Performance Tests on Pressure-Dispersed Compression Anchors in Cohesive Soils

Abstract

Pressure-dispersed compression anchor consists of several anchor units fitted with an end plate. Limited field tests have been conducted to investigate the performance of a pressure-dispersed compression anchor system in cohesive soil. This paper conducted a series of field pullout loading test of pressure-dispersed compression anchors in clay soils, considering the following influence factors of stressing sequence, grouting method and compensation load. The simultaneous stressing yielded less pullout capacity than the individual stressing because of the relatively large interaction between the units. With the increase of the load level, the movement ratio decreased with a gradually decreased rate, followed by a slight increase when the load level exceeded 0.7. The rebound stiffness declined as the load level increased and the individual stressing yielded smaller reduction in the rebound stiffness than the simultaneous stressing. The back calculation indicated that the effective anchor diameter was enlarged by 10% due to the post grouting with a grouting factor of 0.2.