Abstract:The Kouanzhi 12.5 meter-deep-water channel regulation project is located in the left branch of the Yangzhong River and the main construction work consists of ripraps.The project area is characterized by long distance offshore,deep water depth,changing flow velocity range,etc.It is difficult to accurately predict the riprap throwing point at the construction site.Thus we carry out a field experiment for riprap throwing distance,and obtain a formula for predicting the throwing distance at the period of the rising and falling tide,which is further used in Manyu-Shoal submerged-dike construction.The results show that the riprap throwing distance is influenced by the tidal current acceleration,which becomes larger during current velocity increasing period while smaller during current velocity decreasing period.Overall,when the current acceleration is smaller than 1.5×10-3m/s2,the throwing distance prediction formula coefficient can be taken as a uniform value of 0.892 for the whole tidal process. When the throwing distance of the group’s median riprap is smaller than 4.5 m,the averaged throwing distance of riprap group can be estimated by proposed formula with a median diameter of the group chosen.The measured dike section profile agrees well with the designed one.This work provides a good method for accurate throwing distance prediction in tidal river.

Abstract:The Fujiangsha waterway in plane presents a pattern of branching twice and coexistence of three branches.With complicated topographical conditions and intense local channel evolution,it is one of the key sections of the 12.5 m deepwater channel of the Yangtze River below Nanjing.In order to demonstrate the effect of Fujiangsha waterway regulation project after its implementation,based on the measured topographic and hydrological data,the evolution of beach and trough,the adjustment of branching ratio,the effect of beach consolidation and the improvement of waterway conditions before and after the implementation of Fujiangsha waterway regulation project in the 12.5 m deepwater channel below Nanjing of the Yangtze River are systematically compared.The results show that the Fujiangsha waterway regulation program is feasible in general,and the regulation effect is achieved as expected.However,attention should be paid to the effect of bottom sediment movement along the Jingjiang River on siltation of the Fubei waterway.

Abstract:The ground-breaking performance of the high-pressure flushing nozzle has a significant influence on the dredging efficiency of the trailing suction dredger.The ground-breaking performance of the high-pressure flushing nozzle is studied based on the experiment test.The results show that with the increase of the target distance,the ground-breaking depth of the high-pressure flushing nozzle gradually decreases and the ground-breaking width gradually increases;with the increase of the nozzle outlet pressure,the ground-breaking depth gradually increases and the ground-breaking width gradually decreases;with the increase of headway,the ground-breaking depth and width gradually decrease.Comparied with the ground-breaking performance of the high-pressure flushing nozzle with and without wear blocks,the overall change trend of the ground-breaking characteristics of the two nozzles is basically the same.When the nozzle is at the same distance from the mud surface,the ground-breaking depth and width of wear block high-pressure flushing are both larger than those without wear block,and the comparison of ground-breaking width is more obvious.

Abstract:Aiming at the problem of the mean overtopping of vertical breakwaters with the bed under irregular waves,the influence of the factors such as the height of the top of the breakwater,wave height,period and foundation bed on the overtopping is studied by means of physical model test.The results show that the height and period of the top of the vertical breakwater are important factors affecting the mean overtopping of the vertical breakwater.The width of the bed has a limited influence on the mean overtopping of vertical breakwaters when the relative width of bed is Bt/Hs=1~4.7.Meanwhile,the mean overtopping of vertical breakwaters with bed increases first and then decreases rapidly with the increase of the influence coefficient h*,and has a maximum value near h*=15,while it remains basically unchanged after h*=30.On the basis of the physical model experiment,the new calculation formulas on the mean overtopping of vertical breakwaters are set out,which may serve as a reference for the engineering design.

