CN104234447B - Deep foundation ditch tool-type hangs stair - Google Patents

Abstract

The invention discloses a tool-type hanging staircase for deep foundation pits, which comprises a ladder frame, a ladder frame support and a staircase. Each set of ladder frame unit includes 4 columns, the cross section of the ladder frame unit is rectangular, the upper end of the column is vertically fixedly connected with the steel beam above it, and the lower end of the column extends vertically to the bottom of the foundation pit; the ladder frame support and the foundation pit enclosure The structure is fixedly connected. The ladder support includes 2 or 4 steel beams, and the steel beams are fixed on the upper surface of the crown beam of the enclosure structure; the stairs are installed between two sets of ladder units in sequence from top to bottom. A rest platform is set at the corner of the room, and the rest platform is fixed in the inner space of the ladder frame unit. The staircase of the present invention has the feature of hanging, the staircase is installed from top to bottom, and can be closely integrated with the process of foundation pit engineering; it is convenient for construction personnel to pass, has high safety performance, fast disassembly and assembly speed, and high turnover rate.

Description

Tool type hanging stairs for deep foundation pit

technical field

The invention belongs to the technical field of construction engineering, and relates to a staircase used for safety protection at a construction site, in particular to a tool-type staircase suspended in a deep foundation pit.

Background technique

A foundation pit is a soil pit excavated at the foundation design position according to the base elevation and foundation plane size. Building foundation pit refers to the space below the ground excavated for the construction of the foundation and basement of buildings (including structures). The foundation pit is a temporary project, and its function is to provide a space so that the foundation masonry can be carried out according to the position specified by the design. According to the Ministry of Construction's Jianzhi No. 200987 document on the issuance of the "Notice on the Safety Management Measures for Sub-projects with Higher Risks", the general deep foundation pit refers to the excavation depth exceeding 5 meters (including 5 meters) or the basement of more than three floors (including three floors), or projects whose depth does not exceed 5 meters, but the geological conditions, surrounding environment and underground pipelines are particularly complicated.

Foundation pit engineering mainly includes the design and construction of foundation pit support system and earthwork excavation, which is a highly comprehensive system engineering. Excavation engineering requires close cooperation between geotechnical and structural engineering technicians. The foundation pit project is to excavate an underground space from the ground down. A vertical retaining enclosure structure is generally set around the deep foundation pit. The enclosure structure is generally a plate (pile) wall structure with a certain insertion depth under the foundation of the excavation surface. . The slab (pile) wall mainly includes cantilever type, single support type and multi-support type. In order to reduce the deformation of the enclosure structure and control the bending moment of the wall, it is necessary to set up supporting structures around the foundation pit. As for the types of deep foundation pit enclosure structures, there are more types of plate-column type, column type, gravity retaining wall, combined type, soil anchor, reverse construction method, caisson and other types that are widely used in our country.

In the foundation pit construction, the horseway is a temporary scaffold for entering the foundation pit or going upstairs. The bridleway is a one-time installation and dismantling structure, that is, it will be used after the erection. As the structure construction progresses, when the position of the bridleway hinders the structural construction, it will be completely dismantled at one time, and another one will be erected at the completed part of the structure. In the past, scaffolding was often used to build sidewalks in deep foundation pits. Since this kind of sidewalk is a general temporary facility and easy to erect, there are many safety hazards, which can easily cause accidents of people falling from heights. Furthermore, most of the scaffolding needs to be erected upwards from the base, which is inconsistent with the excavation process of the deep foundation pit. Often the earthwork cannot be erected in a timely and orderly manner during the excavation process. The construction workers mainly use motor vehicles to unearth the horses and go up and down the foundation pit. There are many safety hazards such as mixed traffic of people and vehicles, inadequate protection, etc. At the same time, it is difficult to meet the requirements of safe and civilized construction of the project, and it is also not conducive to the rapid organization and efficient implementation of construction.

As the pace of subway construction and urban underground space development continues to accelerate, deep foundation pit projects are developing in the direction of "dense, deep, and large". To ensure the safety of construction personnel, it is necessary to make safe and standardized access stairs. At present, the tools for going up and down the foundation pit on the construction site are mostly steel ladders. This simple and easy steel ladder all is welded by materials such as steel pipe, angle steel substantially, has many defectives. The defects of this kind of pedestrian walkway are mainly as follows: first, the disassembly process is cumbersome, labor-intensive and labor-intensive; second, there is no protective structure around, and the safety performance is low; third, it is not conducive to turnover, low reuse rate, and large waste of materials.

Aiming at the above-mentioned technical defects of existing deep foundation pit stairs, currently, there are not many published patents, and the retrieved existing patents are now described.

