2002 Vol. 24, No. 6
Display Method:
2002, 24(6): 1-10.
Abstract:
A ccording to the character istics of vertical thermal structure of intermediate cold water,and considering the sea surface thermal and dynamical forcing factors,the shear stress and entrainment heat exchange in the interfaces of water layers,heat advection,mixing and topographic effect,firstly the closedly relevant equations are derived by vertical integrating whole ocean and each layer,respectively based on primitive momentum,continuity and heat conduction equations.The equations can describe wind-driven interface fluctuation,the mean velocity and temperature fields in each layer.And after solving mean temperature field in each water layer Tk(k=1,2,3,4), the characterizing temperature in each relevant water interface are obtained,on the basis of the relation between Tk and characterizing temperature.Finally,the three-dimensional heat structure of ocean with intermediate cold water is constructed by means of temperature profile expression.In order to verify the function of the model,the trial predictions of three-dimensional thermal structure in the study sea area on 15 May are made by valid time of 5 days. The comparison between the trial results and the measured ones is also carried out.The results show that the mean absolute error of water temperature trial prediction equals 0.25℃,so the results of the trial prediction is satisfactory.
A ccording to the character istics of vertical thermal structure of intermediate cold water,and considering the sea surface thermal and dynamical forcing factors,the shear stress and entrainment heat exchange in the interfaces of water layers,heat advection,mixing and topographic effect,firstly the closedly relevant equations are derived by vertical integrating whole ocean and each layer,respectively based on primitive momentum,continuity and heat conduction equations.The equations can describe wind-driven interface fluctuation,the mean velocity and temperature fields in each layer.And after solving mean temperature field in each water layer Tk(k=1,2,3,4), the characterizing temperature in each relevant water interface are obtained,on the basis of the relation between Tk and characterizing temperature.Finally,the three-dimensional heat structure of ocean with intermediate cold water is constructed by means of temperature profile expression.In order to verify the function of the model,the trial predictions of three-dimensional thermal structure in the study sea area on 15 May are made by valid time of 5 days. The comparison between the trial results and the measured ones is also carried out.The results show that the mean absolute error of water temperature trial prediction equals 0.25℃,so the results of the trial prediction is satisfactory.
2002, 24(6): 11-19.
Abstract:
Using meteorological data of field observation in 1989~2000,especially polar orbit high-resolution NOAA satellite cloud maps received from the Antarctic expedition vessel since 1997,the for mation and development of the Prydz Bay cyclone are studied.Some new view points are suggested such as:when surround-polar cyclone enters the Prydz Bay,it can also intensify and develop in summer;cyclone can also develop in the easterlies in this bay.These view points revise old incomplete view-point that the Prydz Bay is a burial ground of cyclone,and also further consummate formation-development theory of surround-cyclone in the Antarctic westerlies and cy clone in the A ntarctic easterlies.The mechanism of ice-ai-rsea interaction in the Prydz Bay is studied,and the physical process of cyclone formation-development is explained.By use of wholly dynamic transportation method,an energy exchange case of a cyclone,which explosively developed after entering the Prydz Bay,is calculatee.It is pointed that when cyclone passes through ice dam and enters the Polynya,it can obtain a great number of heat energy and develop rapidly into a very strong cyclone with Antarctic feature.In this case wind force was as strong as 12 grade,with 10 min average wind speed of 38 m/s,and instant aneous wind speed of 100 m/s.
Using meteorological data of field observation in 1989~2000,especially polar orbit high-resolution NOAA satellite cloud maps received from the Antarctic expedition vessel since 1997,the for mation and development of the Prydz Bay cyclone are studied.Some new view points are suggested such as:when surround-polar cyclone enters the Prydz Bay,it can also intensify and develop in summer;cyclone can also develop in the easterlies in this bay.These view points revise old incomplete view-point that the Prydz Bay is a burial ground of cyclone,and also further consummate formation-development theory of surround-cyclone in the Antarctic westerlies and cy clone in the A ntarctic easterlies.The mechanism of ice-ai-rsea interaction in the Prydz Bay is studied,and the physical process of cyclone formation-development is explained.By use of wholly dynamic transportation method,an energy exchange case of a cyclone,which explosively developed after entering the Prydz Bay,is calculatee.It is pointed that when cyclone passes through ice dam and enters the Polynya,it can obtain a great number of heat energy and develop rapidly into a very strong cyclone with Antarctic feature.In this case wind force was as strong as 12 grade,with 10 min average wind speed of 38 m/s,and instant aneous wind speed of 100 m/s.
