Abstract:The segment wavemaker is an important laboratory equipment in the study of properties of wave and the stimulation of real sea wave.Relative width of wavemaker and wave period are significant factors which influence the quality of waves generated by segment wavemakers.The theoretical properties of oblique wave generated by segment wavemakers are studied through numerical model.The influence of wave period and relative width of wavemaker on wave propagation is analyzed,and the variation of effective test area of serpent-type wavemakers is concluded.The results may serve as reference for the practical use.

Abstract:It is the common method to design sloping seawall by calculating the mean overtopping.The research process and relevant calculation formulae of the mean overtopping at home and abroad are summarized.Based on the overall physical model experiment，we analyze the relationship of wave direction and mean overtopping of sloping seawall，and propose the adjusted computational formula of the mean overtopping.

Abstract:For the safety evaluation of rubble-mound breakwater under earthquake,Chinese standard defines only FOS factor in the design concept which will lead to an unfavorable situation in the international competition.This essay introduces the Makdisi & Seed method for the rubble-mound breakwater seismic displacement calculation,to serve as reference for similar projects in high intensity earthquake area.

Abstract:Damrey typhoon is the strongest typhoon landing the norther area of the Yangtze River since the founding of new China.Applying the Jelesnianski typhoon parameter model,MIKE-SW wave model and MIKE-FM hydrodynamic model,we study the waves and storm surge distribution characteristics when the typhoon landed in Jiangsu.Calculation results show that the typhoon parameter model and the wave model verify well,and can provide the accurate dynamic condition for the storm surge simulation.During the typhoon transit,the maximum wind speed is more than 40 ms in Lianyungang sea area and the sea level rise obviously.Near the typhoon center,the biggest storm tide is 1.7～1.8 m and the storm tide is 0.6～0.7 m at the high water level.The simulation system can accurately simulate the storm surge process during the typhoon period in Lianyungang sea area,and it is of significant value in prevention and mitigation of the typhoon disaster.

Abstract:The compression tests were conducted on geotextile bags with sand of different sizes,different volume and different compactness to explore influences of friction,compactness and size on the compressive strength and failure mode.The calculation formula of compressive strength considering the interface friction and compactness was proposed based on the existing theoretical research results.The results indicate that the compressive strength of a single sample is greater than that of many samples,so the existing studies on the single geotextile bag with sand have some deficiencies.The compressive strength of geotextile bag with sand decreases with the increase of the compactness.The sizes have a little effect on the mechanical and deformation and have significant effects on the ultimate bearing capacity.The failure mechanism of geotextile bag with sand is different under different compactness:it quickly produces the tensile deformation and failure when the compactness is large,and failure occurs mainly in the sewing interface which is relatively weak.With the decrease of the compactness,the geotextile bags show progressive failure caused by the strain localization,which is unfavorable because the failure is uneasy to find in the practical engineering.The comparison with the test results indicates that the theoretical calculation method can be used to predict the compressive strength when the tensile failure.

Abstract:Naturally immersion in 3% NaCl solution and fast freeze-thaw were tested for the air-entrained high-performance concrete. Contents of chloride ion in concrete and relative dynamic elastic modulus after different freeze-thaw cycles were investigated.According to the principle of damage mechanics,the relationship between the freeze-thaw damage and chloride diffusion coefficient,freeze-thaw cycles are studied.Test result indicates that the freeze-thaw cycle leads to degradation,and increases the chloride diffusion coefficient of concrete.The diffusion coefficient is 1 time of undamaged concrete when the damage degree is 5%.The relationship between the damage degree of freeze-thaw,chloride diffusion coefficient and freeze-thaw cycles conforms to the exponential relationship.

Abstract:To study the influence of the axial rigidity coefficient on the bending moment of the high-pile wharf,according to the fact that different axial rigidity coefficients are corresponding to different bending moments,we introduce the dimensionless bearing relative coefficient α to research systematically the influence of α on the bending moment under different load distributions.It is concluded that the axial rigidity coefficient mainly influences the bending moments within the range of 0～1.5 side span,the longer the cantilever,the smaller the effect;there is a linear relation between α1/3and α23to the bending moment.By the linear fitting,we find the influences of α on the bending moment under different load distributions,and let the designers and researchers better understand the relationship between the bending moment and axial rigidity coefficient.

