基于围岩条件恶化的在役黄土隧道结构性能劣化机理与诊断加固技术研究

With the use of a large loess tunnel in our country, more complex the surrounding rock of geological environment will be and the loess unique structural and water-sensitive character lead to a variety of hazards due to deterioration of surrounding rock conditions in the process of operation, which greatly affect its function and safety. The hazards mechanism, however, is not clear and also lack of perception diagnosis evaluation standard and reinforcement technique. In order to divide different types of loess wall rock deterioration, to indicate the performance and evolution mechanism and degradation mechanisms of loess tunnel affected by the changes of internal and external environment, to establish the health diagnostic system and diagnostic criteria of loess tunnel structure of service performance and to give the structure reinforcement theory and technology of loess tunnel based on performance degradation, this project is an in-depth study on deterioration mechanism, diagnostic system, diagnostic criteria and reinforcement technology of loess tunnel affected by the deterioration of the surrounding rock conditions by field and indoor testing and theory analysis based on the existing large quantities of measured data analysis. The project not only further improves the theoretical system of loess tunnel maintenance, but also provides the necessary basic data and scientific basis for corresponding norms (or regulations) revision of China's highway tunnel, and it also has significant economic and social benefits.

随着我国大量黄土隧道的建设使用，围岩赋存的地质环境将变得更为复杂，加之黄土独特的结构性与水敏性，导致隧道在运营中因农业灌溉、降雨入渗、地下水位变化等围岩恶化条件下出现了各种病害，大大影响了其使用功能与安全性，而目前这些病害机理尚不明确，尚缺乏诊断评价标准及加固技术。本项目将结合已建的实体工程，在对现有大量实测资料深入分析的基础上，通过现场测试、室内试验和理论分析等手段对黄土隧道因受围岩条件恶化影响的结构性能劣化机理、诊断标准与加固技术等进行深入研究，旨在划分黄土隧道围岩条件恶化类型，揭示黄土隧道结构在不同围岩条件恶化类型下的性能演化机理和退化机制，建立黄土隧道结构服役性能的健康诊断体系与标准，给出因围岩条件恶化导致结构性能退化的隧道加固理论与技术。通过项目的研究不仅可进一步完善黄土隧道养护理论体系，而且将为我国公路隧道相应规范（或规程）修订提供必要的基础数据和科学依据，经济与社会效益显著。

由于黄土显著地结构性与水敏性，隧道运营过程中因农业灌溉、降雨入渗、地下水位变化等围岩浸水条件下衬砌结构性能发生劣化，本课题引入黄土结构性参数与黄土结构性本构关系，运用有限元二次开发、数值计算、物理模型试验和数理统计等手段，结合自主研制的“隧道衬砌结构力学性能测试平台”，详细研究了黄土围岩浸水恶化后隧道衬砌结构性能演化特征和劣化机理；通过将试验成果与已有的相关规范和研究成果相结合，选取合理的评价指标，采用模糊数学及短板效应等理论方法，建立了适用于围岩浸水恶化下黄土公路隧道衬砌结构健康评价体系；最后利用自主研制的“隧道衬砌裂缝诊治平台”，选出了适用于隧道衬砌结构裂缝修补的地聚合物胶凝材料的最佳配合比，并通过“隧道衬砌裂缝诊治平台”模拟了隧道衬砌裂缝的张拉应力开裂和带水状开裂，研究了地聚合物胶凝材料在两种状态下的粘结性能和修补效果，论证了地聚合物胶凝材料作为衬砌裂缝修补材料的可行性。