Field Study of HPTRM Combined with Vegetation and Anchor to Protect Newly Excavated Expansive Soil Slope

Abstract

Anchor reinforced vegetation system (ARVS) comprises high performance turf reinforcement mats (HPTRM), vegetation and anchors. It is a new attempt to apply the system in expansive soil slope protection. The goal of this paper was to evaluate the effectiveness of ARVS in protecting newly excavated expansive soil slopes. The field tests on the bare slope, grassed slope and ARVS protective slope were carried out, including natural and artificial rainfall. During the test, the soil water content, soil deformation, and anchor axial force were monitored, and then the slope protection mechanism of ARVS was analyzed. It was found that ARVS can effectively protect expansive soil slopes compared with bare slopes and grassed slopes. The vegetation and HPTRM form a reinforced turf, and the anchors fix it to the slope surface, thus restraining the expansion deformation. The axial force on the anchor of ARVS includes frictional resistance and tensile force transmitted by HPTRM, which is maximum at the early stage of support. The neutral point of the anchor of ARVS moves deeper under atmospheric action, but the vegetation and HPTRM on the slope surface can limit this movement.