In addition, due to the large size and high strength of the unweathered mineral, such as quartz, feldspar, and hornblende, the weathered samples are extremely easy to break in the traditional sample-making process, such as the cutting method. As a result, the undisturbed weathered granite sample is very difficult to get. Compared with the integral structure of granite rock and fine-grained texture of granite residual soil, the interlocking structure of weathered granites with large particles is easier to be damaged in the probe drilling process for borehole specimens. With the development of rock weathering degree, the fissure of weathered granite evolved progressively and the structure developed from a massive texture to a cataclastic structure ( Irfan, 1996). It should be said that there is still an inadequate systematic and comprehensive cognition of engineering characteristics of weathered granites. However, the water and mud inrush disasters ( Liu et al., 2019) and ambient rock collapse in the tunnel, slope collapse ( Zhang et al., 2021), and other problems ( Cui et al., 2016) still frequently occurred in the process of engineering construction in weathered granite strata, which caused a large number of economic losses and serious casualties. In addition, the properties of weathered granites were compared with other geomaterials and any fruitful research results provide important new insights for reference. The research emphasis developed from the engineering qualitative classification ( Irfan and Dearman, 1978), the basic physical properties ( Lee, 1965), and the deformation/strength characteristics ( Lee and Coop, 1995) to the hydraulic/mechanical properties of unsaturated weathered granite ( Xiong et al., 2022), the microstructure distribution of the intact weathered granite ( Shang et al., 2015) and the relationship between the microstructure and deformation of weathered granite ( Li et al., 2020). To study the particular property of weathered granite, many studies have been carried out since the 1960s ( Lee, 1965). Therefore, the weathered granite is a special geomaterial, whose physical and mechanical properties are different from sedimentary soil and sand. In addition, the weathered granite is usually weak in cementation and easy to collapse in case of water ( Liu et al., 2019). The weathered granite particles are irregular in shape with large edges and corners. Due to its special genesis, the weathered granite is generally characterized by multiple fractures in structure and is easy to break. Weathered granite is the product of the physical and chemical weathering of intact granite left in situ ( Irfan, 1996), which is widely distributed in the world. According to the experimental results, a mathematical model of the relation between corrected standard penetration test (SPT) N ’ value and dynamic shear modulus was established, and besides, the variation range of dynamic shear modulus ratio of weathered granite in the study area was given, which may provide a reference for dynamic stability analysis of engineering in the study area. Besides, a comparison between the experimental results with the previous results from other researchers indicates that the dynamic shear modulus ratio of weathered granite in the study area exceeds the parameter range obtained from others. The maximum dynamic shear modulus of samples with higher weathering degrees is more sensitive to effective consolidation pressure. The samples with lower weathering degrees have higher dynamic shear modulus under the same effective consolidation pressure. The results show that the degree of weathering and effective consolidation pressure have significant effects on the small strain stiffness properties of weathered granite. To evaluate the small strain stiffness properties of undisturbed weathered granite, the circular computer numerical control (CNC) abrasive wire sawing technology was applied to weathered granite sample processing and a series of resonance column tests were carried out to study the effects of weathering degree and effective consolidation pressure on dynamic shear modulus of undisturbed weathered granite. 3Department of Civil and Environmental Engineering, Shantou University, Shantou, China.2University of Chinese Academy of Sciences, Beijing, China.1State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, China.Juntao Wang 1,2, Lingwei Kong 1,2*, Chengsheng Li 3, Bingheng Liu 1,2 and JunBiao Yan 1,2
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