Abstract:Because the unmanned automatic dredging system of the cutter suction dredger covers many disciplines such as artificial intelligence,fluid mechanics,soil mechanics,dredging process,signal processing,etc.,the research progress in this field is slow,and there are few reports in the literature on the development of unmanned automatic dredging systems for cutter suction dredgers.In response to the above-mentioned problems,relying on the development process of the “Tian Kun Hao” unmanned automatic dredging system,we discuss the key aspects of the design scheme,control function,automatic dredging control mode,dredging system model and automatic dredging controller.The field test method is used to test the operation effect of the unmanned automatic dredging system of “Tian Kun Hao”.The results show that the unmanned automatic dredging system can achieve stable production and high productivity,and the productivity is improved more than 15% compared with the manual control.The unmanned automatic dredging system improves the automation technology of the cutter suction dredger and opens a new era of intelligence in China's dredging industry.

Abstract:Taking the ultra-fine sand concrete of Chittagong project in Bangladesh as the research object,we study different influencing factors on the age strength of plain concrete,such as the sand ratio,the fineness modulus of sand and the dosage of water reducing agent.The results show that the strength of ultra-fine sand concrete increases rapidly and then increases slowly with the age,3 d strength reaches more than 55% of 28 d strength,7 d strength reaches more than 70% of 28 d strength.The effect of small increase of sand ratio is not significant to the age strength.28 d strength of medium sand concrete is slightly smaller than that of the ultra-fine sand concrete.When the dosage of water reducing agent exceeds 1%,28 d strength is greatly improves.

Abstract:The bed under the erosion of the current is the place where the moving mass moves. Studying the influence of the micro-bed surface shape on the moving mass is helpful for exploring the law of the moving mass on the bed,and it has a good promotion effect on river management. After a series of tank experiments,a representative video was selected,and image recognition technology was used to mark moving objects in the video,analyze the movement law of the moving mass on the bed surface,and explore the effect of water scour on the shape of the moving mass.The results show that the direction of motion of the large particles on the bed and the direction of the water flow form an angle of less than 30° with a straight path;the movement of small particles on the bed surface is affected by the near-bottom velocity,and the aggregates will branch off the flow on the surface of the riverbed,causing the direction of small particles to change at all times.The angle with the direction of water flow is in the range of 0°~90°,and the acceleration between the two aggregates is more obvious;aggregates of different morphologies have different stability,and the aggregates can be transformed into each other.

Abstract:Nowadays,although there are a lot of research achievements on reducing and reusing dredged sediment,there are still many technical problems in dredging engineering application.In view of the difficulty of engineering application of dredging technology achievements,we analyze the dredging method,dewatering process,flocculation agent and residual water treatment,point out the reasons of difficulties in engineering application,and put forward suggestions for the management and research of dredging projects.On one hand,it is necessary to strengthen the basic investigation and treatment planning of sediment pollution in rivers and lakes,and improve relevant laws,regulations and technical standards;on the other hand,we should strengthen the research and development of equipment intelligentization and automation,promote industry-university-research cooperation,and strengthen the application of research achievements.

Abstract:Aiming at the problem of flocculation dehydration of Baiyangdian ecological dredging sediment by geotextile bags,we carry out the research and engineering verification of geotextile bags'dehydration experiments.Based on the small & medium-scale compound tests of inorganic flocculant,organic flocculant,and biological flocculant,we propose a flocculation scheme suitable for dewatering of Baiyangdian geotextile bags,and verify the dehydration performance of the flocculation scheme by the engineering implementation.We adopt the group test method,and take the floc size,floc strength,and supernatant clarity after flocculation of the sediment as evaluation indicators.The results show that when the dosage of compound flocculant is 1.5%,the flocculation effect of the sediment is the best,and the COD and TP of the residual water are significantly improved,with a reduction of COD and TP by 83.92% and 91.18% respectively.On the 30th day after the filling of the geotextile bags,the water content of the sediment was reduced to less than 55%.

