中文摘要：

为研究黄土公路隧道洞口段的变形规律,以陕西境内吴子高速公路刘家坪2号隧道右线为依托,采用现场监控量测的方法,对洞口段的净空收敛、围岩内部位移及拱部下沉进行测试。结果表明:(1)从同一时刻2个断面拱部下沉和净空收敛的数据来看,拱部下沉明显大于净空收敛,因此施工中应以控制拱部下沉为主;(2)变形数据的规律反映洞口段的地形偏压情况;(3)洞口段拱部下沉时态曲线为基本稳定型,主要标志为下沉时态曲线平缓上升,但变形速率逐渐下降,表明该段黄土地层趋于稳定状态;(4)2个断面的6条拱部下沉时态曲线的规律基本相同,表明虽然经历边墙和仰拱施工等巨大的空间变化,但下沉时态曲线无明显突变,表明马兰组新黄土地层的位移规律,其时间效应比空间效应显著。研究结果可为洞口段的设计与施工提供理论依据,为类似隧道工程洞口段的建设提供借鉴。

英文摘要：

In order to study the deformation law of entrance section for loess highway tunnel,based on the right line of Liujiaping No.2 tunnel of highway from Wubu to Zizhou in Shaanxi Province,in-situ tests were conducted. The tunnel construction deformation was measured,and the regression analysis was made in data processing of in-situ test. The results show that:(1) From the arch subsidence and clearance convergence data of the same time in two sections,it is found that the arch subsidence is greater than clearance convergence,so the arch subsidence should be mainly controlled during the construction:(2) The deformation data reflect the bias voltage of the portal section. (3) Tense curve of the arch subsidence is basically stable,the main indicator is the tense curve of subsidence gently rising,but the deformation rate decreases gradually which shows that the loess strata become stable;(4) The tense curves of 6 arch subsidence in two section are basically the same,it shows that although the sidewalls and inverted arch experience a tremendous spatial variation during the construction,there is no obvious mutation in the tense curve of the subsidence. The displacement law of the Malan new set loess stratigraphy was shown,and the time effect was more significant than spatial effect. The study results can provide a theoretical basis for the design and construction of the portal section,and a reference for similar tunnel project portal section construction.