Study On Method Of Sub-classfication Of The Surrounding Rock In Highway Engineering Tunnel Based On Cluster Analysis Of SPPS System

When determining the level of the highway tunnel surrounding rock in the current "highway tunnel design code"(JGD70-2004),recommended the BQ surrounding rock classification method,in which the level of the surrounding rock is divided into I~ VI,and design the supporting structure respectively.But the level of the surrounding rock may be afected by many factors in actual engineering.Such rough classification affecting the supporting structure design seriously,in order to research the surrounding rock more accurately,we neet to research sub surrounding rock classification.the rock stability of ?,? levels is studied by use of numerical methods.The saturated uniaxial compressive strength,the surrounding rock coefficient,surrounding rock [BQ] value was selected as sub classification indexs,then introduced the K-means clustering method of the SPSS cluster analysis method and collected on the spot of the rock sample data for analysis,determine the predicting method ofsurrounding rock sub classification ultimately.Through the research,the following main research results were obtained:(1)The number of clusters is determined,according to the clustering center of uniaxial saturated compressive strength,the surrounding rock coefficient,[BQ] value,? surrounding rock according is divided into ?,? and ? by the nature of the pros and cons,? class surrounding rock is divided into ?,? and ?,and calculate the the index limit of each sub level corresponding.(2)Through factor analysis,three indicators of the variance contribution rate,through the comparison of the three variance contribution rate,determine the weight of the three indicators.Subsequently,it is deduced that three indexes correspond to the three sub level weight function.In the end,the sub grade of surrounding rock is determined by the weight value and weight function value.(3)Through the analysis of monitoring data of ? and ? grade surrounding rock section,the difference of surrounding rock sub grade of ? and ? level is different,the general trend of the tunnel vault settlement and the surrounding convergence value is increasing in the construction process...