Amir. Rabie far - M.SC. of geotechnical engineering, University of Islamic azad, Science and research hamedan branch
Hamidreza. Vosoughifar - Assistant professor, Department of civil engineering, University of Islamic azad, South tehran branch

The use of underground structures such as subway with considering the growth of population and the volume of traffic were increased.Regarding the seismic damages in underground structures, safety control and their functions during earthquake and afterwards have been interested by many researchers.In this research,optimal placement of smart sensors in soil around tunnel was evaluated.. In this way we can investigate the health monitoring of tunnels.The twin tunnels of shiraz’s subway has been chosen for case study.The plaxis finite element software has been chosen to carried out seismic response of tunnels and the nearby structures.The spss statistic software has been chosen to verify the results through past studies.To define fitness function the major and minor stress of output plaxis (s1, s3) has been used.The amounts of critical stress in major direction based on the minor stress of output of plaxis with used of hook brown formula was calculated. The difference the mentioned amounts defined such as fitness function then with genetic algorithm optimal placement of smart sensors was evaluated. Based on the conclusion, optimal placement of sensors show that surface structures in the saturated conditions have effected near field earthquakes in comparison with far field earthquakes which there is a significant difference between the obtained numerical results.

earthquake , tunnel , smart sensors