Study On Integrated Technology Of Dealing With Wuzhaoguan Underground River

To satisfy the needs of national economic development, railway speed has been increased in full swing. Railway line through adverse geological site can not be avoided, especially through karst and Underground Rivers in Karst regions. Karst treatment in karst areas has been widely used in project constructions. In the current underground construction process, draining, grouting, span and circling around are the commonly used methods at home and abroad to deal with underground rivers. As for Wuzhaoguan tunnel in Yiwan, because of the limitation of railway line as well as the special constraints of water environment, the conventional approach is unable to meet the need of engineering. The tunnel must pass through the underground river at the same time during the construction and operation the groundwater systems shall not be damaged."Integrated technology of dealing with Wuzhaoguan Underground River "was a result of researching on the whole process of field testing, on-site construction and the end examination. With the assistance of experts from all the parties, we obtained the following results:⑴Engineering geological conditions of the underground river hall must be fully studied. Double-grouting closure, lowing hydrodynamic flow gradient in the hall, forward-drilling approach and multi-joint grouting are performed. Forwarding duplication grouting can offset water erosion, reduce the wastage of slurry and at the same time achieve the effect of grouting;⑵Object detection and drilling examination are used to evaluate the grouting effect in the underground river water shutoff regional, which and provides a theoretical basis for the follow-up treatment of underground river;⑶Before the construction on the tunnel boring under-through the underground water, on both sides of the contourφ108 steel pipe grouting is applied for reinforcement so that to prevent the collapse during the excavation of the tunnel.⑷Steel pipe grouting is applied to reinforce the tunnel basement. a reasonable construction technology control effectively the settlement of the tunnel structure of the tunnel boring under-through the underground water and can ensure constructing and operating safely;⑸Monitoring and Measurement system is a guarantee for the deformation of tunnel boring under-through the underground water meeting the design requirements; ⑹The construction trouble of going directly under-through the large underground river for the Wuzhaoguan tunnel is successfully solved, which also provides a new approach for the construction in the similar geological conditions. At the same time we also successfully remain the groundwater circulation system, avoid affecting scenic environment of Wuzhaoguan and ensure the normal operation of water power stations in Wuzhaoguan.