Deformation Analysis and Control Technology of Surrounding Rock in FenshuilingTunnel
Aiming at the problem of excessive deformation of surrounding rock in Fenshuiling Tunnel,the causes of deformation are ex-plored through modeling analysis and combining with the field data.Meanwhile,some measures to control deformation such as reserving longitudinal deformation joints and improving the support mode are put forward.The treatment results show that:(1)the rock mass near the regional geological structure is extremely broken and formed fault tectonic rock.The rock mass has the weak expansion property,and the expansion force is formed after water encounter.Under the combined action of groundwater and in-situ stress,the initial sup-port of surrounding rock is deformed.(2)Field monitoring results show that after the implementation of relevant control measures,the maximum settlement of surrounding rock vault is 17 mm,and the maximum convergence of surrounding rock vault is 11 m.In the end,the lining does not appear too large deformation,concrete fall,etc.,indicating that the control measures are more effective.(3)Com-pared with the original excavation step without pre-support,the arch settlement,arch foot convergence and arch bottom rebound values of the corresponding monitoring points decreased by92%,91.5%and83.7%,respectively,when the excavation progress was 2.4 m and the small pipe pre-grouting support was carried out.From the perspective of deformation,The best working condition control measures are the excavation progress of 2.4 m and pre-grouting support of small pipe.
tunnel engineeringsurrounding rock deformationnumerical simulationfield monitoring
NETL
NSTL
万方数据
