Micropiles have been used for underpinning existing foundations founded on problematic soil, disturbed by the intrusion of underground activities (such as tunneling), or subjected to additional loads (such as stories added to existing buildings). This paper presents a field study on the behavior of single micropiles in soft clay subjected to compression or tension. Two compression and two tension loading tests were conducted on four single micropiles. All the micropiles were instrumented with rebar strain gauges, and they were monitored during the progress of loading. To set up a baseline for underpinned loading tests presented in a companion paper, a full-scale loading test was performed on natural soil. The results from all these full-scale loading tests are presented and analyzed in this paper. The paper discusses loaddisplacement responses, elastic moduli, axial forces, tip resistance, and skin friction relating to micropiles and their interactions with soft clay. Theoretical solutions for bearing capacity of soil, load capacity of piles, and percentage of tip resistance to the total load were adopted for examination of the test results.Key words: micropile, loaddisplacement, load capacity, skin friction, tip resistance.
Full-scale loading test on the reinforced embankments with geotextiles
