Dynamic Interaction between Rigid Foundations on Multi-layered Stratum

This article concerns the cross-interaction problem among multi-foundations on a linearly viscoelastic medium at very small shear strains. In the analysis, the foundations are discretized into a number of sub square-elements. The dynamic response within each sub-element is described by the Green’s function, which is obtained by the Fourier-Bessel transform and the precise integration method. Incorporating the displacement boundary condition and the force equilibrium of the foundations, it obtains the dynamic impedance and compliance functions of the foundations. Extensive results for two rigid circular foundations placed at different separations are presented. Parametric studies are carried out on the dynamic interaction among adjacent foundations. Illustrative results for several closely spaced foundations are also illustrated.     

IBEM for Impedance Functions of an Embedded Strip Foundation in a Multi-Layered Transversely Isotropic Half-Space

An indirect boundary element method (IBEM) is developed to study the dynamic impedance functions (stiffness coefficients) of a rigid strip foundation embedded in a multi-layered viscoelastic transversely isotropic (TI) half-space. The proposed IBEM using half-space Green’s functions of distributed loads as fundamental solutions have the merits of fictitious loads being directly applied on the real boundaries without the problem of singularity and of the discretization effort restricted to local boundaries. In addition, the accuracy of the proposed method is not affected by the thickness of the discrete TI layers, as the exact dynamic stiffness matrix is employed. The presented algorithm is verified via comparisons with published results for the isotropic medium. By taking a rigid strip foundation embedded in a homogeneous half-space, a single-layered half-space, and a multi-layered half-space as examples, the effects of material anisotropy, frequency of excitation, and soil layer on the impedance functions are studied in detail. Numerical results show that impedance functions for the TI medium can be significantly different from those of the isotropic case. The variation of TI parameters alters the dynamic characteristics of the TI layered site, which in turn alters the dynamic interaction between the soil and foundation. In addition, the soil sedimentary sequence also has a remarkable influence on the impedance functions.     

陕西白水县下河遗址仰韶文化房址发掘简报

2010年,陕西省考古研究院对白水县下河遗址进行了发掘,主要收获为三座大型房址。三座房址均为五边形,有内、外两层墙体,使用料礓石烧制的白灰铺设地面。房址内出土遗物以陶器为主,另有石器、骨器和蚌器。这三座房址的发掘,对研究仰韶时期的建筑技术以及该遗址的聚落、经济等具有重要意义。     

图们江地区开发与建设大陆桥的走行路线研究

建设一条新亚欧大陆桥与图们江地区开发是互为因果的两项工程。对国际物流的分析是建设大陆桥的根据之一。本文从物流分析入手探讨建设大陆桥的必要性,随后又对照已有大陆桥情况提出对新大陆桥走行路线的认识。     

陕西白水县下河遗址大型房址的几个问题

下河遗址大型房址F1、F2、F3均为半地穴式五边形建筑,年代为庙底沟文化时期。这种大型建筑是我国宫殿建筑的滥觞。房屋的营建大致包括六道程序,房内的地面均为料姜石制成的白灰铺设。F1为目前所见同期房址中最大者,对认识下河遗址庙底沟文化时期聚落的组织管理和资源调度等具有重要意义。     

Resistivity Tomography Imaging of the Substratum of the Bedestan Monumental Complex at Nicosia,Cyprus

In the framework of the EU–UNDP project ‘Rehabilitation of Old Nicosia’ (Cyprus, 2004–9), a high‐resolution geoelectrical survey has been performed inside the partially ruined monumental complex of St Nicholas of the English, now called the Bedestan, which was designed to become a venue space for cultural activities. The aim was to detect buried traces of a Byzantine basilica of the sixth century, on the ruins of which, according to tradition, the construction of St Nicholas was begun in the 12th century. The survey has been conducted on the floor of the monument, using a dipole–dipole electrode array along two perpendicular sets of profiles. In order to model the resistivity distribution, the probability‐based electrical resistivity tomography inversion (PERTI) method has been applied. Sets of aligned blocks with resistivity in the range 100–400 ohm·m, bounding a three‐room rectangular space, and traces of a rounded structure with mean resistivity about 150 ohm·m, appearing at one extremity of the central room, are the main resistive features recognized down to 4 m depth, within a conductive background with resistivity in the range 20–40 ohm·m. Altogether, these resistive features, showing in plan the shape of a church characterized by a central nave with an apse and two side aisles, have been interpreted as an evidence of the existence of remains of the earlier Byzantine basilica. Moreover, small volumes with resistivity in the range 10–12.6 ohm·m have been found, scattered underneath the whole surveyed area. Taking into account the PERTI results, ground‐truth has been performed in two sites, designed to become two permanent protected exposures of the archaeological findings beneath the floor of the newly restored Bedestan. At one site, excavations detected remains of masonry in correspondence of the alignment of resistive blocks at the left margin of the left side aisle of the churchlike structure. At the other site, graves, entirely filled with wet debris in an alluvial soil matrix, have, instead, been found in correspondence with the greatest conductive volume, detected outside the perimeter of the churchlike structure. Both findings have been dated back to the sixth century. Since the Bedestan case‐history is one of the first applications of the PERTI algorithm to real field data sets, its performance has been tested using the well‐known ERTLab^TM commercial software as benchmark. The comparison has shown a general consistency between the two inversions, and also confirmed the much higher computing speed, better filtering capacity and greater versatility of the PERTI algorithm, already outlined in a previous paper where only synthetic models were tested.