In this paper it is shown that compacted wheat straw block is a cost effective building material in China. Wheat straw is renewable resource and ecological material, when used as building material; it is less energy and material consumption. The compacted wheat straw block has a small thermal diffusivity and good fire resistance. The hydraulic properties will guarantee a comfortable humidity of in door air, and protect the material from rot, and ensure the durability of the construction. The mechanical properties will also increase the structure safety. It is absolutely a cost effective building material.

In this paper, a storage cell for the high level radioactive wastes is studied in order to identify and demonstrate the coupled phenomena evolving in the high level radioactive wastes (HLW) storage. According to the various important processes in the storage structures, special attention is paid on the coupling elastoplastic and viscoplastic damage processes in short and long term. In the calculations, the complicated thermo-hydro-mechanical coupling process has been taken into consideration. These numerical calculations allow us to obtain some quantitative results describing the mechanical behaviour and coupling thermo-hydro-mechanical processes for a short-and long-term in the storage cell.

This paper contributes to numerically study the mechanical behavior of cement paste under compressive pressure. First, the main results from an experimental study on the mechanical behavior of cement paste are studied. Then an elastoplastique model with two flow mechanisms is proposed to describe the mechanical behavior of cement paste subjected to confining pressure. A particular emphasis is put on the pore collapse mechanism which is developed at higher confining pressure. Finally, numerical simulations and experimental data are compared in order to verify the capacity of the proposed model to reduce numerically the basic characteristics of cement paste under different levels of confining pressure.

The mechanical behavior of a compacted unsaturated clay soil was experimentally investigated. Volume changes were investigated using a conventional odometer cell under a series of constant confining pressures, following a wetting path. The special loading paths were utilized to reflect field conditions associated with the compacted earth structure in earth filled embankment. The soils used in the experiments were taken from an earth dam. The compacted specimens were consolidated under k0-oedometer conditions. The volume change and the water content variation were measured during the tests. The influence of the confining pressure and the initial water saturation were taking into considerations. The experimental results show that the volumetric deformation properties of the remolded unsaturated soil could be expansive and/or contractive, depending on the confining pressure and the initial water saturation. It is also observed that for the mediate confining stress, there volumetric deformation of specimen applied to wetting loads has a transition from dilation to contraction.

Free field response of partially saturated sands to cyclic loading, with a particular attention to soil liquefaction has been studied. The study has been conducted using a numerical model elaborated for the liquefaction of partially saturated soils together with a cyclic elastoplastic constitutive relation implemented in a finite element program. The numerical model and the analysis of the influence of soil saturation on the free field response, for different positions of the water table have been investigated respectively. The result shows that the soil saturation degree largely affects the free field response to cyclic loading, with a decrease in soil saturation leading to a decrease in the rate of generation of excess pore-water pressure, and consequently to a reduction in the liquefaction risk.