碳纤维布用于深埋隧道衬砌裂缝的加固效果

为评价公路隧道衬砌裂缝的碳纤维布补强效果,同时为类似隧道工程提供加固措施依据,利用有限元软件对裂缝补强效果进行了详细的计算分析。通过现场检测某深埋长大公路隧道交叉口段二次衬砌的开裂状况,从地质构造学角度分析裂缝成因表明:衬砌开裂是由于围岩地应力侧压力偏大,侧洞开挖后导致衬砌应力重分布而产生向拉应力超过混凝土抗拉极限强度而产生局部开裂。基于有限元理论对隧道开裂段加固前后衬砌结构的应力场及位移场进行了对比分析,同时分析了碳纤维布的变形状况。结果表明,当二次衬砌开裂后将碳纤维布粘贴于衬砌内表面,由于碳纤维布参与承担荷载,对混凝土衬砌受拉变形起约束作用,碳纤维作为抗拉材料能有效控制衬砌裂缝的扩展。

Effect of lining crack treatment using carbon fiber in deep buried tunnel

T o ev aluate the ef fect of lining crack t reatment using carbo n f iber in a deep buried tunnel, and to establish an eng ineering basis for similar pro jects, the f inite element sof tw ar e w as applied to calculat ing the stain and the str ess in detail. By detect ing the cracks and analy zing the r easo ns of the l ining cracks o ccurred in a deep buried tunnel , the crack cause of the second lining w as obtained that the max imum tensile st ress w as beyond co ncrete tensile st reng th, w hich caused st ress redist ribut ion in ex cavat ion under surrounding- rock st ress and w eight . Based o n the finite element numerical analysis theo ry, the str ess f ield and the displacement field of the tunnel second lining befo re and after the reinforcement w ere calculated, and the deformat ion of the carbon f iber w as also analyzed. T he result show s that , because of the bearing load effect o f the carbon f iber past ing on the surface of lining cracks, the lateral defo rmat ion is r estr icted, and as a tensile resistance material, the carbon f iber can ef fect iv ely rest rict the widening