Steel structure construction plan
1. On-site installation of the steel structure
(1) Overview of the on-site installation process
The structural form of this steel structure project is a frame. Combined with the component form, weight, position, and the actual situation of the construction site, as well as the performance of various lifting parameters of the tower crane set on the site, the steel structure of this project, adopts a comprehensive installation method.
1. On-site installation method of steel structure:
The weight of the frame columns and beams of the workshop is relatively light, and the hoisting is mainly carried out by a 25-t truck crane.
2. On-site installation sequence of steel structure:
The steel structure hoisting adopts the principle of “first middle, then outer, first column and then beam, first down and then up”. In the middle part of the workshop, a stable frame system is first formed, and then it is advanced to both ends, and the remaining steel columns and beams are installed symmetrically. The sequence is as shown below:
Schematic diagram of the construction sequence of a single factory building (from the middle to the two ends)
(2) Analysis of the main installation components
The main components of this project are steel columns, steel beams, purlins, diagonal braces and other components. The weight is not too heavy, as follows:
(3) Selection and arrangement of lifting equipment
1. The choice of crane
According to the site layout plan, a total of 5 steel structure workshop steel structure projects need to be installed. Combined with the analysis of their lifting performance and working conditions, 4 sets of NK250 25t truck cranes are configured on site.
The main use areas and uses are as follows:
2. The working conditions and performance of truck cranes are as follows:
The rated total lifting capacity of the 25t truck crane is as follows (unit: T):
(4) Steel structure installation process
1. The overall process of installation process (take the freezer as an example)
Re-measurement of anchor bolts → unloading of steel components → incoming inspection of components → direct hoisting of automobile cranes in place → temporary tightening of anchor bolts → temporary tightening of cable wind ropes → adjustment of axis position and verticality of steel columns → steel stud bolts and Fastening and welding of the column foot pressure plate → installation of the next steel column → installation of the tie rod between the steel columns → the formation of the first stable lattice system → the steel roof truss is assembled on the ground and lifted into place by two machines to form the first steel roof truss → Symmetrical installation of columns and roof trusses on both sides → …… → and so on → installation is completed, and the structure is accepted.
2. Steel structure installation area division
The project consists of five parts: meat freezing, meat market, vegetable storage, vegetable market, and open sales area. According to the division of construction flow section, it is divided into five areas. The specific division area is shown in the figure below.
3. The overall installation sequence of the steel structure
According to the overall arrangement of the project, it is planned to arrange two construction teams to carry out the construction at the same time. The overall construction sequence of the five areas is: District 1, District 2… District 5.
For the same workshop, the installation sequence of steel components adopts the method of “reducing errors, from the middle to both ends”.
4. Steel structure installation sequence (take freezer as an example)
(1) Install the first row of steel columns.
(2) Install the second row of steel columns.
(3) Install connecting beams (or tie rods) between steel columns.
(4) Use the double machine to lift and install the first steel roof truss.
(5) Use the double machine to lift and install the second steel roof truss.
(6) Install the purlins between the two roof trusses to form a stable frame system.
(7) Continue to install the steel columns, coupling beams, roof trusses, and purlins of the next rigid frame.
(8) Continue to install the roof truss in the above order, and the supports between the columns are also interspersed for installation.
(9), continue to install.
(10) The roof truss installation is completed.
5. Support installation between columns
The inter-column support and the steel column adopt the combination of gusset plate bolt connection and welding connection. The deviation of production and steel column installation may have a greater impact on its installation. The inter-column support is assembled in the factory and then transported to the site as a whole. to install. The hoisting weight of the inter-column support is relatively light and can be hoisted by a 25-ton truck crane.
The hoisting sequence of the cross-column support is as follows:
When hoisting, it is divided into three monomers 1, 2, and 3 for hoisting respectively. The