Research on Steel Cage Hoisting Equipment in Electric Power Construction

In the process of electric power construction, the form of bored pile bottom foundation is widely used. However, if the method of segmental lifting of steel cage is adopted, it will bring a series of problems. First of all, the combination welding of the two main bars will become very difficult, and its welding strength is difficult to be guaranteed. Second, the welding process takes too long, which may lead to an increased risk of hole collapse. These problems will not only affect the efficiency and quality of power construction, but also threaten the safety of construction personnel. Therefore, in order to solve these problems, it is very important to improve the safety and reliability of the overall lifting process of the steel cage. This paper will introduce the research on the whole lifting of steel cage in power construction in detail, in order to provide useful reference for related projects and help the steady development of national power industry.


Introduction
Steel cage hoisting equipment is an important construction equipment.With the development of civil engineering field, its application is more and more extensive.From the early simple lifting tools to the current automation equipment, steel cage lifting equipment has experienced a long history of development.Its appearance greatly improves the construction efficiency, reduces the manpower input and the safety risk [1].
In bridges, highways, subways and other civil engineering, steel cage is widely used to support and fix structures.Due to the varying weights and shapes of steel cages, specialized lifting equipment is required for handling and installation [2][3][4].With the continuous expansion of the scale of engineering construction, the requirements for steel cage hoisting equipment are becoming higher and higher.
The development of steel cage lifting equipment can be traced back to the early 20th century, when the civil engineering field began to use simple lifting tools, such as wire ropes, pulleys, etc.Although these tools can complete basic lifting tasks, they lack flexibility and safety, and are prone to accidents [3][4][5].The purpose of this paper is to develop a new type of steel cage hoisting equipment, aiming at improving construction efficiency, safety and stability.The equipment will combine advanced mechanical, electronic and information technology, with automatic positioning, stable lifting and intelligent control functions.By studying its structure, working principle and performance index, theoretical support and practical guidance are provided for the design and optimization of the equipment.At the same time, this study will also discuss the development trend of steel cage hoisting equipment, and provide reference for the innovation and development of civil engineering construction equipment in the future.

Structural Characteristics of Steel Cage Hoisting Equipment
Steel cage placement is an important process in the construction of transmission line foundation.At present, most of the steel cage placement is carried out by crane [6].The process is as follows: The crane is driven to the lifting position of the steel cage, the shackle is installed, and then the tail of the steel cage is slowly lifted, and the steel cage is adjusted vertically to the ground through the rotation of the crane.After that, the crane is used to put the steel cage into the hole to complete the lifting cage into the hole [7][8].However, the crane is large in volume and weight, and there are problems of equipment approach and walking as mentioned at the beginning of the article, so it is not suitable for operation in mountainous areas.Therefore, according to the bar cage parameter standard, a bar cage placing module that can be installed on the tool car is designed, as shown in figure 1.The mechanical gripper module is composed of hydraulic gripper, pulley assembly, rotary drive, hydraulic winch, telescopic beam, telescopic cylinder, etc.The hydraulic gripper is controlled by the hydraulic cylinder to open and close, which can be used to grab the steel cage or other heavy materials.The middle and lower two hydraulic grippers are fixed on the stationary end of the expansion beam, and the upper hydraulic gripper is fixed on the active end of the expansion beam, and the expansion beam can be extended and withdrawn through the movement of the expansion cylinder.The pulley assembly can be rotated by rotary drive and can be lifted by hydraulic winch.The steps for placing the steel cage in this module are: (1) Pick up: When picking up the steel cage, drive the tool car near the steel cage, then extend the hydraulic gripper, adjust the height of the hydraulic gripper, so that the hydraulic gripper can grasp the steel cage, control the telescopic cylinder to achieve the maximum distance between the upper and lower grippers, then grasp the steel cage on the ground, and use the lifting device in the mechanical gripper module to hook the tail of the steel cage; (2) Move: Slowly lift the steel cage after holding it firmly, make the steel cage perpendicular to the ground, and then open the machine near the pile hole, fine-tune the position to make the center of the steel cage align with the center of the pile hole; (3) Place 1: By controlling the hydraulic gripper to fall the steel cage, first the upper end hydraulic gripper does not move, the middle and lower end hydraulic gripper is released, the telescopic cylinder is retracted, and the steel cage moves downward.When put into a certain depth, the middle and lower end hydraulic gripper does not move, the upper end hydraulic gripper is released, the telescopic cylinder is extended, the position of the steel cage is unchanged, and the upper end hydraulic gripper is close to the top of the steel cage to grab.Then repeat the above steps until the steel cage is continuously placed in the hole; (4) Placement 2: When the steel cage tail is close to the ground, control the rotary drive so that the front center of the pulley assembly is facing the center of the steel cage, and then drive the hydraulic winch to completely put the steel cage into the hole.
The steel cage hoisting equipment is a kind of equipment specially used for hoisting steel cages, and its structural characteristics include the following points: a.Strong lifting capacity: The steel cage lifting equipment has a strong lifting capacity, and can meet the lifting needs of different specifications and weights of steel cages.
b. Easy operation: The steel cage lifting equipment adopts advanced control system and operation mode, which can quickly and accurately lift operation.
c. High safety: The steel cage hoisting equipment is equipped with a variety of safety protection devices, which can effectively avoid possible safety accidents during operation.
d. Strong maintainability: The steel cage hoisting equipment adopts modular design, which is easy to disassemble and maintain, and can effectively reduce maintenance costs and time.