Patent document CN201962965U discloses a cage ladder for deep foundation pit construction, which is composed of multiple cage ladder sections with the same structure and size assembled sequentially from bottom to top. The two adjacent cage ladder sections are fastened and connected by fastening connectors; the cage ladder sections include a cube-shaped peripheral frame, protective structures arranged around the peripheral frame and escalators installed in the peripheral frame; multiple cages The escalators installed inside the ladder section are connected from top to bottom to form a zigzag-shaped upper and lower passages for construction personnel to walk during the construction of deep foundation pits. correspond. The patent has the advantages of convenient processing and assembling, and adjustable assembling height, which can solve practical problems such as the inconvenience of personnel going up and down the foundation pit, the large base area occupied by the escalator, and the inconvenience of moving.

Patent document CN202731730U discloses an assembled safety staircase built in the foundation pit, including two side brackets, more than ten stair steps connecting the two side brackets and handrail bars on both sides; each side bracket consists of a front stair beam and a rear stair beam 1, the upper horizontal connecting rod and the lower horizontal connecting rod form a parallelogram frame; the extended ends of the upper and lower horizontal connecting rods are respectively bolted to the upper edge of the foundation pit and the concrete foundation base in the foundation pit; the front stair beam and the rear stair beam More than ten jacks are evenly distributed on the inner side of the stair step, which cooperate with the bolts at the four corners of the bottom surface of the stair step; the stair step is installed in place through the plugging of the bolt and the jack. An upper column is vertically arranged at the joint between the upper horizontal connecting rod and the top of the rear stair beam on each side, and a lower column is vertically provided at the joint between the lower horizontal connecting rod and the bottom end of the front stair beam, and the two are connected by a handrail. The advantages of this patent are flexible arrangement and stable structure.

Patent document CN203213639U discloses a combined staircase for foundation pits, including a plurality of connecting units, each connecting unit includes a pair of bottom beams parallel to each other, at least two bottom stops, and the bottom stops are respectively arranged between the two bottom beams between them and firmly connected with the bottom beam, at least four vertical bars, each two vertical bars as a group, respectively set longitudinally on the two bottom beams, at least two horizontal bars, and the two horizontal bars are respectively set on the top of the two vertical bars And it is firmly connected with the vertical bar; it also includes a number of longitudinal connecting sleeves and horizontal bar connecting pieces; between each connecting unit, the bottom beam and horizontal bar of each connecting unit are connected through the longitudinal connecting sleeve and the horizontal bar connecting piece to realize the longitudinal connection of each connecting unit. connect. The patent has the beneficial effects of being able to be installed on site, saving time and effort, all components can be dismantled, and can be installed and used repeatedly.

Patent document CN203755717U discloses a deep foundation pit assembly type upper and lower walkways, including left and right fixed frames formed by four square columns erected at the four apex positions of the rectangle respectively, the left fixed frame and the right fixed frame There are multi-layer stair platforms at intervals in the vertical direction, and the left and right fixed frame stair platforms are staggered in height. One side of the stair platform and the upper stair platform on the opposite side of the fixed frame pass through an inclined The set stair step boards are connected, and the other side of the stair platform is connected with the stair platform of the next floor through the obliquely arranged stair step boards. The advantage of this patent is that it adopts an assembled structure, the assembly and disassembly process is simple, and it can be repeatedly disassembled and assembled for reuse.

It should be pointed out that although the stairs involved in the above-mentioned patents have improved the existing deep foundation pit stairs, the design of the stairs is still not reasonable enough to meet the traffic requirements of different construction areas or stages of deep foundation pit engineering; The installation is from bottom to top, which is inconsistent with the deep foundation pit earthwork excavation process, and cannot be completely combined with the foundation pit earthwork excavation, slope support and subsequent structural construction procedures. For this reason, it is necessary to design a kind of stairs that can be directly applied to the deep foundation pit in the construction process of open-cut underground space engineering, subway engineering or other underground engineering.

Contents of the invention

The object of the present invention is to provide a tool-type hanging staircase for deep foundation pits, which provides safety and convenience for construction personnel to pass, and makes it have the advantages of fast disassembly and assembly, high turnover rate, and good safety performance. What is important is that the tool-type hanging staircase of the present invention can be closely integrated with the excavation of foundation pit earthwork, slope support and subsequent structural construction procedures, and is suitable for excavation depths of 10-30m deep foundation pits.

