超深双轴搅拌法在海相沉积软黏土地层中的应用

Application of biaxial ultra deep mixing method in marine sedimentary soft clay

由于深层搅拌桩法成桩速度快、处理效率高、加固效果良好而广泛应用于基坑工程、水利防渗帷幕及市政路基改良中,从单轴搅拌发展到双轴、三轴搅拌,桩体直径也由0.6 m、0.8 m发展到1.0 m,但限于桩基桅杆高度,国内外现有深搅处理普遍在地下27 m深度以内。随着地下工程的发展,地基处理也越来越深,给施工单位提出新的要求。结合新加坡地铁T302项目1.5 m直径、52 m深度的搅拌桩施工,介绍了超深水泥搅拌桩在滨海海相沉积软黏土层的施工方法,以促进搅拌桩施工方法在类似工程项目中推广。

Deep mixing method is widely used in foundation pit engineering.It is also adopted in water conservancy antiseepage curtain,and in municipal subgrade improvement.This is due to its high speed of construction,high treatment efficiency and good reinforcement effect.From the development of uniaxial mixing to biaxial and triaxial mixing,the pile diameter has also developed from 0.6 m and 0.8 m to 1.0 m.However,due to the limitation of the mast height of the equipment,the existing deep mixing treatments in domestic and abroad are generally within the depth of 27 m.With the development of underground engineering,the foundation treatment is now deeper,which puts forward new requirements to the construction unit.Combined with the Singapore metro T302 project,this paper discusses the construction method of ultra-deep cement mixing pile with 1.5 m diameter and 52 m depth in coastal marine sedimentary soft clay,in order to promote the mixing pile construction technique in similar engineering projects.