Abstract:With the implementation of the Yangtze River 12.5 m deepwater channel first stage regulation project,the 12.5 m deepwater channel right boundary of Tongzhousha east waterway to Langshansha east waterway has become stable.But the left boundary of the deepwater channel,the Xinkaisha to Kuzigangsha branch is still in the natural evolution without regulation measures.We analyze the topographic changes since the project constructed.The results show that Xinkaishasand shoal is becoming narrow and long with the sand silted at the tail.The tail of Kuzigangsha sand shoal is moving southward and invaded into the deepwater channel.A new ditch between Xinkaisha and Kuzigangsha is in developing,and the 10 m fathom line linked up in December 2015.These changes will take the negative effects to the maintenance of deepwater channel,and it is suggested that the related research on the follow-up improvement project of deepwater channel should be carried out as soon as possible.

Abstract:The foundation bed leveling for the second phase of Yizheng waterway regulation project of the deep-water channel 12.5 m below the Yangtze River of Nanjing is characterized by deepwater,large flow velocity,low visibility and small amount.The existing bed leveling methods cannot meet the construction requirements.We develop the underwater bed automatic leveling equipment.Through the design of general structure,the development of automatic leveling control system,the research of automatic leveling construction process and the application of practical project,the equipment realizes underwater bed automatic leveling construction in the complex hydrological environment.This equipment is characterized by high leveling accuracy,high construction efficiency,low cost and broad application prospects.

Abstract:Under certain conditions,shallow water waves may interact with offshore breakwaters in the form of solitary wave.In view of this phenomenon,the analytical integral solution to the reflected and transmitted solitary wave field caused by finite thickness vertical porous breakwater under action of oblique solitary wave is derived by applying the eigenfunction expansion approach,and solitary wave forces on breakwater and solitary reflected or transmitted wave surfaces are accordingly calculated，which have certain theoretical as well as application value.The results show that the variations of incidence wave angle,sea condition,breakwater surface porous coefficient and solitary wave characteristic parameter may have some influence on wave effects.Compared with Airy small amplitude wave theory under the same shallow water condition,the predicted values of wave load and the maximum wave surface of the solitary wave theory are significantly larger,reflecting the nonlinear effect of the shallow water wave.At the same time,it shows that the solitary wave model will be more reasonable and reliable under certain shallow water conditions.

Abstract:Using the internationally popular OPTIMOOR software for ship mooring analysis,systematic analysis of ship mooring stability subjected to long-period waves is carried out.The influence of period,wave height and incident angle on ship mooring stability are studied.Through the analysis of the calculation results,the influence of wave height and incident angle on the ship’s heave motion is very obvious,and the period has the most obvious influence on the ship’s surge motion.At the same time,the maximum mooring line tension and three factors of long-period wave(including wave period,wave height and incident angle)show a positive correlation in a certain value interval,and with the increase of wave factors,the mooring line tension distribution shows obvious unevenness.Moreover,maximum fender reaction and long-period wave also show a positive correlation in a certain value interval.For the two wave factors of period and incident angle,the larger the value are,the more balanced the four groups of fender reaction will be.

Abstract:At present,no standards can be followed for the overtopping calculation of the composite seawall with a berm in the domestic.The seawall structure with a berm placed on the wave-facing side is more common during the practical seawall construction,and it is very necessary to provide a reference for the seawall structure design.We summarize several methods for calculating the overtopping discharge in the worldwide,and obtain the relationships between the overtopping and the influence factors such as the relative crest freeboard,water depth on platform,platform width and height of storm.Combined with the comparison of physical model test data from the composite seawalls with various structural types,we recommend EurOtopII and Chenguoping’s formulas to calculate the overtopping discharge of composite seawall structure,then compare and check the results.

