内外温差对明挖隧道主体结构内力的影响研究

明挖隧道内外温差会使其衬砌结构产生附加应力,严重时会使隧道轴线方向的衬砌产生环向裂缝。通过对温度进行现场监测,获得工程实际内外温差,对其规律进行简要分析并将其作为有限元计算的温度边界条件;采用ANSYS进行有限元计算,考虑明挖隧道主体结构修建完成和回填完成两个阶段,对隧道内部温度低于外部温度、隧道内部温度高于外部温度以及无温差3种工况进行分析,得出温差对隧道结构应力的影响规律。

Influence of Internal and External Temperature Difference on Structural Stress of Open-excavated Tunnel

Additional stress may be generated by internal and external temperature difference in open-excavated tunnel,and circumferential cracks appear in tunnel lining along the axial direction where the stress is big enough. Internal and external temperature difference in engineering site is obtained by field monitoring to analyze the controlling factors,which are regarded as FEM temperature boundary condition. Finite element method calculation with ANSYS is employed to analyze the working conditions where the temperature inside the tunnel is below the external temperature,the temperature inside the tunnel is higher than the external temperature and there is no temperature difference with a view to the two stages of the completion of the main structure of the open-excavated tunnel and the completion of backfilling. As a result,the influencing law of temperature difference on structural stress is concluded.