Abstract:The structure of the anchorless steel sheet pile combined with the DCM(Deep Cement Mixing pile)block was used for the construction of small docks.The combined structure took full advantages of the high shear strength of steel sheet pile and the high mass of DCM block,and achieved the purpose of reducing the amount of construction excavation，shortening the construction period,minimizing distractions to the surrounding, and rapidly forming the dock under the silt geological conditions.The combined structure has been successfully used in the design and construction of the bridge pre-casting pier of the CB03 section for the national key project “Hong Kong-Zhuhai-Macao Bridge”,which has proved its applicability and advantages.The combined structure provides a technical reference for the construction of small wharf and the design and selection of supporting structure under the soft soil and even silt geological conditions.At the same time,the design and calculation methods such as the conversion of soil calculation index,the overall and local checking of the structure also have certain popularization value.

Abstract:The service life and cost of high-pile wharf in sea water depend on the design and construction of anti-corrosion for steel pipe piles and reinforced concrete structures.Unsuitable anti-corrosion for the wharf will cause destruction to the structures.Through the application of sacrificial anode method cathodic protection system for berth No.69 of industrial port in Yanbu,Kingdom of Saudi Arabia,we analyze the design principle for the cathodic protection system of high-pile wharf,and compare the applicability,parameters,and construction method of three different anti-corrosion products,including aluminum base blocks,zinc net,and zinc slab.The cathodic protection system is optimized by research,comparison and selection of methods in the process of implementation.The optimized cathodic protection system is safe and reliable,installation convenience,easy maintenance,and controllable cost,which obtain the excellent results.

Abstract:Taking a high-piled wharf as an example,aiming at the problems of low efficiency of installation and construction of beam and slab on the sea and high construction cost of concrete pouring by mixing vessel on the sea under harsh sea conditions,technological innovation was carried out,such as bridge erecting machine to install prefabricated beam slab,pump truck to pour concrete on board,prefabricated beam using marble bottom tire and other new technologies and methods,which well avoided the influence of bad sea conditions on the installation of prefabricated beam slab and controlled the construction cost.

Abstract:Generally,the system equipment of port has a large size and great mass,and crane rails with a large cross-sectional area are often used as walking rails.According to the characteristics of the port system equipment and the conditions of the project construction site,combining with the structure of the dock and yard,and with reference of the seamless connection technology of the light rail,we analyze the material composition of the rail and the internal organization changes in the welding process,and recommend a connection method and process to ensure the safety of equipment use and the comfort of operators,stable connection,easy maintenance,simple operation and satisfy the requirements of the rail installation site of port system equipment,which is conducive to achieving the construction period target and can be widely popularized and applied to the rail connection of heavy locomotives or lifting equipment such as mines,ports,power plants,docks and yards.

Abstract:Wave is one of the most important hydrodynamic factors affecting coastal breakwaters.The long-period wave can penetrate the wave-permeable breakwaters,which has great impact on the hydrodynamic environment inside the breakwater,and brings some difficulties to the demolition and new construction of the breakwater and other hydraulic structures.In view of the breakwater project at the entrance of a canal in west Africa,the construction characteristics and difficulties of each item of breakwater project are analyzed according to the problems such as the long period wave influence environment and the difficulty of water construction,and the corresponding solutions are formulated,finally the reconstruction of breakwater is completed successfully.

Abstract:The main concrete structure of the high-pile beam slab wharf is generally composed of pile foundation,beam(cast-in-place),longitudinal beam system(cast-in-place or pre-fabricated installation),panel(cast-in-place or pre-fabricated installation),surface layer(cast-in-place),etc.The upper load of the wharf is transmitted from the beam to the pile foundation.Therefore,the quality requirement to the beam is very high.The cast-in-place beam is generally located in the water level fluctuation zone,which is seriously affected by the tide.The construction on site is difficult and the construction quality is uncontrollable.Taking the SGPJB Jawa 7 Power Plant project in Indonesia as an example,this paper introduces the construction of the lower beam of the high-pile wharf under the suspended bottom mold method,which effectively reduces the impact of the tide on the beam construction.The site construction is convenient and the construction quality of the beam is guaranteed.Meanwhile,good economic and social benefits are achieved.

