有限填土路基对挡土墙的土压力研究

发布时间：2018-06-18 23:29

本文选题：挡土墙 + 有限填土路基　；参考：《郑州大学》2014年硕士论文

【摘要】：在公路建设中，受地形条件的限制会不可避免地修建半填半挖路基。为了保证半填半挖路基的稳定性，往往需要修建路基挡土墙。挡土墙设计中关键的问题是土压力的计算，其合理与否将直接影响到公路的安全性。半填半挖路基挡土墙后填土属于有限填土，其作用在挡土墙上的压力属于有限土体的压力。目前在挡土墙的设计中一般计算有限填土的主动土压力，但是对于有限填土要达到主动土压力需要一定的位移条件，而实际工程中有些挡土墙并没有产生足够的位移使有限填土达到主动土压力状态。对于有限填土主动土压力的计算，按照目前规范中的方法只能求得有限填土对挡土墙的合力，而不能明确有限填土主动土压力沿墙背的分布。库伦土压力理论假设填土对挡土墙土压力的分布为直线分布，但是一些实测结果表明填土对挡土墙土压力沿墙背的分布并非如此。本文的主要研究内容为： 1.基于已激发内摩擦角的概念，通过对挡土墙后填土应力莫尔圆的分析，建立半无限填土路基对挡土墙静止土压力的计算方法，考虑挡土墙背和基岩开挖面的影响，建立有限填土路基对挡土墙静止土压力的计算方法，并与规范中主动土压力的计算方法进行对比。针对不同接触面摩擦系数的各种情况，分别建立静止土压力系数的计算公式。 2.采用水平层分析法，考虑填土运动相关联流动法则，在挡土墙平移模式下，，建立半无限两层填土对挡土墙主动土压力的计算公式；针对分层有限填土路基挡土墙，考虑基岩开挖面对填土滑裂的影响，建立有限两层填土对挡土墙主动土压力的计算公式。 3.使用ANSYS软件，进行有限填土路基对挡土墙土压力的数值模拟，分别计算有限填土对挡土墙的静止土压力和主动土压力，分析有限填土路基对挡土墙土压力的大小及分布，并且详细分析填土内摩擦角、填土与接触面的摩擦系数、基岩开挖面倾角对土压力的影响。
[Abstract]:In highway construction, it is inevitable to build subgrade with half fill and half excavation due to the limitation of terrain condition. In order to guarantee the stability of half-filled and half-excavated subgrade, it is often necessary to build embankment retaining wall. The key problem in retaining wall design is the calculation of earth pressure, which will directly affect the safety of highway. The pressure acting on the retaining wall belongs to the limited soil pressure. At present, the active earth pressure of limited fill is generally calculated in the design of retaining wall, but the displacement condition is necessary for the limited fill to reach active earth pressure. However, some retaining walls do not produce enough displacement to make the limited fill reach the active earth pressure state. For the calculation of active earth pressure of limited fill, according to the method in the present code, the resultant force of limited fill on retaining wall can only be obtained, but the distribution of active earth pressure of limited fill along the back of wall can not be clearly defined. Coulomb's earth pressure theory assumes that the distribution of earth pressure on retaining wall is linear, but some measured results show that the distribution of earth pressure of fill to retaining wall along the back of the wall is not the same. The main contents of this paper are as follows: 1. Based on the concept of excited angle of internal friction, a method for calculating the static earth pressure of retaining wall with semi-infinite filling subgrade is established by analyzing the moire circle of filling stress in the back of retaining wall, considering the influence of the back of retaining wall and the excavating surface of bedrock. The calculation method of static earth pressure of retaining wall by finite fill subgrade is established and compared with that of active earth pressure in code. According to the friction coefficient of different contact surfaces, the formulas for calculating the coefficient of static earth pressure are established. 2. By using horizontal layer analysis method and considering the law of associated flow of fill movement, a formula for calculating active earth pressure of retaining wall with semi-infinite two layers of fill is established under the mode of lateral displacement of retaining wall, and the formula for retaining wall of layered and finite filling subgrade is established. Considering the influence of excavation of bedrock on the slip of fill, a formula for calculating the active earth pressure of retaining wall with finite two layers of fill is established. Using ANSYS software, the numerical simulation of the earth pressure of the limited fill subgrade to the retaining wall is carried out, the static earth pressure and the active earth pressure of the limited fill on the retaining wall are calculated respectively, and the magnitude and distribution of the earth pressure of the limited fill subgrade to the retaining wall are analyzed. The influence of the friction angle, the friction coefficient between the fill and the contact surface and the dipping angle on the earth pressure is analyzed in detail.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1;U417.11

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