基于多源监测数据的大雁塔近40年变形特征分析

Analysis on deformation characteristics of the Great Wild Goose Pagoda over the past 40 years based on multi-source monitoring data

针对西安市标志性古建筑大雁塔的倾斜问题,该文基于1985—2023年间的大雁塔倾斜小角法测量和水准测量数据,分析了塔身倾斜量和倾斜方向的变化、塔体各层的挠度变化特征,同时基于塔周边水准测量和InSAR测量结果分析了倾斜变化与地面沉降的关系。研究结果表明:大雁塔塔身倾斜主要是由于地下水位下降导致的不均匀地面沉降产生,自1985—2023年间,大雁塔的形变经历了“倾斜加剧”、“倾斜回归”、“逐步稳定”3个阶段,最大倾斜量达到1010.50 mm,倾斜方向为北偏西,大雁塔倾斜变形与其周边的地面沉降有着密切的联系,目前大雁塔处于相对稳定的状态。

As a landmark building and famous historical site in Xi'an, the Great Wild Goose Pagoda has been receiving much attention due to its inclined deformation and surrounding land subsidence. The inclined deformation of the Great Wild Goose Pagoda is mainly caused by uneven land subsidence due to the decrease in groundwater level. Focuses on the tilt deformation of the Great Wild Goose Pagoda, the changes in the tilt amount and direction of the tower body are analyzed as well as the deflection characteristics of each layer of the tower based on the tilt measurement data of small angle method and leveling to the Great Wild Goose Pagoda from 1985 to 2023.At the same time, the relationship between the tilt change of the Great Wild Goose Pagoda and ground subsidence is analyzed based on the results of leveling and InSAR measurements around the tower. The monitoring data shows that from 1985 to 2023,the deformation of the Great Wild Goose Pagoda has gone through three stages: “intensification of inclination”,“regression of inclination”,and “gradual stability”. The maximum inclination reaches 1 010.50 mm, and the inclination direction is northwest. The deformation of the Great Wild Goose Pagoda is closely related to the ground subsidence around it, and it is currently in a relatively stable state.