Quick-release steel ladder and installation method thereof

Abstract

The present application relates to the technical field of nuclear power station installation, in particular to a quick-release steel ladder and an installation method thereof, the quick-release steel ladder comprising an upper ladder, a middle ladder and side ladders; the bottom of the upper ladder is connected with the top of the middle ladder, and the middle ladder is provided with the side ladders on both sides; the upper ladder, the middle ladder and the side ladders are detachably connected, and the axes of the upper ladder, the middle ladder and the side ladders are parallel to each other. The quick-release steel ladder provided by the present application is mainly installed in the groove position reserved by the pool, the ladder sections have clear division of labor and reliable connection, the construction personnel can safely and smoothly reach the bottom of the pool from the top of the pool, and the technical problems of large space occupation, time and labor consumption and non-reusable of the existing technology are completely solved.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant installation technology, specifically to a quick-release steel ladder and its installation method. Background Technology

[0002] During the on-site installation and construction of nuclear power plants, large modular spent fuel pools and containerized fuel pools are arranged side by side. There is a concave channel on the upper part of the pool isolation wall. When entering the bottom of the pool, it is necessary to pass through a complex path through the top of the pool, the bottom of the concave channel, the side, and the bottom of the pool.

[0003] Because the large modular spent fuel pools and containerized fuel pools are up to 14 meters deep, construction workers mostly carry out tasks such as cleaning, painting, and steel cladding protection of the pool surfaces by erecting scaffolding. However, the transportation, assembly, and dismantling of scaffolding materials consume a lot of manpower. At the same time, the erection of scaffolding requires a large amount of ground space. When construction work needs to be carried out near the scaffolding, it is necessary to repeatedly dismantle and rebuild, which greatly affects the construction efficiency. Summary of the Invention

[0004] (I) The technical problem to be solved by the present invention is that in the existing nuclear power plant on-site installation and construction process, construction workers carry out operations such as cleaning, painting and steel cladding protection of the pool surface by erecting scaffolding. The transportation, assembly and dismantling of scaffolding materials consume a lot of manpower. At the same time, the erection of scaffolding also requires a large amount of ground space. When construction work is required near the scaffolding, it is necessary to repeatedly dismantle and rebuild, which greatly affects the construction efficiency.

[0005] (II) Technical Solution To solve the above-mentioned technical problems, embodiments of the present invention provide a quick-release steel ladder, including an upper ladder, a middle ladder, and a side ladder; The bottom of the upper ladder is connected to the top of the middle ladder, and the side ladders are respectively provided on both sides of the middle ladder; The upper ladder, the middle ladder, and the side ladder are all detachable and connected, and the axes of the upper ladder, the middle ladder, and the side ladder are parallel to each other.

[0006] Furthermore, the upper ladder includes an upper frame and an upper limiting structure; An upper passage area is formed within the upper frame, and the upper passage area is used for the passage of construction personnel; The upper limiting structure is located on the outside of the upper frame. When the upper ladder is installed in the predetermined position, the upper limiting structure can restrict the upper ladder from generating relative displacement.

[0007] Furthermore, the upper frame includes an upper guard plate, an upper step, and an upper ladder bottom crossbar; Two upper guard plates are spaced apart, and multiple upper foot pedals are spaced apart between the two upper guard plates and arranged in two rows along the length of the upper guard plates, forming the upper passage area between the upper guard plates and the upper foot pedals; The bottom of the upper guard plate is provided with the upper ladder bottom crossbar, which is detachably connected to the middle ladder.

[0008] Furthermore, the central ladder includes a main central frame, a main support member, a secondary support member, and a central limiting structure; The top of the middle frame is connected to the bottom crossbar of the upper ladder, and a middle passage area is formed inside the middle frame, which is connected to the upper passage area; Both the main support member and the secondary support member are located on the outside of the central frame. The main support member is located at the bottom of the central frame, and the secondary support member is located above the main support member. The main support member and the secondary support member are used to connect with the side ladder. The central limiting structure is located at the top of the central frame. When the central ladder is installed in the predetermined position, the central limiting structure can restrict the relative displacement of the central ladder.

[0009] Furthermore, the central frame includes a central guard plate, a central step bar, diagonal braces, and a central ladder top crossbar; Two central guard plates are spaced apart, and multiple central foot pedals are spaced apart between the two central guard plates and arranged in two rows along the length of the central guard plates, forming the central passage area between the central guard plates and the central foot pedals; The diagonal brace is located on the side of the central guard plate facing the central passage area; The bottom of the middle guard plate is provided with the middle ladder top crossbar, which is detachably connected to the upper ladder bottom crossbar.