Abstract:Aiming at the problems of large beam mass,large span and poor sea conditions encountered in the installation and construction of T type girder for approach bridge of the wharf project of the second phase of Suizhong power plant,the methods of ship and machine positioning,temporary strengthening and accurate positioning in the process of T beam transportation and installation are proposed.T-beam is lifted by special hoisting frame to ensure that both ends of T-beam are under vertical force.Various protective measures are taken during installation.In the process of transportation and installation,temporary reinforcement and accurate positioning are adopted.T-beam installation process is relatively smooth,the feasibility of construction technology has been verified.

Abstract:Aiming at the problem that there is no unified standard for the calculation of lifting caisson floating stability,the force of the lifting caisson is analyzed in detail through moment balance analysis and floating center movement calculation,and the theoretical derivation is made for the calculation of lifting caisson floating stability.Calculation formula for the equivalent metacentric height in small dip angle is obtained.The calculation table of lifting caisson is designed and the relation diagram of lifting force,draft and metacentric height is drawn.The economic and reasonable distribution method of ballast and lifting force is given using chart analys method,combined floating distance and channel depth limitation.Finally,it can provide reference for the floating transportation engineering of lifting caisson.

Abstract:In the construction of traditional caisson gravity wharf, the fender is located on the breast wall,which is easy to install and simple to construct;the rear track beam is situated on the caisson and there is no differential settlement between the front and back track beams;flash butt welding is the main method for track connection,with low construction efficiency and low quality welded by welders;horizontal influence is greater;surface crack is a common quality defect in wharf construction,which directly affects the apparent quality of wharf.Taking the second phase of the container terminal of the second harbor basin of Jinzhou Port as an example,we optimize and adjust the construction technology of fender,caisson backfill prism (back track beam foundation),rail connection and breast wall crack prevention for low elevation gravity wharf,and have obtained the good effect.

Abstract:Cast-in-place concrete is partly below the surface of the water in the Dai estuary fishing port west bank line repair and reconstruction project,the installation of underwater formwork and pouring concrete underwater are used in construction.We propose a cantilever rigid underwater template,and introduce the characteristics of this underwater template from several aspects such as the design idea,the construction technology and method of the field installation.The results show that the cantilever rigid underwater template can transform underwater problems into land solutions,meet the overall stability of underwater template under the action of concrete side pressure,and ensure the installation accuracy requirement of underwater template at a low cost.This technology has good application effect,which can provide references for the similar projects.

Abstract:In traditional waterway engineering,the main method of foundation treatment in dredger filling area is vacuum preloading or surcharge preloading,and the main method of foundation treatment in non-dredger filling area is dynamic compaction.Taking the second phase of the container terminal project of the second harbor basin of Jinzhou Port as an example,we divide the site area according to different geological conditions,and carry out the comprehensive treatment by choosing different processes.According to the treatment results of surcharge preloading,dynamic compaction (dynamic compaction replacement) and vibroflotation,we verify the applicable conditions of three soft foundation treatment technologies,which can provide reference for similar engineering construction.

Abstract:The high-pile wharf built on weathered rock often encounters large changes in local quality,fluctuations in rock formation and with many cracks,or geological and design inconsistency.If the rock strength is high,the steel pipe pile is prone to deformation during installation,resulting in embedding.The hammer is generated during punching of the rock-embedding pile,and the hole cannot be formed normally,which affects the construction of the pile foundation.Taking the Cambodia Union Port as an example,We explain how to avoid the deformation of steel pipe piles during construction of rock-socketed piles,introduce the method of underwater cutting and plugging of the cut parts of the steel pipe pile after deformation,which ensures the normal construction of the rock-socketed piles.The completed rock-socketed piles are all tested as Class I piles,which proves the practicability and operability of this method.

Abstract:Differential settlement of track beams before and after gravity quay has long been a difficult problem to harbor construct.The front track beams act on caissons,the settlement is not large,and the settlement process can be basically completed during construction period.The rear track beams generally act on prisms,and tamping measures are generally not adopted considering the safety of caisson.The backfill itself is compacted,resulting in a significantly large settlement during the service period,which affects the operation of the equipment.If the cast-in-place pile foundation is adopted,because the cast-in-place pile needs to penetrate prism with block stone or karst stone,which brings great difficulty to the construction of cast-in-place pile.Taking Caofeidian Coal Terminal of Guotou as an application example,this paper adopts prism multi-layer dynamic consolidation technology on land and underwater,which effectively alleviates the differential settlement between front and rear rails,obtains good economic and social benefits,and provides a reference basis for the design and construction of similar engineering structures.

