The Study On The Seismic Stability Control Index System Of Rammed Earth Wall Ruins: ——An Example Of Suoyang City In Anxi County

As an important representative of the "Ancient Silk Road" culture,the rammed earth ruins of Suoyang City is of great scientific,historical and artistic value.Under the conditions of wind and sand erosion,unscientific protection and utilization,sunshine exposure,freeze-thaw cycles and man-made destruction,the ruins has developed cracks,missing soil and other serious diseases that affect its stability,while its structural stability has become a hidden danger because of its location in high intensity areas.Researchers have conducted ruins consolidation and conservation efforts focused on artifact salvage,lacking consideration of future earthquake impacts.Moreover,the existing research on the seismic stability of earth ruins also focuses on the qualitative relationship between ruins stability and influencing factors,and lacks the quantitative relationship between disease index and reinforcement technical index on the seismic stability of ruins.In view of the above key problems,this paper explores the relationship between disease,reinforcement methods and seismic stability of existing rammed earth ruins walls by combining field inspection,soil test,theoretical analysis and numerical calculation,and achieves the corresponding research results as follows.(1)Taking the perspective of diseases and reinforcement methods changing the structural form as the entry point,we comprehensively clarify the typical diseases and reinforcement methods for the Suoyang City ruins,deeply analyze the mechanisms of diseases and reinforcement methods affecting the structural stability,and lay a solid foundation for the establishment of a systematic and comprehensive stability control index system.(2)Through aerial mapping of the rammed earth ruins wall of the inner city of Suoyang City,the principles and key concerns to be followed by the UAV(unmanned aerial vehicle)tilt photogrammetry technology in modeling large earth ruins remains are summarized.The whole process and technical details of the UAV aerial photography modeling are refined,and the 3D(three-dimensional)model of the rammed earth wall is established and tested for modeling quality to provide a theoretical basis for similar work to be carried out in future.(3)With reference to the literature and the actual situation of the rammed earth wall ruins,we measure and count 3D model disease index parameters and analyze their correlation and typicality,then study the relationship between the index with higher correlation to reveal the inner connection of disease development and make theoretical interpretation.Finally,the atypical index are excluded and a primary stability control index system oriented to the disease and reinforcement methods is built.(4)This paper combines the research results to design multi-factor and multi-level orthogonal test,calculates the ultimate seismic loads corresponding to different parameter combinations according to the test scheme,and performs multiple nonlinear regression on the calculation results to establish the functional equations between the ultimate seismic capacity of the ruins and the influencing factors,The significance level of each index affecting the seismic capacity of the rammed earth wall is tested,and the contribution of each index to the stability of the ruins is derived,so as to establish the seismic stability control index system and provide reference for the stability evaluation and seismic strengthening of the rammed earth wall ruins.