Abstract:An experimental study on wave run-up and reflection on sloping breakwaters through a new type of artificial block TB-CUBE was conducted. It is found that the wave run-up would increase at the beginning and then decrease with the increase of breakwater slope. Additionally，the wave run-up would decrease and then increase with the increase of the water depth. Meanwhile，the reflection coefficient in front of breakwater presented a gradually shrinking trend with the elevated water depth and slope. According to the relevant factors of the wave run-up on the new type of face protection block TB-CUBE，the empirical formula of the wave run-up on the block is fitted，comparison analysis of wave run-up formula is conducted between similar formula from JTS 145—2015 Code of Hydrology for Harbour and Waterway and that from this research. For this TB-CUBE，the combined empirical formula from this study performed better than that in the specification.

Abstract:With the increasing demand for floating breakwaters in coastal engineering and offshore operations in recent years，we propose a new type of floating breakwater with wing plates. Based on the three-dimensional potential flow theory，we calculate and analyze the wave suppression performance of the new floating breakwater，and compared it with the common box-type floating breakwater. It is proven that the new floating breakwater has better wave suppression performance for waves of longer periods. The influence of the cross-sectional parameters of the wing plate floating breakwater on the suppression performance shows that：1）The larger the box width and the deeper the draft，the better the wave suppression performance of the new breakwater. Besides，the longer the wing plate and the smaller the angle，the longer the wave period of best wave suppression performance. 2）Appropriate adjustment of the section parameters can make the floating breakwater with wing plates adapt to more wave environments and add more applicable scenarios.

Abstract:Regarding the problem of corrosion protection of transportation infrastructure such as wharfs and bridges，a large amount of data is collected and sorted，and the basic situation and cost investment of corrosion protection of domestic and foreign wharfs，highways and bridges and other transportation infrastructures are analyzed and explained.The research results show that the corrosion cost of transportation infrastructure is huge，through the adoption of advanced corrosion protection technology and improvement of the awareness of active corrosion protection，the corrosion cost can be significantly reduced. The research results have positive significance for the macro analysis，overall planning，project scheme design and implementation of corrosion protection of transportation infrastructure.

Abstract:The geometric dimension of steel fiber is a key factor for the reinforcement and toughening of ultra high performance concrete（UHPC）. In this paper，the working and mechanical properties of UHPC with different length diameter ratio are experimentally studied，and the influence mechanism of steel fiber length diameter ratio on UHPC is analyzed. The results show that with the increase of the length diameter ratio of steel fiber，the slump and expansion of UHPC continue to decrease and the gas content increases. With the increase of steel fiber aspect ratio，the compressive strength，flexural strength，flexural toughness coefficient and impact resistance of UHPC are increasing，but the increasing range shows a decreasing trend. The length diameter ratio of steel fiber should be controlled at 60～100，and UHPC with excellent construction and mechanical properties can be prepared. The developed UHPC has been applied in the repair and reinforcement of pile foundation of a wharf project and achieved good application results.

Abstract:In view of the characteristics of the wind and wave in the Majishan sea area，this study presents a mathematical statistical correlation analysis with the wind and wave data of a whole year and obtains the distribution characteristics of the wind and wave parameters of the Majishan sea area. The results show that the wave type of the Majishan sea area is a mixed wave dominated by the wind wave. During the observation period，the maximum wave height is 4.59 m，and the average wave height is between 0.20 m and 0.42 m. The maximum wave period is 9.50 s，and the average one is between 2.66 s and 3.01 s. The annual normal wind direction of the Majishan sea area is north-northwest（NNW）. Specifically，the normal wind directions in spring and summer are respectively south（S）and south-southwest（SSW），while those in autumn and winter are both NNW. The annual strong wind direction of the Majishan sea area is also NNW. The correlation between wave height and wind speed in spring and summer is small，while the linear relationship between the two in autumn and winter is significant.

Abstract:Automation and intelligence are the main development directions of terminals，especially container terminals，which are the frontiers of the development of automation. The terminal layout should match the new processes of the automatic container loading and unloading solutions，and a suitable automatic solution should be selected according to the characteristics of each terminal project. This study analyzes the layout characteristics of two typical automatic container terminals and proposes two innovative solutions to summarize their layout characteristics. The results reveal that both innovative solutions can solve parts of the problems in existing typical solutions.

