SEISMIC STABILITY ANALYSIS OF TUNNEL IN JOINTED ROCK MASS USING DISTINCT ELEMENT METHOD A DISSERTATION Submitted in partial fulfillment of the requirements for the award of the degree of MASTER OF TECHNOLOGY in EARTHQUAKE ENGINEERING (With Specialization in Soil Dynamics) by TEWODROS MULAT DESSALEGN x DEPARTMENT OF EARTHQUAKE ENGINEERING INDIAN INSTITUTE OF TECHNOLOGY ROORKEE ROORKEE•247 667 (INDIA) JUNE, 2006