For realizing above-mentioned purpose, the technical scheme that the present invention takes is:

A tool-type hanging staircase for a deep foundation pit, comprising a ladder frame installed in the foundation pit, a ladder frame support supporting the ladder frame, and a staircase installed in the inner space of the ladder frame, characterized in that the ladder frame support It is fixedly connected with the enclosure structure of the foundation pit, and the ladder frame support includes 2 or 4 steel beams, one or both ends of which are fixed on the upper surface of the crown beam of the enclosure structure; the ladder frame is composed of two sets of ladder frame units There is a gap for installing stairs between the two sets of ladder frame units. Each set of ladder frame units includes 4 columns. The cross section of the ladder frame unit is rectangular. Extend vertically to the bottom of the foundation pit; the stairs are installed sequentially in the space between two sets of ladder frame units from top to bottom, and a rest platform is set at the corner between adjacent stairs, and the rest platform is fixed in the inner space of the ladder frame unit .

The ladder support can include 4 identical steel beams and be installed on one side of the foundation pit. The steel beams are arranged parallel to each other and are perpendicular to the crown beam of the enclosure structure of the foundation pit. One end of the steel beam is connected to the crown beam of the enclosure structure. The upper surface of the steel beam is fixed by bolts and welding, and the free ends of the four steel beams are located above the foundation pit; several transverse connecting rods are arranged on the upper surface of the steel beams, and the horizontal connecting rods are arranged parallel to the horizontal direction and perpendicular to the steel beams , the transverse connecting rod and the steel beam are fixedly connected by bolts.

The ladder support can also include horizontal braces, braces and stiffeners; the horizontal braces are arranged on one side of the outer steel beam, and one end of the horizontal braces is embedded in the pre-embedded crown beam of the enclosure structure. Buried bolts are fixedly connected to the crown beam of the enclosure structure, the other end of the horizontal brace is bolted to a connecting plate, and the connecting plate is welded to the steel beam; the diagonal brace is arranged under the steel beam, and one end of the diagonal brace is embedded The pre-embedded bolts on the side of the crown beam of the enclosure structure are fixedly connected with the crown beam of the enclosure structure, the other end of the diagonal support is connected with the steel beam bolts through a backing plate, and the backing plate is welded to the steel beam; the stiffening ribs are welded on the steel beam free end.

The ladder frame support can also include 2 steel beams and be installed at the corner of the foundation pit, the steel beams are arranged parallel to each other, the angle between the steel beam and the corner side of the foundation pit is 45 degrees, and the two ends of each steel beam Both are fixed to the upper surface of the crown beam of the enclosure structure by bolts and welding; two sets of intersecting steel bars or small-sized steel bars are welded between the two steel beams, and the steel bars or small-sized steel bars are arranged on the outside of the ladder frame unit.

The ladder support can also include an oblique support; the oblique support is arranged below the steel beam, and one end of the oblique support is fixedly connected with the enclosing structure crown beam through the pre-embedded bolt embedded in the side of the enclosing structure crown beam, The other end of the oblique support is bolted to the steel beam through a backing plate, and the backing plate is welded to the steel beam.

The connection between the steel beam and the crown beam of the enclosure structure can be provided with a backing plate, the embedded bolts in the crown beam of the enclosure structure are connected with the steel beam through the backing plate, the upper surface of the backing plate is connected with the weld seam of the steel beam, and the backing plate The gap between the lower surface of the board and the upper surface of the crown beam of the enclosure structure is filled with grouting material.

The column and the steel beam can be fixedly connected by bolts, a connecting plate is arranged between the column and the steel beam, the bolt passes through the connecting plate to connect the column and the steel beam, and the upper surface of the connecting plate is connected to the weld seam of the steel beam.

The stairs may include a step plate, a step plate support plate and protective railings arranged on both sides of the step plate. With closed metal mesh.

The rest platform may include a frame, several load-bearing parts and platform boards, the corners of the frame are connected with the columns forming the ladder frame unit, the load-bearing parts are welded in parallel inside the frame, and the platform board is laid on the side where the frame and the load-bearing parts are located. On the plane; the side of the rest platform is provided with protective railings, and a closed metal mesh is arranged on the protective railings.

The corner of the rest platform can be fixedly connected with the column through the channel steel, the waist height of the channel steel is welded with the column, the upper surface of the upper leg width of the channel steel is installed with a rest platform, and the lower leg width of the channel steel is arranged under the channel steel One side of the angle iron is bolted, and the other side of the angle iron is welded to the column.

Compared with existing stairs suitable for deep foundation pits, the present invention has the following beneficial effects:

(1) With the continuous advancement of green construction and safe and civilized construction, standardizing and tooling safety protection devices is an effective way to achieve sustainable development of the construction industry. Obviously, the tool-type hanging staircase for deep foundation pits provided by the present invention conforms to this development concept, and can be directly applied to the construction process of open-cut underground space projects, subway projects or other underground projects, especially suitable for excavation depths of 10~ 30m deep foundation pit.

