CN109958134B

CN109958134B - Suspension type deep basal pit stairs up and down

Info

Publication number: CN109958134B
Application number: CN201811380067.7A
Authority: CN
Inventors: 周家炜; 王博; 毕欣
Original assignee: China Construction Seventh Engineering Division Corp Ltd
Current assignee: China Construction Seventh Engineering Division Corp Ltd
Priority date: 2018-11-20
Filing date: 2018-11-20
Publication date: 2021-07-27
Anticipated expiration: 2038-11-20
Also published as: CN112854233A; CN109958134A

Abstract

The invention relates to a suspended type deep foundation pit stair ascending and descending, which comprises a plurality of first footpaths, a plurality of second footpaths, a telescopic supporting part and a plurality of suspended parts. The telescopic supporting part comprises a plurality of telescopic rods, the first step is respectively installed between two telescopic rods which are arranged on the same side and have different axes, the second step is respectively installed between two telescopic rods on different sides, and the first step and the second step are rotatably connected in a non-parallel mode. When pushing force or pulling force is applied to the telescopic rod, the first step way can change the first slope angle of the first step way in a mode of rotating around the second step way; and/or the second footpath can change the second slope angle of the second footpath in a mode of rotating around the first footpath; thereby stair can install in the inner space of deep basal pit through the mode of folding or expanding according to the change of first slope angle and second slope angle up and down to make stair can let the staff descend the deep basal pit gradually or return the earth's surface gradually.

Description

Suspension type deep basal pit stairs up and down

Technical Field

The invention belongs to the technical field of constructional engineering, relates to a stair for construction and particularly relates to a stair for a suspension type deep foundation pit.

Background

With the continuous promotion of green construction and safe and civilized construction, the development strategy of the nation on strengthening energy conservation and emission reduction is implemented, a resource-saving society and an environment-friendly society are built, and the green and environment-friendly construction of building engineering is gradually popularized. A foundation pit (foundation pit) is a soil pit excavated at a foundation design position according to a foundation elevation and a foundation plane size. The building foundation pit refers to a space below the ground excavated for constructing a foundation and a basement of a building (including a structure). The foundation pit belongs to temporary engineering and has the function of providing a space for basic masonry operation to be carried out according to the designed specified position. According to the stipulation of 'notice of safety management method of project of partial item with high risk' from the ministry of construction and construction No. 200987, the general deep foundation pit refers to a project with excavation depth of more than 5m (including 5m) or more than three layers (including three layers) of basement, or with depth of less than 5m, but with complex geological conditions and particularly complex surrounding environment and underground pipelines.

In modern building engineering, underground structures can be used as functional areas for parking, equipment, civil air defense, transportation, shopping and the like. With the pace of subway construction, urban underground space and high-rise construction being accelerated, deep foundation pit engineering is developing towards the direction of 'dense, deep and large'. The construction of deep foundation pit engineering is realized step by step along with the excavation of earthwork layer by layer, and personnel and materials need to enter the underground layer by layer during construction. In the process of excavating the earth of the deep foundation pit from top to bottom and constructing the structure from bottom to top, a safe and convenient upper channel and a safe and convenient lower channel are required to be erected to meet the construction requirements. At present, the instrument of foundation ditch about the job site is mostly the steel cat ladder. The proposed steel ladder stand is mainly formed by welding steel pipes, angle steels and other materials. It mainly has the following defects: the assembly and disassembly process is complicated, labor-consuming and troublesome; no safety protection device is arranged; low repeated utilization rate, waste of materials and the like.

In view of the above mentioned drawbacks, the prior art of going up and down stairs (or going up and down channels) in deep foundation pits mainly includes the following patent documents.

For example, a tool type suspended up-down stairs for a deep foundation pit disclosed in chinese patent publication No. CN104234447B comprises a ladder frame, a ladder frame support, and up-down stairs, wherein the ladder frame is composed of two sets of ladder frame units, a gap for installing up-down stairs is provided between the two sets of ladder frame units, each set of ladder frame unit comprises 4 upright posts, the cross sections of the ladder frame units are rectangular, the upper ends of the upright posts are vertically and fixedly connected with steel beams above the upright posts, and the lower ends of the upright posts vertically extend to the bottom surface of the foundation pit; the ladder frame support is fixedly connected with the foundation pit support structure and comprises 2 or 4 steel beams, and the steel beams are fixed on the upper surface of the support structure crown beam; the stairs are sequentially arranged between the two groups of ladder frame units from top to bottom, rest platforms are arranged at corners between the adjacent stairs and are fixed in the inner space of the ladder frame units. The stair climbing device has the hanging characteristic, and the stair climbing device can be installed from top to bottom and can be completely and tightly combined with the process of foundation pit engineering; the constructor of being convenient for is current, and the security performance is high, and the dismouting is fast, and turnover rate is high.

For example, chinese patent publication No. CN106836851A discloses a deep foundation pit suspension type construction for going up and down stairs. The construction up-down stairs are positioned between two reinforced concrete horizontal supports and comprise a first up-down stair, a second up-down stair and a third up-down stair, and the first up-down stair, the second up-down stair and the third up-down stair are connected end to form a Z-shaped structure. The deep foundation pit suspension type construction stair ascending and descending provided by the invention utilizes the reinforced concrete horizontal support in deep foundation pit engineering to suspend the stair ascending and descending on the support, so that the installation environment for constructing the stair ascending and descending can be greatly expanded, and the service performance is improved; in addition, the stairs can be lengthened or dismantled section by section according to the progress of the engineering, the defect of large field change during the construction of the deep foundation pit is met, and the high-speed stair has good adaptability.

For example, a deep foundation pit fabricated walkway disclosed in publication No. CN203755717U includes: the left fixing frame and the right fixing frame are vertically formed by four square tube stand columns according to four vertex positions of a rectangle, a plurality of layers of up-down stair platforms are distributed in the vertical direction at intervals on the left fixing frame and the right fixing frame respectively, the up-down stair platforms on the left fixing frame and the up-down stair platforms on the right fixing frame are staggered at intervals in height, one side of each up-down stair platform is connected with the up-down stair platform on the upper layer of the fixing frame on the opposite side through an up-down stair step plate arranged in an inclined mode, and the other side of each up-down stair platform is connected with the up-down stair step plate arranged on the lower layer of the up-down stair platform through an inclined mode. The pedestrian passageway adopts an assembly type structure, the square-tube upright posts form a left fixing frame and a right fixing frame which are opposite, the stair step plates for going up and down stairs can be conveniently assembled between the two fixing frames, the assembling and disassembling process is simple, labor and trouble are saved, the stair step plates can be repeatedly assembled and disassembled for reuse, the material waste is small, and the practicability, the safety, the attractiveness and the material reutilization property of the pedestrian passageway for going up and down are enhanced.

