自贡盐业铁工具的防锈保护

通过对馆藏盐业铁工具的锈层性状及结构的检测分析,并结合当地环境气候特征,认为其继续锈蚀的机制是电化学循环机制,提出除去有害锈、涂料封护的CLFJ防锈法。CLFJ防锈法处理生成的表面膜经防锈性检测,耐CuSO_4滴液、耐盐水性及耐水性指标全部合格,经模拟自然暴露3年条件下工业大气浸蚀的加速实验表明,馆藏条件下防锈时效性指标达5年以上;同时,表面膜呈现出贴近原貌的铁锈色。     

应县木塔结构监测与试验分析研究综述

应县木塔历史悠久,结构复杂,其主要结构构件及构造做法基本上保留了原建时期的面貌,是研究我国早期古代建筑技术及大木制度的重要实物遗存,具有独特的艺术价值和极高的科学价值和成就。然而,由于年久失修。再加上民国时期的错误修缮和战争年代的炮弹袭击以及后来多次地震的损伤累积,当前,应县木塔二层明层结构倾斜变形严重,底部三层结构病害缠身,结构亟须修缮加固。近80年来,国内数十家单位参与应县木塔保护和研究工作,取得一些成果,为制定应县木塔保护方案提供了理论依据和基础数据。本文围绕应县木塔结构试验、结构计算及结构监测等几个方面的工作,梳理和归纳了应县木塔结构监测与试验分析的研究现状,并提出现存问题和建议,供相关研究和技术人员参考。     

Experimental Investigation on the Seismic Behavior of the Semi-Rigid One-Way Straight Mortise-Tenon Joint of a Historical Timber Building

ABSTRACT

This article aims to disclose that the deformation and damages of the one-way straight mortise-tenon (OWSMT) joint, the key force transmission connection of traditional wood buildings, lead to a significant reduction in structural safety of ancient timber structure. For this purpose, the damage of mortise joint in practical engineering wassimulated by controlling the gap and width between mortise and tenon. A total of 23 groups of scaled 1:2 OWSMT joint specimens were fabricated and tested subjected to cyclic loadings, and the hysteretic curves of OWSMT joint with different damage degrees were obtained. Through skeleton curves, stiffness degradation curves, and equivalent viscous damping curves of the OWSMT joint, the seismic performance of damaged wood joints was quantitatively analyzed. The results show that, with the increase in the gap between the tenon and the mortise, the slip between them became increasingly obvious, the fullness and peak of the hysteresis curve gradually decreased, the gradient of the skeleton curve also dropped, and both the stiffness degradation curve and the equivalent viscous damping curve are gradually reduced. The research findings shed new light on the seismic assessment of aging timber buildings.     

Structural Assessment of Ancient Masonries before and during a Rehabilitation Process

ABSTRACT

The rehabilitation of old buildings requires detailed knowledge of the mechanical characteristics and stress state of the structural elements, which play an important role in the intervention process. In this sense, non-slightly destructive tests can estimate structural characteristics with good precision at relatively low costs. Consequently, this article presents a device, based on the flat jack technique, applied to continuous stress monitoring over time. It also focuses on the onsite determination of service stresses and its continuous monitoring in several masonry buttresses of a historic building, as well as the assessment of the structural safety before, during, and after an intervention process. A brief analysis of the research is performed, and the motivation and the methodology adopted are described. Finally, the evolution of the measurements recorded and the analysis of the results achieved are detailed. The study enabled recommendations to be made to the intervening agents that guarantee structural safety.     

红茶菌发酵液清洗丝织文物表面结晶盐的应用研究

在我国考古出土的丝织品数量多,种类丰富,但由于墓葬环境的特殊性,如棺液的浸泡等原因,丝织文物的表面形成很多结块,影响了文物的品质。因此,对此类丝织文物的清洗成为文物保护工作的重要一环。为此,本研究以唐代出土丝织文物残片表面的结块为研究对象,利用拉曼光谱和X射线衍射仪检测技术对其表面结块的成分进行分析。结果表明,结晶盐的主要成分为CaSO4.2H2O。本研究针对其结晶盐的成分,再利用显微观察、抗拉强度检测等手段分析了红茶菌发酵液对老化的现代蚕丝影响。在得出没有损伤的基础上,利用红茶菌发酵液中的生物有机酸和生物酶作为生物清洗剂清洗唐代丝织文物残片表面的结晶盐,取得了良好的清洗效果,对丝织文物本身无损伤。     

Sonic Tomography for Masonry Walls Characterization

ABSTRACT

Nowadays, Sonic Pulse Velocity tests (SPV tests) are widely applied for detecting the morphology, hidden defects, and voids within structural elements. This technique, largely applied because non invasive and easy to perform, reveals particularly adapt in the case of ancient buildings, where usually any damage is not tolerated due to the historical preservation requirements. Moreover, recently the SPV tests have been also applied with tomography technology to obtain images of sonic speeds from which it is possible to rapidly reconstruct the internal elements morphology.

In this article, the results of some SPV tomographies regarding masonry elements are presented. The tests are carried out with the aim of establishing consistency and accuracy of this technique in determining the morphology of the investigated elements. The influence of investigation points number and noise smoothing is taken into account, too. At first, the results of a tomography derived from synthetic data of an ideal section are shown. Then, the SPV tomographies of some masonry specimens and of elements sections of a real case study are illustrated and compared among them.     

制备方法对土遗址重塑样稳定性的影响研究

土建筑遗址本体的保护受遗址土的物理、水理、力学及所处环境差异的影响，重塑样是替代土遗址测试其各种性质的重要手段，重塑样拌制土性质的稳定性是科学评价、对比分析试验研究的基础和前提。本研究基于不同拌制土的方法，通过观察、拍照、量取土团粒大小以及同条件制备样品的无侧限抗压强度等，综合评价不同拌制土方法的影响条件。研究发现，采用人工拌土、闷土时间在24 h的土所制的试样最具稳定性，随着闷土时间再增加，土样强度在逐渐降低。本研究为土建筑遗址室内试验研究和工程现场拌制土料提供理论参考和技术支撑。