古建筑基座渗漏监测及诱因分析

为研究某古建筑基座渗漏特征及其诱因，采用现场调研、水分场原位监测、室内试验和数值分析方法，针对基座水分场开展了系统研究，深入分析了基座渗漏病害根源、降雨期间基座内部水分场的时空分布特征和水分迁移规律。结果表明，古建筑基座渗漏的根源是降雨影响，与基座外侧的花坛浇灌用水无关，基座顶部以下2.0 m范围内易于受到降雨的影响，且水分有由基座顶部向基座底部迁移趋势，揭示出：基座顶部的海墁以下防渗层可能失效，基座内部夯土可能形成渗流通道；在2个水文年内，基座外墙以内的3.0 m范围内夯土基本达到饱和，易受到降雨影响而出现泛碱、掉皮、渗漏等现象，10个水文年后水分向基座劵门拱圈部位夯土迁移，并形成稳定水分场，在渗透压力下劵门拱圈部位形成流痕和墙皮脱落现象；通过多手段综合分析，能够深入了解基座病害的演化规律和形成机制，为类似古建筑基座的防渗漏修复措施的确定能够提供科学的参考。

Monitoring and inducement analysis of seepage of an ancient building base

To investigate the water seepage characteristics and formation mechanism in an ancient building base (ABB), site investigation, in situ monitoring, laboratory test and numerical methods are employed to study the water field in an ABB. The causes of water seepage, spatial-temporal distribution and migration of water during the rainfall are analyzed in detail. The research results show that the causes of water seepage of the ABB are rainfall infiltration rather than plants irrigation. The rainfall has a greater influence on 2.0 m depth rammed soil underneath the base top than the influence at the other positions, and the water has a tendency to migrate from the base top to base bottom. It is indicated that the impervious layer has been in disrepair for long years and the leakage pathway in the rammed soil has been generated. During 2 hydrological years, 3.0 m depth rammed soil adjacent to the side wall of ABB was saturated and was easily influenced by the rainfall infiltration, which caused bloom of the crystalline materials and occurrence of peeling and water seepage. After 10 hydrological years, the water migrated from the base top to the crown of city-gate, and water seepage and peeling happened. The evolution law and formation mechanism of water seepage hazards are analyzed in details through different approaches, and the results can provide scientific base for seepage prevention and restoration measures of the ABB.