Ring shear test data of quartz sand and colored quartz sand used for analogue modelling in the Laboratorio de modelización analógica, Universidad de Zaragoza, Spain (EPOS TNA call 2017).|地质模拟数据集|材料力学数据集

This dataset provides friction data from ring-shear tests (RST) on different types of quartz sand used in the Laboratorio de modelización analógica of the Universidad de Zaragoza (UZ, Spain) as an analogue for brittle layers in the crust or lithosphere (Izquierdo-Llavall & Casas-Sainz, 2012; Calvín et al., 2013; Pueyo Anchuela et al., 2016; Peiro et al., 2018; Pueyo et al., 2018; Izquierdo-Llavall et al., submitted). The materials (quartz sand, green coloured quartz sand mixture, black coloured quartz sand) have been characterized by means of internal friction coefficients µ and cohesions C as a remote service by the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Friction coefficients of the pure quartz sand and the green quartz sand mixture are similar (µP = 0.74 – 0.76, µD = 0.56 – 0.60, µR = 0.61 – 0.64), whereas friction coefficients of the black coloured quartz sand are lower (µP = 0.48, µD = 0.39, µR = 0.45). Cohesions of all sands range between 40 and 150 Pa. A minor rate-weakening of ~1 % per ten-fold change in shear velocity v is evident. The tested materials are quartz sands with a grain size of 0.063 – 0.4 mm and bulk densities of ρ = 1610-1800 kg m^-3. The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at the Helmholtz Laboratory for Tectonic Modelling (HelTec) of the GFZ German Research Centre for Geosciences in Potsdam. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures and shear velocities similar to sandbox experiments.