外部水源作用下冻土路基水热耦合动力学机制与程序实现

A lot of roadbed disease in Permafrost Regions has become the most pressing highway maintenance problems, which are caused by the widely distributed hydrops along the subgrade and the groundwater..This project is based on Qinghai-Tibet Highway and services in the construction of Qinghai-Tibet highway in the future, according to the characteristics of external water in Permafrost Regions of Qinghai Tibet Plateau engineering, we plan to develop the research on the water heat coupling model problem of frozen soil under the action of external water from three aspects: establishing the permafrost roadbed water heat coupling model based on open system and calculation program, calculating quantitatively the parameters and boundary conditions of frozen soil water heat coupling link, water heat distribution inside the road under the influence of external water and the forecasting model of key parameter, etc..The main research contents include the investigation and analysis of hydrops along the subgrade and groundwater of Qinghai-Tibet highway, the drilling test observation of typical sections and hot melt pond along the subgrade, the diffusion test of typical soil, the model test of water heat coupling and one-dimensional freezing experiment of frozen soil subgrade, setting up water heat coupling model under the action of external water which is influenced by many factors, and corresponding calculation program for numerical simulation, etc. The research results have important academic value and engineering significance for revealing the infiltration mechanism of hydrops along the subgrade and groundwater, and disaster prevention and mitigation in permafrost regions.

路侧积水的广泛分布与地下水径流的存在导致大量路基病害发生已成为多年冻土区公路养护亟待解决的问题。本项目将以青藏公路为依托，着眼于未来青藏高速公路的建设，针对青藏高原工程走廊带多年冻土区外部水源强度大的特点，拟从基于开放系统的冻土路基水热耦合模型的建立与程序实现、冻土水热耦合纽带参数与边界条件量化计算、外部水源影响下路内水热分布规律与关键参数预测模型等3个方面对对外部水源强度作用下的冻土水热耦合问题开展研究。主要研究内容包括青藏公路路侧积水与地下水调查分析，典型断面与路侧热融湖塘钻探测试观测，典型土渗透扩散特性测试，冻土路基水热耦合模型实验和一维冻结实验，建立考虑多因素影响的外部水源作用下水热耦合模型并编制相应计算程序进行数值模拟等。项目研究成果对于揭示多年冻土区公路路侧积水、地下水入渗路内机理与防灾减灾，具有重要的学术价值和工程意义。

路侧积水的广泛分布与地下水径流的存在导致大量路基病害发生已成为多年冻土区公路养护亟待解决的问题。本项目将以青藏公路为依托，着眼于未来青藏高速公路的建设，针对青藏高原工程走廊带多年冻土区外部水源强度大的特点，从基于开放系统的冻土路基水热耦合模型的建立与程序实现、冻土水热耦合纽带参数与边界条件量化计算、外部水源影响下路内水热分布规律与关键参数预测模型等3个方面对对外部水源强度作用下的冻土水热耦合问题开展研究。.通过青藏高原工程走廊带地表积水与地下水调查分析，得到了走廊带冻土路基外部水源强度基本规律。建立了走廊带（西大滩-唐古拉山北麓）沿线共计1800多不同深度的土样库，以此开展大规模土样冻结融化、热物性参数测试，得到了走廊带土样过冷温度、起始冻结温度和消融温度等基本冻结融化特性，掌握了各类典型土样的导热系数、热扩散率分布基本规律并建立了相应预测方法。通过地表地下水样水化学分析和土样易融盐含量分析，得到了走廊带水、土含盐量基本规律。基于上述大量实验测试，获取了走廊带内冻土路基水热耦合动力学基本参数。建立考虑多因素影响的外部水源作用下水热耦合模型并编制相应计算程序进行数值模拟等，结合典型断面与路侧热融湖塘钻探测试观测，厘清了外部水源作用下冻土路基水热耦合动力学机制。.项目研究成果对于揭示多年冻土区公路路侧积水、地下水入渗路内机理与防灾减灾，具有重要的学术价值和工程意义。