Study On Mechanical Properties Of Assembled High-speed Railway Protective Wall Of Under Lateral Load

As a part of the auxiliary facilities of the bridge,the protective wall is vital to the safety of driving.In high-speed railway,the traditional protective wall is cast-in-place.However,due to the strong intersections of the bridge deck,the construction quality is not easy to be controlled and the construction period is long.Assembly type protective wall,not only to achieve factory construction,quality control easy,short construction cycle,and green environmental protection,in line with the development trend of the industry.Based on the new-Beijing to male Ann high-speed rail prefabricated bridge deck system as the research background,the finite element software method to study the mechanics properties of the fabricated protective wall,through the analysis of the influence of different factors on the fabricated protective wall mechanical properties,puts forward the corresponding improvement measures,improve the carrying capacity of the fabricated protective walls.The main research contents of this paper are as follows:(1)To determine a standard model for simulating an assembled protective wall,this paper establishes four different models of the fabricated protective wall by using finite element software,and compares them with the mechanical properties of the fabricated protective wall in the field.The results show that,when analyzing the mechanical properties of the assembled protective wall structure,the results of different simulation methods are consistent with the actual state of stress,but there are some deviations,among which the model considering the refinement of bolt connection has the highest consistency with the field test results.(2)The mechanical properties and failure modes of the fabricated and cast-in-place protective walls are different,this paper based on the refined model of the fabricated protective wall,the mechanical properties and failure modes of the cast-in-place integral protective wall are compared.The results show that the ultimate bearing capacity of the cast-in-place protective wall is213.05kN/m,and that of the fabricated protective wall is 163.85kN/m,which is about 23.09%different from the former.At the same time,under the action of horizontal load,the two show different failure modes.The assembled protective wall breaks along the thickness direction of cable trough floor,while the whole one cracks and breaks at the abrupt position of the section of the protective wall.(3)According to the influence of different factors on the load-carrying capacity of the assembled protective wall,this paper based on the differences between the mechanical properties of the fabricated protective wall and the cast-in-place integral protective wall,the influences of the number,diameter and fixing mode of the connecting bolts of the fabricated protective wall,the reinforcement ratio of the structure and the concrete strength grade on its bearing capacity are studied.Research has shown that change the way connecting bolts and prefabricated protective wall contact to improve the carrying capacity of the fabricated protective wall is the most effective,and when near the side protective wall connecting bolts is set to 3,as the ultimate bearing capacity of the protective wall of 197.33 kN/m,differ with monolithic 7.4%,and overall stiffness have significantly improved.The research results provide a scientific basis for the popularization and application of the assembled protective wall.