2002, 24(6): 20-33.
Abstract:
Striping is a common phenomenon in remote sensing data,but relatively little work has been done in the realm of CCD.A ccording to the characteristics of HY-1 CCD push-broom multispectral camera and the result of pre-launch radiometric calibration,striping arising from the nonuniformity of the detectors is removed using a quantitative method by estimating equalization curves.This method can preserve the physical meaning of the raw data,and can work together with "in-orbit" calibration without much modification.
Striping is a common phenomenon in remote sensing data,but relatively little work has been done in the realm of CCD.A ccording to the characteristics of HY-1 CCD push-broom multispectral camera and the result of pre-launch radiometric calibration,striping arising from the nonuniformity of the detectors is removed using a quantitative method by estimating equalization curves.This method can preserve the physical meaning of the raw data,and can work together with "in-orbit" calibration without much modification.
2002, 24(6): 34-48.
Abstract:
Concentrations and different distribution patterns of n-alkanes in sediments from the Chukchi Sea and, Bering Sea in the Arctic are reported.Factor statistical analysis method is used to study the contaminated source of n-alkanes and paleoenv ironment.The result shows that n-alkanes is in the range of nC15～nC33,n-alkane distribution patterns are characterized by two modes.The first mode with high molecular range for nC25～nC27 being MH and CPI>1 indicates the abundances of terrigenous plantorigin.The second mode with low carbon range for nC17～nC20 being MH and CPI>1 shows that it had more marine biological inputs.The contribution of terrigenous origin is the larger one,with Pr/Ph>1 of the depositional environment,which has strong reducing action.The result of factor analysis is in correspondence with composition indexes of n-alkanes in the sediment.
Concentrations and different distribution patterns of n-alkanes in sediments from the Chukchi Sea and, Bering Sea in the Arctic are reported.Factor statistical analysis method is used to study the contaminated source of n-alkanes and paleoenv ironment.The result shows that n-alkanes is in the range of nC15～nC33,n-alkane distribution patterns are characterized by two modes.The first mode with high molecular range for nC25～nC27 being MH and CPI>1 indicates the abundances of terrigenous plantorigin.The second mode with low carbon range for nC17～nC20 being MH and CPI>1 shows that it had more marine biological inputs.The contribution of terrigenous origin is the larger one,with Pr/Ph>1 of the depositional environment,which has strong reducing action.The result of factor analysis is in correspondence with composition indexes of n-alkanes in the sediment.
2002, 24(6): 49-58.
Abstract:
The errors of the cross-sectional sediment flux estimation mainlyorig in from survey sitelay out and flux calculation method.The flux model should copy with the principle of the minimum statistical errors of flux estimation.A grid with equal cell area is designed since only this type of grid introduces the fewest statistical errors in the flux estimation.Considering the sediment of different grain-sizes has different properties and transport behaviors,fractional concentration of suspended sediment is taken to estimate the various fractional fluxes.Vertical interpolation of the variables takes alogarithmic method and horizontal interpolation takes a cubic spline method. The cros-ssectional fractional flux model of suspended sediment in a tidal estuary is further developed and applied to the estimation of fractional sediment fluxes and sediment transport mechanism in the Changjiang Estuary. The cross-sectional sediment fluxes in the spring tide are characterized by larger in wards and larger outwards transportations with the latter being larger than the former,while sediment fluxes in the neap are characterized by smaller inwards and smaller outwards transports with the latter being larger than the former. The principal transport mechanisms of residual fluxes are Lagrangian transport and tidal pumping.
The errors of the cross-sectional sediment flux estimation mainlyorig in from survey sitelay out and flux calculation method.The flux model should copy with the principle of the minimum statistical errors of flux estimation.A grid with equal cell area is designed since only this type of grid introduces the fewest statistical errors in the flux estimation.Considering the sediment of different grain-sizes has different properties and transport behaviors,fractional concentration of suspended sediment is taken to estimate the various fractional fluxes.Vertical interpolation of the variables takes alogarithmic method and horizontal interpolation takes a cubic spline method. The cros-ssectional fractional flux model of suspended sediment in a tidal estuary is further developed and applied to the estimation of fractional sediment fluxes and sediment transport mechanism in the Changjiang Estuary. The cross-sectional sediment fluxes in the spring tide are characterized by larger in wards and larger outwards transportations with the latter being larger than the former,while sediment fluxes in the neap are characterized by smaller inwards and smaller outwards transports with the latter being larger than the former. The principal transport mechanisms of residual fluxes are Lagrangian transport and tidal pumping.