For example, chinese patent publication No. CN106677558A discloses a construction method for a deep foundation pit assembled boarding stairway, which solves the problem that the boarding stairway is easy to install, disassemble and can be used in a turnover manner. The construction steps comprise the manufacture of a foundation member, embedding foundation bolts and shear keys, connecting a supporting member with the concrete foundation through the foundation bolts, and connecting upright columns and cross beams of the supporting member through bolts; the steel is installed up and down stairs, and the ladder beam is connected with the supporting member through bolts; the color steel shed protection component is installed, the ceiling supporting square steel pipe is welded with the supporting component upright post, and the ground is connected through the supporting and inserting square steel pipe. The deep foundation pit assembled type upstairs and downstairs for getting on and off people has the characteristics of adjustable erection height, turnover use and high safety, the support members are connected with the foundation, the steel upstairs and downstairs and the color steel ceiling protective members through bolts, the assembly and installation of the members are realized, the installation is convenient, the construction progress is accelerated, and the engineering cost is saved due to the turnover use of the deep foundation pit.

For example, a cage ladder for deep foundation pit construction disclosed in chinese patent publication No. CN201962965U is composed of a plurality of cage ladder sections with the same structure and size, which are sequentially assembled from bottom to top, the plurality of cage ladder sections are arranged on the same vertical line, and two adjacent cage ladder sections are fastened and connected by fastening and connecting members; the cage ladder section comprises a cubic peripheral framework, a protection structure arranged on the four sides of the peripheral framework and an escalator arranged in the peripheral framework; the escalators installed inside the cage ladder sections are communicated from top to bottom to form a zigzag upper and lower channel for workers to walk in the deep foundation pit construction process, and the vertical height of the zigzag upper and lower channel corresponds to the depth of the deep foundation pit to be constructed. The invention has reasonable structural design, convenient processing, manufacture and assembly, adjustable assembly height, high safety factor, economy and practicability, and can solve the practical problems of lower safety factor, inconvenience for people to get on and off the foundation pit, large occupied base area of the escalator, inconvenience for movement and the like of the existing deep foundation pit upper and lower channels.

For example, the china patent with publication number CN205296892U discloses a section stair and passageway up and down for deep foundation pit construction is current from top to bottom, relates to engineering and relates to engineering construction equipment field, and section stair and down includes the skeleton, and the skeleton is frame construction, and the top surface rear end of skeleton is provided with an upper platform, and the bottom surface front end of skeleton is provided with a platform, and one side of upper platform and lower platform all is provided with connecting portion, and the opposite side all is provided with current portion, and the one side that is close to connecting portion in the skeleton is provided with the stair section up and down of an slope. The ascending and descending channel is formed by stacking and assembling a plurality of sections of ascending and descending stairs up and down, and the lower platform of the section of ascending and descending stairs positioned above in two adjacent sections of ascending and descending stairs is mutually overlapped with the upper platform of the section of ascending and descending stairs positioned below. The invention has simple and convenient assembly and disassembly, beautiful structure and repeated use.

For example, a suspended combined construction platform for building exterior wall construction disclosed in chinese patent publication No. CN205116683U includes an upper ejector rod adjuster, a construction platform horizontal support steel pipe, a pedal support rod, a pedal, and a construction platform longitudinal support steel pipe, the suspended combined construction platform is installed outside an exterior wall sideline, the changed outside of the exterior wall is fixed with the tie bolt through a fastening bolt, the outside of the tie bolt is provided with a groove-shaped shoulder pole steel, and the outside of the groove-shaped shoulder pole steel is connected with a diagonal draw bar through a bolt. The invention has the beneficial effects that: compared with the prior art, the method has the advantages of fewer system parts, simplicity in installation, convenience in disassembly, improvement of installation efficiency, acceleration of construction speed and safety and reliability in construction and use. The invention can be processed and produced in batches in factories and repeatedly used for many times in one-time production, and can be constructed by matching machines such as tower cranes and the like during field installation, thereby realizing high-altitude direct installation without being lifted from the ground, and saving a large amount of labor force for field manual installation.

For example, chinese patent publication No. CN202954733U discloses a suspended type ascending and descending stair for being suspended outside a bridge side frame, which includes a step for climbing, and a hook perpendicular to the step and provided at a first end of the step for hooking and fixing the hook on the bridge side frame. The hanging type upstairs and downstairs are hung outside the bridge side frames by using the hooks, so that space under the bridge is not occupied when the bridge is overhauled or repaired, and the downstairs can conveniently pass through; and the novel suspended type up-and-down stairs are simple in structure, convenient to manufacture, install and disassemble, and capable of saving a large amount of manpower and material resources.

For example, chinese patent publication No. CN203222949U discloses a suspended indoor stairway. The invention directly hangs the tower plates of the stairs from the roof, saves the base frame of the stairs, saves a large amount of materials and processing workload, provides a brand new model and ensures that the indoor design has more free space. The adjacent upper pedal and the lower pedal are fixed and the distance is adjusted by bolts, the bolts extend to the roof and are fixed on expansion bolts of the roof, thus the installation of a pedal combination is completed, all tower plate combinations are installed according to the design modeling, and the assembly of going upstairs and downstairs is completed.