Abstract:This paper uses the three-stage DEA method to eliminate the influence of environmental variables and random factors，measures the efficiency of 20 major ports on the Yangtze River trunk line in 2010，2013，2016 and 2020，and clarifies the temporal and spatial evolution characteristics of each port efficiency. The results show that：1）The environmental variables and random factors have a significant impact on port efficiency.2）The efficiency of the main ports of the Yangtze River trunk line is quite different. The downstream ports are generally more efficient，while the middle and upstream ports are less efficient. 3）Low scale efficiency is the main factor that leads to the failure of comprehensive efficiency to achieve DEA effectiveness. Most of the ports have insufficient investment in resources，fixed assets and capital or have unreasonable structures，and have not been able to effectively exert their scale effects. 4）Some ports have low technical efficiency，and management efficiency and information level need to be accelerated. It is necessary to optimize the resource allocation and improve the port efficiency according to the actual development of each port.

Abstract:To quantitatively analyze the relationship between ports and cities in the Yangtze River Delta and its changing laws，this study takes cargo throughput and urban GDP as measurement indicators and investigates the relationship with the dynamic relative concentration index. The results reveal that 1）the port-city relationships of the 14 port cities in the Yangtze River Delta can be divided into port-driven，port-city coordinated，and city-driven ones，and the changing trends can be categorized as rising，falling，and fluctuating. 2）The development of ports in the Yangtze River Delta is relatively mature in general. In the past 15 years，the port-city relationship has changed from port-driven development to port-city coordinated development，and urban development is relatively more active. 3）The port activity of Lianyungang continues to decline. External factors such as the deep-water channel of the Yangtze River and inland water shipping have brought new development opportunities to ports such as Zhenjiang，Taizhou，and Jiaxing. In the port-city relationships driven by cities such as Shanghai and Nanjing，the active factors of the ports are reduced，and the urban growth effect is far greater than that of the ports.

Abstract:In the design of port engineering，the calculation of wind force on the ship controls the selection of mooring facilities. The calculated value of wind force on the ship is determined by calculation constant，windage area of the ship above water，velocity of the wind，reduction coefficient of nonuniform wind pressure and correction coefficient of wind pressure height change. To avoid the error of parameter value in port engineering design，we study the theoretical calculation formula of wind force in the code. Through the analysis of five parameters in the formula one by one and combined with design experience，we obtain the precautions for the selection of windage area of ship，deduce the selection standard of reduction coefficient of nonuniform wind pressure and correction coefficient of wind pressure height change，and put forward the estimation formula of the representative ship height above water，so as to provide some references for the revision of relevant parameters in the code and engineering design.

Abstract:Spatial reticulated shell structure is commonly used in large coal shed in port engineering. Due to its obvious spatial characteristics，conventional design methods cannot meet the requirements of calculation and analysis. In view of the analysis and design of spatial reticulated shell structure，combined with the coal shed project of the “transform bulk into container transportation” technology and environmental protection improvement project in the west area of Shijiu harbor district of Rizhao Port，the analysis principle，structure type selection，structural modeling，actions on structures and action combination，and post-processing of the results are analyzed by the general structural finite element analysis method. The results show that the spatial structure with the square pyramid double-layer cylindrical shell，the bolted spherical node and the lower chord support can meet the requirements of engineering. The results can provide references for the similar engineering.

Abstract:Gravity quay is a type of quay structure that is widely distributed and used in our country. It relies on the gravity of the structure itself and the filler on it to maintain its anti-slip stability and anti-overturning stability. For the gravity-type quay in the strong earthquake area，in addition to the general static effect during construction and use，it must also withstand the inertial force，active earth pressure，hydrodynamic pressure，etc. generated by the seismic. Especially，when the water level is high，the backfill behind the gravity quay wall is in a saturated state，and strong seismic action will generate excess pore water pressure. Therefore，the seismic design of the gravity quay is very important. This paper compares the seismic effects of gravity wharves in major domestic and foreign codes. For a gravity quay in a proposed port area in North Africa，my country’s Seismic Design Code for Water Transportation Engineering and PIANC’s Seismic design Guidelines for Port Structures are used to compare and analyze the stability of the quay at high water levels under earthquake conditions.

