Analysis Of Temperature Effect Of Prestressed Concrete Continuous Rigid Frame Bridge

The stress and deformation under the temperature load is one of the main factors affecting engineered quality. With the development of hollow high-rise pier bridge and wide span pre-stressed concrete box-girder bridge, the effect and jeopardize brought by the temperature stress are increasingly concerned by the engineers.By reading numerous references, the author illustrates the characteristic of the theory of temperature distribution and sunlight temperature field of concrete box structure. The primary factors affected the distribution of sunlight temperature; the effect of sunlight temperature field on concrete box structure and the calculation theory of temperature difference stress are studied extensively. Meanwhile, combined with the practical example of Shiman Expressway Gangou Bridge, the author analyses the principle of temperature distribution during the curing of concrete and the stress effected by the temperature. The sun light thermal grads difference effect among the present and past standards of highway engineering in China and those in some foreign countries is analyzed with the help of general finite element programs. Compared with the difference between those standards of highway engineering of continuous rigid frame bridge affected by sun light thermal difference effect, some conclusions can be drawn.Previous studies illustrated that the hydration heat generated by the inner of concrete and the temperature in the box-girder have the characteristic of irregular, lateral and vertical non-homogeneity at the beginning of concrete pouring. Different models calculating the temperature gradient have different varying a large range. The specifications for design of highway bridges and culverts in China for both ascending temperature and descending temperature are quite smaller than those defined by those specifications in Britain (BS-5400) and New Zealand. This paper suggests that designers should consider the illogicality of our specification and design according to overseas relative specification.