Study On Lateral Displacement Characteristics Of Deep Soft Soil And Its Influence On Pile Under Loading

In recent years,the problem of pile foundation failure due to the vertical loading has become increasingly prominent in the depth and soft soil zone.In this paper,the deformation behavior of deep soft soils under loading,and the deformation characteristics of double-row passive piles are studied by the field prototype test of Ke Men harbor and FLAC3D.At last,the influences of different treatment measures on the lateral deformation to decrease direction displacement of railroad bed were studied,which can provide value of theroy and engineering application The main contents and results are as follows:The test has testified that the lateral displacement of deep soft soil has obvious spatial effect under the load.The lateral displacement value of the soft soil increases exponentially with the load distance.At the same time,the filling direction has a significant influence on soft soil lateral displacement,engineering fill should deviate from structures.When the width of heap carrier exceeds the limit value,the continued increase of width has little effect on the lateral displacement of soil.The lateral displacement was composed of instantaneous deformation and lateral extrusion which occurred in stage of consolidation,the result of the field test has proved that lateral displacement value in the stage of consolidation was 33.5 percent of total lateral displacement,hence,the horizontal displacement should be monitored strictly after loading.The width of load and distance did not have obviously effect on depth of shear slip plane,while the depth of shear slip plane would increase a little when the load increased.Because the hard shell would have a built-in function for the side inclined tube,leading a result that measured value was smaller than the real displacement of soft soil,when using it to monitor the lateral displacement.This paper discussed the value of correction coefficient based on the date of test.The failure to predict would be conducted,using side inclined tube to monitor the lateral displacement,and the date of the test has proved that the side inclined tube of PVC did not reach the limit value of deformation,the way of failure for the side inclined tube is broken.The prototype test and numerical calculation has testified that the former pile has shielding effect on the latter pile,the displacement and bending moment were smaller than the former.When the cross-sectional area of pile was increasing,which could have an influence to decrease the displacement of pile,while increasing the cross-sectional area has no obvious effect on decreasing the displacement of pile.The single isolated piles did not work effectively to deal with the displacement of the deep soft soil,but the double-row isolated pile would decrease the displacement of the subgrade obviously.In the procession of strengthening soft soil foundation to control direction displacement,increasing the reinforcement depth would play important role than increasing the reinforcement width.In the reinforced area of smaller replacement rate,the displacement value on the top of subgrade would decrease significantly,however,the displacement value was steady,when the ratio of mixed pile increased certain degree.hence,there would be a not economic result,if increasing replacement rate blindly.