Abstract:The mooring force of ships is an important condition for wharf structure design and mooring bollards selection. The wind，current and wave are the main controlling factors of ship mooring force. Regarding the differences in the calculation methods of ship mooring force in Chinese and foreign wharf structure design standard，the Chinese and foreign codes commonly used in the design of wharf structures（China JTS，Spanish ROM，OCIMF guideline，British BS 6349）are selected to compare and analyze the calculation formulas of wind loads on ships，and the wind loads under different wind direction angles are calculated combined with engineering examples. The result shows that：1）There are obvious differences among different standards in the adaptability range of ships，the selection of wind speed，the area of ships subjected to wind and the wind correction coefficient. 2）The wind load of the 300，000 t tanker calculated by ROM is the largest，and the calculation result of JTS is the smallest.

Abstract:The security of the upright shore-to-ship power supply system will be significantly affected when its cable is pulled up by extra load. To solve this problem，combined with the actual engineering needs of shore-to-ship power supply system under the large water level difference of the Jiuzhou River anchorage in the Three Gorges reservoir area，a connection box lifting device is designed which consists of electric box platform and lifting mechanism. The electric box platform can run up and down the track，and its main structure is truss structure.The lifting mechanism consists of hoisting gear and pulley block which is used to drive the electric box platform. And then，the truss structure is modeled and analyzed using the 3D BIM software Inventor，and the traction of hoisting gear is calculated. The results show that the truss structure can meet to requirements of the strength，the traction can meet the requirements of the hoisting.

Abstract:Valve cavitation is the most important technical issue in the design of a high head ship lock. Domestic and foreign ship lock research and operation experience indicate that under the same buried depth of the valve，the shape of the corridor in the valve section is the main factor affecting the cavitation characteristics of the valve section，resulting in an urgent need to examine the unsteady flow characteristics under different corridor shapes. By investigating an actual project，this paper compares “the corridor shape of top and bottom expansion + the reversed tainter valve” and “the corridor shape of flat bottom and gradual top expansion + the reversed tainter valve” by a model test. A comprehensive comparison of various indicators，such as the hydro-dynamic load characteristics of the corridor in the valve section and the valve opening and closing force characteristics，shows that the former is more suitable for high head ship locks. Nevertheless，this corridor type has its own limitations，such as large engineering amount，complex shape，high construction requirements，and difficult maintenance. In view of various factors，the Qianwei ship lock adopts “the corridor shape of flat bottom and gradual top expansion + the reversed tainter valve” scheme.

Abstract:In the underwater riprap project，block stones with different particle sizes are often used to form block stones for throwing. In the process of underwater throwing of block stones with multiple particle sizes，the block stones will drift due to the interaction between water flow and the block stones，so it is difficult to accurately locate the falling point of the block stones.On the above problems，this paper uses the finite volume method and the discrete element method based on Hertz-Mindlin contact to study the CFD-DEM coupling of the drift process of the multi particle size block stone group after throwing，and obtains the horizontal displacement，settlement time，diffusion process and impact point distribution of the multi particle size block stone group under different incoming flow conditions. The results show that in the same flow field，because the drag force component of the flow field is relatively small，the drift distance and settlement time of coarse-grained block stones are less than those of fine-grained block stones. The block stone groups with different particle sizes are irregularly distributed at the bottom of the riverbed after throwing，and the drift distance generally increases with the increase of velocity.

Abstract:Frequent human activities on navigable rivers and the construction of dams have damaged the river ecology to varying degrees，and the river ecology is under enormous pressure. Based on 34 global golden waterways in the world，global dam data and ecological index data，the impact of dam on river ecology and the role of navigation locks in reducing ecological pressure are studied by regression analysis and factor analysis. The results show that the construction of dams significantly increases the ecological pressure of the river，while the navigation locks can reduce the increase of the ecological pressure of the river and improve the ecology. Ecological pressures of the different exploitation rate waterway with or without locks are not consistent，the waterway with high dam density is more likely to highlight the regulating effect of navigation lock on river ecology. The research results can provide theoretical support for the planning and construction of river shipping under the goal of ecological environmental protection.

Abstract:The Fujiang Bridge of Chengdu-Dazhou-Wanzhou High-Speed Railway is in the complex bridge-group reach. The left bank of the bridge is adjacent to a large wetland park，which intrudes into the navigable hole of 80 m on the left bank of the bridge for the new Dazhou-Chengdu Railway and occupies part of the navigable net width. This worsens the flow conditions in the bridge area，and the bridge area cannot meet the Class V channel standard. This study analyzes the regulation effects of four different dredging schemes by using two-dimensional mathematical flow models and ship maneuvering simulation tests. The results indicate that when Scheme 4 is employed for the large-range dredging of the wetland park on the left bank，and the old Dazhou-Chengdu Railway in the upstream is demolished，the maximum flow velocity in the bridge area is reduced by 0.46 m/s，a reduction of 21.88%，and the maximum lateral flow velocity is reduced by 0.33-0.65 m/s，a reduction of 33.67%. The optimal dredging scheme can effectively improve the navigable flow conditions of the channel in the bridge area and thus ensure navigation safety.

