## 1 Introduction
For example, a stochastic DFN model was established based on the two-dimensional finite element method of rock failure process analysis (RFPA\({}^{\text{2D}}\)). The failure modes, strength, and deformation parameters (elastic modulus and peak strength) of fractured rock mass were studied by [PERSON] et al. [22]. Results showed that the fracture geometry parameters had a significant impact on the scale effect of the fractured rock mass. The effect of geometrical parameters of non-persistent fractures on the mechanical behaviors of the rock mass based on PFC\({}^{\text{2D}}\) software was studied by [PERSON] et al. [23] under uniaxial loading conditions. The results showed that the effect of random fractures on strength was greater than the effect of the deformation modulus. Amongst the fracture geometrical parameters, the fracture orientation had the most significant effect on the mechanical parameters of the rock mass. The distribution of fractures in nature is three dimensional and spatial. A 3D equivalent DFN model was proposed based on the three-dimensional rock failure process analysis (RFPA\({}^{\text{3D}}\)) software, and the scale effect and anisotropy of the fractured rock mass were analyzed by [PERSON] et al. [24]. Moreover, the effects of the geometry (orientation, duration, spacing, aperture, and step angle) of parallel fractures on the uniaxial compressive strength (UCS) and deformation modulus were statistically investigated based on PFC\({}^{\text{3D}}\) by [PERSON] et al. [25]. It was found that the fracture orientation had the greatest influence on the UCS and deformation modulus, followed by the fracture spacing. However, the fractures in the model were not random, which was not consistent with the actual project. The effect of fracture geometry parameters on the equivalent mechanical parameters of the fractured rock mass based on the 3 DEC software was studied by [PERSON] et al. [26]. The results showed that the elastic modulus was the most sensitive to the structural density and the UCS was the most sensitive to the trace length of the fracture. The estimation of the mechanical properties of fractured rock masses has always been a challenging task for practical rock engineers. A review of previous studies clearly showed that the fracture geometry parameters had a strong effect on the mechanical behavior of rock mass. The DFN model is an effective method to study the mechanical behavior of rock masses. However, the DFN model relied heavily on the quality of natural fracture structural data gathered in the field. The purpose of this paper was to evaluate the influence of fracture geometry parameters on the mechanical properties of rock mass using a combination of finite element methods and a fracture network model. First, the ShapeMetriX\({}^{3\text{D}}\) system was used to identify and extract the fracture geometry information in the dam site area of the Lianghekou Hydropower Station. The mean value, variance, and distribution types of fracture geometry parameters were obtained. Then, an orthogonal test scheme was designed based on the influencing factors and factor levels. The corresponding DFN models were established according to the fracture geometry parameters. The effects of fracture geometry parameters, including the inclination, dip angle, trace length and bulk density, on the UCS, elastic modulus, and failure pattern were studied under uniaxial loading conditions. Finally, the degree of influence of the fracture geometry parameters on the mechanical behavior of randomly fractured rock masses was statistically analyzed by using range analysis, variance analysis, and significance test.