Abstract:The rock integrity is not taken into consideration when classificating the dredged engineering rock by the existing codes.To solve this problem,a method suitable for dredged rock classification is sought.This paper explains the mechanism and method of the pressuremeter test and the applicability of marine survey,analyzes the relationship between pressuremeter test pressure and the strength and integrity of the rock,and concludes that pressuremeter test can comprehensively reflect the characteristics of dredged soft rock.Combined with the basic rock classification,a classification system suitable for soft rock of dredging projects is constructed.It is applied to the soft rock survey of Safi Newport in Morocco to provide data support for ship selection and productivity estimation.

Abstract:Due to the vertical installation of conventional multi-beam systems,it is impossible to accurately measure the special underwater topography such as coastal waters,docks,breakwaters,spurs,islands and reefs.In response to this problem,technical research on multi-beam tilt installation and calibration is carried out.The method of multi-beam tilt installation is used to increase the number of beams on the relevant side,and the measurement can reach the position of the waterline,so the accuracy of the water depth results can meet the specifications and engineering requirements.The whole coverage survey of underwater special topography is realized,which can provide technical support for the integrated model of water and underwater,and can be widely used in underwater detection engineering.

Abstract:To improve the piling quality of the high-pressure rotary jet grouting pile at coastal tidal flats,we carry out piling tests in a cofferdam area with and without insertion of the drainage plate respectively of a land formation project in Shenzhen.Adjusting the water-cement ratio and mud pump pressure of double pipes technology and triple pipes technology respectively,we analyze the main factors affecting the pile formation of the high-pressure rotary jet pile in the soft foundation treatment of the mudflat layer of the tidal flats,summarize the main problems during pile formation construction,and propose reasonable solutions.The conclusion is drawn that the soft foundation treatment of the mud layer on the tidal flats should be constructed by the double pipes method.Before construction,drainage plates should be set up in the construction area,and a small water-cement ratio is preferred during construction.The application of the secondary spraying process can improve the pile formation quality effectively.

Abstract:As a protective structure,the accropode is widely used in coastal and offshore breakwater projects.The prefabrication of the accropode needs to be performed in a temporary or professional prefabricated site.The number of prefabricated blocks is often large,so the improvement of block prefabrication efficiency and cost saving have become key issue.In this paper,based on the examples of the south and north breakwater projects in the Guangli Port District of Dongying Port,a portable lifting device for lifting the accropode by a loader is introduced for the block reverse movement in the prefabricated process of the accropode.Many advantages,such as small quantity,high efficiency of reverse transportation,small area occupied by the site,flexible operation,etc.,have greatly improved the transfer efficiency in the accropode site and saved construction costs to a certain extent.

Abstract:The standard penetration test blow count of the dredged mud in dredging project of Lyusi Port in Qidong ranges from 6 to 18,which belongs to 9 grade sandy soil type.By comparison,we choose the layered construction process,but the dredging mud has a large number of standard penetration test blow count,which seriously affects the production efficiency of the “Junze” dredger.We study the dredging equipment of “Junze” dredger,carry out some statistics of staged production data and effect analysis,propose the corresponding improvement measures,and compare with the effect before improvement.The results show that removing the short joints of 15° angle in cutter section can increase the equipment productivity and time utilization ratio,and reduce the fuel consumption significantly.Replacing with longer cutter teeth helps to increase the daily work quantity of single tooth,construction capacity of dredger and wear time.

Abstract:Aiming at the problem that the small cut suction dredger“Junjiang” has short mud pipeline,high speed and high load when the diesel engine operates at rated speed in the construction of the project,we analyze the matching characteristics of mud pump and standard pipeline when conveying clean water,and the matching characteristics of mud pump and short mud discharge pipeline when conveying mud,adopt the measures of modifying the working conditions of the mud pump and the pipeline respectively to reach the working point of the match between the mud pump and the pipeline,and analyze the application effect.The results show that adjusting the speed of dredge pump and using small diameter impeller can make full use of the performance of diesel engine and dredge pump,and ensure the overall economic benefits of the project.

