| Two-polyline Arch Reinforced Concrete Frame Structures refer to the reinforced concrete frame structures in which the frame beam is two-polyline.They are better than steel light structures in terms of structural performance.This kind of frame is used in large public buildings such as highway service building and passenger station.However,two-polyline arch reinforced concrete frame is not good for the frame column when it is subject to vertical.This disadvantage effect mainly comes from the two-polyline reinforced concrete beam ends.This mechanical property is similar to an arching effect to increase the horizontal displacement of the column upper.To solve this problem,the prestressed technology and steel are considered.In recent years,there have been some engineering research and application on the prestressed concrete structure and the prestressed steel reinforced concrete structure according to overseas and domestic research status.Whereas,there is a lack in research and analysis of the two-polyline arch prestressed steel reinforced concrete frames.In this paper,the mechanical properties are studied which the two-slope polyline arch reinforced concrete frame and the two-slope polyline arch prestressed steel reinforced concrete frame.Firstly,the two-slope polyline arch reinforced concrete frame and the two-slope polyline arch prestressed steel reinforced concrete frame were designed for a building of structural concrete applied in Shandong Province motorway service areas,and the third point loading tests were completed.Then,the calculation method of flexural bearing capacity was studied for two-slope polyline arch prestressed steel reinforced concrete frame.Moreover,the finite element analysis were builded for the two-slope polyline arch reinforced concrete frame and the two-slope polyline arch prestressed steel reinforced concrete frame using ABAQUS software,and the influence of different parameters on the moment modulation coefficient of the two-slope polyline arch reinforced concrete frame and the two-slope polyline arch prestressed steel reinforced concrete frame ware analyzed.Finally,the two-polyline arch prestressed steel reinforced concrete frame's internal damage was monitored by AE instrument in the experiment,and damage index models were putted forward bending on the AE cumulative counts and cumulative energy parameters.The main works of this paper are as follows:Firstly,design and vertical static test of the two-polyline arch reinforced concrete frame and the two-polyline prestressed reinforced steel concrete frame were finished.The failure mode,cracks distribution,ductility coefficient and other mechanical properties of two-polyline arch reinforced concrete frame and the two-polyline prestressed steel reinforced concrete frame were studied.The results showed that the ductile failure happened in the two-polyline arch reinforced concrete frame beams and the two-polyline prestressed reinforced steel concrete frame beams during the process of loading.The internal force redistribution were happened and the three-hinge failure mechanism were formed.The ductility coefficients are 2.53 and 2.63 respectively.The moment modulation coefficients are28%and 37.66%,and higher than the code value of 10%-20%.Useing prestressed and steel structures could enhance the crack-loading.Secondly,the calculation method of the secondary internal force,pressure arch acting,two-polyline arch prestressed steel reinforced concrete frame's flexural bearing capacity were studied.The results showed that the ratio of the calculated ultimate load and the test is 0.94and 0.85 respectively,which shows that the method can calculate the flexural bearing capacity of two-polyline arch prestressed steel reinforced concrete frame and two-polyline arch reinforced concrete frame.The calculation results are conservativeThirdly,the finite element analysis models were builded by using ABAQUS software for the two-polyline arch reinforced concrete frame and the two-polyline arch prestressed steel reinforced concrete frame.The influence parameters of moment modulation coefficient were investigated such as depth of compress zone,slope angle of beam,effective prestress,steel ratio and so on.The results showed that the established finite element model could simulate the loading process of the test.The factors such depth of compress zone,slope angle of beam,effective prestress,and steel ratio could obvious influence on the moment modulation coefficient,and the slope angle of beam has the greatest influence compared with other parameters.The steel ratio,depth of compress zone,effective prestress are negatively correlated with the moment modulation coefficient.Finally,the two-polyline prestressed steel reinforced concrete frame's internal damage was monitored by AE instrument in the experiment.The internal damage evolution was analyzed through the collected data.D_N and D_E are calculated by ratio of the AE cumulative counts and cumulative energy and total AE cumula tive counts and cumulative energy.By the contrast with the statistic damage values,the results showed that the damage index model base on the cumulative conuts and cumulative energy could evaluate the damage of two-polyline prestressed steel reinforced concrete frame credibly. |
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