Abstract:In view of the increasingly serious phenomenon of tidal flats erosion caused by the continuous decrease of sediment coming from the Yangtze River,we emphasize the importance of the protection of the Yangtze Estuary tidal flats.Taking the Jiuduan Shoal and the Hengsha East Shoal as examples,we probe into different protection measures to be taken for different shoals.The conclusion is drawn as follows:the tidal flats in ecological preserved areas shall be protected by changing the peripheral environment to promote the gradual accretion of the tidal flats,while the tidal flats in the non-ecological preserved areas shall be protected by initiative measures and works to cultivate a tidal flat in a high-medium-low ordered shoal shape,to improve the ecological quality of the tidal flats and enhance the regional functions of the tidal flats on the basis of realizing the stability of tidal flats resources,and actively respond to the state strategy of the Yangtze River Protection.

Abstract:The ecological bank revetment using the sash structure to stabilize the soil is a new trend of bank revetment projects.The ability of the sash to stabilize the soil is a key part of the success of the ecological bank revetment construction.This paper introduces the multi-grid block,a new type of eco-revetment hexagonal block,and studies the erosion depth of the sediment inside the block cavity after wave action through indoor water tank experiments.The test results show that the depth of sediment erosion in the multi-grid block on the slope embankment follows the rule of increasing and then decreasing from top to bottom along the embankment.At the same time,the depth of sediment erosion will increase as the wave height increases.And the depth of sediment erosion in different parts of a single block is different.Changing the type of sediment filled in the block cavity will affect the depth of erosion but not the overall law of erosion on the slope.Compared with the frame grill fence board,the multi-grid block has a better sand-fixing effect,and can provide a good growth environment for plant revetments.

Abstract:The bichromatic waves propagation into a narrow-long harbor excites low-frequency oscillations inside the harbor,and the influence of wave secondary reflection on the wave maker is reduced due to reasonable arrangement of physical model experiment.Concurrently,reasonable experiment layout reduces the influence of wave re-reflection on wave maker.Fast Fourier transform and wavelet transform are adopted to investigate the amplitude-frequency response of different bichromatic waves and the distribution of wave energy in time-frequency domain.The non-linear interaction process between different components of waves is also investigated by employing the wavelet-based bispectrum. The results show that:when the short wave of bichromatic waves has different resonance frequencies corresponding to the harbor,the sub-harmonic frequency wave amplitudes generated by wave nonlinearity are different in the harbor;when the short wave of bichromatic waves corresponds to the lower resonance frequencies of the harbor,the waves would gather more energy in the harbor;the non-linear transfer processes of wave energy are revealed between sub-harmonic frequencies and superharmonic frequencies in wave components and the short wave frequency.

Abstract:Based on the project of Shenzhen—Zhongshan linking with deep cement mixing method (DCM) foundation treatment,we carry out the indoor mix ratio test of the marine soft soil layer,and analyze the effects on the strength characteristics of cement soil,including the soil layer properties,cement content,age,cement soil moisture content,as well as the cement soil density.The test results show that the cement hardening effect of the marine soft soil layer in the engineering area is significant.The strength of cement soil in 56-day age is above 2.0 MPa,and the cement content suggested would be higher than 260 kg/m3 in DCM treatment.The moisture content and density of cement soil basically remain unchanged during the hydration reaction,which mainly depends on the physical properties of the undisturbed soil and causes the cement soil strength difference.Furthermore,based on the test results,we establish a cement soil strength prediction formula for each layer of soil,and verify the validity of the strength prediction formula by comparing the measured and predicted strengths of the cement soil strength on the south side of the project site.

Abstract:The layout plan of the encircling breakwater is verified by means of the overall physical model test.The results show that:1)The wave peak line in the harbor basin is deflected and the wave energy is concentrated,which results in that the local mooring conditions of the wharf do not meet the standard requirements.When the position axis is rotated 15° clockwise and arranged in parallel with the wave crest line,it meets the requirements.2)According to the standard of whether the wave crossing the embankment hits the wharf axis in the harbor,three elevation shielding functions of 10.0 m,10.5 m and 11.0 m are tested,and the 11.0 m elevation is feasible.3)The 6 t armor block outside of breakwater is unstable,and 10 t armor block is stable after many times of optimization.It is also found that lateral wave forces acted on the linked armor block at the arc turn is more dangerous than the positive wave force.4)The test results are compared with the calculated values of the standard formula,and the test results are all large.Therefore,attention should be paid to the treatment of arc turn section,and the relevant provisions of the axis-included angle required by the standard should be followed.5)The test also verifies the necessity of the physical model test of the three-dimensional harbor basin in terms of block stability,overtopping rate and optimal design.

