C-beam is a kind of strip steel with a certain section shape and size, which is one of the four major types of steel. According to section shape, section steel is divided into simple section steel and complex section steel. What are the problems that should be paid attention to when Jinan C-beam is pulled out?
1. When the C-shaped steel is pulled out after the foundation pit is backfilled, the pulling order and time shall be carefully discussed before the pile is pulled out. Otherwise, the vibration of the pile pulled out and too much soil pulled out will cause ground settlement and displacement, which will harm the existing underground structure and affect the stability of nearby buildings, structures or underground pipelines.
2. First, clamp the pile head of the C-shaped steel with a pile pulling machine and shake it for 1min~2min to loosen the soil around the C-shaped steel and produce liquefaction, reduce the friction resistance between the soil and the pile, and then slowly pull it up. When pulling out the pile, pay attention to the load of the pile driver. If it is difficult or impossible to pull out, the pile pulled out shall be suspended.
The starting point and sequence of pile extraction: For closed C-shaped steel wall, more than 5 corner piles shall be reserved at the starting point of pile extraction. The starting point of pile pulling shall be determined according to the conditions of pile driving, and the jump pull method can also be used when necessary. The pile pulling sequence is opposite to the pile driving sequence.
Oscillation and oscillatory pulling: When pulling out piles, the oscillating hammer can be used to oscillate the sheet pile lock to reduce the adhesion of soil layer, so as to make the pile oscillate during the pulling process.
For the sheet piles that are difficult to clean, the diesel hammer can be used to oscillate 100mm~300mm first, and then the oscillating hammer can be used to replace the oscillating and drawing. For the C-section steel with large drawing resistance, the intermittent oscillation is 15 minutes each time, and the continuous oscillation is less than 1.5 h.
In each process of producing C-shaped steel, the positioning and guiding work shall be done well, the two-way verticality of C-shaped steel shall be strictly controlled, and the wall shall be vertical. Generally, close to the cage can avoid water seepage. As well as sawdust, fly ash, expansive cement and other materials, the auxiliary method of suspension can be adopted. Use it when necessary.
The relevant contents of the problems that should be paid attention to when the C-shaped steel is pulled out are explained here. If you have any doubts or needs about this, please come to our website http://www.jnhscg.com Ask!