Study On Advanced Prediction And Dynamic Construction Technology In Tunnels

During the tunnel construction, due to the complicated geological conditions of surrounding rock and the limitation of tunnel survey and design, unfavorable geology such as faultage and cave are often encountered in front of excavation face, and often cause adverse geological disaster such as collapse and drainage in the local area during the tunnel excavation, cause major engineering accidents and large economic losses, delaying schedule of construction. Therefore, tunnel geological forecast during the tunnel excavation becomes very important. Geological radar has many strongpoints such as fast scanning, simple operating, light weight and high resolution, thus it is used extensively as a kind of common geophysical survey method. but it also has some problems, such as multi-solutions of geological radar image, mixed image of geological forecast. Geological sketch method is another kind of commonly used geological forecast method, and it takes up short construction time, simple equipment, without interfering with construction, good prediction effect for the entire tunnel, and provides complete geological material, but its forecast distance is short, and operators demands high geological theory.Geological radar and comprehensive geological sketch method two advanced prediction method, formed a kind of practical advance geological forecast method, i.e. to quality surface and combination of geological radar detection advance geological forecast, simple, say what, based on geological theory in geological radar detection methods for comprehensive advance geological forecast method. This method overcomes the former two each method's shortcomings, simple operation, almost don't occupy tunnel construction time. For example expounds the practical advanced prediction, and procedures and methods in the actual combination forecast excavation engineering geology condition comparing, explains the practical advanced prediction are essential and reliable.A lot of field geological radar advanced prediction results, summarizes the bad geological (cave, fault fracture zone, rich water, border in geological radar image face) the display in this law, and several common adverse geological disasters detailed clarify for example, practical comprehensive advanced prediction for future encountered similar tunnel leading typical geological disaster offer reference and basis.Taking long tunnel, for example, slope based on practical advanced prediction results, according to the surrounding rock classification practical sexual advance geological forecast influence, ahead of the surrounding rock level V dynamically divide with IV grade level, the proportion of surrounding rock III level increases, the proportion of surrounding rock is reduced, the overall improve the surrounding rock's grades, but because timely change of tunnel excavation support scheme design and construction, make more accord with or close to the actual, not only reducing engineering accident, and to reduce the cost for the project.