Study On Reinforcement Mechanics And Consolidation Settlement Analysis Of Solf Foundation Treatment With The Method Of Prefabrieated Drain With Preloding

The soft soil is widely distributed in our country, It has poor engineering properties such as high water content, high porosity ratio, low strength etc. There are many unfavorable engineering characteristics for soft soil foundation, such as low bearing capacity, high settlement and long consolidation time. At present, there are many kinds of soft soil foundation reinforcement methods, the method of plastic drain with pre-loading to the treatment of soft soil foundation are more widely used, prefabrieated prain with preloding method is developed from sand drain preloading method, it have many advantages and get better benefits in engineering. As the method widely used, With the constant using it is studied also deepened ceaselessly,the research of the reinforcement mechanism, construction technology, design the mechanism is not in-depth,So the study of this method has a very important significanceBased on the previous work, through the local testing, theoretic study, numerical value simulation ect ways, to do the mainly following aspects of works:1. Several commonly prediction models and the calculation methods of soft foundation settlement were given out, the mechanism of prefabrieated drain with preloading is analyzed.2.Based on a large number of monitoring data, comprehensive analysis of soft ground settlement. Settlement is predicted by the hyperbolic method. Combined with the the measured data, the projection results and the calculation results, degree of consolidation calculation method of soft foundation after dredged sands is discussed, Results show that the degree of consolidation of soft ground can be up to80%～90%, and only20～40mm post-construction settlement shall meet the design requirements.3. Combined with the degree of consolidation of soft foundation in different periods and post-construction settlement, reinforcement effect of soft foundation treatment with the method of prefabrieated drain with preloading of is evaluated.4. Combined with the geological investigation report and the degree of consolidation theory calculation method, the influence factors of soft foundation reinforcement effect are analyzed,such as the well resistance, smear effect, spacing of prefabrieated drain, specifications of prefabrieated drain,result show that when the longitudinal flow capacity of prefabrieated drain is bigger than the horizontal permeability coefficient of Natural soil, And the length is relatively short, Well resistance effect can be neglected, Greatly influenced by smear effect, the "thin and dense" scheme is adopt to Engineering, Layout spacing in between0.8-1.3m is more appropriate.5. Combined with practical engineering,through the simplified method of sand drains and the establishment of sand drains three-dimensional solid element,this paper uses FLAC3D software tocalculate the three-dimensional consolidation of the experimental area.