Abstract:To ensure the stability of the bank slopes of the Pinglu Canal under the influence of long-term immersion and heavy rainfall and other multiple factors,the changes in the stability safety factor of typical slopes on both sides of the canal under the influence of different channel water level and underground water level are analyzed.The results show that as the water level in the canal rises,the stability safety factor of the slope gradually increases,and for slopes with poor geological conditions,the influence of the water level change in the canal is more obvious.When the water level in the canal rises from the normal storage level to the design flood level,with a rise of 7.17 m,the safety factor increases by up to 0.19.As the groundwater level in the slope body rises,the stability safety factor of the slope gradually decreases,approximately in a linear manner.For every 2 m increase in the groundwater level,the safety factor decreases by about 0.03.It is proposed that in channel engineering,for slopes with poor rock properties and small safety factors,engineering measures such as setting up drainage pipes deep into the slope body,setting up water interception ditches and rapid channels on the slope surface should be adopted to enhance the drainage capacity of the slope and reduce the probability of slope instability during heavy rainfall.

Abstract:The Pinglu Canal is a cross water system connection project,and the water guarantee rate for navigation in the dry season basin is insufficient.The ship lock needs to adopt water-saving technology.Taking into account factors such as water delivery efficiency,water-saving rate,and ship lock capacity,a comprehensive technical and economic comparison is made for the selection of water saving methods and the layout of water-saving pools.It is recommended to adopt a water saving pool scheme with overlapping first and third level water saving pools and dispersed second level water saving pools,with a water saving rate of 60%.The main function of the Madao Hub is shipping,while also taking into account the emergency flood control of the Yujiang River.The dam site is located in a low mountain and hilly terrain,and a double-lane 34 m × 300 m ship lock will be built at once.The ship lock adopts a multi-level water-saving pool scheme.The layout plan is influenced by many factors.By combining the scale of the sluice gate,the layout of the water conveyance system,and the layout of the water-saving pool,the axial spacing between the ship lock and the sluice gate can be optimized to save land resources and engineering investment.Through model experiments,it has been verified that under the conditions of adopting a 4.5 minutes staggered operation of the double line ship lock and optimizing the layout of the upstream and downstream navigation guide walls,the navigation flow conditions in the navigation channel meet the regulatory requirements.

Abstract:The open type breakwater with double baffles has good wave attenuation effect,and has the characteristics of water permeability and environmental protection,which can meet the requirements of the functions of structures due to the marine environmental protection.A study on wave loads acting on a opentype breakwater with double baffles under wave action is conducted to address the current shortcomings in hydrodynamic characteristic research of such structures.A numerical flume is built on the basis of the Fluent model,and the interaction between waves and the breakwater with double baffles is simulated.Then the influence of relative water depth,depth of baffle into water,width on wave load under different wave surface condition between two baffles is analyzed under different water surface conditions between baffles.The results show that when there is no free water surface between the two baffles,the structural load is less affected by the relative water depth and width of breakwater,and increases with the increase of depth into water.For the free wave surface condition,the water movement between the baffles significantly affects the wave load of the structure,the maximum load of the structure will increase significantly,and the relationship between the structural load and the influencing factors will also change.The condition of the free water surface between the two baffles is a common operational state for breakwaters,and it should be given full consideration during the structural design process.

Abstract:The collapse of a landslide dam can pose a significant threat to downstream areas,and it is necessary to thoroughly study the overtopping and collapse processes.The Baige landslide dam on the Jinsha River in 2018 is taken as a reference for experimental gradation.Improvements are made to address the limitations of the landslide lake's small shape factors and fine maximum particle sizes of in current laboratory tests.The independent variables selected are different upstream inflow rates,initial shapes of the spillway,and maximum reservoir water volume.A model test method is employed to analyze the collapse process,peak flow,and dam erosion rate.The results show that the upstream inflow rate is positively correlated with the timing of peak flow,with higher inflow leading to earlier peak flow.The triangular spillway,due to its greatest erosion intensity,results in the highest peak flow and earliest occurrence time within the group,while the trapezoidal spillway has the lowest peak flow and latest occurrence time,with the rectangular spillway falling in between.Coarse particles help delay the longitudinal failure of the dam under small shape factors,but this delaying effect rapidly diminishes as the shape factor increases.A larger shape factor of the landslide lake not only increases the dam erosion rate and causes significant sediment accumulation in downstream channels,but also leads to earlier peak flow occurrence and a sharp increase in peak flow.

