Utilization of Different Additives in Improving Sandy Soil against Liquefaction

One of the main risks in low-densified sandy soils with the presence of water and an external force such as an earthquake is the generation of liquefaction. The influence of several types of reinforcement on liquefaction resistance, such as polypropylene fibers, geofibers, cement and polypropylene fibers with cement is shown in this study. Cyclic stress-controlled triaxial tests and cyclic strain-controlled triaxial tests were performed on saturated samples with and without reinforcements under undrained conditions. Cemented specimens were prepared with cement contents ranging from 0% to 3% by weight of dry sand and then cured for 3 days. The lengths of polypropylene fibers are 10 mm and 20 mm, respectively. The fibers were mixed with dry sand– cement mixes containing 0.50% and 1.00% by weight, respectively. Geofiber specimens were prepared in various arrangements. It was found that the liquefaction improvement factor (LIF) increased when fiber content and fiber length increased. The addition of geofibers increased the liquefaction resistance, as the number of layers increased. The addition of 3%C+1%F provided the best liquefaction resistance in this study compared with other additives. Finally, the reinforcement with cement and fibers is crucial for liquefaction resistanceof bitumen mastic should be considered beside the asphalt mixture performance and the bitumen rheological behavior. KEYWORDS: Liquefaction, Shear modulus, Cyclic stress, Geofiber, Polypropylene fiber.