A Study On The Secondary Development Of The Time-depedent Splitting Constitutive Model Based On ABAQUS

Along with our country the implementation of the strategy of "area",built in the infrastructure construction in our country vigorous development in the new period,the China water conservancy water and electricity facilities development and construction in southwest China.Due to the special geographical location,water resources and hydropower projects throughout southwest mountain area,so the water resources and hydropower projects in the underground engineering,with large buried depth,high complicated engineering geological conditions and ground stress,etc.Especially represented by jin screen level of hydropower stations,such as high walls surrounding rockmass because of its high ground stress-has the characteristics of low strength stress ratio in the cavern excavation unloading process will produce the nonlinear mechanical behavior of large deformation,the limitation of surrounding rock fracturing phenomenon.That under the condition of high stress produced by aging splitting phenomenon of the security and stability of the deep cavity consequences,affecting the construction of the engineering construction and normal operation,thus arouse great attention,many experts and scholars in the research field both at home and abroad through the model test,the theoretical study and numerical simulation on the comprehensive analysis methods,such as a large amount of research.Commonly used in numerical simulation,the nonlinear finite element analysis software ABAQUS,ANSYS,etc are widely used in geotechnical engineering field,but because of the complexity of the aging phenomenon of splitting mechanism of surrounding rock,in the finite element software without proper constitutive model for the accurate simulation analysis,therefore an urgent need to develop a suitable constitutive model,to provide reliable basis for the theoretical research and practical engineering construction.Finite element analysis software ABAQUS in strong nonlinear computing functions at the same time also has good openness,can provide users with targeted subroutine interface,allowing users to use ABAQUS platform for secondary development,improve the function of ABAQUS.This article will kam screen first-class hydropower station as engineering background,deep underground cavern excavation surrounding Zou Chen hao proposed in literature [1] of the limitation of the surrounding rock fracturing constitutive model is studied,using Fortran programming through the UMAT subroutine of ABAQUS software,developed for the limitation of surrounding rock of splitting constitutive model is analyzed,and compared with the experimental results in literature [1],the result is consistency,enrich the database of ABAQUS,provide a reliable basis for the research of aging splitting is revealed.The main research contents of this paper are as follows:(1)based on the research of the neutron program interface software of ABAQUS,the three user material subroutine in ABAQUS software user material subroutine(UMAT),user-defined subroutine(UEXPAN)and user-defined son program(USDFLD)used in this study the constitutive model secondary development;(2)based on the analysis of buried cavity due to high geostress caused high sidewall of surrounding rock in the process of excavation unloading time splitting phenomenon,on the basis of selecting aging splitting constitutive model in literature [1] as development object,in this study for the aging splitting constitutive model gives its incremental form,provide the basis for future programming;(3)the secondary development platform by using ABAQUS software,programming with Fortran,developed the limitation of surrounding rock fracturing UMAT subroutine of constitutive model,analysis of subroutines developed by using simulated and compared with the experimental data in literature [1],the subroutine correctly written verification;(4)the cavern excavation simulation USES the whole section excavation and a three-stage division of the excavation,analysis and comparison the cavern rock stress and strain under different excavation state features,further study on aging fracturing effect on the stability of cavern;(5)this article selects the marble aging splitting constitutive model can well reflect the high stress of surrounding rock under the condition of aging splitting phenomenon,using written constitutive model subroutine for deep cavity simulation of excavation unloading,and get the simulation results can well reflect the limitation of surrounding rock fracturing phenomenon,for deep water and electricity engineering geology and rock engineering stability study has important theoretical significance and practical engineering application value.