Construction Technology of Single Side Drift Method for a Double-pilot Tunnel Eight-lane Highway Tunnel
In order to explore the mechanized rapid construction method for a double-pilot tunnel eight-lane highway tunnel under grade IV surrounding rocks,this paper,based on Chengzaishan Tunnel in the reconstruction and expansion project of Shenzhen-Shanwei Expressway,and combining the tunnel drilling and blasting method for excavation,adopted the field construction technology test,numerical simulation,theoretical analysis,field monitoring,etc.,and put forward the construction sequence and construction technology of the single sidewall heading method for grade IV2 surrounding rocks.Also,the rationality of the method was analyzed according to the settlement displacement and stress.The results showed that when the mechanized single sidewall heading method is adopted,the settlement increase is the largest after the left guide hole is backfilled,and this increase is 50%.After the excavation of the left pilot tunnel,the horizontal convergence decreases due to the excellent supporting effect of the middle wall,but it increases sharply with the excavation of the right pilot tunnel;The maximum tensile stress value of the feet-lock bolt is greatly impacted by the tunnel contour,and the maximum compressive stress value rises first and then tends to be gentle;The maximum tensile stress of shotcrete continues to rise and lies at the vault,but it decreases continually as the right pilot tunnel is being excavated;The maximum compressive stress of shotcrete lies at the arch foot of the upper step and it continues to increase in the processing.
double pilot tunnels and eight lanesmechanizationsingle sidewall heading methodconstruction technologyconstruction mechanics
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NSTL
万方数据
维普