Abstract:For the same transportation condition,the number of dredge pumps and the different speeds matching combination among pumps may affect the efficiency and fuel cost of dredge pumps.This situation is especially obvious for the dredge pumps driven by the variable frequency motor with a larger speed adjustment range.Aiming at this problem,we analyze the relevant characteristics of dredge pump,and the principle of dredge pump association and speed matching,take the fuel consumption rate as evaluation standard,and study the case of dredge pump association and speed matching under specific working conditions.The results show that there must be an optimal combination scheme of the number of dredge pumps and the speed of dredge pumps under a certain working condition,so as to save fuel oil.

Abstract:The working characteristics of diesel engine and variable frequency motor are different,which causes the difference of pump characteristic curve.We analyze the equipment characteristics of diesel engine and variable frequency motor,study the influence of variable frequency motor drive,single speed ratio gearbox and multi speed ratio gearbox drive of diesel engine,limited power drive of diesel engine on the performance of mud pump,and compare and analyze the transmission efficiency,speed range,economy and adaptability of each transmission condition for reference in dredging engineering field.The results show that the transmission efficiency of the diesel engine drive is higher than that of the variable frequency motor drive.The speed range of the variable frequency motor drive is wider than that of the diesel engine drive.The diesel engine can provide more power under the condition of medium discharge distance.The complexity,initial investment,energy utilization and safety of the variable frequency motor drive system are higher.

Abstract:The frequent malfunctions of swing winch,too small torque,and the bitten rope problem occurs from time to time,which cause the decline of ship productivity and the increase of the maintenance cost of wire rope.According to the relevant specifications and design drawings of the ship,we analyze in detail the bitten rope problem of the swing wire,and find out the causes of the problem,formulate the technical schemes 1 and 2 for the reconstruction and installation of the winch combining with the main technical parameters and drawings of the new swing winch,and demonstrate in detail the necessity of deflecting the center of the winch drum relative to the center of the bridge frame in the two schemes from the angle of avoiding the bitten rope problem.The results show that after the new winch is installed on site by technical scheme 2,the arrangement of winch wire rope during ship construction is regular without bitten rope problem,which improves the performance of the ship.

Abstract:Aiming at the influence of the swing position of the cutter suction dredger on the swing speed and swing force,we derive the swing speed relationship formula and swing force relationship formula,and establish an analytical calculation model about the anchor position coordinates.Combining with the main dimensions and angle parameters of the domestic heavy cutter suction dredger “Tiankun”,we calculate the relationship between the swing speed and the take-up speed of the swing winch,and the relationship between the swing resistance and the take-up force of steel cable respectively under the conditions of different swing widths and long distance anchor,and analyze the influence of the swing anchor position on the swing speed and the swing force in different swing widths.The results show that it is as far as possible to the anchor.When the swing width is large,the frequency of inverted anchor is appropriately increased.According to the working conditions,the swing width is appropriately reduced.

Abstract:In view of the problem of insufficient dredging depth of cutter suction dredger and the requirements of environmental protection construction,the cutter suction dredger is adapted to be reformed,specifically replacing the cutter excavating equipment at the front end of cutter suction dredger with environmental protection dredging equipment,which realizes the environmental protection dredging function of cutter suction dredger.In order to increase the flexibility of the dredging equipment operation performance,a new type of dredging equipment is developed which is located between the bridge and desilting suction head.According to the three working conditions of horizontal suspension,36 m excavation depth and 40 m excavation depth,the strength of key components of dredging equipment is analyzed.The results show that the maximum stress of the key components is 84.2 MPa and the maximum deformation is 2.5 mm,which meets the requirements of strength and rigidity,and the optimized key components meet the construction requirements.

Abstract:In view of the limited blow fill of “the third runway expansion project of Hong Kong International Airport”,which requires the use of machine-made sand for environmental protection construction,the cutter suction dredger “OeanYinghao” is modified adaptively.A sand water mixing device is installed at the front of the bridge to mix the machine-made sand and sea water,and then it is transported to the mud pump through the suction pipe of the cutter suction dredger for long-distance blow fill to realize environmental protection dredging.The sand water mixing device can be extended to the construction projects with high environmental protection requirements for hydraulic reclamation and transportation,and may guide the environmental protection relay transportation at home and abroad.