Abstract:The propagation of waves through permeable structures is a non-linear process of wave-wave interactions,which is difficult to accurately simulate with mathematical models.In view of this problem,four types of submerged breakwaters,rectangular,trapezoid,triangle and semicircle,are selected to study the wave resistance performance of these four types of submerged breakwaters by wave section physical model test.The commonly used influencing factors are selected,and the variation law of the transmission coefficient under the action of the waves with these influencing factors is analyzed.The experimental results are verified by empirical formulas.The results show that the wave resistance performance of submerged breakwaters is greatly affected by factors such as incident wave factors,the water depth above the submerged breakwaters and the size of the submerged breakwaters.

Abstract:In order to alleviate the dredging pressure of Shenhua Huanghua Port and reduce the cost of dredging,we carry out a feasibility study on the application of navigable depth in the harbor basin and inner channel of Shenhua Huanghua Port.Based on the test of density,particle size,hydraulic characteristics and rheological behavior of the sediments in the inner channel and the basin,we demonstrate the feasibility of applying navigable depth,and put forward the navigable silt density value of the basin and inner channel of Shenhua Huanghua Port.Furthermore,by investigating the distribution of navigable resources,we analyze the key areas and prospects of applying navigable depth to provide a basis for guiding the utilization of navigable depth in Shenhua Huanghua Port.

Abstract:Fender is the interface between on-shore structures and ship,avoids the collision of ship hull during berthing period,and protects the marine structures from damage.A complete fender design should include several alternatives.The determination of fender selection has a crucial impact on the jetty design and affects the design loads directly.The paper aims at carrying out a case analysis of fender selection based on the Russian standards,and comparing with the national standard in order to provide design reference for port designers.

Abstract:We carry out the compression-bending test on three groups of grouting joint specimens of prefabricated wharf,study the mechanical behaviors of grouting joint specimens such as bearing capacity，ductility and failure mode with different grouting length and grouting thickness.The results show that the specimens of the grouting joint have better ductility and higher bearing capacity.The failure mode of the grouting joint under compression and bending is the buckling failure of the steel tube.As the length of the grouting joint increases,the bearing capacity increases.The increase of grouting thickness has little effect on the bearing capacity of the component,but the increase of grouting thickness can improve the crack resistance of the bottom of the grouting body.When putting this structure into practice,it is better to raise the grouting thickness properly.

Abstract:In order to enhance the stability and structural safety of the protection of deep-water breakwaters under severe sea-conditions,we optimize the protection structure of the original design of the breakwaters according to the latest regulations and experimental researching results.We use double-layer twisted-Wang block surface protection structure,apply the artificial blocks instead of super-heavy-size blocks,and propose the critical points of construction quality control measures.The results show that the double-layer twisted-Wang block surface protection can solve the problem of large-scale stone supplying and improve the stability of the deep-water breakwaters protection structure.

Abstract:The majority of the overseas port construction projects are located at areas with swell.The stability of the breakwaters under swell action is not fully known and researched.For the rubble-mound breakwater,the armour layer is very important,and also the toe of the rubble mound breakwater is important.Taking a breakwater project of a certain port as an example,the 2D and 3D physical model tests are performed to study the stability of the toe rocks of the rubble-mound breakwater under swell action.Based on the test results,the stability of the toe rocks of the rubble-mound breakwater under perpendicular and oblique wave action is compared.The damage of the toe rocks in the roundhead under oblique wave action is analyzed specially,and the damage level with the incident wave periods and water levels is also analyzed,thus the original plan of the toe rocks is optimized.

Abstract:Based on the three-dimensional wave physical model test,this paper studies the mechanical characteristics of the berthing pier under the cover of the slope dike,and analyzes different influences of wave overtopping height and various wave directions on the wave force acting on the breasting dolphin protected by the rubble breakwater.The results show that:1)When the wave propagates to the rubble breakwater,some of the wave is breaking and over the breakwater impacting on the breasting dolphin directly,while the other part of the wave will bypass the breakwater and forms the diffracted wave behind the dike to impact on the breasting dolphin.2)Due to the violent vertical wave impact,the vertical wave force acting on the berthing pier is larger than the positive wave force and transverse wave force.3)With the increasing wave overtopping height,the vertical wave force and positive wave force on the breasting dolphin increase significantly,but transverse wave force has no obvious increased trend.Meanwhile,the bigger wave overtopping height will also cause the ratio of vertical wave force to transverse wave force to increase.4)Different from no significant distinguish of wave force between positive wave and oblique wave for small wave overtopping height,oblique wave can produce larger wave load when the wave overtopping height is large.As well,the oblique wave can strengthen the wave diffraction and decreases the rate of positive wave force to the transverse wave force.