[0010] Furthermore, the main support component includes a main support crossbar, a main reinforcing rib, and a main limiting rod, and the secondary support component includes a secondary support crossbar, a secondary reinforcing rib, and a secondary limiting rod; Both the main support crossbar and the secondary support crossbar are connected to the side wall of the central guard plate. The main limiting rod is located on both sides of the main support crossbar, and the secondary limiting rod is located on both sides of the secondary support crossbar. The axes of the main limiting rod and the main support crossbar, and the axes of the secondary limiting rod and the secondary support crossbar are perpendicular to each other. The main reinforcing rib is provided on the main support crossbar, and one end of the secondary reinforcing rib is connected to the secondary support crossbar, and the other end is connected to the side wall of the middle guard plate.

[0011] Furthermore, the side ladder includes a side ladder beam and side ladder treads; Two side ladder beams are arranged at intervals, and multiple side ladder treads are arranged at intervals between the two side ladder beams along the length direction of the side ladder beams.

[0012] Furthermore, the side ladder also includes a side ladder guard cage; The side ladder guard cage is located on the side of the side ladder beam away from the central ladder. A side passage area is formed between the side ladder guard cage, the side ladder beam, and the side ladder treads. The side passage area is connected to the central passage area.

[0013] Furthermore, the side ladder includes a horizontal brace, an upper hanging rod, a lower hanging rod, and a support platform rod; Multiple cross braces are provided on the side of the side ladder beam facing the central ladder, and are spaced apart along the length of the side ladder beam; The upper hanging rod is located at the top of the side ladder beam, and the lower hanging rod is located below the upper hanging rod and connected to the side ladder beam; The lower hanging rod is also provided at the side ladder beam.

[0014] An embodiment of the present invention provides an installation method for a quick-release steel ladder, comprising the following steps: Step 1: Use hoisting equipment to lower the middle ladder into the reserved groove at the bottom of the pool, correct the position of the middle ladder and adjust its verticality. Step 2: Insert a wedge-shaped pad into the gap between the middle ladder and the side support of the pool recess; Step 3: Use hoisting equipment to lower the upper ladder to the top of the middle ladder. After aligning the upper ladder with the middle ladder, use bolts to pass through the bottom crossbar of the upper ladder and the top crossbar of the middle ladder, and secure the bolts with nuts. Step 4: Use hoisting equipment to lift the side ladder, align the upper and lower hanging rods of the side ladder with the main and secondary support crossbars of the middle ladder, and then lower it into position for installation.

[0015] The beneficial effects of this invention are: This invention provides a quick-release steel ladder, which mainly comprises three sections: an upper ladder, a middle ladder, and side ladders. The bottom of the upper ladder is connected to the top of the middle ladder, forming a continuous vertical passage, allowing construction workers to climb from the top of the pool to the middle ladder. Side ladders are provided on both sides of the middle ladder, extending outwards and vertically downwards from the left and right sides of the middle ladder, forming a secondary vertical passage for construction workers to access the bottom of the pool. The upper, middle, and side ladders are all connected by a detachable connection method, with each section connected by bolts, nuts, and washers. This detachable connection allows the steel ladder to be hoisted and assembled step by step during installation, and to be disassembled in sections after use, facilitating transportation and storage. Furthermore, the axes of the upper, middle, and side ladders are parallel to each other, meaning each section extends vertically. This parallel axis design ensures that construction workers always move vertically during the climb, providing a continuous and stable climbing experience without discomfort caused by sudden changes in direction or angle. The steel ladder is primarily installed in the recessed areas pre-reserved within the pool, with each section clearly defined and reliably connected. Construction workers can safely and smoothly reach the bottom of the pool from the top, completely solving the technical problems of existing scaffolding systems that require large spaces, are time-consuming and labor-intensive, and cannot be reused.

[0016] This invention provides an installation method for a quick-release steel ladder. The method adopts a standardized operation process of segmented hoisting, step-by-step calibration, and bolt tightening to ensure the safety and efficiency of steel ladder installation. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the quick-release steel ladder provided in an embodiment of the present invention; Figure 2 A schematic diagram of the upper ladder structure of a quick-release steel ladder provided in an embodiment of the present invention; Figure 3 A schematic diagram of the middle ladder structure of a quick-release steel ladder provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the side ladder structure of a quick-release steel ladder provided in an embodiment of the present invention.

[0019] icon: 100 - Upper ladder; 101 - Upper limiting structure; 102 - Upper guard plate; 103 - Upper step; 104 - Bottom crossbar of upper ladder; 200-Middle Ladder; 201-Main Support Component; 202-Secondary Support Component; 203-Middle Limiting Structure; 204-Middle Guard Plate; 205-Middle Step; 206-Diagonal Bracing; 207-Middle Ladder Top Crossbar; 208-Main Support Crossbar; 209-Main Reinforcing Rib; 210-Main Limiting Rod; 211-Secondary Support Crossbar; 212-Secondary Reinforcing Rib; 213-Secondary Limiting Rod; 300-Side ladder; 301-Side ladder beam; 302-Side ladder treads; 303-Side ladder guard cage; 304-Horizontal brace; 305-Upper hanging rod; 306-Lower hanging rod; 307-Supporting platform rod; 308-Guard cage hoop; 309-Guard cage upright. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "upper" and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] Example 1 like Figures 1 to 4 As shown, the present invention provides a quick-release steel ladder, including an upper ladder 100, a middle ladder 200 and a side ladder 300; The bottom of the upper ladder 100 is connected to the top of the middle ladder 200, and side ladders 300 are provided on both sides of the middle ladder 200. The upper ladder 100, the middle ladder 200 and the side ladder 300 can all be detached and connected, and the axes of the upper ladder 100, the middle ladder 200 and the side ladder 300 are parallel to each other.