(2) The staircase for deep foundation pit of the present invention has the characteristics of hanging. During the excavation of the foundation pit and the construction of the enclosure structure, the staircase components are installed from top to bottom according to the actual situation; during the construction of the underground main structure, it can be Choose to disassemble the stair components from bottom to top; for the part where the distance between the bottom of the stairs and the bottom of the foundation pit is less than the height of the stair components, you can use fastener-type scaffolding pipes to build temporary horse paths as a supplement, which can fully meet the traffic needs of different construction stages of deep foundation pit projects . Therefore, the present invention can be fully integrated with the earthwork excavation of foundation pit, side slope support and subsequent structure construction procedures.

(3) In the tool-type hanging staircase for deep foundation pits of the present invention, steel beams are used as the main force-bearing components, and there are different installation methods, such as four steel beams fixed on the same side of the foundation pit, or two steel beams The beam is fixed at the corner of the foundation pit. Therefore, the present invention can select different steel girder installation methods according to specific construction needs, and has optionality. When the cross-sectional size of the crown beam of the foundation pit is difficult to meet the length requirement of the steel beam force arm, the force arm can be lengthened and a counterweight can be added to meet the force requirement.

(4) In the tool-type hanging staircase for deep foundation pit of the present invention, the staircase mainly exists in the form of standard joints, which is convenient to ensure the accuracy of the size and the position of the bolt holes during manufacturing. During the on-site installation process, there is no need for workers to think or make creative changes to ensure smooth installation, save time and effort, and increase the penetration rate.

(5) The tool-type hanging staircase for deep foundation pits of the present invention can provide safety and convenience for construction personnel to pass, and has the advantages of fast disassembly and assembly, high turnover rate, and good safety performance.

Description of drawings

Fig. 1 is a plan view of the ladder support of the tool-type hanging stairs installed in the deep foundation pit on one side of the foundation pit.

FIG. 2 is a schematic cross-sectional view of FIG. 1 .

Fig. 3 is the plan view of the ladder support of the tool-type hanging staircase installed in the deep foundation pit at the transition place of the foundation pit.

FIG. 4 is a schematic cross-sectional view of FIG. 3 .

Fig. 5 is a connection diagram of the embedded bolt and the embedded steel plate.

Fig. 6 is a fixed connection diagram of the steel beam and the crown beam of the enclosure structure.

Fig. 7 is a connection diagram of stairs and a rest platform.

Figure 8 is a plan view of the rest platform.

FIG. 9 is a schematic cross-sectional view of FIG. 8 .

Fig. 10 is a connection relationship diagram between a rest platform and a column.

Figure 11 is a front elevation view of the staircase.

FIG. 12 is a side view of FIG. 11 .

Explanation of reference signs: 1. Upright column; 2. Steel beam; 3. Crown beam of enclosure structure; 4. Rest platform; 5. Transverse connecting rod; 6. Horizontal diagonal brace; 9. Steel bar or small section steel; 10. Embedded bolt; 11. Embedded steel plate; 12. Backing plate; 13. Grouting material; 14. Connecting plate; 15. Step plate; 16. Step plate support plate; 17. Protection Railing; 18. Frame; 19. Load-bearing parts; 20. Platform board; 21. Transition member; 22. Diagonal support; 23. Protective shed;

detailed description

With the continuous advancement of green construction and safe and civilized construction, implementing the national development strategy of strengthening energy conservation and emission reduction, building a resource-saving and environment-friendly society, and making safety protection devices standardized and tool-based is the key to achieving sustainable development of the construction industry effective way. In particular, the current pace of subway construction and urban underground space development is accelerating, and the safety problems brought about by deep foundation pit projects are becoming increasingly prominent. The existing pedestrian passages suitable for deep foundation pit engineering have low safety performance, and the disassembly and assembly process is cumbersome, and the reuse rate is low, especially it does not conform to the construction sequence of the foundation pit engineering.

In order to solve the above problems and adapt to the development requirements of standardized and tool-type construction safety protection devices, the present invention provides a tool-type hanging staircase for deep foundation pits. The structure of the tool-type hanging stairs for deep foundation pits is shown in Figure 1, Figure 2, Figure 3 and Figure 4, including ladder frames, ladder frame supports and stairs. Among them, the ladder frame is installed in the foundation pit to support the stairs for construction personnel; the ladder frame support is fixedly connected with the foundation pit to support and fix the ladder frame; the stairs are installed in the inner space of the ladder frame to facilitate construction People enter and leave the foundation pit. Also, as shown in FIGS. 11 and 12 , a protective shed 23 is installed above the ladder frame support.

Specifically, the ladder frame is composed of two sets of ladder frame units, and there is a gap for installing stairs between the two sets of ladder frame units. Each ladder frame unit includes four columns 1, the cross section of the ladder frame unit is rectangular, the upper end of the column 1 is vertically fixedly connected with the steel beam 2 above it, and the lower end of the column 1 extends vertically to the bottom of the foundation pit. As a preferred embodiment, the four uprights 1 can be four identical uprights 1, and the uprights 1 can be made of square steel. The material of the steel girder 2 needs to be selected according to the installation position and method of the steel girder 2, and I-beam or H-beam can be selected.

