The Treatment Research On Soft Clay Ground Of Lanyong Highway Bridge Abutment Transition Section

In recent years, there is large-scale construction of highway in China, our country put road infrastructure as a top priority, more and more highway routes have to pass soil foundations of poor conditions.The bridge jumping problems connecting roads and bridges and culverts structures segment is particularly prominent, the bridge jumping problem not only affects the normal operation of the road, but also pose a threat to the safety of passengers.This paper combined with the Lan Yong highway soft subgrade technology research projects, first for the soft subgrade high water content, compressibility, low strength, poor permeability characteristics, elaborated the theory of soft soil consolidation, and settlement of soft soil calculation methods are briefly introduced.Secondly, through a detailed analysis of the reasons for the bridge jumping, bridging segment results is a fundamental factor in the differential settlement problems arising jumping. Then comprehensive study of the mechanism of the different treatment of soft foundation treatment measures, describes the applicable conditions of different methods and the advantages and disadvantages of those treatment method.Then, using nonlinear finite element software ADINA, build three-dimensional solid model that combines Biot consolidation theory, take the choice of the ideal elastic-plastic model of Mohr-coulomb to do the consolidation, use numerical simulation analysis the CFG pile composite foundation treatment of soft subgrade settlement. Analysis the surface settlement influence of the embankment and foundation in different design parameters such as different length, different pile spacing, different pile diameter, different cushion modulus, modulus of pile.Finally, through design the typical weak foundation of transition cross section K28+512of Lan Yong highway. For the geological characteristics of the segment, select CFG pile composite foundation treatment methods, by determining the scope of the transition section processing, checking CFG pile bearing capacity, analysis the variation of the surface of the roadbed,foundation, and pile settlement loaded with filling, the settlement variation of soft non-reinforced base surface, the pore water pressure in the soil consolidation process dissipate case, the horizontal displacement of composite foundation, the pile and soil vertical stress, and pile-soil stress ratio relationship changes over time. All in all, after using CFG pile composite foundation treatment of soft soil roadbed, significantly reduced post-construction settlement,meet the post construction settlement requirements of highway, can effectively solve the problem of bridge jumping.