The Theory And Engineering Application Of Mixing Pile Combined With Geogrids Reinforced Bridge Abutment Soft Foundation

With the further development of China’s highway construction, more and morerisks have threaten the operational highway. And the bridge jumping is one of the mostcommon problem that existed in the highway construction, which have seriouslyinfluence the driving comfort, and decreased the driving speed and road capacity of thevehicle. Huang e freeway exists in soft soil area, in order to ensure the safety ofhighway in the operation of normal use. The need for soft soil section, especially thesoft subgrade bridge and culvert platform back for special treatment. On the basis of asummarized research about the jumping control techniques of the bridgehead,the thesishave given the applicability of the bridge-head handling methods, and hope to providecertain theories for the bridge-head under different geology conditions. At the same time,relying on the soft foundation methods of comprehensive disposal technology treatmentof bridge transition section of the DJM pile and geogrid in practical engineering.According to the construction of the tight schedule, the properties of soil have verygood effect. The analysis of differences between the road and bridge connection sectionof the settlement mechanism and stress characteristics of pile net. To treat softfoundation at bridge head, prevent bump has certain guiding significance in disease.First of all, the thesis analyzes the reason and the principle of the differentsettlement of the bridge and embankment approach, then make a summarize about thecontrolling measures, such as foundation treatment technology, the excavation fillinglean concrete, pre cast high treatment method, treatment units back fill, surfacetreatment of geogrid, drainage consolidation method and comprehensive treatmenttechnology,to handle the problem.Secondly, Based on soil arching to analysis of the stress mechanism of the pile andthe reinforcement pile. And make a compare between the Hewlett model test and thetest results, the result proved that the method that this thesis put forward is reasonable.Thirdly, the thesis introduces a different settlement control technology about thebridge and embankment approach, which is called dry jet mixing pile combined withgeogrids technology. This method used U-steel or U-nail to firm the geosynthetics andthe reinforced concrete structures, Its unique structural characteristics can decrease thelateral displacement and the differential settlement between the bridge and embankment,this technology can also enhance the global stability of the embankment and increasethe pile bearing ratio.Lastly, through a field test which was carried out on a bridge-head soft foundationthat was handle by dry jet mixing pile combined with geogrids to research the reinforced effect, and make a compare such as settlement, displacement and soilpressure between reinforcement and non-reinforcement embankment. The results showsthat the dry jet mixing pile combined with geogrids foundation can effectively reducethe settlement and different settlement.