板式构件加固衬砌裂缝的模型试验研究

Study on reinforced cracking lining of plate members by model test

为了得到板式构件对隧道衬砌裂缝的加固效果,采用模型试验方法,对带裂缝衬砌加固前后的力学特性进行研究。通过对衬砌加固前后位移、接触应力、结构内力和破坏形态的考察,得研究成果:隧道产生裂缝后,发生位移早且位移量增大、承载能力降低,并将衬砌的破坏由墙脚压溃转变为裂缝处拉裂;通过板式构件加固后,产生变形较晚且位移量减小38.5%,板式构件有效的改善整个结构的受力状态并阻止裂缝的发展,显著提高了整体结构的抵抗变形能力和承载能力;既有衬砌承担的轴力占合力的73.9%,其仍然是加固后组合结构的承载主体;若采用合适的板式构件进行加固,其承载力完全可以恢复到甚至超过完好衬砌的水平。

In order to study the reinforcement effect of the plate members on the lining cracks,The mechanical properties of the crack lining before and after reinforcement were studied by means of model test. Through the investigation of the displacement,contact stress force and failure mode of the lining before and after reinforcement,the research results showed: After the cracks are generated in the tunnel, the displacement occurs early and the displacement increases,the carrying capacity decreases,and the damage of the lining is reduced from the footwall crushing to the crack. After the plate member is reinforced,the deformation is delayed and the displacement is reduced by 38. 5%. The plate member is effective in improving the stress state of the whole structure and preventing the development of the crack,which greatly improves the resistance and deformation capacity of the whole structure. The bearing capacity of the lining is 73. 9% of the force,which is still the main body of the composite structure after reinforcement. If the reinforcement is carried out with the appropriate plate member,the bearing capacity can recovered or exceed the level of the perfect lining.