Lyöntikairaus

Lyöntikairaus, also known as driven sampling or percussion coring, is a soil sampling method used in geotechnical investigations. It involves driving a sampling tube into the ground using a hammer or a specialized driving tool. The goal is to obtain an undisturbed or semi-undisturbed soil sample within the tube for laboratory analysis. The process typically involves attaching a drive shoe to the end of a hollow sampling tube. This tube is then repeatedly struck by a weight or hammer, forcing it into the soil. The force of impact and the depth of penetration are carefully controlled. Once the desired depth is reached, the sampling tube is withdrawn from the ground, often by pulling or rotating. The collected soil sample is then examined and tested to determine its properties, such as grain size distribution, plasticity, and shear strength. Lyöntikairaus is a relatively quick and cost-effective method, particularly useful in softer soils and where continuous sampling is not strictly required. However, it can cause some disturbance to the soil structure, and care must be taken to minimize this effect. The method is widely used in construction and environmental engineering projects to assess subsurface conditions.