导　　师： 刘赟

学科专业： H1402

授予学位： 博士

作　　者： ;

机构地区： 东北大学

摘　　要： 排泄公路两侧冲沟、溪流的洪水,在不过水时也可作交通使用,单孔跨径小于5m的称为涵。涵洞/(管/)被广泛地应用于公路、铁路、市政、军工等行业和部门,是“生命线工程”之一种。过去,我国公路中涵洞多为低填,涵洞设计依据规范就可以满足要求。但按照国家公路发展总体目标,我国公路建设投资不断加大、公路等级明显提高,公路中的高填土涵洞结构物所占比重也是越来越大。日益增多的高填土涵洞,缺乏相应的配套理论为指导,导致在实际中暴露出许多问题。所以,高填土涵洞研究有着重要的社会意义。本文采用相似材料模型试验、有限元数值模拟相结合的方法对决定高填土涵洞结构设计的荷载-垂直土压力进行研究,得出垂直土压力分布；不同标高土层的沉降位移分布。在此基础上,建立高填土涵洞垂直土压力计算公式。测试涵洞结构应力分布,探讨涵洞病害原因。采用自行编制的自适应遗传算法-神经网络系统对涵洞断面测点变形/(应力/)进行预测。具体的研究内容如下所述： /(1/)依据相似定理,量纲分析法导出相似指标,作为试验相似与否的判定标准。对比试验确定砂、石膏和硅藻土的混合物为相似材料,得出用水量、砂膏比、膏土比和养护条件与材料力学参数的关系。用相似材料,按几何相似比,制成拱涵和盖板涵的小比例模型,代替其他人采用的有机玻璃、木块制作涵洞模型,可以更加真实反应涵洞结构受力。 /(2/)对试验箱内涵洞模型逐层填土、千斤顶逐级加载模拟实际施工过程,土压力计测试涵洞填土层的应力变化。填土高度增加,垂直土压力及其增长速度都呈现非线性增长。填土高度较低时,施工荷载和刚度差异引起附加应力作用；填土达到一定高度后,应力重分布产生土拱效应,两者共同影响决定垂直土压力分布。模型试验、结 Culvert is mainly used to discharge water from gulley and stream in two sides of road. Culvert can also traffic without water. Span length is less than 5 meters. Culvert is one of lifeline projects, and frequently occurs in the regions where there is no abundant river water or shallow groundwater, such as traffic, highway, railway, municipal works and war industry, etc. An efficient development of water resources in such regions is an important problem for transportation. Culvert is positive buried structure, and its design is guided by norm when the fill on culvert is low in the past. With the development of China highway, highroad grade criterion increased, and the proportion of culvert with high fill is greater. However, under this situation, High filled culvert designed without the reasonable theory instruction, which leads to some of them fail in the period of construction or after completion of work. So research about vertical earth pressure acting on high filled culvert is significant in engineering and society development. Considering some different influencing factors, modest tests and numerical simulation are performed to analyse vertical earth pressure distribution rule and fill layer displacement field. Using of culvert structure's measure data from model test as sample, programmed AGA-BP /(adaptive genetic algorithm-back propagation network/) system are developed to forecast culvert section stress. The contents of research in the paper as follow, /(1/) Based on similarity theory and some experimental results, a renew criterion was firstly put forward to judge rationality whether the test result as to a similarity index. Intermixture with sand, gypsum and diatomite as raw material specimens, tests with different similarity modeling material were performed. The relations among four influencing factors including water quantity, ratio of sand and gypsum, ratio of gypsum and diatomite, curing condition with material mechanical properties were got. According to geometric similarity ratio, similar mate

关 键 词： 高填土涵洞 垂直土压力 相似指标 相似材料模型试验 数值模拟 土拱效应 优化设计 标准遗传算法 自适应遗传算法 网络 自适应遗传算法 神经网络系统 预测

领　　域： [建筑科学] [交通运输工程] [建筑科学]