One of the most important issues in geotechnical engineering is excess pore pressure caused by clay soil loading and consolidation. Regarding uncertainties and complexities, this issue has long been the subject of att...One of the most important issues in geotechnical engineering is excess pore pressure caused by clay soil loading and consolidation. Regarding uncertainties and complexities, this issue has long been the subject of attention of many researchers. In this work, a one-dimensional consolidation apparatus was equipped in a way that pore water pressure and settlement could be continuously read and recorded during consolidation process under static loading. The end of primary consolidation was obtained using water pressure changes helping to present a new method for determining the end of primary consolidation and consolidation coefficient. This method was then compared with two classical theory methods of lg t and t. Using Terzaghi's theory, the way of pore pressure dissipation for lg t, t and the new method was found and compared with experimental results. It is concluded that the new method has better results.展开更多
With the deepened transformation of China＇s power system, the stability and reliability of power utilization have been dramatically improved, but meter reading data acquisition does not keep pace with the times. With...With the deepened transformation of China＇s power system, the stability and reliability of power utilization have been dramatically improved, but meter reading data acquisition does not keep pace with the times. With the continuous maturity of low-voltage power line communication （PLC）, this leads us to see hopes of using PLC technology to realize remote meter reading. In this paper, based on current PLC technology and combining domestic and foreign successful cases, a beneficial exploration and research is conducted from the composition and establishment of software and the design of software and protocol.展开更多
Wind loading is one of the most significant factors in civil engineering that influences the structural design considerably.In this paper,a group of manufacturing equipments for downburst simulation based on impinging...Wind loading is one of the most significant factors in civil engineering that influences the structural design considerably.In this paper,a group of manufacturing equipments for downburst simulation based on impinging jet model was developed for investigating the wind loads on structures:including the centrifugal air bellows to generate airflow,a movable platform to realize multiple locations of the building and a freely rotatable turntable to implement alterable building angles.Hundreds of transducers were used to measure the wind action on all surfaces of the building.The pressure coefficients calculated from the observed data were utilized to evaluate the downburst wind load.Pressure distributions on three prism-shaped building models with different placements and angles were investigated to obtain the maximum wind action and mean pressure coefficients.The results showed that the maximum pressure coefficient would reach 1.0 on the top surface if the downburst just broke out over the edifice.Considering that the building was in the developing field of the downburst,the top and the front surfaces would be under high wind pressure and only the back surface would endure wind suction.When the downdraft happens away from the prismatic building,all surfaces,except the front surface,would subject to suction with different degrees.It was also found that the pressure coefficient on the right surface would get its negative peak at first and then go straight up to 0.6 as the angle changed from 0°to 45°and the wind pressure on the front surface would decrease slightly through the whole process.The assertive results provide elemental data for structural wind-resistant design in civil engineering for the downburst-prone areas.展开更多
Separated flow can be effectively controlled through the management of blade boundary layer development.Numerical simulations on a highly-loaded,low-solidity compressor cascade indicate that combined blowing and sucti...Separated flow can be effectively controlled through the management of blade boundary layer development.Numerical simulations on a highly-loaded,low-solidity compressor cascade indicate that combined blowing and suction flow control technique can significantly improve cascade performance,especially in increasing the cascade loading and static pressure ratio as well as decreasing the loss coefficient.Meanwhile,it is more effective to improve cascade performance by blowing near leading edge on suction surface than suction near trailing edge.Both the locations and flow rates of blowing and suction are major impact factors of this method to cascade performance.Comparing to the baseline,the static pressure ratio increases by 15% and loss coefficient decreases by 80%,with a blowing fraction of 1.7% and a suction fraction of 1.38% of the inlet mass flow.展开更多
文摘One of the most important issues in geotechnical engineering is excess pore pressure caused by clay soil loading and consolidation. Regarding uncertainties and complexities, this issue has long been the subject of attention of many researchers. In this work, a one-dimensional consolidation apparatus was equipped in a way that pore water pressure and settlement could be continuously read and recorded during consolidation process under static loading. The end of primary consolidation was obtained using water pressure changes helping to present a new method for determining the end of primary consolidation and consolidation coefficient. This method was then compared with two classical theory methods of lg t and t. Using Terzaghi's theory, the way of pore pressure dissipation for lg t, t and the new method was found and compared with experimental results. It is concluded that the new method has better results.
文摘With the deepened transformation of China＇s power system, the stability and reliability of power utilization have been dramatically improved, but meter reading data acquisition does not keep pace with the times. With the continuous maturity of low-voltage power line communication （PLC）, this leads us to see hopes of using PLC technology to realize remote meter reading. In this paper, based on current PLC technology and combining domestic and foreign successful cases, a beneficial exploration and research is conducted from the composition and establishment of software and the design of software and protocol.
基金supported by the National Natural Science Foundation of China(Grant No.51161120359)
文摘Wind loading is one of the most significant factors in civil engineering that influences the structural design considerably.In this paper,a group of manufacturing equipments for downburst simulation based on impinging jet model was developed for investigating the wind loads on structures:including the centrifugal air bellows to generate airflow,a movable platform to realize multiple locations of the building and a freely rotatable turntable to implement alterable building angles.Hundreds of transducers were used to measure the wind action on all surfaces of the building.The pressure coefficients calculated from the observed data were utilized to evaluate the downburst wind load.Pressure distributions on three prism-shaped building models with different placements and angles were investigated to obtain the maximum wind action and mean pressure coefficients.The results showed that the maximum pressure coefficient would reach 1.0 on the top surface if the downburst just broke out over the edifice.Considering that the building was in the developing field of the downburst,the top and the front surfaces would be under high wind pressure and only the back surface would endure wind suction.When the downdraft happens away from the prismatic building,all surfaces,except the front surface,would subject to suction with different degrees.It was also found that the pressure coefficient on the right surface would get its negative peak at first and then go straight up to 0.6 as the angle changed from 0°to 45°and the wind pressure on the front surface would decrease slightly through the whole process.The assertive results provide elemental data for structural wind-resistant design in civil engineering for the downburst-prone areas.
基金support from the National Natural Science Foundation of China as part of the Free Application Project (No.50776003)supported and funded by the Key Program of Aviation Science Foundation,Grant No.2007ZB51018
文摘Separated flow can be effectively controlled through the management of blade boundary layer development.Numerical simulations on a highly-loaded,low-solidity compressor cascade indicate that combined blowing and suction flow control technique can significantly improve cascade performance,especially in increasing the cascade loading and static pressure ratio as well as decreasing the loss coefficient.Meanwhile,it is more effective to improve cascade performance by blowing near leading edge on suction surface than suction near trailing edge.Both the locations and flow rates of blowing and suction are major impact factors of this method to cascade performance.Comparing to the baseline,the static pressure ratio increases by 15% and loss coefficient decreases by 80%,with a blowing fraction of 1.7% and a suction fraction of 1.38% of the inlet mass flow.