Through the investigation discovery to prior art, the stair that is the upper and lower deep basal pit at present is installed and not telescopic according to the degree of depth layer by layer of deep basal pit, exists following not enough like this: the depth of a foundation pit for building the deep foundation pit is constantly changed, and when the depth of the deep foundation pit cannot meet the requirement of installing one section of stairs up and down, the deep foundation pit needs to be compensated by an external packway.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a suspension type deep foundation pit stair ascending and descending, which comprises: the first footpaths and the second footpaths form a plurality of footpath units for providing channels for workers; a telescopic support defining a working space for the upstairs and downstairs and providing support for the first and second footpaths; the plurality of hanging parts are arranged outside the telescopic supporting part and used for supporting the stairs; one end of any one suspension part is fixedly arranged on the base part of the deep foundation pit, and the other end of the suspension part is fixedly arranged on the telescopic supporting part, so that the upstairs and downstairs can be arranged in the inner space of the deep foundation pit in a suspension manner; the first and second footpaths are installed in an inner space defined by a telescopic support, wherein: the telescopic supporting part comprises a plurality of telescopic rods, the first step road is respectively arranged between two telescopic rods which are arranged on the same side and have different axes, the second step road is respectively arranged between two telescopic rods on different sides, and the first step road and the second step road are rotationally connected in a non-parallel mode; when pushing force or pulling force is applied to the telescopic rod, the first step way can change a first slope angle of the first step way in a mode of rotating around the second step way; and/or the second footpath can change a second slope angle of the second footpath in a manner of rotating around the first footpath; thereby go up and down stair can be according to first grade angle with the change of second grade angle through folding or the mode of expansion install in the inner space of deep basal pit, thereby make go up and down stair can let the staff descend the deep basal pit gradually or return to the earth's surface gradually.

According to a preferred embodiment, in case the depth of the deep foundation pit is not enough to fully deploy the lowermost said walkway units, the stairs can be erected by disassembling at least one of the first, second, third and fourth walkways I, II in the lowermost said walkway units so that the stairs meet the depth of the deep foundation pit in height; and/or the upstairs and downstairs can adjust the fully unfolded footpath units into a folded state by shortening at least one telescopic rod so as to change a first slope angle of the first footpath and/or change a second slope angle of the second footpath, so that the upstairs and downstairs meet the depth of the deep foundation pit in height.

According to a preferred embodiment, the first step includes a first step I and a first step II arranged in parallel, and the second step includes a second step I and a second step II arranged in parallel, as viewed in a plan view, the first step I, the first step II, the second step I and the second step II defining one of the step units, and the ascending/descending stairs being capable of arranging a plurality of the step units according to a depth of the deep foundation pit; wherein, under the condition that the stairs are completely unfolded, the first footpath and the second footpath are in the following states: viewed in the side view direction, a first slope angle of the first step I and a second slope angle of the first step II are opposite numbers; observing in the direction of a front view, a second slope angle of the second step I and a second slope angle of the second step II are opposite numbers; the walkway units are thus annular channels that enable the staff to gradually descend into deep foundation pits or to gradually return to the surface.

According to a preferred embodiment, the telescopic rods are used for adjusting the first slope angle, the second slope angle and the height of the upstairs and downstairs in a hydraulic driving mode, wherein an electromagnetic flow valve is arranged between each telescopic rod and a hydraulic oil circuit of a hydraulic system; the elongation or shortening of the telescopic rod can be adjusted by adjusting the opening of the electromagnetic flow valve or adjusting the hydraulic pressure; the first slope angle, the second slope angle and the height of the upstairs and downstairs are adjusted based on the extension amount or the shortening amount of the telescopic rod; wherein, the side walls of the telescopic short sections at the two ends of the telescopic rod (3a) are provided with an oil inlet and an oil outlet; the oil inlet hole with the oil outlet hole all with the pipeline sealing connection in the hydraulic circuit.

According to a preferred embodiment, two adjacent telescopic rods are detachably connected, so that the lowest pavement unit can be detached under the condition that the depth of the deep foundation pit is not enough to enable the lowest pavement unit to be completely unfolded; the fixing plates with a plurality of threaded holes matched with the studs are arranged at the two ends of the telescopic rods in a uniform mode, and when the studs are screwed into the two adjacent fixing plates, the adjacent telescopic rods are connected in a detachable mode.

According to a preferred embodiment, the suspension portion comprises at least a first and a second suspension support portion; one end of the first suspension supporting part and one end of the second suspension supporting part are fixedly connected with the foundation part through foundation bolts pre-buried in the foundation part; the other end of the first suspension support part and the other end of the second suspension support part are fixedly connected with the telescopic support part through bolts which are fixedly arranged on a cushion plate of the telescopic support part; wherein, the included angle between the first suspension support part and the second suspension support part is an acute angle under the condition that the upper and lower stairs are completely unfolded.

According to a preferred embodiment, the first and second suspension support portions are provided with strain gauge sensors; the strain gauge sensor is used for monitoring the stress of the first suspension support part and the second suspension support part in the unfolding or folding process of the upstairs and downstairs.

According to a preferred embodiment, the adjacent first and second walkways are rotatably connected by a transfer table fixed to the working space defined by the telescopic supports and positioned at staggered intervals in height between the different telescopic supports in the case of a complete extension of the stairs, the transfer table being provided with an articulation mechanism; the hinge mechanism at least comprises a hinge rotating body and a hinge rod provided with a hinge hole matched with a rotating arc surface in the hinge rotating body; the hinged swivel further comprises a swivel seat; the hinged rod is inserted into the hinged support in an interference fit manner; the first rotating seat is fixedly arranged on the first footpath, and the second rotating seat is fixedly arranged on the second footpath; the first hinged support is fixedly installed on the opposite side of the conversion table and the first footpath, the second hinged support is fixedly installed on the opposite side of the conversion table and the second footpath, and when hydraulic oil is injected into the telescopic short section or discharged, the first footpath and/or the second footpath can extend or shorten to rotate around an axis defined by the hinged mechanism based on the telescopic support part, so that the first slope angle of the first footpath and/or the second slope angle of the second footpath can be changed.

According to a preferred embodiment, a first guard rail is arranged on the first footpath along the length direction of the first footpath, and the first guard rail positioned at the outer side is arranged in a manner of extending to the conversion platform; and a second guard rail is arranged on the second footpath along the length direction of the second footpath, and the second guard rail positioned at the outer side is arranged in a mode of being capable of extending to the conversion table.

According to a preferred embodiment, the first and second walkways each include a tread and a tread support plate; the pedal is arranged on the pedal supporting plate, wherein the pedal is arranged in a telescopic manner in the height direction and/or the length direction; and/or the pedal support plate is arranged in a telescopic way; thus, under the condition that the first slope angle of the first footpath and the second slope angle of the second footpath are changed, the pedals and/or the pedal supporting plates can be freely stretched and contracted to adapt to the length change caused by the change of the first slope angle and/or the second slope angle.

