Tensile micropiles are one of the anchor systems in soil. In general, micropiles are load-bearing elements with a small diameter (less than 30 cm), which is usually a combination of cement slurry and steel pipe with reinforcement. The performance of this anchor system in saturated sandy soils is often challenging if it is performed by pounding a perforated steel pipe in the soil and injecting it under the pressure of cement slurry (according to the common method in Iran). The escape of cement slurry from around the pipe and the lack of setting of cement in submerged soil conditions and as a result the reduction of anchor tensile bearing capacity are among these challenges, especially in coastal areas. In order to solve the challenges of micropile method in Iran, this study uses 2 new ideas (based on patents), including; the use of T-shaped and U-shaped spines in the body of steel pipes and the process of construction and implementation of barbed micropiles, tensile capacity analyzes and compares different types of micropiles.
The study site and pilot for construction and testing of tensile loading of various species of micropiles was in a coastal area of Deylam port at a distance of 500 meters from the Persian Gulf coast. To report the geotechnical studies of this experimental area, the study site consisted of a two-layer silty sand (SM) soil system with a thickness of 6 meter on clay (CL) with high thickness. The groundwater level was 0.5 meters above the natural ground level. According to the research program, 10 different types of micropiles with a length of 6 meters and diameters of 76 and 114 mm were performed with the aim of loading test and 20 micropiles of 12 meters on the sides of each micropile studied with the aim of creating a strong support for the reaction beam. After one year, the experimental micropiles were analyzed under tensile loading test and the load-displacement results of 10 different micropiles were analyzed.
The results show that the microp