Manual Digging The Hole Belled Pile Vertical Bearing Capacity Calculation

Although man-made pile with bulb shaped base has now been used comprehensively, its calculation of bearing capacity has still no code to observe. Through a lot of test pile material , this essay concludes the vertical bearing capacity calculation formula of man-made pile with bulb shaped base by strength theory and relative deformation as control criterion .The method of defining pedestal pile foundation deformation modulus is especially discussed in this article, and it takes the Mindlin solution as the starting point using mathematics method to get the Poisson's ratio(u) which is the factor influencing foundation soil deformation modulus , and a deformation modulus calculating equation is finally determined. On this foundation the article inducts in detail the method which is based on the relative settlement of calculating unit area end support (qb) force at the same time considering the feature of pedestal pile's "arch effect" the article introduces conception of pile effective length and finally obtain the formula of calculating man-made pipe with bulb-shaped axial carrying capacity .The article uses MARC program to calculate and analyze foundation soil's stress and displacement and gets the change curve chart and the proportion that is shared by king-pipe side soil friction resistance and pipe end counterforce respectively .The article inducts the structure of pedestal in detail on the basis of generalizing pedestal application cases of many countries.