Abstract:Typhoon-induced waves inflict severe damages and economic losses upon coastal regions on an annual basis.The refined simulation of the distribution characteristics of waves within ports and the wave attenuation effect of breakwaters holds substantial significance for the research on marine disaster prevention and mitigation.To precisely simulate the impact of typhoons on waves in ports and the wave attenuation function of breakwaters,the sea area of Dongpu Fishing Port in Shishi City,Fujian Province is designated as the research domain.With the super typhoon “Nepartak”(No.1601)as an illustrative case,the Holland model is used to calculate the typhoon wind field.Based on the unstructured triangular grid,the SWAN model and the ADCIRC model are integrated through the nesting approach of large and small areas to dissect the distribution traits of waves both inside and outside the fishing port during the typhoon episode.The results showed that the constructed computational model is favorably validated by the measured data.The average error between the empirical wind field model and the measured data is restricted within 8%,and the average error between the significant wave height and the measured wave height is confined within 15%.During the transit of the typhoon,conspicuous disparities in waves are observable inside and outside the fishing port.Owing to the shielding effect of the breakwater,the inner harbor basin of the fishing port possessed a certain wind sheltering capacity.The average wave height reduction ratio of the breakwater attained 90%,manifesting an evident attenuation effect of the breakwater on typhoon waves.

Abstract:Addressing the issues of poor visibility and high elevation at the forefront of the wave wall on the top of the embankment,an experimental study on the wave forces acting on the embankment wave wall under irregular waves is conducted through physical modeling tests.The horizontal wave forces and uplift forces on the wave wall are systematically measured under different wave parameters,water depths,and wave wall positions,and compared with the calculated values obtained from established formulas.The experimental results indicate that,under the test conditions,the relative pressure exerted by irregular waves on the wave-facing side of the wave wall initially increases and then decreases as the relative height of the wave wall increases,peaking at a relative height of approximately 0.5,with no discernible pattern in the distribution of relative pressure at the bottom.Due to the wave dissipation effect of the revetment project,the measured values of total horizontal wave force and uplift force are lower than the theoretical values.The total horizontal wave force and uplift force generally increase with the increase in wave period,wave height,and water depth in front of the wall.When the relative position of the wave wall is moved backward by 0.1,the total horizontal wave force decreases by about 14%,and the uplift force decreases by about 5%.The force distribution patterns of the wave wall are summarized,providing a reference for practical engineering design.

Abstract:Pneumatic flow mixing method can be widely applied to the ex-situ solidification and resource utilization of large-scale dredged mud.However,there has been a lack of quantitative research on the impact of key process and structural parameters on mixing uniformity,leading to a reliance on engineering experience for structural design and construction.Utilizing multiphase flow numerical simulation methods,this study investigates the spatial distribution characteristics of curing agent and the variation laws of mixing uniformity under the influence of mud,curing agent,and air inlet velocity,as well as the expanded pipe diameter for both conventional and improved structures.The results indicate that under conditions that the expended pipe diameter is 200 mm and the mud inlet velocity is equal to or larger than 4 m/s,the uniformity coefficient at the outlet of the improved structure can be reduced by 50%-58% compared to the conventional structure.For the improved structure,every 1 m/s increase in the inlet velocity of mud,curing agent,and air results in an average reduction in the uniformity coefficient at the outlet of 0.26,0.70,and 0.26,respectively.Additionally,mixing uniformity improves with the increase of the extended pipe diameter and when the diameter is increased from 200 mm to 500 mm,the uniformity coefficient at the outlet can be reduced by approximately 40%.

