Search Results (8)

Facing the challenges of temperature gradient-induced soil cracking and delamination in earthen ruins like Gaochang Ancient City, this study develops a novel phase change microcapsule (MPCM) grouting material designed for dual functionality: structural reinforcement and thermal regulation. We systematically evaluated its performance in both aspects. Experimental results demonstrated excellent thermal cycling stability. For instance, the maximum mass loss was only 0.65% after 200 cycles, indicating its reliability for long-term service. Evaluation showed that the material effectively provides structural strength compatible with the original soil. With 15% MPCM content, the compressive strength reached 1.39 MPa. Simultaneously, it effectively mitigates temperature fluctuations, significantly regulating temperature gradients. The MPCM-15 sample, for example, reduced the heating rate by 9.7 °C/h and peak temperature by 6.0 °C compared to the control group. Field application further validated its effectiveness in both restoring structural integrity by filling cracks and significantly reducing temperature gradient effects within the site. This dual-function MPCM grouting offers a promising new technical approach for the sustainable preservation of earthen cultural heritage. Full article

The design of the enclosure layout is crucial in establishing a comfortable wind environment in Chinese classic landscape gardens. The Ruins Park of the Old Summer Palace exemplifies the mountain construction techniques used in classical Chinese flat gardens, with a diverse and illustrative spatial layout of the hills. In this study, we focused on the earthen hill space of the Old Palace in the Summer Palace Ruins Park. We compared and analyzed the effects of different enclosure layouts of earthen hill spaces on the summer monsoon wind environment. This was achieved via on-site measurements and simulations using computational fluid dynamics (CFD). The results show the following: (1) The direction index of the enclosure layout of the earthen hill space affects wind speed, comfort, and ventilation. Increasing the index reduces speed and comfort but improves ventilation. (2) Increasing the density index of the enclosure layout of the earthen hill space leads to a decrease in wind speed and wind comfort and improved ventilation. (3) Conversely, increasing the area index of the enclosure layout of the earthen hill space results in an increase in wind speed, which can result in better wind comfort but can also lead to poor ventilation. Overall, the results suggest that careful consideration should be given to the enclosure layout of landscape gardens to ensure optimal wind conditions within the space. Full article

Under the action of unidirectional water migration, museum soil sites generally encounter erosion through dry cracking, salt enrichment, etc. In this paper, the earthen site of the Terra Cotta Warriors Museum of the First Emperor of Qin was used as the research object, and the “hydrophobic” property of coated sand was proposed to prevent water migration and salt accumulation. Through the soil column experiment of water salt migration and the HYDRUS software numerical simulation, the water salt migration law of the soil in the heritage site under different conditions and the characteristics of water and salt resistance of plastic-coated sand were studied. The results showed that the salt damage on the earthen ruins was mainly due to the horizontal and vertical migration of water and salt in soil. After embedding the coated sand layer into the soil environment under the earthen site, the vertical and horizontal migration of water and salt in the soil can be completely prevented due to precipitation and groundwater. The coated sand protection technology and method proposed in this paper use materials similar to those of the earthen, and provide a feasible method for the protection of cultural relics in our country. Full article

Natural hydraulic lime soil has good mechanical properties; as an earthen ruin restoration material, its durability is insufficient. Despite natural hydraulic lime being a topic that has been studied for several years from different researchers, it has not yet been fully considered for the improvement of durability. This work aims to experimentally investigate the enhancement of the durability properties of hydraulic lime-based. The performance of natural hydraulic limestone by adding sodium methyl silicate and organic silicon is examined and the effect of adding sodium methyl silicate on its performance and microstructure is studied. The 6%, 10%, and 15% lime–soil comparison test blocks of sodium silicate were compared with different lime–soil comparison test blocks not mixed with sodium methyl silicate; in addition to compression resistance, shear resistance, water absorption, and erosion resistance, dry–wet cycles were carried out, as well as microstructure testing and analysis. The results show that the addition of sodium methyl silicate enhances the compressive strength of hydraulic lime-modified soil, reduces its saturated water absorption, reduces its shear strength, improves its resistance to dry and wet cycles, and forms on the surface of the modified soil particles. The hydrophobic layer further improves its erosion resistance and water resistance. When the sodium methyl silicate content is 0.3%, the natural hydraulic lime soil has good mechanical properties and good durability, which is the optimal ratio. Full article