The invention provides a suspended deep foundation pit stair ascending and descending, which at least has the following advantages:

(1) the stairs have different working states, the depth of the stairs in the deep foundation pit can be adjusted by extending or shortening the telescopic supporting part, the height required by construction can be achieved by adjusting the size of the space under the condition of not changing the structure of the stairs, and the technical problem that the stairs need to be assembled continuously by manpower in the conventional stairs is solved. Secondly, the stairs can change the gradient of multiple stairs by adjusting the slope angle of the footpath unit so as to meet the requirements of different construction states.

(2) If the bottommost footpath unit does not meet the fully-unfolded state, the invention can tightly fasten each construction stage of the deep foundation pit to adjust the height in real time by adjusting the length of the telescopic unit and/or the assembly structure of the stairs for meeting the requirement that workers can smoothly enter the deep foundation pit for operation so as to meet each depth in the deep foundation pit construction, thereby overcoming the technical problem that the workers can enter the deep foundation pit for operation only by assisting the stairs to go up and down through an outer tower in the prior art.

(3) The deep foundation pit stairs for going up and down can provide safety and convenience for constructors, and has the advantages of high dismounting speed, high arrangement speed, high turnover rate, high safety performance and the like.

Drawings

FIG. 1 is a schematic front view of a preferred structure of a suspended deep foundation pit upstairs and downstairs provided by the present invention;

FIG. 2 is a schematic left view of a preferred structure of a suspended deep foundation pit upstairs and downstairs provided by the present invention;

FIG. 3 is a schematic view of the present invention in a fully deployed position for going up and down stairs through a suspended deep foundation pit;

FIG. 4 is a schematic diagram of the construction of a walkway unit for going up and down stairs in a suspended deep foundation pit according to the present invention;

FIG. 5 is a schematic diagram of an optimized structure of a telescopic short section for going up and down stairs in a suspended deep foundation pit, provided by the invention;

FIG. 6 is a schematic diagram of an optimized structure of a fixing plate of a telescopic short section for a suspended deep foundation pit to go up and down stairs provided by the invention;

FIG. 7 is a schematic view of a connection structure of two adjacent telescopic short sections of a suspended deep foundation pit upstairs and downstairs provided by the invention;

fig. 8 is a schematic enlarged view of a connection structure between a first step and a second step of the hanging deep foundation pit upstairs and downstairs according to the present invention, i.e., a partial enlarged view of a portion a shown in fig. 4;

fig. 9 is a schematic structural view of a preferred structure of a hinge structure for going upstairs and downstairs in a suspended deep foundation pit according to the present invention;

fig. 10 is a schematic view of an optimal drill structure of the hinge rod for going upstairs and downstairs in the suspended deep foundation pit provided by the invention; and

fig. 11 is a schematic structural view of the step and the step support plate of the suspended deep foundation pit upstairs and downstairs of the present invention, i.e., a partial enlarged view of a portion B shown in fig. 4.

List of reference numerals

1: first lane 4 a: first suspension support part

2: second lane 4 b: second suspension support part

3: the telescopic support portion 12 a: hinge mechanism

4: suspension portion 12 b: hinged swivel

12: the conversion table 12 c: rotary arc surface

1 a: first lane I12 d: hinge hole

1 b: first lane II 12 e: hinged rod

2 a: second lane I12 f: rotary seat

2 b: second lane II 12 g: hinged support

3 a: the expansion link α: first slope angle

3 a-1: fixing plate β: second slope angle

3 a-2: threaded hole

Detailed Description

The following detailed description is made with reference to fig. 1 to 11.

In the description of the present invention, the terms "first", "second", "third" and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first," "second," "third," and so forth may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "inner", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience of description and for simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, the term "detachably" is one of an adhesive, a key connection, a screw connection, a pin connection, a snap connection, a hinge connection, a clearance fit, or a transition fit. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Example 1

The embodiment discloses a suspended deep foundation pit stair ascending and descending, and under the condition that conflict or contradiction is not caused, the whole and/or part of the content of the preferred embodiment of other embodiments can be used as a supplement of the embodiment. Preferably, the upstairs and downstairs may be implemented by the method of the present invention and/or other alternative modules. The stair can provide safety and convenience for the passage of constructors, and has the advantages of simple disassembly and assembly process, high component repeatable utilization rate and the like.

As shown in fig. 1 and 2, the present embodiment provides a suspended type deep foundation pit upstairs and downstairs. The up-down stairs comprise a plurality of first footpaths 1, a plurality of second footpaths 2, a telescopic supporting part 3 and a plurality of hanging parts 4. The first footpath 1 and the second footpath 2 form a plurality of footpath units to provide an installation channel for constructors. And a telescopic support 3 defining a working space for ascending and descending stairs and providing support for the first and

second stairways

1 and 2. The suspension parts 4 are arranged outside the telescopic support parts 3 and are used for supporting the upstairs and downstairs. So that the stairs ascend or descend in a suspended manner occupying a part of the space in the excavation. The partial space is defined by the volume of the stairs. For example, the ascending and descending stairs are installed in the east direction of the foundation pit, and the length, width and height of the ascending and descending stairs after the installation are respectively 4m, 4m and 10m, so that the ascending and descending stairs occupy 160m in the east direction of the foundation pit in a hanging manner³The space of (a). One end of any suspension part 4 is rotatably arranged at the basic part of the deep foundation pit, and the other end is arranged at the telescopic support part 3, so that the upstairs and downstairs can be arranged in the inner space of the deep foundation pit in a suspension manner. The first and