Abstract:The pile cap joint of the high-pile wharf is an important component to transfer the upper load of the wharf.For the single pile cap joint and fork pile cap joint of the high-pile wharf,the structural deformation,stress distribution,load displacement curve,and corner bending curve are compared by finite element analysis method under different embedment depth of the pile end.The numerical results show that when the cap joint of a single pile is subjected to horizontal load,the rotational stiffness of the structure in the early stage of loading is mainly provided by anchorage steel bar of the pile core,and in the later stage,it is mainly provided by the pile core concrete and steel pipe.When the embedded depth of the pile end is less than 0.50 times the pile diameter,the joint is a semi-rigid connection.When the cross pile cap joint is subjected to horizontal load,the yield of the anchorage steel bars at the tensile side of the pile is the main reason for the decrease in structural bearing capacity.It is recommended to be strengthen in the design.When the fork pile cap joint is subjected to the standard mooring force of 30,000 t general cargo ship,the influence of pile end embedment depth on the stress and displacement of the joint is less than 14%,providing scientific reference for the design of pile cap joint of high-pile wharf.

Abstract:Long-period infragravity wave can significantly increase the movement of moored ships in ports,affecting loading and unloading efficiency,and even causing cable breaks and damage to both ships and terminals.Taking the Chancay project in Peru as an example,combined with engineering cases worldwide that are affected by long wave,study on optimization of the layout plan of the port area is carried out.Dynamic mooring analysis models are used to compare and validate different layout schemes,leading to gradual optimization.The results show that the causes of long wave are complex,and the key factors affecting mooring stability include curved coastal topography,entrance dimensions,and wave energy concentration in narrow and cornered waters.Optimization strategies include adopting fully enclosed impermeable structures,controlling entrance dimensions,minimizing narrow water areas,and avoiding zones with concentrated wave energy.The research results can provide a reference for the planning and design of port areas under the influence of long wave.

Abstract:To the actuality of land resource shortage caused by the mountainous terrain in the Wenxi operation area of Lishui Port,this article studies the relationship between the port road transportation and the rear expressway,the method of connecting the port road to the 330 National Highway,and how all relevant parties along the port road can access it.A construction idea is proposed to extend the depth of the land area through the realignment of provincial roads.After the realignment,a combination of blasting excavation and mechanical excavation is used for deep excavation of road cuttings to reduce the impact of port clearance roads on highways.Interconnections are established within tunnels to connect with national highways,and road elevation design is based on the access elevations of all parties along the route.By taking several measures under the influence of complex surrounding environments,road realignment can meet the requirements of convenient transportation,safe passage,and usage.Relevant engineering experience can be used as a reference and inspiration for similar projects.

Abstract:Regarding the design of anchorage depth under the influence of long-period waves,a study was conducted on the vertical motion of ships under wave action and the probability of bottoming out.The design conditions are determined through a detailed analysis of hydrological conditions,taking into account both wind-induced wave and long-period surges during monsoon periods.The probability design of anchorage depth is carried out using the UNDERKEEL software,and the model calculations are based on standard linear wave theory and potential flow theory.The model calculation includes the motion of the ship in 6 different directions and considers the wave forces in each direction.Under the specified acceptable probability of bottoming out,the safe anchorage depth of 200,000-ton class container ships under different wave heights and periods is calculated.Based on the calculation results,it is concluded that long-period wave with an average period of more than 13.0 s have an increasingly significant impact on the vertical motion of the anchored 200,000-ton class container ships.The analysis results of the impact of long-period wave with an average period of 16.0 s on the vertical motion of the 200,000-ton class container ships,which are not provided in relevant specifications,are also supplemented.The relevant research methods can be used as a reference for other projects.

