| HeLanKou rock paintings belong to the immobile and permanent exposed to outdoor stone relics. Due to the natural environment and the activities of animals and plants, that causes the serious damage, including damage on the surface, weathering denudation and the unstable rock mass. In this paper, the HeLanKou rock paintings taken to be the research object. Firstly, on the basis of investigating the rock paintings area, the analysis and determination of the basic microscopic characteristics and physical properties of the rock material have been done. Thereby, the rock density, porosity, water absorption, and content of each component elements, the microstructure of the rock samples have been obtained; Through the indirect tensile test (Brazilian splitting method) and the uniaxial compression test, the conventional triaxial compression test and direct shear test, firstly the mechanical parameters and the characteristics of deformation and failure model of the HeLanKou rock semples been obtained; Through the stability analysis of typical unstable rock mass near the rock paintings area, "Donkey Sheep Figure", "Fingerprint Figure" and "Rock Slope Rock Paintings", we have obtained the conclusion of the unstable rock mass stability.The results show that:(1) the density of rock sample is higher, porosity and the bibulous rate is low; Element content of O and Si element is the highest. It is concluded that rock samples is mainly detrital quartz; The weathering phenomenon of rock samples without processing the surface is obviously. The particles on the surface of sample arrangement is irregular, and structure is scattered, and micro fracture is more; But the particles of the core drill rock sample configuration is relatively uniform. Fracture is not obvious, and also the mechanical strength is relatively higher. (2) Through the indirect tensile test (Brazilian splitting method), uniaxial compression test, the conventional triaxial compression test and the direct shear test, we obtain the average tensile strength of rock sample is 5.6 MPa, and the uniaxial compressive strength of 190 MPa, the Poisson’s ratio 0.286. The average elastic modulus is 42.99 GPa. The cohesive force and Angle of internal friction values are 40.66 MPa and 48.22°respectively. The experiment results verifier the microscopic characteristics of rock material high strength prediction. The triaxial compression stress-strain curve been obtained through the triaxial compression test. The curve can be divided into four stages, namely the elastic deformation stage, plastic stage, failure stage and residual strength stage. The correlation coefficient R2 of the shear strength curve, shear stress and vertical stress curve is 0.9861. (3) Through the stability analysis of the three typical unstable rock mass: "Donkey Sheep Figure", "Fingerprint Figure" and "Rock Slope Rock Paintings", we have found that in addition to the state of the "Rock Slope Rock Paintings" unstable rock mass is not clear, the others are in a safe condition. The research results can provide data support to the protection work of the HeLanKou rock paintings in this paper. |
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