Soil improvement with a lateral tamping method

Soil improvement methods are required in soil where problems such as low bearing capacity, excessive settlement and liquefaction potential. Several soil improvement methods are used to improve geotechnical parameters of soil. Within this thesis, a novel lateral tamping method was presented as an alternative to mechanical improvement methods. The method is based on the principle of increasing soil density in lateral direction via a probe which pushed into standard borehole. The tamping probe converts the cyclic motion into tamping action along the lateral direction with the help of crankshaft. In this study, firstly, the properties of poorly graded sandy soil (SP) were determined, and various designs of the probe consisting of eccentric crankshaft, central distributor and other components were made, a prototype was printed out from a three-dimensional printer and steel products were produced. Large-scaled experimental studies were conducted in a cube-shaped test-cell to determine the effect of relative density and application spacing. After improvement at intervals of 3, 4 and 5 times the diameter of probe, the large-scaled plate loading tests and sand cone tests were performed on sandy soils with three different relative density values. Due to lateral tamping with 3D intervals, 30% of increment was achieved in relative density compared to the pre-improvement cases, plus an enhancement up to 6 times regarding soil bearing capacity. Finally, test boreholes were drilled in the field after the eccentric tamping probe had been adapted to the drilling machine. Consequently, an original, easy-to-apply, and nature-friendly mechanical soil improvement method was presented.