Characteristics Of The Force Structure And Load Test Evaluation For The Long Span Beam-arch-frame Composite Bridge Of V-shaped Pier

A new large-span V-pier arch-beam-frame composite bridge is fully designed with structural features of a compressive arch and a tensile beam and provided with combined effects on them but the forces applied are relatively complicated. This paper focuses on research on the forces applied on this new composite bridge and makes some conclusions through the following aspects, taking the Zhuzhou No. 5 Bridge as a research object.Analysis and research of static characteristics was made on the Zhuzhou No. 5 Bridge using plane bar system finite element programming computation program FBR_CAL_ SUO and DBR_CAL_HUO developed by Professor Li Chuanxi. The results of simulative analysis on construction phase shows that 0# construction and removal of V-leg lever of a large-span V-pier arch-beam-frame composite bridge have great effect on the stresses in triangular frame. During construction of these, monitoring must properly be made for construction. Meanwhile, the correctness of finite element simulative analysis has been validated through stress monitoring in construction phase. The analysis in service phase of a finished bridge shows that shrinkage and creep of concrete has small internal force in and linear effect on this new composite bridge. Meanwhile, the main beam section has very large reserve of compressive stress, which may effectively offset the stress on the bridge adversely affected by the dynamic load and temperature load.A spatially practical model in the rigid frame of the Zhuzhou No. 5 Bridge is established using a large general finite element computation program ANSYS. This paper shows local stress level and distribution law under three most adversely affected working conditions such as construction phase and service phase on the finished bridge of this new composite bridge through analysis on local stresses on bonding portion of arch, beam, and pier as well as the bonding portion of V-leg. It also brings forward some favorable measures to improve performance of mechanical force on local structures.A spatially bar-system model of the Zhuzhou No. 5 Bridge is established using a large general finite element computation program MIDAS CIVIL. An analysis on dynamic characteristics has been made on this bridge in detail in subspace iteration method. It shows the changing laws to the dynamic performance of this new composite bridge under situation with various design parameters and with different boundary simulations and provides for optimization of design of this new composite bridge with references. Loading test on site was carried out on the Zhuzhou No. 5 Bridge. The results of test shows that this new large-span V-pier arch-beam-frame composite bridge has good overall performance of mechanical force and has a bearing capacity and rigid meeting the requirements of relevant codes. The correctness of structure computation model, rationality of design parameters, and correctness of the design theories for this new composite bridge was validated through test.