加筋路堤边坡变形及承载特性研究

发布时间：2018-03-28 13:26

本文选题：加筋土边坡　切入点：变形特征　出处：《兰州交通大学》2015年硕士论文

【摘要】：加筋土是在土体内加入较强抗拉性能土工合成材料组成的复合土。随着我国经济与交通运输业的快速发展,加筋土技术将越来越多的应用在路堤的修建中,用来提高路堤的承载力与稳定性,并控制路堤变形。研究加筋路堤变形特性与承载力特性对加筋加筋土的工程应用及相关研究有重要意义。本文以某公路路堤为原型,首先通过理论分析计算了加筋路堤边坡稳定性系数,得出不同因素对路堤边坡稳定性的影响。而后采用室内模型试验以及三维数值模拟的方法,研究路堤边坡在不同工况时的变形与承载力特性以及土体内附加应力分布、筋材受力分布及路堤破裂面形态的规律特征。通过分析得出以下结论:(1)运用所提出的理论公式,得出未加筋、二层水平加筋、二层立体加筋路堤边坡的稳定性系数呈增长态势,另外立体加筋路堤中竖筋高度的增加也能够使边坡稳定性系数明显提高。(2)通过室内试验发现筋材层数的增加会使边坡极限承载力增大、坡顶沉降减小,而相同情况下立体加筋路堤相对于水平加筋路堤有着更大的极限承载力与更小的坡顶沉降量,同时发现立体加筋的竖筋高度会对路堤承载力与沉降方面有着较明显的影响。(3)随着路堤筋材层数增加或立体筋材竖筋高度增大都会使路堤边坡的侧向变形减小。观测实验中路堤破裂面形态之后发现到不论是水平加筋还是立体加筋路堤,其破裂面形态都不同于未加筋路堤,破裂面被筋条隔断为多个圆弧面。(4)极限荷载作用下加筋路堤随内附加应力随着筋材层数的增加而增大,但相同层数布筋条件下立体加筋路堤附加应力大于传统水平加筋路堤。(5)相同荷载作用下随着加筋层数增多筋条上所受的会随之减小,同时靠近路堤顶面筋材的变化率较大,远离路堤顶面的筋材,拉力的变化率逐渐减小,曲线逐渐平缓。(6)通过数值模拟在坡顶沉降与筋材受力方面与模型试验结果相互验证,得出与模型试验相同结论。以上结论可为加筋路堤边坡的设计和施工提供参考和技术支持
[Abstract]:Reinforced soil is a composite soil with strong tensile properties. With the rapid development of economy and transportation in China, reinforced soil technology will be used more and more in the construction of embankment. To improve the bearing capacity and stability of embankment and to control the deformation of embankment. The study of deformation and bearing capacity characteristics of reinforced embankment is of great significance to the engineering application of reinforced soil and related research. In this paper, a highway embankment is used as prototype. Firstly, the stability coefficient of reinforced embankment slope is calculated by theoretical analysis, and the influence of different factors on the stability of embankment slope is obtained. The characteristics of deformation and bearing capacity of embankment slope under different working conditions, the distribution of additional stress in soil, the stress distribution of steel bar and the shape of breakage surface of embankment are studied. It is concluded that the stability coefficient of the embankment slope with no reinforcement, two layers of horizontal reinforcement and two layers of three-dimensional reinforced embankment shows an increasing trend. In addition, the increase of vertical reinforcement height in stereoscopic reinforced embankment can also increase the slope stability coefficient obviously.) through laboratory tests, it is found that the increase of reinforcement layer will increase the ultimate bearing capacity of the slope and decrease the settlement of the slope top. Under the same condition, the three-dimensional reinforced embankment has greater ultimate bearing capacity and smaller slope top settlement than the horizontal reinforced embankment. At the same time, it is found that the vertical reinforcement height of the embankment has obvious influence on the bearing capacity and settlement of the embankment. 3) the lateral deformation of the embankment slope will be reduced with the increase of the number of reinforcement layers or the height of the vertical reinforcement of the embankment. After observing the breakage surface morphology of the embankment in the experiment, it is found that the embankment is reinforced horizontally or stereoscopically. The fracture surface of the embankment is different from that of unreinforced embankment. Under the action of limit load, the reinforced embankment increases with the increase of the number of reinforced layers. However, the additional stress of three-dimensional reinforced embankment is greater than that of the traditional horizontal reinforced embankment under the condition of the same layer number of reinforcement.) under the same load, with the increase of reinforced layer, the stress on the reinforced bar will decrease, and the change rate of gluten material near the top of the road embankment will be larger than that of the traditional horizontal reinforced embankment. Far from the top surface of the embankment, the change rate of tensile force decreases gradually, and the curve is gradually flat. 6) through numerical simulation, the settlement of the slope top and the stress of the steel bar are verified with the model test results. These conclusions can provide reference and technical support for the design and construction of reinforced embankment slope.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.12

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