3:45 PM - 4:00 PM
[HRE13-02] Characteristics of geological sedimentation around Yumeshima and bay area using borehole database
Keywords:Geo-Informatics, Osaka, Bayarea, subsurface geology
We investigated the characteristics of the geological ground using boring data around Yumeshima areas. Osaka Bay basically consists of alternating layers of marine clay and gravel. The gravel layer is sometimes deposited by cutting into the underlying clay layer.
In the development of the Bay Area, a sea wall is constructed, a sand layer (bedding layer) is created on the sea floor as a drainage layer, and then reclaimed soil is poured in to create land. Boring data exists from before the land reclamation to the present, and the past seafloor elevation was clarified from the boring information before the land reclamation, and the distribution and thickness of each marine clay layer was extracted from the information from the borings performed after the land reclamation, and changes therein were studied.
As land reclamation progresses, the elevation of the sea floor tends to gradually decrease due to overburden pressure, and at present data shows a subsidence of about 5 meters compared to before land reclamation. We also confirmed the depths of the top and bottom of each marine clay layer and examined their characteristics. The results suggest that there is an estuary of the former Osaka River (former Yodo River system) in the southern Yumeshima region.
In the development of the Bay Area, a sea wall is constructed, a sand layer (bedding layer) is created on the sea floor as a drainage layer, and then reclaimed soil is poured in to create land. Boring data exists from before the land reclamation to the present, and the past seafloor elevation was clarified from the boring information before the land reclamation, and the distribution and thickness of each marine clay layer was extracted from the information from the borings performed after the land reclamation, and changes therein were studied.
As land reclamation progresses, the elevation of the sea floor tends to gradually decrease due to overburden pressure, and at present data shows a subsidence of about 5 meters compared to before land reclamation. We also confirmed the depths of the top and bottom of each marine clay layer and examined their characteristics. The results suggest that there is an estuary of the former Osaka River (former Yodo River system) in the southern Yumeshima region.