平遥古城墙稳定性分析研究

Study on Stability Analysis of Pingyao Ancient Wall

基于平遥古城墙的建筑形制,针对重力作用、重力和地震耦合、降雨导致的浸水软化三种工况,采用岩土摩尔-库仑本构模型的有限元分析技术,对城墙进行稳定性分析。得出以下结论:城墙在自重作用下其安全性满足要求;8度多遇地震作用下,夯土力学指标占比70%的墙体结构的安全稳定系数大于1.3,稳定性满足要求;在8度罕遇地震作用下,结构的安全稳定系数不满足要求,将会发生失稳破坏。城墙夯土的c、φ参数取值变化对结构的安全稳定性非常敏感;在长时间降雨历时、充分入渗作用下,结构的稳定安全系数较低,不满足稳定安全要求,如果此状态和地震耦合,稳定安全系数会进一步恶化。城墙防水、防渗是确保城墙稳定的关键。

Based on the architectural form of Pingyao Ancient Wall,aiming at the three working conditions of gravity,gravity and seismic coupling,and water softening caused by rainfall,the stability of the Pingyao Anciend Wall was analyzed with the finite element analysis technology based on the Mohr-Coulomb constitutive model.The following conclusions were drawn:under the action of self-weight,the safety and stability of the ancient wall could meet the requirements;under the action of 8-degree frequent earthquakes,the safety and stability coefficient of the ancient wall 70%is greater than 1.3,which could meet the requirements of stability;under the action of 8-degree rare earthquakes,the safety and stability coefficient of the ancient wall could not meet the requirements,and it would suffer instability damage.The change of parameters c andφof rammed soil is very sensitive to the safety and stability of the structure.Under the action of long duration rainfall and full infiltration,the stability and safety coefficient of the ancient wall is low which could not meet the requirements of stability and safety.If this state is coupled with earthquakes,the stability safety coefficient would declining further.Waterproofing and seepage prevention of ancient wall are the key to ensure the stability of it.