As a load-bearing structure system, steel structure has many advantages, such as light weight, high strength, good plasticity and toughness, superior seismic performance, high degree of industrial assembly, short construction period, remarkable comprehensive economic benefits, flexible structure system and beautiful shape, so it is more and more widely used in industrial workshop and urban rail. Road (subway) depot warehouse, supermarket and other large-span or Super-large-span buildings. Corresponding to its construction technology, it is necessary to build large reinforced concrete foundations or equipment foundations for these buildings, and to bury structural bolts connecting steel structures (columns) and reinforced concrete foundations. Because of the large foundation of the steel structure (the upper part is mostly quadrilateral), the bolt suspension setting is not easy to fix, and the installation quality of the steel structure is required to be high, so the embedding precision of the connecting bolt becomes the key technology of the installation and construction of the steel structure.
Key Points of Construction Operation
2.1 Construction preparation
2.1.1 The processing anchor bolts of the anchor bolts shall be customized according to the design requirements and accepted on site. The corresponding material certification and inspection report shall be required.
2.1.2 Design and Processing of Forming Die
(1) According to the relative position of the embedded anchor bolt and the axis of the concrete foundation, and considering the assembly requirements of the die, the plane size of the die steel plate is determined, the cross line of the longitudinal and transverse axis of the die steel plate is carved, and then the relative position of the embedded bolt is determined according to the axis of the die, and drilling holes are made. The position and diameter of drilling holes of the die should be in good agreement with the bolt position and diameter of the steel structure column, and the thickness of the steel plate should be 4 mm.
(2) Die steel plate can be assembled on site after being processed. The car pole adopts short scaffold with length of 2.0 m, and the steel bar adopts 18 mm threaded steel or 20 mm steel pipe. The height of the steel bar should be 5-10 cm higher than the pre-embedded bolt to facilitate the use of steel ruler to align the axis.
(3) If the top of the concrete foundation is a short column, it can be considered to dig holes in the center of the steel plate to facilitate concrete pouring.
2.1.3 Control of Measurement Accuracy
According to the coordinates and elevation of Engineering design, the axes and elevation control network are encrypted to facilitate accurate measurement of different parts.
2.2 Construction sequence
According to the plane arrangement of steel structure columns, the embedded bolts are fixed along the longitudinal axis from corner or side columns. If it is a multi-span steel structure, it should be constructed with longitudinal and axial pipeline on both sides of the middle span in order to reduce measurement and construction errors and improve the overall installation accuracy.