道桥工程中英文对照外文翻译文献.docx

1、道桥工程中英文对照外文翻译文献中英文对照外文翻译文献(文档含英文原文和中文翻译)英文：1.1Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder Abstract:A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST) arch br

2、idge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST arch rib. The geometric nonlinearity, material nonlinearity。 influenceoftheconstruction process and the contribution of prestressing reinforcement are all taken into consideration. T

3、he accuracy of this method is validated by comparing its results with experimental results. Finally, the ultimate strength of an abnormal CFST arch bridge with stiffening girders is investigated and the effect of construction method is discussed. It is concluded that the construction process has lit

4、tle effect on the ultimate strength of the bridge. Key words: Ultimate strength, Concrete filled steel tubular (CFST) arch bridge, Stiffening girder, Fiber model beam element, Construction process doi:10.1631/jzus.2007.A0682 NTRODUCTION With the increasing applications of concrete filled steel tubul

5、ar (CFST) structures in civil engi-neering in China, arch bridges have become one of the competitive styles in moderate span or long span bridges. Taking the Fuxing Bridge in Hangzhou (Zhao et al., 2004), and Wushan Bridge in Chongqing (Zhang et al., 2003), China, as representatives, the structural

6、configuration, the span and construction scale of such bridges have surpassed those of existing CFST arch bridges in the world. Therefore, it is of great importance to enhance the theoretical level in the design of CFST arch bridges for safety and economy. he calculation of ultimate bearing capacity

7、 is a significant issue in design of CFST arch bridges. As an arch structure is primarily subjected to compres-sive forces, the ultimate strength of CFST arch bridge is determined by the stability requirement. A numberof theoretical studies were conducted in the past to investigate the stability and

8、 load-carrying capacity of CFST arch bridges. Zeng et al.(2003) studied the load capacity of CFST arch bridge using a composite beam element, involving geometric and material nonlin-earity. Zhang et al.(2006) derived a tangent stiffness matrix for spatial CFST pole element to consider the geometric

9、and material nonlinearities under large displacement by co-rotational coordinate method. Xie et al.(2005) proposed a numerical method to determine the ultimate strength of CFST arch bridges and revealed that the effect of the constitutive relation of confined concrete is not significant. Hu et al.(2

10、006) investigated the effect of Poissons ratio of core concrete on the ultimate bearing capacity of a long span CFST arch bridge and found that the bearing capacity is enhanced by 10% if the Poissons ratio is variable. On the other hand, many experimental studies on the ultimate strength of naked CF

11、ST arch rib or CFST arch bridge model hadbeenconducted. Experimental studies on CFST arch rib under in-plane and out-of-plane loads were carried out by Chen and Chen 2000) and Chen et almetrical nonlinearity was significant for the out-of-plane strength and less significant for the in-plane strength

12、. Cui et al.(2004) introduced a global model test of a CFST arch bridge with span of 308 m, and suggested that the influence of initial stress should be considered. The above papers mainly focused on the ultimate strength of CFST naked arch ribs or CFST arch bridges with floating deck. No attempt wa

13、s made to study the ultimate strength of CFST arch bridges with stiffening girders whose nonlinear behavior and CFST arch should be simulated due to the redistribution of inner forces between arch ribs and stiffening girders. In general, stiffening girders can be classified into steel girder, PC (pr

14、estressing concrete) girder and teel-concrete combination girder. It is most difficult to simulate the nonlinear behavior of PC girder, due to the influence of prestressing reinforcement. In contrast to steel or steel-concrete combination beam, the prestressing reinforcements in PC girders not only

15、offer strength and stiffness directly, but their tension greatly affects the stiffness and distribution of the initial forces in the structure. The aims of this paper are (1) to present an elas-tic-plastic analysis of the ultimate strength of CFST arch bridge with arbitrary stiffening girders; (2) t

16、o study the ultimate load-carrying capacity of a complicated CFST arch bridge with abnormal arch ribs and PC stiffening girders; and (3) to investigate the effect of construction methods on the ultimate strength of the structure. ANALYTICAL THEORY Elasto-plastic large deformation of PC girder elemen