Abstract:In flood season,between Three Gorges Dam and Gezhouba Dam,the“four beaches,one bend and one pass”of which flow is large,fast and disorderly,and the navigable flow condition is poor.On the basis of the plan of “reef blasting+slag cleaning+ dumping and filling in deep bay”of Liantuo section waterway regulation project,it is verified that whether the project has reached the expected regulation target through prototype hydrological observation before and after and actual ship seaworthiness test after regulation.The effect of engineering regulation is analyzed by observing the changes of surface gradient,water depth and surface velocity in the test reach,and then 3,000-ton and 5,000-ton class fully loaded ships are selected as test ships to carry out real ship seaworthiness tests.The test ships sail on and off the designed route,and the test ships' sailing track,shore speed,drift angle and other sailing indicators and sailing state are measured in real time.At the same time,the results of the prototype hydrology observation and the ship trial in Liantuo section are compared and analyzed combined with the measured data before and after the renovation project,and the seaworthiness performance is analyzed.The results show that the navigable flow conditions and ship navigation conditions of the river reach have been significantly improved after the implementation of the project,and the expected regulation target of the project have been achieved.

Abstract:To analyze the similarities and differences in the water and sediment transport characteristics of the South Passage and the North Passage in the Yangtze River Estuary,we conduct a preliminary study based on synchronous hydrological observation data from the two passages during the 2019 flood season.The results show that the flow velocity in the South Passage exhibits higher upstream and lower downstream,whereas maximum flow velocities in the North Passage predominantly occur in its mid-lower reaches.Salinity in the mid-section of the South Passage demonstrate higher values compared to its counterpart in the North Passage,while salinity values in the South Passage from its lower reaches to the entrance are lower than the North Passage.Vertical-averaged suspended sediment concentrations(SSC)show comparable magnitudes between the two passages.Notably,the South Passage presents smaller vertical SSC gradients,with 2 kg/m3 SSC can be transported up to 0.2H(H is water depth).In contrast,high SSC in the North Passage predominantly concentrates in mid-bottom layers.The South Passage is wide and shallow,with a stratification coefficient ranging from 0.01 to 1,indicating a partially mixed state of the water body.In contrast,the North Passage is narrow and deep,and the salinity stratification coefficient is higher than the South Passage.The stratification coefficient in the middle-section of the North Passage is greater than 1,showing a high degree of stratification.Back siltation in the South Passage channel is influenced by both suspended sediment deposition and bedload transport.Under the influence of engineering activities,back siltation caused by suspended sediments in the North Passage channel is particularly prominent.

Abstract:To the problems of crossflow and backflow exceeding the standards in the entrance area of approach channel for mountainous sharp bends,especially in sharp bend sections of mountainous area,this study uses physical model experiments to investigate the influence of diversion piers layout on navigation flow conditions in the entrance area of the ship lock approach channel.Taking the Meitan ship lock in Xin'an River as the research object,this paper comprehensively considers multiple parameters such as pier type,layout angle,pier dimensions,pier spacing and piers quantity，and focuses on analyzing the water flow state under different pier spacing and pier quantity conditions.By comparing hydraulic indicators such as longitudinal flow velocity,transverse flow velocity,and backflow velocity in the entrance area,the layout of diversion piers is optimized.The results show that the diversion pier geometry can be designed as a parallelogram,and the layout angle should be arranged parallel to the navigation channel.Additionally,the central axis of the inter-pier spacing should be arranged at an acute angle with the water flow direction.For sharp bend sections,the relative spacing between the diversion piers is set to 0.50 times the pier length,and the number of diversion piers is not less than 5.The protection range should extend to the middle section of the entrance area,which can effectively improve the navigation flow conditions in the entrance area of the approach channel for the Meitan ship lock.