Abstract:Jingtang Port is the first deep-water port built on the sandy-silty coast in China. Since its completion in 1992,there have been many times of sudden siltation in channel. In order to master the mechanism of sudden siltation and summarize the experience of building a port on the sandy-silty coast,we analyze the coastal dynamic conditions and characteristics of the sudden siltation in channel,and point out that there is a wide surf zone and “generalized littoral transport zone” under the strong wind waves. The main reason of channel’s sudden-siltation is the strong wind waves in autumn and winter,which move and transport the silty sediment in offshore area. It is the key to estimate the sudden siltation in the channel of silty beach to master the movement law of silty beach sediment under strong wind waves,especially the characteristics of high concentration of bottom layer. The research results may serve as reference for the site selection of port construction at sandy-silty beach and the construction of sand retaining dike.

Abstract:Multimodal transport is the development trend of modern logistics,the key of which is the ability matching and smooth connection between different transport modes.Wharf is the interactive point of sea transportation and land transportation，so some wharves introduce railway into wharf to carry out multimodal transport,but the disconnection of railway to road transportation causes new problems.The traffic chaos,the conflict between container truck flow and the municipal traffic flow in harbor are the problems to be solved urgently in many wharves.The development of air-rail system provides new ideas and methods for solving these problems.Based on the development status of the air-rail system and the container supply structure and business demand of Qingdao port Qianwan port area,this paper studies the application of the air-rail system in the wharf from the practical level,analyzes the difficulties and solutions of the combination of the air-rail system and the wharf business,and provides reference for the wharf to adopt the air-rail system.To solve the problem of intermodal transport connection and port surface traffic congestion,air-rail is also a technical solution for other terminals.

Abstract:Aiming at the problem of damage identification of high piled-wharf,the paper introduces the quantum behavior optimization BSO(beetle swarm optimization),constructs the objective function by using the difference of structural modal parameters (natural frequency and mode shape),and proposes a damage identification method based on the QBSO (quantum beetle swarm optimization)algorithm.The single damage of single straight pile or single fork pile,double damage of double straight pile,double fork pile or straight pile+fork pile in a high piled-wharf model are calculated by the proposed method,and compared with BSO algorithm and PSO(particle swarm optimization) algorithm;the single damage of single fork pile after adding noise to vibration mode shape is calculated.The results show that the proposed method can identify the location and degree of damage quickly and accurately,with high computational efficiency,fast convergence speed,good stability and noise resistance.

Abstract:The pile foundation of high-piled wharf built in the marine environment changes the original path of water particle movement and the shear force of water flow,which can cause the movement or scour of soil particles on the seabed.The scour is a threat to the stability of the structure and foundation.This paper calculates the local scour of high-piled wharf by five commonly used formulas at home and abroad,and compares with the measured values of the project.The results show that the wave and tidal current are superposed to get the velocity of the wave-current interaction,and it is feasible to calculate the local scour depth of piles in the proposed project area by using the formulas of Han Haiqian and J & S.

Abstract:The displacement based seismic design method is often used in the seismic design of suspended jetty structure in the highly seismic zone.The sulfate-reducing bacteria (SRB) can cause serious corrosion to steel pipe piles in a very short period of time.Three main anti-corrosion measures are proposed for the corrosion mechanism of SRB,and three different engineering application options of physical anti-corrosion method are compared and studied.Based on the design of a container terminal project in Manila,Philippines,we carry out the push-over analysis for the three options respectively by using the control variable method.Results show that the coating protection option and the partial concrete infill option have a better structural ductility and larger structural resistance,and may serve as reference for the structural design under similar engineering environment.

Abstract:The high pile wharf built in 1970s and 1980s is easy to rust and expand of beam slab reinforcement in splash area due to the long-term chloride corrosion environment,which leads to the longitudinal cracking and falling off of concrete.In order to ensure the safety of the wharf structure,this type of beam needs to be repaired and reinforced.Based on the actual wharf repair and reinforcement project,we introduce two kinds of repair and reinforcement methods including enlarging beam section and pasting carbon fiber cloth,and carry out the comparative analysis of the two methods from four aspects of application scope,construction efficiency,quality and cost.The results show that enlarging section method is more suitable than pasting carbon fiber cloth method,but pasting carbon fiber cloth method has obvious advantages in construction efficiency,cost,construction difficulty and quality controllability.

