多年冻土区级配改良结构性路基热学机制

来源期刊：中南大学学报(自然科学版)2006年第3期

论文作者：胡建华 汪稔 胡明鉴 周科平

文章页码：600 - 606

关键词：多年冻土;级配改良;结构性;有限元

Key words：permafrost; improved gradation; structure; finite element method

摘    要：提出在青藏高原多年冻土上修建路基的一种新型结构———级配改良结构性路基,即通过路基填土的粒径级配重组和水平排水板的结构改良,改善路基的热效应,并建立级配改良结构性路基模型;根据粗砾石的Balch效应和级配改良粗粒层自然对流效应,分析级配改良结构性路基保护多年冻土的热学工作机制;依据级配改良结构性模型路基的尺寸和热力学参数,采用有限元数值分析方法,建立有限元分析模型。在年增温率为0.04℃/a条件下, 20 a内级配改良结构性路基与地质体的温度场有利于冻土保护,路堤冻土上限抬升后的变化幅度与天然场地冻土上限的下降幅度一致,有利于减小不均匀的融沉变形,减少路基不均匀沉降开裂。研究结果表明,级配改良结构性路基具有良好的保护冻土的功能,是一种简单有效的路基结构形式。

Abstract: A new type of the embankment structure was put forward in the permafrost regions of Qinghai-Tibet plateau, which was the improved graded structural embankment, and whose ther-mo-effect was amended by reconstructing the size grading and the horizontal plastic drain. The embankment model was built, and the thermo-mechanism was studied to protect permafrost by the effects of Balch and natural convection in the coarse gravel layer. Using the finite element method, the law and the change of the temperature filed was analyzed in the future 20 a in the improved graded structural embankment and the geologic body, under the condition that the temperature is increases by 0.04℃/a. The scope for change of the permafrost table corresponds with the natural land, and it can decrease the thawing deformation and the fracture. The results show that the improved graded structural embankment can protect the permafrost effectively, and it is a simple structure type to the improved graded structural embankment.

基金信息：中国科学院知识创新工程重大项目