| Under the development concept of building industrialization,the country had introduced a series of standards and specifications for fabricated structures in recent years,and developed relevant policies to promote its development.The construction of the valve hall structure of the converter station was a key link in Chinese transmission engineering,its construction period and quality directly affected people's daily life.However,the traditional cast-in-place valve hall structure was not in line with the requirements of the times.Currently,many scholars had studied the assembled concrete firewall panels of the valve hall structure.However,there was still a lack of research on fabricated concrete column-column joints.This paper took the structure of an embedded assembly firewall valve hall as the research object,its structural form was steel frame-reinforced concrete structure system,the maximum internal force of the column end was obtained by its overall finite element analysis.In combination with the test conditions,the cast-in-place concrete shaped columns reserved with wall panel slot was selected,and the newly proposed column-column joint connection form was applied to design and manufacture a new fabricated concrete column test piece,the quasi-static test and finite element software were used to analyze seismic performance of the joint.The specific work was as follows:1.According to the design parameters and load information of the actual valve hall structure,SAP2000 was used to establish the overall finite element model of the equivalent single-bar tilting valve hall structure,in which the single pole was the equivalent replacement of the embedded wall panel in the overall frame.Through the modal analysis of the structure,it was known that the torsion was large,and the maximum internal force of the column end under the combination of various load conditions was obtained by the overall calculation,which can be used as the internal force reference value for the design of the test piece.2.Based on the cast-in-place concrete column in the valve hall structure,combined with the test conditions,three new fabricated concrete column specimens were designed and fabricated,and their seismic performance was studied by pseudo-static test.The test phenomenon showed that the angle steel not only had good deformation ability,but also could effectively inhibit the development of cracks.The test results showed that the hysteresis curve of the new fabricated concrete column was full,and the equivalent viscous damping coefficient was greater than 0.1,and the displacement ductility coefficient was not less than 3,which indicated that the new fabricated concrete column joint had good seismic performance.3.The finite element model consistent with the specimen was established by ABAQUS,and the finite element analysis results were compared with the experimental results to verify the accuracy of the modeling method.In addition,the finite element model of the test piece was compared with the analysis results of the cast-in-place and pure grouted sleeve finite element models to study the change of bearing capacity.4.The influence of different angle steel strength and axial compression ratio on the mechanical behavior of new fabricated concrete columns was studied by using the finite element model of the test piece.It was found that the appropriate angle steel strength could increase the ultimate bearing capacity of the joint;the ultimate bearing capacity of the column increased with the increase of axial compression ratio within a certain range. |
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