Study On Program Development And Checking Method Of Bearing Capacity Of Long-Span Arch Bridge

Arch bridge is one of the bridges which are built most in China, especially in western district for special geographical environment and good geological condition. At present the methods of calculating arch bridge are reading up the literature and Finite Element. The former is that the edited comprehensive literature of the arch bridge calculation is used by designer for calculating. However, its falt is enormous calculation and low efficiency; the literature can't be used because the arch-axis coefficient isn't given in advance when the effect of the concrete's contraction and creep is considered to a long-span arch bridge. The latter is that the program of the finite element is employed for inner force and deformation. There are some advantages such as fast calculation speed and calculating of inner force to an arbitrary arch-axis coefficient, though the model establishment is complicated, and it can not realize optimization of arch-axis coefficient to normal program of the finite element. So it has practical significance that the program of arch bridge calculation for special use is development on the day of the extremely developed program of the finite element.In the wake of improving of road grade, increasing of overweight traffic, weakness of designing and curing, aging of bridge's material and environment impact, many arch bridges has some diseases such as falling of the bearing capacity, increasing deformation and crack in these years. The means of increased section is usually used in reinforcement of arch bridge, but there is no matching way of checking bearing capacity to this day.Based on expounding development of arch bridge and status of way of checking bearing capacity, the fomula of arch bridge calculation is deduced suitable for developed program according to theory of classic arch bridge for theory of program. In view of problem about checking bearing capacity in reinforcement of arch bridge using increased section, the formula of limit state design method of revised coefficient is put forward, which is no difference with specifications in force on the form. The specific example is offered for comprehension. At last the program of inner force calculation and checking bearing capacity of long-span arch bridge developed by author with Visual Basic Language 6.0 is emphatically introduced, which has the capable analytical function and friendly user interface. It can be completed that not only optimization of arch-axis coefficient, calculation of dead load of uniform cross section, variable cross section, deck type and half-through arch bridge, of live load of specifications about 85 and 2004, of addition force of temperature change, concrete's contraction and creep, foundation settlement and of checking of bearing capacity, but also estimate of bearing capacity of old arch bridge and checking it after reinforcement using increased section. The program developed by author can remedy the defect that calculation of arch bridge is lack of program for special use.