The open cut method refers to a construction method that first the rocks (soil) of the part of the tunnel are all removed, the barrel and tunnel portal is built and then the tunnel is backfilled. The advantage of this method is that it is simple, rapid, economic and safe. It is chosen as the first excavation technology in the early stage of urban underground tunnel project.The disadvantage is that it may have larger impact on the surrounding environment.
The open cut method refers to a construction method that first the rocks (soil) of the part of the tunnel are all removed, the barrel and tunnel portal is built and then the tunnel is backfilled. The advantage of this method is that it is simple, rapid, economic and safe. It is chosen as the first excavation technology in the early stage of urban underground tunnel project.The disadvantage is that it may have larger impact on the surrounding environment.
(1) Geological surveying and mapping. (2) Exploration and sampling. (3) In-situ test and laboratory test. (4) On-site inspection and monitoring. Engineering geological mapping is the basis of geotechnical engineering investigation and is usually carried out in the early stages of the investigation. The essence of this approach is to use geological and engineering geological theory to observe and describe the geological phenomenon, analyze its nature and rules, and thereby infer the geological condition of the subsurface providing evidence for other investigation methods like exploration and testing. In sites that have complex topography and geological conditions, engineering geological mapping must be carried out. However, for sites that is of flat terrain, simple geological conditions and relatively small space, engineering geological mapping survey can be replaced by investigation. Engineering geological mapping is the most economical and effective way to know the engineering geological conditions. High-quality mapping work can be fairly accurately infer the subsurface geological condition and effectively guide other investigation methods.