2002, 24(6): 59-66.
Abstract:
Four methods are used to estimate the heat flux from the hydrothermal system to the ocean.The heat flux from high temperature vents and low temperature warm water diffusion fields is about 357 GW.The heat flux from bottom thermal boundary layer is 32 GW.Based on Baker's linear relationship between spreading rate and plume incidence,the possibly total hydrothermal fields on the whole world ocean are calculated and then their heat flux estimate is about 1 086 GW.Based on the spreading axiscrust cooling model the result is about 592 GW.From the results it can be seen that the heat flux from the hydrot hermal system to the world ocean may be tens to thousands giga-watt on one hand,and on the other hand it is well known that it is not easy to estimate it actually now.The great differ ence comes mainly from limited knowledge about the distribution of the hydrothermal fields on the world ocean.The abovementioned analysis is shown that though the heat flux from the hydrothermal system to the ocean is much smaller than the heat flux from the solar radiation to the ocean,but concerning the different ways of supplying the world ocean with heat,much attention should be paid to the effects of the hydrothermal activity on the world ocean current and world climate.
Four methods are used to estimate the heat flux from the hydrothermal system to the ocean.The heat flux from high temperature vents and low temperature warm water diffusion fields is about 357 GW.The heat flux from bottom thermal boundary layer is 32 GW.Based on Baker's linear relationship between spreading rate and plume incidence,the possibly total hydrothermal fields on the whole world ocean are calculated and then their heat flux estimate is about 1 086 GW.Based on the spreading axiscrust cooling model the result is about 592 GW.From the results it can be seen that the heat flux from the hydrot hermal system to the world ocean may be tens to thousands giga-watt on one hand,and on the other hand it is well known that it is not easy to estimate it actually now.The great differ ence comes mainly from limited knowledge about the distribution of the hydrothermal fields on the world ocean.The abovementioned analysis is shown that though the heat flux from the hydrothermal system to the ocean is much smaller than the heat flux from the solar radiation to the ocean,but concerning the different ways of supplying the world ocean with heat,much attention should be paid to the effects of the hydrothermal activity on the world ocean current and world climate.
2002, 24(6): 67-75.
Abstract:
The epidemiological investigations on the disease and death in mature eggs,embryonic developmental periods and larvae populations[including oocytes,fertilized ovum,early embry onic phase larvae(6h),D-shaped phase larvae(24h),early umbophase larvae,umbophase larvae,post umbophase larvae and eyespot phase larvae] in Luhuitou pearloyster of Mariculture Farm of Sany a City,Hainan Province in April 1995 show that there are two peaks of mortality rates which occurred in early umbo phase or umbophase and post umbophase(Figs 1~3 and Table 1)respectively from preembryonic developmental periods to larvae phases.It indicates that the onset and death of Pinctada maxima larvae populations followed a pattern of outbreak.Between the prevalence,intensity of RLO infection and the mortality rates of larvae populations have obviously positive corr elatio ns.Generally,every peak of RLO infection is always followed by a peak of mortality rate of larvae hosts,and the mortality rates of larvae hosts declined with decrease of RLO infection(Figs 1~3).Under the transmission electron microscopy(TEM)no rickettsia-like organisms were disco vered in oocytes,fertilized ovum and early embryonic phase larvae(6h).The RLO inclusions occurred first in the D-shaped phase larvae(24h)under histological examination.Absences of RLO in transmission electron examination of oocytes of RLO-infected adult females,fertilized ovum and early embryonic phase larvae(6h)indicate that RLO may not be transmitted transovarially.But RLO for hostinfection may be transmitted by contact transmission since RLO inclusions were firstidentified regularly in the D-shaped phase larvae (24h),while these D-shaped phase larvae were still unable to take food furing hatching 24.In addition,the result of epidemiolo gical investigation shows that no observable death occurred in the D-shaped larvae populations,but early obvious death occurred in larvae populations in the seventh day after fertilization,and the mortality rate is about 21.80%.It indicates that there was a incubation period from RLO infection for host(D-shaped phase larvae) to host onset and death occurred clinically.
