The Study of Sand Hole Collapse Mechanism

When constructed the bored pile in sand layer, it is easily to appear the under-reaming and hole collapsed phenomenon. Then it will lead to the engineering disasters, such as hole collapsed, burying drilling and super party amount of concrete. Through the mechanics analysis of the fine sand in the hole process, we found that the mud turbulence will be broken in the drilling process which can cause the water in the hole to be turbulent fluctuation. The result of turbulent fluctuation is making the slurry wall inside and outside the test pressure difference exceeds the wall shear strength which results in the wall off block. At the end, the sand soil collapse dropping leads to the engineering disaster.