The physical model tests of stiffened micropiles with similarity ratio of 1/7 are carried out. By using the pseudo-static test method in which the force control load and imposing load on the top of the micropile are used

the hysteretic curves

skeleton curves

the hysteretic characteristics

the bending moment and the failure mechanism of single stiffened micropile under circulating load are obtained. The tests results show that

the load-displacement lelation has the stable hysteresis loop and the characteristics of the stiffness degradation; the separation effect between the micropile and soil happened in the upper soil under the lateral cyclic load; and the atrophy phenomenon is found in the hysteresis curve; the bending moment of micropile mainly concentrated within the scope where the distance below the top of the pile is about 17 times diameter of micropile; and the maximum bending moment is located below the top of the pile with the distance about 6 times diameter of micropile .