Weathering Durability Of Milan Ancient Earthen Architecture In Xinjiang

Milan Ancient Earthen Architectures(AEA) in Xinjiang along the Silk Road is located in the desert area due to the extreme natural conditions, which is suffered from strong wind erosion, rain erosion and human damages. This paper takes Milan AEA as the research object, based on the in-depth research of the historical evolution and the detailed survey of current situation of the remains, studied the conservation status,the environmental occurrence, and the main types, distribution and development of disease genesis mechanism. Representative soil samples were selected to do laboratory test mainly for physical properties, soluble salt composition analysis,mechanical properties etc to evaluate the engineering properties of the site soil.Compacted sample with dry density of 1.5 g/cm3 similar that of fort rammed earth, consolidated with Potasium Sitieate(PS) with concentration of 7%, 10%respectively Laboratory test results indicate that PS can effectively improve the soil strength, and the resistance to wind and rain erosion. Field tests were conducted on the yadan landform near the defensibly fort, consolidated with PS in concentration of3%, 5% and 7% respectively.The conclusions of this paper can be drawn as follows:1. Milan site is a well-conserved site of the Han and Tang dynasties culture on the ancient Silk Road. The remains one fort, thirteen pagodas, three Buddhist temples and two beacon towers, were builded by rammed earth or abode. These earthen architectures are endangered because of various diseases.2. The major diseases are sand-laden wind erosion and rain erosion in case of a sudden rain. The remaining forms are characterized by cellular wall face, surface flakes off, scouring on footing of wall, wall crack, collapse, and so on.3. The site soil has a varied density, and extremely low natural moisture content,which can be classified as low-liquid limit silt with poorly grain-size distribution and low plasticity. The site soil presents a weak alkaline property, and with no obvious salt injury.4. Laboratory test results show that PS reduce soil porosity, and increase strength significantly. Along with the increase of PS concentration, the consolidated soilexhibit a high property against wind erosion, and slake-durability enhance significantly with good permeability.5. In situ PS consolidation test results show that, with the increase of PS concentration, wind erosion damage area and depth decreases and the corrosion time prolonged. With respect to the surface spray penetration reinforcement, wall surface was flat after rain erosion; water carries the topsoil escaped. With respect to the PS drip seepage reinforcement, rain water flow into the holes, where the interior soil was eroded away and erosion pits were left.