黄土隧道台阶法施工过程围岩压力的实测与影响因素分析

Measurement and Analysis of the Variation Characteristics of Surrounding Rock Pressure During the Construction Process of Loess Tunnel Step Method

以甘肃省内某一黄土隧道工程为研究对象,进行实测,分析了台阶法施工过程围岩压力的变化特征。采用智能压力传感器,分别连续采集隧道下台阶、仰拱、二次衬砌施工前后7 d的围岩压力数据;同时,采用数据处理软件,分析了隧道施工各工序对隧道围岩压力的影响。分析发现:隧道二次衬砌施工对隧道围岩压力影响最大,其次是下台阶施工,而仰拱施工对围岩压力的影响最小;隧道下台阶施工对隧道拱腰部位围岩压力的影响最大;隧道二次衬砌施工后,围岩压力呈先下降后升高的趋势。

Taking a loess tunnel project in Gansu Province as the research object,the variation characteristics of surrounding rock pressure during the step method construction process were analyzed through actual measurement.Using intelligent pressure sensors,continuously collect rock pressure data for 7 days before and after the construction of the lower steps,inverted arches,and secondary lining of the tunnel;At the same time,data processing software was used to analyze the impact of various construction processes on the surrounding rock pressure of the tunnel.Analysis shows that the secondary lining construction of the tunnel has the greatest impact on the surrounding rock pressure of the tunnel,followed by the lower step construction,while the inverted arch construction has the smallest impact on the surrounding rock pressure;The construction of the lower steps of the tunnel has the greatest impact on the surrounding rock pressure at the arch waist of the tunnel;After the secondary lining construction of the tunnel,the surrounding rock pressure shows a trend of first decreasing and then increasing.