Impact of Dismantled Sheet Pile Vibration on Cohesive Soil Parameters

Abstract

The dynamic impact of geotechnical works can affect subsoil, as well as structures and technical devices. In order to prevent hazards resulting from vibration, the monitoring of geotechnical works execution is necessary. This paper presents an analysis of the relationship between the vibration caused by pulling out the sheet pile and the variability of cohesive soil parameters. The authors present the case study of a construction site in Wroclaw (Lower Silesian Province, Poland). The sheet pile profiles were used as a temporary protection of the foundation excavation. After the underground floors were constructed, the sheet piles were pulled out from the ground using vibrating techniques. This is a typical action to recover steel profiles that can be reused. While the sheet piles were being pulled out, the cohesive soil adhered to steel surfaces. In order to analyse the impact of dismantled sheet pile vibration on the variability of soil parameters, laboratory tests of basic soil physical and mechanical properties were carried out. The results were then compared with the primary parameters of soil as specified in the geotechnical documentation, which had been made at the initial stage to determine the geotechnical conditions for the foundation of the designed building. The comparison has shown a negative effect of vibrations on soil properties, including a decrease in the strength parameters, as well as an increase in the liquidity index and compressibility. In this case, an increase in the earth pressure on the existing underground structures and a reduction of the bearing capacity of shallow foundations may occur. Therefore, the vibration monitoring during sheet pile dismantling process is also very important.