Test Of Vertical Bearing Capacity And Numerical Analysis Of Large-Diameter Artificial Excavated Belled Pile

With the rapid development of economic construction and engineering construction, more and more higher, bigger, heavier buildings have sprung up all over the world, it decides the load-carrying property of the foundation for higher requirement and greater challenge. In this environment the large-diameter belled pile has been more widely applied throughout every corner of the world.The large-diameter belled pile has advantages of large bearing capacity, small settlement deformation, high stability and no noise pollution, etc, and it has been widely used in domestic and abroad, but the theoretical research and design are still in its infancy, in aspects of the bearing capacity and deformation calculation have not been made unified fixed accessor methods. So far, scholars and experts in domestic and abroad has got many ways of determining the bearing capacity of the pile end through researches and analysis, the most accurate among which is the field static load test, but it has big workload and requires a lot of manpower and material resources, the test is difficult and the result is not easy to get.As to the above problems, this article did vertical static load test on three large-diameter artificial excavated belled piles of hebi stadium, and according to the condition on site, use the large finite element software ANSYS, chooss the appropriate boundary conditions、contact conditions and convergence criteria, establish the model of the belled pile-soil system, the calculated results are nearly identical to the test results through calculation and analysis, and it verifies the feasibility of the model.Based on the feasibility of the model, analyse the rule of settlement of pile and soil、the rule of vertical stress distribution of the pile and stress distribution law in the pile bottom, simulate and analyse the influence of the different belled diameters、the different belled heights and the different heights of the pile to the vertical bearing capacity. The results show that, when belled diameter D is largen, the vertical bearing capacity will be enlargement, the increase slows until the D/d is greater than2; when belled height h is largen, the vertical bearing capacity will be enlargement, and the increase amplitude is relatively flat, consider from several aspects, the optimum value range of h/D is0.5～0.7; When pile height H increases, the vertical bearing capacity increases significantly, as pile height increases to a certain extent, the side friction undertakes much of the load, and the belled losses its due effect, it leads to the increase of the vertical bearing capacity becomes very slow.