Study On Bearing Capacity And Calculation Method Of Laterally Loaded Piles Under Slope Conditions

China has a large number of local governments and a large number of mountains and rivers.In recent years,with the increasing demand for infrastructures such as railways and highways,many roads are inevitably straddling complex terrain such as rivers and slopes.Because of its high bearing capacity and good stability,it has become the first choice for basic forms.Compared with the laterally loaded piles on the flat ground,the pile foundations in the slope segment have certain particularities in the stress environment,use function and geographical position,which results in the lateral load-bearing piles in the slope segments.Then use the design calculation method of the ground pile foundation.In view of the above problems,this paper intends to conduct in-depth research on the load-bearing characteristics of laterally loaded piles in slope segments using indoor model tests and finite element analysis.The specific research work is as follows:(1)The current research status of laterally loaded piles in slope segments is briefly introduced,and the difference in lateral bearing capacity between piles and plain piles is analyzed,and the calculation theory for the bearing capacity of single piles under horizontal loads is performed.to sum up.(2)The indoor model tests are carried out for two conditions of ground pile foundation and slope pile foundation,the test is divided into two groups.In the first group,lateral load-bearing piles located at the midpoint of the ground,30°,45°and60°ramps are set respectively,the second group is provided with lateral load-bearing piles located at different positions on the 30°ramps respectively and obtain the pile foundation load and displacement curve,pile bending moment curve.Through the analysis of the test results,it can be concluded that the presence of the slope weakens the lateral bearing capacity of the pile foundation,and the greater of the slope,the more weakened the lateral bearing capacity of the pile foundation;the different position of the pile foundation on the slope will have different lateral bearing capacity,when the pile foundation moves from the slope foot to the midpoint of the slope,the lateral bearing capacity of the pile foundation will continue to weaken,When the pile foundation moves from the midpoint of the slope to the top of the slope,the lateral bearing capacity of the pile foundation will continues to increase.(3)In order to study the effect of the elastic modulus of pile diameter,pile lengthand soil on the bearing properties of pile foundation,a numerical model was established in this paper using ABAQUS.The analysis results show that the increase of pile length can improve the lateral bearing capacity of the pile foundation.However,when the pile length reaches a certain length,the significance of increasing the pile length is not significant,and it will cause waste.The increase in the pile diameter can improve the pile foundation.The lateral bearing performance,but for economic reasons should be reasonable to determine the pile diameter,increase the elastic modulus of the soil can also significantly improve the lateral bearing capacity of the pile.(4)The results of the indoor model test were further analyzed and the py curve of the pile foundation was obtained.The analysis results show that the hyperbolic p-y curve expression on the flat ground is no longer applicable to the slope pile foundation,accordingly,the double The critical soil resistance parameters Np and initial stiffness ki of the two key parameters of the curve-type py curve are reasonably modified.The expressions suitable for calculating the Np and ki values of the pile foundation of the slope are obtained,and the pile foundation suitable for the slope is obtained.The py curve,compared with the experimental results of this paper and others’ experimental results,shows the rationality of this method.