Abstract:One of the important preconditions for engineering practice of deep cement mixing method is to conduct mixing ratio experiment for cement-mixing soil.Based on a large amount of laboratory experiments,we propose two different sampling methods for cement-mixing soil,i.e.,dry soil sampling method and wet soil sampling method,and corresponding test procedures,and compare the advantages,disadvantages and applicability of each method.It is concluded that:1) dry soil sampling method should be adopted for experiments in which the objective water content is variable,or smaller than the initial water content;2) wet soil sampling method is more suitable and efficient when it aims to study the effects of other parameters on the strength of cement-mixing soil with initial water content.Taking the alluvial clay from Hong Kong as a research object,we study the effect of water content on the unconfined compression strength of cement-mixing soil by mixing ratio experiment with dry soil sampling method.The results show that the strength of cement-mixing soil decreases as water content increases,and when the water content is more than 70%,the strength increases slowly with the increasing curing period.

Abstract:Geotextile tubes are widely used in the fields of shore reclamation,protection of river bank and coast and port construction.Some experimental tests of geotextile tubes are conducted to investigate the bearing capacity of geotextile tubes,the tension of geotextile tubes,filing materials,as well as permeability and drainage,but the whole process analysis of filling consolidation and the consolidation laws of the geotextile tubes are not recognized.A model of geotextile tube is designed to monitor the pore pressure and soil pressure in the whole filling process. The results show that:1)the pore pressure and soil pressure alternate with the change of the filling and dissipation.The upper and lower horizontal earth pressure coefficients are different,the former is close to the active earth pressure coefficient,the latter is close to the coefficient of earth pressure at rest. 2)In the early stage of filling,the pore pressure of the bottom of geotextile tube is the largest,and the closer the boundary is,the faster it dissipates.In addition,the pore pressure of the center is always the largest,the upper is secondary,while the bottom is the smallest. 3)In the filling period the height of geotextile tubes is closely related to the central pore pressure.

Abstract:Aiming at the problem of sea level rising caused by global warming affects the hydrological characteristics of the estuaries in recent years,we study the impact of sea level rising on the flood and ebb duration difference of the Yangtze River estuary.We apply a two-dimensional mathematical tidal current model to simulate the effect of 100 cm sea level rising on the flood and ebb duration difference of the Yangtze River estuary when the runoff conditions of Datong in the upper reach are flood season,dry season and annual average runoff.The results show that sea level rising reduces the flood and ebb duration difference in the upper and middle reaches of the north branch,the south branch,the north channel and the south channel of the Yangtze River estuary,and has little effect in the last part of the north branch,the north passage and south passage near the offshore area.Sea level rising increases the flood tidal momentum of the estuaries,which reduces the flood and ebb duration difference of the Yangtze River estuary.Therefore,its impact on saltwater intrusion and sediment transport in the Yangtze River estuary must be taken seriously.

Abstract:Aiming at the problem of safety evaluation caused by structural damage of high-piled wharf,the safety evaluation indicators of the high-pile wharf structure are divided into the horizontal displacement of the macroscopic level,the top angle of the pile top and the pile strain based on the microscopic level.Based on the engineering practice,the finite element analysis model of the high-pile wharf structure is established and compared with the measured dynamic characteristics data.Combined with the finite element model and probability method,the safety evaluation indicators and their sensitivity laws of high-piled wharf structure are studied.It is concluded that the macroscopic safety index is highly correlated with the structural parameters,strength parameters and soil parameters of the pile,while the microscopic safety index is only sensitive to the effective cross-section area and local strength of the pile.The research results can provide a basis for structural damage warning and state assessment of high-pile wharf.

Abstract:Reasonable intranet network structure and traffic organization are important guarantees for the efficiency of container terminal operations and energy conservation and emission reduction.We propose to simulate the production operation process of container terminal by using the container terminal production operation agents and micro-traffic simulation model,and to optimize the road planning scheme for container terminal based on the port service level and the daily carbon emission cost of trucks as indicators.The application shows that the proposed simulation model can effectively simulate the container terminal operation,and outputs the values of evaluation indicators under different road planning schemes and the optimal road planning scheme,which provides reference for the design and management of roads within container terminals.

