Laboratory Model Test On Interface Strength Characteristics Of Soft Clay Foundation Treated With Drainage Piles

With the deepening of the concept of interdependence between engineering construction and geological environment,traditional pine piles as an natural material have shown advantages in environmentally friendly and reversible reinforcement.At present,in the application of soft soil foundation treatment,the pine piles only consider the displacement to form a composite foundation,and the bearing capacity is low,and the postconstruction deformation is large,which limits its application in engineering.Aiming at the advantages and disadvantages of traditional pine piles,the research team developed a new type of pine piles,namely drainage pine piles,which combines drainage consolidation and displacement,which is better for pine piles.The soft soil foundation has been explored.Drainage pine piles are used to treat soft soil foundations.The main mechanism lies in the replacement,reinforcement and drainage consolidation of drainage pine piles.This research is based on the preliminary research of the research group(Xiong Yifan,2016)that the drainage layer has a certain drainage effect,and further discusses the drainage pine pile technology.The shortcomings of previous experiments are that(1)the model size is ?100mm*H150mm.Because the vertical and radial drainage paths are close,the contribution of radial drainage consolidation to total consolidation is not clear under the same conditions.The reason for the analysis is that the model size is too small.(2)No study was made on the consolidation strength and the interface strength as a function of the consolidation degree.Based on this,the author tries to quantitatively evaluate the influence of the radial drainage of the drainage pine pile on the total consolidation degree and the research on the mechanism of the interface drainage and shear strength growth during the drainage consolidation of the drainage pine pile.The main contents of the research are as follows:(1)Improve the test model based on the research of the previous research group and determine the model size as ?100mm*H300mm;(2)Test basic soil physical and mechanical properties;(3)Study the effect of interface drainage conditions on consolidation strength under the same rod diameter and drainage layer conditions;(4)Study the influence of the change of the rod diameter and drainage layer on the consolidation strength of the drainage pine pole under pure radial drainage conditions;(5)Study the influence of the change of rod diameter and drainage layer on the pullout resistance of the drainage pine rod under pure radial drainage conditions;(6)To study the undrained shear strength of the soft soil cross-slab after the drainage and consolidation of the columnar soil layers in different schemes,and compare the results with the ultimate pull-out test results;(7)Preliminary discussion on the relationship between permeability coefficient and void ratio of soft soil in pure vertical drainage;The test results show that the radial drainage dominates the drainage pine poles under the same diameter and the same drainage layer but different drainage conditions;when the rod diameter is the same,the consolidation strength and interface strength increase with the increase of the drainage layer;The rod diameter and the drainage pine rod of the same drainage layer have a linear relationship with the shear strength of the cross plate under the corresponding state;the increase of the drainage layer and the rod diameter makes the soft soil layer treated by the drainage pine rod The undrained shear strength increases and the foundation strength increases.The friction between the drainage pine pile soil and the interlocking bite makes the relative displacement of the reinforced soil relatively flat compared to the pure pine pile.It is expected that the drainage pine pile technology can be It has a certain application prospect in the application of soft soil foundation reinforcement for small and medium-sized hydraulic structures and the treatment of sliding soil damage in underground soil sites.It is verified that the permeability coefficient and pore ratio of soft soil column model test in pure vertical consolidation drainage are Linear relationship...