The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and lo...The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and low ductility was introduced.And it was made as filling material of reserved deformation layer between the first lining and the second lining used in large-span soft rock tunnel.The effect of the new type of foam concrete was simulated as filling material of reserved deformation layer using numerical simulation.Through the comparison with the common large-span soft rock tunnel,the vault settlement and surrounding convergence are reduced by about 61% and 45%,respectively,after creep of 100 a.And in the second lining,the plastic zone reduces apparently and the maximum equivalent plastic strain decreases relatively.So,it can be found that the application of the new type of foam concrete as the filling material of reserved deformation layer can relieve the excessive force in second lining induced by rock creep,reduce its deformation and improve the stability of tunnel.展开更多
为探究冲击荷载和爆炸荷载作用下隧道变形行为特征,提出了一种模型试验与数值模拟相结合的方法来分析不同动态荷载条件下隧道的损伤行为和模式。以海螺沟隧道为研究对象,采用模型试验和数值模拟相结合的方式,首先对缩尺物理隧道模型进...为探究冲击荷载和爆炸荷载作用下隧道变形行为特征,提出了一种模型试验与数值模拟相结合的方法来分析不同动态荷载条件下隧道的损伤行为和模式。以海螺沟隧道为研究对象,采用模型试验和数值模拟相结合的方式,首先对缩尺物理隧道模型进行冲击测试,接着对隧道模型进行数值分析并完成验证,然后对比了小比例隧道模型和原型模型在冲击荷载下的隧道变形结果,最后分析了爆破荷载对原型隧道变形的影响。研究结果表明:本研究提出方法能够真实反映实际冲击荷载对隧道变形的影响;缩尺隧道模型的数值分析结果与试验结果较为吻合;在冲击荷载作用下,原型隧道顶部的约为缩尺物理模型的10倍;原型隧道数值模型在冲击荷载作用下顶部变形量与500 kg TNT爆破荷载造成的变形较为一致,利用冲击荷载可有效模拟爆破载荷对隧道拱顶的损伤情况;增大覆盖深度和减小冲击荷载是避免隧道造成重大损伤的有效举措。本研究的成果克服了地表爆破时现场测试的困难,为分析隧道在不同动态荷载作用下的破坏行为和模式提供一种低成本、安全可靠的测试方法,为优化爆破荷载的隧道安全、经济的设计提供技术支撑。展开更多
基金Projects(41072238,51009133)supported by the National Natural Science Foundation of China
文摘The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and low ductility was introduced.And it was made as filling material of reserved deformation layer between the first lining and the second lining used in large-span soft rock tunnel.The effect of the new type of foam concrete was simulated as filling material of reserved deformation layer using numerical simulation.Through the comparison with the common large-span soft rock tunnel,the vault settlement and surrounding convergence are reduced by about 61% and 45%,respectively,after creep of 100 a.And in the second lining,the plastic zone reduces apparently and the maximum equivalent plastic strain decreases relatively.So,it can be found that the application of the new type of foam concrete as the filling material of reserved deformation layer can relieve the excessive force in second lining induced by rock creep,reduce its deformation and improve the stability of tunnel.
文摘为探究冲击荷载和爆炸荷载作用下隧道变形行为特征,提出了一种模型试验与数值模拟相结合的方法来分析不同动态荷载条件下隧道的损伤行为和模式。以海螺沟隧道为研究对象,采用模型试验和数值模拟相结合的方式,首先对缩尺物理隧道模型进行冲击测试,接着对隧道模型进行数值分析并完成验证,然后对比了小比例隧道模型和原型模型在冲击荷载下的隧道变形结果,最后分析了爆破荷载对原型隧道变形的影响。研究结果表明:本研究提出方法能够真实反映实际冲击荷载对隧道变形的影响;缩尺隧道模型的数值分析结果与试验结果较为吻合;在冲击荷载作用下,原型隧道顶部的约为缩尺物理模型的10倍;原型隧道数值模型在冲击荷载作用下顶部变形量与500 kg TNT爆破荷载造成的变形较为一致,利用冲击荷载可有效模拟爆破载荷对隧道拱顶的损伤情况;增大覆盖深度和减小冲击荷载是避免隧道造成重大损伤的有效举措。本研究的成果克服了地表爆破时现场测试的困难,为分析隧道在不同动态荷载作用下的破坏行为和模式提供一种低成本、安全可靠的测试方法,为优化爆破荷载的隧道安全、经济的设计提供技术支撑。
