Abstract

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Title:: Investigation Into Lateral Displacement of Subsoils Induced by Installing Soil-cement Columns

Author(s):: WANG Zhi-feng; WANG Ya-qiong; XIE Yong-li; Shaanxi Provincial Major Laboratory for Highway Bridge & Tunnel, Chang’an University

Keywords:: ground improvement; soilcement column; field test; lateral displacement; theory of cavity expansion; influence range

Abstract:: During the installation process of soil-cement columns, the surroundings of ground would be disturbed due to injection of grout, which could cause significant lateral displacements of subsoils. Chai’s method and its calculation procedure, which was developed based on the theory of cylindrical cavity expansion, were introduced. Chai’s method was adopted to analyze the field test results of installing two soilcement columns (C1 and C2). The results shows: after the construction of C1, the measured lateral displacements change with the variation of construction depth, and the maximum value can reach to 34 mm, and there are some lateral displacements under the bottom of column; when the installation of C2 is completed, the variation of measured displacements with depth is identical with the trend after the installation of C1, and the maximum value can reach to 72 mm. Chai’s method can be used to predict the lateral displacements caused by installing a single column, however there will be some discrepancy for the case constructing several columns due to that the effects of construction sequence and the column strength cannot be considered in Chai’s method. If the lateral displacement to be less than 10 mm is taken as safety control value, the influence range caused by the installation of single soilcement column is about 9 m away from the column center.