黄土隧址区隧道稳定性评价及处治措施分析

Stability evaluation and treatment measures of tunnel in loess tunnel site

文章以拟建某隧道为例,就黄土隧址区隧道围岩开挖稳定性及处治措施展开论述,重点对隧道进出口段边坡稳定性、洞身段湿陷性黄土基底及其施工处治措施进行分析,并对洞口段施工工序及施工方法提出明确要求。结果表明:黄土陷穴、黄土滑塌及湿陷性黄土的处理至关重要,对隧址区黄土陷穴进行开挖回填夯实处理;黄土滑塌多为小型表层,进行清除并采取适宜的坡率及防护措施;对湿陷性黄土地基采取高压旋喷桩进行基底加固处理,消除湿陷性,提高地基承载力。

Taking a tunnel to be built as an example,this paper discusses the stability of surrounding rock excavation and treatment measures of tunnel in loess tunnel site area,focuses on the analysis of slope stability of tunnel inlet and outlet section,collapsible loess basement of tunnel body and its construction treatment measures,and puts forward clear requirements for the construction procedure and construction method of tunnel entrance section.The results show that the treatment of loess sag,loess slump and collapsible loess is very important,and the excavation and backfilling and tamping treatment of loess sag in the tunnel site are carried out.The loess slippage is mostly small surface layer,which should be cleared and appropriate slope rate and protection measures should be taken.In order to eliminate the collapsibility and improve the bearing capacity of the foundation,high pressure rotary jet grouting pile is adopted to strengthen the foundation of collapsible loess foundation.