Experimental Study on Mechanical Properties and Deterioration Mechanism of Red Sandstone from the Panjiatuo Landslide under Action of Acidic Drying−Wetting Cycles

Due to frequent water level fluctuations and complex hydrochemical environments, rock slopes in reservoir areas progressively deteriorate become unstable. This study investigated the coupling effect of drying−wetting cycles acidic solutions on physical mechanical properties, strain field evolution, failure mode, micro-mechanism red sandstone using a series laboratory experiments (wave velocity tests, uniaxial compression digital image correlation method, scanning electron microscopy, X-ray diffraction). The results showed that with increasing cycles, mass, P-wave velocity, elastic modulus, compressive strength decreased monotonically, while absorption apparent localization band increased. Moreover, mode transitioned gradually from tensile shear or tensile-shear composite failure. decrease solution pH values aggravated changes parameters contributed an increase secondary cracks occurrence behavior. In addition, accelerated worsening microstructure dissolution minerals, resulting loose structure well-developed pores fissures. These provide favorable explanation for property deterioration subjected cycles.