The Methods Of Surrounding Rock Classification And Their Application In The Expressway Tunnel Of Mountainous Area

Tunnel engineering has been being the key engineering in the construction of expressway in mountainous area. Tunnel surrounding rock classification is the basis of design and construction, it plays a very vital part in tunnel engineering. However, the qualitative surrounding rock classification criteria in Code for Design of Road Tunnel(JTJD70-2004) is macroscopical, so it doesn't bring into instructional play. Although its quantificational classification method is convenient, it should be take quickly acquiring way for index based on the facts of tunnels. Therefore, it is very important to build methods and criteria of surrounding rock classification adapted to practice and uses in the construction of road tunnel.Based on the tunnels in Xipan & Pantian expressway and considering other's research, the paper takes the means of laboratory test and surveys on the spot,quantitative analysis and qualitative analysis, and detailedly studies the index system and methods of surrounding rock classification in the construction of expressway tunnels. The paper contains much peroration as follows:(1) It is established that the index system of surrounding rock classification and their quickly acquiring way in the construction of expressway tunnels through many methods contrastive analysis. The quantificational indexs mainly contain rock rebound,rock point load,RQD,fracture characteristic parameter(k) and the factors of underground water,structural plane occurrence and geostress.(2)Through experts survey,schemes establishment and applications feedback, it is established that the qualitative surrounding rock classifications for sedimentary rock,igneous rock and metamorphic rock tunnels, and it is suggested that the Q system could be adopted to quantificational preliminary classification and the BQ system could be adopted to quantificational detailed classification.(3)The fuzzy inference systems of surrounding rock classification for sedimentary rocks,igneous rocks and metamorphic rocks are established by way of fuzzy logic inference workbox in Matlab. These systems take the facts of surrounding rock classification in different conditions into consider, so they can infer surrounding rock rank reasonably. And the methods of surrounding rock classification for sedimentary rocks, igneous rocks and metamorphic rocks is also made by VLBP&MOBP neutral network(4)A surrounding rock intelligent classification program in the expressway tunnel of mountainous area is developed by Delphi language of OOP. The program contains two sub-systems, the one is surrounding rock classification based on Code for Design of Road Tunnel(JTJD70-2004), the other one is surrounding rock classification based on methods in the construction of tunnels.