Abstract:On the basis of the “casingcement sheathformation” system, the three dimensional finite element model was built. With this model, and under the nonuniform stress conditions, the stress change characteristics before and after the borehole drilling were studied and the effects of the changes of the elastic modulus of the rock,cement and sonde casing, the Poisson ratio, the cement thickness and the expansion coefficient of the system on the component strain and plane strain after drilling were inquired as well. The results indicate that the influence incidence from the borehole drilling is probably 1.5 times as big as the aperture. The influence of each parameter’s change on the strain is different, whereas the component strain response trend to the exterior load is primarily alike. Otherwise, under the uniform stress conditions, the effect of the cement thickness on the strain is related to the cement elastic modulus,but the plane strain is of negative correlation with the expansion coefficient
Li Yujiang,Lu Yuanzhong,Chen Lianwang et al. NUMERICAL SIMULATION OF AFFECTING FACTORS ON BOREHOLE STRAIN-METER OBSERVATION[J]. jgg, 2011, 31(1): 34-38.