Abstract:Key points about ASCE standard Seismic Design of Piers and Wharves（ASCE/COPRI 61-14）are expounded.This standard has the following characteristics:1)The design classifications of the high,moderate and low are prescribed according to the importance of piers or wharves to the regional economy and the necessity of post earthquake recovery;2)The operation level,contingence level and design earthquake are used for the seismic design;3)In addition to the force-based design method,it also provides a displacement-based design method;4)The capacity protection idea is introduced to reduce the damage to the piers or wharves during the earthquake.The advices for developing the seismic design methods of port in China are put forward based on the current domestic and foreign codes.

Abstract:Based on the pile-rigid platform spatial simplified calculation model, and considering coordinate transformation matrix, we develope the space simplified method for general high-pile wharf under lateral loads, which is verified by examples of the upgrading project. The examples show that the lateral displacement and internal force result of the pile top by the 6-D space simplified method are close to the that by the finite element calculation, and the accuracy of the space simplified method can meet the structural design requirements. Based on five kinds of reinforcement programs, we draw the conclusion that the program strengthening at the sea side shall be consider in priority. The results indicate that the advantage is not obvious for the structure with double battered piles. Considering the arrangement and reducing the amount of construction, we recommend the program of vertical and battered piles.

Abstract:The spacing between piles is directly related to the incident wave force on piles and the drag force on the platform or the upper structure.A three-dimensional numerical wave flume was developed based on software FLOW-3D,and an experimental investigation was carried out firstly to confirm the efficiency and accuracy of the numerical simulation,and then the influence of spacing L on the wave force on both upstream and downstream piles was numerically studied.The results indicate that both forces on upstream plies parallel to the wave direction and perpendicular to the wave direction are different from the case of isolated pile because of the interaction of the piles,and the grouping effect coefficient KG is closely related to the spacing L.For grouping effect coefficient parallel to the wave direction,when the two plies are in small spacing,the upstream plie KGxu＜1.0,and the downstream plie KGxd＞1.0,and the grouping effect coefficient KGy perpendicular to the wave direction can reach 3.0～4.0.With the increase in the spacing between the piles,KGxu increases gradually,whereas KGxu and KGy decrease.The interaction of piles can be neglected when the ratio of spacing L to the pile diameter D reaches 4.0.

Abstract:On the basis of the research on the handling technology of the heavy lift terminal of the bridge crane at domestic and abroad,this paper puts forward a heavy lift terminal handling technology based on the double-span bridge crane and cantilever steel structure.The key technology is to adopt the over-crossing double-span heavy bridge crane and light bridge crane and the large crane cantilever steel structure foundation.The technology has been successfully applied to the heavy lift terminal of Yibin port.The successful application brings a great impact on the port transshipment logistics of heavy lifts on the upstream Yangtze River,and further promotes the development of the regional transport and heavy industry.

Abstract:This article researches the sensitive factors，which influence the wave dynamics impacting on the channel development during the flood and dry season,and the influence mechanism in the mouth bars of the Yangtze River estuary.Some perceptions are as follows:1)the wave period and direction are two sensitive factors and their changes play a significant part in the sediment movement;2)for the short-period waves,the impact on the riverbed is mainly in the shallow water,while for the long-period waves,the influence occurs both in the shallow water and the deep water;3)usually,the total wave energy dissipation in the mouth bars caused by on-shore wind and off-shore wind differs in an order of magnitude at least;4)during the dry season,the off-shore wind is primary,and the wave characteristics are short-period,steep,scattered and low-energy;while during the flood season,the on-shore wind is prior,and the waves show long-period,rounded,regular and high-energy.