Design of Steel Cage Hoisting Equipment
In practical engineering applications, the length of the bored pile steel cage is different, which brings some challenges to the lifting operation.In order to adapt to this situation, we specially designed a telescopic beam to achieve the lifting of different lengths of steel cage.This kind of telescopic beam is shown in figure 2. It can adjust the length of the telescopic rod to adapt to different lengths of the steel cage.In this way, no matter how the length of the steel cage changes, the telescopic beam can provide stable and safe lifting support, improving the efficiency and safety of construction.

Design of Telescopic Beam
A telescopic beam is a mechanical arm with telescopic function, which is usually composed of multiple segments, and the segments are telescopic through a mechanism such as an oil cylinder or spring as shown in figure 3. The telescopic arm has a large working range and flexibility, and can be operated at different heights and positions, and is widely used in high-altitude work, rescue, construction and other fields.The steel cage hoisting equipment adopts the design scheme of telescopic beam, and the main body is composed of multi-section high-strength low-alloy rectangular steel pipe with high bending and torsional resistance.The structure static analysis of the telescopic main arm is carried out by ANSYS finite element method [9].The theoretical bending stress is calculated as follows: δ=M*y/I (1) In the formula: δ-Bending stress; M-Bending moment; y-The distance between the section center of the steel pipe and the stress point; I-Moment of inertia of steel tube section.Its bending deformation is calculated as follows: In the formula: ε-Bending deformation; M-Bending moment; L-Bending length of steel pipe; E-Elastic modulus of steel tube; I-Moment of inertia of steel tube section.
The maximum requirements of the rectangular tube can be obtained by using ANSYS finite element analysis and theoretical calculation.

The Design of the Cylinder
The design of telescopic cylinder is very important in the overall lifting scheme of steel cage as shown in figure 4.Moreover, the cylinder is an important component in the hydraulic system, which is used to transmit power and achieve various movements.It is usually composed of a cylinder block, piston and seal, and has a large thrust and load-bearing capacity.The oil cylinder plays an important role in the hydraulic system, which can realize the motion form of linear motion, rotating motion and swinging motion.

Cylinder and Piston Material Selection.
Cylinder and piston are important parts of the cylinder, usually composed of steel or alloy.However, according to the actual working conditions, high-strength alloy steel is selected to improve the durability and reliability of the cylinder.

Selection of Sealing Materials.
The sealing material is an important part of the cylinder, usually made of rubber, polytetrafluoroethylene and other materials.When selecting sealing materials, it is necessary to consider its wear resistance, corrosion resistance, aging resistance and compressibility.For example, rubber seals have good wear resistance and corrosion resistance, and can be applied to some low-speed and light-load conditions; Polytetrafluoroethylene has better aging resistance and compressibility, and can be applied to some high-speed and heavy-duty working conditions [10].

Cylinder Diameter Design.
Cylinder diameter is one of the important parameters of the cylinder, which needs to be designed according to the actual application scenario and design requirements.When determining the cylinder diameter, factors such as maximum working pressure, piston speed and carrying capacity need to be considered to ensure that the cylinder can meet the needs of practical applications.After the nominal pressure and working pressure of the cylinder are selected, the formula of the inner diameter of the cylinder can be calculated where F is the nominal pressure of cylinder, p is the working pressure of the cylinder.

Design of Piston Stroke.
Piston stroke is another important parameter of the cylinder, which usually needs to be designed according to the actual application scenario and design requirements.When determining the piston stroke, it is necessary to consider the piston movement range, load changes and so on [11].

Cylinder Installation Design.
Cylinder installation design is an important part of the cylinder, related to the installation and use of the entire equipment.Therefore, in the design of cylinder installation mode, it is necessary to fully consider its installation space layout, so that it can play a greater role reasonably and effectively.

Conclusion
Through the in-depth research and analysis of steel cage hoisting equipment, this paper puts forward a new design scheme of steel cage hoisting equipment.The scheme has been improved and optimized on the basis of the original equipment, and has higher construction efficiency and safety.
First of all, this paper combs the development of steel cage hoisting equipment, analyzes the characteristics and advantages and disadvantages of equipment in different periods.At the same time, according to the existing problems and deficiencies of the existing equipment, the direction and goal of improvement are put forward.
Secondly, the design scheme of the new steel cage hoisting equipment is described in detail, including the structure, working principle and performance index of the equipment.The equipment adopts advanced mechanical, electronic and information technology to achieve automatic positioning, stable lifting and intelligent control functions, improving construction efficiency, safety and stability.
Compared with the original steel cage hoisting equipment, the new equipment has the following advantages: (a) Automatic positioning: The new equipment adopts advanced positioning technology, which can achieve fast and accurate positioning and improve construction accuracy and efficiency.
(b) Stable lifting: The new equipment adopts a unique lifting mechanism and control system, which can achieve stable and safe lifting and reduce safety risks.
(c) High adaptability: The new equipment can adapt to different shapes and weights of the steel cage, improving the adaptability of the equipment.
(d) Environmental protection and energy saving: The new equipment adopts energy-saving motors and control systems, which can reduce energy consumption and emissions and meet environmental protection requirements.In summary, the newly developed e steel cage hoisting equipment exhibits high levels of innovation and practicality.It has the capability to enhance construction efficiency, safety, and stability, providing robust support for the advancement of civil engineering.In the future, with continuous technological progress and growing application demands, steel cage hoisting equipment is expected to evolve towards greater efficiency, intelligence, and environmental friendliness.