The epidemiological investigations on the disease and death in mature eggs,embryonic developmental periods and larvae populations[including oocytes,fertilized ovum,early embry onic phase larvae(6h),D-shaped phase larvae(24h),early umbophase larvae,umbophase larvae,post umbophase larvae and eyespot phase larvae] in Luhuitou pearloyster of Mariculture Farm of Sany a City,Hainan Province in April 1995 show that there are two peaks of mortality rates which occurred in early umbo phase or umbophase and post umbophase(Figs 1~3 and Table 1)respectively from preembryonic developmental periods to larvae phases.It indicates that the onset and death of Pinctada maxima larvae populations followed a pattern of outbreak.Between the prevalence,intensity of RLO infection and the mortality rates of larvae populations have obviously positive corr elatio ns.Generally,every peak of RLO infection is always followed by a peak of mortality rate of larvae hosts,and the mortality rates of larvae hosts declined with decrease of RLO infection(Figs 1~3).Under the transmission electron microscopy(TEM)no rickettsia-like organisms were disco vered in oocytes,fertilized ovum and early embryonic phase larvae(6h).The RLO inclusions occurred first in the D-shaped phase larvae(24h)under histological examination.Absences of RLO in transmission electron examination of oocytes of RLO-infected adult females,fertilized ovum and early embryonic phase larvae(6h)indicate that RLO may not be transmitted transovarially.But RLO for hostinfection may be transmitted by contact transmission since RLO inclusions were firstidentified regularly in the D-shaped phase larvae (24h),while these D-shaped phase larvae were still unable to take food furing hatching 24.In addition,the result of epidemiolo gical investigation shows that no observable death occurred in the D-shaped larvae populations,but early obvious death occurred in larvae populations in the seventh day after fertilization,and the mortality rate is about 21.80%.It indicates that there was a incubation period from RLO infection for host(D-shaped phase larvae) to host onset and death occurred clinically.
2002, 24(6): 76-83.
Abstract:
A grid of 22 stations,giving a broad geographic coverage of the Bohai Sea and the Bohai Straits was selected.Undisturbed sediments were collected from sampling stations during cruises in July 1997,in September/October 1998 and again in April/May 1999.Based on the the results of Juario,the aver ag e biomass 0.404 g/(m2·a)o f meiofauna(including nematode,Harpacticoida,bivalve larvae,Polychaeta and Kinor hyncha)in the Bohai Sea is given and accounts for 4.5% of the macrofauna in the Bohai Sea.The horizontal distribution of the biomass of meiofauna shows that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruise and it decreased at the stations near the straits mouth and increased at Station B1 in 1999 cruise.The annual average production in the Bohai Sea is 3.636 g/(m2·a),calculating in term of the formula P=9B. Compared with the biomass of other sea areas in the world,the biomass of the Bohai Sea is hear but slightly low. The individual average dry weight of nematodes given by different authors is analysed.
A grid of 22 stations,giving a broad geographic coverage of the Bohai Sea and the Bohai Straits was selected.Undisturbed sediments were collected from sampling stations during cruises in July 1997,in September/October 1998 and again in April/May 1999.Based on the the results of Juario,the aver ag e biomass 0.404 g/(m2·a)o f meiofauna(including nematode,Harpacticoida,bivalve larvae,Polychaeta and Kinor hyncha)in the Bohai Sea is given and accounts for 4.5% of the macrofauna in the Bohai Sea.The horizontal distribution of the biomass of meiofauna shows that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruise and it decreased at the stations near the straits mouth and increased at Station B1 in 1999 cruise.The annual average production in the Bohai Sea is 3.636 g/(m2·a),calculating in term of the formula P=9B. Compared with the biomass of other sea areas in the world,the biomass of the Bohai Sea is hear but slightly low. The individual average dry weight of nematodes given by different authors is analysed.
2002, 24(6): 84-91.
Abstract:
The organic carbon budget of shrimp polyculture ecosystems is studied with five experimental enclosures. The results show that:(1)The total income of organic carbon fluctuated between 4 847.46 and 6 154.67 g, averaging 5 646.94g.The average ratio of this income to its components(total organic carbon income:phytoplankton production:periphyte production:feed casted)is 1:0.73:0.11:0.16.(2)The total outcome of organic carbon fluctuated between 3 310.28 and 3 974.79 g,averaging(3 644.21±281.44)g.The average ratio of this outcome to its components(total organic carbon outcome to plankton community respiration to per iphyton respiration to benthal respiration to cultured animal production to cultured animal respiration)is 1:0.53:0.19:0.15:0.04:0.09.(3)The organic carbon accumulation fluctuated between 1 383.61 and 2 707.47 g,averaging(2 002.73±546.76)g perenclosure,which is 26%~44% of the total income of organic carbon.The sequence of the enclosures in organic carbon accumulation is Y5(Penaeus chinensis-Argoprcten irradians)greater than Y7 (Penaeus chinensis-O.niloticus)greater than Y4(O.mossambicus)g reater than Y4(Penaeus chinensis)greater t han Y5(Chinensis chinensis-O.niloticus-O.mossambicus-Sinonovacula constricta)greater than Y6 (Penaeus chinensis-Sinonovacula constricta).(4)The average transformation rate of organic carbon income to Penaeus chinensis is(1.77±0.62)%(Y6>T5>Y4>Y5>Y7),and that to total cultured animals is(2.18±0.79)%(T5>Y6>Y5>Y4>Y7).
