The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scou...The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipe- line located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which in- eluded a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage （MFL） sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage （MFL） detection results also reveal the possible connec- tion between long free spans and accelerated corrosion of the pipeline.展开更多
The Yellow River Delta (YRD) is one of the biggest deltas that have not been developed in the world. During the turn of the centuries, YRD development is listed in the two major projects in the new century by Shandong...The Yellow River Delta (YRD) is one of the biggest deltas that have not been developed in the world. During the turn of the centuries, YRD development is listed in the two major projects in the new century by Shandong provincial government. According to the plan, YRD will become an important energy, chemical and agricultural production base in 15-20 years. In view of its location and natural conditions, so far there exist a lot of environmental problems in YRD. Thus the principle of economic development coordinating with environmental protection must be implemented during YRD development. Forestation is one of the vital measures to cope with environment degradation. Therefore, strategies of forestry development and techniques of tree planting in different land use types are discussed in the paper based on site classification with specific problems involved .展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.41006024)Marine Specific Research for Public‘Forecast and appraisal for geologic hazard of inshore seafloor and study of key technology for protection’(Grant No.201005005)
文摘The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipe- line located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which in- eluded a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage （MFL） sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage （MFL） detection results also reveal the possible connec- tion between long free spans and accelerated corrosion of the pipeline.
基金The research is funded by State Tenth Five-year Plan of Science & Technology Project (2004BA516A13)
文摘The Yellow River Delta (YRD) is one of the biggest deltas that have not been developed in the world. During the turn of the centuries, YRD development is listed in the two major projects in the new century by Shandong provincial government. According to the plan, YRD will become an important energy, chemical and agricultural production base in 15-20 years. In view of its location and natural conditions, so far there exist a lot of environmental problems in YRD. Thus the principle of economic development coordinating with environmental protection must be implemented during YRD development. Forestation is one of the vital measures to cope with environment degradation. Therefore, strategies of forestry development and techniques of tree planting in different land use types are discussed in the paper based on site classification with specific problems involved .
