Research On Reasonable Plate Spacing And Pile Spacing Of Disk Pile Foundation In Different Soils

Disk pile is a new type of reinforced concrete pile that is developed on the basis of common concrete filling pile. The bold innovation has been made on the body structure of disk pile. Compared with ordinary concrete pile, disk pile has high bearing capacity, small settlement deformation, strong adaptability, convenient construction operation and good economic gain and so on.The disk pile has been applied in many practical engineerings in our country and has achieved good effect. However, the stress mechanis m of disk pile is relatively complex, and its theoretical research is not yet mature and is lagging behind the engineering needs. Based on researches of experts and scholars at home and abroad, the present study, through indoor model tests and the numerical analysis of the finite element software ABAQUS, explored and analyzed deeply the reasonable plate spacing and pile spacing of disk files in different soils. The main research contents are as follows:(1)This research designed four groups of indoor model tests with model piles in the sand. Through data processing and comparison analysis, the results show that with the increase of plate spacing, the bearing capacity of double disk pile increases in varying degrees, but not linearly; difference of plate spacing has direct link with the bearing capacity of plate body; the effect of plate body in up and down place has obvious time effect; the reasonable plate spacing of single disk pile in soil is3D (D is the disk diameter).(2) Through four groups single disk pile tests with different plate spacing in silt, it is found that the reasonable plate spacing of single disk pile in silt is2.5D, which is different from that in sand. Thus, it can be concluded that the properties of pile soil will affect the reasonable spacing of two plates of single disk pile.(3)Through indoor model tests, the research analyzed the influence of different pile spacing of disk pile group on the bearing capacity. The results show that with the increase of pile spacing, the disk pile group effect gradually decreases and its bearing capacity increases. When the pile spacing reaches to certain spacing, the influence of the pile group can be neglected; the bearing capacity of pile group is the added value of the bearing capacity of single pile, but the pile spacing in different soils varies. According to the experiment results, the reasonable pile spacing of disk pile group is3D and2.5D respectively.(4)Using the finite element software ABACQUS to establish three-dimensional finite element calculation model of different plate spacing of single disk pile and different plate spacing of disk pile group, Numerical simulation was performed under different soil conditions. Based on the fact that the numerical simulation results are similar with the ones of the indoor model tests. Through a number of the finite element numerical simulation about different plate number of single pile and different plate spacing of disk pile group, other possible factors that affect the reasonable plate spacing of disk piles and file spacing of the pile group have been analyzed and discussed.