Abstract:The global sea level trend is generally adopted to calculate wharf deck elevation in port engineering at home and abroad,and the local and temporal characteristics of sea level variations are neglected.We discuss the mechanism and characteristics of sea level,and point that sea level variations include seasonal variation,inter-annual variation,decadal variation and long-term trend.The influences of local and temporal characteristics of sea level should not be neglected in the determination of wharf elevation.The results show that in order to determine the wharf elevation,besides considering sea level trend,the necessary seasonal,inter-annual and decadal corrections should be carried out on the basis of the time length of water level data.

Abstract:Based on the construction examples of the Japanese LNG terminal,we study its construction characteristics including the terminal’s layout form,berth number,port collecting and distributing network,overall layout of the receiving terminal and tank number. The form of most LNG terminals in Japan is jetty with no more than 2 LNG berths.The capacity of LNG tanks is in direct proportion to the population and local gross domestic product. As for the LNG consumers’demand in Japan, the average capacity is 0.093 m3person and 34.2 m3billion yen in 2017,which may be referenced by China. The research result may serve as reference for the construction and operation of Chinese LNG terminals.

Abstract:Aiming at the fact that all-vertical-piled wharf is prone to rotation than ranking-piled-wharf under the action of lateral force,we analyze the calculation method of rotation stiffness of all-vertical-piled wharf,and obtain a formula which based on rotation stiffness is derived to calculate the distribution of lateral force on all-vertical-piled wharf.Combining with an engineering example,we calculate the rotation stiffness and lateral force distribution coefficient of the wharf by the proposed formula in three different conditions of the width and length ratio.The results show that the increase of the width and length ratio will increase the rotation stiffness of the wharf,and make the lateral force distribution coefficient on each bent more uniform.The results obtained by the proposed formula agree well with the results by FEM(finite element method).As the rotational stiffness of the wharf increases,the difference between the calculated value of the formula and the norm value increases,and the maximum difference of the maximum horizontal forces distribution coefficient is 22%.

Abstract:In recent years,the automated container terminal has gradually formed the typical container yard handling technology scheme：the whole container yard is vertical to the terminal,and each yard is equipped with two ARMGs (automated rail-mounted gantry crane)which are responsible for the handling of the shipside and landside operation respectively. However,in the terminal under the high ratio of water to water transshipment,the shipside operation volume is higher than the landside volume,so ARMG handling on the two sides are unbalanced,which affects the ship handling efficiency.Analyzing the inadaptability of the scheme in the high-ratio water to water transshipment terminal,and combing the existing solutions at home and abroad,we propose a new targeted plan.Based on the scheme comparison,we put forward the solution idea,which may serve as reference for the design of similar container terminals.

Abstract:In this paper,ANSYS is used to establish a three-dimensional model to study the influence of different working conditions on the bearing behavior of large span non-complete bent structure for high-pile wharf.The results show that the load of portal crane has great influence on the internal force of piles,and the uniform load mainly affects the internal force of the middle longitudinal beam and cross beam,while the load of portal crane is the key factor for the internal force of track beams；the axial force of the piles under the middle longitudinal beam is obviously larger than that of the piles under the track beam,while the pile bending moment increases gradually from the wharf front to the land side；the double straight piles under the track beam between the adjacent bents play a role of stress redistribution in the internal force of the track beam,so that the stress of each track beam is more uniform,which is conducive to the synergistic effect of each cross-track beam and the joint bearing effect.

Abstract:The construction of a 100，000-tons outfitting and large cargo transportation berth in a repair and shipbuilding base in Guangxi Beibu Gulf adopts the conventional wet method of harbor construction,and the project has a large investment,a large amount of underwater reef blasting,a long transportation distance and a great impact on the marine environment.In view of this problem,the dry construction scheme and the hydraulic structure scheme of the ultra-high unloading and equilibrium-weigh retaining wall wharf are proposed according to the wharf layout and topographic and geological conditions.According to the current code and similar structure earth pressure calculation method,a simplified calculation method of earth pressure and structure internal force of ultra-high unloading equilibrium-weigh retaining wall structure is put forward.The stability and the size of the structure section of the retaining wall meet the requirements of the code.At the same time,aiming at the particularity of geology and structure,the detailed structure and construction quality control measures are put forward.

