The arch foot is the foundation of the arch rib linear control. The arch foot section positioning construction should pay attention to its geometric size position and the arch pipe diameter, vertical elevation angle, horizontal verticality, to ensure the accuracy of arch rib installation.
In addition, because the arch is with the beam of concrete construction, therefore, in the pouring of concrete, the first ribs steel pipe positioning, installation of steel skeleton will be fixed feet, to prevent displacement in the concrete construction. Arch foot positioning frame installation linear control range ± 10mm.
Ribbed mounting bracket
The installation of Steel Pipe is carried out by bracket method. It is intended to be made of steel pipe and steel section, and the bottom of the bracket is welded with the embedded part of the concrete box girder. The top of the bracket is equipped with the arch rib adjustment structure. Arch ribs installed.
Arch ribs installed
In the factory segmented steel components have been tested, tested assembled and linear adjustment after passing to the site, in the field group welding into hoisting section; welding without damage detection detection using ultrasonic and ray detection methods.
Weld found defective phenomenon, according to the accurate positioning of the flaws, rework processing after re-detection review, until the quality requirements.
The arch ribs are arranged in the left and right sides, both ends of the arch by the arch to the vault in turn, the assembly process to do the pre-camber setting, installation of the brace; each size, linear inspection is correct, and in the design requirements of the temperature range of welding Check the weld quality with work.
Steel Pipe installation Note:
(1) erection of the installation of measuring points in the factory should be set up, the measurement points placed in the sub-node tube non-highest point (each hoisting section are set at both ends), make a mark.
② In the process of erection of ribs, each set of ribs will have an impact on the front erection of the arch ribs, so each set of ribs should be a good frame on the front frame of the ribs interface for re-examination, such as the discovery of error overrun It should be timely correction.
③ In order to reduce the impact of temperature on the arch ribs, the ribs control lofting and acceptance measurement time is generally arranged as much as possible in the morning 7 to 9 pm and 16 to 18 pm period of time, other construction acceptance and construction observation with the progress.
④ the construction of the closure of the arch ribs is the last part of the assembly, is the focus of the arch ribs linear control. For the closure of the steel arch arch section of the arch in the processing should be reserved for a certain margin of processing,Steel Pipe cutting in the installation. Arch ribs should be accurately measured before the installation of the length of the closure of the mouth in order to accurately close. The measurement of the distance from the joint, as well as the cutting and installation of the three processes should be carried out with the same temperature of the temperature to operate to reduce the temperature on the arch ribs, easy to close together.