Abstract:In order to overcome the harsh natural conditions and speed up the construction of offshore reefs,it is necessary to find a new rapid land formation technology. In order to reduce site operation and rapid construction,this paper studies the feasibility and adaptability of rapid land formation technology in shallow draft caisson structures from the aspects of caisson structure,functional requirements and rapid land formation implementation method.By optimizing the caisson structure and analyzing the field conditions,the light caisson which can meet the requirements of drag-and-carry draft and the use of function is obtained,and the method of non-leveling installation of the caisson on the base bed is developed.The feasibility of the key technology is verified through the light concrete caisson precast and the reverse top lift leveling test,which provides data support for the later application of the technology.

Abstract:To ensure the overall stability of steel cylinders and auxiliary grids after vibration and sinking of the artificial island wall steel cylinders and auxiliary grids of the Hong Kong-Zhuhai-Macao Bridge,we adopt the fixed-point,relay and layered backfilling schemes for the backfilling construction of steel cylinders and auxiliary grids,which can better control the structural safety of the steel cylinder enclosure structure during backfilling construction and prevent the appearance of adverse conditions.Before the enclosure of the artificial island,underwater backfilling is carried out by means of direct dump and pumping.After the enclosure of the artificial island,the land area of the east and west artificial islands of the Hong Kong-Zhuhai-Macao Bridge is quickly formed by means of the scheme of dump and backhaul on the road,which accumulates experience for the quick formation of the offshore artificial island.

Abstract:During excavation of ultra-deep foundation pit off the west artificial island of the Hong Kong-Zhuhai-Macao Bridge,the piping of the foundation pit formed by the penetration of the pre-embedded pore water pressure monitoring instrument through the confined water layer was blocked by adopting the methods of high pressure jet grouting pile reinforcement,barite powder grouting,double liquid grouting and bag grouting.In this way,the problems of plugging at the initial stage of the piping point and the period when the piping path is obvious,were solved respectively.Especially,under the premise of no risk of collapse at the piping point,the plugging technology of grouting expansion along the piping path into the bottom of confined aquifer to achieve rapid water stop,skillfully solves the problem of piping plugging under high head difference.

Abstract:At present,the technical indexes of artificial sand are all carried out according to the standards of the Ministry of Construction.However,the allowable content of artificial sand powder in the standard is relatively large,and no specific provisions are made for artificial sand in anti-freezing concrete.We prepare the anti-freezing concrete by adding single fly ash or double fly ash and mineral powder with the different mixing proportions of river sand and artificial sand,and analyze the effects of various factors on the mixture properties,strength and durability of anti-freezing concrete.Based on an engineering example,the results show that the gradation of single artificial sand is poor,and it is advisable to mix it with river sand to effectively control the content of stone powder.Adding appropriate amount of admixtures can improve the performance of artificial sand concrete,and increase the mechanical property and durability of concrete.

Abstract:The mix proportion of steel-shell submerged tunnel using self-compacting concrete adopts C50 upper flow regime,self-compacting and shrinkage compensating concrete.The tests on the performance,strength,limited expansion rate and durability of concrete are carried out by preparing the self-compacting concrete with different water-cement ratio,different amount of cementious material and different amount of expansive agent,and the experimental data are analyzed and compared.The results indicate that the concrete prepared with 530 kgm3cementious material,20% fly ash,15% slag powder and 8%～12%expansive agent,0.31～0.35 water gel and 48%～50%sand ratio has good fluidity,cohesiveness and segregation resistance,and its strength and durability meet the design requirements.

Abstract:Combining with the construction of pre-tensioning pre-stressed hollow square piles in the Tadee liquid chemical terminal project of Huanghua port,we analyze the control key points of the pre-stressed high performance concrete quality from some aspects,such as the quality of raw materials entering the field,concrete air content,and measurement deviation control of mixing station etc.We also analyze the reasons of a series of quality problems such as large slump loss,large thickness of floating slurry,large protective layer of steel and crack on pile surface in the pre-tensioning pre-stressed square pile concrete construction process,and propose the effective concrete construction quality control measures to ensure the physical quality of the subsequent pre-stressed concrete square piles.

