Analysis Of Bearing Characteristics Of Magnesium Oxide Carbonized Piles

In this paper,soft clay in a certain area of Hefei City was selected as the treatment object,and the magnesium oxide and carbon dioxide were used as curing agents,and the pile samples were used for carbonization and reinforcement.Through the indoor model test,the bearing characteristics of single pile under different environments are studied separately: First,buried the pile in the soil,by measuring the settlement data of the single pile top and the pile body strain data,the bearing deformation characteristics of the pile under vertical load are analyzed;the second is to study the single-pile sample,through the stress-time relationship curve and the pile body strain data,the bearing deformation characteristics of the single-pile sample under horizontal load are analyzed.Based on the model test,finite element analysis software MIDAS GTS is used to analyze the bearing characteristics of single piles subjected to vertical and horizontal loads in soil.In this paper,the combination of indoor model test and MIDAS GTS finite element analysis is used to compare and analyze three different pile types of round pile,square pile and pipe pile.At the same time,the bearing performance of ordinary piles and carbonized piles is also compared and analyzed to verify the bearing performance advantages of carbonized piles.The main research contents and conclusions are as follows:(1)Through the indoor model test,test the bearing performance of the pile in the soft soil when the pile is subjected to the vertical load,and obtain the load-settlement curve of the ordinary and carbonized round pile and square pile,and the axial force distribution of the pile body,and the distribution of friction on the pile side.The load-settlement curves of the four piles all show a slow-changing growth,and the axial forces of the piles are gradually decreasing along the depth direction,and the lateral frictional resistance of the piles is also better.The difference is that the carbonized piles are better than the ordinary piles and the square pile are also better than the round pile,it is manifested that the pile top settlement is small,the axial force change amplitude is increased later,and the pile side friction resistance plays a greater role.Finally,it is concluded that the carbonized pile has higher strength than the ordinary pile,and the square pile has a relatively higher bearing capacity than the round pile.(2)Through the indoor model test,the horizontal bearing capacity of four single pile specimens is tested,and the horizontal ultimate bearing capacity and strain-time relationship of the single pile specimens are obtained.The excitation effect of the active magnesium oxide carbonized pile is significantly better than that of the ordinary cement pile.The main performance is that the post-carbonized pile has a horizontal ultimate bearing capacity of about 40% higher than that of the ordinary cement pile;whether it is an ordinary pile or a carbonized pile,the bearing capacity of the square pile can reach 2-3 times that of the round pile.The strain-time curves of the four single-pile specimens are basically the same,showing good deformation performance.The strain of the ordinary piles in the compression and tension regions has a tendency of brittle failure.The strain of the carbonized piles with time increase and increase,the crack develops steadily,and there is no tendency of brittle failure.(3)Using MIDAS GTS numerical simulation to analyze the performance of the pile subjected to vertical load in the soil.Through the different parameter settings of each pile,and extract the simulation data,and obtain the settlement deformation cloud diagram,load-settlement curve and pile of ordinary and carbonized round pile,square pile and pipe pile.The axial force distribution curve and the pile end res istance curve.Through comparative analysis,it is concluded that the square pile and the pipe pile have higher bearing capacity than the round pile,which is consistent with the indoor model test conclusion.(4)Using MIDAS GTS finite element analysis software,the effects of different pile diameters,different bearing layer stiffnesses and different pipe pile wall thicknesses on the vertical bearing behavior of carbonized single piles are discussed.From the load settlement curve,the larger the pile diameter is to promote the bearing capacity of the carbonized round single pile foundation;the greater the bearing layer stiffness,the higher the bearing capacity of the carbonized single pile foundation;within the bearing capacity range,as the thickness o f the pipe wall is thickened,the bearing capacity of the carbonized pipe single pile is lower.(5)Using MIDAS GTS numerical simulation to analyze the performance of the pile subjected to horizontal load in the soil.Through the different parameter settings of each pile,and extract the simulation data,and the horizontal displacement cloud map,load-horizontal displacement curve and pile bending moment distribution curve of ordinary and carbonized round piles,square piles and pipe piles are obtained.Through comparative analysis,it can be concluded that the square pile and the pipe pile have higher horizontal bearing capacity than the round pile.