THREE - D IMENSIONAL D ISTINCT ELEMENT ANALYSIS OF GROUND FISSURE D ISLOCATIONS ON SHIELD PIPEL INES OF OPERATIONAL TUNNELS ALONG XIAN SECOND SUBWAY L INE

The second subway line in Xian city crosses 10 ground fissures, and these ground fissureswill influence the safety of subway line. Using the three - dimensional ( 3D) distinct element code ( 3DEC) , a computational model is built. The effect of ground fissure dislocation on the shield p ipeline of running tunnel of subway is exam2 ined. The deformations and stresses under different dislocations of tunnel lining is obtained. The calculated results show that, If the dislocation is changed from 10 to 93 cm, the deformation will be changed from 0. 712 to 13. 99 cm, and the maximum deformation will occur at 35 to 36 m along longitudinal direction about 9. 5 to 8. 5 m distance to ground fissures. The maximum tensile stresswill be changed from 0. 65 to 18. 43Mpa, and the maximum com2 p ression stresswill be changed from 0. 611 to 16. 9MPa. The maximum deformation and stress zones are uniform. The findings can p rovide effective design parameters and scientific evidences for quantify the effect of ground fis2 sures dislocation on running tunnel of subway.