High Fill Embankment Widening Project Of Differential Settlement Of Numerical Analysis

With the requirements of the tremendously increasing traffic flow in most areas in china, the existing 4-lane expressways can no longer meet the demand. It is very urgent to widen the existing expressways to 6-to-8-lane expressways. Widening of highway on soft ground may meet with the issues such as the interaction of the old and new embankments, the juncture of old and new abutment, differential settlement and pavement cracking along the joint between the old and new embankments. The interaction and differential settlement between the old and new embankments are researched with numerical method in this paper.In the paper based on the review of widening of highway, as to direct splice type of embankment widening, whether use small non-sand concrete pile, a comprehensive introduction is given to the problems of widening on the soft foundation such as the calculating methods, the soft foundation treatment design, linking measures of new and embankments, the controlling criteria about the settlement of new embankment and differential settlement of the new and old embankments. This thesis also studies and analyzes in detail how the main physical mechanics parameters of the foundation affect the settlement of new embankment and differential settlement of the new and old embankments. The finite element technique using a Drucker-Prager elastic-plastic soil behavior model are applied to the analysis of interaction mechanism between the old and new embankments in the widening of highway embankments on soft foundation soils. Conclusions are gained that the construction of new embankment induce differential settlement between the center and the shoulder of old embankment, then pavement cracking is come forth and the grade of highway is debased. Right treatment techniques should be taken to reduce the influence of the widening on the old embankment.Small non-sand concrete pile should be applied to soft soils in widening of highway. The finite element technique is applied to the analysis of the deformation features of embankments. Also the analysis of the deformation features is of embankments with the length of the pile and the compound mold measure of the compound foundation. The use of small non-sand concrete pile can clearly reduce the influence of the widening on the embankment. Pass the calculation and analysis enunciation, it shows that the calculation results obtained by the calculation model elaborated in this thesis can clearly reduce the settlement of new embankment and differential settlement of the new and old embankments. Obtain the result as follows:(1) The construction of new embankment induce differential settlement between the center and the shoulder of old embankment, then pavement cracking is come forth and the grade of highway is debased. Right treatment techniques should be taken to reduce the influence of the widening on the old embankment.(2) The weak soil layer model variety to the roadbed crest the noodles is the biggest to sink to decline quantity to sink to decline the quantity influence degree to compare and difference greatly, the soil layer model more big, the roadbed earth's surface of biggest sink to decline quantity more small, the horizontal difference sinks to decline quantity also more small.(3) Along with open widely the increment of the width, the center line position earth's surface sink to decline quantity to have already let up slightly, but the original roadbed is the biggest to sink to decline quantity to have aggrandizement.(4) Establish small non-sand concrete pile obvious to the control function that the new and old roadbed sinks to decline to transform, can let up an original embankment of biggest sink to decline quantity, lower a horizontal ascent ratio of the road watch.(5) Along with the increment of c, more obvious to the control function that the new and old roadbed sinks to decline to transform, when pierce through soft soil layer pierce through soft soil layer, can reduce to widen engineering consumedly a horizontal ascent to compare a change quantity to the old road, and can let up the level of the roadbed to move effectively, and biggest value the position have to let up.(6) The compound foundation model that passes the change processing district can't let up to sink to decline the quantity and side toward to move quantity availably.(7) The post-processing technology of thick filling on highway soft-foundation can accelerating solid knot of foundation to transform speed, shorten to sink to decline stable time and valid reduce work to expect to wait the technique advantage that the aspect all handles a technique first to have more.