A SUMMARY OF RESULTS OF SIMULATED SEISMIC LOAD TESTS ON REINFORCED CONCRETE BEAM-COLUMN JOINTS,BEAMS AND COLUMNS WITH SUBSTANDARD REINFORCING DETAILS

The results of some simulated seismic load tests on reinforced concrete one-way interior and exterior beam-column joints with substandard reinforcing details typical of buildings constructed in New Zealand before the 1970s are described. The tests were conducted using both deformed and plain round longitudinal reinforcement. The interior beam-column joint cores lacked transverse reinforcement and the longitudinal bars passing through the joint core were poorly anchored. The exterior beam-column joint units contained very little transverse reinforcement in the members and in the joint core. In one exterior beam-column joint unit the beam bar hooks were not bent into the joint core. That is, the hooks at the ends of the top bars were bent up and the hooks at the ends of the bottom bars were bent down. This anchorage detail was common in many older buildings constructed before the 1970s. In the other exterior beam-column joint unit the hooks at the ends of the bars were bent into the joint core as in current practice. The improvement in performance of the joint with beam bars anchored according to current practice is demonstrated. In addition, tests were conducted on interior joints with lap splices in the beam longitudinal reinforcement bars near the column face. The tests were conducted using both deformed and plain round longitudinal reinforcement. Tests were also conducted on columns with plain round bar longitudinal reinforcement and inadequate transverse reinforcement.

The reinforcing details were close to identical to those in an existing seven storey reinforced concrete building that was designed and built in New Zealand in the late 1950s.

The test results give an indication of the performance of beam-column joints and members with the above now out-of-date reinforcing details.

The test results reported are a summary of results reported in a number of publications written since 1994.     

SEISMIC DESIGN OF BASE-ISOLATED STRUCTURES USING CONSTANT STRENGTH SPECTRA

This paper presents the concept of constant strength design spectra for the design of base-isolated structures; particularly those structures using isolators with a bilinear hys-teretic behaviour when subjected to dynamic loading. The constant strength design spectra relate peak accelerations, velocities, displacements and effective isolated natural periods for bilinear systems with a given yield strength and post yield stiffness. Constant strength design spectra could be useful for the design of base isolators with bilinear hysteretic behaviour, as these devices can be designed for fixed yield strength and post yield stiffness. The concept of constant strength design spectra and its application for the design of base isolated structures is illustrated with case studies of specific structures.     

RESPONSE OF UNREINFORCED MASONRY BUILDINGS

Abstract

A summary of dynamic measurements are presented that illustrate relations between linear seismic demand and true nonlinear response of unreinforced masonry buildings with flexible diaphragms and rocking piers subjected to a series of simulated earthquake motions.     

新型防霉剂CM1在丝织品保护中的应用研究

为探讨新型防霉剂CM-1在丝织品保护中的效果,通过抑菌活性和模拟环境加速老化实验,检验了其用于丝织品保护中的生物活性,皿内抑菌实验表明防霉剂有很好的生物活性,且具广谱性。结合多种仪器分析,通过热老化、光老化、酸碱水解老化等方法验证防霉剂对丝织品后期安全性影响。结果表明,防霉剂能有效抑制丝织品褪色,红外光谱显示样品的化学结构没有变化,扫描电镜结果说明防霉剂可使样品对抗热老化,对样品表面有保护作用,拉力试验和X-射线衍射论证了防霉剂对丝织品的拉力强度和结晶度均没有影响。     

Bison Bone Fragmentation and Survivorship: a Comparative Method

Zooarchaeologists usually describe a bone fragment as a particular portion or segment using terminology based on skeletal orientation (e.g. proximal, anterior, lateral). A more precise understanding of bone fragmentation can be achieved by naming portions for discrete anatomical features and defined zones. Since the anatomical features are the diagnostic criteria for identifying and orienting bones, each specimen normally has at least one such portion, and a complete element contains all of them. This recording method facilitates study of the relationship between survivorship and volume density, and it enhances inter-site comparisons. The method employs the minimum number of elements (MNE) and minimum animal units (MAU) across a site-wide aggregate. Although illustrated here with an analysis of bison bones, the method can be adapted for the study of other taxa as well as for inter-species comparisons.     

