Restrictive Evaluation Of Underground Space Development By Historical Relics In Xi'an

With the continuous progress of urbanization and the rapid development of the city,urban diseases such as parking difficulties,traffic congestion,and haze have become prominent,and the development and utilization of underground space has become the most important way to solve urban diseases and livable city construction.Xi'an is a historical and cultural city with many historical cultural relics,high quality,and wide distribution.Protecting historical relics scientifically is one of the unavoidable technological propositions in underground space development.Based on the analysis of the basic features of the historical relics of Xi'an City and their interaction with the underground space,a historical cultural relics classification scheme for the development of underground space was proposed,the additional stress distribution rules of different types of historical relics were revealed,and the development of underground space was explored.The influence of historical relics and the restrictive evaluation of historical relics on the development of underground space.The main results are as follows:(1)A historical cultural classification scheme for underground space development was proposed.Combining the distribution characteristics of historical relics,survey characteristics,basic types of foundations,characteristics of additional stress distribution,and comprehensive classification principles of above-ground and underground coordinated development principles,a historical cultural classification scheme for underground space development was proposed to divide Xi'an historical relics into square bases.Classes,square foundations,spherical foundations,natural archeology,underground chambers,and strip foundations.(2)Reveal the additional stress distribution law of different types of historical relics.Different types of historical relics were selected and the distribution of ground stress was simulated and calculated.The stress distribution of tower foundations in towers was generally saddle-shaped.The longitudinal depth of stress was 10m-20 m,and the horizontal influence was approximately 1.5 times that of the basic horizontal range.The ground stress distribution of the spherical foundation is controlled by the ball-shaped soil,and the foundation soil is diffused in the form of bubbles.However,the ground soil is hardly disturbed by additional stress,and the influence range is slightly larger than that of the spherical foundation soil;the buried natural natural historical relics The stress distribution is affected by the underground chambers,and the influence range is 3-5 times of the overall size of the chambers;the stress distribution of the urban wall strip foundation is gentle saddle shape,the depth of the additional stress is less than 20 m in depth,and the horizontal influence range is slight.Greater than the width of the wall.(3)Explored the impact of underground space development on historical relics.Using ABAQUS software,a underground space evaluation model for tower-type foundation and cultural relics of tower foundations,eight working conditions including different cross-sections,different excavation methods,and different excavation depths were designed to simulate different conditions.Under the conditions of working conditions,the safety impact of the cultural relics was determined;the spatial location of the development of the underground space resources adjacent to the historical relics was determined and the settling deformation range of historical relics would not exceed 30 m.(4)Completed the restrictive evaluation of historical relics on underground space development.Based on the systematic analysis of the distribution of additional underground stress of different types of historical relics and the influence of underground space development on historical relics,quantitative analysis of the restrictive effects of underground cultural space on the basis of the acceptable deformation range of cultural relics;from the perspective of the protection of historical relics The use of different types of historical relics for the use of underground space in the vertical and horizontal direction of safety,allowable development,and prohibition of development are proposed,and engineering measures and recommendations corresponding to different threshold ranges are proposed.