The Study And The Numerical Analysis Of The Bearing Capacity Of The Small Precast Pile Of Transmission Tower In Soft Soil

Small precast pile is a tiny pile and high strength prestressed concrete pipe pile(PHC pile) combined with product, which has the advantages of miniaturization, high strength, quick construction, Small precast pile foundation is suitable for transmission tower foundation of mechanical characteristics, meet the demand of bearing capacity and deformation, and can play a prefabricated pile construction fast advantages. At present, for small precast pile foundation design and calculation of pile foundation design still uses the general, did not consider the particularity of small precast pile, design an old-fashioned, play against small precast pile bearing capacity. In this article, through the indoor model test and numerical analysis, fully considering the interaction of high-rising transmission tower, study the effect of small precast pile bearing capacity and deformation law. Under wind load, the dynamic response of the pile foundation of the transmission tower small precast and bearing capacity characteristics. In this paper, the research will enhance the understanding of small precast pile for transmission towers’ force bearing characteristics, influence factor analysis, and parameter analysis will promote the improvement of the transmission tower of small precast pile design theory, and promote small precast pile’s application in transmission line.Through the indoor model test to study the bearing capacity and deformation of pile diameter, pile number for small precast pile. Study the load-bearing characteristics and deformation characteristics of prefabricated pile and its influencing factors, and using the model test’s results to verify the rationality of the numerical model as well.Using the verified numerical simulation to establish small precast pile-soil finite element model and have a further study of small precast pile’s load-bearing characteristics and then conduct a detailed analysis of the parameters. In this paper, we study the different parameters of pile, pile length, pile diameter, pile spacing, pile number) for small precast pile load-bearing characteristics and the influence of the deformation law and sensitivity analysis. The results show that the relative to pile length and pile diameter greater effects on the bearing capacity of single pile; Compared to pile spacing and pile number, pile spacing greater influence on the bearing capacity of pile group.According to the characteristics of the transmission line, established the transmission tower pile soil- wire- the three dimensional finite element model which considered their interaction, and using MATLAB to simulated the wind load time history curve as the input power load, and then analyze the dynamic response of wind load on small precast pile. And have a further study of the influence of different wind speed for small precast pile. The results show that:(1) Compared with the side pile and the center pile in pile group, Angle of pile undertake most of the horizontal loads, which is caused by stress concentration phenomenon of the tower foot;(2) The greater the wind speed, the greater the displacement, stress and displacement of pile top, which shows that the wind speed have obvious influence on small precast pile’s dynamic response.