Abstract:A three-dimensional point-type Doppler velocimeter(ADV)is used to measure the flow field in the spur dike area,and a high-precision force balance and a digital strain data acquisition instrument are used to measure the longitudinal and transverse two-dimensional force conditions of the ship model at different positions in the spur dike area under different flow velocities.On this basis， the force characteristic of the ship navigating in the spur dike area is analyzed， and the navigation safety of the ship near regulating structures is investigated from the force perspective.The experimental results show that when the ship passes by the spur dike， the transverse force will have a forward(thrust)peak and a reverse(suction)peak.The forward(thrust)peak appears at the position where the ship center is moved upstream of the spur dike in the range which is 0.56～0.67 time of the ship length;the reverse(suction)peak appears at the position where the ship center is located downstream of the spur dike in the range which is 0.11～0.44 time of the ship length;the longer the transverse distance between the ship and the dike head is， the later the extreme value will appear.The extreme value of longitudinal force appears at the position where the ship center is located downstream of the spur dike in the range which is 0.065～0.28 time of the ship length;as the approaching flow velocity increases， the extreme point tends to evolve downstream.

Abstract:Valve hydraulics problems are the key technical problems in single-step locks with high head.The lock with two levels of water-saving pools is carried out to solve the problem in Datengxia lock,based on the theory of water-saving shiplock abroad.It is concluded that the water-saving shiplock can reduce the work head with 20.125 meters and the water-saving rate is 48.76%.Comparing with the single-step locks,it can simplify the filling and emptying system because of the lower head.Besides,the water-saving shiplock has a broad application prospect in high dam navigation which considers both power and agricultural irrigation.

Abstract:Yanziwo waterway is one of the key navigation-obstructing shoals in the middle reach of the Yangtze River waterway,which has the plane characteristics of straight braided channel,and navigation-obstructing shoals are easily formed at the branched estuary.When the scattered shoal emerges,the navigation-obstructing problem is the most serious.After the implementation of the Three Gorges project,some adverse adjustments appeared.Already running project had guarded the key section.However,with the increasingly impact of the Three Gorges project,the channel condition of Yanziwo waterway is still instable.This paper analyzes the evolution of the river bed and characteristics of the navigation obstruction before and after the construction of the old project and proposes the regulation ideas and solutions.It also puts forward the engineering structure design,focusing on the refinement and optimization processing of the new and old engineering convergence.The research result may provide experience for similar regulation engineering design of the Yangtze River waterway.

Abstract:For the low-head hydro-junction,we usually adopt the way of stilling basin’s bottom underflow energy-dissipation to reduce the sluice discharge’s flow energy.The location of the baffle pier has a great influence on the form and strength of the hydraulic jump,which affects the dissipation of the stilling basin.Adopting the computational fluid dynamics software Fluent’s VOF model,we investigate the effects of the location of the baffle pier on the stilling basin,inland waters jump’s characteristics,distribution of the turbulent kinetic energy dissipation rate and energy dissipation ratio.The results show that the location of baffle pier will affect the stilling basin energy dissipation.When the baffle pier is arranged at the 0.65 and above length of the baffle basin,there is a tiny difference about the effect of energy dissipation; When the baffle pier is arranged at the 0.35 length of the baffle basin,the energy dissipation ratio of stilling basin is the maximum,with a 5% energy dissipation improvement comparing that when the baffle pier is arranged at the 0.65.

Abstract:Based on the research results and the field data,we analyze the recent evolution regularity and the navigation-obstructing characteristics of the waterway,and predict the trend of evolution.According to the waterway regulation target,we propose the regulation idea and tentative regulation scheme.

Abstract:Based on the measured topographic data for many years,and combining with conditions of water and sediment upstream of the Yalu river，this paper analyzes the cause of large erosion and deposion on the riverbed of highway bridge waters in the period of bridge construction.The results show that from March 2010 to September 2010，the runoff is larger and the riverbed erosion is obvious,which is featured with erosion at the right side of the protruding shore beach and deposition at the left side of the concave bank deep grooves.The main reason for the large erosion during construction of the bridge is the strong erosion at the early stage and automatic re-balance of the riverbed.During the bridge construction,the dense pile groups of the construction trestle and transport facilities promote greatly the backsiltation after the flood in 2010.

