Interaction Effects of Sabzkuh Tunnel Excavation and Ground Water Resources: (Environmental Management Approach)

In this paper, hydrogeology and geology of Sabzkuh tunnel path and its environment has been reviewed, so as to anticipation of changes in the natural regime of underground waters and its impacts in springs resources after tunnel excavation with environmental management approach has been determined. For this purpose, different formation of tunnel path, faults and their permeability and potential amplitudes were recognized and categorized. From another perspective, water resources and springs of tunnel path were identified and hydrogeological boundary of tunnel path was determined to investigate interactions among tunnel excavation and underground water resources. According to these data, the tunnel path had been divided into two section: 1. High risk areas (Choghakhor region) 2. Low risk areas (Sabzkuh region). After tunnel mechanized excavation, changes of ground and geological complexity of studied zone and influx of mud along with abundance of water into tunnel caused cancelation of tunnel excavation despite all measures carried out for injection and reinforcement in risky area and capabilities of mechanized excavation machine. Following that, due to interaction to fault area of Sakiabad (Aloghareh), this fault had been dried in less than one week. Drying of Sakiabad spring had brought negative effects in terms of social, environmental and economical in the zone. Scrutiny of this factors and considering all parameters, the tunnel excavation had ceased. Reviewing studies and feasibility of all effected sections and with environmental management approach, combination of tunnel in Sabzkuh and water canal in Choghakhor section and change in the profile of path in order to reduce regional environmental impacts have been relatively considered.