Abstract:Based on a comprehensive analysis including case analysis , theoretical analysis, river regime analysis and tidal current mathematical model research, regulation parameters such as water level, bending rate and river widening rate are determined. In the service of existing channel plan objectives and channel function positioning, we research the phased regulation scheme and regulation line of the Yangtze River estuary waterway regulation project, which may guide the waterway construction during the planning period. The research results play a supporting role on the compilation of Waterway Ddevelopment Plan for the Yangtze Estuary.

Abstract:The Yangtze estuary is located in the most economically developed regions of China. It’s the golden waterway of the Yangtze River. With the rapid development of port throughput and economy, the shortage of land resources promoted wharf dredging and mining industry. Pursuing the maximum profit, small engineering ships carried out illegal operation such as throwing mud and sand from time to time, which destroyed the normal competition order and damaged the environment and channel conditions. So, it’s urgent for the government to strengthen management and curb the spread of illegal behaviors. Based on several years of practice, this paper summarizes the way of improving law enforcement supervision of small engineering ships in the Yangtze River estuary, which can be used for scholars and government departments to make better decisions.

Abstract:Due to high development intensity of port and waterway resources in the Yangtze River estuary, the generated quantity of dredged materials is large, and dredged materials’ disposal has become a major technical problem in the field of port and waterway engineering. Using lots of engineering field data, we analyze the source, quantity and properties of dredged material of Yangtze Estuary, summarize the current situation and main problems, and discuss the future outlets of dredged materials generated from the Yangtze estuary. The results show that the annual average quantity of dredged materials is nearly 100 million square meters, which is generated mainly from the 12.5-meter-deep waterway of the South Channel and North Passage of the Yangtze estuary and secondary channel of Waigaoqiao port area phase four to six project of Shanghai port. At the present stage, the dredged materials are still mainly dumped to ocean dumping sites, the ratio of resource utilization is not high generally, and its use pattern is relatively simple. Under the background of more stringent ocean dumping management and more popular lowcarbon circular economy, the fundamental outlet of dredged material disposal of Yangtze estuary lies in higher level of multiply resource utilization, effective engineering measures for port and waterway sedimentation reduction, and strengthening assessment and rational use of ocean dumping sites.

Abstract:The dredged soil is gradually becoming the effective supplement of sediment resource in the Yangtze estuary. Since the tidal flat reclamation project behind Changxing submerged breakwater is adjacent to the deepwater channel of 12.5 m in South Channel of the Yangtze estuary, the utilization of dredged soil in channel has a significant advantage in geographic location. Based on the investigation of the dredged soil conditions, according to the characteristics of the reclamation project, this article selects the suitable dredging and filling process, and puts forward the feasible technical scheme. The results show that the deepwater channel dredged soil in the section of South Channel to Yuanyuan shoal has the characteristics of abundant and stable production, short transportation distance, and good condition of soil texture, which can satisfy the requirements of sediment in the reclamation project. In all kinds of dredging and filling process, bow-blowing technology and trailing suction hopper dredger (TSHD) loading barge technology have well applicability in the project. The bow-blowing technology is mature, and can be applied. And the TSHD loading barge technology as an alternative can be used when putting into operation formally at the end of 2013. The research results reveal the sediment resource for the tidal flat reclamation project, and achieve a win-win situation of channel dredging the channel and land reclamation.

Abstract:The Yangtze estuary regime changes frequently and it’s easily influenced by natural and human factors. Illegal dumping causes not only local variation of channel topography, but also local siltation of the channel. This will affect seriously the navigation safety and increase the channel maintenance cost and destroy the channel resources. From the view of channel development and channel resources protection, it is necessary to strengthen the supervision and reduce human influence on the channel of the Yangtze estuary as possible as we can.

Abstract:According to the VTS and AIS ship navigation data records, this paper uses software of trajectory analysis and flow statistics to analyze the ship traffic, shipping and the actual ship draft during different periods of construction of the Yangtze estuary deepwater channel. It can provide the computation basis for calculating the shipping economic benefit from the construction of the deepwater channel.

