Abstract: A comprehensive underground utility culvert structure in Zhongshan is to be constructed with open-cut and cover excavation method and the soil mixing wall (SMW) constructed columns is used for the supporting structure. In this paper, the field monitoring data and numerical simulation analysis methods are used to analyze the excavation deformation caused by following four factors: column insertion ratio, column diameter, transverse spacing of internal bracing and vertical spacing of internal bracing. The conclusions can be obtained: (1) The formulas for predicting the maximum horizontal displacement and maximum surface settlement of the SMW constructed columns are derived through analysis; (2) The diameter the SWM column is the most significant factor affecting the horizontal displacement and maximum surface settlement of the supporting structure, and the other influencing factors are column insertion ratio, transverse spacing of supports and vertical spacing of supports in order. The horizontal displacement and maximum surface settlement of SMW column are inversely proportional to the insertion ratio and diameter of SMW columns, and directly proportional to the horizontal and vertical spacing of support.

Key words: Comprehensive Utility Culverts, Soil Mixing Wall, OpenCut and Cover Method, Numerical Analysis