[0024] In this embodiment, the quick-release steel ladder mainly comprises three sections: an upper ladder 100, a middle ladder 200, and side ladders 300. The bottom of the upper ladder 100 is connected to the top of the middle ladder 200, forming a continuous vertical passage that allows construction workers to climb from the top of the pool to the middle ladder 200 via the upper ladder 100. Side ladders 300 are provided on both sides of the middle ladder 200, extending outwards and vertically downwards from the left and right sides of the middle ladder 200, forming a secondary vertical passage for construction workers to access the bottom of the pool.

[0025] Specifically, the upper ladder 100, middle ladder 200, and side ladder 300 are all connected by a detachable method, with each ladder segment connected by bolts, nuts, and washers. This detachable connection allows the steel ladder to be hoisted and assembled step by step during installation, and to be dismantled in sections after use, facilitating transportation and storage. Furthermore, the axes of the upper ladder 100, middle ladder 200, and side ladder 300 are parallel to each other, meaning each ladder segment extends vertically. This parallel axis design ensures that construction workers always move vertically during climbing, providing a continuous and stable climbing experience without discomfort caused by sudden changes in direction or angle. The steel ladder is primarily installed in the recessed areas reserved in the pool, with each ladder segment having a clear function and reliable connection. Construction workers can safely and smoothly reach the bottom of the pool from the top, completely solving the technical problems of existing scaffolding that require large spaces, are time-consuming and labor-intensive, and cannot be reused.

[0026] Preferably, the top of the upper ladder 100, the middle ladder 200 and the side ladder 300 are symmetrically provided with two lifting rings, which can be used by the lifting equipment to lift them stably for placement and assembly.

[0027] According to one embodiment provided by the present invention, such as Figure 1 and Figure 2 As shown, the upper ladder 100 includes an upper frame and an upper limiting structure 101; An upper passage area is formed within the upper frame, which is used for the passage of construction workers; The upper limiting structure 101 is located on the outside of the upper frame. When the upper ladder 100 is installed in the predetermined position, the upper limiting structure 101 can limit the relative displacement of the upper ladder 100.

[0028] In this embodiment, the upper frame is the main load-bearing structure of the upper ladder 100, formed by welding two parallel longitudinal beams and several transverse braces connecting the longitudinal beams, creating a stable rectangular skeleton. The interior of the upper frame forms an upper passage area, which is a space for construction workers to climb and traverse. This upper passage area is enclosed by longitudinal beams and spaced-apart steps; its width and height meet ergonomic requirements, ensuring comfort and safety for personnel during vertical climbing. The top of the upper frame has an interface for construction workers to enter, and similarly, its bottom has an interface for connecting to the middle ladder 200.

[0029] The upper limiting structure 101 is located on the outer side of the upper frame, specifically on both sides of the bottom of the upper frame, and is adapted to the shape of the top edge of the pool recess. When the upper ladder 100 is installed in the predetermined position, the upper limiting structure 101 can naturally engage with the corresponding position of the top edge of the recess, limiting the displacement of the upper ladder 100 in the front-back and lateral directions. Through the form-locking engagement with the edge of the recess, the limiting structure enables the upper ladder 100 to achieve stable suspension without welding, drilling, or chemical anchors.

[0030] According to one embodiment provided by the present invention, such as Figure 1 and Figure 2 As shown, the upper frame includes an upper guard plate 102, an upper step bar 103, and an upper ladder bottom crossbar 104; Two upper guard plates 102 are spaced apart, and multiple upper footboards 103 are spaced apart between the two upper guard plates 102 and arranged in two rows along the length of the upper guard plates 102, forming an upper passage area between the upper guard plates 102 and the upper footboards 103. The bottom of the upper guard plate 102 is provided with an upper ladder bottom crossbar 104, which is detachably connected to the middle ladder 200.

[0031] In this embodiment, two upper guard plates 102 are provided, spaced apart along the width of the steel ladder to form the left and right side boundaries. The upper guard plates 102 can be made of structural steel and extend vertically, serving as the main load-bearing components of the upper frame. That is, the space between the two upper guard plates 102 is the upper passage area. Preferably, the guard plates are equipped with protective netting to ensure the safety of passage personnel.

