The practical operation plan for the compaction grouting of cold-drawn seamless steel pipes includes a more subtle part of tunnel construction.
The double holes are cold-drawn seamless steel pipes for fire safety, and the single holes are made of seamless steel pipes. The number of joints of seamless steel pipe and fire safety cold-drawn seamless steel pipe in the same cross section shall not exceed 50*** of the number of pipes.
Before installation, the pipe shed of cold-drawn seamless steel pipe should be cleaned by twist drill or high-pressure air to carry out hole cleaning and mud wall protection, so as to eliminate mud and slag on the hole wall, ensure that the diameter (diameter should not be less than 127cm) and depth meet the regulations and avoid blockage. hole. The pipe shed can be installed by jacking, and it can be connected section by section. The seamless steel pipe used for connecting the pipe and culvert is a hot-rolled seamless pipe with a diameter of 114mm and a wall thickness of 6mm. To carry out the connection, the length of the outer thread opening is 15cm, and the length of the inner thread opening is 30cm.
Therefore, it is stipulated that the machining accuracy must be specified in order to ensure the length of the connection and the tightness.