Abstract:For the problem that the automatic storage yard layout of Khalifa port container terminal phase II in Abu Dhabi is limited by the small depth of land area,we make a comparative study of two kinds of layout option of automated storage yard.The parallel arrangement option has more storage capacity than the vertical option on the premise of the same layout at the terminal apron.Considering the capacity,level of automation,personnel investment,system commissioning period and handling equipment investment,the project is determined to adopt the parallel layout option of the automated storage yard.

Abstract:The uneven flow of side orifice outlet of the long-culvert filling and emptying system inside the lock wall is the main reason for the overall flow and the wave motion in the lock chamber.In order to study the hydraulic characteristics of the side branch orifice in the uniform arrangement,we analyze the influence of water delivery mode,water head and valve opening time on the outflow of the side branch orifice by CFD numerical simulation.The results show that with the increase of filling and emptying time,the flow rate of each branch orifice increases first and then decreases,and the relative difference of flow distribution between branch orifices also presents a similar trend.When the lock chamber is filling,the flow distribution between branch orifices gradually increases from upstream to downstream and then decreases slightly at the end,and the branch orifice with maximum flow rate is roughly located in the latter 13 of the outlet section.When the lock chamber is emptying,the flow distribution between branch orifices increases gradually from upstream to downstream.The filling and emptying time of lock chamber is proportional to the water head and the valve opening time,and the filling time is slightly shorter than the emptying time when all others are same.

Abstract:The Huangpu River is a long channel in tidal river.Compared with other similar channels,the Huangpu River also has the characteristics of concentrated port area,varied time of ship entrance and not berthing at the optimal time of tide.For the above problems,we research the relationship between import time and duration of tide by the method of multi-station water level combined calculation.Taking import time as the constraint condition,we calculate the corresponding time from voyage to each section(tidal time)according to the specific import time(tidal time).Combined with the mathematical relation between the time of rising and falling tide of a single station and the time of passing the station,we calculate the tide duration and the riding high tide level.Through the calculation of this method,under the condition of limited import time,the optimal tidal time and the corresponding riding high tide level required for vessels to dock at each port area can be obtained,and then the maintenance elevation of each section of the channel can be determined respectively.This method can make rational use of limited resources and reduce project investment.

Abstract:Considering the lack of evaluation index of large cross-regional waterway network connectivity of main and tributary waterways of the Yangtze River,by using the method of dividing major sections and selecting major indexes,we divided the Yangtze River main and tributary waterway network into 7 sections through field investigation,and evaluated the connectivity of the Yangtze River main and tributary waterway network by taking the density of equivalent grade of net-waterway and the degree of connectivity of net-waterway as the main evaluation indexes.It is found that the evaluation index can not only objectively and reasonably reflect the technical characteristics of large-scale waterway network,but also has some economic evaluation functions.It realizes the rapid evaluation of the connectivity of the waterway network in the main stream and tributaries of the Yangtze River,and effectively solves the selection of evaluation index for the connectivity of large-scale waterway network.It has certain applicability and generalization.

Abstract:In order to analyze the bed load movement characteristics in the confluence area under the Taoyuan junction,the fixed bed flow and sediment transport experiments were carried out by using the integral fixed bed physical model to observe the distribution of water flow elements and sand transport belts under different flow rates.It is found that the hydrodynamic conditions in the confluence area are complex and changeable with the different confluence ratio,however,the range of sediment deposition in the confluence area is always closely related to the distribution of the main flow area.The bed load sediment is transported along the main stream,and the sedimentation bodies are mostly found at the boundary line of the transport belt,the turning point of the streamline and the concave under the local back surface of the riverbed.In the middle and low water period,the sediment transport under the dam is short distance because the discharge flow velocity is large and the flow velocity decreases rapidly along the river.In the flood period,the sediment transport is long distance because the river velocity is large.