Abstract:The flow dynamics at river confluences exhibit complex three-dimensional characteristics,which are further influenced by the daily flow regulation of upstream hydropower stations.These factors result in flow conditions at confluences that are more intricate than those in typical river reaches,with notable impacts on navigation at river mouths.This study addresses navigation flow conditions at river confluences affected by daily hydropower regulation,utilizing numerical simulations to systematically analyze the hydrodynamic variations at open-channel confluences under unsteady flow conditions.Using navigation-related hydraulic indices,the study examines the effects of unsteady flow periods,flow fluctuation amplitudes,confluence angles between main and tributary streams,and tributary discharge on key hydrodynamic parameters,including longitudinal water surface profiles,water level fluctuations,water surface gradients,flow velocities,and flow field distributions at the confluence.Findings indicate that the water level difference between upstream and downstream decreases as unsteady flow periods increase but rises with higher tributary discharge.Water level fluctuations decrease with increasing confluence angles and increase with larger flow fluctuation amplitudes,while the water surface gradient at the confluence increases with greater flow fluctuation amplitudes,larger confluence angles,and higher tributary discharge.Furthermore,the area of crescent-shaped high-velocity flow zones responds differently to various influencing factors during rising and falling water stages.This study clarifies the hydrodynamic processes at river confluences affected by unsteady flow conditions and daily hydropower regulation,providing a scientific foundation for understanding unsteady flow propagation in confluence zones and its implications for navigation.

Abstract:The construction of new shipping hub or the overhaul of single-line ship lock on navigable waterway often requires the suspension of navigation for construction.Setting of navigation hole in the sluice that matches the ship lock can be used as a traffic maintenance plan during the construction or overhaul of the ship lock.Taking the Paihekou regulating sluice project as an example,we propose a plan of opening the middle hole of the regulating sluice as a temporary navigation hole with a clear width of 13.3 m to meet the continuation of the existing shipping during the construction of Paihekou ship lock.In order to study the feasibility of navigation by the temporary navigation hole,we analyze and calculate the ship impact force by numerical simulation,check the anti-collision performance of the sluice,and propose the ship size and ship lock control conditions that can be navigated through the temporary navigation hole by means of full-scale ship trial and ship maneuvering simulation test.The results show that under conditions of low wind speed and flow velocity,the temporary navigation hole of the regulating sluice allows ships with a width of less than 13 m to pass through the ship lock slowly and carefully during the day.Navigation is prohibited when the wind force is above level 4 and the flow velocity is faster than 0.5 m/s.

Abstract:In order to clarify the changes in the intrusion distance and movement speed of saltwater as the flow velocity and salt concentration change,we carry out a study on the saltwater intrusion characteristics in the riverbed of Qingnian reservoir area,and analyze the influence of river inflow conditions and salinity changes on the saltwater intrusion process.We conduct experimental research by simulating the process of saltwater intrusion along the riverbed in Qingnian reservoir area in a small generalized flume.The results show that under the restriction of upstream flow,the intrusion distance of saltwater remains stable under the action of runoff,and the intrusion process is significantly affected by the tributary diversion.Due to the impact of the upstream flow on saltwater at the branch point,most of the saltwater is dispersed and flows out of the branch point,while a small amount of saltwater remains stable and continues to intrusion along the left bank.As the water depth increases,the sensitivity of the intrusion distance to the concentration change decreases.Under the same water depth condition,the increase in salt concentration will accelerate the intrusion velocity,and the shorter the intrusion time required;under the same concentration condition,the increase in water depth can significantly improve the intrusion velocity of saltwater.

Abstract:By collecting and organizing the water level data from 34 water gauges during the dry seasons in Yichang-Chenglingji section of the Yangtze River,Pearson correlation analysis and autocorrelation analysis are used to study the spatial-temporal correlation among the gauges,revealing the characteristics of water level spatial-temporal changes during the dry seasons over the past decade.The research findings are as follows:1)The water levels at most gauges in this section have shown a stable trend,with the maximum and minimum dry water level differences at Tiepu,Fanzui,and Chenglingji being more than 3.2 meters.2)The correlation coefficient between upstream and downstream gauges is at least 0.936,indicating a strong hydrological connectivity between adjacent gauge locations.3)Historical water levels in a 20-time sliding window,i.e.,within the past 7 days,have a significant impact on the current water level.The research outcomes can provide reference for understanding the dynamic changes in the hydrological environment of the middle reaches of the Yangtze River,and are of great significance for water resources management and flood control and disaster reduction.