Abstract:In order to solve the problem of stone powder reuse in the process of sand production,we study the influence of sandstone powder on mechanical properties of mortar.By means of XRD DSC-TG,SEM and MIP,we analyze the influence of sandstone powder on the morphology and pore structure of hydration products of cement mortar.The results show that the mechanical properties of the mortar increase with the increase of the content of sandstone powder when the content of stone powder does not exceed 11%.With the increase of the content of sandstone powder,the mechanical property of the mortar gradually improves,while the porosity,median pore diameter,maximum aperture and average pore diameter of the mortar reduce.It proves that the stone powder can optimize the distribution of the pore structure of the mortar.The CaCO3 of the sandstone powder can react with C3A,and the reaction product is C3A·CaCO3·11H2O.Particle filling effect and chemical activity of sandstone powder are the main reasons for the improvement of the mechanical property of slurry.The results may serve as reference for the preparation of sand concrete and reuse of stone powder.

Abstract:Based on the analysis of the natural conditions of Quanzhou Bay,this paper studies the impact of Xiutu artificial island on the hydrodynamic and sediment environment before and after its constraction by mathematical model from the aspects of hydrodynamic force,flow pattern,erosion and deposition.The results show that after the completion of the artificial island,the tidal capacity will be reduced by about 2%,which is in line with the flow pattern around the artificial island,but has some impact on the local flow field;some shoal sand sources will be solidified,and the macroscopical scouring and silting effects can be controlled.It can provide reference for the development and protection of similar projects.

Abstract:In view of the problem that there is no systematic guidance for the design and construction of temporary clip structure of piles for pile supported wharf at present,we study the elevation determination for temporary clip structure under strong wave condition based on an actual project case,and apply the physical model test to measure the wave force of the clip structure at different elevation.We determine the elevations for the temporary clip structures of piles at two stages of construction according to the schedule,which are calculated by finite element analysis software.It achieves good effectiveness on site,which can provide references for the similar projects.

Abstract:As a new type of mooring system,automatic mooring system has been widely used abroad,but it has not been applied in China.The paper introduces the advantages and deficiencies of automatic mooring system and analyzes the effect on plane layout of wharf and economy.Through analysis,it can be concluded that the advantages of the system include faster and safer mooring and departure operation of ships,and small amount of motion during mooring.At the same time,the system can reduce the length of the wharf according to the type of the wharf;in the case of reinforcement and transformation,the system can complete the upgrading of the wharf without lengthening the wharf under the condition of only a few modifications to the original wharf.In the case of high unit cost of the wharf,the automatic mooring system can achieve good economy by reducing the length of the wharf.

Abstract:For the high-piled wharf,the damages of components in different positions,degrees and quantities have different effects on the dynamic characteristics of wharves.Adopting the probability sensitivity analysis,we study the changes of dynamic characteristics under conditions of concrete foundation pile damage and superstructure damage.By establishing the finite element model of the high-piled wharf,we analyze the influence of different parameters on the overall dynamic characteristics of the wharf.It is found that the structural dynamic property is sensitive to soil parameters,effective cross-sectional area of piles and elastic modulus of some piles.But,it is not sensitive to the damage of crossbeam and longeron.The change of the first third-order natural frequency of the wharf can be used as an index to reflect the overall damage.For frequencies above the fourth order,the vibration mode is the local mode of the pile itself,and its frequency value is obvious only for some piles.The correlation of the first three natural frequency is strong,while correlation between the frequency above the third order and the first three natural frequency is middle.

Abstract:In order to study the differences of the calculation methods for the wave force of small-size pile provided in the Chinese,British and American specifications,in view of the characteristics of pile foundation structure in port engineering and the wave conditions in actual projects,we carry out sensitivity analysis of various factors affecting the calculation results through different cases.The results show that in Chinese,British and American specifications,the wave forces of the small-size piles are calculated all by the Morison equation,and the variation rules of the calculation results by three specifications are basically the same.The different wave theory,the value of inertia coeffecient CM,the marine growth and the group-piles effect are major reasons of calculation result difference.

