路桥过渡段路面结构开裂与差异沉降分布研究

Study on bridge-approach pavement cracking and differential settlement distribution

为研究桥台后路面结构对过渡段差异沉降的耐受能力,采用ABAQUS大型有限元软件建立了路桥过渡段路基路面力学行为计算的三维有限元模型.采用交通荷载的静力等效方法简化计算过程并计入交通荷载对过渡路段沉降的影响.为了准确地模拟填土非线性特性与路面材料的损伤开裂性能,分别采用修正Duncan-Chang模型以及ABAQUS混凝土Concrete Damaged Plasticity模型描述各材料的本构关系.根据有限元计算结果,分析得到了过渡路段路面结构应力与差异沉降的时空变化规律,以及差异沉降导致路面结构损伤裂纹扩展直至破坏的发展规律,并由此提出了路桥过渡段差异沉降结构性控制标准.

In order to study the durability of the pavement for the bridge-approach settlement,a 3D finite element model by ABAQUS finite element code is presented to investigate the mechanical behavior of pavement and sub-grade in the bridge-approach zone.An equivalent static traffic load is applied to simplify the FEA process and the effect of the traffic load on the bridge-approach settlement is reckoned in.In order to reasonably simulate the nonlinear behavior of the backfill and the cracking damage of the pavement materials,the modified Duncan-Chang model and the concrete damaged plasticity model in ABAQUS are implemented,respectively.Based on the results of FEA calculaion,the variation of the stress distribution and different settlement with time and space have been closely studied in bridge-approach zone.Then,the evolvement of the pavement cracking with the development of the bridge-approach settlement in transition zone is also deduced from the calculations by using ABAQUS standard module.Accordingly,a structural design criterion of bridge-approach settlement has been proposed.