Study On The Influence Of Arrangement Form Of Shape Steel On The Working Performance Of The Steel Reinforced Concrete Radial Gate Pier

The gate pier is a key part of the water release structure,which directly affects the operation safety of the entire water control project.With the rapid development of water conservancy,large discharge and high head hydropower station are rising;the requirements for bearing capacity of gate pier are also getting higher and higher.With the effect of topographic and geologic conditions,layout of hydro-project and other factors,the thickness of pier is restricted.The application of pre-stressed gate pier,to a certain extent,improved the bearing capacity,but the stress relaxation of pre-stress anchorage cable and the improvement of seismic performance haven't been solved effectively.Steel reinforced concrete has the characteristics of strong bearing capacity,high rigidity,good ductility and so on,there have been some achievements in the research on the application of the steel reinforced concrete to the gate pier to improve its bearing capacity.However,these researches are focused on the research of gate pier with single shape steel on both sides.This paper combined with the characteristic of stress distribution of gate pier,by arranging a plurality of shape steels in the gate pier to study how the arrangement form of shape steel to influence the performance of gate pier.In this paper,we respectively establish single-steel and multi-steel gate pier model by the finite element software ANSYS,holding the principle of constant quantity of steel in tensile zone of gate pier.Combined with the characteristics of stress distribution of pier,the number of shape in steel gate pier is set as two and three,and the spread angles of the shape steel in gate pier are 20 degrees,25 degrees,30 degrees and 40 degrees respectively.In this paper,from the aspects of displacement,stress,crack distribution and bearing capacity of gate pier,the influence of the arrangement form of shape steel on the performance of the pier is studied.The analysis shows following conclusions:(1)Under the symmetrical load,when the spread angle between shape steels is constant,the maximum displacement of the pier decreases with the increase of the number of shape steel.When the number of shape steel remains unchanged,with the increase of the spread angle,the maximum displacement of the gate pier decreases first and then increases.Under the asymmetrical load,when the spread angle of shape steel is set as 20 or 25 degrees,gate pier with two shape steels has the smaller maximum displacement;when the spread angle of shape steel is set as 30 or 40 degrees,gate pier with three shape steels has smaller maximum displacement.When the number of shape steel in gate pier remains unchanged,with the increase of the spread angle of shape steel,the maximum displacement of the gate pier decreases first and then increases.(2)Under the symmetrical load,when spread angle between the shape steels is constant,the stress of control point in gate pier decreases first and then increases in multiple shape steel gate pier.When the number of shape steel in the gate pier remains unchanged,with the increase of the spread angle,stress of control point in gate pier decreases first and then increases.Under the asymmetrical load,the number of shape steels in gate pier has little influence on the stress of the control point in the gate pier.When the number of shape steel in the gate pier remains unchanged,with the increase of the spread angle,the stress of control point in gate pier increases.(3)The development of cracks in multiple shape steel gate piers is slower than that of single shape steel gate pier.Under the symmetrical load,the arrangement form of the shape steel in multiple shape steel gate piers have little influence on the development of the cracks.Under the asymmetric load,the spread angle between shape steels has great influence on the development of IV cracks in gate pier.In the early stage of crack expansion,gate piers with small spread angle of shape steels have a slower development in crack,with the proliferation of pier cracks,gate piers with large spread angle of shape steels have a slower development in crack,cracks spread rapidly outside the range of the shape steel.The number of shape steel in gate pier has little effect on the development of cracks.(4)Under the symmetrical load,when the spread angle of shape steels in gate pier remains unchanged,the bearing capacity of gate pier increases gradually with the increase of the number of shape steel.when the number of shape steel remains unchanged,with the increase of the spread angle,the bearing capacity of gate pier increases first and then decreases.Under asymmetrical load,when the spread angle remains unchanged,the load capacity of the two shape steel gate pier is the strongest.When keep the number of shape steel unchanged,the bearing capacity of the pier decreases gradually with the increase of the spread angle of shape steel.(5)Considering from the aspect of displacement,stress,cracks distribution and bearing capacity of the gate pier,the arrangement form of three shape steels arranged at an angle of 25 degrees in gate pier is relatively well.