大河村遗址仰韶文化房基保护加固修复

On the Protection and Restoration of House Foundation(F1-F9) of Yangshao Culture in the Dahe Village site

大河村遗址仰韶房屋基址采用“木骨整塑”的建筑方法,墙壁及地坪用火烧烤成砖红色,是我国迄今为止发现的保存较好的史前居住基址。考古发掘后受红烧土材料及建造工艺、自然因素和保存环境的影响,房基红烧土墙体出现坍塌、开裂、剥离、脱落、酥碱粉化等病害,影响基址的稳定性、完整性及长期保存与展示。在对房基病害详细勘察基础上,对房基现存主要病害进行治理,提高了房基墙体红烧土的强度,防止房基墙体病害的继续发展,减缓风化破坏速度,保证房基在目前保存环境条件下的安全性、完整性和稳定性。

As a typical representative of Yangshao culture in Central China, the archaeological site of Dahe Village possesses the house foundation ruins which is the best preserved prehistoric residence foundation to date in China. The remnant of foundation keeps a comparatively complete architecture pattern, especially the revealing of a relatively holistic layout of “suite style” residence with interconnected rooms. The foundation has been built with the method of “wooden(lattice of wattle) framework and entire molding(baking the house of brick-like walls as a whole)”, and the techniques of fire burning and non-burning could both be found in its walls and rammed floor. This foundation provides important physical evidence for the study on the construction methods of prehistoric architecture foundation, and therefore possesses bountiful value in terms of history, art and science. In this paper, the major object under protection--house foundation(F1-F9), which has been housed inside the museum upon its original place after archaeological excavation, suffers an array of damages in the wall like collapsing, cracking, peeling off, falling off, and alkali efflorescence(into dusts)as the combined result of its building material(brick-red burnt earth), the construction technique, natural factors and the conservation condition. These damage issues would severely affect the stableness and completeness of the house foundation, as well as its longrange preservation and exhibition. To mend and eliminate the damages in the foundation, curb the weathering process of the ruins, and preserve and display the whole foundation in a more scientific way, we focus on the material and the techniques for the protection and restoration of brick-red burned earth of the house foundation, attempting to resolve the key technical problems of protection of such earth.Employing a multitude of methods including literature study, on-the-spot survey, comprehensive analysis, and on-site testing,we conduct an over-all archaeological reconnaissance on the current status of the house foundation, summarize the types of damage affecting scientific conservation and their features, and explore the protection material and technique directed against specific types of damage based on the reconnaissance result. On top of the research on the key technique of relic protection and restoration against various types of damage through experiments both in laboratory and on sites, we also apply these techniques to the realistic practice of protection and restoration project in order to test the research result. In this way, we systematically conclude a relatively complete set of protection and restoration techniques for the house foundation ruins of brick-red burned earth, after conducting on-site survey,experiments both in the lab and in the field on the protection material, and practical research of the protection project. In terms of protection materials, we restore the relics with the repairing and grouting material composed of hydraulic lime and additives including brick-red burned earth, water-reducing agent and easily dispersible fiber, and then carry out evaluation on the suitability of materials in terms of color, density, hydroscopicity, porosity, and strength. While in the research of protection technique, we mainly focus on the following methods: reinforcement by joining the falling or splintering brick-red burned earth clods, grouting the swollen and peeling part of the wall, and crack filling in the wall. Testing of pertinent research is performed in virtue of the simultaneous courses of design and construction of the protection project.Based on the on-site survey, the research on the protection and restoration materials and techniques, and the corresponding engineering practice, we come up with the suitable materials and key techniques for the protection of brick-red burned earth sites, which not only helps keep the ruins of house foundation of Yangshao culture in Dahe Village in a relatively safe condition, technically bolster the scientific conservation of house foundation, but also offers a research basis for subsequent exploration on the value of the house foundation and its exhibition.