Abstract:The waterway regulation engineering is very difficult in middle Yangtze River which is called Jingjiang reach because of the special flow and sediment characteristics.The soft mattress with riprap and steel wire mesh protection structure is used as a typical waterway regulation measure to make the bank shore steady in recent years.Due to the lack of intuitive and practical software combined with the terrain measurement instruments,there are many difficulties in bed form monitor during the underwater riprap construction.This paper develops the real-time monitor system on the underwater riprap bed form based on the multi-beam terrain scanning and 3D-VR technology to compare the underwater terrain before and after the riprapping.The system can feed back the information once the riprap form is beyond the safe threshold value and warn the operator to do some remedial work.The research result will benefit the quality control of the construction of underwater riprap significantly.

Abstract:Manual processing of underwater digital elevation model (DEM) consumes more time and brings efficiency-bottleneck problems.An automatic underwater DEM processing system for the Yangtze River,which is composed of the automatic water depth data monitoring and reading module,automatic DEM processing module,automatic thematic map processing module and process monitoring and displaying module is proposed.The input water depth data could be processed into regular grid DEMs and thematic maps automatically and efficiently by the system.The system can reduce human workload and achieve real-time DEM data processing,and solve the aforementioned efficiency-bottleneck problems.

Abstract:Existing researches on the status of port production operations were concentrated on the channel transit capacity on the basis of the vessel traffic flow.However,the actual port production operation should be regarded as a random service system and various random factors of navigable environment should be considered in term of channel transit capacity,and in view of matching with berths and anchorage.By adopting the multi-agent simulation technology and simulation software platform Anylogic,a simulation model for port production operation system,which is a scientific and objective reflection of the actual port production operation,is employed to analyze the logical structure of the entire entry and departure process for vessels and to provide technical support and decision-making basis for the port layout and waterway construction projects.

Abstract:There are different types of defects of large pipe piles,such as concrete shed and steel corrosion,which have an unfavorable influence on the bearing capacity of the dock.Based on the complete pile-soil load transfer system theory,the formula of the remaining bearing capacity of the defect pile is derived.The influence of defects like concrete spalling and steel corrosion on the ultimate bearing capacity of a single is studied.The result reveals that the position of concrete spalling has an influence on the vertical compress ultimate capacity and the vertical uplift ultimate capacity.When it is inside the soil layer,the vertical compress ultimate capacity will have a decrease of 0.07%,while the vertical uplift ultimate capacity will have a decrease of 1.72%.The axial-compression capacity is different,the impact of the defect on the concrete pile on axial-compression capacity is a decrease of 25.65% and that for the steel cohesion on axial-compression capacity reaches a decrease of 20.95%.The concrete defect on the capacity is much greater.

Abstract:The discontinuous stiffness of large-diameter steel tube and concrete combined pile leads to the complicated stress state at the joint part of the pile foundation and the base rock, the steel casing and the bedrock structure.So, it is needed to put forward a scientific basis to determine the pile foundation’s effective depth of embedment.Establishing the physical model and the numerical model of single pile with large-diameter steel tube and reinforced concrete combined force, we carry out numerical simulation and contrast test of a large number of variable parameters to probe into various factors affecting the lateral bearing capacity of the embedded piles and obtain the mechanical properties of the foundation under the action of the steel tube and the pile foundation.

Abstract:The finite element stress integral transfer coefficient method is proposed to solve the problem on anti-sliding stability of the rock slope with non-penetrating weak structural plane,which can search the position of main anti-slip surface by combining the finite element method with the transfer coefficient method.Based on the stress field analysis of elastic plastic finite element method,we obtain the normal direction and tangential force of each sliding surface using the stress integral.Under the condition of equal safety factor,we simulate the dynamic process of residual thrust transfer along the slip surface to the main anti-slip surface when the slope is unstable,and set up limit equilibrium equations of every slip surface.Finally,we search the starting point position and angle of the main anti-slip surface and the corresponding minimum safety factor using Fortran.The calculation example show that the finite element stress integral transfer coefficient method can accurately find the main anti-slip surface’s position,and the slope stability can be quantified to a specific value.This method overcomes the disadvantages of transfer coefficient method which can only analyze the rigidity and need assume the position of main anti-slip surface.In contrast to the strength reduction method,the error caused by human is also reduced.So the result is more reasonable and reliable.