second walkways

1 and 2 are installed in an inner space defined by the telescopic support 3. The telescopic supporting part 3 comprises a plurality of telescopic rods 3a, the first footpath 1 is respectively arranged between two telescopic rods 3a which are arranged on the same side and have different axes, and the second footpath 2 is respectively arranged between two telescopic rods 3a arranged on different sides. The first travelator 1 is rotatably connected to the second travelator 2. The first track 1 and the second track 2 are arranged in a non-parallel manner. When pushing or pulling force is applied to the telescopic rod 3a, the way that the first footpath 1 can rotate around the second footpath 2 is changedThe first slope angle beta of the first footpath and/or the second footpath 2 can be changed in a mode of rotating around the first footpath 1 to change the second slope angle alpha of the second footpath 2, so that the upstairs and downstairs can be installed in the inner space of the deep foundation pit in a folding or unfolding mode according to the change of the first slope angle beta and the second slope angle alpha. When pushing force or pulling force is applied to the telescopic rod 3a, the first step road 1 can change the first slope angle beta of the first step road in a mode of rotating around the second step road 2; and/or the second step 2 can change the second slope angle a of the second step 2 in a rotating manner around the first step 1; thereby the up-and-down stairs can be installed in the inner space of the deep foundation pit through the folding or unfolding mode according to the change of the first slope angle beta and the second slope angle alpha, so that the up-and-down stairs can enable workers to gradually go into the deep foundation pit or gradually return to the earth surface. The stairs have different working states, the depth of the stairs in the deep foundation pit can be adjusted by extending or shortening the telescopic supporting part 3, the height required by construction can be achieved by adjusting the size of the space under the condition of not changing the structure of the stairs, and the technical problem that the stairs need to be assembled continuously by manpower in the conventional stairs is solved; secondly, the stairs can change the gradient of multiple stairs by adjusting the slope angle of the footpath unit so as to meet the requirements of different construction states.

Preferably, in case that the depth of the deep foundation pit is not enough to fully deploy the lowermost walkway unit, the ascending and descending stairs can be constructed to meet the depth of the deep foundation pit in height by disassembling at least one of the first walkway I1a, the first walkway II1b, the second walkway I2a, and the second walkway II2b in the lowermost walkway unit. And/or the ascending and descending stairs can adjust the completely unfolded walkway units to the folded state in a form of changing a first slope angle of the first walkway and/or changing a second slope angle of the second walkway by shortening at least one telescopic rod 3a, so that the ascending and descending stairs meet the depth of the deep foundation pit in height. If the bottommost footpath unit does not meet the fully-unfolded state, the invention can meet the requirement of each depth in the construction of the deep foundation pit by adjusting the length of the telescopic unit and/or the assembly structure of the stairs, so as to overcome the technical problem that the outer tower is required to assist the stairs to go up and down to enter the deep foundation pit for operation in the prior art.

Preferably, as shown in fig. 4, the first lane 1 includes a first lane I1a and a first lane II1b arranged in a parallel manner, and the second lane 2 includes a second lane I2a and a second lane II2b arranged in a parallel manner, as viewed in a plan view. The first step I1a, the first step II1b, the second step I2a and the second step II2b define a step unit, and a plurality of step units can be arranged on the stairs according to the depth of the deep foundation pit. As shown in fig. 3, when the stairs are fully unfolded, the first and

second walkways

1 and 2 are in the following states: viewed in a side view direction, a first slope angle of the first step I1a and a second slope angle of the first step II1b are opposite numbers; viewed in the front view direction, the second slope angle of the second step I2a and the second slope angle of the second step II2b are opposite numbers; the walkway units are thus annular channels which enable the staff to gradually descend into deep foundation pits or to gradually return to the surface. For example, as shown in FIGS. 1 and 2, the first ramp I1a has a first slope angle of 15 and the first ramp II1b has a second slope angle of-15. The second slope angle of the second lane I2a is 15 ° and the second slope angle of the second lane II2b is-15 °. The first slope angle of the first step I1a may also be 20 and 25 °; the slope angles of the first step II1b are-20 degrees and-25 degrees correspondingly. The second slope angle of the second footpath I2a may also be 20 ° and 25 °; the second angle of inclination II2b is-20 ° and-25 ° respectively. Considering that the stairs are a recyclable truss structure, the used parts can be manufactured into standard parts so as to reduce the manufacturing cost and the use cost. Preferably, the first ramp I1a has a first slope angle of 15 ° and the second ramp II1b has a second slope angle of-15 ° in case of a fully deployed up-and-down stairs. The second slope angle of the second lane I2a is 15 ° and the second slope angle of the second lane II2b is-15 °.

Preferably, the telescopic rod 3a adjusts the first slope angle beta, the second slope angle alpha and the height of going upstairs and downstairs in a hydraulic driving mode. Wherein, an electromagnetic flow valve is arranged between each telescopic rod 3a and a hydraulic oil circuit of the hydraulic system. The extension amount or the shortening amount of the telescopic rod 3a can be adjusted by adjusting the opening of the electromagnetic flow valve or adjusting the hydraulic pressure. The first slope angle beta, the second slope angle alpha and the height of going upstairs and downstairs are adjusted based on the extension amount or the shortening amount of the telescopic rod 3 a. For example, the hydraulic system includes a hydraulic pump, a hydraulic oil tank, and a hydraulic circuit. When the hydraulic system injects high-pressure hydraulic oil into the telescopic rod 3a, the telescopic rod 3a can be extended based on the injected high-pressure hydraulic oil. When the hydraulic system recovers the hydraulic oil, the telescopic rod 3a can be shortened to recover the original length. Specifically, telescopic link 3a has two flexible nipple joints at least, and flexible nipple joint realizes extension or shortening under the drive of hydraulic oil pressure, and when stopping to pour into hydraulic oil, flexible nipple joint is forming under the effect of the hydraulic oil of telescopic link 3 a's oil intracavity and is supporting whole stair of going up and down. As shown in fig. 5, the telescopic rod 3a preferably has three telescopic short joints. The number of telescopic rods 3a may also be 2, 4 or more. The telescopic short section is preferably 3 sections in consideration of the supporting effect and the buckling stability of the telescopic rod 3 a. The internal construction of the telescopic rod 3a is already known in the art and is not described in detail again. And the injection or discharge mode of the hydraulic oil can adopt that the side walls of the telescopic short sections at the two ends of the telescopic rod 3a are provided with an oil inlet and an oil outlet. The oil inlet hole and the oil outlet hole are hermetically connected with a pipeline in the hydraulic loop. A hydraulic system may be provided in the walkway unit adjacent to each telescopic pole 3a and marked with safety signs.

