1. Project Overview
The space frame dry coal shed is 96m long and has a span of 100m. The space frame is a three-center circular arch space frame structure, and the roof is 0.6mm thick ordinary 820-type color steel plate. The space frame is a positive quadrangular pyramid structure with bolted ball joints. The steel pipes and steel balls of the space frame are made of Q235B steel. The coating of the steel components should be epoxy zinc-rich primer; the bolt balls are forged with 45# steel; the high-strength bolts are made of 40Cr and 20MnTiB steel.
2 Construction technical measures
2.1 Construction preparation
2.1.1 Technical preparation
(1) Through the calculation and analysis of the production quantity of the components of this project, and taking into account some unforeseen factors in the production process, a complete operation plan has been formulated. The process drawing of this project is prepared and issued by a number of engineers according to the construction drawing, and the material supply department organizes the materials in combination with the factory inventory. The production department reasonably allocates production factors to provide the necessary conditions for the installation of the space frame. It is required electricians, scaffolders, installers, welders and other personnel working on the site must cooperate closely to solve the problems arising during the on-site construction in a timely manner to ensure the normal operation of the on-site construction.
(2) The production and installation of this project are difficult, the construction site is relatively compact, and there are many cross-operations between different types of work. Therefore, the construction plan must be reasonably designed, the construction sequence must be arranged, and manpower, material resources, and mechanical equipment must be allocated to ensure the overall construction of the project. continuity;
(3) During the construction process of hoisting operation and high-altitude operation, the safety operation rules and safety system should be strictly implemented
2.1.2 Material Preparation
(1) It is required that the electric welding machines, levels, theodolites, total stations, truck cranes, and other equipment used must have good working performance and can meet the needs of on-site construction; this equipment should be checked and implemented before construction.
(2) Installation materials such as rods and high-strength bolts should be organized in advance to enter the site and the quality of the materials should be ensured, and the material quality assurance certificate and test report should be obtained before entering the construction site. The materials entering the construction site shall be sampled again according to the specification requirements, or shall be tested as a whole.
2.1.3 Operating Conditions
Before the installation and construction of the spatial structure of the dry coal shed, the bolt balls, rods, supports, supports, etc. have been manufactured, and they have passed the test according to the requirements of the specification and are transported to the site for installation. Materials and rental goods transported to the site Materials (fasteners, scaffolding, springboards, etc.) must be neatly stacked at the designated location and marked with signs; each process must be completed after the previous process is completed and the acceptance visa has been obtained before entering the next process. construction;
3 Construction methods and process quality control measures
3.1 Main construction plan
3.1.1 Overall scheme of space frame installation
Set up the installation platform with scaffolding → bulk three-span circular arch space frame at high altitude → commissioning → fixed support → high-altitude small unit hoisting method installation → space frame level installation → paint spraying.
3.2 space frame installation process
Local installation platform, the installation method of high-altitude small unit hoisting.
From the 11th axis to the 13th axis, the vertical and horizontal are 1200mmx1200mmx1200 (step distance), the width is 12 meters, and the length is 50 meters.
3.2.2 Local installation
Platform high-altitude small unit hoisting method Install 2-3 space frames of circular arch space frames on the scaffolding platform by the high-altitude bulk method. After the installation is completed, the supports are fixed. The subsequent ring space frame members are installed by the high-altitude small unit hoisting method. Assembled into small units on the ground, and transported to the node by a truck crane (when installing at the bottom, one 25T and one 50T truck will be used. The construction personnel adjust the positions of the rods in their respective positions at the corresponding positions, and initially connect the rods. Locate the spatial location of the node, which is connected to all members of the completed structure, and then install it in place. After all, rods are installed, use a wrench to tighten all rods of the joint. Continue the installation of the next node, and so on until the space frame is installed to the specified position.