Research Of The Evaluation Method And Practical Application For Highway Tunnel Structure Disease Based On Rough Set And Grey Fuzzy Theory

Throughout the world,China has the largest quantity of tunnels and the fastest speed of tunnel construction.With the promotion of the Belt and Road Initiative,tunnel engineering has gradually become a bridge connecting our country and the world.However,because of the long operating time and the bad operating environment,tunnel structure diseases have been widely caused during the mass develoment of tunnel engineering.It has become a really important matter that how to accurately judge the healthy condition of tunnel structure and then repair the deseases in time.In present,there is no standard about tunnel structure healthy evaluation in the industry,most of the evaluation solutions are still based on experience and qualitative analysis.This thesis focuses on building the Grey-fuzzy model for evaluating the structure healthy condition of tunnels and then quantitative determines the healthy evaluation value so that the tunnel maintenance department can obtain some useful information.The main content of this article is as follows:(1)Introducing several division criteria and applied environment for healthy condition of operating tunnels.This thesis refers to division in “Technical specification for highway tunnel maintenance” as standard,based on which the 4-level system is accomplished,and by which,this thesis establishes the evaluation set V in comprehensive evaluation model.(2)According to index selection principle of multi-level fuzzy comprehensive evaluation,this thesis selects six primary indexs to form the index set U : lining crack,seepage,lining material deterioration,empty hole behind lining,lining deformation and peeling.Then,it determines the secondary indexs for each primary index.The thesis not only establishes the index system,but also determine the factor weight distribution based on rough set theory,for which the comprehensive evaluation index system has been built.(3)Refer to domestic and international standard,this thesis specifies each sub-index into 4-level healthy degree,by which the comprehensive evaluation system can be in one-to-one correspondence to the evaluation set V.This thesis calculates the healthy degree menbership and builds the fuzzy comprehensive evaluation matrix by taking advantage of Cauchy Distribution formula.(4)Expounding the related content of grey theory,using which the fuzzy comprehensive evaluation matrix can be transformed into grey correlation-fuzzy evaluation matrix,in which the membership value is replaced by grey correlation coefficient.Then,the healthy condition vector of operating tunnel can be obtained by multiplying the matrix and the factor weight distribution achieved above.And the final healthy grading result can be determined by uniformizing the vector.The feasibility of this model has been validated by applying it into project examples.