Sinking courtyard stair structure
By using the design of the intermediate frame cantilever stair plate and platform plate in the sinking courtyard staircase, the problem of insufficient aesthetics and durability of the components at the corners of the stairs is solved, and a safer and more durable stair structure is achieved.
Patent Information
- Application Number
- CN202420793867.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-16
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-04-16
AI Technical Summary
When designing sinking courtyard stairs in the prior art, conventional methods require the installation of stair beams and stair columns at the corners of the stairs, which affects the aesthetics of the building and may interfere with the evacuation of people. At the same time, the durability of steel structure stairs is relatively low.
A sinking courtyard stair structure is adopted. This structure cantilever stair slabs and platform slabs around the middle frame to form a stable force transmission system, avoiding the installation of stair beams and stair columns at the corners of the stairs, and using reinforced concrete materials to Improve durability.
It ensures the stress safety and durability of the stair structure without affecting the beauty of the building and evacuation of people. It is suitable for stairs with more running numbers and reduces maintenance costs.
Smart Images
Figure CN222477985U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of building engineering staircase structures, in particular to a sunken courtyard staircase structure. Background Art
[0002] In the expression of outdoor space of buildings, public activity square is a place for people to move and rest. Different from the conventional activity square which is close to the vertical elevation of the urban road, the sunken courtyard square adopts the method of lowering the overall square elevation to be lower than the outer road elevation. This not only meets the lighting requirements of the local rooms on the first underground floor, but also better distinguishes the sight lines of people and vehicles in the square and the road. Commonly used vertical transportation mostly adopts stairs or elevators. Among them, the stairs required for evacuation not only have to bear the role of transportation, but also become a small landscape of the sunken courtyard.
[0003] At present, conventional stairs mostly adopt the method of setting stair beams and stair columns at the corners of the stairs to bear the load of the integrated stairs. This method is feasible for indoor stairs, and its stair beams and stair columns can be hidden in the building wall without affecting the beauty of the building. However, in outdoor stairs such as sunken courtyards, setting stair beams and stair columns at the corners of the stairs will not only directly affect the beauty of the building, but also interfere with the evacuation of people.
[0004] Related documents also disclose that stair columns are set at the corners of stairs at a lower position that does not affect the line of sight, so as to avoid the influence of stair columns on the appearance and the evacuation of people, but stair beams with larger component sizes are still required. Moreover, this method is only applicable to stairs with two or less runs, and cannot be used for stairs with more runs. There are also documents that use steel structure stairs without stair columns at the corners of stairs to replace reinforced concrete stairs, but in the outdoor environment of the sunken courtyard, the durability of steel is lower than that of reinforced concrete. Utility Model Content
[0005] The purpose of the utility model is to provide a sunken courtyard staircase structure in order to overcome the defects of the prior art that the arrangement of multi-flight stairs is inseparable from the load-bearing structure arranged around, which affects the beauty of the sunken courtyard stairs and the durability of the steel structure stairs is low.
[0006] The purpose of the utility model can be achieved through the following technical solutions:
[0007] A sunken courtyard staircase structure, which is fixed on the outer wall of the sunken courtyard, and comprises an intermediate frame, a staircase board and a platform board;
[0008] The middle frame is arranged in parallel on one side of the outer wall of the sunken courtyard, one side of the platform board is connected to the middle frame, and the other side is connected to the outer wall of the sunken courtyard, the platform boards are staggered on both sides of the middle frame, the stair boards are fixed on the left and right sides of the middle frame, the stair boards are cross-distributed on the front and back sides of the middle frame, and both ends of the stair boards are respectively connected to the platform boards on both sides of the middle frame.
[0009] Furthermore, the intermediate frame includes a first frame column, a second frame column and a plurality of frame beams, the first frame column and the second frame column are fixed on the ground of the sunken courtyard, one end of the frame beam is connected to the first frame column, and the other end is connected to the second frame column, and each frame beam is distributed obliquely and continuously.
