The Study On The Control And Influence Elements Of Wave-induced Silty Soil Sliding In The Yellow River Subaqueous Delta

There exist various engineering geological hazards such as collapse pits, slope failure, silt flows in the Yellow River Subaqueous Delta. With the exploitation of ocean oil and gas resources, the port and harbor construction and the sea-floor engineering facilities are getting more and more, while ocean engineering facilities are damaged caused by marine geological hazards, of which the wave induce the silty soil weakening and sliding is an important form.The silty soil of the Yellow River Subaqueous Delta is study object, and the dynamic triaxial test was employed to study the rule of dynamic shear strength of the silty soil with the oscillation time. Express the soil strength in the effective strength index, and analyzed the control elements and influence factors of wave-induced silty soil sliding in the Yellow River Subaqueous Delta using the wave-induced soil sliding calculation procedures.In the study, the dynamic triaxial test were employed to simulate the wave action, the dynamic strength of the silty soil of different clay content (3%, 9%, 15%) were studied, and the test results show that the dynamic strength of the silty soil of different clay content are all reduced in the wave action, and the dynamic strength is the weakest when the clay content is 9%. The slip surface was assumed circular arc, using Bishop Method, the equation of the wave-induced soil sliding safety coefficiency K expressed by the effective strength index. According to field conditions in the Yellow River Delta, using Stokes theory, the range of the soil effective strength index was obtained when the soil could slide, and the range of c′andφ′are 0-19.5kPa and 0-25.5°, when the wave height is 5.2m, the wave periodic time is 8.6s. The safety coefficiency K is controlled by the soil effective strength index and the soil effective volume weightγ′, and influenced by the water depth h and the wave elements(H and T): the safety coefficiency K and c′,φ′,γ′, h, T are positive correlations, while it and H is negative correlation.Last, wave-induced silty soil sliding theory was applied to analyze the formation of the partial disturbed stratum existing in the shallow stratum and the monolithic sand in the Yellow River Subaqueous Delta.