Weeds and shrubs are the main areas within the scope of tunnel site selection. During the field survey, the factors affecting the overall stability of the tunnel should not appear and occur. The selection of tunnel steel supports is also very particular, and there are also some principles that need to be paid attention to in welding construction operations.
There are several points to pay attention to when welding tunnel steel supports:
1. In the open air environment, the welded steel support can build a shed just in case. Be careful not to get rain and snow on the weld.
2. In the cold winter, if the steel plate is more than 9mm, it can be welded in several layers. This is to prevent the temperature from being too low, but in general, welding should be completed at one time and continuously. When welding, the defects left by the welding should be cleared first, and the welding can be continued after there is no problem.
3. In such a low temperature environment, the electrodes and wires used for welding steel supports should be low-hydrogen electrodes with low yield strength and good impact toughness under standard conditions.
4. The welding rods used for welding below zero degrees must be of formal standards, which need to be placed in a baking box of 80 to 100 degrees Celsius, and used when needed. If the electrode has been placed below zero for more than two hours, it needs to be re-baked, but the number of times should be less than three times.
Post time: Apr-01-2022