Abstract:Following completion of the Yangtze estuary deep-water channel, the importance of maintenance and management becomes highlights. Informatization construction can further improve the working efficiency, providing a solid information base for the channel depth. This paper introduces the characteristics and necessity of digital information construction in the Yangtze estuary. According to the demand of the construction, this paper puts forward some preliminary idea of the target and framework of digital information construction of the Yangtze estuary. The results show that the Yangtze estuary digital information construction should contain the maintenance and management of waterway, waterway administrative management, asset management, channel intelligent monitoring, underwater terrain, dynamic monitoring of foreign information service. The general goal of Yangtze estuary digital information construction is building three big platform frameworks and two systems.

Abstract:This paper introduces the application of GPS key technology in the Yangtze estuary deepwater channel regulation project, including the establishment of GPS control network, height anomaly network construction, no tide topography measurement. This technology has been applied successfully to each procedure of port and waterway engineering construction, and has been widely used in China.

Abstract:Dumped sediment transport at the dredge disposal site in the north passage of the Yangtze estuary is studied by field measurement. The volume of dredge disposal zone is obtained by multi-beam sonar. The density of surface is measured by sampler-collection and the density of different level is measured by stationary-piston sampler. The sediment loss ratio from the disposal zone can be calculated by the volume of dredge disposal zone and the total disposal dredge of the self-propelled trailing suction hopper dredgers. The result shows that the sediment loss ratio is about 76%. The flow velocity obtained by flow-measure- system is so big that much sediment can be carried out of the disposal zone, which can be used to explain the sediment loss ratio. The location of dredge disposal zone should be moved to the middle section of dams for reducing the sediment loss ration.

Abstract:Based on the hydrologic data of the Yangtze estuary 12.5 m deepwater channel in the flood season and dry season, we analyze the spatial and temporal distribution of suspended sediment concentration. The result reveals that suspended sediment concentration in the south channel & Yuanyuansha and the middle section of the north passage is small, and its vertical distribution is relatively uniform. But in the middle section of the north passage, the suspended sediment concentration is high and the vertical distribution is uneven. Fine sediment flocculation, fresh and salt water mixing and stagnation point may be the main reasons for the high suspended sediment concentration in the bottom of the middle section of the north passage and large differences in the vertical distribution of the flood season. The high suspended sediment concentration in the middle section of the north passage and in the flood season is consistent with the characteristic of temporal and spatial change of 12.5 m deepwater channel siltation, indicating that siltation in the north passage resulting from the suspended sediment’s deposition. The suspended sediment concentration in the south channel & Yuanyuansha is significantly lower than that in the north channel, and the vertical distribution is relatively uniform, which indicates that the contribution of channel siltation from suspended sediment silting may be small.

Abstract:Using the observation data of fluid mud after three huge stormy waves in the Yangtze estuary, we analyze the development, transportation and dissipation process of the fluid mud in 12.5-meter deepwater channel The results show that the fluid mud in the channel develops clearly after huge stormy waves in the flood season. Its maximum thickness can reach about 3.5 to 3.8 meters and the volume can reach about 27 million cubic meters. The scale of fluid mud’s development relates to the duration of stormy waves and the tidal regime during stormy waves. The longer the stormy waves continue, the larger the fluid mud develops. And when the stormy waves meet the spring tide, the large-scale fluid mud can be formed; When the stormy waves meet the neap tide, the scale of fluid mud is smaller relatively. Fluid mud mainly develops in 12.5-meter channel, and there is little fluid mud on the riverbed of both sides of the channel. After the fluid mud is formed, it will move up and down in the channel under the effect of tidal current, with an amplitude of fluctuation about 13~18 kilometers. The fluid mud formed in the spring tide will migrate upward as a whole during the following neap tide. Fluid mud in deepwater channel exits about 5~10 days, and the dissipation of fluid mud is mainly connected with the enhancement of tide power. The fluid mud formed after stormy waves will disappear gradually with the subsequent spring tides.

