Bump Disease Control Study

Abutment bump is generated by the non-uniform settlement between structure and embankment of behind abutment, and it's one of the eight main common faults of freeways. How to alleviate or eliminate abutment bump has been a desiderate problem to be settled in freeway construction.Combined with the treatment to behind abutment in WEI-JIAO freeway project and based on a large amount of reference to literatures and data at home and abroad, this paper analyses and researches the causes of the disease of abutment bump and its mechanism. Based on the energy conservation principle, it sets up a reasonable mechanical model of transition sections at bridgehead and derives the calculating formula of driving and load of transition sections at bridgehead. It also classifies the manifestations of non-uniform settlement, analyses and researches the control to non-uniform settlement theoretically. On this base, this paper puts forward the controlling standard of non-uniform settlement on the principles of comfort and security. At the same time, it analyses the structure of setting bridgehead plate, analyses and calculates the setting bridgehead plate of transition sections at bridgehead by using the theory of elastic foundation, thus the reinforcement calculation and method of setting bridgehead plate are obtained.Based on the above analysis and calculation and combined with the conventional treatment methods to abutment bump at home and abroad, this paper researches integrated control techniques to abutment bump at the aspects of foundation treatment embankment and pavement treatment of behind abutment and drainage measures,etc. and puts forward the foundation treatment measures such as replacement method, heavily ramming method and lime-fly ash mixed gravel pile method. The treatment measures to embankment of bridge behind abutment such as geogrid method, heavily ramming method and lime- fly ash mixture replacement method are also presented. And the treatment measures to pavement of behind abutment such as setting bridgehead butt plate and use of transitional pavement are put forward. The improving measures to drainage of behind abutment are presented.