隧道洞口段的加固方案设计及稳定性研究

Reinforcement scheme design and stability study of tunnel entrance section

为了保证砂土地层洞口段的进洞安全,以拉林铁路米林隧道为工程实例背景,在充分研究地质条件的基础上,对其洞口段的加固方案进行设计,并结合施工过程,进一步开展施工质量评述;以隧道变形监测成果为基础,开展隧道变形的尖点突变分析,以评价隧道围岩的稳定性。结果表明:水平旋喷桩可有效改良洞口段的围岩性质,对处理自稳能力差的围岩具有较好的适用性,且在应用过程中,应加强现场监督,对遇到的工程问题进行实时调整;通过尖点突变分析,得出加固后的洞口段围岩均处于稳定性状态,验证加固方案的有效性。

In order to ensure the safety of entrance of tunnel in sandy soil stratum,this paper took Millin tunnel as an example,designed the reinforcement scheme of tunnel entrance on the basis of fully studying geological conditions,and further carried out the construction quality evaluation combined with the construction process.Based on the monitoring results of tunnel deformation,the analysis of sharp point mutation of tunnel deformation was carried out to evaluate the stability of tunnel surrounding rock.The cusp catastrophe analysis of tunnel deformation was developed to evaluate the stability of tunnel surrounding rock.The case study shows that the horizontal jet grouting pile can effectively improve the surrounding rock properties of the entrance section,and has good applicability to deal with the surrounding rock with poor self-stabilization ability.In the application process,the site supervision should be strengthened,and the engineering problems encountered should be adjusted in real time.Through cusp catastrophe analysis,the surrounding of the entrance section after reinforcement can be obtained.The rock is in a stable state,which verifies the effectiveness of the reinforcement scheme.