The organic carbon budget of shrimp polyculture ecosystems is studied with five experimental enclosures. The results show that:(1)The total income of organic carbon fluctuated between 4 847.46 and 6 154.67 g, averaging 5 646.94g.The average ratio of this income to its components(total organic carbon income:phytoplankton production:periphyte production:feed casted)is 1:0.73:0.11:0.16.(2)The total outcome of organic carbon fluctuated between 3 310.28 and 3 974.79 g,averaging(3 644.21±281.44)g.The average ratio of this outcome to its components(total organic carbon outcome to plankton community respiration to per iphyton respiration to benthal respiration to cultured animal production to cultured animal respiration)is 1:0.53:0.19:0.15:0.04:0.09.(3)The organic carbon accumulation fluctuated between 1 383.61 and 2 707.47 g,averaging(2 002.73±546.76)g perenclosure,which is 26%~44% of the total income of organic carbon.The sequence of the enclosures in organic carbon accumulation is Y5(Penaeus chinensis-Argoprcten irradians)greater than Y7 (Penaeus chinensis-O.niloticus)greater than Y4(O.mossambicus)g reater than Y4(Penaeus chinensis)greater t han Y5(Chinensis chinensis-O.niloticus-O.mossambicus-Sinonovacula constricta)greater than Y6 (Penaeus chinensis-Sinonovacula constricta).(4)The average transformation rate of organic carbon income to Penaeus chinensis is(1.77±0.62)%(Y6>T5>Y4>Y5>Y7),and that to total cultured animals is(2.18±0.79)%(T5>Y6>Y5>Y4>Y7).
2002, 24(6): 92-98.
Abstract:
Two sites are selected for the study of biofoulings,the Badouzi Harbour in the north of Taiwan,China and the Dapeng Harbour in the south.The result shows that the wet weight of biofoulings in these two harbours is low(1.42 and 1.08 kg/m2 respectively).Totally,60 species were recorded,only 7 of which were shared by these two harbours.Of 28 species recorded in the Badouzi Harbour,the dominant species are Uluaconglobata, Brachidontes variabilis,Dondostrea crenalifera,Balanus a. amphitrite and Styela canopus. Of 29 species recorded in the Dapeng Harbour,the dominant species are three species of seasquirts(P.constellotum,P. areolatum and S.canopus),Bugula neritina,three speciex of tube amphipod(C.insidiosum,E.brasiliensis and E.hoobeno),Mytilopsis sallei(alien species)and 12 species of diatoms,The biofoulings in these two half-closed harbours reflect the character istics of subtropical and tropical harbours.
Two sites are selected for the study of biofoulings,the Badouzi Harbour in the north of Taiwan,China and the Dapeng Harbour in the south.The result shows that the wet weight of biofoulings in these two harbours is low(1.42 and 1.08 kg/m2 respectively).Totally,60 species were recorded,only 7 of which were shared by these two harbours.Of 28 species recorded in the Badouzi Harbour,the dominant species are Uluaconglobata, Brachidontes variabilis,Dondostrea crenalifera,Balanus a. amphitrite and Styela canopus. Of 29 species recorded in the Dapeng Harbour,the dominant species are three species of seasquirts(P.constellotum,P. areolatum and S.canopus),Bugula neritina,three speciex of tube amphipod(C.insidiosum,E.brasiliensis and E.hoobeno),Mytilopsis sallei(alien species)and 12 species of diatoms,The biofoulings in these two half-closed harbours reflect the character istics of subtropical and tropical harbours.
2002, 24(6): 99-103.