[0032] Correspondingly, multiple upper footboards 103 are provided, spaced apart along the length (i.e., vertical direction) of the upper guard plate 102 and evenly distributed between two upper guard plates 102. The two ends of each footboard are welded and fixed to the two upper guard plates 102 respectively. The surface of the upper footboards 103 is knurled to increase slip resistance. The upper footboards 103 are arranged in two rows between the two upper guard plates 102, with one row on each side, forming a lateral support for personnel to step on. The spacing of the footboards follows ergonomic requirements to ensure comfort and safety during climbing.

[0033] The upper ladder bottom crossbar 104 is directly connected to the bottom of the two upper guard plates 102, serving as a bottom transverse connector of the upper frame and enhancing the structural rigidity of the bottom of the upper frame. The upper ladder bottom crossbar 104 has connecting holes for detachable connection with the middle ladder 200. Specifically, the upper ladder bottom crossbar 104 and the corresponding top structure of the middle ladder 200 are connected by bolts, achieving precise alignment and secure fixation between the upper ladder 100 and the middle ladder 200.

[0034] Through the combined structure of the upper guard plate 102, the upper step bar 103 and the upper ladder bottom crossbar 104, the upper frame forms a complete vertical passage section that allows people to pass safely, and the bottom has a standardized connection interface for easy connection with the middle ladder 200.

[0035] According to one embodiment provided by the present invention, such as Figure 1 and Figure 3 As shown, the central ladder 200 includes a main central frame, a main support member 201, a secondary support member 202, and a central limiting structure 203; The top of the middle frame is connected to the bottom crossbar 104 of the upper ladder, forming a middle passage area within the middle frame, which is connected to the upper passage area. Both the main support member 201 and the secondary support member 202 are located on the outside of the middle frame. The main support member 201 is located at the bottom of the middle frame, and the secondary support member 202 is located above the main support member 201. The main support member 201 and the secondary support member 202 are used to connect with the side ladder 300. The central limiting structure 203 is located at the top of the central frame. When the central ladder 200 is installed in the predetermined position, the central limiting structure 203 can restrict the relative displacement of the central ladder 200.

[0036] In this embodiment, the top of the middle frame is detachably connected to the bottom crossbar 104 of the upper ladder. The interior of the middle frame forms a central passageway, which is vertically connected to the upper passageway, allowing construction workers to continuously climb from the upper ladder 100 into the middle ladder 200. The bottom of the middle frame rests on the bottom surface of the pool recess and serves as the load-bearing foundation for the entire steel ladder.

[0037] Both the main support member 201 and the secondary support member 202 are located on the outer sides (i.e., the left and right sides) of the central frame. The main support member 201 is located at the bottom of the central frame and connects to the lower part of the side ladder 300. The secondary support member 202 is located above the main support member 201 and connects to the upper part of the side ladder 300. The main support member 201 and the secondary support member 202 together constitute the suspension structure of the side ladder 300, providing two connection points at the top and bottom to ensure the stability and verticality of the side ladder 300 after suspension.

[0038] Secondly, the central limiting structure 203 is set at the top of the central frame. When the central ladder 200 is installed in the predetermined position, the central limiting structure 203 can form an abutment fit with the side wall or bottom surface of the pool groove. A wedge-shaped pad is inserted into the gap between the limiting structure and the side wall of the groove to apply a tightening force from both directions, so as to achieve a stable fixation of the central ladder 200 at the bottom of the groove. The central limiting structure 203 can limit the relative displacement of the central ladder 200.

[0039] According to one embodiment provided by the present invention, such as Figure 1 and Figure 3 As shown, the central frame includes a central guard plate 204, a central step bar 205, a diagonal brace 206, and a central ladder top crossbar 207; Two central guard plates 204 are spaced apart, and multiple central foot pedals 205 are spaced apart between the two central guard plates 204 and arranged in two rows along the length of the central guard plates 204, forming a central passage area between the central guard plates 204 and the central foot pedals 205. Diagonal brace 206 is located on the side of the central guard plate 204 facing the central passage area; The bottom of the middle guard plate 204 is provided with a middle ladder top crossbar 207, which is detachably connected to the upper ladder bottom crossbar 104.

[0040] In this embodiment, two central guardrails 204 are provided, spaced apart along the width of the steel ladder to form the left and right side boundaries, extending vertically. Multiple central treadles 205 are provided, spaced apart along the length of the central guardrails 204, evenly distributed between the two central guardrails 204 in two rows, forming a transverse support surface for personnel to step on. The central treadles 205 have the same specifications as the upper treadles 103, ensuring that the stepping experience for construction personnel when passing through the central ladder 200 is consistent with that of the upper ladder 100.