Abstract:Interlocking block paving is widely used in the port area.After investigation,we find that the quality of interlocking block paving in various ports in China is uneven.In view of this situation,we compare the standards of the quality control and testing of the interlocking block pavement in China and Britain,and obtain their similarities and differences.The results show that although the Chinese and British standards have similar requirements for the appearance quality and size,strength and physical performance of the interlocking block,their sampling inspection methods are different.Chinese standards lack some parameter requirements for construction quality control,and there is no clear regulation on the initial maintenance and overhaul requirements of the pavement.Therefore,we supply the missing part of the Chinese standards to provide a reference for the revision of the interlocking block construction standard.

Abstract:Owing to the flow confluence at the mid-channel bar tail in the anabranching channel of mountain river,the oblique flow may cause the obstacle to navigation.In order to reveal the influence of the oblique flow on the safety of navigation,the MIKE 21 hydrodynamic model is used to analyze the hydrodynamic characteristics and engineering improvement effects of the confluence area before and after the channel regulation project based on the existing physical and ship model experiments of the Dafutan navigation and power hub in Yuanshui River,a tributary of the middle Yangtze River in China. The results show that during the dry season,the oblique flow of the navigation in the confluence area exceeds the standard due to the high flow velocity in the right channel and the angle within the route.The longitudinal dike or spur dam constructed at the bar tail can reduce the impact of the oblique flow. Nonetheless,given that a longitudinal dike or spur dam parallel to the route is arranged at the bar tail,the magnitude of the oblique flow and back flow of the route increases the range of oblique flow distribution and is still beyond the standard value.Combining various engineering measures such as adjusting the shipping route,dredging the shallow area of channel,deflecting the longitudinal dike,and the overall arrangement angle of the spur pier can ensure that navigation flow at the bar tail meets the requirements of the norm.

Abstract:Based on the analysis of the navigation status and current river regime evolution of the north channel in the Yangtze River estuary,this paper points out that water depth deficiency in the mouth bar section is the main factor affecting the navigation conditions in the north channel.The regulation project scheme of the north channel should consider the relationship and influence of surrounding water projects,flood control and damp proof,water resource utilization and ecological environment protection.This paper applies the flow mathematical model to evaluate the regulation effect of the scheme.The results show that the channel regulation effect is good in terms of flow field dynamics,the channel planning objectives can be achieved by dredging.

Abstract:For the seepage failure of sility channel bank slope due to continuous rainfall,the measures of inverted filter and seepage-proofing wall are usually adopted.In view of a channel bank works in north area of Jiangsu,the prestressed concrete pile wall is proposed to be a seepage-proofing wall measure,and the application effect of seepage-proofing wall in different positions is analyzed numerically.The results show that when the pile seepage-proofing wall is set in some distance behind bank retaining wall and in some depth into soil,the seepage path is effectively extended and the slope displacement caused by rainfall infiltration is substantially reduced,so the bank stability is guaranteed.

Abstract:In the middle and lower reaches of the Yangtze River channel regulation,the beach protection engineering with soft mattress as the main part is easy to cause beach surface hardening.In order to improve the habitat conditions of beach consolidation area,we propose an ecological channel construction technology combining the utilization of dredged soil and the protection of the beach based on the soil consolidation effect of hydrophilic vegetation,which is used in the engineering design of the second stage of waterway regulation from Xinzhou to Jiujiang channel.This technology uses the dredged soil to lift the beach surface,introduces the local flood resistant and hydrophilic vegetation,applies the degradable and pollution-free natural materials to assist in soil consolidation and erosion control,so as to ensure that the pioneer vegetation can develop stably to sufficient abundance,and finally achieve the stability of the beach.

Abstract:The door water delivery is an important characteristic of triangular gate.Based on the door water delivery of triangular gate,the low water head ship lock may not be equipped with the valve to reduce the engineering construction cost,but it is still difficult to grasp the specific applicable conditions.Based on the Daliuxiang ship lock without a valve,by use of the method of combining the theoretical calculation with the site factual measurement,the water power and the opening and closing force under the door water delivery have been analyzed.The study shows that:the larger the entrance is,the smaller the water head of the triangular gate which can bear the door water delivery is;at present,the relevant calculation formulas for the door water delivery still need to be combined with the structural characteristics of the triangular gate to determine the flow coefficient;in addition to the calculation of standard formulas,the influence of the door body gap flow and inertia resistance moment shall be also considered by the opening and closing force of triangular gate.