Abstract:Promoting the construction of ecological inland waterways is conducive to a more balanced relationship between ecological protection and inland waterway engineering. Carrying out the project of ecological inland waterways in the new era is an inevitable choice for the water transportation industry to implement the concept of ecological priority and green development and to seek sustainable development of waterway engineering. On the basis of analyzing a large number of research materials，starting from the theoretical framework of ecological inland waterway construction，this paper systematically summarizes the relevant concepts，technologies，and development frontiers of ecological inland waterway construction at home and abroad. Furthermore，the paper also summarizes the achievements and shortcomings of ecological inland waterway construction in China. At the end of the paper，considering the status quo of domestic ecological inland waterway construction，it is proposed that the next step should focus on the research on ecological waterway structure and evaluation methods，ecological restoration，and ecological waterway impact and effect monitoring.

Abstract:The Three Gorges ship lift，characterized by large scale，high technical difficulty，various types of mechanical and electrical equipment，difficult maintainance，and high safety protection level of the operating system，is prone to shutdown failures. As a result，ensuring normal navigation operation became a challenge for this ship lift after its completion. This paper comprehensively reviews the challenges the Three Gorges ship lift has been faced with in navigation conditions，operation and maintenance of equipment and facilities，and ship traffic organization since its trial navigation in September 2016. Then，it systematically outlines the main experience obtained in the operation and reconstruction of equipment and facilities，real ship tests，and supporting facility construction. Moreover，the defects in the navigation operation of the Three Gorges ship lift are pointed out，and future work is suggested.

Abstract:Due to its high gravity and weak torsional resistance，the miter gate will produce torsional deformation when hanging naturally. As a steel member，the miter gate is in an open-air environment，and its temperature is much higher than the ambient temperature under the direct action of solar radiation in summer，which will aggravate the structural deformation of the miter gate. To quantify the influence of solar radiation on the structure of the miter gate，based on ASHRAE clear sky model，the temperature field，deformation and stress distribution of the miter gate are simulated by ANSYS finite element software. The results show that：1）Under the action of solar radiation，the temperature field with uniform spatial distribution is formed，and the maximum temperature reaches 67 ℃ at about 3 pm. 2）The deformation and stress of the main components of the gate still meet the standard requirements under the maximum temperature load. The deformation of the gate gradually increases with the temperature rise，and the displacement of the miter column and the deformation of the back tie rod increase by 1～3 times，which should be paid attention to in practical engineering design.

Abstract:The Qingshan Junction of the Lishui River confronts some flow problems in the upstream entrance area，such as meandering rivers，the topography of bifurcated channels，sudden expansion and reduction of flow sections，and flow rates. This study uses the fixed-bed physical model to study the improvement in flow conditions in the upstream entrance area and the influencing factors and proposes optimization measures to improve flow conditions. The results reveal that the navigable flow conditions cannot be satisfied under the design scheme and Scheme 1 for the improvement to the upstream entrance area. According to the arrangement of Scheme 2，when three current diversion piers are arranged in the upstream entrance area in a non-staggered manner，and the right bifurcated diversion is dredged up to 43.0 m，the flow conditions of the upstream entrance area can be better improved，and the flow conditions in the entrance area of the ship lock under the design navigable water level can meet the requirements of safe navigation of ships.

Abstract:The Doulizi Beach is a low-water and rapid shoal in the upper reaches of the Yangtze River. After the damming and dredging measures are taken，the waterway conditions are improved. This study uses the measured data to analyze the changes in water-sediment conditions，patterns of floodplains and main channels，and waterway conditions in recent years. It proposes a regulation scheme considering the implementation and effect of waterway maintenance and dredging since 2019. The results reveal that under the influence of clear water discharge after Xiangjiaba impoundment and artificial sand mining activities，the scouring and retreat of the left marginal bank is the main reason for the continuous siltation and widening of the moraine wing and tail section of the Miaojiaoqi moraine and difficult waterway maintenance. Under the current river regime and water-sediment conditions，the left marginal bank does not have the conditions for natural recovery，and the siltation and navigation obstruction of the Miaojiaoqi Beach in the dry season will become the norm. The maintenance mode of early dredging after the flood season and the regulation scheme of adding new regulation buildings can reduce the safety risks in dredging construction and normal navigation.