[0041] Diagonal braces 206 are positioned on the side of the central guard plate 204 facing the central passage area, i.e., on the inner side of the central frame. The diagonal braces 206 are arranged diagonally, connecting the horizontal and vertical members of the central guard plate 204 to form a triangular support structure. The diagonal braces 206 significantly enhance the torsional and bending stiffness of the central frame, preventing deformation of the frame under lateral loads and ensuring the overall stability of the central ladder 200. Preferably, a protective net is also provided on the outer side of the central guard plate 204; however, to facilitate smooth passage between the central ladder 200 and the side ladder 300, a protective net is sufficient between the bottom of the upper guard plate 102 and the top of the side ladder 300.

[0042] A central ladder top crossbar 207 is provided at the top of the central guard plate 204, which laterally connects the two central guard plates 204. The central ladder top crossbar 207 has connecting holes for detachable connection with the upper ladder bottom crossbar 104. The central ladder top crossbar 207 and the upper ladder bottom crossbar 104 are designed with a complementary mating structure, with flat contact surfaces and precisely corresponding connecting holes to ensure that bolts can be easily inserted and tightened.

[0043] According to one embodiment provided by the present invention, such as Figure 1 and Figure 3 As shown, the main support member 201 includes a main support crossbar 208, a main reinforcing rib 209 and a main limiting rod 210, and the secondary support member 202 includes a secondary support crossbar 211, a secondary reinforcing rib 212 and a secondary limiting rod 213. Both the main support crossbar 208 and the secondary support crossbar 211 are connected to the side wall of the central guard plate 204. The main limiting rod 210 is located on both sides of the main support crossbar 208, and the secondary limiting rod 213 is located on both sides of the secondary support crossbar 211. The axes of the main limiting rod 210 and the main support crossbar 208, and the axes of the secondary limiting rod 213 and the secondary support crossbar 211 are perpendicular to each other. The main reinforcing rib 209 is provided on the main support crossbar 208, and one end of the secondary reinforcing rib 212 is connected to the secondary support crossbar 211, and the other end is connected to the side wall of the middle guard plate 204.

[0044] In this embodiment, the main support crossbar 208 is laterally connected to the side wall of the central guard plate 204 and extends outward, serving as a load-bearing component for the lower hook of the side ladder 300. The main support crossbar 208 has sufficient bending and shear strength to withstand the load of the side ladder 300 and the workers on it. The main limiting rod 210 is located on both sides of the main support crossbar 208 (i.e., the front and rear ends of the main support crossbar 208) and is perpendicular to the axis of the main support crossbar 208. The function of the main limiting rod 210 is to restrict the axial sliding of the lower hook of the side ladder 300 on the main support crossbar 208, ensuring that the hook is always within the effective load-bearing range of the main support crossbar 208.

[0045] Correspondingly, the secondary support crossbar 211 is installed on the side wall of the central guard plate 204 above the main support crossbar 208, extending outwards to serve as a support for the upper hook of the side ladder 300. The secondary support crossbar 211 is vertically aligned with the main support crossbar 208, and the secondary support crossbar 211 installed on the opposite side is also aligned with the main support crossbar 208 to ensure that the installation height of the side ladders 300 on both sides is consistent. The secondary limiting rod 213 is installed on both sides of the secondary support crossbar 211, perpendicular to the axis of the secondary support crossbar 211, and is used to limit the axial slippage of the upper hook of the side ladder 300.

[0046] The main reinforcing rib 209 is installed on the main support crossbar 208. To complement the main reinforcing rib 209, a vertical bar is installed on the main support crossbar 208, forming a triangular support. One end of the secondary reinforcing rib 212 is connected to the secondary support crossbar 211, and the other end is connected to the side wall of the central guard plate 204, also forming a triangular support. The diagonal arrangement of the reinforcing ribs effectively enhances the bending stiffness and fatigue strength at the root of the support crossbar, effectively transferring the suspended load to the central frame structure.

[0047] According to one embodiment provided by the present invention, such as Figure 1 and Figure 4 As shown, the side ladder 300 includes a side ladder beam 301 and a side ladder tread 302; Two side ladder beams 301 are arranged at intervals, and multiple side ladder treads 302 are arranged at intervals between the two side ladder beams 301 along the length of the side ladder beams 301.

[0048] In this embodiment, two side ladder beams 301 are provided, and the two side ladder beams 301 are arranged at intervals along the width direction of the side ladder 300, serving as the main load-bearing components of the side ladder 300, and the two side ladder beams 301 form the main load-bearing skeleton. The side ladder beams 301 extend vertically, and their top and middle parts are respectively hooked and fixed to the middle ladder 200.

[0049] Multiple side ladder treads 302 are provided, spaced apart between two side ladder beams 301 along the length (i.e., vertical direction) of the side ladder beam 301. The two ends of the side ladder treads 302 pass through the web of the side ladder beam 301 and are welded and fixed, ensuring a secure connection. The surface of the side ladder treads 302 is treated with an anti-slip coating, and the spacing of the treads follows the same ergonomic requirements as the upper ladder 100 and the middle ladder 200, ensuring the comfort and safety of construction workers when climbing.