Abstract:In order to ensure the safety of the bollard structure,we propose a safety evaluation method for the bollard structure based on standard mooring force inversion,take the mooring force under the fixed mooring height and the mooring angle as the standard,analyze the influence of mooring force on the surface strain of the bollard,apply the surface strain of the bollard as a parameter to characterize the mooring force,and establish the standard mooring force inversion model of the bollard.According to the existing bollard structure,we use the finite element method to analyze the surface strain distribution characteristics of the bollard structure,select the finite-point strain inversion standard mooring force,and compare with the finite element simulation results.The results show that the inversion results have high precision,which can monitor the force characteristics of the bollard under complex mooring conditions.Comparing the standard mooring force with the design cable force can realize the safety evaluation of the bollard structure.

Abstract:Shore ramp is an important part of ro-ro terminal structure,which connects the ro-ro ship with the quay.Aiming at the problem of the shore ramp design method for short springboard ro-ro ship(generally less than 5 m),we analyze relevant provisions in Chinese and foreign specifications,and contrast the berthing results of ro-ro ship with springboard in different lengths combining one project in Africa.The results show that when the design water level variation is less than 1.5 m,fixed shore ramp can be adopted according to the codes,but springboard may break away from the ramp or elevation angle exceeds the allowable value.Before design of shore ramp,it is advisable to judge whether the adjustable vertical height variation at the springboard end is bigger than design water level variation+draft variation between full load and empty load condition.If the former is less than the latter,some multilevel fixed ramps with different top elevations can be adopted to solve the berthing problem when the adjustable ramp is not available.

Abstract:As an important guarantee for the natural gas supply in northern China,Caofeidian LNG receiving station has an average of 8~11 LNG ships arriving in port during the winter peak period,which will become the world’s largest LNG receiving station according to the planned expansion.Due to the strict supervision of the LNG ships’ navigation,the increasing number of ships arriving in port will exert significant pressure on the navigation efficiency.It’s necessary to demonstrate the adaptability and construction scale of the terminal and channel.Based on the multi-agent simulation modeling method,the whole process of LNG ship entering and leaving the Caofeidian Port is simulated numerically.The impact of LNG berths on the navigation efficiency of the channel is also evaluated quantitatively under the special channel conditions.The results show that when the number of LNG berths reaches four,the entry and exit of the ship are restricted obviously.The efficiency of the entry and exit of LNG ships can be effectively improved after optimizing the route.

Abstract:In some countries and regions,due to limited terminal construction conditions such as water depth of channel,and the huge construction cost of the large-scale terminal for the import or export of bulk cargos,we probe into the feasibility of reducing the port construction and operating costs through the transfer of water transfer systems.Based on the design procedure of the coal terminal for the power plant in Bangladesh,we discuss how to select the ship to ship transfer system.By the theoretical calculation and simulation,we choose different ship type combinations and select reasonable transport ship type,and determine the channel parameters according to the tide conditions.The result shows that the ship to ship transfer system can be used to avoid the dredging maintenance cost of large terminal construction and long-distance waterway.The cost of ship to ship transfer operation is relatively small compared to the value of the goods,and it can be used as a feasible option for the terminal construction,and provide a basis for project investment decisions.

Abstract:The sediment exchange between groynes and mainstream and topographic change in the groyne fields under different plane layout schemes of engineering work are important issues of the siltation mechanism and sedimentation reduction measures of the deep water navigational channel in the Yangtze estuary.However,there was not much research related to it in the past.The sediment exchange between the groynes and the mainstream and the topographic change are related to the turbulent structure and the time-averaged flow field,that is,the large-scale coherent structure of the mix layer between groynes and the mainstream interface,and the time-averaged large-scale circulation in the groyne fields.In the case of unsubmerged and submerged groynes,the mass exchange coefficient between the groynes and mainstream has little change,about 0.02.There is no equilibrium profile(Rouse distribution)of suspended sediment in the groyne fields.Both suspended and bottom sediments have net sediment transport to the groyne fields.It needs about 5~6 years to reach the quasi-equilibrium state for sedimentation in the groyne fields,but it was basically completed in the first two years.

