研究目的：随着城市轨道交通的发展，会出现越来越多的新线近接既有线路的结构施工。为保护环境，许多构思仔细的工法得到了广泛的应用。本文将针对具体工程分析明挖新线对既有车站结构的影响。
研究方法：鉴于问题的复杂性，采用三维增量有限元弹性分析的方法，全程模拟了在既有结构存在的条件下，新线三个不同区域的不同施工方法，对既有线结构的变形进行了分析，并对新线的施工方法进行了优化。
研究结果：新线分三段区域(中间及两侧)施工，其中中间区域分块开挖。在中间区域施工过程中，既有结构的隆起控制在2.67mm以下。在整个新线施工过程中，既有结构最大隆起不是在施工完成后，而是出现在靠近中间区域先挖一侧基坑开挖完成后，为7.82 mm；改变两侧区域的施工顺序后，既有线结构的最终隆起量基本不变，但过程最大隆起量减为7.43 mm。
研究结论：近距离上穿既有结构施工时，采用合适的工法可以有效地控制既有结构的隆起。在施工中，既有结构的隆起可能出现在施工过程的某一阶段。合理的施工顺序有助于控制施工过程中既有结构的最大隆起量。
Research purposes: With the development of urban railway traffic, more and more new lines will be constructed near existing ones. To protect the environment, many construction methods are widely applied. This paper analyzes the displacements of existing station's structure caused by the construction of new line.
Research methods: Different construction methods will be applied in three different areas during building of new line. The problem is rather complicated; therefore the incremental finite element elastic analysis method will be used to simulate the whole construction process. The construction method of new line will be optimized based on the computed data.
Research results: According to the relative position to existing structure, the whole area of new line is divided into three parts, namely the middle part and two sides. The middle part is excavated incrementally and braced in time, which results in the heave no more than 2.67 mm. The crest of heave which is 7.82 mm occurred during rather than after the construction. When the construction sequence of the two sides is changed, the maximum heave of existing line structure during the construction reduces to 7.43 mm while the final heave value is almost unchanged.
Research Conclusions: Reasonable construction method can efficiently control the heave of existing building regardless of its short distance to the new line. The maximum heave may occur during the construction period. Reasonable construction sequence can contribute to control the heave value of existing building.
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