Experimental Study on Torsion Resistance of Foundation Ring Land-Based Wind Power Expanded Foundation Scale Model

In this paper, an experimental torsion resistance-loading system for wind power extended foundation scale models is taken as the research object, and four 1:3 scale model specimens of the foundation ring are tested. The transmission mechanism of torque load in the extended foundation was analyzed, and the proportion of each part bearing the torque load was calculated. Test results showed that when the torque load was small, the torque load transmitted from the upper part was mainly borne by the sidewall adhesion force, as well as the top radial reinforcement. In contrast, the torque load was gradually borne by the anchor flange of the foundation ring in the case of a large torque load. At the middle and late stages of torque loading, the top radial reinforcement of the foundation shared about 20% of the torque load, while the bottom flange of the foundation ring shared about 80%. The torque load is most sensitive to changes in the size of the bottom flange but not sensitive to those in the embedded depth of the foundation ring or in the strength of the foundation concrete.

The Research on Shallow Tunnels Construction Technology

By using the numerical analysis method as the test means, this paper simulated and studied the main factors of ground loss which was caused by the full face excavation of shallow tunnels. The results of the numerical experimentation make clear that: in the same conditions, the inverted arch reinforcement is more effective than the vault reinforcement, the advanced reinforcement of inverted arch is more effective than Radial reinforcement of that, and the vault reinforcement doesn’t work or the effect isn’t obvious.

Über die mechanische Bedeutung der Holzstrahlen | The mechanical relevance of wood rays

Three investigations into the mechanical relevance of wood rays were combined for this article. The main objective was to show, that, apart from physiological functions, rays also significantly influence the radial strength and stiffness of wood. In the first approach twelve deciduous tree species with various proportions of fractions of rays were examined for their transverse tensile strength and stiffness. The second approach was based on the comparison of the radial mechanical properties of wood with a very high proportion of fraction of rays and beech wood with a normal volume. In these two investigations the mechanical relevance of rays could only be deduced indirectly. By isolating big rays of beech and carrying out tensile tests on the tissue, we found direct evidence for the mechanical relevance. The results are discussed with regard to their biomechanical relevance. The importance of a radial reinforcement for the wood is underlined. Moreover, the principle of multi-functionality in nature is emphasized in keeping with a possible transfer of biological design to technical solutions.