| The weak rock not only has the creep and machanical properties, but also has themechanical properties of anisotropic. In this paper, the diversion tunnel engineering ofShuipoxia, Xiergou,Chengzigou powper stations are regarded as background.Onaccount of the different angle of regional geological structure of the occurrence ofsurrounding rock, creep characteristics experiments of rock were developed as thechanges loading mainly direction of rock samples and the differences azimuth angles oflayer inside. On this basis, creep parameters anisotropy on the influence of the stabilityof surrounding rock under different inclination is studied through the results ofnumercial simulation and field monitoring. The main contents of the paper include:（1）The lithology of Bailongjiang basin is mainly made of quartz mica schist,sericite schist and picecs rock, such as in the diversion tunnel area of the Shuipoxia,Xiergou,Chengzigou power stations.The thickness of rock layer range from a fewcentimeters to dozens of centimeters.Strata inclination is about10°~70°(horizontalangle of existence in the transition section), and85°steep dip of approximate upright.The set of layered soft rock and driving shaft are intersection in all angles, which showcreep characteristics to become the main factors influencing the stability of surroundingrock.（2）Inthe studyarea, the size ofGround stress inthe surrounding rock hasto do withthe thickness of rock, the thickest overlying rock to be300-700m. So in the study in-situstresses of three power plants were inversed by finite element method on the basis of thefield ground stress. The inversion indecate that: the ground stress field research is higher,the results for numerical simulation providing reasonably tectonic stress inputconditions.（3）With the test of rock material composition identification and creep property ofdifferent inclination,the results showed that the occurrence of layer inside has majoreffect on creep strength, relationship curve between it strength and plane with dip angleis change of wavy the highest, the vertical bedding reached to be a maximum direction and shear creep’s long-term strength was the lowest. Maxwell modulus and viscositycoefficient, kelvin modulus and viscosity coefficient of creep parameters with verticalslices of compression creep~along the piece the compression creep~along the piece theshear creep being lessening. But the change trend of maxwell modulus and viscositycoefficient, kelvin modulus and viscosity coefficient were basiclly same to be wavy: theminimum of maxwell modulus and viscosity coefficient appeared about45°~60°,0°vertical loading appeared maximum, the minimum and maximum of Kelvin modulusand viscosity coefficient all appeared45°and0°. Accoring to change rule fitting outobliquity change equation with the creep parameters, it can converse other angle creepparameter values.（4）Integratedlyrock characteristics ofthethree power stationconducting a conceptmodel, deformation features of the software3DEC discrete element for differentinclination creep module of surrounding rock under the influence of excavation andsupporting the deformation characteristics were performed the numerical analysis.Through calculating, rock deforming toward surface after excavation with a certaindegree of springback, With angle of bedding face different, excavation displacementwere difference. When rock angle was0°or90°creep displacement to be the smallest, itwas between15°~75°creep displacement oscillation type to be increasing. For X and Ydirection monitoring curves, the maximum always respectively appeared30°~60°and15°or75°. Therefore, the occurrence of bedding face had an important influence on theoverall stability of rock and after supporting around the hole rock displacement valueObviously decreased.（5）The numerical simulation results of the stability of the selected power stations’hydraulic tunnel wall show that the calculated tunnel wall deformation characteristicswere obtained with the deformation monitoring data results. |
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