Abstract:When the cutter suction dredger has a short delivery distance,it will cause the driver (diesel engine or motor)to overload and affect the stability of the system.Although it can be alleviated by reducing the speed and installing necking,it will reduce the economics of system operation.This paper uses theoretical analysis to design the initial shape of a small impeller,calculates its performance through numerical simulation,and iteratively optimizes the final design of the small impeller.The difference between the optimized impeller and the small impeller directly using the cutting diameter is compared.The actual performance of the small impeller in clean water is tested on the actual ship,and the results of the hydraulic design are verified to be reliable.Finally,the construction parameters of the short-row dredging project using the original impeller and the small impeller for the cutter suction ship are compared.After field tests and dredging applications,it is found that the construction efficiency of the small impeller is significantly higher than that of the original impeller under short-row conditions,and the developed small impeller has achieved the design purpose.

Abstract:Clay is a soil that is widely distributed and difficult to cut in dredging engineering.To analyze the mechanism of soil failure during clay cutting,we carry out two-dimensional and three-dimensional cutting experiments on the cutting of clay with different water contents,considering the effects of different cutting angles(30°,45° and 60°)and different cutting depths(50,100 and 150 mm).The horizontal and vertical cutting forces generated in the process of cutting are measured by a cutting force sensor; pressure sensors are arranged at different positions on the surface of the cutting tool,and the soil pressure received at different positions of the cutting tool during cutting is measured;a friction sensor is arranged to measure the friction generated in the process of cutting;and the deformation and failure modes of the soil during clay cutting are observed.Based on the cutting experiment,the influence of different cutting parameters on the cutting force of clay is discussed and the mechanism of soil failure in clay cutting is analyzed.

Abstract:During the construction of cutter suction dredgers loading barge,operators frequently adjust the speed of underwater mud pump motor to stabilize the mud flow rate in pipeline.To solve this problem,the automatic speed control system of underwater mud pump motor is designed by using fuzzy -PID technology.The control method takes velocity as the independent variable,mud pump speed as the dependent variable,and suction vacuum,mud pump power and mud density as the security conditions,so as to ensure that mud velocity can be kept within the set range during barge process.Practical application shows that the fuzzy-PID control has the characteristics of fast response,accurate control and good robustness in the process of underwater mud pump speed regulation,which has good promotion value.

Abstract:Mud concentration is the key parameter of the construction output of cutter suction dredger,and the traditional measurement technology produces nuclear radiation risk and environmental pollution problems due to the use of radioactive sources.Using electric resistance tomography (ERT)technology in electrical tomography technology to conduct concentration distribution imaging of mud pipes,and using electrical conductivity to measure mud concentration,a new set of non-radioactive source measurement device for mud concentration is developed,and the application test of the device in the cutter suction dredger is carried out.The results show that the error between the new mud concentration measuring device and the sampling results is within 3%;compared with the traditional radioactive source measuring device,the reliability is improved and the environmental performance is more prominent.

Abstract:The slightly weathered rock has the characteristics of high strength and few cracks,and the excavation productivity of the cutter suction dredger is low.In order to increase the cutter suction dredger's productivity and reduce construction costs,we take the Dayao Bay channel dredging project in Dalian as an example,study the construction technology of the newly-built self-propelled heavy cutter suction dredger Tiankun to excavate hard slightly weathered rock.We analyze the influence of cutter posture,cutter tooth loss and lateral swing on productivity,and optimize the construction technology.The results show that the productivity of Tiankun is effectively improved when excavating hard and slightly weathered rock.

Abstract:Due to the limitation of shallow water depth and other factors in the construction area,the final top level of throwing area is prohibited to exceed the required level.Otherwise,the soil exceeded the agreed elevation should be carried out secondary treatment,and it requires higher construction precision to underwater throwing and filling of mud barge.Based on the dredging project in southern channel of Ukraine,we adopt mathematical model to analyze the movement of different particles under different construction conditions,and improve the positioning,throwing and filling and subsequent treatment method of the soil.The results show that the improved construction technology can effectively control the quality of throwing and filling in the construction area.

