【作者】 赵峰；

【导师】 罗书学；

【作者基本信息】 西南交通大学 ， 建筑与土木工程， 2013， 硕士

【摘要】 随着我国铁路建设的快速发展,用碎石材料填筑路堤的情况越来越多,尤其在我国的西南山区。目前国内对铁路填石路堤的研究还比较少,具体的施工方法、沉降控制及质量检测标准等还不成熟、系统,主要是参考公路和水利堆石坝工程。填石路堤的沉降与稳定性是路堤安全中的重中之重,在施工过程中,影响填石路堤沉降与稳定性的因素很多,具体研究各工况和因素对填石路堤的影响十分必要,这对于控制路堤的工后沉降和保证列车的运营安全具有重要作用。本文主要依托“结合贵阳至广州铁路硬质岩石填料填筑路堤关键技术研究”课题,通过试验段现场填石路堤的填料选择标准、施工工序和质量控制等研究,并结合现场实测值与有限元模拟结果的对比分析,具体提出控制填石路堤沉降的施工工序要求以及施工过程应采取的措施。同时,借助于有限元分析软件建立了填石路堤的二维和三维计算模型,研究了各个因素和工况对填石路堤的受力、变形等力学特性的的影响大小和范围,并对路堤在列车动荷载作用下的应力和位移时程变化进行了分析,给出了一些供设计和施工参考的建议。本文取得的主要成果如下：1.在填石路堤的整个施工过程中,从最大限度的降低路堤工后沉降和满足安全稳定性角度出发,研究通过对填料选择、每一步施工工序的控制来满足路堤的质量要求。2.通过数值分析软件MIDAS/GTS建立了填石路堤的二维模型,模拟分析了五种不同粒径填料在列车荷载作用下路堤的稳定系数、各方向位移、最大应力应变。在相同的荷载、边界条件、施工条件下,SA、SB、SC这三种粒径较小的填料填筑的路堤处于较高稳定安全状态,位移较小。而SD、SE这两种较大粒径填筑的路堤虽然也处于稳定状态,但位移和应变较大,处于较低安全状态。3.填石路堤的稳定安全系数随着路堤边坡坡度的减小而增大,但幅度不大,路堤所受应力应变的变化也较小。在地基强度较小不满足受力要求时,进行地基处理是必要的,地下水位升降变化对填石路堤受力与变形几乎没有影响。4.通过对填石路堤填筑过程的分析,并对比实测值和有限元计算值,得到数值模拟的结果与试验所得结果是较为吻合的,说明有限元模拟填石路堤施工过程是可行的。5.列车动力荷载作用下的三维有限元模拟主要计算填石路堤在工后列车运行时,五种不同粒径填料路堤随列车行驶时间变化的受力、沉降及稳定性。主要进行路堤结构本身特征值和应力、位移时程分析。在填石路堤的动力分析中,不论是路堤某个部位的受力和变形,还是随时间变化的整个路堤的受力和变形,均能够满足列车运行的要求,路堤处于安全稳定状态。更多还原

【Abstract】 With rapid development of China railway construction, crushed stone is used more and more in roadbed construction, especially in mountainous areas of southwest China. Currently, there is little domestic research on rock-filled embankment. At the same time, methods of specific construction and the control of settlement are not perfect. The standard of quality inspection has been not set up yet. Builders often refer to the highway and water conservancy rock-filled dam project. Settlement and stability are absolutly important to rock-filled embankment. There are many factors which will affect the stability and settlement of rocked-filled embankment. It is necessary to research each specific construction conditions influencing on embankment. Similarly, It will play an important roles to controlling the post-construction settlement of rocked-filled embankment and the train safe operation.The thesis is mainly based on the key railway technologies research subject of Guiyang to Guangzhou hard rock-filled embankment. According to the scene of the test section construction, we plan to carry out the research including the selection criteria of rockfill, construction procedures and the quailty control. Moreover, we will compare the actual measured value with the results of the finite element method analysis as well as propose the specific construction procedures to control the settlement of the rock-filled embankment and which measures should be taken to. Meanwhile, with the aid of the finite element analysis software, we established the2D and3D calculation model of the rock-filled embankment and research some factors and conditions which wil influence the deformation and the scope of mechanical properties. Under the effects of train load, we have analysised the time history of the displacement and stress and also put forward some advice for the design and construction. The main results of the paper are as follows:1. The choice of rock fill and each step of embankment construction have been strictly controlled in the whole course of construction to reduce the post-construction settlement and meet the safety stability.2. The two-dimensional model was established by the numerical analysis MIDAS/GTS. Under the train load, rock-filled embankments which are consist of five different particle size of rockfill was simulated to analysis the stable safety factor, all directions of displacement and maximum stress and strain. Compare the smaller particle size with the bigger, it can be concluded that embankment is relatively in a more safety state under the same load, boundary conditions and construction conditions. 3. The safety stability factor of embankment increase modestly with the decrease of the embankment slope. This change is also suitable for the unit stress and strain. It is indispensable to foundation treatment when the strength of foundation does not meet the basic bearing capacity which is required in the norm. The underground water level at different height almostly has no effect on rock-filled embankment4. Through the construction stage analysis of rock-filled embankment and comparing the measured values with calculated values of finite element, we can get the result that the two values coincide. Engineering practice shows that the finite element simulation is feasible.5. During the period of the train operation, the three dimensional finite element simulation which was under the train dynamic load mainly computed the force, settlement and stability of rock-filled embankments which were composed by the five rockfill of different particles size. The purpose is to analysis the eigenvalue and the time history of stress and displacement. In general, according to the dynamic analysis of rock-filled embankment, whether the stress and deformation of nodes or the whole embankment both can satisfy the requirement during the train operation. The calculation results indicate that the rock-filled embankment is in a safe and stable state.更多还原