Abstract:In order to scientifically preserve two culturally important imperial stelae, specifically, the north stela and the south stela in Jinling Dabaoen Temple, first the structural performance of these stelae were analyzed by using ANSYS , a type of engineering simulation software. The structural safety issues were investigated under normal conditions and under earthquake conditions. Based on simulation results, a conservation plan is laid out. Adding isolation bearings under the stelae is suggested. The structural performances of the two stelae after adding the isolation bearings were also analyzed by ANSYS. The results showed that the first natural frequency of the north stela (i.e., the imperial stela) was 0.087 times of that of the south stela (lacking the royal stela). Under the earthquake conditions, the imperial stela on the northern site was most likely to be damaged. In the case of the southern stela, the tortoise head was most likely to be damaged first. After installation of bearings, the natural frequencies and the maximum tension and compression stresses of the two stela decreased significantly and became immune to damage even in a seventh degree earthquake. The study provides information about the structural analysis and conservation of stelae.

Abstract:The necessity to protect cultural heritage sites has a big impact on the planning of metro lines, such as routes and depths of tunnels. A prediction model is needed to see how trafficinduced vibration can affect relics and what can be done to prevent damage. In this article, it is assumed that a subway line is proposed for a historical city, and then a model based on real vibration data collected from Xi'an and Chengdu subway systems is established. The mechanical parameters of the soil were considered and a vibration response model of relics, both above and below ground, was established under various conditions. The results were evaluated based on national standards. These studies provided information in regard to the design of subway routes and tunnel depths. In summary, these studies showed that ground vibration decreases as tunnel depth increases and it increases as the train speed increases. When the train speed is 80 km/h, the tunnel (top) depth should be 15 m to meet the vibration control standards of the National Protection Unit. These results provide a reference for consideration of traffic induced vibration and relics security.

Abstract:The growth and decay of plant root systems can have destructive effects on earthen heritage sites, challenging permanent conservation of those precious sites. In this study, ground penetrating radar was used to detect the root systems of Populus gansuensis in ruins of the Ming Dynasty Great Wall of Gaotai, Gansu province. The results showed that the plant root systems of P. gansuensis distributed mainly in the north side of the ruins, extending from south to north. The lateral roots distributed around the plant taproot. The plant root systems of P. gansuensis distributed mainly at a the depth of 35~85 cm. The diameter of the taproot is about 12cm. The maximum measurable depth that the 400MHz antenna could reach was 200 cm below the surface. However, the detection precision of a 900MHz antenna is much greater than that of a 400 MHz antenna. If both were used, more information could be obtained on the growth status and the range of distribution of plant root systems. For the first time, threedimensional images of the root system were provided by the portable ground penetrating radar technology. Furthermore, the depth and location of the underground root system can be confirmed in a nondestructive way. This technology provides important scientific information for the protection and consolidation of the Great Wall site.

Abstract:In order to protect relics and send out warnings of damage due to landslides, a monitoring system using a high accuracy Global Positioning System (GPS) and a telemetry remote terminal unit (RTU) has been set up to monitor the physical conditions of mausoleum slope by wireless communication. The system can be used to monitor both the internal environment burial mound and landslide conditions. The monitoring parameters and alarm signals will be transmitted to the control centre in realtime through general packet radio service (GPRS),then displayed continuously on the managed software platform. The security personnel can then respond immediately based on the information obtained. The system represents an efficient way to protect heritage sites and tombs of various sizes.

Abstract:The soluble salts that cause damage to mural paintings in the Mogao grottoes are usually sodium chloride (NaCl) and sodium sulfate (Na₂SO₄). Of the destructive forces, the crystallization of sodium sulfate is the worst. This article focuses on how sodium sulfate damages the glutenite and ground layers under different temperature conditions and multiple wetdry cycles. Sodium sulfate has a great ability to penetrate, migrate and crystallize, causing serious damage. The crystallization mechanism of sodium sulfate and the appearance of damage caused by it are quite different from those of sodium chloride. Expansion and erosion are accelerated by increased sodium sulfate concentrations and certain wetdry cycle times. Among various meteorological conditions, a drywet cycle above 40% humidity and the temperature changes below 32.4 ℃ accelerated the damage. Salt expansion test block strength tests show that the intensity of damage caused by salt crystallization is very large. Typical damage characteristics are formation of powders and granular peeling. The work aimed to explore theories aimed at murals protection.

