The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. T...The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. The sediment consolidation settlements and its contribution to the topography change in the northern modern Huanghe River subaqueous delta are studied based on drilling data, laboratory experiment results, and water depth measurements of different time. The results show that the final consolidation settlement of drill holes in the study area is between 1.17 and 3.21 m, and mean settlement of unit depth is between 2.30 and 5.30 cm/m based on the one-dimensional consolidation theory and Plaxis numerical model. The final consolidation settlement obtained by Plaxis numerical model is smaller than that obtained by the one-dimensional consolidation theory, and the difference is 3.4%-39.9% between the methods. The contribution of the consolidation settlement to the topographical change is at 20.2%-86.6%, and the study area can be divided into five different regions based on different contribution rates. In the erosion area, the actual erosion depth caused by hydrodynamics is lower than the changes of measured water depth, however, the actual deposition amount caused by hydrodynamics is much larger than the changes of water depth obtained by measured data in the equilibrium and deposition areas.展开更多
Objective In geo-marine science,the generalized bottom boundary layer(BBL)represents a layer between sediments and seawater.The BBL plays an important role in geological,geobiochemical,geophysical and geotechnical r...Objective In geo-marine science,the generalized bottom boundary layer(BBL)represents a layer between sediments and seawater.The BBL plays an important role in geological,geobiochemical,geophysical and geotechnical research because it is the connection region of hydrosphere,展开更多
The in situ pore pressure response of silt under wave action is a complex process.However,this process has not been well studied because of limited field observation techniques.The dynamic response process is closely ...The in situ pore pressure response of silt under wave action is a complex process.However,this process has not been well studied because of limited field observation techniques.The dynamic response process is closely related to engineering geological hazards;thus,this process must be urgently explored.A long-term in situ observational study of the silt sediment pore water pressure response process under wave action was conducted in the subaqueous Yellow River Delta.The response characteristics of pore water pressure are affected by tidal level and wave height.Tidal level affects the overall trend of the pore water pressure response,while wave height influences the amplitude of the pore water pressure response.This study revealed a significant lag effect in the pore pressure response.The transient pore pressure in the seabed did not respond immediately to the wave-induced pressure stress on the seabed surface.This phenomenon may be attributed to the change in soil permeability.The maximum response depth was approximately 0.5 m with a 2 m wave height.A concept model of silt soil pore pressure response under different types of wave action was developed.The accumulation rate of the pore pressure is less than the dissipation rate;thus,the developed model highlights the oscillation pore pres-sure response mechanism.The highlighted response process is of considerable importance to transient liquefaction and the startup process of pore pressure response.展开更多
基金The National Natural Science Foundation of China under contract No.41206054the Basic Scientific Fund for National Public Research Institutes of China under contract No.2015G08the Open Fund of the Key Laboratory of Marine Geology and Environment,China Academy of Science under contract No.MGE2013KG06
文摘The sediments of the modern Huanghe River subaqueous delta are easily to generate settlement and lead to topography change which is due to fast deposition rate, high void ratio, moisture content and compressibility. The sediment consolidation settlements and its contribution to the topography change in the northern modern Huanghe River subaqueous delta are studied based on drilling data, laboratory experiment results, and water depth measurements of different time. The results show that the final consolidation settlement of drill holes in the study area is between 1.17 and 3.21 m, and mean settlement of unit depth is between 2.30 and 5.30 cm/m based on the one-dimensional consolidation theory and Plaxis numerical model. The final consolidation settlement obtained by Plaxis numerical model is smaller than that obtained by the one-dimensional consolidation theory, and the difference is 3.4%-39.9% between the methods. The contribution of the consolidation settlement to the topographical change is at 20.2%-86.6%, and the study area can be divided into five different regions based on different contribution rates. In the erosion area, the actual erosion depth caused by hydrodynamics is lower than the changes of measured water depth, however, the actual deposition amount caused by hydrodynamics is much larger than the changes of water depth obtained by measured data in the equilibrium and deposition areas.
基金supported by the National Natural Science Foundation of China (grants No.41427803 amd 41272316)
文摘Objective In geo-marine science,the generalized bottom boundary layer(BBL)represents a layer between sediments and seawater.The BBL plays an important role in geological,geobiochemical,geophysical and geotechnical research because it is the connection region of hydrosphere,
基金sponsored by the National Special Project for Marine Public Welfare Industry(No.201005005)the National Natural Science Foundation of China(Nos.42107207,41876066)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2020QD067)the Post-doctoral Innovation Project of Shandong Province(No.202002042)。
文摘The in situ pore pressure response of silt under wave action is a complex process.However,this process has not been well studied because of limited field observation techniques.The dynamic response process is closely related to engineering geological hazards;thus,this process must be urgently explored.A long-term in situ observational study of the silt sediment pore water pressure response process under wave action was conducted in the subaqueous Yellow River Delta.The response characteristics of pore water pressure are affected by tidal level and wave height.Tidal level affects the overall trend of the pore water pressure response,while wave height influences the amplitude of the pore water pressure response.This study revealed a significant lag effect in the pore pressure response.The transient pore pressure in the seabed did not respond immediately to the wave-induced pressure stress on the seabed surface.This phenomenon may be attributed to the change in soil permeability.The maximum response depth was approximately 0.5 m with a 2 m wave height.A concept model of silt soil pore pressure response under different types of wave action was developed.The accumulation rate of the pore pressure is less than the dissipation rate;thus,the developed model highlights the oscillation pore pres-sure response mechanism.The highlighted response process is of considerable importance to transient liquefaction and the startup process of pore pressure response.