[0050] According to one embodiment provided by the present invention, such as Figure 1 and Figure 4 As shown, the side ladder 300 also includes a side ladder guard cage 303; The side ladder guard cage 303 is located on the side of the side ladder beam 301 away from the central ladder 200. The side ladder guard cage 303, the side ladder beam 301 and the side ladder treads 302 form a side passage area, which is connected to the central passage area.

[0051] In this embodiment, the side ladder guard cage 303 is disposed on the side of the side ladder beam 301 opposite to the central ladder 200, i.e., on the outer surface of the side ladder 300. The side ladder guard cage 303 consists of multiple guard cage hoops 308 and multiple guard cage uprights 309. The guard cage hoops 308 are annular or semi-circular transverse hoops, arranged at intervals along the length of the side ladder beam 301, surrounding the perimeter of the side passage area. The guard cage uprights 309 extend along the length of the side ladder beam 301, connecting the guard cage hoops 308 to form a continuous cage-like protective structure.

[0052] The side ladder cage 303, side ladder beam 301, and side ladder rungs 302 form a side passage area, facilitating the movement of construction workers between the central ladder 200 and the side ladder 300. Specifically, the side ladder beam 301 forms the left and right boundaries of the passage area, the side ladder rungs 302 form the bottom step surface of the passage area, and the side ladder cage 303 forms the outer protective boundary of the passage area (i.e., the side facing away from the central ladder 200). This enclosed structure ensures that construction workers have continuous cage protection behind them when climbing the side ladder 300, effectively preventing the risk of falling backward.

[0053] The side ladder guard cage 303 is continuously arranged along the height of the ladder, extending from the top entrance of the side ladder 300 to the bottom exit without interruption. The structural dimensions of the guard cage meet the relevant safety specifications. The spacing of the guard cage hoops 308 and the spacing of the guard cage uprights 309 are designed to ensure the effectiveness of the protection without affecting the normal climbing movements of construction workers.

[0054] According to one embodiment provided by the present invention, such as Figure 1 and Figure 4 As shown, the side ladder 300 includes a horizontal brace 304, an upper hanging rod 305, a lower hanging rod 306, and a support platform rod 307; Multiple horizontal bracing rods 304 are provided on the side of the side ladder beam 301 facing the central ladder 200, and are spaced apart along the length of the side ladder beam 301; The upper hanging rod 305 is located at the top of the side ladder beam 301, and the lower hanging rod 306 is located below the upper hanging rod 305 and connected to the side ladder beam 301. A support rod 307 is also provided at the side ladder beam 301 corresponding to the lower hanging rod 306.

[0055] In this embodiment, multiple horizontal support rods 304 are provided and are located on the side of the side ladder beam 301 facing the central ladder 200, that is, on the inner side of the side ladder 300. The horizontal support rods 304 abut against the inner wall of the pool, thereby forming a certain reserved space. This allows for a gap between the side steps and the inner wall of the pool, preventing the side steps from being too close to the side wall of the pool and causing climbing difficulties.

[0056] The upper hanging rod 305 is located at the top of the side ladder beam 301, extending outward from the upper end of the side ladder beam 301 and bending downward to form a hook structure. The upper hanging rod 305 is used to connect with the secondary support crossbar 211 of the middle ladder 200 and is the suspension point of the upper part of the side ladder 300.

[0057] The lower hanging rod 306 is located below the upper hanging rod 305, extending outward from the side ladder beam 301 and bending downward to form a hook structure. The lower hanging rod 306 is used to engage with the main support crossbar 208 of the middle ladder 200, serving as the suspension point at the bottom of the side ladder 300. The vertical distance between the lower hanging rod 306 and the upper hanging rod 305 precisely matches the vertical distance between the main support crossbar 208 and the secondary support crossbar 211, ensuring that the side ladder 300 remains vertical after installation.

[0058] The support rod 307 is positioned at the location of the side ladder beam 301 corresponding to the lower hanging rod 306, extending outward from the side ladder beam 301 and located below the lower hanging rod 306. After the side ladder 300 is installed in place, the support rod 307 forms surface or line contact with the corresponding structure of the middle ladder 200, serving as an auxiliary support and limiting element.

[0059] During installation, workers align the upper hanging rod 305 of the side ladder 300 with the secondary support crossbar 211 and the lower hanging rod 306 with the main support crossbar 208, then slowly lower it into place until the hook is fully seated in the center of the crossbar. After installation, the side ladder 300 and the middle ladder 200 can be further secured with bolts for double fixation.

