Study on Damage Constitutive Model of Rock under Freeze-Thaw-Confining Pressure-Acid Erosion

Abstract

Aiming at the acid-etched freeze-thaw rock for geotechnical engineering in cold regions, chemical damage variables, freeze-thaw damage variables, and force damage variables were introduced to define the degree of degradation of rock materials, the law of damage evolution, the total damage variable of acid-corroded rock under the coupling action of freeze-thaw and confining pressure was deduced. The continuous damage mechanics theory was adopted to derive the damage evolution equation and constitutive model of acid-eroded rock under the coupling action of freeze-thaw and confining pressure. The theoretical derivation method was used to obtain the required model parameter expressions. Finally, the model’s rationality and accuracy were verified by the triaxial compression test data of frozen-thawed rocks. Comparing the test curve’s peak point with the peak point of the model theoretical curve, the results show that the two are in suitable agreement. The damage constitutive model can better reflect the stress-strain peak characteristics of rock during triaxial compression, verifying the rationality and reliability of the model and the method for determining the model parameters. The model extends the damage model of rock under the coupling action of freeze-thaw and confining pressure in the chemical environment and further reveals the damage mechanism and failure law of acid-corroded rock under the coupling action of freeze-thaw and confining pressure.

Research and Patterns of Rock Acid Pressure Corrosion Tests

“…Guo Jianchun used stereoscopic acid pressure technology to improve the development of deep-seated rock oil and gas [7] . Youliang Chen and Peng Xiao studied the damage constitutive model of rocks under freeze-thaw-confining pressure and acid erosion and found the damage evolution of rock under acid erosion and freezing-thawing and confining pressure, and derived the model parameters to reveal the reliability of the model [8] . Fanhui Zeng provided a method of acidifying rocks to reduce fracturing pressure, and the research results showed that acidification can reduce rock strength and critical stress intensity factor of cracks, thereby reducing crack pressure combination [9] .…”

Experimental Study on Damage Properties of Granites Under Flowing Acid Solution

“…Through triaxial rheological tests, Xie et al (2011) found out that chemical corrosion greatly accelerated the instantaneous strain rate of limestone under triaxial stress. Chen et al (2021) derived the damage evolution equation and constitutive model of acid-corroded rock under the coupling effect of freezing-thawing and confining pressure based on the theory of continuous damage mechanics and carried out triaxial compression test to further reveal the damage mechanism and failure law of acid-corroded rock under the coupling effect of freezing-thawing and confining pressure. Wang et al (2021) soaked the granite in nitric acid with different pH values and analyzed the mechanical properties of granite under corrosion acid and freeze-thaw cycles by uniaxial compression and freeze-thaw cycles.…”

Triaxial Compression Fracture Characteristics and Constitutive Model of Frozen–Thawed Fissured Quasi-Sandstone

“…In addition to experimental research, some researchers have also theoretically analysed and established a constitutive model of freeze-thaw damage for rock and analysed its damage evolution law [44]. Some scholars have combined the macroscopic static elastic modulus and microscopic element strength of rock [45].…”