Research On The Regularly Of Dynamic Compaction For Reinforcing Loess Embankment

The dynamic compaction method has been widely applied in soft ground treatment in highway constructions , but there is no suitable theory its designing. furthermore, It is still a problems that how to make compacting loess embankment to satisfy the deformation, intensity and stability. Basing on the researches at home and abroad, aiming at the application of dynamic compaction in compacting loess embankment, The mechanism of dynamic compaction and the results of dynamic compaction caused by dynamic compaction are analyzed in this paper. The main work is as follow:1. The dynamic compaction parameters and the mechanism of dynamic compacting wet collapsible loess embankment were analyzed by the-on-the spot test of dynamic compacting loess embankment and backfilled loess soils, and obtained the practicalble parameters of dynamic compact of TONGHUANG highway engineering, by the way , comparing the results of finite element method whit the results of the test. at the same time, The criterion for determining the affected zone has been obtained. The developments of plastic zone in same impact energies but different number of drops had been obtained, which can be used to forecast the distribution rules of reinforced zone of dynamic compaction effectively.2. The improvement effect of dynamic compaction, aiming at collapsible loess and backfilled loess soils embankment, has been studied by ANSYS using geometric nonlinear three-dimensional finite element method. Several problems which are concerned in practical engineering has been studied, and the main conclusions could be summed up as follow:(a) That strongly-improvement deals with unsaturated loess embankment could be warranted dynamic compaction , besides it is suitable for dynamic compaction incidence to be compartmentalized by plastic deformation zone, calculating the amount of settlement according to numerical analysis is more accurate than according analytic theory.(b)Reinforced loess embankment is fit to be taken strong dynamic compaction.(c)The reinforcing effect is better for dynamic compacting the loess with a relatively little dry weightiness ratio, and that is a good measure to adjust the water content of the loess with a relatively little dry weightiness ratio when we reinforce embankment by dynamic compaction, on the other hand, dealing with the loess embankment with a relatively large dry weightiness ratio, its water content can be ignored.(d)Cohesive strength evidently affects the dynamic compaction effect to the loess with a relatively high water content, and the Internal friction angle markedly influence the effect of dynamic compaction for the loess with a invariable water content.