[0060] Example 2 This invention provides a method for installing a quick-release steel ladder, comprising the following steps: Step 1: Use hoisting equipment to lower the middle ladder 200 into the reserved groove at the bottom of the pool, correct the position of the middle ladder 200 and adjust its verticality. Step 2: Insert a wedge-shaped pad into the gap between the middle ladder 200 and the side support of the pool groove; Step 3: Use hoisting equipment to lower the upper ladder 100 to the top of the middle ladder 200. After the upper ladder 100 and the middle ladder 200 are aligned, use bolts to pass through the bottom crossbar 104 of the upper ladder and the top crossbar 207 of the middle ladder, and fix the bolts with nuts. Step 4: Use hoisting equipment to lift the side ladder 300, align the upper hanging rod 305 and lower hanging rod 306 of the side ladder 300 with the main support crossbar 208 and the secondary support crossbar 211 of the middle ladder 200 respectively, and then lower it into position for installation.

[0061] In this embodiment, the method is used to install the aforementioned quick-release steel ladder into the large modular fuel pool of a nuclear power plant. The method employs a standardized operating procedure of segmented hoisting, step-by-step calibration, and bolt tightening to ensure the safe, accurate, and efficient installation of the steel ladder.

[0062] Specifically, in step 1, use hoisting equipment (such as a truck crane or crawler crane) to lift the central ladder 200 through the dedicated lifting points pre-installed on it. During hoisting, keep the ladder vertical, ensure the slings are symmetrically arranged, and strictly prohibit diagonal pulling or dragging. Slowly and steadily lower the central ladder 200 into the pre-reserved groove at the bottom of the pool. Construction personnel enter the bottom of the groove through the pre-reserved passage at the top, manually straighten the ladder, calibrate the position of the central ladder 200 to ensure it is aligned with the intended installation wall, and adjust its verticality. Verticality adjustment can be done using shims or top supports until the ladder's vertical and horizontal positions are accurate.

[0063] Step 2: Insert wedge-shaped pads into the gap between the central ladder 200 and the side support of the pool recess. A pre-designed gap exists between the base of the central ladder 200 and the side wall of the pool recess. Wedge-shaped steel pads are inserted into this gap to apply a tightening force from both sides. The wedge-shaped pads are alternately driven in from both sides, tightening the limiting baffles at the ends of the main limiting rod 210 and the secondary limiting rod 213 respectively. The pads should be driven in to ensure reliable contact between the limiting rods and the side wall of the recess, with no visible shaking when the ladder is pushed by hand. After tightening in both directions, the central ladder 200 is initially fixed securely and without shaking at the bottom of the recess.

[0064] Step 3: Use hoisting equipment to lift the upper ladder 100 and precisely position it on top of the pre-fixed middle ladder 200. Construction personnel finely adjust the position of the upper ladder 100, ensuring that its bottom crossbar 104 is perfectly aligned with the top crossbar of the middle ladder 200. After confirming the position is correct, bolts are passed through the pre-drilled connection holes at the corresponding positions of the bottom crossbar 104 and the top crossbar 207 of the middle ladder, and nuts are used to secure the bolts. A torque wrench is then used to evenly tighten all connecting bolts, proceeding symmetrically from the center outwards to ensure a secure and reliable connection.

[0065] Step 4: Use hoisting equipment to lift the side ladder 300, aligning the upper hanging rod 305 and lower hanging rod 306 of the side ladder 300 with the main support crossbar 208 and secondary support crossbar 211 of the middle ladder 200, respectively, and lower it into position, ensuring the hook is fully seated in the center of the crossbar. After installation, use bolts to pass through the pre-set connection holes at corresponding positions on the side ladder 300 and the middle ladder 200, and tighten them evenly with a torque wrench. Repeat this process to install the other side ladder 300. After installation, conduct an overall inspection and acceptance to confirm that the steel ladder is safe for use.

[0066] This installation method requires no welding, drilling, or chemical anchors. The entire process is reversible and will not damage any components. The installation time is significantly shorter than that of traditional scaffolding. Furthermore, dismantling is done in reverse order, and each ladder section can be properly stored for future reuse, thus enabling the steel ladder to be reused.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A quick-release steel ladder, characterized in that, It includes an upper staircase (100), a middle staircase (200), and a side staircase (300). The bottom of the upper ladder (100) is connected to the top of the middle ladder (200), and the side ladders (300) are respectively provided on both sides of the middle ladder (200). The upper ladder (100), the middle ladder (200), and the side ladder (300) are all detachably connected, and the axes of the upper ladder (100), the middle ladder (200), and the side ladder (300) are parallel to each other.

2. The quick-release steel ladder according to claim 1, characterized in that, The upper ladder (100) includes an upper frame and an upper limiting structure (101). An upper passage area is formed within the upper frame, and the upper passage area is used for the passage of construction personnel; The upper limiting structure (101) is located on the outside of the upper frame. When the upper ladder (100) is installed in the predetermined position, the upper limiting structure (101) can limit the relative displacement of the upper ladder (100).

3. The quick-release steel ladder according to claim 2, characterized in that, The upper frame includes an upper guard plate (102), an upper step (103), and an upper bottom crossbar (104). Two upper guard plates (102) are arranged at intervals, and multiple upper foot pedals (103) are arranged at intervals between the two upper guard plates (102) and arranged in two rows along the length of the upper guard plates (102). The upper passage area is formed between the upper guard plates (102) and the upper foot pedals (103). The bottom of the upper guard plate (102) is provided with the upper ladder bottom crossbar (104), and the upper ladder bottom crossbar (104) is detachably connected to the middle ladder (200).

