【作者】 厉琳琳；

【导师】 魏星；

【作者基本信息】 西南交通大学 ， 岩土工程， 2013， 硕士

【摘要】 大准线作为我国第二条开行万吨列车的重载铁路,自运营以来,随着运量的逐年增加,线桥设备的破坏程度日益增大,冻害、翻浆冒泥、路基下沉等病害日益突出。其中部分路段由于排水不畅,病害尤为严重,基床的强度和稳定性已很难保证列车的安全与稳定运行。而大准线承担着繁重的煤运任务,因此,寻求一种在基本不影响运营情况下的病害路段治理方案,以保证列车安全运行是十分必要的。本文以大准线K37+400-640段路基加固为研究对象,利用土力学、复合地基理论、数值计算等理论和方法,研究了路基的受力特性,提出了路基加固方案,主要取得了以下研究成果：首先,论文结合现场探地雷达检测报告,分析了大准线病害路段路基的状况,探讨了K37+400-640段路基病害产生原因及机理。通过分析发现,大准线路基出现病害的主要原因有：原有路基土软弱、冻融循环、排水沟失效以及循环重载。其次,了解常用的路基病害整治方案,针对大准线病害情况对路基采用斜向灰土桩加固,并恢复排水系统。斜向灰土桩的加固方案可在列车限界外施工,不影响线路的运营,整体施工效率高。但因倾斜桩桩体自身承载、桩体与土体间相互作用关系,与竖直桩体相比要复杂的多,所构成的复合路基也难以用简单解析表达式来描述,可用数值方法来验证其加固效果。本文拟先运用复合地基理论设计出可行的竖向灰土桩加固方案,为斜向桩加固方案提供参照。再次,采用数值方法计算,分析了斜向桩加固方案,并与竖向桩加固方案进行了对比,基于分析的路基变形和应力比较二者的加固效果,从而证明斜向桩和竖向桩都可以取得良好的加固效果,且斜向桩更优。最后,在证明斜向桩是一种有效的加固方案的基础上,考虑实际工程运用时,保证加固效果的同时还要兼顾经济合理,论文进一步对斜向灰土桩的倾斜角度、灰土配合比和纵向桩排距对加固效果的影响进行了分析,并给出了斜向桩的优化加固方案。更多还原

【Abstract】 Da Zhun railway is our second heavy haul railway that running trains with ten thousand tons cargo.With the increase of traffic volume year by year, the damage to line bridge equipment becomes more and more seriously since the operation, the subgrade disease such as harmful freez, mud pumping, subgrade settlement are increasingly prominent. Owing to the poor drainage system of some sections, the disease are particularly serious, leading to the strength and stability of the subgrade has been difficult to guarantee the safety and stability of the operation. And it bears the heavy coal transport task, therefore, seeking a treatment that can deal with the disease without affecting the operation is very necessary.In this paper, the subgrade of K37+400-640section is taken as an example. The paper studies the mechanical behavior of subgrade according to the theory of soil mechanics and composite foundation, the method of numerical simulation etc., the treatment is proposed, the main results are obtained as followings:First, through the on-site GPR detection report, learning the subgrade disease present situation of railway subgrade disease, and analyzing the cause of the disease.Second, basing on the analysis of the common treatments to these ill roadbeds used in the existing railway line, the oblique lime-soil compaction piles treatment is introduced, But at present, the calculation theory about the oblique piles isn’t perfect, it can’t prove its feasibility in theory but by using numerical simulation.So, the upright piles treatment is designed through the composite foundation theory. It can provide a reference for the oblique piles treatment.Again, the reinforcement scheme of the oblique piles and upright piles are calculated by using numerical simulation, and Analysis on their reinforcement effects from the deformation and stress.The comparison results show that the oblique piles is more better.Finally, when used in the practical engineering, to ensure the reinforcement effect as well as economical, so this paper also optimize the angle of oblique piles, lime soil mixture ratio and the vertical distance of piles.更多还原