Abstract:According to data from 11 tidal stations of the Yangtze estuary, this paper analyzes the mean high tide, mean low tide and mean sea level of each station from 1996 to 2011, and finds the recent change of tidal characteristics in the Yangtze estuary, analyzes related factors, discusses the reasons of recent changes of tidal characteristics in the Yangtze estuary. The results show that the mean sea level of each tidal station rises a little bit. The basin’s runoff change seems no influence on the estuarine tidal characteristic value. Global warming has some effect on the mean sea level change in the long term, but it has little impact in the short term. It is affected by the engineering construction of the Yangtze estuary in recent years, which shows that the mean high tide level is going down, the average low tide is rising, the tidal range is decreasing, the flood time is shortened, the ebb time is extended, and the annual lowest tide is rising. The Yangtze estuary is influenced by the runoff, tidal current and engineering construction, and the tide’s characteristic value changes along the way are also different, so we should pay more attention to the estuarine engineering design, flood control and river estuary management, etc.

Abstract:It is the first time that the bottom tripod survey system is deployed in Tongzhousha reach of the Yangtze River for the purpose of studying the existing water and sediment characteristics and near bottom sediment transportation conditions during flood and dry seasons of this reach. The field data shows that the distribution of velocity is ebb tide > flood tide, deep channel ≥ high shoal > low shoal during flood tide, deep channel ≥ low shoal > high shoal during the ebb tide and spring tide > middle tide > neap tide. There is a good linear correlation between the mean velocity of flood or ebb tide and tide range with the correlation coefficient above 0.9. The distribution of SSC near bottom is ebb tide > flood tide, deep channel > low shoal > high shoal and spring tide > middle tide > neap tide. SSC during the flood season is about 1~1.5 times bigger than that during the dry season. The correlation coefficient between near bottom SSC and dimensionless coefficient v2/(gh) is about 0.5 during the dry season and about 0.6~0.7 during the flood season, a series of formula based on this correlation can be used to estimate the near bed sediment transport capacity of the Tongzhousha reach.

Abstract:The hydrological observations in both spring and neap tides are carried out in February and August respectively. Based on these data , this paper studies the changing characteristics of water , sediment and salinity from the south channel to the north passage. Conclusions are drawn as follows: 1) The ebb tide duration is longer in the flood season while the rise tide duration is longer in the dry season on the whole. 2) The average flow velocity of the ebb tide is generally bigger in the flood season while the flood current speed is generally bigger in the dry season. During the period of neap tide, there exists the phenomenon that the average velocity of the flood tide near the bottom is bigger than the surface. 3) The value and vertical difference of sediment is larger in the flood season from midstream of the north channel to the water area outside. From the south channel to the upper reach of the north channel, the value of sediment is larger in the dry season. 4) There exists saltwater wedge in the midstream of the north channel which is upper in the dry season.

Abstract:Considering the sediment difference during the flood tide and the ebb tide, two formula deduced from the viewpoint of energy balance, for suspended sediment carrying in the Yangshan harbor of each flood and ebb tide are established. The suspended sediment carrying is calculated from the equation that the formula evaluating the bottom sediment flux by shear stress equals the formula by suspended sediment carrying. The observed data at the Yangshan harbor in October of 2003 is taken to calibrate the coefficients of the formula for suspended sediment carrying. Finally, the formula is verified by the measured data of suspended sediment concentration in the Yangshan harbor in July of 2005. The result shows that the established formula for suspended sediment carrying in the Yangshan harbor has a high precision. The calculated sediment concentration is in agreement with the measured ones.

Abstract:In view of two obstacle segments of navigation channel from Taicang to Nantong named TZS (Tongzhou shoal) waterway and BMS (Baimao shoal) waterway, the first phase project of 12.5 m deep-water navigation channel project was designed and now is under building, aiming at extending from Taicang to Nantong port. In order to study project effects, movable bed physical model is designed to optimize the project layout by comparing normal-rainfall-sedimentation-two-years and rich-rainfall-sedimentation-year conditions. TZS subproject has obvious effect to prevent shoal erosion, training dike and tooth groins can prevent washing back of the left edge of TZS and LSS (Langshan shoal), and the erosion development process of scour channel between TZS and LSS can also be prevented. The navigation condition of deep water channel in the East LSS waterway can be improved. BMS sub-project also has obvious effects to prevent shoal erosion as well as to change the backward trend of shoal caused by erosion. Also, small sand bar locating in south channel of BMS which cause navigation obstruction was also significantly eroded due to the projects, navigation condition of the inlet section of south channel of BMS was also improved. Conclusions can be drawn from the study that no obvious difference can be seen between the tests under normal-rainfall-sedimentation-two-years condition and rich-rainfall-sedimentation-year condition. Overall,the project can achieve the goal of engineering construction.

