加筋土挡墙临界高度研究

发布时间：2018-04-30 14:23

本文选题：加筋土挡墙 + 临界高度　；参考：《太原理工大学》2017年硕士论文

【摘要】：随着加筋体结构应用的逐步推广,人们对于加筋土挡墙的高度需求越来越大,因此加筋土挡墙的临界高度研究渐渐成为人们关注的一个重点问题,其研究方法主要包括:(1)传统塑性理论;(2)广义塑性理论;(3)极限分析法三种方法。目前基于这些方法进行的加筋土挡墙临界高度研究不少,但大多忽略了筋材与土体之间的摩擦损耗这一客观因素,致使研究结果难以与实际相吻合。本文以极限分析法为基础,通过分析加筋体作用机理,充分考虑了加筋土挡墙发生内部破坏时速度间断面上筋材和土体的能量损耗以及两者之间的摩擦损耗,推导出加筋土挡墙临界高度公式,并用多种方法进行验证。所做的主要工作及结论如下:(1)分析土体加筋机理及几种破坏模式,确定加筋体发生内部破坏时破裂面形态为对数螺旋面;(2)以武汉大学王钊教授研究思路为基础,基于极限分析法,认为加筋土挡墙发生内部破坏时,系统总的内部能量损耗率包括速度间断面上筋材和土体的能量损耗率以及两者之间由摩擦引起的能量损耗率。外功率由转动土体的重力提供。建立分析方程并推导出加筋土挡墙临界高度计算公式;(3)借鉴国外学者Porbaha A所做的模型试验参数,运用半图法对加筋土坡临界高度进行求解,并与试验结果对比,两者基本吻合,验证了考虑筋~土间摩擦损耗的加筋土挡墙临界高度公式的合理性;(4)参照模型试验参数,在Geo-Studio软件中的SLOPE模块建立分析模型,对加筋土挡墙进行逐层填筑,得出在临界状态(Fs=1)时加筋土挡墙的高度,与理论计算和模型试验结果基本吻合,进一步验证公式的合理性;(5)将加筋土挡墙临界高度公式应用于工程实际,结合研究区边坡设计相关参数,利用半图法对公式进行求解,计算得到相应设计条件下,将黄土作为填料时加筋土挡墙的最大高度为72.6 m,并选取小于该高度的典型剖面进行稳定性分析,结果满足规范要求,证明公式具一定的指导意义。
[Abstract]:With the gradual application of reinforced structure, the demand for the height of reinforced earth retaining wall is increasing. Therefore, the study of critical height of reinforced earth retaining wall has gradually become a key issue that people pay attention to. The research methods mainly include three kinds of methods: (1) traditional plastic theory and (2) Generalized plasticity theory (/ 3)) limit analysis method. At present, there are many researches on critical height of reinforced earth retaining wall based on these methods, but most of them ignore the objective factor of friction loss between reinforced material and soil, which makes the research results difficult to coincide with the actual situation. Based on the limit analysis method and by analyzing the mechanism of reinforced body, the energy loss of reinforcement and soil on the velocity discontinuous surface and the friction loss between them are fully considered in this paper when the internal failure of reinforced earth retaining wall occurs. The formula of critical height of reinforced earth retaining wall is derived and verified by many methods. The main work and conclusions are as follows: (1) analyzing the mechanism of soil reinforcement and several failure modes, determining that the shape of fracture surface is logarithmic spiral plane in the case of internal failure of reinforced body) based on the research ideas of Professor Wang Zhao of Wuhan University. Based on the limit analysis method, it is considered that the total internal energy loss rate of the system includes the energy loss rate of the steel bar and soil on the velocity discontinuous surface and the energy loss rate caused by friction between the reinforced earth retaining wall and the reinforced earth retaining wall. The external power is provided by the gravity of the rotating soil. The analysis equation is established and the formula for calculating critical height of reinforced earth retaining wall is deduced. The model test parameters made by foreign scholar Porbaha A are used for reference, and the critical height of reinforced soil slope is solved by using half graph method. The results are in good agreement with the experimental results. The rationality of the formula of critical height of reinforced earth retaining wall considering the friction loss between reinforcement and soil is verified. According to the parameters of the model test, the analysis model is established in the SLOPE module of Geo-Studio software, and the reinforced earth retaining wall is filled layer by layer. It is concluded that the height of reinforced earth retaining wall in critical state is in good agreement with the theoretical calculation and model test results, and the rationality of the formula is further verified. (5) the formula of critical height of reinforced earth retaining wall is applied to engineering practice. According to the parameters of slope design in the study area, the formula is solved by using the semi-graph method, and the corresponding design conditions are obtained. When loess is used as filler, the maximum height of reinforced earth retaining wall is 72.6 m, and the typical section less than this height is selected for stability analysis. The results meet the requirements of the code and prove that the formula has certain guiding significance.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU476.4

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