Study of seismic response of soils in microseismic soundings of dams

Abstract

The basic fundamentals of spectral analysis of horizontal and vertical components of microseismic noise for studying the geological structure of dams are presented. The issues of constructing deep sections of three dynamic parameters of microseisms are considered. The aim of the work is to study the seismic reaction of soils during microseismic sounding of hydraulic structures. The main objectives of the research include the comparison of deep sections of soil reinforcement coefficients with sections of transmission ratios and data from other geophysical methods. As a result of microseismic sounding of three hydraulic structures, it was found out that the seismic reaction of the clay core of dams differs significantly from the surrounding soils. The amplification coefficients in the bedrock and dispersed soils of the aeration zone are characterized by minimal values. For water-saturated clays, these values are 5–10 times higher, which may indicate that the main reason for the increase in the level of microseismic noise is an increase in the overall porosity and moisture of soils. It is noted that the amplification coefficients of horizontal microseisms are more noise-resistant and detailed compared to the parameters of vertical microseisms. It is stated that deep sections of dynamic microseism parameters allow us to confidently distinguish the main elements of the structure of soil dams, as well as to identify probable zones of increased filtration.

Keywords

• microseisms
• dynamic characteristics
• spectral gain
• h/v-ratio
• dams