Ring-shear test data of corundum sand “NKF120” used for analogue modelling in the experimental tectonics laboratory at GFZ Potsdam

This dataset provides friction data from ring-shear tests on corundum sand “NKF120” used in analogue modelling of tectonic processes as a rock analogue for “strong” or “high density” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016) or as an additive to PDMS silicone oil to increase its density and non-linearity (Zwaan et al., 2018). According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.75, µD = 0.57, and µR = 0.62, respectively (Table 5). Cohesion of the material ranges between 100-150 Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities. The tested bulk material consists of corundum sand with grain size of 90-120 µm (Table 1). Corundum sand is produced as industrial abrasive materials and sold e.g. by the company Nico Bosse Strahlmittel Berlin. The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany.本数据集提供了刚玉砂‘NKF120’的环剪试验摩擦数据。该砂可作为构造过程类比模拟的岩石类比物，用于模拟地球上地壳的“强”或“高密度”层（如Klinkmüller等人，2016年），也可作为添加剂添加到聚二甲基硅氧烷（PDMS）硅油中，以提升其密度与非线性特性（Zwaan等人，2018年）。经本研究分析，该材料表现出莫尔-库仑（Mohr-Coulomb）特性，其破坏包络线呈线性分布。刚玉砂的峰值摩擦系数、动摩擦系数与再活化摩擦系数分别为µP = 0.75、µD = 0.57及µR = 0.62（见表5）。该材料的内聚力介于100~150 Pa之间，且表现出微弱的速率弱化效应：剪切速度每变化一个数量级，摩擦系数下降约1%；同时在低剪切速度下呈现黏滑（stick-slip）行为。本次测试的散装材料为粒径90~120 µm的刚玉砂（见表1）。刚玉砂作为工业磨料生产，例如由德国柏林的Nico Bosse Strahlmittel公司发售。本数据集收录的摩擦数据通过环剪试验测得，试验设备为SCHULZE RST-01.pc（Schulze，1994、2003、2008），试验地点位于德国波茨坦亥姆霍兹波茨坦中心——GFZ德国地球科学研究中心的实验构造学实验室HelTec。