通古斯巴西古城遗址土体特性及PS加固试验

通古斯巴西古城遗址是新疆重要的土遗址之一,原为唐龟兹驻兵的安西都护府所在地。遗址中曾出土大批文物,对于研究西域的屯垦历史和古代城址布局等有重大意义。为了系统地研究了通古斯巴西古城遗址土的工程特性,在实地调查的基础上,通过室内试验对通古斯巴西古城遗址土的物理、力学、水理和化学性能进行测试。此外,还测定了不同PS浓度加固后遗址土重塑土块抵抗风蚀雨蚀能力的差异,进一步确定了PS的渗透加固措施对土质文物的防风化及雨蚀效果。结果表明,7%的PS溶液防风化抗雨蚀效果要更为显著。研究结果可为PS的施工应用提供依据。     

Soil mark studies near Winchester,Hampshire

The fate of artifacts incorporated into the ploughsoil as a result of plough damage is considered in terms of two soil mark sites near Winchester, Hampshire. Ploughsoil and subsoil analyses indicate that dispersal of soil material, as a result of ploughing, is limited at the present time and under mould board ploughing techniques. The origin of soil marks underlain only by bedrock is also considered and evidence indicates that such soil marks may appear as groundsurface expressions of ditches which have been removed by plough damage where dispersal of ploughsoil is minimal. Such soil marks may be only short lived if plough depth continues to increase.     

The decomposition of starch grains in soils: implications for archaeological residue analyses

Recent research involving starch grains recovered from archaeological contexts has highlighted the need for a review of the mechanisms and consequences of starch degradation specifically relevant to archaeology. This paper presents a review of the plant physiological and soil biochemical literature pertinent to the archaeological investigation of starch grains found as residues on artefacts and in archaeological sediments. Preservative and destructive factors affecting starch survival, including enzymes, clays, metals and soil properties, as well as differential degradation of starches of varying sizes and amylose content, were considered. The synthesis and character of chloroplast-formed ‘transitory’ starch grains, and the differentiation of these from ‘storage’ starches formed in tubers and seeds were also addressed. Findings of the review include the higher susceptibility of small starch grains to biotic degradation, and that protective mechanisms are provided to starch by both soil aggregates and artefact surfaces. These findings suggest that current reasoning which equates higher numbers of starch grains on an artefact than in associated sediments with the use of the artefact for processing starchy plants needs to be reconsidered. It is argued that an increased understanding of starch decomposition processes is necessary to accurately reconstruct both archaeological activities involving starchy plants and environmental change investigated through starch analysis.     

Identifying domestic functional areas. Chemical analysis of floor sediments at the Classical-Hellenistic settlement at Düzen Tepe (SW Turkey)

For over a decade, multi-element chemical analysis of floor sediments in archaeological contexts has been a tool to identify and interpret anthropogenic chemical residues and activities. For the current study, a multi-element chemical analysis was applied to floor samples from a Classical-Hellenistic courtyard building at Düzen Tepe (SW Turkey). Among a series of 19 elements analyzed, K, Mg, Fe, P and Sr are thought to directly reflect anthropogenic chemical residues. The elements Cr, Mg, Ni, Pb and Ti are considered to reflect the geological background of the site, yet their contents seem to vary over different chemical residue zones, making them a suitable tool for delineating activity areas. Overall, the sampling and analysis techniques applied at Düzen Tepe – mild acid sample extraction and ICP-OES analysis – have proven to be fit for this kind of study. The analyses allow human activity zones within the study area to be identified and interpreted and deliver insights into the archaeological contexts that could not be obtained by archaeological research alone.     

腹土寄生物考古研究方法的探索和实践

前言寄生物考古学是近30年来兴起的一门科技考古的分支学科,它以考古中发现的寄生虫遗存为研究对象,通过还原古代寄生虫感染的流行分布,结合其他考古信息,了解当时影响寄生虫感染的各种因素,如人群交流、迁徙、水资源、生业模式、社会阶层、自然环境、医药卫生等等,考察古人或与人相关     

广州增城墨依山玉器材质和受沁过程分析

为综合研究出土玉器的风化机理,正确评估玉器的保存状况,本研究采用物相、成分和电镜等方法对2016年广州重要考古发现——增城墨依山玉器进行了材质和结构分析,确认了墨依山玉器材质为透闪石。在此基础上,对玉器周边土壤进行了物相、成分、结构和酸碱度等分析,并结合玉器本体和遗址气候条件,综合探讨了强酸性环境下墨依山玉器的受沁过程。本研究有助于丰富对玉器风化机理的认识,有利于科学制定玉器的保护措施。     

Liquefaction-Induced Lateral Load on Pile in a Medium Dr Sand Layer

One-g shake-table experiments are conducted to explore the response of single piles due to liquefaction-induced lateral soil flow. The piles are embedded in saturated Medium Relative Density (Dr) sand strata 1.7–5.0 m in thickness. Peak lateral pile displacements and bending moments are recorded and analyzed by uniform and triangular pressure distributions. On this basis, the observed levels of pile bending moment upon liquefaction suggest a hydrostatic lateral pressure approximately equal to that due to the total overburden stress. Using the experimental data, comparisons with current recommendations are made, and the Showa Bridge case history is briefly assessed.     

General Seismic Load Distribution for Optimum Performance-Based Design of Shear-Buildings

An optimization method based on uniform damage distribution is used to find optimum design load distribution for seismic design of regular and irregular shear-buildings to achieve minimum structural damage. By using 75 synthetic spectrum-compatible earthquakes, optimum design load distributions are obtained for different performance targets, dynamic characteristics, and site soil classifications. For the same structural weight, optimum designed buildings experience up to 40% less global damage compared to code-based designed buildings. A new general load distribution equation is presented for optimum performance-based seismic design of structures which leads to a more efficient use of structural materials and better seismic performance.     

Behavior of Gravity Type Retaining Wall under Earthquake Load with Generalized Backfill

Dynamic response of gravity type retaining wall under seismic load is a topic of considerable research for the last 90 years or more. The concept of deriving dynamic pressure based on rigid body mechanics as proposed by Mononobe and Okabe (M-O method) in 1929 continues to dominate the majority of the codes around the world, although it is reported in a number of cases that the M-O method underestimates the response in many cases. Although the M-O method was originally derived for cohesion less soil yet it is used frequently in deriving pressure for other general soil conditions also, like c-φ soil, c-φ soil with surcharge, etc.

This article is an attempt to predict the response of a gravity wall having a generalized backfill (i.e., c-φ soil with surcharge q and that could also be partially saturated) considering its structural deformation as well as the effect of dynamic soil structure interaction (DSSI), a phenomenon which is often ignored in practice. The results are finally compared with a 2-D finite element analysis carried out in ANSYS to check its validity.     

Considering Soil-Nonlinearity Effect on Seismic Performance Evaluation of Structures based on Pushover Analysis

According to the most of current seismic codes, nonlinear soil behavior is commonly ignored in seismic evaluation procedure of the structures. To contribute on this matter, a pushover analysis method incorporating the probabilistic seismic hazard analysis (PSHA) is proposed to evaluate the effect of nonlinear soil response on seismic performance of a structure. The PSHA outcomes considering soil nonlinearity effect is involved in the analysis procedures by modifying the site-specific response spectrum. Results showed that incorporation of nonlinear soil behavior leads to an increase in displacement demand of structures which should accurately be considered in seismic design/assessment procedure. Results of implemented procedure are confirmed with the estimated displacement demand including soil-structure interaction (SSI).