The ladder frame support is fixedly connected with the foundation pit enclosure structure, and the ladder frame support extends to the upper space of the foundation pit. According to the construction needs of the foundation pit project, the ladder support can be installed on the same side of the foundation pit or at the corner of the foundation pit. The ladder support includes 2 or 4 steel beams 2, and one or both ends of the steel beams 2 are fixed on the upper surface of the crown beam 3 of the enclosure structure.

If the ladder support is installed on the edge of the foundation pit, as shown in Figure 1 and Figure 2, the tool-type hanging staircase for deep foundation pits of the present invention adopts cantilevered installation. As a preferred embodiment, the ladder support includes 4 identical steel beams 2 and is installed on one side of the foundation pit. The steel beams 2 are arranged parallel to each other and are all perpendicular to the crown beam 3 of the enclosure structure of the foundation pit. The steel beams One end of 2 and the upper surface of crown beam 3 of the enclosure structure are fixed by bolts and welding, and the free ends of the four steel beams 2 are located above the foundation pit. In particular, the free ends of the four steel beams 2 are on the same straight line, and the straight line is parallel to the crown beam 3 of the enclosure structure that is fixedly connected to the steel beams 2 . In this case, the steel beam 2 can be I-beam, the installation distance between the steel beam 2 on both sides and the adjacent steel beam 2 can be 900mm, and the installation distance between the two steel beams 2 in the middle It can be 2170mm.

Further, the ladder support also includes transverse connecting rods 5 , horizontal braces 6 and stiffeners 7 . In order to enhance the integrity of the entire ladder frame support, a transverse connecting rod 5 is arranged on the upper surface of the steel beam 2 . As a preferred embodiment, there can be three transverse connecting rods 5 arranged on the steel beam 2, and the transverse connecting rods 5 can be selected from angle steel. Three transverse connecting rods 5 are arranged parallel to each other along the horizontal direction and perpendicular to the steel beam 2, wherein two transverse connecting rods 5 are installed above the connection position between the steel beam 2 and the column 1, and the other transverse connecting rod 5 is installed on the surrounding The top of the protective structure crown beam 3. The transverse connecting rod 5 is fixedly connected with the steel beam 2 through bolts. As a further preference, the installation distance between the transverse connecting rod 5 above the connection position of the steel beam 2 and the column 1 and the transverse connecting rod 5 in the middle position can be 2130mm, and the transverse connecting rod 5 in the middle position and the transverse connecting rod 5 installed in the surrounding The installation spacing between the transverse connecting rods 5 above the crown beam 3 of the protective structure can be 1550mm.

In order to improve the safety factor and increase the constraints on the cantilevered stairs, a horizontal diagonal brace 6 is set on one side of the outer steel beam, and one end of the horizontal diagonal brace 6 is pre-embedded in the crown beam 3 of the enclosure structure. It is fixedly connected with the crown beam 3 of the enclosure structure, and the other end of the horizontal brace 6 is connected with a connecting plate 8 by bolts, and the connecting plate 8 is welded with the steel beam 2 . In addition, diagonal supports 22 are provided under the steel beams 2 . As a preferred embodiment, one diagonal support 22 may be provided under each steel beam 2 . One end of the diagonal support 22 is fixedly connected to the inner surface of the enclosure structure crown beam 3 (the side facing the foundation pit) through the embedded bolt 10; the other end of the diagonal support 22 is connected to the steel beam 2 through a backing plate 12, and the diagonal support 22 It is bolted to the backing plate 12, and the backing plate 12 is welded to the steel beam 2. It should be noted that the purpose of providing the backing plate 12 between the diagonal support 22 and the steel beam 2 is to ensure a more reliable connection between the diagonal support 22 and the steel beam 2 . As a preferred embodiment, the angle between the oblique support 22 and the inner surface of the enclosure structure crown beam 3 is 45 degrees, and the angle between the oblique support 22 and the steel beam 2 is also 45 degrees, and the oblique support 22 can be made of square steel . In addition, since the steel beam 2 is the main load structure of the tool-type hanging staircase for deep foundation pits of the present invention, in order to enhance the section stiffness of the stress point of the steel beam 2, the free end of the steel beam 2 is welded with stiffeners 7 .