Abstract:In order to study the relationship between Nanhui beach reclamation and beach sedimentation transportation on the top of Jiuduansha shoal as well as sediment transportation crossing the south training dike of the Yangtze estuary deep-water channel engineering, comparative experiments of fixed bed sediment transport before and after the reclamation are made on the Yangtze estuary model. The cross dike sediment transportation along with sediment incipient motion along Jiuduansha shoal is studied, then according to the bottom sediment distribution in the north passage, the influence on the deep-water channel in the north passage caused by the reclamation can be analyzed. The study shows that the bottom sediment of Jiuduansha shoal can be transported crossing the south training dike into the deep-water channel with or without reclamation. When the reclamation is executed, less sediment of the head part of Jiuduansha shoal is transported into the channel in the north passage, but mort sediment of the medium part of Jiuduansha shoal is transported into channel.

Abstract:Based on the test data, the engineering measures to enhance the flow erosion capability in the north passage of the Yangtze estuary are discussed. The results shows that: 1) It is not feasible for attempting to adjust the topography in the middle region of the north passage to make natural thalweg location coincident with the current navigation channel axis by dike construction project only; 2)To achieve a more obvious erosion effect, the new dike should be arranged in the deep water near the mainstream, in addition, groyne encryption also plays a significant role in the north side of the north passage, middle region; 3) To further enhance the flow erosion capability in the north passage, the comprehensive measures of adjusting new groyne and navigation axis should be taken. It is difficult to better enhance the flow erosion capability in the north passage by extending groyne only.

Abstract:The local normal physical model is adopted to study the local scour (problems) on project in the tidal estuary for the first time. The results show that: 1) It is feasible to apply the local normal physical model to study the engineering problems in the tidal estuary; 2) Choice of the test hydraulic conditions, determination of model boundary condition and entire variable slope of the model are the key techniques to apply the local normal physical model to the engineering problems in the tidal estuary; 3) A simple and feasible method to determine model boundary condition is presented; 4) The necessity and method of applying entire variable slope of the model are expounded.

Abstract:For coastal and estuarine morphdynamics, consolidation of fine sediment is of crucial importance for us to understand its influence on sediment dynamics process. Based on a new settling column and the DensiTune, three series of consolidation experiments are carried out, the difference between those series is the median grain size, all the sediment samples are collected originally from the Yangtze estuary. Two methods, the density method and the McLaughlin method, are employed to calculate the consolidation velocity. Experiments have shown that the flocculation becomes weaker when sediment size increases, and we find that the grain size is a significant impact for fine sediment consolidation. According to careful analysis and comparison, the consolidation velocity of fine sediment in the Yangtze estuary is in the range of 0.31×10-3~4.8×10-3 mm/s.

Abstract:The inlet river of the south channel and north channel is one of those with the most frequent change in the Yangtze estuary. Based on the analysis of river bed evolution and control effect of the south and north channel inlet project, this paper probes into the riverbed evolution trendy and further regulation strategy under new situation. The result shows that under the new situation, the inlet river of the south channel and north channel is still characterized with unstable factors, featuring especially the uncontrolled Biandan bar and the increasing impact-resistant brush pressure of regulation buildings. The regulation scheme proposed countering the unstable factors is proved effective and feasible by the tidal current mathematical model research.

Abstract:Taking the north passage of the Yangtze River estuary for example and based on a large number of field measured data, we analyze the flow dynamics characteristics and evolution characteristics on the wide-shallow tidal estuary meandering river and explore the relationship between the fact of silting concentration in the bend section of the north channel and the evolution of wide-shallow tidal estuary meandering river. The result shows that despite the disturbance of multiple factors and the strong two-dimensional characteristics of the channel, the tidal estuary meandering river still presents bend flow characteristics and characteristics of evolution to a certain degree. The bend on the middle north channel may promote silting concentration.

