玛查理至柯曲公路工程多年冻土路基设计方案研究

发布时间：2019-02-12 20:25

【摘要】：多年冻土一直是影响青藏高原地区公路路基稳定性的主要因素,近年来,全球气候整体变暖,这一变化加速了冻土融化。同时冻土区人类活动也加重了冻土负担,加速其退化,进而影响到该地区公路路基的稳定性。因此,针对不同地区,制定不同的冻土路基设计方案,对于多年冻土区公路的建设具有重要的意义。本文首先分析了多年冻土地区路基的主要病害及其成因,指出纵向裂缝、热融沉陷、冻胀翻浆是多年冻土地区路基病害的主要形式,并分析其成因主要有多年冻土的特殊性、恶劣自然环境和人为因素。在此基础上论述了多年冻土路基的设计体系。指出进行多年冻土区路基设计时,须遵循以下原则:保护冻土、保持多年冻土融沉速率、预融冻土等。最后,本文依托“玛查理至柯曲公路工程”,对多年冻土路基设计方案进行研究分析,主要针对路基设计、技术调控、质量控制等进行了研究,并强调设计中的注意事项。片石块石路基因其通风性好,易于冻土温度调节,所以可以应用于冻土路基填筑中。热棒作为稳定冻土最有效的工程手段,被广泛应用于冻土区公路建设中。当外界温度和热棒埋设的路基内部温差达到热棒工作温差时,热棒自动开始工作。热棒内部工质在冻土层吸收热量,蒸发气化后上升至外露端,放热冷凝后下降至冻土端,如此循环往复可达到保护冻土稳定的目的。
[Abstract]:Permafrost is the main factor that affects the stability of highway roadbed in Qinghai-Tibet Plateau. In recent years, the global climate has become warmer, which accelerates the thawing of frozen soil. At the same time, human activities in permafrost region also increase the burden of frozen soil, accelerate its degradation, and then affect the stability of highway roadbed in this area. Therefore, it is of great significance for highway construction in permafrost regions to formulate different design schemes for permafrost subgrade. This paper first analyzes the main diseases and causes of roadbed in permafrost regions, and points out that longitudinal cracks, thermal thawing subsidence and frost heaving are the main forms of roadbed diseases in permafrost regions, and the main causes are particularity of permafrost. Adverse natural environment and human factors. On this basis, the design system of permafrost subgrade is discussed. It is pointed out that the following principles should be followed in roadbed design in permafrost regions: protecting permafrost, maintaining thawing rate of permafrost, prethawing frozen soil and so on. Finally, based on the "MaCharlie to Ke qu Highway Project", this paper studies the design scheme of permafrost roadbed, mainly for the roadbed design, technical control, quality control and so on, and emphasizes the matters needing attention in the design. Because of its good ventilation and easy to adjust the temperature of frozen soil, it can be used in the filling of permafrost roadbed. As the most effective engineering method to stabilize frozen soil, hot bar is widely used in highway construction in frozen soil area. When the outside temperature and the temperature difference inside the roadbed buried by the hot rod reach the working temperature difference of the hot rod, the hot bar will start to work automatically. The internal working fluid of the heat rod absorbs heat in the frozen soil layer, rises to the exposed end after evaporation and gasification, and then decreases to the frozen soil end after the exothermic condensation, so the cycle reciprocating can achieve the purpose of protecting the stability of the frozen soil.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.1

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