Abstract:Wujiang River is an important part of the national planning of “Two Horizontals,One Vertical,Two Networks and Eighteen Branches” high-grade waterways.With 2018—2035 as the implementation year,the top-level design of Wujiang River water transport market development strategy is constructed in order to achieve the important goal of prosperity of Wujiang waterway market after resumption of navigation.The strategic orientation,strategic principle,strategic goals of promoting the development of Wujiang River water transport market after it’s re-navigation are defined.Strategic deployment is carried out step by step.The strategic key tasks of promoting the“three major constructions”,upgrading the“four major levels”and improving the“five major systems”are established.It is proposed to establish a guarantee system including strengthening leadership of industry organizations,establishing a joint coordination mechanism,speeding up the construction of water transport personnel,strengthening the guarantee of water transport funds and increasing policy support.

Abstract:Lingbi ship lock is the key node of the resailing project of New Bianhe River,which has quite large scale and high hydraulic indexes.According to the layout characteristics of the resailing project of New Bianhe River and the ship lock and the demands of the Design Code for Filling and Emptying System of Ship Locks,the type of filling and emptying system of Lingbi ship lock is put forward to be short-culvert concentrated filling and emptying system.The area of the culvert transect at the valve is calculated,and the detailed layout of the filling and empting system and the valve opening modes are designed.Moreover,hydraulic characteristics during lock filling and emptying are calculated by lock filling and emptying mathematical model.The results indicate that the detailed layout of the filling and empting system and the valve opening modes is reasonable,and the hydraulic characteristics can fulfil the design and criteria demands and be able to achieve the desired design objectives.

Abstract:The traditional surveying methods have some disadvantages,such as low accuracy and time-consuming in surveying bridge and other river-crossing structures.Based on the discussion of the principle of 3D laser scanning measurement,this paper applies the method of ground 3D laser scanning to the surveying of river-crossing structures.Taking the survey of an inland river bridge as an example,the coordinate transformation of a single site cloud after registration is carried out to obtain the results of target point cloud,and the point cloud coordinates of several checkpoints are compared with RTK coordinates to verify the accuracy.It is shown that the positional accuracy of ground 3D laser scanning technology is superior to 6 cm,which meets the requirements of urban river-crossing structure modeling.The experience could be used in the application of 3D laser scanning technology in municipal surveying.

Abstract:Taking the fishway project of Jiepai hub as an example,we simulate the downstream channel of Jiepai hub by using ecological hydraulic characteristics and two-dimensional hydrodynamic model,analyze the hydraulic characteristics of fishway entrance under multi-complex scheduling of power station and sluice gate control,and optimize the scheme.The results show that the flow index of fishway entrance under new and old power station operation is rather large and beyond the scope of smooth upward trace of fish for the previous design scheme.While the flow velocity near fishway entrance is apt to satisfy the design requirements if outlet channel of power station near fishway entrance is properly widened.It is suggested to further excavate the left side of the original design tail water outlet so as to make fishway entrance move upward,and create good conditions of fishway entrance.

Abstract:Aiming at the navigation-obstruction problem by sandbar near the Zhaohe River estuary,we adopt both field data analysis and 3-D flow sediment model to investigate the characteristics of sediment transport under wave and current,and discuss the layout of channel regulation scheme. Results show that wave breaking in shallow water will increase sediment concentration at the Chaohu Lake. Under the action of wind-induced lake current,the nearshore sediment is characterized by wave lifting sediment and lake current transporting sediment. Combining with the practical experience of channel regulation,we put forward the idea of integrating channel regulation with dredging. By evaluating various schemes,we know that the dike-building scheme can obviously reduce the siltation amount of the channel,and the bilateral dike-building scheme shows a better effect. The high bilateral dike scheme with gentle slope scheme is recommended through comprehensive analysis.This research will provide technical reference for similar channel regulation near the river estuary into the lake.