17、t The elasto-plasic large deformation analysis of PC beam elements is based on the following fundamental assumptions: (1) A plane section originally normal to the neutral axis always remains a plane and normal to the neutral axis during deformation; (2) The shear deformation due to shear stress is n

18、eglected; (3) The Saint-Venant torsional principle holds in(4) The effect of shear stress on the stress-strain relationship is ignored. The cross-section of a PC box girder with onesymmetric axis is depicted in Fig.1, where, G and s denote the geometry center and the shear center re-spectively. Acco

19、rding to the first and the third as-sumptions listed above, the displacement increments of point A(x,y) in the section can be expressed in terms of the displacement increments at the geometry center and the shear center as where Ktoris the coefficient factor which is related to the geometry shape of

20、 the girder cross-section. Similar to 3D elastic beam theory, the displacement increment of the girder can be expressed in terms of the nodal displacement increments as in which L denotes the element length, and z is the axial coordinate of the local coordinate system of an element. Then, the displa

21、cement vector of any section of the element can be written as where u is the displacement vector of any section of the beam element, N is the shape function matrix and ue is the displacement vector of the element node. They are respectively expressed as According to Eq.(2), the linear strain can be

22、ex-pressed as in which BL is the linear strain matrix of the element Correspondingly, the nonlinear strain may be expressed as where BNL is the nonlinear strain matrix of the ele-ment The stress increment can be approximated using the linear strain increment as where D is the material property matri

23、x. Neglecting the influence of the shear strain, D can be expressed where E() is the tangent modulus of the material which is dependent on the strain state, and G is the elastic shearing modulus regarded as a constant. According to the principle of virtual work, we have in which and are the stress v

24、ector and stress increment of the current state, q and P are the dis-tributed load and concentrated load vector, q and P are the increments of distributed load and concen-trated load, u and are the virtual displacement and virtual strain, and V is the volume of the element. Substitute Eqs.(9), (11)

25、and (14) into Eq.(16) and ignore the infinitesimal variable N, we have where Fe is the increment of element load vectorcorresponding to ue, the element displacement vec-tor. Kepand K are the elasto-plastic and geometric stiffness matrixes of the beam element respectively as follows The distribution

26、of elastic and plastic zones is non-uniform in the element, and varies during de-formation. It is very difficult to present an explicit expression of the property matrix D for the whole section. Hence, the section is divided into many subareas, as shown in Fig.2, and the fiber model is adopted to ca

27、lculate the elements stiffness matrix, i.e.Obviously, if the number of subareas is suffi-ciently large, the result of Eq.(19) will approach the exact solution. The value of Kep is calculated using numerical integration, with Di being regarded as i. To compute the geometric stiffness matrix K, the no

28、rmal stress should be expressed in terms of axial force and bending moment, which actually has very little contribution to the geometric stiffness, so where N is the axial force, and A is the sectional area. Prestressing reinforcement element The reinforced bars parallel to the beam axis may be rega

29、rded as fibers, whose contributions to the stiffness could be readily accounted for in Eq.(19). The contributions to the stiffness from those not par-allel to the beam and the prestressing reinforcement (PR), will however be calculated in the following section. The displacement increment of two ends

30、 of the prestressing reinforcement in Fig.3 can be expressed by Eq.(21): n which kep and kare respectively the elasto-plastic and the geometric stiffness matrixes, is the nodal displacement vector, and f is the nodal force vector of the prestressingreinforcement element in the local coordinate syste

31、m. According to Fig.4, and f can be written in the form Then the stiffness matrix ep( k + k)of the rein-accordingly. CFST arch rib, steel girder or steel-concrete girder element The fiber model mentioned above can also be used to simulate the CFST arch rib, steel stiffening girder or steel-concrete

32、composite stiffening girder, with similar elasto-plastic stiffness matrix and stiff-ness equation. The detailed description of the deduction can be found in (Xie et al., 2005). However, for the CFST arch rib, the stress-strain relation of structure is very complex due to the com-bined influence of the confined concrete and outer steel tube. In this paper, the following stress-strain relation considering the confinement effect of the steel tube ring (Han, 2000) is adopted: where ytand ycare the yi