The Research On Static Behavior Of Reinforced Concrete Rigid Framed Arch Bridge Without Spandrel Members

As a new type of structure,the rigid framed arch bridge without spandrel members is built with a small number,and most of them are prestressed concrete.At present,the research of this direction is mainly focused on the prestressed concrete rigid framed arch bridge without spandrel members,while the research on the reinforced concrete rigid framed arch bridge without spandrel members is less.In this paper,the static performance of reinforced concrete rigid framed arch bridge without spandrel members is carried out in the background of a reinforced concrete rigid frame arch bridge without spandrel members.The main work and results are as follows:(1)By using Midas/Civil finite element software,the space bar model is established to calculate and analyze,it is concluded that the arch leg bears is under the combined action of compression and bend,the main girder of the triangular area bears is under the combined action of tension and bend,and the main beam in each span is under the combined action of compression or tension and bend.The effect of the temperature load on the structural system is very obvious,in which the overall lift temperature has great influence on the structural stress,especially the tensile stress caused by the cross arch feet is very large.The result of RC checking shows that although there is no over standard crack in the reinforced concrete rigid frame arch bridge without spandrel members,the calculated value of crack is large.(2)The Midas/Civil finite element software is applied to simulate the construction process of the reinforced concrete rigid frame arch bridge without spandrel members.The stress values,counter-force values and vertical displacement values of different construction schemes under different construction conditions are compared and analyzed.It is suggested that we should first pour the triangular section then pour the middle span beam,and the sequence of removing scaffolds is from the two sides to the middle one by one.(3)The main parameters including arch axis line,sagittal span ratio and span ratio are studied,and the force of the structure is better than the arc line and the parabola when the arch axis is the catenary under the constant load and the live load.Under the constant load,the change of the vector span ratio has great influence on the force value of the middle span of each span and the bending moment value of each cross arch,and in general it increases with the decrease of the vector span ratio;under the action of live load,along with the decrease of the vector span ratio,the axial force value shows an overall increasing trend,and the span moment values also increase.Under the condition of dead load,the axial force values of every span arch foot decrease with the increase of the side span ratio,and the span moment values increase as a whole,under the action of live load,with the change of the span ratio,the axial force value changes smoothly,and the bending moment decreases with the increase of the side span ratio.(4)The software Abaqus is used to model the triangular area with complex force and structure.The results show that after the completion of the construction the tensile stress in the 1# triangle area is located at the lateral of the arch rib of the sub side cross arch rib,and the tensile stress in the 2#triangle is located at the lateral of the middle span arch rib of the middle span arch rib.After ten years of the bridge constructed the tensile stress in the 1#triangle area is located at the inner side of the arch rib of the sub side cross arch rib.The tensile stress in the 2#triangle area is located at the bottom of the main beam span and the main beam surface near the sub side and in the local region.