Abstract:Composite bolts containing steel bars have been successfully applied for the anchorage of earthen sites. However, the mechanism of anchoring has not been studied yet. In the Jiaohe ruins (a typical earthen site), composite bolts containing 20mm diameter steel bars were chosen for pullout experiments and to monitor the interface strain along the bolt. The experimental results indicate:1) the maximum anchoring force of a 3m long bolt is over 150kN, and the bolt shows strong plastic deformation; 2) at the damage interface, the axial strain of the interface between steel and composite material is greater than at others; 3) due to the heterogeneity of the bolt, the irregularity of the axial strain occurs at the interface between bamboo and composite materials, which creates some local compression phenomena; 4) the change of shear strain along the bamboogrout interface and the bamboocomposite material interface coincides with that of the pullout load, and shear strain is transferred to the end of the bolt under higher loads; 5) because of the multilayer structure of the bolt, transverse transfer and shearing expansion appear distinctly during the pullout experiment.

Abstract:To effectively protect the Forbidden City's Taihe Palace, its dynamic characteristics and seismic responses to frequently occurring earthquakes were studied by finite element analysis methods. Based on hypotheses that tenonmortise joints and bracket sets were simulated by spring elements, and that column roots were of swivel restriction, a finite element model of Taihe Palace was built. By modal analysis, the basic frequency and main modes of the palace were obtained; from timehistory analysis, displacement and acceleration response curves of typical nodes, and internal force response curves of typical elements were obtained. Analysis shows that basic frequency of Taihe Palace is 0.9 Hz and that its main modes are of translation. During frequently occurring earthquakes, the structure vibrates steadily, although its peak displacement as well as internal force response values are within permitted limits. From this, it can be concluded that tenonmortise joints and bracket sets are helpful for seismic mitigation of of damage to the structure.

Abstract:In order to accurately grasp the relationship between damaged wooden frame nodes and their mechanical properties and to provide a foundation for evaluating the overall safety of a structure, a reduced scale, single room architectural model in a 1:2 ratio was built according to Qing Dynasty construction codes in magnificent building size. The dovetails of the model building were of four different degrees of off the tongue. Through vertical loading tests, the main forms of node damage and ultimate load bearing capacity were recorded and analyzed. The experimental data and conclusions can be used as reference for researchers doing similar structural analysis.

Abstract:A wellpreserved late Warring States period tomb unearthed in Yiyuan, Shandong Province contained a great number of burial accessories. Among these burial accessories were found leather objects. The discovery of archaeological leather is rare in archaeological excavations in the North of China. Those objects are important for the study of ancient northern region leather tanning procedures. The archaeological leather samples were studied by using the attenuated total reflection Fourier transform infrared spectroscopy (ATRFTIR) and scanning electron microscope (SEM) to obtain insight into the functional groups and pattern of collagen fibrils of the waterlogged Warring States period leather. For comparison, modern sheep leather samples were analyzed using the same approach. The ATRFTIR comparisons of the archaeological leather and modern leather showed that the archaeological leather contained the characteristic absorption bands of the leather. The SEM studies indicated that the pattern of collagen fibrils of the waterlogged leather was similar to that of modern sheep leather. This study provides a reference for identification of the archaeological leather.

Abstract:Due to the marine climate and the soil environment of the Shenzhen area, the bronzes in the ancient tombs of Tiezaishan seriously corroded. In order to provide the scientific information for further conservation, the degree of corrosion of these unearthed bronzes was studied. Silver nitrate analysis, Xray fluorescence spectroscopy and Raman spectroscopy were employed to study the patinas on these bronzes. The results show that the main composition of patinas is malachite (CuCO₃·Cu(OH)₂). Sampleite (NaCaCu₅(PO₄)₄Cl·5H₂O) is also discovered on one bronze, which is rare in bronzes buried in moist soil environments. Moreover, nanocrystalline SnO₂ was found on the other bronze. This analysis provides experimental information relevant for the conservation of these bronzes, and also may be a useful reference for the conservation of other bronzes buried in Shenzhen area.

Abstract:This paper is mainly concerned with the impact of restoration putty materials used on iron relics. Commonly used putty materials were tested using dampheat aging, saturated acidic water vapor corrosion and a xenon lamp light aging test. The results show that different putty materials show different amounts of iron corrosion. The applicability of putty could be rated on the basis of its degree of corrosion of iron. Based on two aging test rounds, this work shows that lime is more suitable for the conservation and restoration of iron relics.

