Estimating settlement of sand caused by construction vibration

Abstract

Construction and maintenance of buildings and roads, and normal traffic activities, all generate vibrations in nearby structures. Multiple investigations showed that in most cases the levels of vibration were too low to produce direct structural damage based on the vibration limits in existing codes. In current practice, recommended vibration criteria limits seldom take into account settlement of foundation soils due to repetitive vibrations, particularly the cumulative effects of long-term repeated exposure. Many different parameters play an important role in the evaluation of vibrational densification of granular soils. They include vibration characteristics (amplitude, frequency, number of cycles), source of vibration, distance to that source, soil parameters (attenuation characteristics, grain size distribution, density, moisture content), and state of stresses in soil layers vulnerable to vibration. This paper describes a method to predict in-situ settlement of sands caused by pile driving or vehicular traffic with a laboratory developed polynomial model. Extrapolation from laboratory to insitu conditions are derived. Attenuation characteristics of soils are accounted for. Several case histories were investigated in detail to show practical applications of the proposed method.