Abstract:The impact of the clay content,initial relative compactness,consolidation stress,consolidation stress ratio on the dynamic strength of reclamation silty sand in the eastern economic zone of Shantou city is studied by the dynamic triaxial test.The results show that the dynamic strength of reclamation silty sand increases with the silt content.The strength decreases 50% when the silt content increases from 0 to 18%.The dynamic strength does not monotonically increase with the increase of the clay content,and the critical value is 12%.The initial relative compactness has little influence on the dynamic strength.When the consolidation stress is less than 200 kPa,the dynamic strength will increase with the consolidation stress.The dynamic strength increases slowly when the consolidation stress is greater than 200 kPa.When the consolidation stress ratio is less than 2,the dynamic strength increases with the increase of consolidation stress ratio.

Abstract:A collapse accident occurred in large deep foundation pit of X power plant circulating water pump house in V country.To find the reasons,we use the calculation method of “equivalent beam” and“m” to calculate the force state of the supporting structure.The calculation principle of the two methods is described. Based on this project,we carry out the calculation.The results show that the maximum stresses of the supporting piles are more than the allowable stresses of the steels,which is the inevitable reason of the collapse accident.

Abstract:There are essential differences between the composite grounds improved by stone columns and by rigid piles,such as reinforced concrete piles,steel-pipe piles and other rigid piles.The voids of the stone columns can act as vertical drainage channels and accelerate the consolidation of the surrounding soft soil resulting in the improvement of the ground strength.Meanwhile,the improvement effect of the stone column depends directly on the lateral support of the surrounding soil.How to accurately determine the overall shear strength of stone column-soil composite ground is the key task to make full use of stone columns.Taking Hong Kong boundary crossing facilities-reclamation works for example,we compare different calculating methods for the overall shear strength of the composite ground,and carry out some analyses of the parameters using the finite element analysis and in-situ monitoring.This study has significant effect for the calculation of overall shear strength of the composite foundation under similar conditions.

Abstract:Port concrete structures usually need specific protections to improve their durability.In recent years,the silane-based water repellent agents have been used widely for the surface treatment of concrete structures and reliability of this technology has been demonstrated through extensive laboratory tests.However,in the engineering practice,the effectiveness of water repellent treatment may be significantly influenced by the construction performance due to many uncertain restraints on the construction site.Therefore,it is significant to evaluate appropriately the construction performance for the durability and service life design of port concrete structures with water repellent treatment.This paper expounds the results of a detailed investigating program on a newly built port structure,the surface of which was treated with water repellent agents from the concrete cover depth,the silane penetration depth,and the half-cell potential of the internal steel reinforcement.The observation has facilitated important information for the future construction of port concrete structures and laid a solid foundation for the durability and service life design of water repellent concrete structures exposed to marine environments.

Abstract:Based on the nonlinear finite element software ABAQUS,we analyze the current force of mattress in ultra-deepwater and give the simplified formula. Comparing the horizontal force and vertical force at the end of the platform trap door,we obtain the results that the horizontal force can be estimated by the simplified formula and the vertical force can be reckoned by the difference between the gravity and buoyancy of mattress in the engineering application.In addition,it is necessary to adjust the ship ballasts in the process of the geotextiles-laying to balance the hell angle caused by the vertical force.

Abstract:Based on Tianjin waterway project,we study the waterway siltation law during construction,and calculate and recommend the depth reserved for sedimentation during construction,so as to achieve the goal of both satisfying the requirement of channel design and realizing the economicalness of construction.The actual construction effect may serve as a guidance and provide reference for similar projects.

Abstract:Analyzing difficulties of rock dredging engineering by the large trailing suction hopper dredger,and considering the equipment features of the trailing suction hopper dredger,we propose the optimized measure for the dredging engineering of rocks by the large trailing suction hopper dredger from aspects including the construction technology,equipment selection and renovation for adaptability.Based on the practical application and improvement,we get the mature scheme and achieve satisfactory effect.

Abstract:To solve the problem caused by larger-fluctuation river of environmental protection dredging,the paper takes the environmental dredging project of Shanmei reservoir as an example to summarize the way of choosing reasonable dredging time,adopting the proper dredging equipment used for the specific water level,and using the natural drying of solar energy to reduce the water content of the sediment,and thus improve the efficiency and save the cost,to provide experience for the subsequent engineering.