Abstract:The fluvial process of Damazhou waterway is mainly affected by inflow conditions and shoreline changes of crucial river beaches,and adverse channel changes occurred recently.The channel regulation project already implemented aiming at the above problem has achieved expected regulation results but there are still problems such as lagged regulation timing,the lack of key parts of the project,and the insufficiency of dynamic design adjustment.In the follow-up waterway regulation and maintenance work,a tracking observation and analysis mechanism should be established to accurately grasp the latest channel conditions timely,and numerical and physical modeling techniques should be adopted to predict subsequent changes and to implement timely or to adjust dynamically channel regulation engineering measures.

Abstract:Combined with a river regulation project,aiming at the problem of slope excavation stability when residents’ houses and underground pipelines exist on both sides of a narrow section of the river,we carry out the stress analysis of U-shaped concrete ditch+single-row pile supporting structure and the study of slope stability of channel excavation，and use the whole calculation mode and method of vertical elastic grade beam to calculate the internal force and displacement of u-shaped concrete structure and pile supporting structure respectively.The results show that the U-shaped concrete ditch+single-row pile supporting structure is safe and reliable.The maximal displacement is 29.03 mm,and meets that the requirement of the horizontal displacement should not be greater than 30 mm in the specification.The construction is convenient,economic rationality,which can provide reference for similar projects.

Abstract:Restricted by the existing structures of the first-line ship lock,bridges,sluice,water transfer pump station and banks,the general layout of second-line ship lock of Wannian navigation junction of Beijing-Hangzhou Canal is complex.The lock positions are compared in combination with the restrictions of existing buildings,navigation conditions,safety and operation of adjacent buildings,operation and management,coordination and aesthetics,construction conditions and investment,and the optimal lock position is determined.According to the actual situation of the design vessel type and the conditions of the approach channel of the first-line lock,innovative schemes such as flexible mooring area and common berthing pier are adopted in the layout of the approach channel.It may serve as reference for the layout of multi-line lock in the concentrated area of buildings.

Abstract:Aiming at the problem of sediment accumulation in Huanghuacheng reach,which is a key sedimentary channel in the backwater area since the impoundment of the Three Gorges Reservoir,and based on the prototype observation data since the impoundment of the Three Gorges Reservoir,we analyze the water level change,sediment erosion and deposition characteristics,typical section erosion and siltation changes and isobath changes of the Huanghuacheng waterway,and predict the channel conditions and evolution trends of the channel.The results show that there is a cumulative siltation of fine sand in the Huanghuacheng waterway,and the main siltation site is relatively fixed;before 2012,the deposition rate,thickness and range were relatively large;after 2012,with the slowing down of the trend of sediment reduction from the upstream,the sedimentation rate of the Huanghuacheng waterway decreases.

Abstract:In view of the shore-to-ship power supply under the large water level difference condition in the Three Gorges reservoir area,a new shore-to-ship power supply system has been designed based on pontoon which can adapt to water level change.The facility adapts to different water levels by floating the pontoon up and down in the guide frame and adapts to the power supply of the ship at different free board heights through the two-story structure.The radar water level gauge is used to obtain the water level information,which is transmitted to the frequency conversion controller of the cable reel.Through the logic edit of the control system,the accurate retracting and releasing of the cable can be realized when the water level changes.Through the analysis of the existing technology,the feasibility and scientific of this system are proved,which provide the theoretical support for engineering design.

