旧路拓宽全过程三维有限元分析

THREE-DIMENSIONAL NUMERICAL SIMULATION OF PAVEMENT PERFORMANCE IN WIDENED ROADS

旧路拓宽是西部山区高等级公路建设中的重要课题。运用岩土工程专业软件包P laxis 3D Tunnel,对旧路拓宽进行了全过程的三维弹塑性有限元数值模拟,包括新路基的填筑,路面各结构层的铺筑及轮载最不利位置的施加等,重点分析了新旧路基不均匀沉降变形及应力分布的规律,比较了拓宽方式、新老路基土模量差异对路面变形和使用寿命的影响,并就实际施工提出了一些建议。

Pavement performance in widened roads has been a great concern for highway engineers in road -widening - related design and construction projects in western China since the fast implementation of West Development Strategy several years ago. The 3D finite element method （FEM） was used to simulate the construction and operation process of flexible pavements with Plaxis 3D Tunnel, a geotechnique -tailored commercial software. Elastoplastic properties of materials as well as the filling process of subgrades in widened sections and critical placements of traffic loading were considered in the simulation. In particular, the non -uniform settlement behavior over newly-built and existing subgrades was assessed to explain premature damages of pavements commonly found in widened -road sections. Transfer functions were also used to predict the influence of widening subgrade sections on pavement responses. At the end, recommendations are made for design - construction based on results of numerical simulation.