Preferably, the adjacent two telescopic rods 3a are detachably connected to each other, so that the lowest pavement unit can be detached when the depth of the deep foundation pit is not enough to fully unfold the lowest pavement unit. Preferably, as shown in fig. 7, two adjacent telescopic rods 3a are connected by a fastener, and the fastener is convenient to detach. For example, as shown in fig. 5 and 6, the two ends of the telescopic rod 3a are integrally provided with fixing plates 3a-1 having a plurality of threaded holes 3a-2 matched with the studs, and when the studs are screwed into the adjacent two fixing plates 3a-1, the adjacent telescopic rods 3a are detachably connected. After the screw bolt is screwed inMatched with a matching nut for further fastening. Preferably, the thread lead angle of the threaded hole 3a-2 is smaller than the equivalent friction angle of a screw pair formed by the stud and the threaded hole 3a-2, so that the fastening connection is reliable and cannot be automatically loosened, and the safety of going upstairs and downstairs is ensured. The lead angle is the angle between the tangent of the helix on the pitch diameter cylinder and the plane perpendicular to the axis of the thread, which affects the self-locking and anti-loosening of the thread. The equivalent friction angle is related to the thread profile angle γ. The thread form angle gamma is the included angle of two side edges of the thread form in the axial section of the thread. The included angle between the side edge of the thread profile and the vertical plane of the thread axis is called a flank angle theta, and the symmetrical flank angle theta is gamma/2. Coefficient of equivalent friction f_vF/cos θ, f is the coefficient of friction. And the equivalent friction angle psi is arctan f_v。

Preferably, as shown in fig. 2, the suspending portion 4 includes at least a first suspending support portion 4a and a second suspending support portion 4 b. Wherein, one end of the first suspension support part 4a and one end of the second suspension support part 4b are fixedly connected with the foundation part through the foundation bolts pre-buried in the foundation part. Wherein the angle between the first 4a and second 4b suspension support portions is acute when the stairs are fully unfolded. The foundation part comprises a concrete foundation and an end column formed by pouring with the concrete foundation, and foundation bolts are embedded in the concrete foundation and the end column. Preferably, the anchor bolts are embedded in a vertical manner inside the concrete foundation and the end posts. Preferably, the foundation portion further embeds shear keys. Preferably, the foundation part is used for excavating a foundation pit according to the design pattern of the foundation after the measurement setting-out is finished. And compacting the excavated foundation pit, cleaning, and pouring a plain concrete cushion layer of C15. After the construction of the plain concrete cushion layer is completed, two-way steel bars are laid on the cushion layer, a concrete cushion block is placed at the bottom end of the lower layer of steel bars, the end column and the ground beam steel bars are bound, foundation bolts are buried underground, concrete is poured after the binding of the steel bars and the formwork are completed, shear keys are placed in the reserved holes of the end column 2 after the initial setting is completed, secondary pouring is carried out, and C35 fine stone concrete is poured. The first and second suspended supports 4a and 4b are installed after the concrete foundation is completed and the design strength for installing the suspended portions is achieved. And a column foot plate is laid on the end column, the column foot plate is welded with the pre-embedded shear key, one end part of the first suspension support part 4a and one end part of the second suspension support part 4b are welded on the column foot plate, and the steel plate laid at the position of the foundation bolt is fastened on the foundation bolt by using a nut. In current steel structure column base design, a shear key is provided when a shear force exceeds a friction force between a column base and concrete. The column base is usually welded on a horizontal steel plate on the bottom surface of the column base by using thicker channel steel or I-shaped steel, and is buried in a shear groove reserved in a concrete foundation.

Preferably, the other end of the first suspension support portion 4a and the other end of the second suspension support portion 4b are fixedly connected to the telescopic support portion 3 by bolts fixedly provided on the pad of the telescopic support portion 3. The other ends of the first and second

suspension support portions

4a and 4b have fixing members with screw holes matching the bolts. Preferably, the pad is integrally connected with the telescopic support part.

Preferably, the first and second

suspension support portions

4a and 4b are provided with strain gauge sensors. Strain gauge sensors are used to monitor the stress of the first and second

suspension support portions

4a, 4b during deployment or folding of the upstairs or downstairs. The stress directly reflects the stress condition of the first and second

suspension support portions

4a and 4b, and when the stress exceeds the yield limit or strength limit of the first and second

suspension support portions

4a and 4b, the stress of the first and second

suspension support portions

4a and 4b can be reduced by changing the length of the telescopic support portion. The stress can be judged by a maximum tensile stress theory, a maximum shear stress theory and a distortion energy theory. Specifically, the strain gauge sensors transmit strain signals to a data processor of the monitoring center in a wired and/or wireless manner. The data processor has the capability of calculating the stress by the strain signal, such as a data operation server and a data processing chip. And then the data processor compares the stress value with the limit values corresponding to the maximum tensile stress theory, the maximum shear stress theory and the distortion energy theory respectively. When the stress value exceeds one of the limit values, the data processor sends an alarm signal to the monitoring center. The constructor can let the length of the support part reduce the stress of the first and second

suspension support parts

4a and 4b based on the alarm signal. Usually, a resistance strain gauge is used as a sensing element of the strain gauge sensor. Resistive strain gages take good advantage of the physical and geometric properties of conductors. When a conductor is stretched by an external force within the elastic limit of the conductor, the conductor cannot be broken or can be narrowed and lengthened due to permanent deformation, and the resistance change of the terminal is large due to the deformation. In contrast, when one conductor is compressed, it becomes wider and shorter, and this deformation causes its terminal resistance to be small. By measuring the resistance of the strain gage, the strain in the area covered by the strain gage can be calculated. The sensitive grid of the strain gauge is a group of parallel wires formed by zigzag arrangement of narrow conductor bars, and the arrangement mode can accumulate the tiny deformation in the base line direction to form a larger accumulated value of resistance variation. The sensing element of the strain gauge sensor may also employ an optical strain gauge, such as a bragg grating strain gauge. The strain is inverted into stress by generalized hooke's law, specifically:

wherein E is the elastic modulus of the material, upsilon is the Poisson ratio of the material, and G is the shear modulus of the material. ε is positive strain, γ is shear strain, and σ is stress.

