| In the cold winter, snow and ice of the road is greatly harmful for dynamic property and safety of traffic driving, which seriously affects traffic capacity, brings inconvenient to passenger transportation and causes huge economic losses; moreover, traffic accident in snow and ice season increases multiply, which critically threats the drivers'and passengers' properties and life safety. At present, there are many clearance methods for road surface at home and broad, but they have different degree harm. For example, artificially mechanical removal method would obstruct traffic and impact capacity; deicing salts have some defects including environmental pollution, structure corrosion and freeze-thaw; conductive concrete is complicated on craft and expensive; heating cables would cause injure to material using performance and pavement structure performance because of its high temperature stress and energy consumption. Therefore, it is practically significant to adopt new Snowmelt deicing clearance method with less harm for road surface, especially highways, airport, ramps, tunnel ramp and other special section.Aimed at the research status of melting ice, this topic takes the sub-project that is removal ice, anti-sliding and multi-function tunnel asphalt pavement, from the national "863"hign-tech project that is《The Composition, Function and Design procedures of Multifunctional tunnel》(Serial number:2006AA11Z117), as the research content. According to the requirement of tunnel entrance ramp to high anti-freeze sliding resistance performance of asphalt pavement, pavement material system of asphalt concrete is mainly produced, and according to snowmelt level and construction requirements, paving way is preliminary determined.Based on the previous work, this thesis studies the force condition after Phase Change asphalt Concrete Pavement by Heating System. Through the finite element model of structure analysis, the deflection value and maximum shear stress law of asphalt Concrete Pavement by Heating System of Phase Change under different loading, are particularly studied. The aim is to prove the safety of asphalt Concrete Pavement structure by heating system of phase change through mechanical analysis. Research shows that, pavement parameter (including lay forms,buried depth,heat power) is reasonable. Meanwhile, the other factors to pavement parameter are discussed in detail.The main content of this thesis as follows:(1) Based on the finite element theory, applying the ANSYS software, the finite element model of the real pavement structure parameters is established. Furthermore, in many working conditions, phase change snowmelt deicing of asphalt concrete pavement structure is conducted stress analysis.(2) Phase change fever snowmelt deicing of asphalt concrete pavement is that Phase change fever will be lying on of asphalt concrete pavement. According to the design of asphalt concrete can be JTGD rules "(50-2004) requirements, calculating index under different load simplified model of pavement structure is analyzed.(3) Under vertical load, the mechanical response of phase change asphalt concrete pavement with Heating System is analyzed. Under different wheel load, different grounding area and different load distribution, the law of deflection value, maximum shear stress and shear stress curve on fever system surface of phase change asphalt concrete pavement structure with heating system are studied.(4) Under lateral load, the mechanical state of asphalt concrete pavement with phase change heating system is discussed under different vehicle loading position, different road friction coefficient conditions.(5) The action mechanism of the other larger factors on aid parameters of phase change system is explored. The modulus of elasticity of pavement structure surface material and heating power of phase change heating system have considerably impact on reasonable ascertaining laid parameters.Research shows, the finite element model of asphalt concrete pavement with phase change heating system for snowmelt deicing is reasonable and feasible. According to the maximum deflection value, maximum shear stress by model calculating satisfying the requirement of asphalt concrete design rules, the previous certainty laid parameters with phase change system is feasible. |
PDF Full Text Request