Vol20 No.8:2388-2404

【Title】Strength prediction model for water-bearing sandstone based on near-infrared spectroscopy

【Author】ZHANG Xiu-lian^1,2; ZHANG Fang^1,2; WANG Ya-zhe^1,2; TAO Zhi-gang^1,2; ZHANG Xiao-yun^3,4*

【Addresses】1 State key laboratory for Geomechanics and Deep Underground Engineering, Beijing 100083, China; 2 School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China; 3 Collaborative Innovation Center for Prevention and Control of Mountain Geological Hazards of Zhejiang Province, Shaoxing University, Shaoxing 312000, China; 4 Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province, Shaoxing University, Shaoxing 312000, China

【Corresponding author】ZHANG Xiao-yun

【Citation】Zhang XL, Zhang F, Wang YZ, et al. (2023) Strength prediction model for water-bearing sandstone based on near-infrared spectroscopy. Journal of Mountain Science 20(8). https://doi.org/10.1007/s11629-022-7796-5

【DOI】https://doi.org/10.1007/s11629-022-7796-5

【Abstract】The strength of water-bearing rock cannot be obtained in real time and by nondestructive experiments, which is an issue at cultural relics protection sites such as grotto temples. To solve this problem, we conducted a near-infrared spectrum acquisition experiment in the field and laboratory uniaxial compression strength tests on sandstone that had different water saturation levels. The correlations between the peak height and peak area of the near-infrared absorption bands of the water-bearing sandstone and uniaxial compressive strength were analyzed. On this basis, a strength prediction model for water-bearing sandstone was established using the long short-term memory full convolutional network (LSTM-FCN) method. Subsequently, a field engineering test was carried out. The results showed that: (1) The sandstone samples had four distinct characteristic absorption peaks at 1400, 1900, 2200, and 2325 nm. The peak height and peak area of the absorption bands near 1400 nm and 1900 nm had a negative correlation with uniaxial compressive strength. The peak height and peak area of the absorption bands near 2200 nm and 2325 nm had nonlinear positive correlations with uniaxial compressive strength. (2) The LSTM-FCN method was used to establish a strength prediction model for water-bearing sandstone based on near-infrared spectroscopy, and the model achieved an accuracy of up to 97.52%. (3) The prediction model was used to realize non-destructive, quantitative, and real-time determination of uniaxial compressive strength; this represents a new method for the non-destructive testing of grotto rock mass at sites of cultural relics protection.

【Keywords】Water-bearing sandstone; Near-infrared spectroscopy; Saturation degree; Uniaxial compressive strength; Prediction model; Dazu Rock Carvings