4. The quick-release steel ladder according to claim 3, characterized in that, The central ladder (200) includes a main central frame, a main support member (201), a secondary support member (202), and a central limiting structure (203). The top of the middle frame is connected to the upper ladder bottom crossbar (104), and a middle passage area is formed inside the middle frame. The middle passage area is connected to the upper passage area. The main support member (201) and the secondary support member (202) are both located on the outside of the middle frame. The main support member (201) is located at the bottom of the middle frame, and the secondary support member (202) is located above the main support member (201). The main support member (201) and the secondary support member (202) are used to connect with the side ladder (300). The central limiting structure (203) is located at the top of the central frame. When the central ladder (200) is installed in the predetermined position, the central limiting structure (203) can restrict the relative displacement of the central ladder (200).

5. The quick-release steel ladder according to claim 4, characterized in that, The central frame includes a central guard plate (204), a central step bar (205), a diagonal brace (206), and a central ladder top crossbar (207). Two central guard plates (204) are spaced apart, and multiple central foot pedals (205) are spaced apart between the two central guard plates (204) and arranged in two rows along the length of the central guard plates (204). The central passage area is formed between the central guard plates (204) and the central foot pedals (205). The diagonal brace (206) is located on the side of the central guard plate (204) facing the central passage area; The bottom of the middle guard plate (204) is provided with the middle ladder top crossbar (207), and the middle ladder top crossbar (207) is detachably connected to the upper ladder bottom crossbar (104).

6. The quick-release steel ladder according to claim 5, characterized in that, The main support member (201) includes a main support crossbar (208), a main reinforcing rib (209) and a main limiting rod (210), and the secondary support member (202) includes a secondary support crossbar (211), a secondary reinforcing rib (212) and a secondary limiting rod (213). The main support crossbar (208) and the secondary support crossbar (211) are both connected to the side wall of the central guard plate (204). The main limiting rod (210) is located on both sides of the main support crossbar (208), and the secondary limiting rod (213) is located on both sides of the secondary support crossbar (211). The axes of the main limiting rod (210) and the main support crossbar (208), and the axes of the secondary limiting rod (213) and the secondary support crossbar (211) are perpendicular to each other. The main reinforcing rib (209) is provided on the main support crossbar (208), and one end of the secondary reinforcing rib (212) is connected to the secondary support crossbar (211), and the other end is connected to the side wall of the middle guard plate (204).

7. The quick-release steel ladder according to claim 6, characterized in that, The side ladder (300) includes a side ladder beam (301) and a side ladder tread (302). Two side ladder beams (301) are arranged at intervals, and multiple side ladder treads (302) are arranged at intervals between the two side ladder beams (301) along the length direction of the side ladder beams (301).

8. The quick-release steel ladder according to claim 7, characterized in that, The side ladder (300) also includes a side ladder guard cage (303); The side ladder guard cage (303) is located on the side of the side ladder beam (301) away from the middle ladder (200). A side passage area is formed between the side ladder guard cage (303), the side ladder beam (301) and the side ladder treads (302). The side passage area is connected to the middle passage area.

9. The quick-release steel ladder according to claim 7, characterized in that, The side ladder (300) includes a horizontal brace (304), an upper hanging rod (305), a lower hanging rod (306), and a support platform rod (307). Multiple horizontal bracing rods (304) are provided on the side of the side ladder beam (301) facing the central ladder (200), and are spaced apart along the length of the side ladder beam (301); The upper hanging rod (305) is located at the top of the side ladder beam (301), and the lower hanging rod (306) is located below the upper hanging rod (305) and connected to the side ladder beam (301). The lower hanging rod (306) is also provided with the support platform rod (307) at the side ladder beam (301).

10. A method for installing a quick-release steel ladder, characterized in that, Includes the following steps: Step 1: Use hoisting equipment to lower the middle ladder (200) into the reserved groove at the bottom of the pool, correct the position of the middle ladder (200) and adjust its verticality; Step 2: Insert a wedge-shaped pad into the gap between the middle ladder (200) and the side support of the pool groove; Step 3: Use hoisting equipment to lower the upper ladder (100) to the top of the middle ladder (200). After the upper ladder (100) and the middle ladder (200) are aligned, use bolts to pass through the bottom crossbar (104) of the upper ladder and the top crossbar (207) of the middle ladder, and fix the bolts with nuts. Step 4: Use hoisting equipment to lift the side ladder (300), align the upper hanging rod (305) and lower hanging rod (306) of the side ladder (300) with the main support crossbar (208) and the secondary support crossbar (211) of the middle ladder (200) respectively, and then lower it into position for installation.

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