Study On Rheological Theory Of Engineering Soft Rock And Its Support Method

Rheological property is an important part of the study on rock mechanical properties,the rheological property is more significant to the weak rock mass,many engineering problems are closely related to its rheological properties,in slope engineering,underground engineering,and other rock engineering,studying the rheological properties of soft rock,especially the creep characteristics,and revealing the creep process and its rules,have great practical significance for engineering's design,construction and maintenance. On the basis of a series of previous rheological study,this paper implements more in-depth study on mudstone in Gao Jialiang mine shaft mudstone,Erdos,Inner Mongolia,and puts forward the feasibility recommendation for the support measures of shaft.Conventional uniaxial compression tests of rock is often able to determine reasonable loading level for the rock rheological tests,it determines the loading level of uniaxial loading and unloading creep test by Conventional uniaxial compression tests,simulates loading and unloading creep curves by unified theory of rheological models,establishes the elastic - viscous - viscoelastic - plastic rheological constitutive model and calculates the model parameters,the model that is established can simulate the loading and unloading creep of mudstone well.Because the researched mudstone is in the zone of hign latitudes,the temperature changes obviously,so,it is essential to study the creep properties of mudstone under the conditions of different temperatures. The triaxial creep tests of the artificial mudstone samples is implemented by a "cool box - triaxial pressure chamber" light test equipment system,the rheological constitutive equation of mudstone is established;in many rock projects, including underground,rock slope and rock-based projects,the load or surrounding rock stress often increases or decreases step by step with the construction schedule or program,the stage loading triaxial creep test of purple mudstone is implemented by the self-developed gravity lever creep testing machine, and equipped with triaxial pressure chamber and is simulated by H/M model, the parameters fitting of the model's creep equation under the three-dimensional condition by nonlinear regression analysis of MATLAB,the experimental curves and the theoretical curve have high degree of agreement,the maximum error is about 2e-5.That the damage mechanics is introduced into the study of rock mechanics is hot spot of the rheological mechanical properties of rock in recent years. On the basis of the triaxial creep tests,a damage variable that is defined by the method of time functions characterizing the creep damage variable of rock is introduced into the creep equation of AD model,the model parameters are determined by the method of polynomial regression Indirect solution rock rheological mechanical parameters,simulation results are very satisfactory,the third stage of the creep characteristics of mudstone were able to be showed,and the influence of different parameters on the creep curves is analyzed and juxtaposed. Through a series of front study on rheological behavior,the rheological deformation properties of mudstone are obtained,the deformation properties of mudstone is applied to the support of Gao Jialiang mine shaft, according to the theory of suspension,shotcrete net support is adopted,the proposed support method is compared to the practical support method through the use of ADINA software,which provides reasonable assessment and recommendations for the long-term stability and security of soft rock engineering.