System Research Of Surrounding Rock Mass Dynamic Classification In Highway Tunnel Of Construction State

The tunnel surrounding rock mass classification is the basis of its design and construction. At present, tunnel surrounding rock mass classification aims at the design phase by and large. And due to the limit of reconnaissance means, cost, time and so on, the tunnel surrounding rock mass classification at design phase is very different from the practical condition at construction phase. At construction phase, various geological problems exist, and more geological information can be attained, due to tunnel digging. With the general application and development of new Austria tunneling method, tunnel surrounding rock mass is required dynamic classification, modifying tunnel shoring design in order to instruct construction. According to the principle of informalization construction, the stability of highway tunnel surrounding rock mass is analyzed, and the dynamic classification research on surrounding rock mass at construction phase is carried out, by geological research, test, theoretical analysis, numerical analysis, on-site geological prediction and so on. In this thesis, the reliable indexes of surrounding rock mass dynamic classification are presented, and the system of dynamic classification is established based on the highway characteristics of big span and diameter-height ratio, severe force condition. The system is useful for the design and construction of highway tunnel.The main content and harvest are as follows:(1) The stability of highway tunnel surrounding rock mass is analyzed and researched completely.(2) The tunnel surrounding rock mass dynamic classification targets are presented, and they are quantified in parallel with six levels of surrounding rock mass.(3) With the extension theory, the system of surrounding rock mass dynamic classification is established, and the surrounding rock mass grade is quantified.(4) The prediction analysis model of the monitoring displacement information is established by using mathematical statistics regression analysis and grey theory model. The surrounding rock mass dynamic classification, the condition of shoring system, rational selection of shoring parameters and time are analyzed and appraised.(5) Take the Hougang Tunnel of the North-route ofZhejiang Wenzhou Round-city Highway for example. The dynamic classification research is carried out, and the stability of surrounding rock mass is appraised by monitoring.