Abstract:Considering that the internal force and displacement of the monolithic lock chamber structure are greatly affected by the height of the lock chamber，this study investigates the internal force and displacement of the monolithic lock chamber structure with a large height-width ratio by the finite-element analysis method. The conclusions drawn are as follows：1）When the height-width ratio exceeds a certain value，the positive bending moment at the root of the side pier of the bottom plate of the monolithic lock chamber is larger than the negative bending moment in the middle of the bottom plate span，and the thickness of the bottom plate is determined by the positive bending moment. 2）When the height-width ratio is less than that value，the trend is just the opposite. 3）For a lock chamber structure with a large height-width ratio，setting a heel plate or an unloading plate behind the lock wall can reduce the positive bending moment at the root of the side pier of the bottom plate，increase the negative bending moment in the middle of the span，and ultimately reduce the displacement of the lock wall. In this way，a more uniform force on the bottom plate allows the thickness of the bottom plate to be reduced to optimize the design and save the cost.

Abstract:Since the 20th century，the frequent sand mining activities in the upper Yangtze River have caused dramatic changes in the river topography，and the sediment deposition in the channel of the sand mining reaches has threatened navigation safety. Taking Lianshitan in the upper Yangtze River as an example，this study comprehensively analyzes its water and sediment conditions and focuses on the changes in river topography and channel conditions after the destruction of the islands and bars. Then，it puts forward a regulation scheme according to the navigation-obstructing characteristics and the external investigation. In addition to dredging and reef clearing to ensure the channel depth，damming and shoal consolidation with backfilling are combined to restore the high and complete form of the Guandaoqi central bar and thereby improve the flow-converging capacity for medium floods. Moreover，the reef clearing stone and ecological fish nest bricks are used to build an ecological conservation area and ultimately create a pleasant ecological environment. The model study shows that the proposed ecological regulation scheme is effective and provides a reference for the regulation of similar shoals.

Abstract:The Three Gorges new channel and the Gezhouba shipping capacity expansion project are fundamental ways of solving the problem of ship congestion at the Three Gorges-Gezhouba hydrojunction. This study develops a prediction model based on neural network to simulate and calculate the freight throughput of the Gezhouba ship lock during the construction from the aspects of implementing cargo transfer over the dam and optimizing ship lock facilities and reservoir scheduling. Then，it explores a feasible navigation guarantee scheme for alleviating the pressure of ships passing through the lock during the construction. The example calculation results show that implementing transfer over the dam reduces the need of ships to pass through the lock by about 5.2% and that optimizing the berthing facilities upstream the Gezhouba No. 1 lock and the discharge of the Three Gorges Reservoir area in dry and flood seasons increases the freight throughput capacity of the Three Gorges-Gezhouba hydrojunction by about 5%.

Abstract:Considering the problems of single maintenance analysis means，lack of quantitative analysis，and insufficient systematic evaluation of waterway regulation buildings，this study proposes a maintenance analysis method for waterway regulation buildings based on building information modeling（BIM）and the geographic information system（GIS）to quantitatively analyze and evaluate the damage to regulation buildings. The research results are applied to the maintenance and management of Jiepai waterway regulation buildings，which verifies the feasibility of BIM and GIS technologies in the maintenance and management of regulation buildings. Moreover，the method achieves the functions of three-dimensional display，building damage analysis，waterway evolution analysis，and analysis of regulation building conditions and solves the problems of single maintenance analysis means and insufficient systematic evaluation of regulation buildings. The proposed method provides an effective means for the maintenance and management of waterway regulation buildings.

Abstract:Regarding the problem of sand blocking in the entrance channel of a tributary of Chaohu Lake，the research of BIM technology application in the calculation and maintenance analysis of the erosion and sedimentation of the entrance channel is carried out. On the basis of summarizing the application ideas and processes of BIM technology in the maintenance analysis of the entrance channel，the Civil 3D surface analysis technology is used according to the measured hydrological terrain data，and the quantitative analysis of the erosion and sedimentation changes in the entrance area of the channel is carried out. The parametric channel model is created by the subassembly composer，meanwhile the channel scale is analyzed in combination with the water level conditions to propose maintenance measures. The results show that BIM technology can accurately and efficiently complete the maintenance analysis of the waterway at the entrance，which can provide references for the deepening application of BIM for waterway maintenance in future.

