Study On The Characteristics Of Liquefied Soil Reinforced By Different Density Under Upper Load Based On The Shaking Table Test

Sand liquefaction reinforced is an important issue of Geotechnical Engineering. As the frequent occurrence of earthquakes and the soil liquefaction cause tremendous damage. Study on this part is particularly important. Gravel pile eliminate the soil liquefaction have been made lots of achievement on study. Composite pile reinforcement of liquefiable foundation have been used in actual engineering. However, research in gravel pile and steel pile composite reinforcement liquefiable sand soil which affected by density and upper load need do a lot of in-depth researches. Therefore, exploring the effects of density and upper load have some reality significance.This thesis is supported by National Natural Science Foundation of China(No.51408393)’Horizontal vibration mechanism of PHC pile in unsaturated soil under seismic wave’, mainly carrying out shaking table experiments of three soil liquefaction models reinforced by gravel piles and gravel-steel opposite angle composite piles and gravel-steel opposite composite piles under effect of different density and upper load. The density are 1.6 g·cmˉ3 and 1.7 g·cmˉ3. The upper load are 6kg and 9kg. We collect excess pore water pressure and earth pressure and earth acceleration to drawing curves and making analysis. Then we find :(1) In three kinds of reinforcement model, the pore water pressure curve drive are slowly increases to a peak with the vibration, and then gradually restore calm until the end, but the peak is different. The gravel piles model and gravel piles-steel pipe piles arranged diagonally reinforced composite models of the pore water pressure changes in the larger group, while the the pore water pressure of rubble pile and steel pipe pile composite reinforcement arranged opposite each model group are closely.(2) Acceleration changes of different reinforcement models show gravel piles model and composite piles model both reaches a maximum depth of 24 cm, while the opposite composite model arranged at minimum depth of 24 cm, that explain gravel pile the possibility of composite pile piles arranged diagonally cut off the middle of the model is large, anti-liquefaction ineffective here; composite pile pile is small compared to the overall acceleration opposite arrangement, pile normal functioning anti-liquefaction, anti-liquefaction better.(3) Earth Pressure of different reinforcement models show that the three models all reache a minimum at the depth of 24 cm. The earth pressure from small to large order of priority for the composite arranged diagonally model, model gravel pile, composite pile arranged opposite model which described three models in the middle of the pile varying degrees of liquefaction, pile central may lose varying degrees of resistance to liquefaction, in which the reinforcement effect of earth pressure composite pile is arranged opposite the largest model, compared to other modes strengthening anti-liquefaction better.To sum up, across gravel pile and steel pipe column complex arrangement reinforced soil liquefaction model is a better model of anti-liquefaction; central position reinforced soil liquefaction model pile is the weakest part of the force, three post-type central varying degrees of anti-lost liquefaction; density and greater impact on the upper load liquefaction. Therefore, the actual project can be considered gravel pile and steel pipe pile composite reinforced soil liquefaction opposite arrangement would achieve better reinforcing effect.