Showing papers by "Fang-Le Peng published in 2005"

Longitudinal shear transfer of tunnel and its 1d analytical solution

Abstract: By analysis of the internal force components in longitudinal and cross sections of a circular tunnel and their correlations under uneven subsidence,based on the elastic foundation beam(EFB) theory and potential theory,the concept of longitudinal shear transfer and its solution are proposed. In addition,additional internal forces produced by longitudinal shear transfer under 4 typical forms of subsidence are analyzed and it′s concluded that the additional internal forces vary significantly with the subsidence forms and the critical values turn out not to be at the places of maximum subsidence. It′s suggested that the effect of longitudinal shear transfer should be taken into consideration for improved tunnel design.

A work-hardening and softening constitutive model for sand: modified plastic strain energy approach

Abstract: The paper describes an energy-based constitutive model for sand, which is modified based on the modified plastic strain energy approach, represented by a unique relationship between the modified plastic strain energy and a stress parameter, independent of stress history. The modified plastic strain energy approach was developed based on results from a series of drained plastic strain compression tests along various stress paths on saturated dense Toyoura sand with accurate stress and strain measurements. The proposed model is coupled with an isotropically work-hardening and softening, non-associtated, elasto-plastic material description. The constitutive model concerns the inherent and stress system-induced cross-anisotropic elastic deformation properties of sand. It is capable of simulating the deformation characteristics of stress history and stress path, the effects of pressure level, anisotropic strength and void ratio, and the strain localization.