Abstract:The three Gorges Reservoir runs at the water level of 145-175 m all year round，and the bank slopes in the reservoir area are periodically submerged and exposed. The fall of the water level in reservoir causes the seepage of the soil bank slope，and the sediment is easier to start and aggravate the erosion of the reservoir bank. The bank slope is unstable in serious places. Taking the soil bank slope in the Three Gorges Reservoir area as the research object，aiming at the characteristics of the new ecological slope protection structure—terra block mat slope protection，the indoor generalized model test is used to study the protective performance of the terra block mat under the action of seepage. The soil—retaining and anti-scour performance of terra block mat is analysed through water scouring test under seepage action. The test results show that the terra block mat has good soil retention and anti-erosion performance；water flow erosion intensity is reduced by an average of 83.15% under the condition of no seepage，and is reduced by an average of 88.15% under the action of seepage.

Abstract:Steel pipe piles are the most widely used type of piles in marine engineering. Nevertheless，steel pipe pile driving under complex stratum conditions is often difficult. By investigating an actual project，this paper presents an experimental study of the construction of steel pipe pile driving in a dense sand-bearing gravel and cobble stratum through the stratum in-situ test，pile driving model test，drivability analysis of the foundation pile，and full-scale field test. The results support the following conclusions：1）The experimental results of pile skin-soil friction resistance need proper improvement due to the use of the artificial simulated stratum for model test. 2）For a dense sand-bearing gravel and cobble stratum，a range of 0.7-1.0 is available for the blocking coefficient of the steel pipe pile tip，225 kPa is advisable for the unit friction resistance on the pile skin，and the unit resistance at the pile tip should not be less than 13 MPa. 3）Vibration and impact methods have trouble driving steel pipe piles in a dense sand-bearing gravel and cobble stratum. Consequently，achieving the designed penetration depth might require that part of the soil plugs inside the pile be removed by an appropriate method.

Abstract:In view of the safety and stability problems caused by the foundation trench excavation of gravity wharves to the adjacent engineering facilities，this paper takes a wharf project in western Guangdong as an example and selects the grouting micro-steel-pipe pile as the supporting structure through comparison and analysis of various supporting schemes. The results of theoretical calculation and field practice indicate that it is feasible to adopt multi-row grouting micro-steel-pipe piles as the supporting structure. The whole structure is formed through the “coupling effect” of pressure grouting，and the strength of implanted steel pipes is used to provide resistance，which can satisfactorily eliminate the influence of foundation trench excavation on the adjacent built revetment.

Abstract:Regarding the problem of seasonal and shallow sliding when the slope of the navigation channel is swelling soil，which affects the shipping capacity and engineering safety，we carry out the straight shear test of swelling soil after reciprocal wet and dry cycles and the stability analysis considering the effect of wet and dry cycles based on the treatment project for the destabilized slope of Nanjing section of the Wu-Shen Navigation Channel. The results show that the cohesion and internal friction angle of swelling soil decay gradually with the increase of the number of wet and dry cycles，and the decay mainly occurs in the first three dry and wet cycles，and then gradually stabilizes. The decay degree of cohesion is much larger than that of internal friction angle. Considering the soil strength decay caused by the wet and dry cycle effect is the correct calculation method to obtain the true stability coefficient of swelling soil slopes. The treatment measure of using gate-shaped anti-slip piles is proposed for the unstable slope，and has good application effect and engineering reference significance.

Abstract:Regarding the increasing scarcity of materials such as sand and gravel for the surface filling of soft soil sites，this study conducts laboratory tests on the solidification of soft dredger fill. The research uses unconfined compressive strength tests to compare the reinforcement effects of three curing agents under the condition of a low incorporation ratio. The results demonstrate that the strength of soft dredger fill increases significantly after solidification under the condition of a low incorporation ratio of three curing agents. The addition of compound activator and slag powder to cement can improve the strength of solidified soil，and the effect of slag powder is superior to that of compound activator. The replacement of part of cement with slag powder can further improve the reinforcement effect when the total incorporation ratio remains unchanged. Through the above laboratory tests for the solidification laws of soft dredger fill under a low incorporation ratio and feedback to the engineering applications，this study solves the problem of the scarcity of filling materials in the soft soil sites.

