the inner support assemblies are increased layer by layer during the foundation pit excavation process and are recovered layer by layer during the backfilling process.

2. A fully recyclable steel composite structure shaft support system according to claim 1, characterized in that: A longitudinal grouting pipe and an annular grouting pipe are arranged on both sides of the annular steel plate, and the longitudinal grouting pipe and the annular grouting pipe extend in directions perpendicular to each other.

3. The fully recyclable steel composite structure shaft support system according to claim 1 is characterized in that: The annular steel plate is formed by splicing a plurality of sub-plate segments, and a locking ring beam is arranged on the top of the annular steel plate.

4. The fully recyclable steel composite structure shaft support system according to claim 1 is characterized in that: The annular steel plate is also provided with a quick-release bracket for fixing the steel ring support, and the quick-release bracket is connected to the annular steel plate via a connecting buckle arranged on the inner side of the annular steel plate.

5. The fully recyclable steel composite structure shaft support system according to claim 3 is characterized in that: Adjacent sub-plate segments in the horizontal direction are connected together by vertical connecting plates, and adjacent sub-plate segments in the vertical direction are connected together by annular connecting plates. Both the vertical connecting plates and the annular connecting plates are mounted on the sub-plate segments by fixing bolts.

6. A fully-recoverable steel composite structure shaft support method, based on the fully-recoverable steel composite structure shaft support system according to any one of claims 1 to 5, characterized in that: The steps include: Step S1, sinking the annular steel plate by a vibration device, and in the process of sinking the annular steel plate, adding sub-plate segments to the annular steel plate layer by layer in the vertical direction; Step S2, during the shaft excavation process, the foundation pit is excavated from top to bottom, and a layer of inner support components is installed every time a foundation pit of a preset height is excavated until the designed support bottom surface is excavated; Step S3, during the backfilling process, the inner support components are removed layer by layer from bottom to top, and each time a layer of the inner support components is removed, a foundation pit of a preset height is backfilled until it reaches the ground; Step S4, pulling out the annular steel plate upwards to complete the full recovery operation of the support system; The spacing between the inner support components of two adjacent layers is consistent, and the preset height does not exceed the spacing between the inner support components of two adjacent layers.

7. A method for supporting a shaft with a fully recyclable steel composite structure according to claim 6, characterized in that: In step S1, it also includes: The sub-plate segments are assembled into an integrated annular steel plate by using vertical connecting plates, annular connecting plates and fixing bolts, and a locking ring beam is installed on the top of the annular steel plate.

8. A method for supporting a shaft with a fully recyclable steel composite structure according to claim 7, characterized in that: In step S1, it also includes: During the sinking process of the annular steel plate, bentonite thixotropic slurry is injected into the foundation pit through longitudinal grouting pipes and annular grouting pipes along both sides of the annular steel plate to reduce the sinking resistance.

9. A method for supporting a shaft with a fully recyclable steel composite structure according to claim 7, characterized in that: In step S2, a layer of inner support components is installed every time a foundation pit of a preset height is excavated, including: The quick-release bracket is installed using the bracket buckle on the inner side of the annular steel plate, and then the steel ring support and the inflatable airbag are installed on the quick-release bracket.

10. A method for supporting a shaft with a fully recyclable steel composite structure according to claim 9, characterized in that: In step S2, it also includes: The inflatable airbag is inflated, and when the air pressure reaches the preset pressure, the airbag inflation port is closed, and then the steel ring support is fixed by the support connecting bolts and the ring support connecting ear plates.

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