复杂条件下青藏铁路路基冷却措施的适应性研究

To reveal the adaptability of cooling subgrade measures (ventilated subgrade, heat-pipe subgrade and crushed-rock subgrade) for Qinghai-Tibet Railway in permafrost region of Qinghai-Tibet Plateau under different conditions (climate warming rate, temperature zoning and permafrost conditions), and to ensure the long-term stability of subgrade engineering in permafrost region. This project intends to study thermodynamic state of permafrost under the cooling subgrade by location monitoring and physical simulation. Large dataset of cooling subgrade for Qinghai-Tibet Railway is established. An evaluation system of service performance for permafrost subgrade engineering is put forward. Then, the long-term cooling effect and deformation behavior of cooling subgrade engineering under different conditions are analyzed, and the development process of service performance for cooling subgrades under different conditions is evaluated. This project intends to clarify the response mechanism between the main deformation sources and the engineering stability, and reveals the applicability of the cooling subgrade measures under different conditions, and puts forward the countermeasures to improve the long-term stability and service performance for the Qinghai-Tibet Railway subgrade engineering. The above research will provide scientific basis and technical guarantee for the safe operation of Qinghai-Tibet Railway engineering and the design or construction of similar engineering.

为揭示青藏高原多年冻土区青藏铁路路基冷却措施（通风管，热管和块石类路基）在不同条件下（气候变暖速率、气温分区和冻土条件）的适应性，确保多年冻土区路基工程的长期稳定性。本项目拟通过对青藏铁路冷却路基工程下冻土热力状态的定位监测和数值模拟研究，建立青藏铁路冷却路基大数据集，提出冻土路基工程服役性能评价体系，分析不同条件下青藏铁路冷却路基的长期降温效果和变形行为，研究不同条件下冷却路基工程服役性能的发展过程。阐明冷却路基工程主要变形源与工程稳定性间的响应机制，揭示不同条件下冷却路基措施对青藏铁路工程的适用性，提出改善路基工程长期稳定性和服役性能的对策，为青藏铁路工程的安全运营和同类工程的设计与建设提供科学依据和技术保障。

为揭示青藏高原多年冻土区青藏铁路典型冷却路基措施在不同条件下的适应性，确保多年冻土区路基工程的长期稳定性。本项目通过定位监测和数值模拟，研究了不同条件下青藏铁路典型冷却路基的长期降温效果和变形行为，总结了冷却路基工程主要变形源变化的一般规律，阐明了冷却路基工程主要变形源与工程稳定性间的响应机制，揭示了不同条件下典型冷却路基的适应性。建立了基于地温和变形的青藏铁路冷却路基工程服役性能评价体系，分析并预测了典型冷却路基工程服役性能的变化规律和服役年限，提出了改善典型冷却路基工程长期稳定性和服役性能的对策。研究成果对青藏铁路工程的安全运营和同类工程的设计与建设具有重要的理论参考价值和现实指导意义。