Program Development And Engineering Application Of Nishihara Model Based On FLAC^3D

Under the effect of long term load,the stress and strain of rocks vary with time,this property is the rheological property of the rock.The safety and stability of geotechnical engineering are related to the rheological properties of rock.It is very important for engineering to study the rheological properties of rocks.Nishihara model is the most commonly used model in geotechnical engineering,It can comprehensively reflect the rheological effect of rocks.,and it has been widely used in engineering practice.The Nishihara model and the ABH deep buried water conveyance tunnel project are the research objects in this paper,on the basis of previous studies,By using the method of theoretical analysis and numerical simulation,the differential form of the Nishihara model in three dimensions is derived.Use the interface of the constitutive model provided by FLAC^3D,compiling the Nishihara model into a dynamic library DLL file,and verify the correctness of the Nishihara model.In addition,using the Nishihara model,analy the stability of the surrounding rock of the ABH tunnel,the support time of different sections is obtained,and reasonable suggestions for the project are put forward.The main contents and results of this paper are as follows:?1?Combined with the rheological theory of rocks,the difference of the Nishihara model in three dimensions is obtained;the mechanical model and stress-strain relation of rock rheological basic elements are expounded in detail.At the same time,the basic combination mode and constitutive equation of the commonly used components are discussed,and the method for determining the rheological parameters of the Nishihara model is also analyzed;?2?Through the interface of the constitutive model provided by FLAC^3D,do the Secondary development of Nishihara model,and compiled into the dynamic library DLL file;By degenerating the FLAC³DD self-brought model,verified the correctness of the elastic and viscoelastic part of the Nishihara model;Through the inversion of the rock rheological test,Verified the correctness of the Nishihara model;?3?Using the Nishinara model,the excavation support scheme for III type surrounding rock and IV type surrounding rock tunnel in ABH tunnel project is studied.Through multiple trial calculations,given the timing of tunnel support,It provides reference for the project support scheme;...