Large-scale biaxial experiments on frictionally heterogeneous faults: Mechanical data and selected strain and image data

Frictional heterogeneity within fault zones is one of the factors proposed to explain the spectrum of slow, intermediate, and fast slip behaviors exhibited by faults in nature. Numerical modeling shows how even a simplified model setup incorporating sliding on a velocity-weakening (VW) patch surrounded by velocity-strengthening (VS) material can reproduce a rich variety of slip behaviors resembling nature. However, experimental investigations of sliding on heterogeneous faults are few. In this study, the slip behavior of three, 347 mm long x 50 mm wide, heterogeneous experimental faults, constructed using diagonally sawcut PMMA forcing blocks, was investigated at low normal stresses (