Abstract:The river regime and combination of flood conditions are complex from Linhuaigang to Lutaizi section of main stream of the Huaihe River,which increase the channel regulation difficulty.In order to optimize the channel regulation project of this section,we establish a two-dimensional hydrodynamic mathematical model of the river channel according to the characteristics of the river section,calibrate and verify the model by multiple floods,determine the flood combination of “mainly in the main stream of the Huaihe River” as the most unfavorable flood combination for Liutaizi channel,and simulate the flow field of the current channel,the schemes of 480 m and 550 m bending radius to compare and analyze.The results show that in terms of flow pattern and lateral velocity,the scheme of 480 m bending radius is better than that of 550 m bending radius.The main stream of Huaihe River has a large width of water surface,and the channel bending radius can be appropriately reduced by increasing the width of navigable water area.The scheme has the advantages of changing little to the original channel,stable river regime,flowing smoothly and saving investment.

Abstract:Aiming at the key issues such as the comparison and selection of the digging port layout plan and the optimization of traffic layout in the graphic design of an inland port,the sediment and traffic digital simulation and BIM technology are used for modeling,calculation and analysis,and the siltation and plane traffic organization of different schemes are obtained.The plane transportation organization situation provides scientific methods,reliable data support and visualization means for the comparison and selection of port schemes and transportation layout optimization,which improves the science and communication efficiency of the design.

Abstract:Aiming at the problems existing in the integration and model sharing of surveying and mapping elements in the process of waterway BIM design,we propose a BIM-based integration of surveying and mapping elements and a method to realize the sharing of surveying BIM models based on special intermediate file format and common data model format. Through the engineering case analysis,we expound the technical route of BIM technology in the integration of surveying and mapping elements and the transfer and sharing of surveying and mapping models.The results show that the integration of surveying and mapping elements based on BIM technology and the sharing of surveying and mapping models have advantages,and the research results can provide reference for carry out BIM surveying and mapping work.

Abstract:In view of the problems existing in the traditional design method for the plane lift gate,such as complicated process,time-consuming and laborious,tedious change and inefficiency,we take the plane lift gate in the shiplock and waterway engineering of Cao’e River as an example to probe into the application of Autodesk Inventor in the establishment of three-dimensional model,the generation of mechanism transmission animation,the inspection of structure interference,the display of the center of gravity of the gate,and the two-dimensional engineering drawing. The result shows that the application of Autodesk Inventor software in the practical engineering can greatly shorten the design cycle,improve the design efficiency and accuracy,and may guide the design of other types of gates.

Abstract:Vacuum preloading is a widely used soft soil foundation treatment technique.Aiming at two new processes including overpressure vacuum preloading and thermal consolidation vacuum preloading,the two new processes are analyzed and discussed based on field test and engineering cases.The results show that the high pressure gas filled into the foundation by overpressure vacuum preloading cannot change the soil saturation state,but may reduce vacuum degree and prevent vacuum degree from transferring to the deeper layer along the prefabricated vertical drains (PVD).The reinforcement effect of overpressure vacuum preloading is quite different,the trial construction should be done to verify the reinforcement effect before practical engineering application.The thermal consolidation vacuum preloading increases the soil temperature,which can improve the permeability coefficient,shorten the consolidation time and increase the consolidation settlement,so it is especially suitable for soft clay or sludge.Focusing on the difficulty in the field application of thermal vacuum preloading,the new advances such as new kind of thermal PVD and integral solar heater for circulating water are invented to solve manufacturing difficulty and high heating cost respectively.

Abstract:The reclaimed ultra-soft soil is characterized by high moisture content,high void ratio,high compressibility and low strength,and the engineering experiment of it is essential and difficult for the investigation work.Taking the reclaimed ultra-soft soil in Dalian as the study case,we carry out standard consolidation tests of several samples with different water contents in laboratory. By studying the relationship between the moisture content and the consolidation coefficient & the secondary consolidation coefficient as well,we hope to guide the engineering practice of the ultra-soft soil foundation treatment.

