Study On Geological Suitability Evaluation Of Urban Underground Space Development From 3D Perspective

At present,urban problems such as urban construction land shortage,ecological environment deterioration,and traffic congestion have seriously affected the stable development of cities.Expanding the space capacity of the city towards the underground space is considered an important measure to solve the urban problem.In order to prevent the waste of underground space resources caused by irrational development and the engineering and environmental geological problems caused by it,the rational and full development and utilization of underground space resources has attracted more and more attention.The geological suitability evaluation of underground space development has also attracted the attention of scholars as an important basic work for urban underground space development.On the basis of summarizing the influencing factors of urban underground space development geological environment,this paper analyzes the development of underground space at different depth levels from five aspects: topography,soil and rock conditions,hydrogeological conditions,tectonic geological conditions and adverse geological effects.The main geological influencing factors,and considering the two aspects of common factors and sensitive factors,respectively,the shallow,middle and deep suitability evaluation index system was constructed.The fixed value method for traditional weights ignores the influence of internal differences of evaluation indicators on the whole,and combines the idea of variable weight to construct a comprehensive evaluation model of variable weight.Then,by introducing the three-dimensional geological model as one of the evaluation elements into the evaluation,the three-dimensional evaluation result is obtained by using the two-dimensional coupling evaluation mode.Finally,this paper selects the core area of Jinan City as the research area,and conducts a case study on the hierarchical index system and the variable weight comprehensive evaluation model.The threedimensional visualization of the evaluation results is realized,and the two spatial perspectives of the plane and the vertical are compared and analyzed.The research results show that:(1)The underground space in the core area of Jinan downtown area accounts for more than 80% of the overall resources,and the underground space resources that can be developed are relatively abundant.(2)The variable weight comprehensive evaluation model is more discrete than the traditional fixed weight evaluation model,which can more accurately reflect the influence of the difference of geological condition index value on the development of underground space.At the same time,it can objectively evaluate the geological suitability of urban underground space development.(3)The 3D geological model is introduced into the evaluation model to evaluate the geological suitability of underground space development from a three-dimensional perspective,and more objectively reflect the distribution of the evaluation results in three-dimensional space,which can more effectively provide theory and science basis for the planning of urban underground space development.