【作者】 仇文革；

【导师】 关宝树；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2003， 博士

【摘要】 近年来，随着基础设施，尤其是交通设施(铁路、公路等)建设的发展，大量地出现了在既有线(如铁路或公路等)旁修建新线(如复线铁路、高速铁路、高等级或高速公路等)等工程现象，且规模越来越大，距离越来越近。这势必造成新建结构物与既有结构物邻近和错综复杂的关系，从而产生对既有结构物的种种不利影响。随着建设规模的加大，导致这种事例越来越多。如新建隧道(或广义的地下工程)邻近既有隧道施工，两个及以上相邻隧道同期施工，甚至于大断面洞室的分部开挖、工法优化问题等。同时，城市地下铁道等地下工程的大量修建也越来越多地遇到了这类问题，即地下工程近接施工问题。 在地下工程近接施工中，新建结构物的施工会改变既有结构物的受力状态，从而对其产生种种不利影响，如结构承载力下降、甚至破坏，变形过大侵入限界等。同时新建结构物的受力模式也不同于半无限体或无限体中修建单一洞室的一般状况，其初始应力场往往是经过多次扰动的，其施工将再次进行扰动，使其受力往往是非对称的，表现出极大的变异性。概括地讲，新建结构物的施工会使围岩从原来的三次应力场演变到五次应力场，正是这种应力的演变导致了既有结构和新建结构的受力变异，造成既有侧的安全性和新建侧的复杂性问题。它是摆在我们面前的不可回避和必须加以解决的问题。然而，由于新建工程规模大小、新旧之间的位置关系、地质条件、既有结构物健全度和新建工程施工方法等不同导致其影响程度也不同，其间零零种种的受力机理是极其复杂的。因此，研究其复杂的受力机理和相应对策已成为当务之急。为此，各国有识之士对此给予了高度重视并开展了大量研究。 国外，在进行大规模建设时对这类问题研究较多，起步较早，有的成果已形成设计、施工指南。如日本对接近既有铁路隧道的各类近接施工问题做了较全面的研究和系统的总结，并形成了指南。但其多基于经验，且对更广泛范围的近接施工问题尚未做出系统的总结。 国内，近年来随着这类事例的增多，也开展了许多这方面的研究，并取得了一些成功的经验。但多为就事论事，缺乏系统的理论分析，设计与施工尚未形成规范。导致不是采取过于保守的对策，造成很严重的浪费，就是采取过于冒险或盲目的对策，造成安全的问题。 本文结合作者多年来对华蓥山隧道减少压煤量研究、深圳地铁重叠隧道第11页 西南交通大学博士研究主学位论文技术研究、广州地铁公纪区间广纺联段邻桩施工对策研究和重庆轻轨大坪大断面车站邻近基础浅埋暗挖工法优化分析等诸多近接施工问题案例的研究，在系统分析和归纳总结国内外相关研究成果的基础上，系统地提出了广义的地下工程近接施工的分类、分区、分区指标表达式、近接度与对策等级概念以及分区、分度准则，给出了研究和解决近接施工问题的普遍方法，如数值分析先行，模型试验、现场测试验证等。同时，针对典型案例研究，建立了近接施工影响预测的力学模型，如随动弹性地基梁、横向效应、纵向效应等，提出了厂挖影响线等概念和纵向分段梁、横向非等参支护等对策。本文中几种典型案例对策研究的结果均被设计、施工采纳，并在课题鉴定、评审中获得了国内领先、国际先进水平的评价。 随着我国大规模基本建设的展开，近接施工的案例将会越来越多且越来越复杂，其研究可谓方兴未艾。作者旨在抛砖引玉，本着继承与发展的法则，深入厂展此类问题的研究，分清矛盾的普遍性和特殊性，将有助十地下空问资源的充分利用和地下工程的可持续发展。更多还原

【Abstract】 In recent years, with the development of the basic establishment, especially means of transportation (railway, highway, etc.), the engineering phenomena that new line (such as double-track railway, high speed railway, expressway, etc.) is built close to existing line (such as railway, highway, etc.) appears. The size is larger and lager, and the space between is closer and closer. That must be done the new structure is close to the existing structure, with complex mechanics behaviors and some bad influence to the existing structure. With the increase of construction size, these examples are increasing, such as newly-built tunnel close to the existing tunnel, two or more closely spaced tunnels built at the same time, large cross section cavern excavated partly and construction methods optimized. At the same time, this problem is faced more and more in plentiful construction of urban underground works liked Metro. This kind of problem is called approaching excavation of underground works.In course of the approaching excavation of underground works, the construction of new structure will change the mechanics case of existing structure and brings some bad influence, such as load bearing capacity of structure decreasing, structure breaking, or too much deformation of structure and construction gauge inroaded. At the same time, the mechanics mode of newly-built structure is not the same as that single cavern is excavated in the half-unbounded space. Its original stress field is disturbed by former time and time again, and once more by excavating of later. So the mechanics mode of the later is not symmetrical generally and infinite variability is put up. Resumptively, the construction of new structure will change the third stress field to the fifth stress field in surrounding rock, and bring the safety problem of existing structure and the complexity problem of newly-built structure. It is a ineluctable problem that we must face and treat. However, the mechanics mechanism is very complicatedbecause of the difference of the size of newly-built structure, position between newly-built structure and existing structure, stratum condition, healthiness degree of existing structure, construction methods of new structure, etc. So the urgent affairs is study of the complexity mechanics mechanism and corresponding countermeasure. Therefor, everyone of insight all over the world pays great attention to and study it.Overseas, the problem is studied relatively excessive and early. Some productions have been the guide of design and construction. In Japan, the problem of approaching excavation that newly-built structure is close to existing railway tunnel is studied and summarized by the numbers, and the guide was published. But it bases on experience and is not summarized to comprehensive problem of approaching excavation.Interiorly, with the increase of these examples in recent years, some study is developed and some successful experience is obtained. But most study is considered as it stands, systemic theory analysis is scare and specification has not been established in design and construction. The result is that conservative countermeasure which brings serious waste is adopted or hazardous and eyeless countermeasure which brings safety problem is adopted.A good many case of approaching excavation are studied in this article, such as the study of infection of be coal mining to the Huayingshan tunnel, technology study of strucked tunnels of Metro in Shenzhen, countermeasure study of tunnel approaching pile foundation of Metro in Guangzhou, excavation methods optimized of large cross section subaqueous tunnel approaching pile foundation of LRT in Chongqing, etc. On the basic of analysing and concluding relative study production all over the the world by the numbers, classification of approaching excavation, partition of approach zone, formula of partition of approaching zone, approach degree and countermeasure grade of generalized approaching excavation of underground works are put forward. General methods studying更多还原