If the ladder frame support is installed at the corner of the foundation pit, as shown in Figure 3 and Figure 4, the tool-type hanging staircase for deep foundation pits of the present invention adopts simply supported installation. As a preferred embodiment, the ladder support includes two steel beams 2 and is installed at the corner of the foundation pit, the two steel beams 2 are arranged in parallel, and the angle between the steel beams 2 and the corner side of the foundation pit is 45 degrees , both ends of each steel beam 2 are fixed to the upper surface of the enclosure structure crown beam 3 by bolts and welding. In this case, the steel beam 2 can be H-shaped steel, and the steel beam 2 near the corner of the foundation pit is shorter. The installation distance between two steel beams can be 2280mm, the width of each ladder frame unit is 900mm, and the installation distance between two adjacent ladder frame units can be 2170mm.

In order to enhance the overall stability between two adjacent steel beams and improve the safety factor, as a preference, two sets of intersecting steel bars or small-sized steel bars 9, steel bars or small-sized steel bars are welded between the two steel beams 2 9 is arranged on the outside of the ladder frame unit, that is, the steel bar or small section steel 9 is between the corner edge of the ladder frame unit and the foundation pit. In addition, diagonal supports 22 are provided under the steel beams 2 . As a preferred embodiment, one diagonal support 22 may be provided under each steel beam 2 . One end of the diagonal support 22 is fixedly connected to the inner surface of the enclosure structure crown beam 3 (the side facing the foundation pit) through the embedded bolt 10; the other end of the diagonal support 22 is connected to the steel beam 2 through a backing plate 12, and the diagonal support 22 It is bolted to the backing plate 12, and the backing plate 12 is welded to the steel beam 2. It should be noted that the purpose of providing the backing plate 12 between the diagonal support 22 and the steel beam 2 is to ensure a more reliable connection between the diagonal support 22 and the steel beam 2 . As a preferred embodiment, the angle between the oblique support 22 and the inner surface of the enclosure structure crown beam 3 is 45 degrees, and the angle between the oblique support 22 and the steel beam 2 is also 45 degrees, and the oblique support 22 can be made of square steel .

It should be noted that no matter which installation method is used for the tool-type hanging stairs for deep foundation pits, in order to improve the firmness of the connection between the steel beam 2 and the crown beam 3 of the enclosure structure, the gap between the steel beam 2 and the crown beam 3 of the enclosure structure Not only bolted but also welded. In order to achieve this purpose, as shown in Figure 5 and Figure 6, the inside of the enclosure structure crown beam 3 is provided with embedded bolts 10 and embedded steel plates 11, and the base of the embedded bolts 10 is arranged on the base of the embedded steel plates 11. upper and connected by plug welding. As a further optimization of the technical solution of the present invention, in order to increase the force bearing area of the fulcrum of the steel beam 2, ensure that the steel beam 2 is evenly stressed on the surface of the enclosure structure crown beam 3, the distance between the steel beam 2 and the enclosure structure crown beam 3 A backing plate 12 is also provided at the joint, and the pre-embedded bolts 10 are connected to the steel beam 2 through the backing plate 12, the upper surface of the backing plate 12 is welded to the steel beam 2, and the lower surface of the backing plate 12 is connected to the crown beam 3 of the enclosure structure. Grouting material 13 is filled in the gap between the upper surfaces.

In order to further improve the reliability of the connection between the column 1 and the steel beam 2, on the basis that the column 1 and the steel beam 2 are fixedly connected by bolts, a connecting plate 14 is arranged between the column 1 and the steel beam 2, and the bolt passes through the connection The plate 14 connects the column 1 and the steel beam 2 , and the upper surface of the connecting plate 14 is welded to the steel beam 2 .

Further, the stairs are sequentially installed in the space between two sets of ladder frame units from top to bottom, and rest platforms 4 are arranged at the corners between adjacent stairs, and the rest platforms 4 are fixed in the inner space of the ladder frame units. Specifically, as shown in Figure 7, the stairs include a tread plate 15, a tread plate support plate 16 and a protective railing 17, wherein the tread plate 15 is welded on the tread plate support plate 16, and the end of the tread plate support plate 16 Welded with column 1, protective railing 17 is arranged on step plate 15 both sides. In particular, the protective railing 17 is provided with a closed metal mesh, so as to improve the safety performance of the construction personnel when passing the stairs. Preferably as an embodiment, the protective railing 17 can be welded with square steel for use; the step plate support plate 16 can be a C-shaped steel, and the selection specification of the C-shaped steel is height 160mm, middle leg side length 60mm; between the step plate 15 and the rest platform 4 A 20mm thick steel plate can also be set as the transition member 21 at the junction of the steel plate, and the side of the steel plate is welded with the column 1; the tread plate 15 can be a 3mm thick checkered steel plate.

In the tool-type hanging staircase for deep foundation pit of the present invention, the staircase mainly exists in the form of standard joints, and it is convenient to ensure the accuracy of the size and the position of the bolt holes during manufacturing. During the on-site installation process, there is no need for workers to think or make creative changes to ensure smooth installation, save time and effort, and increase the penetration rate.