Abstract:The section of Xijiang from Jieshou to Zhaoqing is located in the Guangdong section of the Xijiang Shipping Main Line.The river shape is winding and varied,with locally dense shoals and reefs.Since the 1990s,after several regulations,it has been able to accommodate ships of 2,000-ton class.The 3,000-ton class waterway expansion and upgrading project was implemented in 2016,taking engineering measures such as dredging,removing the reef,and encrypting spur dike of the “Sitan” section(Jieshou,Panlong,Xintan,and Dule shoals)that obstruct navigation.Analysis of measured data and mathematical models shows that the engineering measures have unblocked the main channel,realizing navigation depth greater than 4.5m for the entire waterway.The water level of the “Sitan” section has decreased by an overall 0.20-0.49 m under different characteristic flow rates,with an average water surface gradient of only 0.013‰-0.053‰.The change in water flow velocity is between -0.23 and 0.34 m/s,and the angle between the water flow direction and the main axis of the channel in most sections is less than 10°.The navigation conditions of the channel have been significantly improved,and the management goal of 3,000-ton class channel has been basically achieved.The research results can provide references for further capacity expansion and upgrading of the river section or for channel regulation under similar characteristic conditions.

Abstract:Heshangtan is a typical navigation-obstructing reef section in the river section from Fuling to Fengdu.On both sides of this section,reefs are distributed,the shoreline is extremely irregular,the water flow is rapid,the gradient is large,and the flow pattern is chaotic.Marine accidents occur frequently,which has become a bottleneck restricting the overall navigation efficiency and safety of the 4.5 m deepwater channel in the reservoir area.By analyzing the hydrological characteristics and navigation-obstructing features of the Heshangtan section,a regulation scheme for clearing the reefs at Heshangtan and Guojiazui is proposed,and a two-dimensional plane flow mathematical model is used to simulate and evaluate the effect after the implementation of the scheme.The results show that the reef clearance engineering effectively widened the river channel,improved the flow pattern in the navigation channel,significantly reduced the intensity of cross-flow and backflow,and improved the safety and efficiency of navigation.After the reef clearance,the width of the upstream navigation route in the Heshangtan section is widened from 35 to 75 m,and the self-propelled upstream flow rate is increased from 180 million to 304 million m3/s,and the navigation conditions in the section are significantly improved.The research results can provide reference for the channel regulation of similar complex river sections.

Abstract:The Guichi waterway in the lower reaches of the Yangtze River is a three-branch river section.After the implementation of the Anqing Phase II project,the goal of maintaining a water depth of 6 meters was achieved.However,there are still problems such as insufficient restrictions in the north port,weak hydrodynamics in the middle and north ports,and insufficient water depth of 8 meters at the entrance and exit of the main channel between the two ports.Therefore,a combined approach of theoretical analysis and physical model experiments is adopted,based on the concept of restricting the development of the northern port,increasing the diversion ratio of the middle port,and regulating the flow velocity in the shallow area,the engineering effects of different schemes were compared and analyzed through model experiments,and a preliminary regulation scheme is proposed.After the implementation of the project,the goal of stabilizing the waterway of the middle port,increasing the hydrodynamic and shallow scouring effects of the main waterway can be achieved.After the implementation of the combination plan,the maximum increase in the diversion ratio under the regulation flow is about 3%,and the maximum increase in shallow flow velocity at the inlet of the middle port is about 0.20 m/s.

Abstract:In view of the problem of real-time assessment of structural safety caused by over-grade berthing at the wharf(the current static detection technology has problems such as response lag and insufficient displacement resolution),a real-time deformation measurement method of hydraulic structure during the ship berthing process on the basis of video-image is proposed,aiming to solve the problem of real-time matching between the dynamic characteristics of the ship and the dynamic response of the structure.The ship berthing speed is calculated by YOLOv5 object detection and DeepSORT object tracking.The berthing angle is calculated by combining the Canny edge detection and contour detection algorithm with the minimum circumscribed rectangle method.The deformation amount is obtained and the reaction force is calculated by the video image monitoring method.The results show that the average error of berthing speed calculated values is ±0.165 kn.The error of berthing angel calculated values is ±0.3°.The relative error between the counter-force calculated values and the counter-force measured values is 7.67%.All the calculated values meet the requirements of practical applications.The ship berthing safety assessment technology based on video image analysis proposed in this paper shows high efficiency and accuracy in both detection and assessment,and can provide comprehensive,real-time and accurate monitoring and assessment for wharf berthing safety.