[0010] Further, the frame beam includes a first frame beam, a second frame beam, a third frame beam and a fourth frame beam;
[0011] One end of the first frame beam is connected to the first frame column, and the other end is tilted downward to connect to the second frame column; one end of the second frame beam is connected to the second frame column and contacts the first frame beam, and the other end is tilted downward to connect to the first frame column; the third frame beam is connected to the first frame column and contacts the second frame beam, and the other end is tilted downward to connect to the second frame column; one end of the fourth frame beam is connected to the second frame column and contacts the third frame beam, and the other end is tilted downward to connect to the first frame column.
[0012] Furthermore, the stair tread includes an inner stair tread and an outer stair tread, one side of the inner stair tread is connected to an inner fixed surface formed by the frame beam and the first frame column and the second frame column, and the other side is connected to the outer wall of the sunken courtyard, one side of the outer stair tread is connected to an outer fixed surface formed by the frame beam and the first frame column and the second frame column, and the other side is suspended.
[0013] Furthermore, guardrails are provided on the side of the inner stair tread close to the middle frame, on both sides of the outer stair tread, and on the side of the platform tread away from the middle frame.
[0014] Furthermore, the platform plate includes a first horizontal structural plate, the height of the first frame column is greater than the height of the second frame column, the first horizontal structural plate is fixed between the first frame column and the outer wall of the sunken courtyard, and the first horizontal structural plate is flush with the first floor of the sunken courtyard.
[0015] Furthermore, the stair board includes an inclined structural plate and a plurality of triangular treads, the triangular treads are continuously fixed on the inclined structural plate, the upper surface of each triangular tread is arranged horizontally, the two ends of the inclined structural plate are respectively connected to the platform plate, and one side of the inclined structural plate is fixed on the middle frame.
[0016] Furthermore, the width of the triangular tread is 250-350 mm, the height of the triangular tread is 125-175 mm, and the length of the triangular tread is 900-1800 mm.
[0017] Furthermore, the thickness of the stair tread is not less than one eighth of the length of the triangular tread.
[0018] Furthermore, the thickness of the platform plate is not less than one eighth of the width of the platform plate.
[0019] Compared with the prior art, the utility model has the following advantages:
[0020] (1) The utility model forms a stable force transmission system by cantilevering stair slabs and platform slabs around the middle frame, thereby ensuring the force safety of the structure without the need to set stair beams and stair columns at the corners of the stairs. This is different from the force transmission system of the traditional stair structure that relies on the surrounding walls.
[0021] After removing the stair beams and stair columns at the corners of the stairs, the load is carried out through the middle frame, which can not only express a better architectural shape, but also avoid interference with the evacuation of people. The original function of the stairs is completely retained. The middle frame is the key to the vertical load-bearing of the entire staircase. The middle frame is set parallel to the outer wall of the sunken courtyard to ensure the in-plane stiffness of the middle frame. The stair slab set between the middle frame and the outer wall of the sunken courtyard has a tie effect, which can ensure the out-of-plane stiffness of the middle frame. Ensure the stability of the middle frame under horizontal loads such as earthquakes.
[0022] (2) The inclination angle of the frame beam in the utility model is matched with the elevation setting of the staircase, and a triangular opening is formed between adjacent frame beams, which can not only connect the sight of people flowing up and down, but also provide a certain amount of lighting for the staircase near the outer wall of the sunken courtyard. The entire structure is only composed of the middle frame and the structural plate, which is simple to bear force and easy to construct. The shape is more beautiful and reduces interference with the flow of people. It is particularly suitable for sunken squares with more people, and has a wider range of applications.
[0023] (3) In the utility model, the platform load is transferred to the stair slab, and the stair slab load is transferred to the middle frame. The force of the entire stair structure is clear and the force transmission is reasonable. By arranging the middle frame in parallel with the outer wall of the sunken courtyard and using the stair slab to tie the outer wall of the sunken courtyard, the middle frame has a two-way anti-lateral displacement capability to ensure structural safety.
