Taking Motianling tunnel in Chongqing as an engineering background, the monitoring and measurement scheme is proposed for the extra-long tunnel under complex condition, and the field data and the numerical simulation results is analyzed. The results indicates that, the selected cross-section reflect overall state of the Motianling tunnel, and the structure safety monitoring during operation is considered; by tunnel internal and external observation, it is found that the tunnel face in F22 fault zone may not stay stability, because the monitoring information receive feedback timely, and the supporting measures is proper, the surrounding rock stay stability when excavating; for the typical section, the surrounding rock contact pressure is greater than interlayer pressure, primary lining sustains most of the load ,and the secondary lining plays an assistant role as safety reservation; the maximum of anchor axial force and surrounding rock pressure occur at tunnel crown. By monitoring and numerical simulation, the dynamic excavation and design is realized, the Motianling tunnel is achieved safely and successfully at last.

To reduce the impact on water resource and the environment, the ‘controlled drainage principle’ is complied with when designing waterproof and drainage system of tunnel in recent years. For deep tunnel in Water-soaked Karst Stratum, the lining would sustain high water pressure that was caused by the unreasonable design of waterproof and drainage system. Taking a railway shield tunnel as an engineering background, the water shut-off effect of grouting circle, minimum controlled discharge of tunnel and the water pressure of lining properties were studied. The results indicated that, under the condition of high initial water pressure and adequate groundwater recharge, to achieve the desired water shut-off effect, the permeability coefficient of grouting circle should be less than that of surrounding rock over one quantitative grade; the water pressure of lining decreased with the increase of discharge, and showed a linear relationship; the lining could meet the requirement on the design water pressure load, when the permeability coefficient of grouting circle less than 1/20 of the surrounding rock’s, and the controlled discharge greater than or equal 1/2 of uncontrolled discharge; the full-sealing waterproof lining would sustain initial water pressure and the calculation value of water pressure couldn’t be discounted, if the grouting wasn’t waterproof.