The topside floatover installation is always a great challenge and is sensitive to environmental conditions.In this study,experimental analysis on the mating operation of the floatover installation in different wave h...The topside floatover installation is always a great challenge and is sensitive to environmental conditions.In this study,experimental analysis on the mating operation of the floatover installation in different wave headings is presented.The continuous mating operation using the rapid transfer technique was experimentally simulated with the assistance of the jacking system and the ballast system.In the continuous transfer modeling,the topsides loads were transferred onto the jacket by several consecutive steps,including the first rapid jack-down for the 30%loads,continuous 30%−70%load transfer and the second repaid jack-down for the remaining 30%loads.Motions of the barge and the topsides as well as loads on the Deck Support Unite(DSU)and the Leg Mating Unite(LMU)in different wave headings were measured.Experimental results illustrated the complex motion behavior and load characteristics of the continuous transfer operation.Results indicate that the rapid jack-down operations will lead to impact loads and larger lateral DSU loads.The bow quartering seas are much more dangerous as it gives rise to the larger motions and loads.Comparisons with the traditional steady-state modeling indicate that the continuous transfer modeling has greater advantages over the steady-state modeling on predicting the loads.展开更多
In this study,Qilian Mountain active source airgun signals recorded at 79 stations were obtained after stacking waveforms from July 2015 to December 2016.Based on analysis of the amplitude variation characteristics of...In this study,Qilian Mountain active source airgun signals recorded at 79 stations were obtained after stacking waveforms from July 2015 to December 2016.Based on analysis of the amplitude variation characteristics of the airgun signals,the following conclusions were drawn:along the NW-SE fault distribution direction of the Qilian Mountain area,the decrease in amplitude of airgun signals was relatively slow in relation to the epicentral distance,while the decrease in amplitude in the direction perpendicular to the fault was relatively fast.This difference may be related to the energy loss of seismic waves reflecting and scattering by the regional faults mainly distributed along the NW-SE direction,which are caused by tectonic compression of the QinghaiTibet and Alxa blocks.展开更多
文摘The topside floatover installation is always a great challenge and is sensitive to environmental conditions.In this study,experimental analysis on the mating operation of the floatover installation in different wave headings is presented.The continuous mating operation using the rapid transfer technique was experimentally simulated with the assistance of the jacking system and the ballast system.In the continuous transfer modeling,the topsides loads were transferred onto the jacket by several consecutive steps,including the first rapid jack-down for the 30%loads,continuous 30%−70%load transfer and the second repaid jack-down for the remaining 30%loads.Motions of the barge and the topsides as well as loads on the Deck Support Unite(DSU)and the Leg Mating Unite(LMU)in different wave headings were measured.Experimental results illustrated the complex motion behavior and load characteristics of the continuous transfer operation.Results indicate that the rapid jack-down operations will lead to impact loads and larger lateral DSU loads.The bow quartering seas are much more dangerous as it gives rise to the larger motions and loads.Comparisons with the traditional steady-state modeling indicate that the continuous transfer modeling has greater advantages over the steady-state modeling on predicting the loads.
基金the National Key Research and Development Project(No.2018YFC1503206)the National Natural Science Foundation of China(No.41674046).
文摘In this study,Qilian Mountain active source airgun signals recorded at 79 stations were obtained after stacking waveforms from July 2015 to December 2016.Based on analysis of the amplitude variation characteristics of the airgun signals,the following conclusions were drawn:along the NW-SE fault distribution direction of the Qilian Mountain area,the decrease in amplitude of airgun signals was relatively slow in relation to the epicentral distance,while the decrease in amplitude in the direction perpendicular to the fault was relatively fast.This difference may be related to the energy loss of seismic waves reflecting and scattering by the regional faults mainly distributed along the NW-SE direction,which are caused by tectonic compression of the QinghaiTibet and Alxa blocks.
