Steel bellows material introduction
The material of steel corrugated culvert pipe mainly consists of steel corrugated plate and high-strength bolt connection.
一、 the steel corrugated plate adopts A3 or q235-b hot rolled steel plate commonly used at home and abroad, and the physical and chemical indexes of the steel plate meet the relevant requirements of international GB700.
Anticorrosion method: generally use hot dip galvanized anticorrosion, galvanized amount of 600 grams/square meters, if there are special requirements, can be carried out secondary anticorrosion, inner and outer layer after PE (polyethylene) or epoxy resin secondary anticorrosion treatment, service life can be increased by 50 years.
The size and thickness of the board
In order to facilitate the plate processing, the structure of the installation and connection, improve the precision of the plate production, the size of the plate should be adapted to the needs of different pipe diameter, in order to form a series. The thickness of the plate varies with the size of the structure span. The plate thickness can be selected from 2.5-8 mm.
The waveform of the plate is to improve the stiffness of the plate. The section of the plate is processed from the plate into a wave shape with a certain amplitude. Starting from the processing, assembly and stiffness requirements of the plate, and referring to the waveform of similar products at home and abroad, the wave distance of the tube diameter less than 1.5m is 125mm and the wave height is 25mm.The wave distance of the tube with diameter greater than 1.5m is 200mm and the wave height is 55mm.
二、steel corrugated culvert bolt design points
Steel corrugated culvert is divided into integral installation of corrugated culvert and piecewise installation of corrugated culvert. The overall installation of corrugated culvert pipe bolts for longitudinal connection, the bolt shear effect is small, you can choose ordinary high-strength bolts. Shard installation corrugated culvert pipe mechanics calculation in the process of the design of the premise is: do not consider the lap joint of corrugated pipe, corrugated pipe along the circumferential is uniform, continuous, smooth, yet the actual use sheet of corrugated board, and the use of high strength bolt connection, they because of the design and site construction of this pair of contradictions, determines its installation construction is the key to steel corrugated plate ring to the strength of the connection and the axial connection can and does not consider the strength of the lap joint of whole corrugated pipe is consistent, according to the shard installation corrugated culvert stress characteristic and force characteristic, in combination with the relevant technical specification for construction of steel structure,The main points of designing corrugated culvert bolt are put forward.