Research On Expressway Maintenance Solutions In The Northwest Of China

The total mileage of expressway in China had reached 4.1×10~4km at the end of 2005 after 17 years' rapid development, which puts China in the second position in the world. The freeway network will reach 8.5×10~4km by 2020, approaching the USA in term of total mileage. The maintenance of motorway pavement is becoming more and more important in order to keep the performance of the road service in terms of safety, comfort, speed and economics.The construction of motorway in the Northwest was delayed in the past compared with other parts of China, as influenced by the geography, the economy, the culture and the society in the Northwest.With the conduction of the China"Western Development" strategy, the construction investment to expressway in the Northwest has increased year by year. The rapid development of freeway in this area has strongly promoted the national expressway network.This dissertation focuses on the maintenance of expressway in the Northwest of China. The expressway disease types, their causes, affecting factors, maintenance condition, traffic composition, local geography and climate were investigated on the spot. It is concluded that there are three kinds of typical illnesses of expressways, which are transverse cracking, potholes and rutting.The important problems in the construction and management of expressway were analyzed, including the relationship between climate and maintenance, traffic and maintenance, construction and maintenance, administration and maintenance.A pavement condition evaluation model is established for the expressway in Northwest area, taking the damage rates of transverse cracking, potholes and rutting as main considering factors. Based on the surveillance data, a maintenance cost model is set up. The cost model and the pavement condition evaluation model for expressway maintenance are combined to decide the maintenance priority level, which will offer the basis for rational allocation of maintenance investment, improving maintenance quality and lowering the maintenance cost.In this paper, the maintenance standard is put forward based on the three typical diseases of expressway in the Northwest China by referring to other area and abroad. A set of appropriate maintenance techniques is established. With this technical set and the maintenance standard, the method for selecting maintenance means is set up, providing basis for the rational decision in maintenance planning.Finally, with the analysis of current maintenance management of expressway, administration strategy is introduced to overcome the existing drawback. The strategy includes supervision, tendering and bidding, and equipment lending for improving expressway maintenance.