The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mi...The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mill Office.The copresence of a banquet scene of the Northern Song dynasty’s scholar-officials and a water mill both suggests a realistic reproduction of a specific scene and indicates the significance of the water mill as a cultural space.The Northern Song dynasty’s government-operated water mills were especially noticeable in the Capital Circuit京畿路,whose center was Dongjing东京.The basic development path of government-operated water mills in the inner and outer city of Dongjing was first from grain processing,which supplied the needs of the imperial palace,to tea processing,in which the governmental commercial capital also participated.Regarding city space and the use of water sources,the development spread from the north of the city to the south.Other prefectures outside Dongjing also had government-operated water mills—some brought income that could be used as official fiscal expenditure,including military expenditure,and were used to satisfy the need of local people’s livelihood,while some were used to serve the monopoly policy of tea and demonstrate the benevolent governance of local officials.In the Northern Song dynasty,the water mill was no longer merely a production site;rather,it was also a cultural space that integrated a natural background and artificial ingenuity.Closely related to the hosting of emperors and the garden making,sightseeing,feasting,and drinking of scholar-officials,along with the festival activities of locals,the water mill in the Northern Song dynasty was of great cultural significance.展开更多
The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, Chi...The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition.展开更多
Serious sediment deposition often occurs after the construction of tidal sluices in small or medium-sized tidal muddy estuaries, so desilting or dredging is needed to meet the demands of flood discharge, saltwater ret...Serious sediment deposition often occurs after the construction of tidal sluices in small or medium-sized tidal muddy estuaries, so desilting or dredging is needed to meet the demands of flood discharge, saltwater retaining, and navigation in those areas. In this paper, the problem of sediment deposition induced by construction of tidal sluices is analyzed. Different problems of silting near tidal sluices for different types of estuaries are summed up, at the same time, corresponding methods are given to solve these problems, and a few successful examples are also given. The idea of comprehensive regulation and utilization of estuaries is put forward, and some proposals for solution of sediment deposition in this kind of estuaries are made.展开更多
This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different disc...This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different discharges from (6.2 to 18.15) l/s and five different gate cases (vertical and inclined vertically) by angle (45)° with and opposite flow direction with horizontal and sharp lower lip. The values of coefficients of contraction (Cc) and discharge (Cd) increases when gate slope increases with flow direction and the lower lip is horizontal, these increases are (16)% and (18)% respecttively, while these values decreases when gate slope increases opposite flow direction and the lower lip is horizontal these decreases are (13)% and (11)% respectively. The values of coefficient of velocity (Cv) remain constant and don’t effect with changes of gate slope or gate lip.展开更多
In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asym...In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral sides.The corresponding inflow Froude number is allowed to range in the interval(1.40<F1<6.11).The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered flume.For F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels.Also,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.展开更多
In the process of water conservancy project sluice construction, it is relatively easy to be affected by some external factors, which will cause serious harm to the sluice project construction. Therefore, in the proce...In the process of water conservancy project sluice construction, it is relatively easy to be affected by some external factors, which will cause serious harm to the sluice project construction. Therefore, in the process of sluice construction, it is necessary to select the appropriate sluice construction scheme and technical measures according to the actual situation of water conservancy project construction, and at the same time, based on the overall characteristics of water conservancy project construction, analyze the sluice construction technology in detail, so as to improve the quality of sluice construction, guarantee the construction progress and quality, and promote the effective development of water conservancy project sluice construction.展开更多
In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably ca...In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably cause serious consequences to the whole project, and will also cause some potential safety hazards to the downstream area. More seriously, it will cause the lives and property of the residents to be threatened, thus causing serious economic losses and seriously hindering the development of society. In order to solve this problem, we must do a good job in the reinforcement design of water conservancy projects, carry out a comprehensive design of the reinforcement work of the sluice in strict accordance with various engineering standards, and ensure the smooth progress of water conservancy projects.展开更多
文摘The Sluice Gate with Freight Carts is the earliest extant scroll in China that depicted a water mill.It was drawn during the early or middle Northern Song dynasty and was possibly a true portrayal of the West Water Mill Office.The copresence of a banquet scene of the Northern Song dynasty’s scholar-officials and a water mill both suggests a realistic reproduction of a specific scene and indicates the significance of the water mill as a cultural space.The Northern Song dynasty’s government-operated water mills were especially noticeable in the Capital Circuit京畿路,whose center was Dongjing东京.The basic development path of government-operated water mills in the inner and outer city of Dongjing was first from grain processing,which supplied the needs of the imperial palace,to tea processing,in which the governmental commercial capital also participated.Regarding city space and the use of water sources,the development spread from the north of the city to the south.Other prefectures outside Dongjing also had government-operated water mills—some brought income that could be used as official fiscal expenditure,including military expenditure,and were used to satisfy the need of local people’s livelihood,while some were used to serve the monopoly policy of tea and demonstrate the benevolent governance of local officials.In the Northern Song dynasty,the water mill was no longer merely a production site;rather,it was also a cultural space that integrated a natural background and artificial ingenuity.Closely related to the hosting of emperors and the garden making,sightseeing,feasting,and drinking of scholar-officials,along with the festival activities of locals,the water mill in the Northern Song dynasty was of great cultural significance.
