Qingdao Underground Space Resource Revaluation Method And Its Application

Underground space is a kind of valuable space resource of a city.Development and utilization of underground space can effectively expand the urban space capacity,improve the urban environment and alleviate the urban traffic contradiction.With the rapid development of Qingdao’s economy,the shortage of urban land is becoming increasingly prominent.How to fully and reasonably develop the underground space resources in Qingdao has become an increasingly concerned issue.Therefore,the research on the key technologies of underground space development evaluation has also been put on the agenda.According to the way of ground penetrating radar,mixed source surface wave,sub-bottom profile and borehole calibration,the different degrees of weathering surface,fracture zone and fault can be identified,and the main rock-soil structure of Qingdao underground space is also identified to be granite.The urban with granite geological condition has the features of stable geological structure,waterproof and anti-collapse,which is suitable for the development and utilization of underground space resources with good engineering conditions.On the basis of summarizing the quality evaluation methods of underground space,through field exploration and drill hole sampling,the geomorphic types,engineering geology,hydrogeological conditions,adverse geological processes and human factors in Qingdao are analysed and the geological evaluation model of underground space in Qingdao is established by this paper.The engineering geological problems that influence the development and utilization of Qingdao underground space are mainly the thickness of soft soil and the type of rock and soil mass;the hydrogeological problems are mainly the groundwater level,water inflow,groundwater corrosiveness and aquifer thickness;and the adverse geological structure mainly includes the active fault zone;geological hazards include collapse,landslide and debris flow.The quality evaluation index of Qingdao underground space is more uniform and the most suitable evaluation methods for Qingdao underground space——analytic hierarchy process(AHP)combined with fuzzy mathematics method are adopted.To verify the rationality of the evaluation model,this paper selects Hongdao,a typical area of Qingdao,as the study area,and put the model into to practice.The suitability evaluation of the underground geological environment in Hongdao is carried out by using AHP-fuzzy comprehensive evaluation method,and the satisfactory results are obtained.The evaluation results show that the first-class area for underground space development in Hongdao District accounts for 45.3% of the total area of Hongdao,the second-class accounts for 6.2%,the third-class accounts for48.2%,and the fourth-class accounts for 0.3%.The research results of this paper are suitable for the evaluation of underground space resource in Qingdao,which can promote the research on the key technologies of underground space development and evaluation in Qingdao to a certain extent.