Abstract:In view of the problem that the dredging supervision is difficult to cover all ships all day and cannot achieve real-time monitoring,we analyze the high frequency data of AIS(automatic identification system)of a cutter suction dredger,including the dynamic longitude,latitude,speed,heading direction,etc.,and study the identification and prediction of ship construction trajectory by using the DBSCAN(density-based spatial clustering of applications with noise)clustering algorithm to roughly identify the construction area,using the LOF(local outlier factor)algorithm to remove the non-construction trajectory in the trajectory,and using the time series ARIMA model to predict the ship construction trajectory.The results show that DBSCAN clustering algorithm combined with the LOF algorithm is reasonable and feasible,and ARIMA(autoregressive integrated moving average)model is characterized by high accuracy,real-time and easy realization.

Abstract:Aiming at the lack of information transfer among the traditional design processes of inland waterway dredging engineering,we propose the BIM forward design idea of inland waterway dredging engineering through comprehensive analysis of the Civil 3D characteristics and special requirements of design,establish the BIM forward design method of inland waterway dredging engineering based on Civil 3D,and improve some of the functions of dredging engineering quantity output and batch drawing during the design processes through secondary development.The results show the BIM forward design method is applied to the dredging project of Modaomen waterway,which effectively improves the design efficiency.It can provide references for the similar projects.

Abstract:When calculating the compression-buckling stability of pile foundation in waterway engineering,the length coefficient of the compression bar in the current code of our country is based on the ideal constraint,but the actual constraint of pile foundation in most waterway engineering is not consistent with the ideal constraint,and the pile top is assumed to be fixed or hinged to be dangerous.Aiming at the above problems,based on the analysis of the actual confined state and stress state of pile foundation,a new limit equilibrium equation is established,and the compression-buckling stability length coefficients under different confined states and different equivalent pile numbers are obtained.The main recommendations are:for most projects,when the pile tip and the pile top are hinged,μ is recommended to be no less than 1.0;when the pile tip or top is fixed and the other side is hinged,the μ is recommended to be 0.80~1.43;when the pile tip and the pile top are both fixed,the recommended value is 0.60~0.72.The conclusion of this paper can provide a basis for optimum design of pile foundation with large slenderness ratio in waterway engineering,and can also provide a reference for revision of appendix to the code.

Abstract:A port project in Namibia was built on diatomaceous soil more than 20 meters thick,thus the settlement of the foundation caused by backfilling in the rear land area brings serious negative friction problems to the pile foundation of the wharf.Aiming at the problem of negative friction in this project,the relevant clauses of the European Standard Code are studied and the bearing capacity of pile foundation under the influence of negative friction is calculated.The varieties of engineering countermeasures are proposed to reduce the adverse effect of negative friction,such as delaying the construction time of pile foundation,driving steel casing through diatomaceous soil layer,increasing the diameter of pile，increasing penetration depth and enlarging pile base.Among these measurements,delaying the construction time is the lowest comprehensive cost solution.The calculation method adopted in this paper can provide a reference for the negative friction calculation of pile foundation in similar foundation.

Abstract:In order to keep enough bond stress between pile foundation and pile core concrete and avoid increasing construction period and money caused by welding shear key,we study the design method of API(American Petroleum Institute),DNV(Det Norske Veritas),UK DOE(United Kingdom Department for Environment) and Code for Pile Foundation in Port Engineering,and collect the experiment achievements of relevant domestic scholars.Based on the example of Panama wharf project,we carry out the bond stress test of pile core concrete,determine the design parameters by regression method of formula in API code.The shear bond in pile can be cancelled by demonstration.The results show that the shear key is cancelled successfully,which can save 3.5 million yuan and about 2 months construction period.

Abstract:Aiming at the problem that the treatment effect of shallow dredger fill mud layer is relatively poor,we analyze the reinforcement mechanism of combination of wide and narrow drainage plates,and apply the method of indoor and field test to compare the physical and mechanical indexes of wide and narrow hot melt drainage plates and the reinforcement effect of single using different width drainage plates.The results show that the reinforcement effect of wide plate is slightly better than narrow plate.The reinforcement effect of combining wide and narrow plates is better than single wide plate in several aspects,such as the dissipation of pore pressure and the vane test shear strength after reinforcement in drainage filling mud layer.The method is economical,which can provide references for the similar projects.

