Experimental study on cyclic simple shear behavior and thermal property of loess treated with nanosilica

Abstract

Nanomaterials are gradually appearing in the field of geotechnical engineering to treat problematic foundations and prevent landslides. The cyclic resistance strength and post-cyclic shear strength development of solidifying loess with nanosilica were investigated. The effects of nanosilica dosage and initial effective consolidation stress on the strength of treated loess were investigated through a series of cyclic direct simple shear and post-cyclic monotonic shear tests. Microstructures and crystalline phases of loess treated with nanosilica were analyzed by scanning electron microscopy(SEM) and X-ray diffraction(XRD) tests. In addition, the thermal conductivity of loess was tested at different water content and nanosilica doping. Based on the test result, it was concluded that the cyclic resistance and post-cyclic shear strength of loess increased continuously with the increase of nanosilica doping. Nanosilica solidifies loess through three mechanisms: filling, encapsulation, and reinforcing cementation, without chemical reaction with the soil components. On the other hand, nanosilica is an excellent thermal insulation material that can effectively reduce the thermal conductivity of loess.

Keywords

nanosilica / loess / cyclic direct simple shear tests / thermal properties