Preferably, as shown in fig. 4 and 8, the adjacent first and

second walks

1 and 2 are rotatably coupled by a transfer table 12 fixed to a working space defined by the telescopic support 3. The transfer table 12 is provided with an articulation mechanism 12a for the first and

second footpaths

1, 2. The rotating mechanism 12a at least includes a hinged swivel 12b and a hinged rod 12e provided with a hinged hole 12d engaged with the rotating arc 12c of the hinged swivel 12 b. The hinge swivel 12b and the hinge hole 12d are in clearance fit or interference fit. The clearance fit or the interference fit enables the hinge rotator 12b and the hinge hole 12c to rotate mutually and limit axial sliding between the hinge rotator 12b and the hinge hole 12c, and enables the hinge rotator 12b and the hinge hole 12d to rotate more reliably. Preferably, the articulated swivel 12b further comprises a swivel seat 12 f. The rotary body seat 12f and the rotary arc surface 12b are preferably of an integral structure. The hinge rod 12e is preferably inserted into the hinge support 12g in an interference fit manner. As shown in fig. 9, preferably, the first swivel base is fixedly mounted to the first walkway 1. The second rotating seat is fixedly arranged on the second step channel 2. The first articulated support is fixedly mounted on the opposite side of the conversion table 12 to the first walkway 1. The second hinge support is fixedly installed at the opposite side to the second step 2. The fixing mode can adopt a welding mode, can adopt a mode of connecting through a stud to fix, and can also adopt an integrated mode to fix. Preferably, the conversion table 12 may be detachably attached to the telescopic support portion 3, or may be integrally connected to the telescopic support portion 3. In consideration of the strength requirement, stability requirement and telescopic reliability requirement of the telescopic support portion 3, the conversion table 12 is preferably connected to the telescopic support portion in an integrated manner. Preferably, the hinge rod 12e is provided with a plurality of hinge holes 12d in an array, and the corresponding hinge swivel 12b is also provided with a plurality of hinge holes. For example, as shown in fig. 10, 3 pieces 12d are provided in the axial direction of the hinge lever 12 e. When hydraulic oil is injected into the telescopic short section or discharged, the telescopic supporting part 3 extends or shortens, so that the first step way 1 and/or the second step way 2 can rotate around the axis defined by the hinge mechanism, and the first slope angle alpha of the first step way 1 and/or the second slope angle beta of the second step way 2 are/is changed.

As can be inferred from the above structure, the adjacent transfer tables 12 located at different telescopic support portions are offset in height with the up-and-down stairs completely unfolded. Preferably, the transfer table 12 can be used as a resting platform and can also house a hydraulic system. In order to ensure the load-bearing stability and the safety applicability of the conversion table 12, a triangular reinforcing plate integrated with or welded to the telescopic support part 3 is arranged on the bottom surface of the conversion table 12.

Preferably, the first guideways 1 are provided with first guard rails along the longitudinal direction of the first guideways 1, and the first guard rails positioned at the outer side are provided to be extendable to the transfer table 12. A second guard rail is provided on the second footpath 2 in the longitudinal direction of the second footpath 2, and the second guard rail positioned at the outer side is provided in such a manner as to be extended to the converting table 12. The first protective guard and the second protective guard can prevent constructors from falling accidentally when walking, and safety of the construction stairs is improved. Preferably, the first guard rail and the second guard rail are metal guard rails.

Preferably, both the first step lane 1 and the second step lane 2 include a step and a step support plate. The footplate is installed on the footplate supporting plate to provide the constructor with an up-and-down channel. Since the lengths of the first and

second footpaths

1 and 2 are changed during the change of the first and second slope angles of the first and

second footpaths

1 and 2. Thus, the step is telescopically arranged in the height direction. For example, the step may have a corrugated plate that is malleable in the height direction. Two adjacent steps can be connected in the height direction by interference fit, for example, the step at the upper end can not fall off from the step at the lower end in a plug-in manner with the step at the lower end under the condition that the steps are completely unfolded. The pedal support plate is arranged in a telescopic manner. And expansion joints, such as springs, are arranged between the two adjacent pedals in the length direction. The pedal support plate is arranged in a telescopic manner. For example, the pedal support plate is provided with a corrugated plate having ductility. The pedal support plate may be provided as a plurality of support plate units movably connected to each other two by two in an end-to-end manner.

Preferably, all parts of the stair ascending and descending can be manufactured into standard parts, so that the stair ascending and descending can meet the development requirements of a safety protection device in a standardized mode and a tool mode.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A suspended deep foundation pit upstairs and downstairs comprising:

the first footpaths (1) and the second footpaths (2) form a plurality of footpath units to provide a channel for workers;

a telescopic support (3) defining a working space for the upstairs and downstairs and providing support for the first and second walkways (1, 2);

the suspension parts (4) are arranged outside the telescopic supporting part (3) and are used for supporting the stairs;

it is characterized in that the preparation method is characterized in that,

one end of any one suspension part (4) is rotatably arranged on the basic part of the deep foundation pit, and the other end of the suspension part is fixedly arranged on the telescopic support part (3), so that the upstairs and downstairs can be arranged in the inner space of the deep foundation pit in a suspension manner;

the first and second walkways (1, 2) are mounted to an interior space defined by a telescopic support (3), wherein:

the telescopic supporting part (3) comprises a plurality of telescopic rods (3a), the first footpath (1) is respectively installed between two telescopic rods (3a) which are arranged on the same side and have different axes, the second footpath (2) is respectively installed between two telescopic rods (3a) arranged on different sides, and the first footpath (1) and the second footpath (2) are rotationally connected in a non-parallel mode;

when a pushing force or a pulling force is applied to the telescopic rod (3a), the first footpath (1) can change the first slope angle (beta) of the first footpath in a mode of rotating around the second footpath (2); and/or the second walkway (2) can change a second slope angle (a) of the second walkway (2) in a manner rotating around the first walkway (1); the stairs can be arranged in the inner space of the deep foundation pit in a folding or unfolding mode according to the change of the first slope angle (beta) and the second slope angle (alpha), so that workers can gradually go into the deep foundation pit or gradually return to the ground surface through the stairs;

the first walkway (1) comprises a first walkway I (1 a) and a first walkway II (1 b) arranged in parallel in a top view, the second walkway (2) comprises a second walkway I (2 a) and a second walkway II (2 b) arranged in parallel,

