Study On Optimizing Design Of Full Circular Monolithic Lining Structure For Single-Track Railway Tunnel

The site investigation has shown that operating tunnel disease is serious, even dangerous to operation. Without considering the quality of construction, the changes of operating conditions and geological condition, the reason for this is the abuse of the structure and the lining quality by the common lining platform if we consider it only on railway tunnel structure. The standard drawing of composite tunnel lining for single-track railway tunnel is improved, and the concept of full-circular monolithic lining and some kinds of primary scheme have been given. The design schemes are proposed after studying the stability of surrounding rock, comparing technique economy and analyzing all kinds of primary schemes. Finally, construction technology and the mechanical equipment matching, such as formwork of full-circular monolithic lining for single-line railway tunnel, are studied and some suggestions are given.The followings have been paid more attention and some technical innovations have been introduced in the paper.1. There are disparities between the standard drawing used in home and abroad after surveying and studying the actuality of the tunnel design. For example, the base structure of tunnel has been regarded and the resilience of the base is improved for satisfying some particular conditions (such as high velocity) abroad. But the base of tunnel is not regarded in tunnel design, which cause tunnel disease. Hence, the optimized design for the standard drawing must be carried on.2. According to the rule of optimized design, structure shape of single-track railway tunnel is designed, then 7 kinds of schemes are brought forward. By comparing the stability characters of rock after excavated, the best stable section shape is found.3. The security of lining is compared by load-structure model which is used in tunnel design. It shows that the K near the channel of tunnel's base is lower, and most tunnel diseases arise here, which is in agreement with the survey result. The proposed optimized scheme can meet the requirement of safety degree. Moreover, the synthetically mechanicsperformance is also better than that of standard one.4. The platform and the construction technology for full-circular monolithic lining are studied. The platform can not only get rid of vertical joints lying in construction of railway tunnel, but also decrease the effects of lining construction on mucking and transportation. Thereby it can advance construction velocity and guarantee the quality of lining.Finally, the main conclusions, the problems, the technical innovation have been introduced and some opinion has been proposed in the paper.