In the tool-type hanging staircase for deep foundation pits of the present invention, as shown in FIG. 8 and FIG. 9 , the rest platform 4 includes a frame 18 , several load-bearing parts 19 and a platform board 20 . Wherein, the corners of the frame 18 are connected with the columns 1 constituting the ladder frame unit, the load-bearing parts 19 are welded in parallel inside the frame 18, and the platform board 20 is laid on the plane where the frame 18 and the load-bearing parts 19 are located. The side of the rest platform 4 is provided with protective railings 17, and the protective railings 17 are provided with closed metal meshes. Preferably as embodiment, frame 18 is made of channel steel, and the width of frame 18 is 1000mm, and the length of frame 18 is 2130mm; Setting, the load-bearing member 19 is made of angle steel; the platform plate 20 is a 3mm thick checkered steel plate, there are 6 pieces in total, which are laid on the plane where the frame 18 and the load-bearing member 19 are located in sequence.

As a further optimization of the technical solution of the present invention, as shown in Figure 10, the corner of the rest platform 4 is fixedly connected with the column 1 through the channel steel, the waist height of the channel steel is welded with the column 1, and the upper leg width of the channel steel is fixed. The rest platform 4 is installed on the surface, the lower leg width of the channel steel is connected with one side of the angle iron arranged under the channel steel by bolts, and the other side of the angle iron is welded with the column 1 .

It should be noted that when the cross-sectional dimension of the crown beam 3 of the enclosure structure of the foundation pit is difficult to meet the length requirement of the force arm of the steel beam 2, the force arm can be lengthened and a counterweight can be added to meet the force requirement.

As can be seen from the above, the biggest feature of the staircase for deep foundation pits of the present invention is that it is suspended, and the staircase components are installed from top to bottom according to the actual situation of construction. During the construction of the main underground structure, you can choose to disassemble the stair components from bottom to top; as shown in Figure 11 and Figure 12, for the part where the distance from the bottom of the stairs to the bottom of the foundation pit is less than the height of the stair components, you can use fastener-type scaffolding pipes A temporary horse track 24 is set up as a supplement, which can fully meet the traffic needs of different construction stages of the deep foundation pit project. Therefore, the present invention can be closely combined with foundation pit earthwork excavation, side slope support and follow-up structural construction procedures, and can be directly applied to open-cut underground space engineering, subway engineering or other underground engineering construction processes, and is especially suitable for excavation Dig the foundation pit to a depth of 10-30m.

Here is an actual construction example.

Taking the Wukesong underground parking garage project as an example, the specific implementation of the tool-type hanging steel stairs for deep foundation pits is described. The specific implementation is mainly reflected in three aspects of installation, use and disassembly.

Wukesong underground parking garage is a typical underground space project. The main structure is an underground three-story reinforced concrete frame structure. The foundation pit of the parking garage is 252m long from east to west and 287m long from north to south. The foundation pit is about 21.45m deep.

Restricted by the surrounding environment and site conditions, the excavation and support of the foundation pit can only be carried out from south to north, and the excavation road for motor vehicles is set on the north side of the foundation pit; on-site office and workers' living areas are arranged on the south and west sides of the foundation pit , in order to ensure the safety of the construction workers going up and down the foundation pit and meet the needs of the construction organization, according to the construction progress, 3 steel stairs were installed on the south side of the foundation pit first, and 2 steel stairs were installed on the north side of the foundation pit following the end of the earthwork.

The installation process of a single steel staircase is the same: pre-planning (setting position and stair hanging method); entrusted processing (processing of embedded parts first; installation of embedded parts; installation of steel beam 2 (installation of first run stairs, platforms and head guards) ); along with the excavation of foundation pit earthwork, the stair standard section (including the temporary curb at the bottom of the staircase) shall be installed circularly from top to bottom; the foundation pit shall be excavated to the base, and the stair standard section shall be dismantled circularly from bottom to top along with the construction of the main structure; Component turnover; demolition of the upper structure of the stairs and steel beams 2.

The present invention has been further described above in conjunction with the embodiments, but the present invention is not limited to the above-mentioned embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the gist of the present invention. kind of change.

Claims (10)

1. a deep foundation ditch tool-type hangs stair, comprise the ladder be arranged in foundation ditch, support the ladder bearing of ladder and be arranged on the stair of ladder inner space, it is characterized in that, described ladder bearing is fixedly connected with foundation pit enclosure structure, ladder bearing comprises 2 or 4 girder steels, and the one or both ends of girder steel are fixed on the upper surface of space enclosing structure Guan Liang; Described ladder is made up of two groups of ladder unit, be provided with the gap of installing stair between two groups of ladder unit, often organize ladder unit and comprise 4 columns, the cross section of ladder unit is rectangular, the upper end of column is fixedly connected with the girder steel above it is vertical, and foundation ditch bottom surface is vertically stretched in the lower end of column; Described stair are arranged in the space between two groups of ladder unit from top to bottom successively, and the corner between adjacent stair arranges half space, and half space is fixed on the inner space of ladder unit.