Abstract:The key of dynamic consolidation method applied to soft foundation reinforcement engineering is to determine the scientific and reasonable design and construction parameters.This paper carries out the field test research of dynamic consolidation method under the condition of high groundwater level,conducts a large number of field observation and test detection,and analyzes the soft foundation reinforcement effect under two dynamic combinations according to the test results.The results show that the dynamic consolidation method is suitable for the supporting engineering,and under the engineering geological conditions,the effective reinforcement depth of 4 000 kJ ramming energy can reach about 10 m.One more time of point ramming is more conducive to improving the soil strength of the shallow layer of the foundation.After treatment,the wharf yard can meet the design requirements of settlement less than 300 mm and bearing capacity up to 200 kPa.

Abstract:The high-pressure flushing device on the drag head of trailing suction hopper dredger can be used to effectively improve the efficiency of dredging operation.The pipeline design of the high-pressure flushing device is still imperfect,and some structures need to be optimized.We carry out three dimensional modeling,simulation calculation and result analysis of a high-pressure flushing device by using numerical method,find that there is vortex flow near the inlet and outlet of the high-pressure flushing branch pipe in the drag head,and the hydraulic loss is large,which leads to the failure of the ideal outlet total pressure during the construction of the drag head and affects the efficiency.In view of these problems,we improve the flow in the pipe by using gradient pipe and circular chamfer.The results show that after optimization,the resistance loss of the high-pressure flushing pipeline of the drag head is reduced,the jet water speed is higher,the total flow of flushing water is increased by about 3%,the outlet total pressure is increased,and the soil breaking capacity is improved,so as to improve the efficiency of dredging operation.

Abstract:In order to master the deformation regularity of earth-rock cofferdam with pure concrete linked water cut-off pile,the monitoring data of earth-rock cofferdam with pure concrete linked water cut-off pile in different position of different dewatering stage for different monitoring items was analyzed and summarized.The results showed that:the deformation of cofferdam was remarkable large during the first time dewatering,but the increase trend of cofferdam deformation was slowed down obviously during the second time dewatering after refilling sea water into dock,refilling riprap at the foot of cofferdam,widening and strengthening cofferdam;the deformation of the cofferdam in the middle was largest,near landing position was slightly large and the landing position kept stable during entirely dewatering period;the increase trend of monitoring data from different monitoring items in the same position was consistent.After analyzing,the rate of dewatering 400~500 mm/d was determined as the most reasonable finally which can ensure the safety of cofferdam and to some extent speed up the dewatering making sure the construction time.

Abstract:Aiming at the problem that sea sand and river sand used for backfill behind caisson structure of gravity wharf are relatively expensive due to strict environmental protection policies and backward mining methods in some overseas countries,we apply the field test to study the construction technology of rapid compaction in depth,propose the design and construction scheme of using low-cost material from mountain with a certain mud content as the backfill material,verify the feasibility of the technology by field test,and give the best number of ramming,the safe distance of ramming and the corresponding isolation treatment measures.The results show that the rapid compaction technology can be used for backfill behind caissons of gravity wharf,which can greatly reduce the engineering cost.

Abstract:In view of the sea damaged problem of slope revetment structure with the accropode during the typhoon,the comprehensive inspection and evaluation of the revetment in the sea damaged section are carried out.Combined with the situation and reasons of the sea damage of the test section,the plan of repairing and strengthening is designed by making full use of the terrain after the sea damage,and it is verified by the physical model test.The main conclusions are as follows:the mass of the cushion block stone of slope revetment is the key factor to maintain the stability of the revetment block,and the required mass of the cushion block stone in the 2018 version of the design code for breakwater and revetment are correspondingly improved;the stability and wave overtopping amount of the revetment block under the gentle slope condition meet the specification requirements,but the relevant technical requirements for the block installation under the gentle slope condition should be paid attention to.

Abstract:In view of the quality problems of diaphragm wall,we carry out a statistical analysis on the exploration data,and make clear that the exposed reinforcement and cavity of diaphragm wall are concentrated at the joints above -2.50 m and at the joint of wall sections.The causes of concentrated distribution of defects are analyzed from the geologic conditions,foundation treatment,mud,concrete,grooving,reinforcement cage production and installation,joint pipe placement,etc. Quality improvement measures including detecting mud index and sediment thickness during concrete pouring,increasing the position and perpendicularity detection of butt joint pipe,increasing the perpendicularity requirement of forming groove,improving the protection ability of base plate,improving the stability of the upper soft soil layer and improving the joint form of wall section are put forward.