[0024] (4) The utility model has only two types of components, the intermediate frame and the structural plate, which can be completed by anchoring the steel bars at the connection nodes between the platform plate and the stair plate, and between the stair plate and the intermediate frame. The intermediate frame is relatively independent and can be constructed continuously upward, which is faster than the traditional stair beams, stair columns and platform plate elevation segmented construction. Each structural component can be mass-produced, and the processing cycle is shorter.
[0025] (5) The utility model uses reinforced concrete materials. Compared with the use of steel structure materials for sunken courtyard stairs, the utility model has better durability, stronger ability to resist natural factors and other harmful factors, easier to maintain the shape and properties of the original structure, longer service life and lower maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 A schematic diagram of the structure of the staircase provided by the utility model;
[0027] Figure 2 A structural front elevation view of the staircase structure arrangement provided by the utility model;
[0028] Figure 3 A structural side elevation view of the staircase structure arrangement provided by the utility model;
[0029] Figure 4 A schematic diagram of the structure of the intermediate frame provided by the utility model;
[0030] Figure 5 A schematic diagram of the structure of the stair tread and platform tread provided by the utility model;
[0031] Figure 6 for Figure 5 A partial enlarged view of
[0032] Figure 7 for Figure 1 Schematic diagram of partial connection between stair slab and middle frame;
[0033] Figure 8 for Figure 1 Schematic diagram of partial connection between platform plate and stair plate;
[0034] In the figure, 1, the middle frame, 2, the stair slab, 3, the platform slab, 4, the first floor, 5, the outer wall of the sunken courtyard, 6, the ground of the sunken courtyard, 11, the first frame column, 12, the second frame column, 13, the first frame beam, 14, the second frame beam, 15, the third frame beam, 16, the fourth frame beam, 21, the first stair slab, 22, the second stair slab, 23, the third stair slab, 24, the fourth stair slab, 211, the triangular tread, 212, the oblique structural plate, 31, the first horizontal structural plate, 32, the second horizontal structural plate, 33, the third horizontal structural plate, 34, the fourth horizontal structural plate, 41, the typical connection node between the stair slab and the middle frame, 42, the typical connection node between the platform slab and the stair slab. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0038] In the description of the present utility model, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present utility model.
[0039] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0040] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0041] Example 1
[0042] like Figure 1 As shown, this embodiment provides a sunken courtyard staircase structure, which is fixed on the outer wall 5 of the sunken courtyard. The staircase structure includes a middle frame 1, a staircase board 2 and a platform board 3;
[0043] The middle frame 1 is arranged in parallel on one side of the sunken courtyard outer wall 5, one side of the platform plate 3 is connected to the middle frame 1, and the other side is connected to the sunken courtyard outer wall 5, the platform plates 3 are staggered on both sides of the middle frame 1, the stair plates 2 are fixed on the left and right sides of the middle frame 1, the stair plates 2 are cross-distributed on the front and back sides of the middle frame 1, and the two ends of the stair plates 2 are respectively connected to the platform plates 3 on both sides of the middle frame 1.
[0044] By cantilevering stair slabs and platform slabs around the middle frame, a stable force transmission system is formed without the need to set stair beams and stair columns at the corners of the stairs, thereby ensuring the force safety of the structure. This is different from the force transmission system of traditional stair structures that relies on surrounding walls.
[0045] After removing the stair beams and stair columns at the corners of the stairs, the load is carried out through the middle frame, which can not only express a better architectural shape, but also avoid interference with the evacuation of people. The original function of the stairs is completely retained. The middle frame is the key to the vertical load-bearing of the entire staircase. The middle frame is set parallel to the outer wall of the sunken courtyard to ensure the in-plane stiffness of the middle frame. The stair slab set between the middle frame and the outer wall of the sunken courtyard has a tie effect, which can ensure the out-of-plane stiffness of the middle frame. Ensure the stability of the middle frame under horizontal loads such as earthquakes.