Abstract:The evolution of the river regime in the north passage after the construction of the second phase of the Yangtze River deepwater navigation channel project from 2004 to 2007 is analyzed. The results show that the principle of “deposit in flood season while erosion in dry season” applies generally to the mouth bar zone of the north passage. Besides, the north beach of the upstream of the north passage deposits all the time. Deposition also happens on the south beach near W3, which leads to a high slope of the shoal. In addition, the nonlinear negative correlation effect between the depth ratio of the south shoal channel and the channel siltation volume is significantly strong. Several reasons can be concluded to explain the high siltation volume in the navigation channel, such as the continuous deposition at the W3 south beach, small depth ratio of the shoal channel, high slope of the beach and the fact that the width of the 8m-depth line is the smallest.

Abstract:FJS (Fujiangsha) section of the Yangtze estuary with braided shoals distributed in the channel, is a complicated and bifurcated plain river. River bed nearby, impacted by runoff and current flows, is divided at the wide river sections. The main passage is bifurcated and the 12.5 m deep contour breaks at many navigation sections. So FJS section becomes an obstructed river for vessels sailing. The Ministry of Transport intends to implement construction of 12.5 m deep-water navigation channel under Nanjing during the “Twelfth Five-Year Plan” period. The principle of the control project is “Following river evolution; Keeping originally as bifurcated; Protecting SJS (Shuangjiansha) shoal; Stabilizing the navigation channel”. Based on the measured data, we analyze the river regime evolution. The results show that: 1) With the cyclical change of the hydrological year, sand bodies and inlets will be replaced by each other over and over again which has negative impact on the navigation stability so that there is great necessity of SJS shoal protection project; 2) Due to the restriction of shore lines, navigation channels in Fubei and Funan waters stay stable, besides, the depth can be deepen to 12.5 m contour by dredging measures while the width of the passage cannot be guaranteed; 3) According to the river regime evolution, Fuzhong passage, with a wide main channel and a moderate turning curvature, has a trend of erosion which is to make a better navigation condition.

Abstract:2-D tidal and sediment numerical model with triangular grids is set up to study the general planning scheme of Tonghai harbor area at Nantong port based on the Yangtze estuary waterway maintenance management platform “ SWEM2D / 3D”. According to the simulation results, the impacts of the general planning scheme on the nearby main waterways( main channel of Yangtze, Baimao channel, Beizhi channel, Xinkasha channel and Fushan channel) are analyzed. The numerical simulation result shows that current on the Xuliujing section is further strengthened after the implementation of the general planning scheme. The impact scope of the general planning scheme is about 1.5 km away from the harbor. The affect of wharf engineering to Sutong bridge is very small, and its main navigable hole will keep stable. The general planning scheme of Tonghai harbor area has little influence on the tidal force in the nearby main waterways, and the general planning scheme is feasible.

Abstract:Based on the Rouse formula, the suspended sediment characteristics of vertical distribution is studied and analyzed by data measured and collected in the Yangtze estuary, and the applicability of the formula Rouse is verified. The difference between the settling velocity of sediment calculated by Rouse formula and the actual sediment settling velocity is clarified. Using the sediment vertical distribution of measured data in the north channel, the relationship of the unbalanced empirical formula of sediment coefficient and vertical average sediment concentration is established, based on which, an empirical formula of vertical distribution of suspended sediment is established and verified by measured data.

Abstract:The tidal current fields of the Yangtze estuary with different topography, different projects and different runoff are simulated. The amount of the flood current, ebb current and the net water leak with different tidal stencils and different runoff is counted and analyzed. And the amount of the flood current, ebb current and the net water leak before the implementation of the deepwater channel project and after completion of the deepwater channel phase II project is counted and analyzed.

Abstract:In order to study the wave condition on sheltered waters behind permeable hydraulic structures, we simulate the wave propagation under given conditions using both the BW (Boussinesq wave) module of the MIKE 21 (DHI) and the SWAN model. Through the comparison between the two sets of numerical simulation results and three dimensional physical model results, we analyze the feasibility of numerical simulation about wave condition on sheltered waters. At last, SWAN model is used to simulate the wind wave field on water areas which is covered by the submerged breakwater on the extreme condition of 12-class Beaufort scale wind, and satisfactory simulation results are achieved.