“豫灵人”发现区的地貌

本文从地貌基本特征、地貌形态结构和地貌形成演变等三方面,论述了豫灵人发现区的地貌。     

“豫灵人”发现区第四系与古人类相关问题分析

本文通过对“豫灵人”发现区地壳发展历史和第四系成因类型的分析,提出了“豫灵人”发现区古人化石所在地的中更新统上部地层是本区继续寻找发现古人化石和旧石器的重要地区与地层之一。     

Seismic ground amplification induced by box-shaped tunnels

The growing use of underground structures, specifically to facilitate urban transportation, highlights the need to scrutinize the effects of such spaces on the seismic ground response as well as the surrounding buildings. In this regard, the seismic ground amplification variations in the vicinity of single and twin box-shaped tunnels subjected to SV waves have been investigated by the finite difference method. To evaluate the effects, generalizable dimensionless diagrams based on the results of parametric numerical analysis considering factors such as variations in the tunnels’ depth, the distances between the tunnels, tunnel lining flexibility, and input wave frequency, have been presented. In addition, to assess the effects of underground box-shaped tunnels on the response spectrum of the ground surface, seven selected accelerograms have been matched based on a specific design spectrum for the stiff soil condition of Eurocode 8 (CEN, 2006). The results underline the significant amplification effect of the box-shaped tunnels on the ground motions, specifically in the case of horizontal twin tunnels, which should be given more attention in current seismic design practices for surface structures.

     

三门峡盆地“豫灵人”发现区古地理环境的探讨

本文通过“豫灵人”发现区的地质构造、黄河演进、地层层序、地貌形态以及古生物等方面的分析与研究,提出了本区第四纪古地理环境演变与“豫灵人”出现之间有着紧密相关关系的一些看法和认识。     

Seismic analysis of semi-sine shaped alluvial hills above subsurface circular cavity

In this study, a seismic analysis of semi-sine shaped alluvial hills above a circular underground cavity subjected to propagating oblique SH-waves using the half-plane time domain boundary element method (BEM) was carried out. By dividing the problem into a pitted half-plane and an upper closed domain as an alluvial hill and applying continuity/boundary conditions at the interface, coupled equations were constructed and ultimately, the problem was solved step-by-step in the time domain to obtain the boundary values. After solving some verification examples, a semi-sine shaped alluvial hill located on an underground circular cavity was successfully analyzed to determine the amplification ratio of the hill surface. For sensitivity analysis, the effects of the impedance factor and shape ratio of the hill were also considered. The ground surface responses are illustrated as three-dimensional graphs in the time and frequency domains. The results show that the material properties of the hill and their heterogeneity with the underlying half-space had a significant effect on the surface response.

     

Time-history responses on the surface by regularly distributed enormous embedded cavities:Incident SH-waves

The time-history responses of the surface were obtained for a linear elastic half-plane including regularly distributed enormous embedded circular cavities subjected to propagating obliquely incident plane SH-waves. An advanced numerical approach named half-plane time-domain boundary element method(BEM), which only located the meshes around the cavities, was used to create the model. By establishing the modified boundary integral equation(BIE)independently for each cavity and forming the matrices, the final coupled equation was solved step-by-step in the timedomain to obtain the boundary values. The responses were developed for a half-plane with 512 cavities. The amplification patterns were also obtained to illustrate the frequencydomain responses for some cases. According to the results,the presence of enormous cavities affects the scattering and diffraction of the waves arrived to the surface. The introduced method can be recommended for geotechnical/mechanical engineers to model structures in the fields of earthquake engineering and composite materials.     

Discovery and Analysis of the Fossilised Yuling-Man Skull

A fossilised paleoanthropological skull was discovered in November 1987, in the guily-head cliff on the east bank of Wenyu River near Xinza village, Yuling - town (hence the name Yuling-Man), Lingbao country, Henan Province, China. The skull, dated to an absolute U-isotope (U234 to U238 ) age of B. P. 156000 ± 13000 years, was found in the upper portion of the alluvial statum of the mid-Pleistocens Series, together with pateoliths of the Kehe Cutture System in the mid-late Paleolithic Periods. Although much research has been nomied out in this area, this is the first fossilised paleoanthropological skull in have been found. Therefore, this project, funded by the Natural Science Foundation/Henan Scientific Committee, is making new contributions to paleoanthropological research in China.