2. deep foundation ditch tool-type according to claim 1 hangs stair, it is characterized in that, described ladder bearing comprises 4 identical girder steels and is arranged on foundation ditch on one side, girder steel is arranged in parallel and all mutually vertical with the space enclosing structure Guan Liang of foundation ditch, one end of girder steel and the upper surface of space enclosing structure Guan Liang are by bolt and be welded and fixed, and the free end of 4 girder steels is positioned at the top of foundation ditch; The upper surface of described girder steel arranges several lateral connection bars, and lateral connection bar be arranged in parallel and mutually vertical with girder steel in the horizontal direction, and lateral connection bar and girder steel are bolted to connection.

3. deep foundation ditch tool-type according to claim 2 hangs stair, it is characterized in that, described ladder bearing also comprises horizontal diagonal brace, bearing diagonal and floor of putting more energy into; Described horizontal diagonal brace is arranged on the side of outside girder steel, and one end of horizontal diagonal brace is fixedly connected with space enclosing structure Guan Liang by the pre-embedded bolt being embedded in space enclosing structure Guan Liang, and the other end of horizontal diagonal brace is connected with a plate bolt, and junction plate welds with girder steel; Described bearing diagonal is arranged on the below of girder steel, and one end of bearing diagonal is fixedly connected with space enclosing structure Guan Liang by the pre-embedded bolt being embedded in space enclosing structure hat beam sides, and the other end of bearing diagonal is connected with girder steel bolt by a backing plate, and backing plate welds with girder steel; Described floor of putting more energy into is welded on the free end of girder steel.

4. deep foundation ditch tool-type according to claim 1 hangs stair, it is characterized in that, described ladder bearing comprises 2 girder steels and is arranged on the rotation angle position of foundation ditch, girder steel is arranged in parallel, the angle on the corner limit of girder steel and foundation ditch is 45 degree, the two ends of each girder steel all with the upper surface of space enclosing structure Guan Liang by bolt be welded and fixed; Weld 2 groups of cross one another reinforcing bars or small size shaped steel between described 2 girder steels, reinforcing bar or small size shaped steel are arranged on the outside of ladder unit.

5. deep foundation ditch tool-type according to claim 4 hangs stair, it is characterized in that, described ladder bearing also comprises bearing diagonal; Described bearing diagonal is arranged on the below of girder steel, and one end of bearing diagonal is fixedly connected with space enclosing structure Guan Liang by the pre-embedded bolt being embedded in space enclosing structure hat beam sides, and the other end of bearing diagonal is connected with girder steel bolt by a backing plate, and backing plate welds with girder steel.

6. the deep foundation ditch tool-type according to claim 2 or 4 hangs stair, it is characterized in that, the junction of described girder steel and space enclosing structure Guan Liang is provided with backing plate, pre-embedded bolt in space enclosing structure hat beam is connected with girder steel by backing plate, the upper surface of backing plate and girder steel solder design, be filled with grouting material in the gap between the soffit of backing plate and the upper surface of space enclosing structure Guan Liang.

7. deep foundation ditch tool-type according to claim 1 hangs stair, it is characterized in that, described column and girder steel are bolted to connection, between column and girder steel, be provided with junction plate, bolt connects column and girder steel through junction plate, the upper surface of junction plate and girder steel solder design.

8. deep foundation ditch tool-type according to claim 1 hangs stair, it is characterized in that, described stair comprise step plate, step plate gripper shoe and are arranged on the guard rail of step plate both sides, step plate is welded in step plate gripper shoe, the end of step plate gripper shoe is welded with column, described guard rail is provided with closed metal net.

9. deep foundation ditch tool-type according to claim 1 hangs stair, it is characterized in that, described half space comprises frame, several supporting parts and landing slab, the corner of described frame is connected with the column forming ladder unit, supporting part is welded on the inside of frame in parallel, and landing slab is laid in the plane at frame and supporting part place; The side of described half space arranges guard rail, guard rail is provided with closed metal net.

10. deep foundation ditch tool-type according to claim 9 hangs stair, it is characterized in that, the corner of described half space is fixedly connected with column by channel-section steel, the waist height portion of channel-section steel welds with column, the upper leg wide portion upper surface of channel-section steel installs half space, the wide portion of lower leg of channel-section steel is connected with one side bolt of the angle bar be arranged on below channel-section steel, and the another side of angle bar welds with column.