岩石抗剪强度参数的正态模糊数线性回归估计OA

The test values of rock shear strength usually have randomness,fuzziness and variability,which makes the shear strength parameters calculated by Mohr-Coulomb criterion uncertain.In this paper,through the direct shear test of limestone,it is found that with the increase of lateral stress,the average value of shear strength shows an upward trend,and the standard deviation of shear strength under the same lateral stress increases gradually,which shows that the discreteness of shear strength increases with the increase of lateral stress.The shear strength test data under the same lateral stress obey the normal distribution.This conclusion conforms to the Lyapunov theorem,so the normal fuzzy number is used to describe the shear strength interval under the same lateral stress.At the same time,it is concluded that the cohesion and internal friction coefficient obey the normal distribution through theoretical deriva-tion.Based on this conclusion and the principle of fuzzy least squares method,a normal fuzzy number linear regression estimation method is proposed to characterize the interval characteristics of rock shear strength parameters,and the goodness of fit evaluation index is selected to evaluate the performance of rock shear strength parameters characterized by this method.The results show that this method can accurately estimate the normal distribution interval of rock shear strength parameters and provide a new idea for the determination of rock shear strength parameters.