| China is one of the countries with the largest area of land desertification in the world,accounting for 17.6% of the land area.With the strategic shift of economic construction focus to the west,more desert railways will be built.The prevention and control of railway sand damage is a long-term and arduous task.At present,high vertical sand barrier is a common engineering prevention measure for sand damage control.In the past,concrete cylinder foundation and wooden pile foundation were used for windproof sand barrier.Concrete cylinder foundation is easy to fall down,and cutting wooden pile damages the environment.Helical pile steel tube pile foundation has the advantages of low carbon environmental protection,convenient construction,good durability and so on.It is a good substitute for the former two,and is worth studying and applying.In this paper,the horizontal bearing capacity of helical steel pipe pile which can be used in high vertical sand barrier is studied.In this paper,on the basis of predecessors’ research,designed a set of uniform the circular pile/helical pile horizontal load test device,in sandy soil foundation level by the Dutch in the uniform circular pile and the co MParison of screw pile model test of pile top load-displacement curve,according to its,leaf,leaf bending moment of pile,pile side soil pressure distribution,etc.Through co MParative analysis of test results,the ultimate bearing capacity of circular and helical piles with different diameters under horizontal load and the influence of increasing pile diameter and helix on pile bearing capacity are discussed.Based on the model test,l-pile theoretical settlement and nonlinear finite element software ABAQUS are used to study the bearing capacity of circular piles and helical piles with different outer diameters under horizontal load.The results are consistent with the test values.Therefore,the modeling calculation of wind-proof sand barrier foundation by USING ABAQUS in a desert area is reliable.By analyzing its displacement and bending moment,the final design scheme is determined.The results show that the deformation of the three piles is rigid rotation,the rotation point is located at a certain depth above the pile bottom and the pile bottom is not fixed constraint,which belongs to the non-bending moment constraint.Co MPared with increasing the pile diameter,increasing the helix is more beneficial to improve the bearing capacity of the pile under large load.Based on the bending moment data,the stress of pile and helix under different loads is analyzed.The reasonable position of helix is the maximum bending moment of pile.By analyzing the P-Y curves of each soil layer of pile obtained from the experimental data processing,it is found that the homogeneous sand layer in the test is a two-section distribution of "parabola + straight line".The normal P-Y curve of helical pile is deviated due to the influence of helix. |
