Study On Active Faults And Stability Of Sanya New Airport And Its Adjacent Areas

In order to relieve the pressure of air transportation in Sanya City and better promote the construction of Hainan Free Trade Zone and the national "The Belt and Road Initiative" development strategy,the Government of Hainan Province plans to build a new airport in Sanya City by land reclamation in the offshore of Hongtang Bay.A good study on the basic geological conditions,the development of active faults and the stability of the proposed new airport and its adjacent areas will not only help to ensure the smooth development of the new airport project,but also provide some geological references for major engineering construction in Sanya area.In this paper,on the basis of summarizing and analyzing the previous research results,through remote sensing interpretation,field geological and geomorphic survey,sea drilling and optically stimulated luminescence(OSL)dating methods,combined with audio magnetotelluric,shallow formation profile,single channel seismic detection,multi-channel seismic detection and other geophysical detection means,The spatial distribution,activity and crustal stability of faults in the area of southern Hainan island and the project area of the proposed Sanya new airport are systematically studied,and the following understandings and results are obtained:(1)The optically stimulated luminescence age of fault gouge of NW direction Ledong-Tiandu fault in southern Hainan island is 36.8±4Ka.It is concluded that the fault had an active history since the Late Pleistocene,but its spatial location is far away from the proposed new airport,so it will not affect the project.(2)It is inferred that the possibility of the recent destructive large earthquake in southern Hainan island is small,on the basis of previous studies,the investigation of fault outcrop profile,and the analysis of historical earthquake development,combined with the characteristics of deep crustal structure and tectonic stress field.(3)A total of 4 faults in the proposed Sanya new airport and its adjacent areas were detected by geophysical means.By comparing the borehole data,it was inferred that the Hongtangwan fault and Xidaoxi fault in the sea area were early and middle Pleistocene faults.According to the fault activity classification of the four faults in the study area,it is considered that they are all inactive or weakly active faults since the late Pleistocene,which is far from the proposed new airport in Sanya and has little influence on the new airport project.(4)The reference work of regional crustal stability evaluation method,comprehensive fracture structure,geological characteristics,geological characteristics,geophysical and seismic activity and other aspects of the evaluation factors,and to evaluate the stability of the qualitative study area,think of the proposed new airport and adjacent regions sanya is located in stable tectonic area,but in stability of the field,The problems of land subsidence and sand liquefaction should be fully considered in the construction process.