文摘The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition.
文摘Serious sediment deposition often occurs after the construction of tidal sluices in small or medium-sized tidal muddy estuaries, so desilting or dredging is needed to meet the demands of flood discharge, saltwater retaining, and navigation in those areas. In this paper, the problem of sediment deposition induced by construction of tidal sluices is analyzed. Different problems of silting near tidal sluices for different types of estuaries are summed up, at the same time, corresponding methods are given to solve these problems, and a few successful examples are also given. The idea of comprehensive regulation and utilization of estuaries is put forward, and some proposals for solution of sediment deposition in this kind of estuaries are made.
文摘This paper present the effect of the lower gate lip on the coefficient of contraction, velocity and discharge which have been made in a rectangular flume with four gates opening from (2 to 4.5) cm, five different discharges from (6.2 to 18.15) l/s and five different gate cases (vertical and inclined vertically) by angle (45)° with and opposite flow direction with horizontal and sharp lower lip. The values of coefficients of contraction (Cc) and discharge (Cd) increases when gate slope increases with flow direction and the lower lip is horizontal, these increases are (16)% and (18)% respecttively, while these values decreases when gate slope increases opposite flow direction and the lower lip is horizontal these decreases are (13)% and (11)% respectively. The values of coefficient of velocity (Cv) remain constant and don’t effect with changes of gate slope or gate lip.
文摘In this study,the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally,including the so-called sequent depths,characteristic lengths,and efficiency.In particular,an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered,with the bottom of the flume transversely inclined at an angle of m=0.296 and vertical lateral sides.The corresponding inflow Froude number is allowed to range in the interval(1.40<F1<6.11).The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections.A relationship for calculating hydraulic jump efficiency is proposed for the considered flume.For F1>5,the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels.Also,when■mes>8 and■>5,the hydraulic jump in the asymmetrical trapezoidal channel downstream of a parallelogram sluice gate is completely formed as opposed to the situation where a triangular sluice is considered.
文摘In the process of water conservancy project sluice construction, it is relatively easy to be affected by some external factors, which will cause serious harm to the sluice project construction. Therefore, in the process of sluice construction, it is necessary to select the appropriate sluice construction scheme and technical measures according to the actual situation of water conservancy project construction, and at the same time, based on the overall characteristics of water conservancy project construction, analyze the sluice construction technology in detail, so as to improve the quality of sluice construction, guarantee the construction progress and quality, and promote the effective development of water conservancy project sluice construction.
文摘In the concrete water conservancy construction, the sluice is widely used in various water conservancy projects, which has irreplaceable significance. If there is a certain problem in the sluice, it will inevitably cause serious consequences to the whole project, and will also cause some potential safety hazards to the downstream area. More seriously, it will cause the lives and property of the residents to be threatened, thus causing serious economic losses and seriously hindering the development of society. In order to solve this problem, we must do a good job in the reinforcement design of water conservancy projects, carry out a comprehensive design of the reinforcement work of the sluice in strict accordance with various engineering standards, and ensure the smooth progress of water conservancy projects.
