Analysis Of Failure Mechanism And Ultimate Bearing Capacity Of The Single Framed Bent Supports Of Beam Aqueduct

Aqueduct is an important water conveyance structure and its safe operation directly affect the life and property security of people along the project. Furthermore, the bracing structure plays a vital role in bearing and transferring load, which closely correlates to the Aqueduct’s safe operation, thus it’s necessary to study the failure mechanism and ultimate bearing capacity of the bracing structure of aqueduct. This paper carries out the research on the failure mechanism and ultimate bearing capacity of the single frame bracing structure of beam aqueduct based on model test and numerical simulation method, and the main research work in this paper are as follows.(1)The Scheme of the model experiment is designed by using the single frame bracing structure of beam aqueduct in Guangxi Letan reservoir as the prototype. The rules of the failure mechanism and the ultimate bearing capacity of the structure is discovered through the experiment. The condition controlled by the vertical gravity load and the condition controlled by the horizontal wind load are considered according to the engineering practice. The two single frame bracing structure models are implemented with a 1:3 similarity ratio to the prototype. The three channel digital electrohydraulic servo harmony loading system is used to load by the step of 10% prediction of ultimate bearing capacity load before 80% prediction of ultimate bearing capacity load and 5% prediction of ultimate bearing capacity load after 80% prediction of ultimate bearing capacity load.(2)The applicability of the ANSYS reinforced concrete nonlinear analysis on the research of the failure mechanism and the ultimate bearing capacity is comparative studied based on the results of the model test and it provides scientific basis for the popularization and application of the latter. The integral finite element model of the structure is built by using the SOLID65 unit and the result of the numerical simulation research is compared with the result of the model experiment. There is good agreement between the calculated data of load-displacement curves, load-strain curve and ultimate bearing capacity with the experimental data, it shows that the result of the numerical simulation is true and reliable, and it can be used for analyzing the structure of the other conditions and true type structure.(3)The engineering rules of the influence factors of the ultimate bearing capacity of the single frame bracing structure of beam aqueduct are discovered combining with numerical simulation. The ultimate bearing capacity and the factors are normalized and it finds that:In operating Case a:The ultimate bearing capacity of the single frame bracing structure of beam aqueduct is not influenced by vertical gravity load, height and span of the bracing structure. The concrete strength and the rebar strength influence the ultimate bearing capacity and the concrete strength is more, the increase of the structural ultimate bearing capacity are respective 0.3 times to the increase of the concrete strength and 0.705 times to the increase of the rebar strength. In operating Case b:The ultimate bearing capacity of Lateral Wind Load is calculated under the action of vertical gravity load. The span of bracing structure has little effect on the single frame bracing structure of beam aqueduct and the fluctuation range of the limit load of structure is 0.327 times to the growth of the frame span, while the height of bracing structure, concrete strength as well as rebar strength impact it significantly and the increase of the ultimate bearing capacity are respectively 2.58 times to the bracing structure’s height opposite,0.204 times to the increase of the concrete strength and 0.19 times to the increase of the rebar strength.