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Elastic-plastic analysis for a cracked plate with finite dimensions is significant in engineering, however, such analysis is difficult because it cannot be confined by the usual small scale yielding. By using the near crack line analysis method, however, a cracked plate with finite dimensions can be easily analysed.An antiplane stationary crack and an antiplane quasistatically growing crack in an infinite plate in an elastic-perfectly plastic solid has been analysed by Yi [1,2] by using the near crack line analysis method. Although one of the small scale yielding conditions, which states that the plastic zone is small enough that the elastic field out of the plastic zone is the dominant field for a crack (i.e., the K-dominant field), had been abandoned by using the exact elastic field to match with the plastic field; another condition of the small scale yielding, that the elastic field is moved to some location along the crack line, had not been given up. Further analyses corresponding to [1] and [2] have been given by Yi [3,4], where the small scale yielding conditions have been given up entirely. Meanwhile, a cracked plate with finite dimensions under stationary condition has been successfully analysed in [3].In this paper, an antiplane quasistatically growing crack in a centre cracked plate with finite dimensions in an elastic-perfectly plastic material, as depicted in Fig. 1, will be analysed by using the near crack line analysis method. The crux of the matter is to obtain the reasonable form of the near crack line elastic field for the cracked plate.The elastic stresses of a cracked plate with finite width are hard to obtain. But near the crack line region they can be built by modifying the elastic stresses of a corresponding infinite plate.The exact elastic stresses of a corresponding infinite plate are % = ImZ and xyz = ReZ, where Z = "C. a / z~--~-a 2 Int Journ of Fracture 73 (1995)

Abstract. The semi-empirical and semi-theoretical method was adopted to simulate the response of gas continuous buried pipelines subjected to Rayleigh wave propagation. Using two earthquake damage states and normal distribution assumption, seismic failure probabilities of pipelines were calculated. The weighted statistical average method was introduced to estimate seismic failure probability of pipeline network. The relations between seismic failure probability, earthquake damage grade and seismic risk level for pipeline network were presented to determine earthquake damage grade and earthquake damage level with respect to seismic intensity. According to the results of numerical example, it is concluded that the gas buried pipelines and its network due to Rayleigh wave propagation effects have high seismic failure risk under seismic intensity above grade Ⅶ.