Abstract:In view of the unfavorable evaluation system of inland AIS service and ship complicated testing process,we propose a novel evaluation system from three different angles,i.e.,a single ship,a single base station and a navigation segment,based on which,we design an evaluation platform on the basis of the Yangtze River electronic channel chart to realize calculation of the evaluation indices and display of historical AIS data through multi-condition data query and data processing.Furthermore,a case study of AIS service evaluation is presented for the Yueyang reach,the Yangtze River.The results indicate that the loss rate of a single ship is quite different(\[6.73%,62.43%\]);the coverage areas of AIS base stations are overlapped with each other,resulting in that the loss rate of a single base station is about 45%;the overall loss rate and error rates are 16.63% and 1.57% respectively.The analysis results show that the AIS service performance could be effectively evaluated and the results could be visually analyzed.The study provides a useful tool for enhancing the reliability of inland AIS data,so as to ensure the navigation safety of inland ships.

Abstract:The conventional waterway network coding system is mainly based on the digital coding which describes the topological relation of waterway network,but the basic information content of waterway itself is less.This method is easy to computer storage,but not intuitive.In order to solve this problem,different types of waterway network codes are summarized by classification method,and a hybrid texture-number coding system is proposed.This system encodes the waterway network by combining words and numbers,which has the characteristics of high identification,convenience,high efficiency and strong applicability,and effectively solves the problem that the plane position relation and basic waterway information cannot be integrated in the process of waterway network coding.

Abstract:The effect of foundation reinforcement is closely related to the change of water content in soil during vacuum preloading.The traditional test method of the water content is model test in the laboratory.This paper introduces the neutron soil moisture meter into the field test of water content during vacuum preloading construction.The instrument calibration is carried out through the indoor test for field borehole soil sampling,and then the water content of soil during vacuum preloading is studied.Based on the laboratory test data of oven drying method and the neutron soil moisture meter test data before and after foundation reinforcement,the test precision of the neutron moisture soil meter is studied.The variation law of soil water content with vacuum preloading time at different depths is obtained,and the influence mechanism of vacuum load on soil water content is analyzed.The test method is simple and convenient,and the result accuracy is reliable.

Abstract:To make vibratory hammer selection for cellular steel sheet pile structure,the pile’s structure feature and sink resistance are analyzed,and existing dynamic skin resistance calculation methods for steel sheet pile are summarized.The cellular steel sheet pile sub-project of Hong-Kong-Zhuhai-Macao Bridge artificial island shows that,the vibration subsidence empirical method of cellular steel sheet pile structure abroad can meet the engineering requirements.Deflection deformation will occur inevitably when the cellular steel sheet pile is sinking.As a result,friction is generated between lock mouths of piles and the difficulty of the pile vibration sinking to the design elevation will greatly increase.Therefore,in addition to ensuring a certain rich coefficient,necessary construction measures must be adopted to control the affection of pile incline and deformation,to decrease the friction resistance and ensure the pile’s sinking to the design elevation.

Abstract:Aiming at the problems of axial compression performance,distribution law and design method of steel sheath and reinforced concrete(RCFST)structure,this paper takes the pile foundation of Chongqing Orchard Harbor Phase II as the prototype,the steel sheath thickness,reinforcement ratio and stirrup ratio as variables to carry out axial compressive test of RCFST short columns with slenderness ratio of 41.Considering the double restraint of steel barrel and stirrups on core concrete,the stress mechanism,stress-strain law and internal force distribution law of RCFST structure are studied by peeling analysis method,and the axial compression bearing capacity formula of RCFST short columns is derived and verified.In this paper,based on the results of the test and analysis,combined with the relevant specifications,the design method of reasonable diameter-thickness ratio of RCFST structure is given.The conclusion is that RCFST structure under axial compressive load is in the state of longitudinal pressure double stress,and its peak stress is less than the yield stress of steel sheath;the calculation result of axial compressive bearing capacity based on“unified theory”is closer to the laboratory physical model test value of RCFST short columns.

