Rheology Study Of Soft Rock And Its Impact On Slope Deformation

Taking guohua MuYin Indonesia coal project in non-working slope in open-pit coal mine as the research object, non-working slope is the longest open-pit coal mine slope, for the construction of coal mine safety and normal operation plays an important role. In this paper, on the basis of field geological investigation, indoor used to improved direct shear creep test instrument for clay, clay rock and mudstone in the load is 100 kpa, 200 kpa and 200 kpa under the conditions of direct shear creep test; For clay, mudstone Burgers was not using element combination rheological constitutive model was carried out on the experimental data fitting, Burgers was not get its rheological constitutive model; Burgers was not applied rheological element combination constitutive model fitting the constitutive model of clay and shale, and using numerical simulation software FLAC3 D to Indonesia MuYin non-working slope in open-pit coal mine using Mohr coulomb model and Burgers was not mixed the rheological model of calculation model of slope were analyzed. To do a thorough research on the stability of non-working slope. Research results are as follows:(1) clay, clay rock and mudstone in the low level of normal stress and shear stress under the action of the low level, creep deformation properties are not obvious, mostly in a few hours to reach to more than ten hours time deformation stability, and the deformation is small; As the shear stress level increases gradually, creep deformation has increased gradually, and at the same time appear attenuation creep and non stable constant creep phenomenon, the greater the shear stress level, to achieve the longer time is needed to stabilize the shear strain; As the shear stress continues to increase, increases to a certain value, the sample will be shear failure, and a very short time.(2) clay, clay rock and mudstone under the condition of certain normal stress, along with the shear stress level increases gradually, clay, clay rock and mudstone samples direct shear creep curve gradually from the attenuation creep to the constant creep and accelerated creep development, obvious creep of instantaneous deformation, constant creep and accelerated creep three stages.(3) the normal load, the greater the sample direct shear creep always in geotechnical engineering should be the more variables; The shear strength, the greater the sample direct shear creep in geotechnical engineering total should be the more variables; Shear stress level is lower, sample direct shear creep in geotechnical engineering should be variable to achieve stable the shorter the time; The higher shear stress level, sample direct shear creep in geotechnical engineering should be the longer the interval of reaching stability state of a variable.(4) the shear stress level classification, the more observable accelerated creep phenomenon more obvious, when shear stress level in more than one definition of value, the shear test piece in a very short period of time. But the corresponding shear stress level classification, the more the longer the test time is needed for consumption. When shear stress level is low, less hierarchical, shear stress level is larger with the increasing density of classification.(5)Burgers was not the components combined rheological model of clay direct shear creep test data fitting, clay and shale the normal stress at different levels and Burgers was not under the different shear stress level of rheological constitutive model of clay and shale and calculate the direct shear creep limit.(6) the stages maximum principal stress and minimum principal stress is basically a strip evenly distributed; Maximum principal stress in the third stage, the fourth and fifth phases after excavation, along the site to help lower part of the distortion, the local stress increase phenomenon; The minimum principal stress in the rheological numerical results using rheological constitutive model block area appear along the distribution of stress, high level; Along the site to help lower part of the negative shear stress and shear stress, high; The fourth and fifth phases after excavation, in a larger slope Angle position of shear stress, high;(7) on the rheological constitutive model block interface position, Xdisplacement along the level of distortion, and the displacement increases; Using the rheological constitutive model block interface in rock mass under X-displacement value almost the same; Using the rheological constitutive model block in the excavation surface appearance of X-displacement increases. After each stage of simulation of excavation, excavation face the following affected by unloading effect of rock and soil mass produce upward Z-displacement, and the rheological results in excavation surface generated by the springback value and the conventional calculation results are basically identical; Site along the help, rheological results Z-displacement were greater than the conventional calculation results.(8) with each stage of the simulation results, the rheological results and normal calculation results show that the rheological constitutive model under the block boundary of rock mass, the maximum principal stress and minimum principal stress and shear stress distribution difference, the two plastic zone distribution location calculation results are similar; Plastic zone distribution area is mainly as follows: in the mudstone and fine sandstone rock formation in the slope body part, internal shear stress concentrated area, slope excavation face the following newly exposed rock mass after excavation. Along the site to help in the rheological numerical results for not into plastic state, while the conventional calculation results for local in plastic state or ever into plastic state.