Abstract:Aiming at the problem of suspended matter diffusion in dredging construction,we research and develop the filtration materials of the three-layers composite structure of surface fiber mesh,central substrate and bottom fiber mesh,prepare the anti-fouling screen,and test and verify the performances in the actual project.The results show that the interception rate of the filter material on suspended matter can reach 95%.Under the scouring action of water flow,it can effectively prevent clogging,restore filtration effect,and improve the service life of anti-fouling screen.Using the developed filter material as curtain of the anti-fouling screen,the suspended matter decreases from 408 mgL to 56 mgL.The filtered water quality satisfies the requirements of the third class of sea water quality standard.The developed filter material can effectively avoid the secondary pollution of construction to the surrounding environment.

Abstract:An in-situ geotechnical test in flume is carried out to study the strength rule of the formation of the silty fine sand hard shell on the surface of the bottom mud in Weifang Port area,clarifying the change of shear strength and penetration strength of soil under different wave conditions and velocity conditions,searching for the internal relationship between the plate state and wave current state of silty soil,and analyzing the influential factors of the formation of iron plate sand.The results show that the greater the sudden change of wave history progress,the more the strength of seafloor soil increases;the bigger the wave height,the more the strength of seafloor soil increases;the longer the wave current action time,the more the strength of seafloor soil increases.

Abstract:Aiming at the problem that TSHD has large volume and deep draft,and it is often unsuitable for construction in shallow and narrow waters,the construction technology of the harrow suction dredger in the shallow suction and narrow waterway is studied.Through the analysis of factors such as tide,water depth conditions,harrow suction vessel characteristics,construction technology and other factors,it is concluded that the selected ship's on-line position not only needs to meet the depth requirements of the ship's dredging at the time of on-line,but also the ship's surplus water depth ensures requirements at each time period under the construction speed.The construction technology takes the surplus water depth at the bottom of the ship as the key control quantity,extends the on-line position as much as possible so as to ensure the length of the construction section and gradually expand the working face.Meanwhile,the technical bottleneck of the construction of TSHD in shallow and narrow waterway has been broken through.

Abstract:In view of the problem that the current cutter suction dredger dredging operation cannot rely on manual operation to maintain the high yield,this paper studies the control parameters affecting the yield of cutter suction dredger.By using the method of neural network prediction and maximum yield estimation,the optimal control parameters of the lateral movement control system of the dredger under different conditions are obtained.At the same time,the control parameters are compared and simulated.The simulation results show that the simulation yield is higher than that of the real ship in an effective period without boundary deceleration.The method studied in this paper can provide theoretical basis and technical reference for the automatic control of the lateral movement system in the dredging construction of cutter suction dredger,so that the cutter suction dredger can take into account different control requirements and performance constraints to stabilize the maximum output in a lateral movement cycle.

Abstract:Chinese dredging industry has been developing for hundreds of years,and dredging works has already extended to eco-environmental-protection field.However,because of the lack of environmental dredging specifications,most of the current general dredging specifications and experience are used in the calculation of engineering quantities of environmental dredging projects in the design stage,which is quite different from the actual situation of environmental dredging.The confirmation of the implementing project quantity directly influences its audit and payment,which will have a big impact on project contractor benefits.By analyzing several environmental-protection project cases,combined with the actual project quantity calculations of environmental-protection projects in the Dian Lake,according to environmental-protection dredging techniques and characteristics,the measurement method fit for environmental-protection projects are discussed to provide reference for subsequent similar projects.