Abstract:The construction of pile foundation is the key to the construction of high pile supported dolphin structure,especially the construction of bored pile under complicated geological conditions in unshielded sea area due to many influencing factors and high technical difficulty.Based on the actual construction situation of bored pile for wharf approach bridge of a power plant in Pakistan,the construction conditions and key construction techniques are analyzed.The analysis results show that:for bored pile construction without overburden geology,steel casing construction is suggested to adopt the construction technology of combination of drilling and re-drilling;in order to ensure the perpendicularity of pile foundation,the corresponding piling guide frame should be designed according to the specific pile foundation conditions;in the process of underwater bored pile construction,if abnormal questions occur,construction should be suspended immediately and specific solutions needed to be put forward before continuing construction.

Abstract:The sea dikes is often constructed on silty soft ground and faces complicated environmental conditions such as tidal current and bad weather,and it is difficult to determine the deformation control standard of the sea dike project.Based on the measured data of the large sandbag embankment in Hengsha Island,we study the deformation control standard of the embankment from three indices,i.e.,the settlement rate,horizontal displacement rate,and ratio of settlement rate in the channel to horizontal displacement rate at the slope foot.The results show that the boundary effect is obvious during the surcharge period of the embankment,and it is limited to take the settlement rate as the main criterion of the stability of the large sandbag embankment.Since the horizontal displacement rate at the shallow strata is possibly beyond the standard value due to the compaction effect,it shall not be used to control the initial construction of embankment.The validity of the critical state line based on the ratio of the settlement rate in the channel to the horizontal displacement rate at the slope foot to control the stability of the large sandbag embankment is verified,and corresponding suggestions are put forward.

Abstract:The selection of wharf punch bored pile foundation types is studied in condition of thick granular strongly weathered granite with thin covering layer.By the calculation of project example,the batter punch bored pile plan and vertical punch bored pile plan are compared.Comparing with the vertical punch bored pile,the batter punch bored pile plan is characterized by high horizontal bearing capacity,low bending moment and low engineering cost.According to the offset-axes and hole-collapse in the construction process of the batter punch bored pile,we summarize the prevention measures including adding the guide-hole,guide apparatus,pre-buried duct and driving the secondary steel casing,which can be used as reference for similar projects.

Abstract:The sinking process of HDPE pipelines significantly affects the efficiency and success rate of underwater connection of HDPE pipelines,which is a very important link in HDPE pipelines offshore installation.We systematically study the watering sinking process of large diameter and over-length HDPE pipelines by the combination of theoretical analysis and practical investigation,first propose the method of using airbag and sacrificial rope to control the watering sinking of pipelines,and obtain the method and principle of determining the number of airbags.Furthermore,we propose the watering sinking process of large diameter and over-length HDPE pipelines under the condition of changeable water depth.The process has been applied to water intake and drainage engineering of large diameter and over-length HDPE pipelines installation for the integrated gasification combined cycle project (JIGCC) in Jazan,which can provide reference for similar projects in the future.

Abstract:When the underwater concrete is poured by tremie method,the exposed reinforcement accident is often caused due to the inadequate accuracy control of the lifting tremie of the crane,which affects the safety and economy of the project.The theory of trench stability during underwater concrete perfusion is proposed to improve the construction quality of underwater concrete perfusion and reduce necking accidents.Based on a multi-purpose berth project in Jingtang port area,a new type of underwater concrete pouring equipment is developed,and design concept,structure and operation process of the equipment are summarized.The actual project shows that the effect of diaphragm wall surface after excavation is better by using this equipment to pour underwater concrete.The relevant technology can provide reference for similar projects.

Abstract:Aiming at the problem of large caisson volume,overweight weight and precast caisson pedestal in an ore wharf,the traditional method of using air bag to jack up at one time can not be adopted.By adopting a new method of jacking up at the same time,the problem of insufficient air bag jacking and inability to jack up large and overweight caisson is solved.The results show that by adjusting the aeration pressure of the air bag at the bottom of the caisson,alternate jacking up of the caisson before and after can be achieved.By this method,the air bag need not to be in the state of super-high pressure,and it can meet the filling pressure requirements of the air bag relatively quickly.It can be used as reference for the large-scale caisson construction.