Research On Key Technology Of Construction By Stages For Freeway Pavement

There are many marine-deposition, lake-deposition and river-deposition areas in inland and southeast of China. Parts of freeway were constructed on the base of soft ground or poor ground. Although relevant methods were adopted to reinforce the ground in design and construction, the outcome was not as good as what people expected. Pavement construction by stages is a possible way to deal with these freeway drawbacks. But the pavement design & construction by stages is a complicated system engineering with many influential factors. In this paper, a systematic research on the freeway pavement construction by stages is carried out, based on the former works done by others, combining with the real projects, and main achievements are obtained as follows: 1. The conditions for use and basic principle of freeway pavement construction by stages are analyzed and summarized systematically, and the indexes for traffic volume conditions and geological conditions to determine if the pavement shall be constructed by stages are provided. 2. For soft ground or other poor ground, the factors influencing second-stage pavement paving time are analyzed, and the methods determining the service life during transition period are proposed according to settlement theory of soft ground. 3. Some key technical problems and measures of pavement construction by stages are proposed. 4. Based on the current pavement design specifications, design procedures and basic methods for bituminous pavement and cement concrete pavement construction by stages are put forward. 5. For the real project, the method of life cycle cost analysis is adopted, by means of reasonable economic influence modeling, considering pavement initial construction cost, maintenance cost, vehicle operating cost and pavement residual value, economic analysis is made for pavement construction by one-stage and stages, and detailed economic comparisons between the two schemes are made separately by the methods of present value and annual value. This research paper shows that, under certain conditions, pavement construction by stages is of outstanding advantages and remarkable economic value in fulfilling financial resources, reducing maintenance cost and improving pavement quality.