Accounting for horizontal torsional vibrations of foundations when calculating seismic load

The article presents a method for calculating in-plane vibrations of building structures under seismic load taking into account the possibility of foundation displacement, which is similar to horizontal torsional vibrations when calculating earthquake forces. The method is illustrated by the structural design of a seven-storey tower-like building with a massive foundation. We develop transfer functions for a massive rigid body, which are subsequently used for calculating the response of the foundation subject to base shears and moments applied to the outer plane of the foundation under seismic forces. The structural calculations conducted for ductile structures with the first frequency of ~2.4 Hz and for more rigid structures with the first frequency of 7.1 Hz showed that, depending on the building stiffness, reduced seismic forces increase by 1.5–2 times. According to the results obtained, when designing structures in areas of high seismic hazard, account should be taken of possible foundation flexibility effects depending on different types of soil and structural solutions of particular buildings.

Cultural marginality and its social implications

The article is devoted to exam the problem of cultural marginality. Due to the fact that nowadays, during the formation of new social forces and relations, many societies, including Kazakhstan’s, more-less experience a vacuum of values and norms. Marginal individuals in the conditions of new landmarks formation are lacking the stable social orientations; it is very hard for them to identify themselves with sufficient certainty. A marginal state characterizes by the fact that a human, having left one culture, leaving it on the outer plane of his being, does not fit into a culture new for him, does not come to it, although he lives in the presence of its innumerable displays. The individual is in the stage of mastering new cultural features, but he cannot yet master them completely. This is the marginality as the natural paradox for being transitional, borderline social and cultural status. Usually, it is precisely in transition eras that the process of marginalization intensifies sharply and expands in its scale. People feel insecure and socially unstable. In this regard, the purpose of this article is to thoroughly exam the problem of marginality. In writing the article, we used the methods of cognitive-evaluative analysis, the methodology of cross-cultural-psychological research and the principle of the historical traditions unity. Based on the research of marginality problem, we conclude that the personality absorbs single and diverse, whole and detailed, universal and individual. In this regard, the problem of marginalization should be resolved through personal self-determination. This article was written by virtue of the works of various philosophers, sociologists and educators who studied the problems of marginality. The article offers a number of recommendations for solving the problem of marginality in the new realities.

Micro-mechanical analysis of the pineapple-reinforced polymeric composite by the inclusion of pineapple leaf particulates

The present study is focused on investigating the effect of the micro-mechanical properties of the natural fiber- (pineapple leaf fiber) reinforced polymeric composites by the addition of pineapple leaf micro-particulates. For the investigation, a two-step approach has been used. In the first step, finite element method-based analysis has been used to characterize the tensile and shear properties of the pineapple leaf fiber-reinforced polymeric composites (FRP) and pineapple paticulate-reinforced polymeric composites (PRC), and the adopted finite element method-based analysis has been validated through the experimental approach. In the second step, the validated finite element method-based analysis has been used to characterize the micro-mechanical properties of the hybrid fiber-reinforced polymeric composites (HFRP) fabricated using the pineapple leaf micro-particle embedded epoxy as a matrix material and the pineapple leaf fiber has been used as reinforcing material. It has been observed through the analysis that the micro-mechanical properties of HFRP were superior to that of FRP. There has been a 10.16% increment in Young’s modulus in the longitudinal direction and a 26.36% increment in Young’s modulus in the transverse direction for HFRP over FRP. Further, a 9.91% increment for in-plane shear modulus and 26.17% increment in outer-plane shear modulus have been observed for HFRP in comparison to FRP. These results suggest that pineapple leaf particulates are good reinforcing materials to enhance the transverse direction and outer plane micro-mechanical properties of the fiber-reinforced composite.

Theoretical analysis of the influence of plane control network on lateral breakthrough error of long immersed tunnel

There is extremely strict precision requirement for the lateral breakthrough error of long immersed tunnel in the offshore island and tunnel project, but the point location layout range of the outer plane control network is limited in the artificial island, and the space inside the tunnel is long and narrow, which is not conducive to high-precision through-measurement control. In order to further reduce the influence of the error of the plane control network on the lateral breakthrough error of the immersed tunnel, a mathematical model of the influence of the lateral breakthrough error caused by the orientation direction of the outer control point and the position of the breakthrough point has been established through the theoretical analysis in this study, and the favorable orientation directions and the favorable penetration point are analyzed. It is suggested through simulation analysis that the direction that is as consistent with that from the entrance (outlet) point to the penetration point as possible is as the advantageous orientation, which could minimize the lateral penetration error and ensure high-precision rendezvous and docking of the immersed tunnel. This study is instructive for similar engineering practices.

KINEMATICAL FEATURES OF FORMATION OF A FLANGE WITH MINIMUM TENSION OF A TRANSIENT TOROIDAL SURFACE

The technology of plastic forming of wide flanges in tube billets with the predicted length of the transitional toroidal section between the outer plane of the flange and the internal cavity of the pipe is proposed. The procedure for calculating the length of this section is given. In order to eliminate the toroidal portion in the flange formed during the flanging of the pipe, it is proposed to perform its plastic shaping by depositing the cylindrical part of the workpiece. Equations for calculating the extent of the free surface on the toroidal part of the workpiece when it is shaped, depending on the coefficient of contact friction and the presence of a radial support of the flange are obtained. The variant of forming in the flange the toroidal section in the stamp with the compensation cavity is proposed. Equations for calculating the deformation force and the extent of the free surface are given.