研究目的:客运专线对施工后的路基沉降控制要求非常严格，允许的工后沉降量特别小。武广客运专线 武汉至韶关段分布有长达I00 km的红黏土路段，红黏土的变形特性可能对路基变形和边坡稳定产生不良影 响，为避免施工后的路基边坡失稳和不均匀沉降等灾害，对红黏土的变形特性，从红黏土的应力-应变关系、 固结变形和胀缩变形3个方面进行研究，提出控制红黏土的变形措施及改善其工程特性的方法。
研究结论:以武广客运专线工程实例为背景，通过大量的室内三轴试验，固结试验，胀缩实验等，研究了红 黏土的应力-应变特性、固结变形特性和胀缩变形特性，发现红黏土具有超固结性、固而不密，固结反剖面特 性，中等压缩性，其膨胀性较小而收缩性较强等变形特性。对红黏土路段，可通过优化红黏土的粒径分布来减 小红黏土的变形;采用足够大的荷载抑制红黏土地基的膨胀。在红黏土路段施工时，可采用CFG桩加固地 基，采用桩板墙和锚杆加固边坡等措施，这对于客运专线实体工程的修建具有十分重要的指导意义，并可为类 似工程提供借鉴作用。
Research purposes: Passenger dedicated line has strict deformation control after construction with very small amount. Along Wuhan-Guangzhou passenger dedicated line, extremely large area of red clay exists which covers more than 100km, from Wuhan to Shaoguan. And the harmful effects which red clay might bring to foundation deformation and slope stability. In order to avoid these results, red clay deformation characteristics were studied in 3 aspects, such as stress-strain relation，consolidation deformation and swell-shrinking deformation. Finally, the deformation control methods and engineering properties improvement were put forward.
Research conclusions: Take the entity project of Wuhan-Guangzhou passenger dedicated line for example，a lot of indoor tests, such as triaxial tests, consolidation tests, expansion tests and contraction tests were carried out. The characteristics of red clay including stress-strain relationship, consolidation deformation behavior, and expansive- contractive deformation behavior were studied. The following characteristics of red clay were obtained: behavior of ultra- consolidation characteristic, behavior of consolidation but without compassion, consolidation and anti-profile characteristic, medium compression, relative less expansive deformation and more contractive deformation. In red clay areas, we could improve the particle size distribution of red clay to reduce its deformation; use heavy load to constrain its expansion. During construction, CFG piles could be used to strengthen the foundation and pile-plank wall，as well as bolts could be adopted to strengthen slopes. These are of great significance to the construction of entity project of passenger dedicated line and provide references for similar projects
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