Abstract:Due to construction difficulties，such as ship positioning，anchoring and anchor removal，destruction of blasting line，and verticality control of drilling rig casing，in the construction of rapids shoals in class J sections，the traditional construction scheme is no longer applicable for construction operation. This study summarizes and develops a set of key technologies for borehole blasting construction of rapids shoals with the drilling rig ship through practice. The comprehensive utilization of the modular combination hull，ship positioning system with seven anchor cables，vertical casing guidance system，parallel double-drum windlass，initiation network，and other key reef blasting construction technologies enables the construction ship to be dispatched for construction in any navigation area. In the class IV channel regulation and construction project on Lancang River from Boundary Marker 244 to Lincang Port，the navigation area has many types of dangerous shoals，and the flow velocity on the shoals in this area is 3.5 m/s to 6.5 m/s. The proposed scheme achieves a favorable construction effect. This scheme can effectively avoid such disadvantages as high unit explosive consumption and difficult control of exposed blasting technology under vortex flow，deep rapids，and other complex conditions，and it can thus serve as a feasible and effective construction scheme for rapids shoal construction.

Abstract:By investigating the regulation of the Xigua-Mengsong shoal group in the Level IV waterway construction project on Lancang River，this paper discusses the problem that the construction over-excavation in shoal group reaches can cause an adverse effect on the regulation effect and produce new navigation-obstructing areas. It then combines field measurement data and a physical model to explore the navigation-obstructing characteristics of shoals and the water surface，flow velocity，and parameters of rapids abating before and after regulation. The results indicate that regarding the construction in complex reaches with dense shoals，over-excavation leads to a shoal regulation effect falling short of the design expectations and even creates new navigation-obstructing areas. Appropriate remedial measures，such as backwater and flow diversion，can achieve the expected regulation effect. Future construction at similar shoals should strictly control over-excavation to ensure the regulation effect.

Abstract:Three-cable position system is one of crucial position equipments effecting capacity and safety for cutter suction dredger. Aiming at design of three-cable positioning system，this paper introduces the main components，working principle and design process，forms the calculation process of the external loads borne by the three cable system under different working conditions，analyzes the variation law of the cable tension and the stress characteristics of the cylinder structure by using the methods of frequency domain analysis and finite element analysis，and proposes cable type selection and local structural design method. The results show that under various working conditions，the cable tension increases with the increase of wind speed，and under the same wind and wave conditions，the cable tensions under dredging operation conditions and wind shelter conditions are different quitely，which should be comprehensively considered. In addition，in the design process of three-cable positioning system，special consideration and key strengthening should be given to the parts with large stress.

Abstract:The current specifications of blast compaction are mostly applicable to small-section blasting at the end，the application scope and construction parameters can not meet the requirements of large section embankment，high efficiency and short construction period.To solve the problems，this paper researches on the full lateral blast compaction rapid embankment construction technology.By direct filling to form temporary revetment and full lateral blast filling rapid embankment construction technology，the scope of the specification can be expanded. By optimizing the construction parameters through field tests，the limits of minimum single consumption and embedment depth of blasting compaction are proposed to break through the specification requirements.The results show that the method is suitable for the embankment with the width of section larger than 30 m and the depth of the underlying silt layer is 5-18 m，the best effect is achieved for the treatment of the silt thickness of 10-15 m，the charge required for unit volume of blast compaction can be as low as 0.23 kg/m3，and the elevation of the charge embedding can reach the position 1/3 of the thickness from the silt bottom.

Abstract:This paper is to detect the effect of the water cutoff curtain with high-pressure jet grouting piles. Taking the water cutoff curtain with high-pressure jet grouting piles in a project as an example，this study explores the difference in the construction methods of high-pressure jet grouting piles in China and Russia and the detection method of the permeability coefficient of the water cutoff curtain. The “new double-pipe method” is proposed for construction under specific environment and complex conditions. The permeability coefficient K of the high-pressure jet grouting wall is detected by the method of drilling and coring. The construction method and detection calculation formula have the characteristics of strong operability and reliability. The new detection method for the water cutoff effect of jet grouting piles can reflect the overall quality of the high-pressure jet grouting wall，effectively check the permeability coefficient of the high-pressure jet grouting wall，and comprehensively evaluate the effect of the water cutoff curtain.