The Seismic Behavior of Block Type Deep Soil Mixing

Abstract

Deep soil mixing method (DSM) is a novel in situ technology in soil improvement in which different cementitious materials are mixed with soil and form a soil-cement column with improved engineering characteristics. Due to the configurations of these improved soil-cement columns, different types of DSM are formed, such as wall type, grid type, block type, etc. Due to the expansion in the construction of massive industrial structures, the use of block type DSM to control the settlements has grown. In order to use this soil improvement under the foundation of different structures, it is essential to study the seismic behavior of this mixture using site response analysis and wave propagation. In this paper, the seismic behavior of block type DSM is studied through fully nonlinear analyses. Nonlinear soil is modeled using the overlay method, which uses the parallel element modeling concept. Whereas, the DSM is modeled with elastic perfectly plastic behavior. It is observed that utilizing block type DSM has positive effects in seismic response of the soil layer, such as a considerable reduction in surface response acceleration.

Keywords:
block type deep soil mixing (DSM); soil improvement; seismic behavior; soil-cement mixture; nonlinear analyses; overlay method; Mohr-Coulomb criterion; surface response acceleration

Graphical abstract