COMPARATIVE STUDY ON THE PERFORMANCE OF TYPE A AND TYPE B MICROPILED SYSTEMS IN SANDY SOIL UNDER VERTICAL LOADS FOR OPTIMIZING BEARING CAPACITIES

Micropiles are small-diameter drilled grouted piles. The grouting technique affects the connection between the grout and the surrounding earth. According to FHWA 2005, the most popular varieties of these techniques are Types A and B. For experimental work, these methods are the most appropriate. With an emphasis on the impact of the water-to-cement (W/C) and slenderness ratios (L/D) on performance, this study compares the bear-ing capacity behavior of Type A and Type B micropiles in sandy soil under compression loads. Also, a mathematical model was developed to predict pile load capacity based on settlement (δ), L/D ratio, and W/C ratio, providing a practical tool for optimizing pile de-sign. This research emphasizes the importance of geometric properties and grout compo-sition in enhancing micropile efficiency under various loading conditions. Based on the present study on Type A, experimental results show a load capacity (Q) reaching 6082 N at settlement (δ) of 5.08 mm for L/D=14 and W/C=0.3. Type B demonstrates higher ca-pacities, reaching up to 7848 N at a settlement of 3.8 mm under similar conditions. These findings indicate that Type A exhibits complex behavior influenced by slenderness and W/C ratios, while Type B shows a more direct relationship with settlement. The results provide valuable insights for optimizing micropile design and performance prediction.