水泥搅拌桩加气搅拌技术在南通海相软土地基中的应用

Application of Cement Mixing Pile with Gaseous Stirring Technology in Nantong Marine Soft Soil Foundation

水泥搅拌桩是国内滨海软土地区较常使用的一种软基处理施工方法,但在滨海相沉积土层中容易出现水泥搅拌桩机钻头难以下切穿过粉砂"硬壳层"的技术难题。文章从粉砂层阻碍搅拌桩机钻头下切的原因入手,通过尝试改进搅拌桩机局部构造、引入高压气体冲破粉砂土对钻头叶片的包裹,同时冲散钻头周围粉砂层土体,达到冲破粉砂"硬壳层"的目的。通过两种搅拌桩机施工试验对比,有效验证了加气搅拌桩技术的可行性和可靠性。

Cement mixing pile is a kind of soft foundation treatment construction method commonly used in coastal soft soil area in China.However,in the littoral sedimentary soil,the technical problem of cement mixing pile drill is difficult to cut through the "hard shell"of powder sand.In this paper,starting from the reasons why the cutting of the drill bit of the mixing pile machine is impeded by the silt layer,through trying to improve the local structure of the mixing pile machine,the high-pressure gases are used to break through the silt layer encasing the bit blade,and'at the same time,powder sand soil around the drill bit is broken down,so as to achieve the goal of breaking through the silty "hard shell".Through the comparison of two kinds of mixing pile machine,the feasibility and reliability of the technology of aerated mixing pile are verified.