旧水泥混凝土路面直接加铺沥青层结构分析

发布时间：2018-01-08 15:01

本文关键词：旧水泥混凝土路面直接加铺沥青层结构分析　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：在行车荷载和外界环境因素的反复作用下，水泥混凝土路面的使用性能逐渐衰变，营运一段时期后，路面使用性能及其承载能力可能不再满足交通需求。采取在旧水泥混凝土路面上直接加铺沥青层的方法进行修复，能够有效利用旧水泥混凝土路面的剩余强度，改善路面的使用性能。针对旧水泥混凝土路面上直接加铺沥青层结构容易产生反射裂缝的特点，结合研究所依托的益常高速公路改建项目情况，本文分别建立了接缝处设传力杆的水泥混凝土路面三维有限元模型和旧水泥路面上直接加铺沥青层三维有限元模型，，分别对水泥路面接缝处板边弯沉的影响因素、沥青加铺层裂缝尖端附近力学特征和反射裂缝在加铺层中的疲劳扩展寿命预测等问题进行深入研究。主要研究内容包括：（1）研究接缝处设传力杆的旧水泥混凝土路面接缝处板边弯沉，重点分析水泥混凝土路面各结构层模量的变化对接缝处弯沉及弯沉差产生的影响。以旧水泥混凝土路面处治质量要求（板边弯沉值U 0.2mm，弯沉差U0.06mm）为依据，考虑各结构层参数变化情况，研究合适的结构层模量组合，以便于后续的沥青加铺层结构分析。（2）以断裂力学理论为路基，采用有限元方法分析裂缝扩展至沥青加铺层各细分层中部时的型裂缝尖端应力强度因子K M1、K M2、K M3随相关结构层模量变化的规律。（3）选取适合于实际情况的路面结构层模量组合，确定行车荷载作用下裂缝扩展至沥青加铺层各细分层中部时的裂缝尖端应力强度因子、、，以此代表反射裂缝贯穿各细分层时应力强度因子的平均水平，利用Paris公式建立行车荷载下沥青加铺层疲劳寿命预估模型，计算满足给定条件的沥青加铺层疲劳寿命。
[Abstract]:Under the repeated action of driving load and external environmental factors, the performance of cement concrete pavement gradually decays, after a period of operation. The pavement performance and its bearing capacity may no longer meet the traffic demand. The method of directly overlaying asphalt layer on the old cement concrete pavement can effectively utilize the residual strength of the old cement concrete pavement. Improve pavement performance. In view of the characteristics that direct overlay asphalt layer structure on the old cement concrete pavement is prone to produce reflective cracks, combined with the case of Yi-Chang Expressway reconstruction project supported by the Institute. In this paper, three dimensional finite element model of cement concrete pavement with force transfer bar at joint and three dimensional finite element model of asphalt layer directly overlaid on old cement pavement are established. The influence factors of the plate side deflection at the joint of cement pavement are discussed respectively. The mechanical characteristics near the crack tip of asphalt overlay and the prediction of fatigue propagation life of reflection crack in the overlay are studied in depth. The main research contents are as follows: 1) study the side deflection of the plate at the joint of the old cement concrete pavement with the force transfer rod at the joint. The influence of deflection and deflection difference at the butt joint of cement concrete pavement is analyzed emphatically. The quality requirement of treating the old cement concrete pavement (the deflection value of slab side is U 0.2 mm) is analyzed. On the basis of deflection difference U0.06mm), considering the variation of structural layer parameters, the suitable combination of structural layer modulus is studied in order to facilitate the subsequent analysis of asphalt overlay structure. (2) taking the theory of fracture mechanics as subgrade, finite element method is used to analyze the stress intensity factor (KM1KM2) at the crack tip when crack extends to the middle of each subdivision layer of asphalt overlay. The variation of K M 3 with the modulus of related structure layer. The stress intensity factor of crack tip is determined when the crack extends to the middle of each subdivision layer of asphalt overlay under the action of driving load by selecting the pavement structure layer modulus combination which is suitable for the actual situation. On behalf of the average level of stress intensity factor when reflection cracks run through each subdivision layer, the prediction model of fatigue life of asphalt overlay under traffic load is established by using Paris formula. The fatigue life of asphalt overlay is calculated.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.2

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