The newly repaired Kaifeng City Wall has serious cracks, shedding and other issues on the surface, which constitute a significant problem. It is of great significance for the restoration of Kaifeng City Wall to explore the repair materials and techniques suitable for Kaifeng City Wall. The pH, particle gradation, compressive strength and SEM were tested on soil samples with different lime and MgO contents under different slaking times. With the increase of slaking time, the pH value first increased and then decreased. The relationship between pH value and strength showed three stages. The strength of lime-containing soil samples increased first, then decreased and then increased. The MgO content of soil samples showed an opposite trend. The particle gradation was significantly improved with increasing aging time. The main reason for the reduction of soil strength is the calcium carbonate crystals and magnesite microcracks produced by lime and MgO in the later stage of slaking. Full article

Due to the effects of time and space, there is a continuous deterioration of the surface layers of earthen sites and a corresponding decline in soil stability. Evaluating the stability of these sites is very important for potential site restoration. In this study, we analyze, evaluate, and summarize the factors that adversely affect the ancient moat site in Liye, a town of Longshan County, Hunan Province, China, through on-site investigation, sampling, and testing. An X-ray diffractometer and a scanning electron microscope were used to analyze the chemical composition and microstructure of the soil sample of the trench, and the ABAQUS software was used to produce two-dimensional models of seriously damaged areas. Using the strength reduction method, we obtained the minimum safety factor of the trench under its natural state and after rainfall; thus, the stability of the trench was examined under different working conditions. Additionally, we evaluated the safety and stability performance of the more dangerous sections to provide a basis for the safety evaluation, protection, and repair of the trench. The results show that rain erosion, freeze–thaw cycles, and man-made damage are the primary factors contributing to a deterioration of the soil site. The safety factor of the trench is found to decrease with increases in water content; thus, water has an impact on the strength of the site wall. The wall soil has larger pores and more initial cracks than does the trench soil, which is easy to peel off. As a result, there is a high probability of a secondary deformation of the wall slope. Our results identify the real state of the existing site and provide both a basis for stability evaluation and a scientific formulation for restoration schemes. Full article

This paper proposes a combined methodology for the quantitative analysis of the correlations between the monitored influencing environmental factors and the water saturation induced deterioration of earthen relics in a humid area. The Archaeological Ruins of Liangzhu City that have been exposed and severely damaged in a humid environment with high water content and dry–wet cycles are chosen as examples. A monitoring system including atmospheric, groundwater, soil moisture conditions, and images of the surface was installed. Based on the proposed methodology, 11 key influencing indexes involving groundwater, soil moisture and temperature at different depths, atmospheric radiation, and rainfall for the water saturation induced deterioration are investigated, and their correlation is described by a regression model. The weight rankings of influencing factors to the deterioration of the research area are calculated. The results can help quantitatively control the atmospheric environment where the earthen relics are located and can promote the conservation of the archaeological ruins in the humid environment. Full article

An understanding of the changes of the rammed earth temperature of earthen ruins is important for protection of such ruins. To predict the rammed earth temperature pattern using the air temperature pattern of the monitoring data of earthen ruins, a pattern prediction method based on interesting pattern mining and correlation, called PPER, is proposed in this paper. PPER first finds the interesting patterns in the air temperature sequence and the rammed earth temperature sequence. To reduce the processing time, two pruning rules and a new data structure based on an R-tree are also proposed. Correlation rules between the air temperature patterns and the rammed earth temperature patterns are then mined. The correlation rules are merged into predictive rules for the rammed earth temperature pattern. Experiments were conducted to show the accuracy of the presented method and the power of the pruning rules. Moreover, the Ming Dynasty Great Wall dataset was used to examine the algorithm, and six predictive rules from the air temperature to rammed earth temperature based on the interesting patterns were obtained, with the average hit rate reaching 89.8%. The PPER and predictive rules will be useful for rammed earth temperature prediction in protection of earthen ruins. Full article