Studies on amerindian dogs, 1: Carbon isotopes in relation to maize in the diet of domestic dogs from early Peru and Ecuador

Work initiated purely as a dating project in support of a craniometric and morphological investigation of domestic dogs from early Peru has proved to have much wider implications. The stable carbon isotoperatios (¹³C/¹²C) of hair samples from ten dogs show that maize formed a significant part of their diet. Radiocarbon dates for these remains have confirmed that they belong to the period well after the cultivation of maize was first established. Stable carbon isotope measurements can thus be used to test for the presence of maize as a dietary constituent at earlier sites even where there is otherwise only indirect evidence for its cultivation. Collagen from animal or human bone is a suitable alternative to hair for this purpose and the method has been successfully applied to collagen dating to c. 3000 BC from the Valdivia culture site of Real Alto, Ecuador, as well as to a series of early Peruvian dogs.     

The survival of biochemical information in archaeological bone

The paper gives a review of the advantages of genetic information potentially available from surviving molecules (especially proteins) in bone. Survival of such information depends on degradative processes during burial. Conventional protein chemical and immunochemical investigations on various organic components remaining in buried archaeological bone are described. The results provide information on the chemistry of collagen degradation, and indicate that polymorphic macromolecules survive at too low a concentration to be easily detectable.     

Characterization of pozzolanic lime mortars used as filling material in shaped grooves for restoring member connections in ancient monuments

This article presents a set of mechanical characteristics for a pozzolanic mortar consisting of hydrated lime and metakaolin, which is used as filler between metallic connectors and marble blocks during restoration activities of ancient monuments in Greece. Mechanical properties include the uniaxial and triaxial compressive strength, the indirect tensile strength, the bending strength, the elastic modulus and Poisson’s ratio, and a shear failure criterion. Cored cylindrical specimens are used for determining the uniaxial and triaxial compressive behavior and the indirect tensile strength of the mortar, thus ensuring the repeatability of the experimental results. The triaxial tests indicated a plastic behavior of the mortars under study, enabling them to perform well in conditions of high shear forces. Calcite and hydraulic components formed in the setting procedure contributed to the plasticity of the final mortar. The mechanical properties that were developed can be utilized to model material behavior and failure under conditions of confined or triaxial loading. The development of a shear failure criterion for a pozzolanic mortar is a substantial accomplishment that has not been previously reported in the international literature.     

Caribou metapodial shaft splinter technology

A technique for the extraction of long narrow bone splinters for the production of bone artifacts is reported. Caribou metapodial bones from the Paxson Lake site, central Alaska, were modified by striking behind the lateral and medial borders of the posterior surface using a percussion method. The resulting fragments are termed shaft splinter cores and shaft splinters. The long shaft splinters may have been used for producing a variety of bone implements.     

骨角质文物保护研究进展

骨角质文物丰富的历史价值使其成为世界各地考古学、人类学、艺术史研究的重要材料,但由于骨角质文物一般年代久远、保存环境各异以及自然矿化等因素造成该类文物的保存状况不容乐观。该文拟从骨角质文物保护研究的角度,对目前骨角质文物的制作材料与工艺、病害研究、修复技术及预防性保护等方面进行梳理,并尝试找出目前存在的问题与保护需求。我国骨角质文物保护需求主要包括出土饱水器物的现场保护是骨角质文物保护中亟待解决的问题;中国最早的古文字资料即有字甲骨的防风化研究是骨角质文物保护中的重点课题;全国各地出土的不同时期动物骨骼的保护是骨角质文物保护工作的主要内容。