| In large-scale landslide control projects,support is the main control measure,and anti-slide pile is one of the most common support structures.Anti-slide pile has the advantages of simple structure,strong supporting ability,mature theory and high reliability.The section forms of anti-slide pile mainly include circular anti-slide pile and rectangular anti-slide pile.Under the condition of the same cross section area,the bending resistance of square pile is stronger.But the round pile is convenient for mechanization construction,construction speed is faster,the construction process is safer.For some emergency projects with landslide symptoms,rectangular pile construction speed is slow and the risk is high,while round pile construction is convenient and safe,but the bearing efficiency is low.In this context,the new type of anti-slide retaining structure,the figure 8 anti-slide pile,arises at the historic moment.It is made of mechanical holes,and under the same cross section area,it can resist greater landslide thrust,and has a great application potential by combining the advantages of round pile and rectangular pile.In this paper,numerical simulation and theoretical research are combined to study the stress distribution,displacement and carrying capacity of the figure-8 anti-slide pile,and compare it with the round pile and rectangular pile,etc.The main content of the research and related conclusions are as follows:(1)By looking up relevant literature and books,the main forms of anti-slide piles at the present stage and how ABAQUS simulates reinforced concrete materials are understood,and the modeling of fig-8 anti-slide piles studied in this paper and the selection of relevant parameters are described.(2)The ABAQUS numerical simulation software is used to simulate the rectangular pile,and the stress distribution form,the evolution process of displacement with load and its bearing capacity are analyzed.It is proved that it is feasible and reasonable to simulate the anti-slide pile through the ABAQUS software.(3)It is found that the ultimate displacement of rectangular section anti-slide pile decreases with the increase of section size,brittleness increases,ductility decreases,that is,the ultimate bearing capacity and deformation capacity are negatively correlated.Its failure mode is mainly shear compression failure,and the failure location is 0.35 L ~0.40 L from the pile bottom(L is the pile length).(4)By introducing the theoretical formula of flexural efficiency coefficient,the flexural efficiency coefficient is used to evaluate the flexural performance of antisliding pile.Through the comparison of flexural efficiency coefficient,it is found that the theoretical flexural performance of figure-8 anti-slide pile is better than that of round pile and square pile,but slightly lower than that of rectangular pile(length-width ratio is 2∶1),and the optimal distance from center of circle of figure-8 anti-slide pile is 0.8d.(5)The ABAQUS software is used to model and calculate round piles,rectangular piles and figure-8 anti-slide piles,and analyze their stress distribution,displacement,bearing capacity,etc.The results show that,under the same cross-sectional area,the figure-8 anti-slide pile has smaller displacement and better bearing capacity than the round pile.Under the condition of the same cross-sectional area,the ultimate bearing capacity of the figure-8 anti-slide pile is lower than that of the rectangular anti-slide pile(the ratio of height to width is 1.4:1),which is about 14% lower than that of the rectangular anti-slide pile(the ratio of height to width is 1.4:1).(6)The results show that the change of center distance L has a great influence on the ultimate bearing capacity of the figure-8 anti-slide pile.The ultimate bearing capacity of the figure-8 anti-slide pile(center distance L=0.8d)is about 16.7% higher than that of the figure-8 anti-slide pile(center distance L=0.5d).Under the condition of the same reinforcement ratio,with the increase of center distance L,figure 8characteristics of anti-slide pile has a transfer from proper muscle damage to the trend of super muscle damage,but reduce the reinforcement ratio can better improve the vicious trend,that is,to maintain proper muscle damage features,under the condition of center distance L and reinforcement ratio within a certain range is negative correlation between rho. |