the first footpath I (1 a), the first footpath II (1 b), the second footpath I (2 a) and the second footpath II (2 b) define one footpath unit, and a plurality of the footpath units can be arranged on the stairs according to the depth of the deep foundation pit;

wherein, under the condition that the stairs are completely unfolded, the first footpath (1) and the second footpath (2) are in the following states:

the first slope angle of the first footpath I (1 a) and the second slope angle of the first footpath II (1 b) are opposite numbers; the second slope angle of the second footpath I (2 a) and the second slope angle of the second footpath II (2 b) are opposite numbers; the footpath unit is an annular channel which can enable workers to gradually go into a deep foundation pit or gradually return to the ground surface;

the first footpath (1) and the second footpath (2) comprise footplates and footplate supporting plates; the pedal is mounted on the pedal support plate,

wherein the pedals are arranged in a telescopic manner in the height direction and/or the length direction; and/or the pedal supporting plate is arranged in a telescopic way; thus, under the condition that the first slope angle of the first footpath (1) and the second slope angle of the second footpath (2) are changed, the pedals and/or the pedal supporting plates can be freely stretched and contracted to adapt to the length change caused by the change of the first slope angle and/or the second slope angle.

2. Stair ascent and descent according to claim 1, wherein the stair ascent and descent is capable of satisfying the depth of the deep excavation pit in height by disassembling at least one of the first walkway I (1 a), the first walkway II (1 b), the second walkway I (2 a), and the second walkway II (2 b) in the walkway unit of the lowermost floor in case the depth of the deep excavation pit is not sufficient to fully deploy the walkway unit of the lowermost floor; and/or

The upstairs and downstairs can be adjusted to be folded states by shortening at least one telescopic rod (3a) to change a first slope angle of the first footpath and/or change a second slope angle of the second footpath, so that the upstairs and downstairs meet the depth of the deep foundation pit in height.

3. Up and down stairs according to claim 2, characterized in that said telescopic rod (3a) is hydraulically driven for the adjustment of said first slope angle (β), said second slope angle (α) and the height of up and down stairs,

an electromagnetic flow valve is arranged between each telescopic rod (3a) and a hydraulic oil way of the hydraulic system; the elongation or shortening of the telescopic rod (3a) can be adjusted by adjusting the opening of the electromagnetic flow valve or adjusting the hydraulic pressure; the first slope angle (beta), the second slope angle (alpha) and the height of the upstairs and downstairs are adjusted based on the elongation or shortening of the telescopic rod (3 a);

wherein, the side walls of the telescopic short sections at the two ends of the telescopic rod (3a) are provided with an oil inlet and an oil outlet; the oil inlet hole with the oil outlet hole all with the pipeline sealing connection in the hydraulic circuit.

4. Stairs according to claim 3, wherein the adjacent two telescopic rods (3a) are detachably connected to each other so as to detach the lowermost walkway unit in case the deep foundation pit is not deep enough to fully deploy the lowermost walkway unit;

the fixing plates (3 a-1) with a plurality of threaded holes (3 a-2) matched with the studs are integrally arranged at two ends of the telescopic rods (3a), and when the studs are screwed into the fixing plates (3 a-1) corresponding to two adjacent telescopic rods (3a), the adjacent telescopic rods (3a) are detachably connected.

5. Stairs according to claim 4, wherein said suspension portion (4) comprises at least a first suspension support (4 a) and a second suspension support (4 b),

one end of the first suspension supporting part (4 a) and one end of the second suspension supporting part (4 b) are fixedly connected with the base part through anchor bolts pre-buried in the base part; the other end of the first suspension support part (4 a) and the other end of the second suspension support part (4 b) are fixedly connected with the telescopic support part (3) through bolts which are fixedly arranged on a base plate of the telescopic support part (3);

wherein the included angle between the first and second suspension support portions (4 a, 4 b) is an acute angle in the case of a full deployment of the upstairs and downstairs.

6. Stairs according to claim 5, wherein said first suspension support (4 a) and said second suspension support (4 b) are provided with strain gauge sensors;

-said strain gauge sensors are used to monitor the stress of said first and second suspension support (4 a, 4 b) during the unfolding or folding of said upstairs and downstairs;

when the stress exceeds a yield limit or a strength limit of the first and second suspension support portions (4 a, 4 b), the stress may be reduced based on the elongation or contraction of the telescopic support portion (3).

7. Upstairs and downstairs as claimed in claim 6, wherein the adjacent first and second walkways (1, 2) are rotatably connected by a transfer table (12) fixed to the working space defined by the telescopic supports (3) and positioned at different telescopic supports staggered in height at intervals in the case of full extension of the upstairs and downstairs, said transfer table (12) being provided with a hinge mechanism (12 a);

wherein the hinge mechanism (12 a) at least comprises a hinge swivel (12 b) and a hinge rod (12 e) provided with a hinge hole (12 d) engaged with a rotary cambered surface (12 c) in the hinge swivel (12 b); the hinged swivel (12 b) further comprises a swivel seat (12 f); the hinged rod (12 e) is inserted into the hinged support (12 g) in an interference fit manner;

wherein, the first swivel seat is fixedly arranged on the first footpath (1), and the second swivel seat is fixedly arranged on the second footpath (2); a first articulated support is fixedly mounted on the opposite side of the conversion table (12) to the first travelator (1), a second articulated support is fixedly mounted on the opposite side of the conversion table (12) to the second travelator (2),

when injecting hydraulic oil or letting out hydraulic oil in the flexible nipple joint, first pavement (1) and/or second pavement (2) can be based on telescopic support portion (3) extension or shorten and wind the axis rotation that articulated mechanism (12 a) were prescribed a limit to, thereby change first slope angle (alpha) of first pavement (1) and/or the second slope angle (beta) of second pavement (2).

8. Upstairs and downstairs as claimed in claim 7, wherein a first guard rail is provided on the first footpath (1) in a length direction of the first footpath (1), and the first guard rail positioned at an outer side is provided in such a manner as to be extended to the transfer stage (12);

and a second guard rail is arranged on the second step path (2) along the length direction of the second step path (2), and the second guard rail positioned on the outer side is arranged in a manner of being capable of extending to the conversion table (12).