通过分析近20年来国内隧道改扩建的发展历程，梳理增建隧道、原位扩建隧道、组合扩建隧道及改建隧道等不同型式的案例，归纳隧道改扩建型式、施工工法、施工力学响应、支护参数设计与优化、安全控制等研究热点的进展，并指出存在的不足。具体如下： 1）在改扩建型式研究上，不同工程的选型指标差异大，缺乏指导性标准； 2）在施工工法研究上，设计多偏于保守，如何利用既有隧道衬砌并实现高效施工，亟待系统研究； 3）在施工力学响应及支护参数的研究上，不同工程的现场监测、解析求解、数值模拟结果存在较大差异，且缺乏对复杂动态加卸载条件下围岩变形、应力及塑性区演变规律的研究，需结合更多的工程实践总结出特点及规律，并建立支护参数优化分析体系； 4）在施工安全控制研究上，主要从减轻爆破振动、优化支护布置、软弱围岩局部加固及施工辅助措施方面考虑，并制定风险源评价的定量指标体系。最后，展望隧道改扩建工程标准化设计、信息化管理、绿色施工及快速建造的发展方向。
In this study,
the development history of tunnel rehabilitation and expansion in China over
the last 20 years is investigated. Furthermore, the cases of additional
tunnels, insitu expansion tunnels, combined expansion tunnels, and
rehabilitated tunnels are summarized, and the development status of the
research magnets, including rehabilitation and expansion modes, construction
methods, construction mechanical responses, support parameters design and
optimization as well as safety control of tunnels are examined, and their
corresponding shortcomings are proposed. The specifications are as follows:
first, the evaluation indices of various projects differ in terms of
rehabilitation and expansion modes, and there is no standard guideline. Second,
the design is more conservative in terms of construction methods, and it is
critical to research how to realize efficient construction based on the
existing tunnel lining. Third, in terms of the construction mechanical
responses and support parameters, the field monitoring, calculation, and
numerical simulation results of several projects vary, and there is no study on
the development laws of surrounding rocks′ deformation,
stress, and plastic zone under complex dynamic loading condition, which shows
that more project applications should be studied, and an analysis system should
be established for support parameters optimization. Fourth, in terms of the
construction safety control, considerations should be made for blasting
vibration reduction, support layout optimization, local reinforcement of weak
surrounding rock, and construction auxiliary measures as well as the
development of a quantitative index system for evaluating risk sources.
Finally, the tunnel rehabilitation and expansion project′s development directions of standardized design, information
management, green construction, and rapid construction are prospected.