Abstract:
The 18S rRN Agenes of "red-tide" related Phaeocystis sp.from the southeast coast of China,and its related species P.globosa and P.pouchetii are sequenced.Phylogenetic trees are constructed by using these 18S rDNA sequences.It is clearly shown that Phaeocystis sp.from the southeast coast of China is remarkably similar to several isolates of P.globosa rather than P.p ouchetii.The results demonstrate that the bloom-forming species of Phaeocystics most likely originated from an endemic warm-water species.The phenotypes of different members of the genus Phaeocystis are variable,apparently changing in response to environmental conditions.
The 18S rRN Agenes of "red-tide" related Phaeocystis sp.from the southeast coast of China,and its related species P.globosa and P.pouchetii are sequenced.Phylogenetic trees are constructed by using these 18S rDNA sequences.It is clearly shown that Phaeocystis sp.from the southeast coast of China is remarkably similar to several isolates of P.globosa rather than P.p ouchetii.The results demonstrate that the bloom-forming species of Phaeocystics most likely originated from an endemic warm-water species.The phenotypes of different members of the genus Phaeocystis are variable,apparently changing in response to environmental conditions.
2002, 24(6): 104-111.
Abstract:
The Huanghe River has run the current path since its last change of path in 1976.The river delta intrudes into the Laizhou Bay significantly.The effects of the Huanghe River Delta on the circulation and transportation of the eggs and larvae were investigated with a fine resolution 3-D shelf ocean model(HAMSOM).The effects are local but very significant.Before the intrusion of delta,the anti-cyclonic circulation dominates in the Laizhou Bay. At present,the circulation is totally different from that before the intrusion.Apair of headland eddies at the Huanghe River mouth is very significant.The change of the circulation is mainly due to the inter action between tides and bathymetry.Wind and baroclinic forcings also play an important role on the circulation,but the basic pattern remains.The eggs and larvae are transported tow ards the west part of bay before the intrusion of delta,which coincides with the historical nursery ground.At present,the eggs and larvae are trapped in the headland eddies, which has disadvantage on the later stage of larvae.The results may explain to some extent for the lost of the nursery ground of Peneous Chinensis.
The Huanghe River has run the current path since its last change of path in 1976.The river delta intrudes into the Laizhou Bay significantly.The effects of the Huanghe River Delta on the circulation and transportation of the eggs and larvae were investigated with a fine resolution 3-D shelf ocean model(HAMSOM).The effects are local but very significant.Before the intrusion of delta,the anti-cyclonic circulation dominates in the Laizhou Bay. At present,the circulation is totally different from that before the intrusion.Apair of headland eddies at the Huanghe River mouth is very significant.The change of the circulation is mainly due to the inter action between tides and bathymetry.Wind and baroclinic forcings also play an important role on the circulation,but the basic pattern remains.The eggs and larvae are transported tow ards the west part of bay before the intrusion of delta,which coincides with the historical nursery ground.At present,the eggs and larvae are trapped in the headland eddies, which has disadvantage on the later stage of larvae.The results may explain to some extent for the lost of the nursery ground of Peneous Chinensis.
2002, 24(6): 112-119.
Abstract:
Based on the u-p form of the gener alized formulation of two-dimensional Biots theory of dynamic consolidation,the finite element numerical procedure in time domain is developed to evaluate dynamic response of saturated seabed.The governing equations which are composed of static equilibrium conditions and Biots consolidation equation can be regarded as a special case.In comparative examples,the results from the degenerated method proposed agree well with the analytical solutions.In general,the effect of soil skeleton acceleration on effectivest resses and pore pressure can be neglected and the governing equations can be expressed by Biots theory. The upper coarse sand layer of layered seabed will not reduce the amplitudes of pore pressure remarkably at the shallow zone near the seabed surface,therefore the possible maximum liquefaction depth will not change.
Based on the u-p form of the gener alized formulation of two-dimensional Biots theory of dynamic consolidation,the finite element numerical procedure in time domain is developed to evaluate dynamic response of saturated seabed.The governing equations which are composed of static equilibrium conditions and Biots consolidation equation can be regarded as a special case.In comparative examples,the results from the degenerated method proposed agree well with the analytical solutions.In general,the effect of soil skeleton acceleration on effectivest resses and pore pressure can be neglected and the governing equations can be expressed by Biots theory. The upper coarse sand layer of layered seabed will not reduce the amplitudes of pore pressure remarkably at the shallow zone near the seabed surface,therefore the possible maximum liquefaction depth will not change.
2002, 24(6): 120-126.
Abstract:
2002, 24(6): 127-134.
Abstract:
2002, 24(6): 135-144.
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