Abstract: The SMW columns are widely applied in strengthening the urban soft soils because of its advantages of fast installation and good groundwater seepage blocking performance. This paper presents a deep excavation project case history in the saturated soft soils with adjacent old building in Liuyanjing station of Nanchang Metro Line 3. The sequential installation of the conventional SMW columns is easily to induce the disturbance of adjacent building stratum in the early stage of cementsoil hardening. Therefore, the safety of the surrounding buildings cannot be warranted. Two analytical conditions of SMW column sequential and skip installations are established based on the numerical method, and the mechanical responses of the surrounding strata caused by the SMW column installation under different working conditions are compared and analyzed. By setting up the numerical model of different installation length and skip distance, combining the requirement of the installation condition and the efficiency, this paper presents the feasibility and advantage of column skip installation by SMW method in adjacent buildings. According to the analysis combined with the actual installation requirements of the construction method, the construction method of skip one distance is determined. On the conditions of ensuring safety, the disturbance to the surrounding strata is minimized and the installation efficiency is improved.

Key words: SMW Columns, Adjacent Buildings, Skip Installation Method, Numerical Analysis