[0046] Preferred implementation mode, as Figure 4As shown, the middle frame 1 includes a first frame column 11, a second frame column 12 and a plurality of frame beams. The first frame column 11 and the second frame column 12 are fixed on the sunken courtyard ground 6. One end of the frame beam is connected to the first frame column 11, and the other end is connected to the second frame column 12. The frame beams are distributed obliquely and continuously.
[0047] Further, the frame beam includes a first frame beam 13, a second frame beam 14, a third frame beam 15 and a fourth frame beam 16;
[0048] One end of the first frame beam 13 is connected to the first frame column 11, and the other end is tilted downward to connect to the second frame column 12; one end of the second frame beam 14 is connected to the second frame column 12 and contacts the first frame beam 13, and the other end is tilted downward to connect to the first frame column 11; the third frame beam 15 is connected to the first frame column 11 and contacts the second frame beam 14, and the other end is tilted downward to connect to the second frame column 12; one end of the fourth frame beam 16 is connected to the second frame column 12 and contacts the third frame beam 15, and the other end is tilted downward to connect to the first frame column 11.
[0049] The inclination angle of the frame beam is matched with the elevation setting of the staircase, and a triangular opening is formed between adjacent frame beams, which not only connects the sight of people going up and down, but also provides a certain amount of lighting for the staircase near the outer wall of the sunken courtyard. The entire structure is composed only of the middle frame and the structural plate, which is simple in force and easy to construct. The shape is more beautiful and reduces interference with the flow of people, especially in the sunken square with more people flow, and has a wider range of applications.
[0050] Specifically, the stair tread 2 includes an inner stair tread and an outer stair tread. One side of the inner stair tread is connected to the inner fixed surface formed by the frame beam and the first frame column 11 and the second frame column 12, and the other side is connected to the sunken courtyard outer wall 5. One side of the outer stair tread is connected to the outer fixed surface formed by the frame beam and the first frame column 11 and the second frame column 12, and the other side is suspended.
[0051] Optionally, guardrails are provided on one side of the inner stair tread close to the middle frame, on both sides of the outer stair tread, and on one side of the platform 3 away from the middle frame 1. The safety of pedestrians is ensured when going up and down the stairs, especially when the stairs are crowded.
[0052] The platform plate 3 includes a first horizontal structural plate 31. The height of the first frame column 11 is greater than the height of the second frame column 12. The first horizontal structural plate 31 is fixed between the first frame column 11 and the outer wall 5 of the sunken courtyard. The first horizontal structural plate 31 is flush with the first floor 4 of the sunken courtyard.
[0053] The platform load is transferred to the stair slab, and the stair slab load is transferred to the middle frame. The force of the entire stair structure is clear and the force transmission is reasonable. By setting the middle frame parallel to the outer wall of the sunken courtyard and using the stair slab to tie the outer wall of the sunken courtyard, the middle frame has a two-way anti-lateral displacement capability to ensure structural safety.
[0054] Wherein, the stair tread 2 includes an oblique structural plate 212 and a plurality of triangular treads 211. The triangular treads 211 are continuously fixed on the oblique structural plate 212. The upper surfaces of the triangular treads 211 are arranged horizontally. The two ends of the oblique structural plate 212 are respectively connected to the platform plate 3. One side of the oblique structural plate 212 is fixed on the middle frame 1. The width of the triangular tread 211 is 250-350mm, the height of the triangular tread 211 is 125-175mm, and the length of the triangular tread 211 is 900-1800mm. The thickness of the stair tread 2 is not less than one eighth of the length of the triangular tread 211. The thickness of the platform plate 3 is not less than one eighth of the width of the platform plate 3.
