Abstract：
To converting the muck excavated by EPB shield from the cutter face to the plastic soil in argillaceous sandstone of Nanning Metro Line one for improving tunneling efficiency, foaming agent was taken as soil improvement material and soil conditioning parameters were determined by laboratory test such as foam ratio, stability and slump. The soil improvement parameters were applied to the construction site and the parameters of shield tunneling showed that soil conditioning techniques used had achieved the desired effect.