Abstract:Miniature handheld digital optical microscopy, microenergy dispersive Xray fluorescence (EDXRF) spectroscopy and Xray diffraction (XRD) were used to systematically analyze ceramic samples from the Guangdong folk art museum in order to understand their manufacturing technique. The analysis indicates that the ceramic bodies all have high SiO₂ and low Al₂O₃ contents. The bodies also have a high content of Fe₂O₃. The glaze belongs to hightemperature calcium type. Wood ashes are likely to have been used as a flux in the samples. ZnO was found in the glaze. In the middle and later periods of the Qing Dynasty, the firing temperature of the ceramics was higher than 1100℃, and in the Republic of China period the firing temperature was even higher than 1200℃. These analytical results provide useful information regarding the manufacture of decorative ridge ceramic figurines from Shiwan, Guangdong Province.

Abstract:This study was aimed at optimizing cleaning parameters of water on paper relics. Different types of water, including ultrapure water, pure water, distilled water, tap water and hard water were used to see how they affect paper pH number, tensile strength, color, degree of whiteness and degree of polymerization of paper under various cleaning cycles and temperature. The results show that hard water and tap water are poor because the whiteness level increased only by 2.0 levels after cleaning. The tensile strength of treated paper dropped 17%~24%. With ultrapure, pure and distilled water the degree of whiteness increased by levels of 2.99,2.41 and 2.77 respectively; while the tensile strength of those cleaned papers decreased by 16%, 9% and 12%. Therefore, ultrapure, pure and distilled waters are suitable for cleaning paper relics. The optimal condition for cleaning in six cleanings was under room temperature. The results can be used as a reference for cleaning paper relics.

Abstract:SanPu” software for cultural property databases is capable of retaining complete and integrating information about relics. However, it is inconvenient for daily usage. This article will show a case study, using FileMaker, to customize the cultural properties database. The goal is to improve the interface and flexibility, to make it easy to share information on mobile devices, to enhance the utilization of cultural property resources, and to give museum curators and researchers an option for building their own databases. A customized database can be more effective with limited budgets.

Abstract:To assess the behavior of visitors, the museum uses radio frequency identification (RFID) to detect and record mobile information about visitors. The paper explains the application of RFID through analysis of mobile information about visitors viewing on an exhibition entitled “Historical Treasures of Lishan Garden” in Emperor Qinshihuang's Mausoleum Site Museum. The feasibility of the RFID application model for research on visitor behavior in the museum was analyzed. The results suggest that RFID could be a powerful tool to analyze the visitor behavior in museums. The method is convenient, accurate and reliable.

Abstract:Selection and evaluation of protective coatings is an important part of heritage conservation. Compared with the traditional accelerated corrosion aging test method, electrochemical impedance spectroscopy (EIS) is qualitative, faster and more accurate, and can be directly used as a nondestructive method for studying cultural relics. This paper introduces the theory, experimental and analytical method of EIS and summarizes its application on metal relics, including bronze, iron and silver objects. The EIS method can be used to select and evaluate protective coatings.

Abstract:Green copper pigments have been widely used over time in artworks and books. As time passes, some copper compounds, such as verdigris, decompose, resulting in corrosion and degradation of papers. The reaction between copper ions and cellulose is a complicated process including oxidation, catalysis, hydrolytic acidification and photochemistry. As a result, treatment and recovery of damaged papers should be based on a good understanding of the mechanism of corrosion and the application of corrosion inhibition methods. For instance, the process of deacidification and decomplexation of metal ions should be understood. This paper reviews related research in this area and summarizes six possible research directions. This review paper can provide ideas and references for researchers specializing in the conservation of paper relics.

Abstract:In the process of the restoration of cultural relics, the first job is to clean the objects. Although currently used methods are effective, they can be polluting, resulting in damage to the human body and to the environment. Finding new cleaning materials and methods is very important for developing sustainable methods for the conservation of relics. The use of dry ice for cleaning cultural relics is the focus of this article. As an experiment, dry ice loaded in an industrial washing machine was used to clean a late Qing Dynasty porcelain object with a thick glaze layer. The results were evaluated. This work showed that dry ice can quickly remove epoxy resin on the porcelain surface without damaging the glaze layer. The whole cleaning process is very environmentally friendly. It produces no pollution and only clean stains without creating any side products. Although the process did not clean epoxy resin laid deep under the surface, this problem could be solved with the development and optimization of the process. Eventually, dry ice cleaning might be an environmental friendly method for cleaning of relics.