[0055] The overall staircase structure consists of only two types of components: the middle frame and the structural plate. This can be accomplished by anchoring the steel bars at the connection points between the platform plate and the stair plate, and between the stair plate and the middle frame. The middle frame is relatively independent and can be constructed continuously upwards, which is faster than the traditional staircase beams, staircase columns combined with the platform plate elevation segmented construction. Each structural component can be mass-produced, with a shorter processing cycle.
[0056] Moreover, the staircase structure is made of reinforced concrete material. Compared with the sunken courtyard stairs made of steel structure materials, it has better durability, stronger ability to resist natural factors and other harmful factors, is easier to maintain the shape and properties of the original structure, has a longer service life and lower maintenance costs.
[0057] In combination with the above content, this embodiment also provides a more specific implementation method, including:
[0058] like Figures 1 to 3 As shown, a sunken courtyard staircase structure is mainly fixed to the sunken courtyard ground 6 at the lower part of the middle frame 1, and connected to the sunken courtyard outer wall 5 through the first stair tread 21 and the third stair tread 23, so that the middle frame is fixed in the sunken courtyard. The second stair tread 22 and the fourth stair tread 24 are then cantilevered from the middle frame, wherein the bottom of the fourth stair tread 24 is connected to the sunken courtyard ground 6. Finally, the first horizontal structural plate 31 is cantilevered from the first stair tread 21 and connected to the first floor 4, the second horizontal structural plate 32 is cantilevered from the first stair tread 21 and the second stair tread 22, the third horizontal structural plate 33 is cantilevered from the second stair tread 22 and the third stair tread 23, and the fourth horizontal structural plate 34 is cantilevered from the third stair tread 23 and the fourth stair tread 24. A staircase arrangement that can connect the first floor 4 and the sunken courtyard ground 6 is formed.
[0059] like Figures 4 to 6 As shown, the middle frame 1 is composed of a first frame column 11, a second frame column 12, a first frame beam 13, a second frame beam 14, a third frame beam 15, and a fourth frame beam 16. The cross-sectional dimensions of the frame columns and frame columns are generally 200mm-300mm×400mm-600mm. The stair tread 2 is composed of a first stair tread 21, a second stair tread 22, a third stair tread 23, and a fourth stair tread 24. Each stair tread is composed of a plurality of triangular treads 211 and a diagonal structural plate 212. The platform plate is composed of a first horizontal structural plate 31, a second horizontal structural plate 32, a third horizontal structural plate 33, and a fourth horizontal structural plate 34. According to the actual stair height, stair treads and platform plates can be added or reduced, or the width and height of the steps can be adjusted to achieve different stair lifting heights. Generally, the step width is 250mm-350mm, the step height is 125mm-175mm, and the step length is 900mm-1800mm according to the evacuation width requirements. The thickness of stair treads is generally not less than 1 / 8 of the step length. The thickness of platform treads is generally not less than 1 / 8 of the platform tread width.
[0060] like Figure 7 and 8 As shown, first, after the stair slab is divided into a plurality of triangular treads 211 and an oblique structural plate 212, each stair section plate is connected to the middle frame 1 through the form of "typical connection node 41 between stair slab and middle frame" to form a "stair structure with stair slab". Then, the platform slab 3 is connected to the "stair structure with stair slab" through the form of "typical connection node 42 between platform slab and stair slab" to form a "stair structure with stair slab and platform slab". Finally, the "stair structure with stair slab and platform slab" is connected to a first floor 4, a sunken courtyard outer wall 5, and a sunken courtyard floor 6 to form a sunken courtyard stair structure arrangement.
[0061] The preferred specific embodiments of the utility model are described in detail above. It should be understood that ordinary technicians in this field can make many modifications and changes based on the concept of the utility model without creative work. Therefore, all technical solutions that can be obtained by technicians in this technical field based on the concept of the utility model through logical analysis, reasoning or limited experiments on the basis of the existing technology should be within the scope of protection determined by the claims.
