Stability Research On Neighburhood Road Tunnel In Weak Surrounding Rock

Duo to complicated geological and topographical conditions in midwest of china, during constructing highway would face with lots of tunnel engineerings for the future. Because of topographical and special geological control, connection with line, special structure shape such as neighbourhood tunnel have to teem.Based on many research results about the design and construction method and reinfocing middle rock column of neighbourhood tunnel, study about the neighbourhood tunnel in coal stratum weak surrounding rock is still needed. According the condition of HongKouJie tunnel of PingHong highway, author set up eleven different spacing by numerical simulation software-FLAC. In the coal of weak surrouding rock condition, choose the reasonable interval and construction method of tunnel in IV and V grades surrounding rock. The main work and conclusions are as following:(1) Analyzing the physical and engineering mechanical characteristics, and the disadvantage effect on the stability of tunnelling; (2) Analyzing the effect of tunnel stability of different interval in having no support and having support, based on plasticity effect region and circumjacent displacement of tunnel mark certain the reasonable interval in IV and V grades surrounding rock; (3) Considering the coal of weak rock(main bast ) in tunnel digging, the parameters of rock having the weakening course, analyse and study the rule by numerical simulation; (4) According to the actuality of HongKouJie tunnel, having simulated by different surrounding rock grade and burying depth condition; (5) Aiming at the special character of coal seam, provide a set of construction method of preventing gas.