Abstract: There are two types of grouted, geotextile tube reinforced gravel columns: columns with or without steel reinforcement. The role of steel reinforcement is studied throughout the insitu loading tests. A total of eight columns are divided into groups with/without reinforcements for the comparative studies. The test items are: column integrity tests with low stress wave reflection method, unconfined compressive tests on grouted samples cored from the columns as well as vertical and horizontal loading tests on the single columns. The results indicate that the steel reinforcement has a positive influence on the column integrity and the introduction of grouting tubing simplifies the construction procedures. The steel reinforcement has limited impact on the axial capacity, but it has a significant impact on the lateral load resistance.

Key words: Grouted Geotextile Tube Reinforced Gravel Columns, Steel Reinforcements, In-Situ Tests, Column Integrity, Lateral Loading Tests