【摘要】 为研究坡顶裂隙分布对南京“包山式”城墙墙体稳定性的影响,采用ABAQUS软件建立南京城墙神策门段包山墙数值分析模型,运用扩展有限元法(XFEM)分析坡顶裂隙位置、深度对包山墙稳定性和受力性态的影响。结果表明:距离墙顶外边缘4m范围内的坡顶裂隙对城墙稳定性影响更为显著;裂隙深度对城墙土压力的影响存在临界深度,当裂隙深度超过2m后,裂隙深度增加对外包砌体的土压力影响很小;坡顶裂隙的位置及深度通过影响塑性滑裂面的延伸路径,进而对包山墙破坏模式产生影响;包山墙的安全系数与坡顶裂隙深度呈负相关,裂隙深度增加会加速塑性滑裂面的贯穿,影响包山墙的滑动破坏过程。在包山墙区域城顶进行景观设计时,应采取避开在距离墙顶外边缘4m范围内进行大型乔木绿化的策略以减缓包山墙稳定性的劣化。更多还原

【Abstract】 In order to study the influence of cracks at slope crest on the stability of the city wall embracing mountain in Nanjing,firstly,ABAQUS was used to establish the numerical model of the city wall in Shence-gate section,and then the extended finite element method(XFEM) was used to analyze the influence of crack location and depth on the stress behavior and stability of the wall.The results show that,cracks within 4m away from the wall outer edge has a significant impact on the stability of the city wall.There is a critical value of the crack depth.When the crack depth exceeds 2m,the increase of crack depth has little effect on the earth pressure of the city wall.The location and depth of cracks at slope crest would affect the extension path of the plastic sliding surface,and thus affect the failure modes of the city wall.The safety factor of the city wall embracing mountain is negatively correlated with cracks at slope crest,the increase of the crack depth will accelerate the penetration of the plastic sliding surface and affect the sliding failure process of the city wall.When landscape design is performed on the city wall crest area,large-scale tree planting within 4m from the wall outer edge should be avoided to protect the wall stability.更多还原