预切槽法开挖黄土隧道地层变形规律及掌子面稳定性研究

发布时间：2018-05-24 09:47

本文选题：黄土隧道 + 机械预切槽法　；参考：《北京交通大学》2014年硕士论文

【摘要】：随着我国隧道建设的快速发展,复杂地质和劳动力紧缺等问题越来越多。能适用复杂地质和环境的机械化开挖方式,将会是隧道建设的发展趋势。机械预切槽法作为一种独特的施工技术,可适合复杂的地质和环境,同时可大大提高施工的机械化水平。其在法国、意大利、日本等国家得到了较为广泛的应用,随着我国隧道建设面临的复杂地质和环境问题的增多以及对机械化的迫切需要,这种技术将再次引起关注,因此对预切槽技术的研究是很有必要的。本文依托现场试验段并通过数值模拟手段,对预切槽法开挖黄土隧道进行了研究,主要工作内容和成果包括： (1)从覆土厚度、地层参数等方面研究了预切槽法开挖黄土隧道的地层变形规律,同时与传统黄土隧道开挖方法做了对比分析。 (2)预切槽法合理支护参数研究。对预衬砌的长度、搭接长度及厚度做了对比分析,并针对试验段工况,确定了合理的支护参数。 (3)对比了采用两种不同的预衬砌长度(5m、12m)时的洞周变形和预衬砌应力,并对12m长预衬砌的情况从掌子面前方土体预加固和辅助措施两方面做了进一步分析。 (4)预切槽法施工下的掌子面稳定性问题研究。介绍了掌子面稳定性的影响因素和破坏机理,同时引用了边坡稳定的方法分析掌子面的稳定性。 (5)实例分析。通过隧道洞周变形和预衬砌应力两方面的对比分析,确定了现场试验段的开挖方式和仰拱封闭距离。
[Abstract]:With the rapid development of tunnel construction in China, there are more and more problems such as complex geology and labor shortage. Mechanized excavation mode which can be applied to complex geology and environment will be the development trend of tunnel construction. As a unique construction technology, mechanical pre-cutting method can adapt to complicated geology and environment, and greatly improve the mechanization level of construction. It has been widely used in France, Italy, Japan and other countries. With the increase of complex geological and environmental problems in tunnel construction in China and the urgent need for mechanization, this technology will once again attract attention. Therefore, it is necessary to study the technology of pre-cutting slot. Based on the field test section and numerical simulation method, this paper studies the excavation of loess tunnel by pre-cutting method. The main work and results are as follows: 1) the formation deformation of loess tunnel excavated by precut groove method is studied from the aspects of overlying soil thickness and stratum parameters, and is compared with that of traditional loess tunnel excavation method. 2) study on reasonable support parameters of pre-cutting groove method. The length, lap length and thickness of the pre-lining are compared and analyzed, and the reasonable supporting parameters are determined according to the working conditions of the test section. The deformation around the hole and the stress of the pre-lining are compared when two different pre-lining lengths are adopted. The condition of the pre-lining with 12m long is further analyzed from the aspects of soil pre-reinforcement and auxiliary measures in front of the face. 4) study on the stability of the face of the palm under the construction of the pre-cutting groove method. This paper introduces the influencing factors and failure mechanism of palm face stability, and analyses the stability of palm face by using slope stability method. Case study. Through the comparative analysis of tunnel circumference deformation and pre-lining stress, the excavation mode and the closed distance of inverted arch are determined.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U452.11

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