Scientific paper ID 2456 : 2024/1

The paper presents an ”in situ” tests of screw piles in clayey soils. Screw piles and helical anchors (piles) are used in the foundation of building structures, for tensile foundation, to strengthen slopes, etc. They are environmentally friendly - no concrete is added into the soil, no excavation is done, and the soil can be easily restored or reclaied after they are removed. Screw piles can be used in all types of soils, in the presence of groundwater, frozen soils and in difficult areas for building. Screw piles or also called screw anchors are tested with actual sizes as they are used in practice. The lengths of the test piles are from 0.50 to 1.50 m. At shallower depths, the winding of the piles into the ground is done manually with suitable equipment. The equipment is made specifically for the test. The entire test is conducted as a scientific experiment under a scientific project at the „Todor Kableshkov“ University of transport - Sofia. The paper gives the results obtained for the tensile stresses that the piles can bear. The types of cracks observed, the type and size of the damaged areas in the soil around the piles are shown. A tension dynamometer with a range of 10 tons was used to measure the tensile forces. The screw piles are pulled out with a truckcrane. Conclusions have been made from the studies carried out.