نوع مقاله : مقاله کامل پژوهشی
نویسنده
گروه مهندسی عمران، دانشکده مهندسی و فناوری، دانشگاه مازندران، بابلسر
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسنده [English]
The Deep Soil Mixing (DSM) grid method is among the most effective techniques for mitigating soil liquefaction, as it enhances shear stiffness and thereby reduces large shear strains and liquefaction potential. Previous studies mostly estimated the reduction factor of liquefaction potential (RCSR) using linear finite element models, where excess pore water pressure and liquefaction effects were neglected. In this study, a three-dimensional nonlinear numerical analysis was conducted using OpenSeesSP, incorporating the advanced multi-surface Drucker–Prager model to simulate soil and DSM grid behavior. The influence of grid spacing (5 m and 10 m) and relative shear modulus (13.3 and 25) on the shear stress reduction factor (Rrd) and the relative acceleration ratio (Ra max) under harmonic loading was investigated. Results indicated that increasing grid spacing from 5 m to 10 m led to nearly a 300% rise in Rrd, while a higher shear modulus produced only a slight decrease in Rrd. Moreover, considering nonlinear soil behavior reduced Rrd at small grid spacing but significantly increased Ra max, reaching approximately 2.5 at the ground surface, compared to less than one in the linear model. The findings suggest that previous empirical relations for Rrd were conservative, yet Ra max estimates in linear models significantly underestimated the impact of liquefaction. Overall, the results highlight that incorporating nonlinear soil behavior and excess pore water pressure in numerical modeling enhances analytical accuracy and leads to more conservative designs in soil improvement projects.
کلیدواژهها [English]
)