Settlement characteristics of soft soil in the railway station

According to theoretical calculation and constrution monitoring of settlement,it shows that the soft soil has great settlement in the action of additional load,including filling which is the main reason of settlement,rail structure and train.Consolidation time of soft soil before treatment was so long that it would take 12 years to satisfy the demand of the post-construction settlement of subgrade which must be less than 20 cm.Consolidation time of the soil after treatment with plastic plate for drainage(vacuum preloading) became so short that it would take only 240 d to meet the demand of the settlement of subgrade after acceptance which still includes the settlement velocity being less than 5 cm/a.Due to the difference between the calculation hypothesis and practical construction condition and the complexity of the formation of soft soil,measured settlement value was not completely coincide with the calculated value.Measured settlement value was a little greater than the calculated value and the measured value would become stable in about 2 years that was longer than the calculated value.It shows that the greatest setterment position obtained by either calculation using finite element method or measurement lies in the central line of subgrade surface,and the settltment of verge takes second place.The least settlement is at the toe of the embankment slope.The conclusions can be regarded as reference to the similar soft soil in design and construction.