冻土区公路路基病害断链防治技术的理论研究与实践

发布时间：2018-05-08 23:41

本文选题：冻土 + 路基病害　；参考：《重庆大学》2015年博士论文

【摘要】：冻融作用是在多年冻土地区修筑工程构筑物所面临的重大挑战之一。青藏高原冻土区公路的冻胀、沉降、路面破裂、边坡失稳等一系列病害,因为冻融作用的影响而较之正常地区更为严重。冻土区公路路基病害具有链式规律,病害链中传递的能量包括机械能(车辆荷载),辐射能(主要是外因中的太阳光辐射)和热能(气候变化导致的热量聚集)。水、辐射能和热能是导致冻土区公路路基病害的主要链源,掌握链源的传递规律,隔断和消弱辐射能(光能)和热能的传递,可以有效的防治冻土区公路路基病害。为此,本文在国家自然科学基金项目“基于灾变链式理论的多种灾害演化规律探索”(项目批准号:50879097)和教育部长江学者和创新团队发展计划项目“山区岩土工程”(项目批准号:IRT1045)的资助下,基于理论分析、数值模拟和现场试验,对冻土区公路路基病害链链源特征及断链防治原理等问题进行了全面深入的研究,论文的主要研究工作如下:①在调查分析冻土区路基病害类型及原因的基础上,运用链式理论提出了“公路病害链”概念和“断链防治”原理,并对青藏公路和青康公路等冻土区公路的路基病害链链源的“链式效应特征”及断链防治的机制进行研究。②病害链中传递的水和热能是导致冻土区公路路基病害的主要链源,通过路面、地基、边坡等外环境进入路基病害链。利用BP神经网络及ARMA模型建立了重要的外环境之一—沥青路面温度预测模型,结果表明BP模型对日最高温度的预测精度较低,对其它区间的预测误差在5%左右。研究成果丰富了沥青路面温度的预测方法,为工程需要假定路基温度场在一较短时长内的温度条件提供了参考依据。③运用热传导理论,推导了对初始及边值条件适应性强的单层及多层平板导热微分方程求解的差分格式。结合积分变换法、分离变量法以及待定系数法推导了单层半无限平板以及单层及双层平板的解析解,并运用差分计算分析了隔断类断链防治技术—XPS板隔热层的作用机理及效果。现场实测数据分析进一步验证XPS板隔热层的作用机理和多层平板导热微分方程差分法的适用性。④考虑“通风管内风速”这一要素,构建流畅与温度场耦合的通风管路基理论模型,通过数值模拟详细分析了消弱类断链防治技术的作用机理及效果。通过研究通风管路基试验段温度场的实测数据分析了路基温度场的变化规律,进一步验证了考虑管内风速影响的通风管的作用机理。⑤对于另一外环境——边坡,考虑水-冰相变后含水率对其物理、力学性能的影响,比较了Janbu法、瑞典条分法、简化Bishop法和数值分析中强度折减法,确定了冻土区高含水(冰)量粘土边坡稳定性分析的Janbu法并结合温度场计算,分析了不同含水率及7级地震工况下的边坡潜在滑裂面及安全系数。得到了可以用于冻土区高含水(冰)量粘土边坡稳定性分析的一个简便的方法。
[Abstract]:Freezing thawing is one of the major challenges in the construction of engineering structures in permafrost regions. A series of diseases such as frost heave, settlement, pavement rupture and slope instability in the permafrost region of the Qinghai Tibet Plateau are more serious because of the effect of freezing and thawing. The road subgrade disease in the permafrost region has a chain rule, and the disease chain is transmitted. The energy of delivery includes mechanical energy (vehicle load), radiation energy (mainly the solar radiation in the external cause) and heat energy (the heat accumulation caused by climate change). Water, radiant energy and heat energy are the main chain sources of highway subgrade disease in the frozen soil area. It can master the transmission law of the chain source, partition and weaken the radiant energy (light energy) and heat energy transfer, and can be effective. To prevent and control the disease of Highway Subgrade in frozen soil area, this paper is based on the National Natural Science Foundation Project "a variety of disaster evolution laws based on the catastrophic chain theory" (project approval number: 50879097) and the support of the "mountain geotechnical process" (project approval number: IRT1045) of the Yangtze River scholar and innovation team development plan project of the Ministry of Education (project approval number: IRT1045). Theoretical analysis, numerical simulation and field test have been carried out to study the characteristics of the chain chain source of highway subgrade disease and the prevention and control principle of the broken chain. The main research work of this paper is as follows: 1. On the basis of the investigation and analysis of the types and causes of the subgrade disease in the frozen soil area, the chain theory is used to put forward the "highway disease chain". The "chain effect characteristics" and the mechanism of chain fracture prevention and control are studied on the road subgrade chain source of the Qinghai Tibet highway and Qingkang highway. 2. The water and heat energy transmitted in the disease chain are the main source of the road subgrade disease in the frozen soil area, and the external environment through the pavement, the foundation, the slope and the same environment are entered. The BP neural network and ARMA model have been used to establish an important external environment, one of the important external environment, the prediction model of asphalt pavement temperature. The results show that the prediction accuracy of the BP model to the daily maximum temperature is low, and the prediction error is about 5%. The research results enrich the prediction method of the asphalt pavement temperature, which is supposed to be assumed for the project. The temperature field of subgrade provides a reference for the temperature conditions in a relatively short time. (3) using the theory of heat conduction, the difference schemes for solving the heat conduction differential equations of single layer and multi layer plate with strong adaptability to the initial and boundary conditions are derived. The analytical solution of single layer and double deck plate is analyzed, and the effect mechanism and effect of XPS plate insulation layer are analyzed by difference calculation. The field measured data analysis is used to further verify the action mechanism of the insulation layer of XPS plate and the applicability of the differential equation difference method of the multi-layer plate heat conduction differential equation. 4. One factor is to build a theoretical model of Ventilation Pipe Subgrade coupled with fluid and temperature field. Through numerical simulation, the effect mechanism and effect of the weak chain control technology are analyzed in detail. The change law of the temperature field of the subgrade is analyzed by studying the measured data of the temperature field in the test section of the ventilation tube subgrade, and the influence of wind speed in the pipe is further verified. The effect of the other external environment - slope, considering the effect of water content on its physical and mechanical properties after water ice phase change, compares the Janbu method, the Swedish strip method, the simplified Bishop method and the strength reduction method in the numerical analysis, and determines the Janbu method of the stability analysis of the high water cut (ice) clay slope in the permafrost region and combines the temperature. In the degree field calculation, the potential slip surface and the safety factor of the slope under different water content and 7 magnitude earthquake conditions are analyzed. A simple method is obtained for the stability analysis of high water cut (ice) clay slope in the frozen soil area.

【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U418.5

【参考文献】