软岩地下工程预应力锚索支护设计与施工技术研究

发布时间：2018-03-22 10:06

本文选题：软岩　切入点：隧道　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：地下工程软弱围岩支护是土木工程领域面临的技术难题。论文引入围岩松动圈理论,采用预加固技术,利用新型预应力锚索(自适应预应力锚索)作为地下工程软弱围岩开挖初期支护手段,研究了软岩地下工程预应力锚索设计参数、结构形式、施工工艺等问题。主要研究内容如下:①地下工程软弱围岩开挖应力变化特性以及围岩变形位移与围岩支护抗力之间的关系。地下工程软岩围岩开挖后原岩应力平衡遭到破坏,围岩应力调整,论文结合软岩特性、地下工程断面尺寸、预应力锚索主动支护原理等,对软岩应力变化特性、围岩变形发展、主动锚固力与塑性位移之间的关系进行研究分析。②软岩地下工程预应力锚索结构的选择及支护设计参数的确定。选用了一种新型预应力锚索(自适应预应力锚索)作为软岩地下工程初期支护结构,可在软弱围岩开挖后适应围岩的变形与应力重分布。自适应预应力锚索可根据围岩支护抗力与位移,自动调节锚索的拉力和变形量,以适应围岩大变形,还可以避免预应力锚索因变形过大导致过载或破坏,达到加固软岩地下工程大变形的目的。地下工程预应力锚索支护设计参数包括锚索锚固力、长度、间距与布置、倾角及锚固剂等。不同锚索结构形式的锚固机理各不相同,具体分析了使用自适应预应力锚索支护大变形地下工程软弱围岩的锚固参数。③软岩地下工程预应力锚索的施工技术研究。自适应预应力锚索适合于大变形软弱围岩支护。自适应锚索工程施工主要包括测量放样、钻孔、锚索制作及安装、注浆、张拉及锁定、封锚等工序,其施工工艺与传统拉力型锚索基本相同,但局部施工有所差异。④以泛亚铁路西线大理至瑞丽铁路秀岭隧道为例,初步分析软弱围岩大变形隧道采用自适应预应力锚索进行初期支护的技术方案。
[Abstract]:The soft surrounding rock support of underground engineering is a technical problem in the field of civil engineering. In this paper, a new type of prestressed anchor cable (adaptive prestressed anchor cable) is used as the initial supporting method of soft surrounding rock in underground engineering, and the design parameters and structure form of prestressed anchor cable in soft rock underground engineering are studied. The main research contents are as follows: the stress variation characteristics of soft surrounding rock excavation and the relationship between the deformation displacement of surrounding rock and the support resistance of surrounding rock. The stress balance of original rock is destroyed after excavation of soft rock surrounding rock in underground engineering. The stress adjustment of surrounding rock, combined with the characteristics of soft rock, the size of section of underground engineering, the principle of active support of prestressed anchor cable, etc., the change of stress of soft rock and the development of deformation of surrounding rock, etc. The relationship between active anchoring force and plastic displacement is studied and analyzed. .2 selection of prestressed anchor cable structure and determination of supporting design parameters in soft rock underground engineering. A new type of prestressed anchor cable (adaptive prestressed anchor cable) is selected. As the initial support structure of soft rock underground engineering, It can adapt to the deformation and stress redistribution of the surrounding rock after the excavation of the weak surrounding rock. According to the support resistance and displacement of the surrounding rock, the self-adaptive prestressed anchor cable can automatically adjust the tensile force and deformation of the anchor cable to adapt to the large deformation of the surrounding rock. It can also avoid overloading or destruction of prestressed anchor cable due to excessive deformation, and achieve the purpose of strengthening soft rock underground engineering with large deformation. The design parameters of prestressed anchor cable support in underground engineering include anchor force, length, spacing and arrangement of anchor cable. The anchoring mechanism of different cable structures is different. This paper concretely analyzes the construction technology of prestressed anchor cable used to support large deformation underground engineering soft surrounding rock with adaptive prestressed anchor cable. 3. 3. The construction technology of prestressed anchor cable in soft rock underground engineering is analyzed. The adaptive prestressed anchor cable is suitable for large deformation soft circumference. Rock support. The construction of adaptive anchor cable engineering mainly includes surveying and lofting, Drilling, cable making and installation, grouting, tensioning and locking, sealing anchor and so on, the construction technology is basically the same as that of the traditional tension anchor cable, but the partial construction is different. 4. Take the Xiuling Tunnel of the west line of the Trans-Asian Railway from Dali to Ruili Railway as an example. The technical scheme of initial support with adaptive prestressed anchor cable in large deformation tunnel of soft surrounding rock is analyzed preliminarily.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.7

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