Abstract:The traditional concrete or ecological slope protection structures cannot satisfy the needs of coastal protection for structural anti-wave,energy dissipation,durability and ecological requirements.Aiming at the characteristics of coastal protection engineering in Mirsarai,Bangladesh,we adopt the concrete block and ecological slope protection structure type through the comparison and selection,and analyze the technical and quality difficulties,problems in typical construction,the stability of the base trough prisms,slope blocks,ecological slope protection and structural drainage.The results show that the stable mass of the foundation and the slope block satisfies the requirements for anti-wave,and can effectively withstand the impact of sea waves during the flood season.Vegetation ecological slope protection uses the root system to reinforce the soil layer,controls the erosion of soil particles and lower materials,and plays a role of ecology and landscape.

Abstract:Taking the 6-meter-deep waterway regulation project from Wuhan to Anqing section of the Yangtze River main line as the research object,we carry out a comparative analysis of the effects,advantages and disadvantages of different detection technologies for underwater paving projects,and evaluate the detection results obtained by corresponding technical means,so as to obtain a detection method that quickly conforms to the characteristics of the construction and ensure the construction quality,ad provide a technical method and acceptance basis for the underwater paving construction.

Abstract:Weifang Port is located in the middle of Laizhou Bay.The depth of beach is shallow and the variation is gentle,and the sediment movement is active.The siltation of sediment has a great influence on the operation and maintenance of the channel.This paper establishes the tidal current model and sediment transport mathematical model for calculation,compares the results with the existing measured data,then further simulates the scouring and silting conditions of the channel to predict the back silting distribution and the silting intensity distribution along the channel.The results show the calculation results of the tidal current model and sediment transport mathematical model are in good agreement with the measured data,and the predicted annual siltation volume of the channel is about 3.913 million m3.

Abstract:In the foundation treatment of water transport engineering,plastic drainage plates are often adopted for the drainage and solidification of the sludge and soft soil.The quality of the drainage board directly affects the foundation curing effect and plays a key role for the safety and quality of the project.Therefore,the quality control of the drainage board and its construction is particularly important.There are some key points that we must pay attention to kinking,jointing,verticality,damage of plate membrane filter and the return of drainage board.This paper analyzes the causes of the return of drainage board from two aspects including the plate's self-weight and friction，puts forward measures for controlling the return of drainage board，and carries out corresponding adjustment and improvement on the site construction technology.

Abstract:The evolution of the channel of the Yujiang River has a major impact on the safety of the river dyke,the stability of river,and regime and flood prevention.Taking the reach in Guigang urban area of the Yujiang River as the research object,the historical evolution of the study section is analyzed through the measured data,and the cross-section characteristics of 24 typical sections and the trend of river bed evolution are analyzed.The results suggest that:the study reach has not changed much in the past 30 years,and the river regime is relatively stable,and all sections of the channel have erosion and siltation and the change range is small;under the existing water and sediment conditions,the river reach will show a trend of slow sedimentation in the future,and the Guigang and Guiping shipping hubs will have little effect on the river regime and changes in erosion and siltation.

Abstract:There are many shortcomings in traditional installation of the breakwater wave board,such as short operating time during high tide,the difficulty of positioning,and the poor reinforcement effect of the components.This paper introduces an improved process for the installation and construction of the breakwater wave board of a yacht club project,i.e.installing steel plates on the pier of the breakwater and installing steel pendants on the top of the wave board,and connecting them during construction to achieve unsupported installation of the wave shield.This paper also elaborates the main construction procedures and carries out the force analysis of the wave baffle and breakwater. The results show that all parameters of this lifting method meet the installation requirements.This construction process may serve as reference for the installation of other unsupported components of the breakwater.

Abstract:Aiming at the coastal soft soil foundation in revetment project of Mirsarai,Bangladesh,we apply the drainage plate soft foundation consolidation settlement method for processing,analyze the material characteristics of plastic drainage plate,surcharge plan,control points of construction quality,construction problems.Based on the monitoring data of the drainage process after setting drainage board and the variation of the settlement after full load,we use three consolidation settlement models such as Hyperbolic equation,Asaoka equation and exponential function equation to simulate the settlement data,predict the settlement trend of the foundation,and obtain the final settlement.The results show that the fitting degrees of the three methods are high,and the final settlements of the three mileages are 161.04 mm,381.68 mm and 369.80 mm respectively.