Abstract:Aiming at the problem of online monitoring of the obstruction flow state on the Shipai curved section,the application of image target detection is studied.The existing target detection algorithms are rarely used in the field of flow state recognition.Therefore,the flow state feature data are collected in the target section,and the surface obstruction flow state dataset SOFSD is self-made.To ensure the detection speed and accuracy,based on the YOLOv5s framework,combined with the CA(coordinate attention)and the BiFPN（bidrectional feature pyramid network）the YOLOv5s-CA-BiFPN model is constructed,and a new intelligent recognition method for the obstruction flow state on the channel surface is proposed based on the model.The experimental results show that the YOLOv5s-CA-BiFPN model improves the accuracy and recall rate by 2.3% and 0.8% respectively compared with YOLOv5s,and the mAP@0.5 is increased by 1.3% and mAP@0.5:0.95 is decreased by 2.2%.It is superior to YOLOv5s in both detection effect and generalization performance,effectively reducing missed detection and false detection,and improving the small target detection ability.Finally,an intelligent recognition system for obstructive flow on the waterway surface is constructed based on this method,which can provide reference for the construction of smart waterways.

Abstract:In view of the current problems of low efficiency,incomplete design tool chain,and poor systematicness in the design of inland waterway engineering,research on the development and application of design modules for inland waterways is carried out based on BIM technology.Secondary development is carried out using OpenRoads Designer,and through the preset template generation rules,the function of parametrically establishing waterway and revetment section templates has been realized.The revetment structure types cover the commonly used gravity,slope,and pile foundation structures in inland waterways.By establishing a comparison table of waterway mileage sections and section templates,the one-click generation function of waterway models is realized.By slicing the three-dimensional BIM model,the statistical function of the dredging and embankment backfilling quantities by the section method has been achieved.Combined with the method of custom annotations,the function of batch automatic drawing the cross-sectional diagram of waterway dredging has been realized.Using WFP interface technology,a modular and process-oriented digital design system for inland waterways has been formed.The system has been applied based on specific projects,the conclusion shows that using this system can save 30%-50% of manpower in the design stage.

Abstract:In the calculation of creep in soft clay using element models,model parameters exhibit significant variability under different consolidation pressures and show high sensitivity to soil physical indices and stress states.This necessitates extensive parameter calibration and multiple iterative adjustments,making direct application in engineering with difficulty.To address these issues,we focus on a sea reclamation project to investigate the creep characteristics of soft clay at varying depths through one-dimensional consolidation creep tests.Then we employ the generalized Kelvin model to fit the creep test curves,and carry out a normalization analysis to propose empirical formulas for five parameters within the model.The results show that the normalized Kelvin model features simplicity in parameters and strong applicability.The parameters can be fitted using indices such as consolidation load,gravity density,void ratio,liquid limit void ratio,and depth.Compared with the Burgers model and the Singh-Mitchell model,the Kelvin model better fits the experimental data,with correlation coefficients exceeding 0.98.Compared with actual engineering monitoring results,this model can effectively reflect and predict the creep behavior of deep soft foundations.

Abstract:In view of the problems of steep slope excavation,large different geological conditions and strict slope deformation control,the support and stability of high and steep slope of adjacent highway are studied.By using dynamic design method,the geological conditions such as rock formation and joint combination revealed in slope excavation are judged in real time.Combined with the safety monitoring data of slope,the support methods under different failure modes are proposed.The results show that the dynamic design of high and steep rock slope has pertinence and applicability in the case of high importance,wide range and large differences in geological and environmental conditions.It can maximize the comprehensive benefits of engineering safety,project investment and construction schedule.The relevant experience and methods can provide reference for similar projects.