Claims
1. A sunken courtyard staircase structure, the staircase structure is fixed on the outer wall (5) of the sunken courtyard, characterized in that: The staircase structure comprises an intermediate frame (1), a staircase plate (2) and a platform plate (3); The middle frame (1) is arranged in parallel on one side of the sunken courtyard outer wall (5); one side of the platform board (3) is connected to the middle frame (1) and the other side is connected to the sunken courtyard outer wall (5); the platform boards (3) are staggeredly distributed on both sides of the middle frame (1); the stair boards (2) are fixed on the left and right sides of the middle frame (1); the stair boards (2) are cross-distributed on the front and rear sides of the middle frame (1); and the two ends of the stair boards (2) are respectively connected to the platform boards (3) on both sides of the middle frame (1).
2. The sunken courtyard staircase structure according to claim 1, characterized in that: The intermediate frame (1) comprises a first frame column (11), a second frame column (12) and a plurality of frame beams, wherein the first frame column (11) and the second frame column (12) are fixed on the ground (6) of the sunken courtyard, one end of the frame beam is connected to the first frame column (11), and the other end is connected to the second frame column (12), and the frame beams are distributed obliquely and continuously.
3. The sunken courtyard staircase structure according to claim 2, characterized in that: The frame beams include a first frame beam (13), a second frame beam (14), a third frame beam (15) and a fourth frame beam (16); One end of the first frame beam (13) is connected to the first frame column (11), and the other end is connected to the second frame column (12) at an angle downward; one end of the second frame beam (14) is connected to the second frame column (12) and contacts the first frame beam (13), and the other end is connected to the first frame column (11) at an angle downward; the third frame beam (15) is connected to the first frame column (11) and contacts the second frame beam (14), and the other end is connected to the second frame column (12) at an angle downward; and one end of the fourth frame beam (16) is connected to the second frame column (12) and contacts the third frame beam (15), and the other end is connected to the first frame column (11) at an angle downward.
4. The sunken courtyard staircase structure according to claim 2, characterized in that: The stair tread (2) comprises an inner stair tread and an outer stair tread, one side of the inner stair tread being connected to an inner fixed surface formed by a frame beam and a first frame column (11) and a second frame column (12), and the other side being connected to an outer wall (5) of a sunken courtyard, and one side of the outer stair tread being connected to an outer fixed surface formed by a frame beam and a first frame column (11) and a second frame column (12), and the other side being suspended.
5. The sunken courtyard staircase structure according to claim 4, characterized in that: Guardrails are provided on the side of the inner stair tread close to the middle frame (1), on both sides of the outer stair tread, and on the side of the platform tread (3) away from the middle frame (1).
6. The sunken courtyard staircase structure according to claim 2, characterized in that: The platform plate (3) comprises a first horizontal structural plate (31), the height of the first frame column (11) is greater than the height of the second frame column (12), the first horizontal structural plate (31) is fixed between the first frame column (11) and the outer wall (5) of the sunken courtyard, and the first horizontal structural plate (31) is flush with the first floor (4) of the sunken courtyard.
7. The sunken courtyard staircase structure according to claim 1, characterized in that: The staircase board (2) comprises an oblique structural board (212) and a plurality of triangular treads (211), wherein the triangular treads (211) are continuously fixed on the oblique structural board (212), and the upper surfaces of the triangular treads (211) are arranged horizontally, and the two ends of the oblique structural board (212) are respectively connected to the platform board (3), and one side of the oblique structural board (212) is fixed on the middle frame (1).
8. The sunken courtyard staircase structure according to claim 7, characterized in that: The width of the triangular tread (211) is 250-350 mm, the height of the triangular tread (211) is 125-175 mm, and the length of the triangular tread (211) is 900-1800 mm.
9. The sunken courtyard staircase structure according to claim 1, characterized in that: The thickness of the stair tread (2) is not less than one eighth of the length of the triangular tread (211).
10. The sunken courtyard staircase structure according to claim 1, characterized in that: The thickness of the platform plate (3) is not less than one eighth of the width of the platform plate (3).