Abstract:In the construction and production process of water conservancy and water transport projects,some typical events often occur,such as the innovation of construction methods or technologies,the tackling of difficult problems,the optimization and improvement of technological process,etc. In order to make the organizational experience settle and flow smoothly in the construction enterprises,it is necessary to analyze cases and extract a general and efficient management method.Taking the improvement of eco-gabion construction technology as an example,we propose a general way to solve engineering problems by combing and analyzing the background information,problem challenges,scheme selection,effect of results,application evaluation,etc.

Abstract:In view of the problems of complicated geology,high accuracy requirements,difficult underwater operation and multiple construction processes in environmental dredging construction,we study construction progress simulation,ship dredging management,fine dredging reamer operation management,and sediment dehydration management,etc. Adopting the method of model segmentation,construction progress data,development application platform,we solve the problem of difficult management of such projects and apply it to the actual project. The results show that the application of BIM technology can strengthen and improve management methods and quality control in environmental dredging construction,which can provide reference for similar projects.

Abstract:Revetment project is characterized by long coastline distance,multiple project divisions,complex slope protection types,and large bank slope variation,and has problems such as inaccurate calculation of engineering quantities and tedious construction details.In view of the above problems,we complete the creation and editing of terrain surface,3D model of slope protection,engineering quantity calculation,and earthwork calculation based on the BIM concept,taking Ma'anshan river bank revetment project as an example,and using software such as Civil 3D,subassembly composer,InfraWorks,and the application of BIM+GIS,and form a set of application processes of BIM technology for the revetment regualtion.The research results may serve as reference for similar project construction.

Abstract:In order to meet the construction requirements of cutter suction dredger in the wind and waves,this paper makes an in-depth study on the three cable positioning control system,develops a set of automatic three cable positioning system suitable for cutter suction dredger,and successfully applies the system to Tianqi dredger.By using double PID control idea,the system can effectively control the speed loop of the frequency converter,which can not only ensure the ship to walk in the direction of the construction line in the step process,but also reduce the impact of the wind and waves on the positioning process,so as to realize the rapid positioning of the ship and improve the construction efficiency.

Abstract:In order to meet the construction needs of environmental protection cutter-suction dredgers in the treatment of rivers and lakes and improve the quality of environmental protection dredging,relying on the dredging ship in the Baiyangdian internal source control project,a set of dredging integrated monitoring system has been designed and developed suitable for environmental protection cutter-suction dredgers.The system uses technologies of sensor,measurement,communication,computer,automation to monitor the key construction data of the ship's dredging process in real time,and at the same time integrates the design of the construction plan,post-drought process analysis and remote data sharing,which effectively improves the ship environmental protection dredging accuracy and construction efficiency.

Abstract:In view of the problems such as poor integration of survey data and information,tedious updating of drawings,low visualization of two-dimensional drawings,and complex calculation of quantities in the design of waterway regulation project,BIM technology is used to create a parameterized three-dimensional model,integrate construction information,display the design scheme with BIM technology,and visualize the construction schedule.The following conclusions are drawn:1)The design scheme based on BIM technology has the characteristics of integrity,rapidity and accuracy.2)The visual expression is more intuitive,which improves the calculation accuracy of engineering quantity and reduces the risk of rework.3)It can reduce the communication cost for the construction company,assist the construction technicians to optimize the construction scheme,and provide an effective technical means for the fine management of the project.

Abstract:The main construction content of the reclamation project in Weihai inner sea is using the method of sand blasting and silt squeezing to hydraulic fill.Mechanical compaction should be adopted after the completion of hydraulic filling in reclamation area.In the process of construction,it is necessary to measure the progress of the reclamation area for many times,and the calculation frequency of earthwork volume is relatively high.In order to ensure the accuracy of earthwork volume calculation,we compare different earthwork volume calculation methods of South CASS software,and select the reasonable calculation methods based on the actual situation of the project,so as to provide basis for project quality and schedule control.The results show that selecting the appropriate calculation method can accurately calculate the earthwork volume,and reflect the actual situation of the site vividly.