Displacement Back Analysis Of Fractured Rock Masses Considering Damage Evolution

Today, in Rock and Soil Mechanics and Engineering, one of the biggest problems is to gain parameters of rock and soil materials. Uncertainty of parameters, shortage of data, mistiness of constitutive law, and serious nonlinearity has been a big obstacle to engineers. Meanwhile, in most cases of engineering, it has been proved that the fissured and jointed rock masses has dominated the majority of proportion, the mechanic behavior of which is also vital important for many professionals to study. Apparently no doubt, the parameters displacement back analysis of fissured and jointed rock masses based on damage theory is meaningful scientifically and practically. From this point of vision, the following four main parts have been given top priority in study.The first is to discuss the constitutive law of jointed rock masses and its damage evolutionary law, which is the footstone of the whole research job. And known to all, rock masses insi is a kind of jointed structure, and bear the character of anisotropy, nonlinearity, heterocomponents. And it's widely acknowledged that the elastoplastic model coupling damage can best suit for the jointed rock masses, and many scholars outdoors and indoors has fulfilled related work in mechanic test and theory pursuits, whereas without little breakthroughs. By giving deep insights of the former research results, the elastic coupling damage and plastic model has been set up, which is integrity in theory, simplicity in computation, and convenient in applying into the real projects.The second part deals with the numerical assimilating of the jointed rock masses. It is a hanging dilemma for almost all commercial FE or FD programs nowadays in that there is no coupling damage solver, which reflects on the stagnant development of damage theory study and appliance. According to the damage equivalent principle, such as stress equivalent, strain equivalent and energy equivalent, the second hand design by FISH language embedded in FLAC3D programs, is precisely adopted to calculate the coupling damage, at the same time, the excavation of rock masses, shotcrete, anchoring, and lining support been well modeled.The third part is at the core of the paper. The parameters problems arouse many concerns for years in rock and soil circle, and which stands out speciously in fissured and jointed rock masses. The hardness to get parameters, high costs, and low accuracy is far from the reality needs in engineering. Facing the difficulties, many researchers turn to the displacement back analysis which derives from reverse and feedback thoughts, and has been welcomed as an effective and economic way in resolving the problem. Based on the damage constitute and coupling damage iterating of fissured and jointed rock masses, constructing a type of hybrid simulated annealing algorithm...