Seismic monitoring of strength in stabilized foundations by P-wave reflection and downhole geophysical logging for drill borehole core

Abstract

Evaluating the subground properties during the initial stage of a construction of building is important in order to estimate the suitability of soil quality to the technical requirements of bearing capacity, resistance to stress, and strength. This study presented the evaluation of the geotechnical properties of soil intended for the construction of Max IV facility of Lund University, performed in fieldwork and laboratory. The in situ methods included drilling boreholes, core sampling and assessment, crosshole measurements, and borehole logging. The laboratory-based measurements were performed at Swedish Geotechnical Institute and combined seismic measurements of drill cores, determination of the uniaxial compressive strength (UCS), and examination of material property: sieve analysis and natural moisture content. UCS was evaluated with regard to velocities of elastic P-waves. The synchronous light test by X-ray diffraction was performed for qualitative analysis of mineral composition of samples. The study applied integrated approach of the diverse geophysical methods to solve practical tasks on the evaluation of foundation strength and geotechnical parameters. This study demonstrated the benefits of integrated seismic and geophysical methods applied to soil exploration in civil engineering for testing quality of foundation materials.

Effects of Water—Binder Ratio on Strength and Seismic Behavior of Stabilized Soil from Kongshavn, Port of Oslo

“…These include the non-destructive ultrasonic tests, which are based on the determination of P-wave velocities and compression characteristics of the soil [75]. The goal of such methods is to evaluate the increase in cementation of soil through recorded P-wave's velocity, which increases along with densities, stiffness and strength of materials [76][77][78]. Hence, the acoustic acquisition and calculation of the elastic wave velocities serves as an indicator and descriptor of success in soil stabilization.…”