Application of Foam Mud in the Construction of Cut-off Wall
When excavating cut-off wall or driving pile in strata with large soil particle size and good permeabili-ty,problems such as trough(hole)wall collapse,large mud leakage and stuck drilling are common.Due to the characteristics of low density and high viscosity of foam,adding foam to wall protection mud is helpful to pre-vent seepage and reduce leakage,which has a good application prospect.Therefore four kinds of foams such as a-alkenyl sulfonate(AOS),sodium polyoxyethylene ether sulfate(AES),sodium dodecyl sulfate(K12)and complex vegetable protein foaming agent(HT)were selected to test the foaming volume and half-life,and the basic properties of foam mud and foam mud penetration test were carried out.The results showed that the half-life of HT foam was 500min,and whose stable time was the longest;Foam can greatly improve the viscosi-ty of mud,reduce the dynamic shear force and static shear force of mud,which can reduce the mud viscosity re-sistance and the annular energy loss.Under the same conditions,the leakage of foam mud is smaller than that of ordinary mud,and the leakage increases first and then decreases with the proportion of foam.When the pro-portion of foam is 20%,the permeability is the minimum.
万方数据
维普