Abstract:Post-tensioning prestressed long tubular section concrete pile is made by centrifugal technology and single tubular section with the length of 8 m or more,which has outstanding advantages in the field of port engineering pile foundation.In order to study its mechanical bending property,we analyze the bending property of 1400 mm diameter long tubular section pile,carry out the bending property tests of its tubular section and joints,and monitor the deformation and failure during loading.The results show that the bending property of long tubular section pile is closely related to its concrete strength grade,tension control stress and prestress loss.The production technologies of double-layer end die and graded tension make the new tubular pile have superior bending property.It is a cost-effective pile type suitable for coastal engineering and has wide application prospects.

Abstract:Pile foundation platform is widely used in coastal soft soil foundation.We carry out the numerical simulation of an irregular pile foundation platform,firstly establish the three-dimensional finite element model of a large platform project by using ANSYS finite element analysis software,select a suitable contact model to simulate the interaction of pile and soil,and carry out the whole operation of the model after applying the design load.The results show that in the model,the maximum friction stress near the height of the pile height 12.5 m is reached under the pile-soil interaction,and the maximum of the few friction stresses occurs at the height of 10 m or 15 m at the pile height.The frictional stress of piles increases continuously along the direction of horizontal load.

Abstract:When the slope foundation soil is underconsolidated,not only the influence of the negative skin friction of the pile foundation in the slope area,but also the lateral extrusion on the pile foundation due to slope soil should be considered.But no specific provisions for the latter issue are recommended in the current code and manuals.To solve this problem,combining the actual engineering design,we analyze the interaction of the underconsolidated soil foundation slope and pile foundation by using the soft soil model and the Mohr-Coulomb model based on geotechnical engineering finite element simulation software PLAXIS.The result shows that the calculation of slope stability tends to be safe without considering the effect of pile foundation;however the calculation of pile foundation tends to be unsafe without considering the influence of the soil consolidation deformation of the slope.It is suggested that the design of pile foundation should consider the effect of lateral soil pressure on the pile due to the slope deformation,especially when the interaction between the under-consolidated foundation slope and the pile foundation is complex,more attention should be paid to the pile design,for the consolidation settlement of slope soil has obvious influence on pile foundation.

Abstract:In view of the unreasonable standard of the original design of steel pipe piles in the coral reef limestone area of Kenya,we study the law of the new standard of the sinking of steel pipe piles,and obtain the recommended standard of the sinking steel pipe piles in the coral reef limestone area based on the theoretical calculation by Haili formula,the high-strain test,the static load test of anchor pile,and combining with the sinking construction of 1 440 steel pipe piles：1) The final set shall be the main stopping criteria and design pile tip level as minor one in the coral reef limestone area in Kenya;2)12~18,7~10 and 4~8 mm/blow can be the final set respectively for the φ1 200 mm×12 mm、φ1 200 mm×18 mm、φ1 200 mm×24 mm steel pipe piles with 20 t-hammer and 1.2 m drop height.The study result may serve as a reference for the sinking construction of steel pipe piles in the coral reef limestone area in Kenya.

Abstract:The numerous methods of the liquefaction determination are available in the worldwide.Due to the different determination basis of each method,the different calculation accuracy and different conclusions may be achieved by different methods.In order to improve the accuracy of the liquefaction potential determination,we compare and analyze the most commonly used methods for liquefaction determination,and then further clarify the applicability of NCEER method and LPI method for different seismic liquefaction sensitivity requirements.The results show that NCEER method can be used when the sensitivity of seismic liquefaction is high,and it is more suitable for evaluation of single point liquefaction potential.LPI method can be used to evaluate the overall liquefaction potential when the seismic liquefaction sensitivity is low.The results are successfully applied to the ground improvement of the inlet canal in JIGCC project,which can provide strong technical support for the project construction.