Small strain stiffness and site-specific Seismic response of nano-silica stabilised soft clay in Kochi, India: a case study

• Published in: Arabian journal of geosciences 2022-01, Vol.15 (1), Article 106
• Main Authors: Thomas, Geethu, Rangaswamy, Kodi
• Format: Article
• Language: English
• Subjects: Bearing capacity; Bender elements; Clay; Computer programs; Dynamic loads; Earth and Environmental Science; Earth science; Earth Sciences; Ground motion; Mechanical loading; Nanoparticles; Original Paper; Response analysis; S waves; Seismic response; Seismic velocities; Shaking; Shear modulus; Shear wave velocities; Silica; Silicon dioxide; Soft clay; Software; Soil conditions; Soil dynamics; Soil properties; Soil stabilization; Soils; Stiffness; Wave velocity
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-021-09315-1

The present work deals with a series of bender-element tests to determine the small-strain shear modulus (G max ) of the soft soil selected for the study and its 1-D ground response analysis using ProShake 2.0 software. The site chosen to procure the soft clay is located in Kochi, Kerala, a fast-growing city in Kerala, even though most of the areas are surrounded by water bodies and low bearing capacity sites. The present study assesses the seismic response of a subsurface soft clay layer and the effect on the ground surface. The treatment with nano-silica can reduce the ground amplification caused by the presence of a soft clay layer. The efficiency of nano-silica in strength improvement has been already investigated and implemented in several in situ stabilisation projects. The shear wave velocity (V s ) of the soft clay has been enhanced to a certain level corresponding to a stiff soil’s wave velocities when the nanoparticles are included. The effect of nano-silica has been perceptible during the ground shaking from the ground response analysis results from ProShake 2.0 software. The need for site-specific ground response analysis and the stabilisation effect on the dynamic soil properties are discussed in this paper. In general, the stabilisation using nano-silica can be successfully implemented in in-situ soil conditions under static and dynamic loading conditions.