Study On The Soft Soil Settlement Under The Conditions Of Change The Consolidation Coefficient By Numerical Simulation Analysis

Consolidation settlement of soft soil deformation mechanism is very complex, and influenced bymany factors. Therefore, the consolidation settlement control of soft soil of highway construction has beenan important research subject. In this paper, up to the high embankment of Da Yu Expressway, combiningtheoretical analysis, laboratory experiments and numerical simulation analysis to research the consolidationsettlement of soft soil, the main work are as follows:First, for a routine physical indicators test of soft soil, consolidation compression test and thepenetration test, the test results show that: the soft soil permeability and void ratio decreases exponentially.Consolidation coefficient was calculated by secant modulus method, the results show that: consolidationcoefficient decreased firstly, then increased variation.Second, the simulation of the settlement of soft ground under the condition of untreated was calculatedby FLAC-3D, the simulation results show that: the time of the settlement of soft ground is about1000days,the final settlement of the centers is40.22cm, the excess pore water pressure in reach maximum when thefilling is finished, the excess pore water pressure of the road at1m depth is73.47kPa. The simulation ofthe settlement of soft ground under the condition of treated by PVD was calculated by FLAC-3D, thesimulation results show that: the time of the settlement of soft ground is about240days, the final settlementof the centers is41.11cm, the excess pore water pressure in reach maximum when the filling is finished, theexcess pore water pressure of the road at1m depth is34.4kPa.Finally, the simulation results with field test results were analyzed. The results showed that: at thesame time, the final settlement of field test is36.55cm, the final settlement of simulation of treated by PVDis39.23cm, the difference between the two is only2.68cm. The trend of excess pore water pressuredissipation of field test and simulation is same; the time of the settlement of soft ground which treated byPVD is about240days,untreated is about1000days, the PVD make time of the soft soil settlementcompleted reduce about4times.