• PDF / 7,183,064 Bytes
• 14 Pages / 595.276 x 790.866 pts Page_size
• 3 Downloads / 221 Views

DOWNLOAD

REPORT

---

ORIGINAL PAPER

Mechanical Properties of Acid‑corroded Sandstone Under Uniaxial Compression Shuguang Li1,2,3   · Yingming Wu1,2 · Runke Huo3 · Zhanping Song3 · Yoshiaki Fujii4 · Yanjun Shen5 Received: 1 July 2020 / Accepted: 23 September 2020 © Springer-Verlag GmbH Austria, part of Springer Nature 2020

Abstract Long-term exposure to chemical solutions can change the mineral composition and microstructure and may seriously affect the physical and mechanical properties of rocks. Therefore, to clarify the effects of long-term exposure and types of acids on the mechanical properties of rocks, and to develop the constitutive model of acid-immersed rocks, uniaxial compression tests were carried out on acid-immersed sandstone specimens. The sample weakened, and the brittle failure behavior became more ductile by the acid immersion to the aqueous solution of hydrochloric or sulfuric acids. The duration of the compaction stage of the stress–strain curve increased, that of the elastic stage decreased; the peak stress, elastic modulus, and Poisson’s ratio decreased, and the peak point strains increased with the acidity and the immersion duration. The brittle shear failure of the untreated specimen became more axial splitting type failure with acidity. The damage variable of the combined effects of chemical and stress was introduced, and a statistical damage model considering the compaction stage of the stress–strain curve was established based on the damage variable. The model well-simulated the experimentally obtained stress–strain curves of the acid-immersed specimens. Finite element models reflecting the characteristics of the acid-immersed sandstone were established based on CT images. Keywords  Acid-immersed sandstone · Mechanical properties · Constitutive model · CT 3D reconstruction · Numerical simulation List of Symbols D Damage variable of the sample under the combined action of chemistry and load DC Damage variable of the sample attacked by acid solution DC1 Damage variable of the corroded area DC2 Damage variable of the uncorroded area Dm Damage variable of the sample caused by loading * Shuguang Li [email protected] * Yanjun Shen 1



Post‑Doctoral Research Workstation, China Railway 20th Bureau Group Co. Ltd., Xi’an 710016, China

2



R&D Center of Plateau Tunnel Construction Technology and Equipment, China Railway 20th Bureau Group Co. Ltd., Xian 710016, China

3

School of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China

4

Rock Mechanics Laboratory, Faculty of Engineering, Hokkaido University, Sapporo 060‑8628, Japan

5

School of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China



E Elastic modulus E(ρ1) Mathematical expectations of ρ1 E(ρ2) Mathematical expectations of ρ2 F0 Weibull distribution parameter H CT number of the sandstone H1 CT number of the sandstone in the corroded area H2 CT number of the sandstone in the uncorroded area Hr CT number of the sandstone matrix. m Weibull distribution parameter ΔV V