Tunnel Designing And Construcrtion Contermesure Using The Mining Method For Shallow Tunnels On The Condition Of Water-Enriched And Greval Layer

At present , city tunnels constructed by shallow-buried and blind digging method are still affected by geological conditions, structure section , topography and other factors, confined to limited application scope , especially all the city tunnels by the method almost under the condition that without water. On the contrary, generally the city tunnels' groundwater is high , groundwater is the key factor to decide the success or lost for the construction , but the great depth and large-scale precipitation will bring damage to the surround environment (such as settlement , underground water lost etc. ), and it will increase the cost. After took a series of accessorial construction measurement in some countries, they broaden the application scope, but the construction speed is still slow. In the future , we should make a research on more reliable assistant construction method , to spread the shallow-buried and blind digging method to more shallow-buried, large-scale , multi- stratum field application.In the paper, by the research under the condition that grit gravel stratum with more water , and to use the shallow-buried and blind digging method to construct a power tunnel in Chengdu, and make a relative research on under water treatment, stratum stability, settlement , tunnel structure stability and construction safety , it brings forward that base on stratum pre-reinforcement and pretreatment scheme;reasonable tunnel section , initial lining structure and permanent lining design parameters;reasonable tunnel construction order and method;construction control standard and Site-monitoring measurement system together with monitor basement and so on, all the above can direct the tunnel design and construction. At the same time, it also provides reference for the city tunnel application under the similar stratum condition.