贵阳七冲村二号浅埋偏压大跨度隧道施工力学特性研究

发布时间：2018-04-24 12:23

本文选题：浅埋偏压大跨度隧道 + 力学特性　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：近年来,我国的公路隧道从起初的双向四车道、双向六车道,发展到今天的双向八车道,隧道断面面积变得越来越大,隧道的开挖跨度也在不断增大。隧道开挖跨度增大,若保持一般隧道的扁平率,开挖的断面面积会过大,成本会大幅增加,为了确保一定的成本,我国的大跨度隧道还是保持一样的高度,造成隧道的扁平率减小,隧道围岩和支护结构的受力变得更加复杂,提高了隧道的施工风险和隧道安全的不确定性。因为其结构受力的不确定性和自然灾害的影响,不断有大跨度公路隧道出现塌方事故和其他隧道灾害,所以必须加强对大跨度隧道开挖过程中围岩和支护结构受力的研究,了解其特性,确保隧道施工安全和后期的稳定性。本文采用数值模拟的方法对两车道、三车道、四车道三种不同跨度隧道的围岩压力特性进行分析,并结合查阅的相关资料可以得出浅埋偏压大跨度隧道开挖围岩压力的基本特征。本文还依托浅埋偏压大跨度岩溶隧道施工关键技术研究项目,以贵阳黔春大道七冲村二号隧道为工程背景,对其整个施工过程中的隧道围岩受力和支护结构受力进行实时监测,其主要包括:围岩与初衬间压力监测、钢拱架应变监测、初衬与二衬间压力监测、二衬混凝土应变监测等。通过对监测数据的分析,掌握特大跨度小矢跨比岩溶隧道三台阶法施工时隧道围岩和支护结构的受力变化规律。同时利用GTS NX有限元软件对七冲村二号隧道进行三维数值模拟,提取其结果绘制成变化规律曲线,与现场监测数据对比分析,加深对贵阳七冲村浅埋偏压大跨度隧道施工力学的了解。开展对施工动态下围岩受力和支护结构受力规律的研究,能够不断完善浅埋大跨度隧道围岩压力理论体系,对实际工程进行指导,为我国未来的大跨度隧道建设提供经验依据,对提高我国高速公路隧道的整体水平具有实际意义。本文还总结了一些常用于计算浅埋大跨度隧道开挖围岩压力的方法,并进行分析比较,得出相对适用于计算浅埋大跨度隧道围岩压力的方法,并在此基础上得出适用于浅埋偏压大跨度隧道围岩压力的计算公式。
[Abstract]:In recent years, the highway tunnel in our country has developed from four lanes and six lanes to eight lanes. The cross-section area of the tunnel has become larger and larger, and the excavation span of the tunnel is also increasing. If the tunnel excavation span is enlarged, if the flat rate of the general tunnel is maintained, the section area will be too large and the cost will increase substantially. In order to ensure a certain cost, the long-span tunnel in our country will maintain the same height. As a result, the flat rate of tunnel is reduced, and the stress of surrounding rock and supporting structure becomes more complex, which increases the construction risk and the uncertainty of tunnel safety. Because of the uncertainty of the structural force and the influence of natural disasters, there are continuous collapse accidents and other tunnel disasters in the large-span highway tunnel, so it is necessary to strengthen the study on the surrounding rock and supporting structure forces during the excavation of the long-span tunnel. Understand its characteristics to ensure tunnel construction safety and later stability. In this paper, the characteristics of surrounding rock pressure of two lanes, three lanes and three different span tunnels are analyzed by numerical simulation. The basic characteristics of surrounding rock pressure in excavation of long span tunnel with shallow-buried bias pressure can be obtained by combining the relevant data. This paper also relies on the key technology research project of shallow buried bias pressure large span karst tunnel construction, taking Qianchun Avenue Qichong Village No. 2 Tunnel in Guiyang as the engineering background, and carries on the real-time monitoring to the surrounding rock force and the support structure force of the tunnel during the whole construction process. It mainly includes: pressure monitoring between surrounding rock and initial liner, strain monitoring of steel arch frame, pressure monitoring between initial lining and second liner, strain monitoring of concrete with second liner, etc. Based on the analysis of monitoring data, the law of stress variation of surrounding rock and supporting structure of large span karst tunnel with small rise-to-span ratio is grasped. At the same time, GTS NX finite element software is used to simulate Qichongcun No. 2 Tunnel, and the results are drawn into the changing law curve, and compared with the monitoring data. To deepen the understanding of construction mechanics of long span tunnel with shallow buried bias pressure in Qichong Village, Guiyang. The research on the stress of surrounding rock and the force law of supporting structure under dynamic construction can improve the theoretical system of surrounding rock pressure of shallow long span tunnel, guide the actual project, and provide the experience basis for the construction of long span tunnel in our country in the future. It is of practical significance to improve the overall level of highway tunnel in China. This paper also summarizes some methods which are often used to calculate the surrounding rock pressure of shallow long span tunnel excavation, and makes an analysis and comparison, and obtains a method which is relatively suitable for calculating the surrounding rock pressure of shallow long span tunnel. On this basis, a formula for calculating the surrounding rock pressure of long span tunnel with shallow burying bias pressure is obtained.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

【相似文献】