The Study On The Forecast And Countermeasure Of Great Distortion Of Highway Tunnel Wall Rock

Based on extensive information collection of great wall rock distortion models and their related research of a good number of tunnels and underground engineering at home and abroad, the thesis presents the definition and classified system of great wall rock distortion, builds a method system used in complex forecast of great wall rock distortion, discusses the thoughts of supporting engineering countermeasures of great wall rock distortion. The forecast system and supporting countermeasures have been carried out successfully at ZHEGUSHAN tunnel and ERLANGSHAN tunnel. The research results mainly include as follows:(1) Great wall rock distortion is defined. Based on the analysis of great wall rock distortion models of a good number of tunnels and underground engineering at home and abroad, the concept concerning the theory research and engineering practices of great distortion is a matter of confusion. The author defines the great distortion as those damages except brittle damages of rock blasting movement and collapse confined by a certain constructional surface in wall rock flexible circles. It is a kind of plastic distortion damage with the character of progression and obvious time effect. In this way, plastic distortion damage—great distortion, wall rock brittle damage—rock blasting and collapse confined by a certain constructional surface in wall rock flexible circles can be divided clearly.(2) The thesis presents classified principle and system of types and mechanism of great wall rock distortion of tunnel engineering. According to the controlling conditions, great wall rock distortion is divided into three big types of Hthology controlling type, rock structure controlling type and human action influencing type, eight small types and four hypo-small types. Attention has been paid to the great distortion caused by underground exploitation and surface environmental change. The mechanism of great wall rock distortion mainly includes nine types. The classification of types and mechanism provides reference for forecast and engineering countermeasures of great distortion.(3) The thesis builds an applicable method system of great distortion forecast through the combination of wall rock geology analysis, geology follow-up investigation, stress field tests, numerical simulation analysis, and wall rock displacement inspection, mechanism and trend analysis. The forecast system has been carried out successfully at ZHEGUSHAN tunnel and ERLANGSHAN tunnel. It can be used in great distortion...