Mass concrete

[1246] ANALYSIS OF HOOP STRESS GENERATED AT CROWN OF LINING CONCRETE IN NATM TUNNELS

Chamila K. RANKOTH¹, Akira HOSODA², Satoshi KOMATSU² (1.Yokohama National University 2.横浜国立大学)

Keywords:NATM, concrete, second lining, longitudinal cracking, stress in hoop direction, NATM, コンクリート, 二次覆工, 軸方向ひび割れ, 周方向応力

Stress generation at the crown in the second lining concrete of NATM double shell lining systems was studied using a finite element based system. The results of numerical simulation were compared to actual tunnel measurements in a past research. It was revealed that before the form removal, stress generation in the hoop direction leading to longitudinal cracking was governed by temperature variations. After the form removal, stress behaviour was governed by both self-weight and temperature decrease.