山区沿河公路悬空路面板三维断裂机制研究
发布时间：2018-10-31 11:33
【摘要】：西南地区主要为山地丘陵地貌,夏季降雨丰沛,为山洪、泥石流等地质灾害的孕育创造了地理优势。沿河公路依山傍水,地质灾害频发,公路洪灾损失严重,混凝土悬空路面板即是公路水毁典型形式中的一种常见形态。本文以沿河公路悬空路面板为研究对象,利用复合材料等效原理、有限元模拟、弹性地基薄板理论、断裂力学、材料力学等知识,分析其在自重和车辆荷载作用下的三维断裂破坏机制。根据路面板悬空程度,结合路面裂纹状况,得出了混凝土悬空路面板的极限承载力,并据此划分出安全行车区域,通过交通管制,限定通行车辆荷载和通行区域,防止悬空混凝土路面板发生突然的脆性断裂破坏,以保障人民生命财产安全。取得主要成果如下:(1)基于复合材料理论,采用细观力学的方法,以混凝土悬空路面板裂纹扩展规律为依据,得出了并串联模型和串联体模型两种等效混凝土弹性模量预估计算方法,在优化的基础上实现了将钢筋混凝土悬空路面板等效为均质板的过程,为有限元分析和理论分析提供支撑。(2)运用ANSYS有限元模拟,对平行悬空和角部悬空混凝土路面板进行数值模拟,考虑悬空比例、车辆轴载、车辆荷位的因素,分析其应力场分布,获得了最大拉应力分布规律和最不利车辆荷位,为理论分析奠定基础。(3)基于Winkler弹性地基薄板理论,借鉴Westerggard分析无限大板荷载应力思路,将平行悬空路面板通过力学简化处理,转化为非悬空有限尺寸路面板模型,进一步求得受剪面上拉应力公式。(4)按照断裂力学方法,采用带表生裂纹的三维断裂模型,求得平行悬空路面板在自重和车辆荷载作用下的极限承载力公式。(5)按照材料力学的方法计算刚性路面荷载应力,得到了角部悬空路面板拉应力计算公式,结合断裂力学的方法,采用带表生裂纹的三维断裂模型,求得角部悬空路面板在自重和车辆荷载作用下的极限承载力公式。
[Abstract]:The southwest area is mainly mountainous and hilly geomorphology with abundant rainfall in summer, which creates geographical advantages for geological disasters such as mountain torrents and debris flows. The highway along the river is leaning against the mountain and water, geological disasters occur frequently, the flood damage of the highway is serious, and the concrete suspended slab is one of the typical forms of highway water damage. Based on the theory of composite equivalent, finite element simulation, thin plate theory of elastic foundation, fracture mechanics, material mechanics, etc. The three-dimensional fracture failure mechanism under the action of deadweight and vehicle load is analyzed. According to the suspended degree of the pavement slab and the crack condition of the pavement, the ultimate bearing capacity of the concrete suspended pavement slab is obtained, and the safe driving area is divided according to this, and the traffic load and the traffic area are limited by traffic control. In order to protect the life and property of the people, it can prevent the sudden brittle fracture and damage of the suspended concrete pavement slab. The main achievements are as follows: (1) based on the theory of composite materials, the method of meso-mechanics is adopted, and the law of crack growth of concrete suspended pavement slab is taken as the basis. In this paper, two kinds of equivalent concrete elastic modulus estimation methods, parallel series model and series body model, are obtained. On the basis of optimization, the process of equating reinforced concrete suspended slab to homogeneous slab is realized. It provides support for finite element analysis and theoretical analysis. (2) using ANSYS finite element simulation, the parallel suspension and corner suspension concrete pavement are numerically simulated, considering the factors of suspension ratio, vehicle axle load, vehicle load position, etc. The maximum tensile stress distribution law and the most unfavorable vehicle load position are obtained by analyzing the stress field distribution. (3) based on the Winkler elastic foundation thin plate theory, Westerggard is used to analyze the load stress of infinite plate. The parallel suspended road slab is simplified by mechanics and transformed into a non-suspended finite size road panel model, and the formula of tensile stress on the shear plane is obtained. (4) according to the method of fracture mechanics, the three-dimensional fracture model with apparent crack is adopted. The formula of ultimate bearing capacity of parallel suspended road slab under the action of deadweight and vehicle load is obtained. (5) according to the method of material mechanics, the load stress of rigid pavement is calculated, and the formula for calculating tensile stress of corner suspended road slab is obtained. Combined with the method of fracture mechanics, a three-dimensional fracture model with surface crack is used to obtain the ultimate bearing capacity formula of the corner suspended road slab under the action of deadweight and vehicle load.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U418.54
本文编号：2302034
[Abstract]:The southwest area is mainly mountainous and hilly geomorphology with abundant rainfall in summer, which creates geographical advantages for geological disasters such as mountain torrents and debris flows. The highway along the river is leaning against the mountain and water, geological disasters occur frequently, the flood damage of the highway is serious, and the concrete suspended slab is one of the typical forms of highway water damage. Based on the theory of composite equivalent, finite element simulation, thin plate theory of elastic foundation, fracture mechanics, material mechanics, etc. The three-dimensional fracture failure mechanism under the action of deadweight and vehicle load is analyzed. According to the suspended degree of the pavement slab and the crack condition of the pavement, the ultimate bearing capacity of the concrete suspended pavement slab is obtained, and the safe driving area is divided according to this, and the traffic load and the traffic area are limited by traffic control. In order to protect the life and property of the people, it can prevent the sudden brittle fracture and damage of the suspended concrete pavement slab. The main achievements are as follows: (1) based on the theory of composite materials, the method of meso-mechanics is adopted, and the law of crack growth of concrete suspended pavement slab is taken as the basis. In this paper, two kinds of equivalent concrete elastic modulus estimation methods, parallel series model and series body model, are obtained. On the basis of optimization, the process of equating reinforced concrete suspended slab to homogeneous slab is realized. It provides support for finite element analysis and theoretical analysis. (2) using ANSYS finite element simulation, the parallel suspension and corner suspension concrete pavement are numerically simulated, considering the factors of suspension ratio, vehicle axle load, vehicle load position, etc. The maximum tensile stress distribution law and the most unfavorable vehicle load position are obtained by analyzing the stress field distribution. (3) based on the Winkler elastic foundation thin plate theory, Westerggard is used to analyze the load stress of infinite plate. The parallel suspended road slab is simplified by mechanics and transformed into a non-suspended finite size road panel model, and the formula of tensile stress on the shear plane is obtained. (4) according to the method of fracture mechanics, the three-dimensional fracture model with apparent crack is adopted. The formula of ultimate bearing capacity of parallel suspended road slab under the action of deadweight and vehicle load is obtained. (5) according to the method of material mechanics, the load stress of rigid pavement is calculated, and the formula for calculating tensile stress of corner suspended road slab is obtained. Combined with the method of fracture mechanics, a three-dimensional fracture model with surface crack is used to obtain the ultimate bearing capacity formula of the corner suspended road slab under the action of deadweight and vehicle load.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U418.54
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