面向材料老化的遗址土特性研究——以锁阳城遗址为例

The properties of earthen monument soil oriented the material aging: A case study of the Suoyang ancient city

暴露在自然环境中的土遗址在降雨、风沙和温度变化的长期影响下,材料功能不断退化。以锁阳城遗址土为研究对象,测试遗址土物理、化学、热学和力学特性,为开展土遗址建筑材料老化机理研究提供基本参数。结果表明,不同方位城墙遗址土均为低液限黏土,矿物成分主要为石英、长石、云母、绿泥石、方解石和白云石,易溶盐主要为NaCl和CaSO_(4)。不同方位城墙土体颗粒及矿物组成造成物理力学性质差异。东城墙的可溶盐总量较大,矿物风化程度最大。西城墙土体的导热系数和热扩散系数最小,热劣化损伤程度最小。原生夯土比重塑试样的结构性更好,具有较高的抗压强度和抗剪强度。在土遗址夯筑砌补加固施工过程中,分层夯筑有利于提高结构稳定性。

Due to exposing to atmospheric environment, the material of earthen monument sites deteriorated under the long-term influence of rainfall, wind-sand and temperature changes. In order to provide the basic parameters for the further research on the mechanism of materials aging, the world heritage site of Suoyang ancient city was taken as a research object, the physical, chemical, thermal and mechanical properties of the earthen monument soil were tested and analyzed through laboratory tests. The results show that the soil used for walls construction in different directions are low liquid limit clay, the mineral composition is mainly quartz, feldspar, mica, chlorite, calcite and dolomite, and the soluble salts are mainly NaCl and CaSO_(4). The composition of soil particles and minerals in different direction cause the differences of physical and mechanical properties. The total amount of soluble salt in the east wall is larger, and the degree of mineral weathering is the highest.The thermal conductivity and diffusivity of soil in the west wall is the lowest, and the thermal degradation damage degree is the largest. The structure of primary rammed earth is better than the remolded sample, and it has higher mechanical properties of resisting compression and shear damage. In the process of soil ruins reinforcing, the layered ramming is beneficial to improve the structural stability.