Abstract:To the phenomenon of clogging and clumping easily caused by excavating clay,this study takes the excavation of clay with a rake head as the research object.Combined with the problems encountered by trailing suction hopper dredgers in the construction process of actual engineering,such as clogging rake,trapped rake,and sliding rake,the original rake head model of a large trailing suction hopper dredger is analyzed through numerical simulation of computational fluid dynamics under different working conditions,and the internal flow of the rake head and suction pipeline is analyzed,providing reference for the design of nozzle angles and nozzle arrangements in high-pressure flushing of the rake head.The results indicate that when the nozzle angle is 10°,the impact angle of high-pressure flushing can effectively wash away the sticky areas of clay,which is beneficial for the transportation of clay.When the nozzles are distributed in a forked pattern and the nozzle spacing is 115 mm,the pressure core has a significant impact on the target surface,and the interference of high-pressure water jets and backflow on the target surface is also relatively small.

Abstract:In view of the basically synchronous implementation of the newly excavated channel and the shield tunnel,the key excavation area of the channel above the shield tunnel is studied,and the key control distance along the transverse area of the shield tunnel is given according to the ultimate equilibrium theory of the Tershaki foundation soil,the distance between the top of the shield tunnel and the bottom of the channel foundation pit,the diameter of the shield tunnel and the internal friction angle of the soil.Due to the rheological characteristics of soft clay,the excavation process above the shield tunnel is numerically simulated on the basis of soft-soil creep(SSC)model and Plaxis finite element software,and the characteristics of soil deformation at the bottom of the foundation pit and the top of the shield tunnel are analyzed.The stress release time required for the soil deformation stability is analyzed for typical projects.The results show that after soil is excavated,the uplift deformation of the soil at the bottom of the foundation pit and the top of the shield tunnel continue to increase with the extension of time until the deformation rate becomes stable.The soil stress is gradually released in 45 d after the typical engineering excavation is completed.The results can provide security for the shield tunnel to be crossed in the future.

Abstract:The mix design of C40 fine sand bored pile self-compacting concrete(SCC)is carried out,and natural pit sand with a fineness modulus between 1.6 and 1.7 is used as fine aggregate.The water-binder ratio,sand ratio,external retard and collapse preventer and fly ash replacement percentage are selected as influencing factors.Orthogonal experiment is designed for 3 horizontal factors to study the workability,cube compressive strength and setting time of self-compacting concrete.The workability of self-compacting concrete is qualitatively analyzed,and the variation law of the factors affecting the compressive strength of concrete is obtained by using range and variance analysis methods.The results reveal that the sand ratio,optimal sand ratio range and water-binder ratio range of the fine sand SCC is smaller than ordinary SCC.The replacement percentage of fly ash has a great influence on the workability and compressive strength of the fine sand SCC.Increasing the content of retard and collapse preventer can extend the setting time and increase the segregation rate.The fine sand SCC prepared with water-binder ratio of 0.33,sand ratio of 39%,external retard and collapse preventer of 7.5%,fly ash replacement percentage of 23% has the good workability,and 28 d strength of the concrete reaches 54.2 MPa.

Abstract:There are many specifications of cutter suction dredger,which are widely used,and it is of great economic value to study the factors to control its construction cost and adopt targeted measures.To optimize and minimize construction costs of cutter suction dredgers,according to the current dredging quota,the construction cost composition of cutter suction dredger is analyzed,the factors that have a greater impact on the cost are found,practical and effective cost control methods are proposed,the influence of dredger size,operational conditions,and soil characteristics on costs is analyzed in combination with production efficiency,and the optimal suggestions aregiven.The results show that fuel cost,maintenance cost and depreciation cost are the main factors affecting the construction cost of cutter suction dredger,and the construction cost of cutter suction dredger can be controlled by optimizing the construction organization plan,technological innovation,fine management,and improving the localization and intelligence of ship equipment.Taking into account the unit price composition and efficiency of the vessel,the larger ship type should be selected as much as possible during the construction process.