Abstract:The molecular structure and mechanism of polycarboxylate superplasticizer and naphthalene superplasticizer are different.We add polycarboxylate superplasticizer and naphthalene superplasticizer respectively into the anti-freezing concrete with the air entraining agent of rosin thermal polymer,test the properties of fresh concrete,compressive strength and freezing resistance,observe the pore characteristics and microstructure of hardened concrete,and analyze and compare the effects of polycarboxylate superplasticizer and naphthalene superplasticizer on various properties of concrete.The results show that polycarboxylic superplasticizer has many advantages over naphthalene superplasticizer.It can be used to prepare concrete with low water-binder ratio under the condition of low dosage,and can be applied to anti-freezing concrete.

Abstract:The sea area project of the supporting terminal project of the second phase of Suizhong Power Plant is located in the uncovered waters of the Bohai Bay offshore.It is affected by winds and waves all year round,and the winter temperature is low and the durability requirement of concrete is extremely high.The concrete T-beam of the approach bridge is a post-tensioned pre-stressed structure.According to the comprehensive performance requirements,we select high-quality raw materials of concrete,analyze the microstructure of concrete by scanning electron microscopy,compare the influence of different admixtures and admixtures on the performance of hardened concrete,and apply the absolute volume method to design mixing proportion of pre-stressed and high performance anti-freezing concrete.Through the engineering verification,we finally obtain the mixing proportion of the concrete which meets the construction and design requirements.

Abstract:The main structure of the bank wall of the west artificial island for the passage from Shenzhen to Zhongshan consists of 57 large diameter(28 m)steel cylinders and auxiliary lattices to form a water-stopping cofferdam.The cost of steel cylinder is high.The corrosion resistance of steel cylinder is poor,and the later maintenance cost is high in sea water environment.We design a cylinder scheme of steel and reinforced concrete composite structure,which replaces the steel cylinder.We compare the reliability,feasibility and economy of this structure with steel cylinder.The results show that the cylinder scheme of steel and reinforced concrete composite structure is generally feasible,high reliability and low cost,which can provide certain references for similar projects.

Abstract:Temporary cofferdam is needed to stop water and dewatering during the construction of the outlet cofferdam in the D section of the second phase extension project of Guangxi Qinzhou power plant,so as to obtain the dry construction conditions.After scheme comparison and optimization,scientific calculation and reasonable demonstration,the combined structure of filling sand bag,jet grouting piles,steel sheet pile,cast-in-place pile,brick water-stop wall,water-stop ring beam and water-stop clay wall is adopted.Based on the characteristics of different water-stopping structures,the structures of cofferdams in water area and land area under different environmental conditions are optimized and designed reasonably,which effectively solved the construction difficulties such as small local space and large head difference,and achieved good engineering results.This method has certain reference value in the design optimization and selection of similar projects.

Abstract:Silt easy occurs after foundation trench excavation,which affects the installation quality of the recast unit.Flow silt exists on the surface of the original mud surface near the west artificial island of Shenzhen—Zhongshan Bridge,so temporary silt-retaining structures should be installed on both sides of the sunken pipeline foundation trench.According to the analysis and comparison of the fabricated silt-retaining structure scheme of cylinder+fender+flexible inserted plate and the steel sheet pile,we know that the fabricated silt-retaining structure scheme has obvious advantages in construction difficulty and construction period,and give an introduction of the structure design and construction process of the fabricated mud retaining structure scheme,which is characterized by good stability,simple technological process and high assembling degree,and meets the requirements of the mud retaining function of the sink base. It may serve as reference for the construction projects of mud retaining of deepwater sunken pipeline foundation trench.

Abstract:The underground structure construction of car-dumper shed is long and complicated.It will be some problems by layered and zoned construction with post-casting zone,such as dense steel in the zone,difficult for worker entering and ensuring construction quality etc.We replace part of the post-casting zone with the expansion reinforcing zone,and pour the concrete as the original construction sections at the same time.The technology is combining the expansion reinforcing zone and the post-casting zone as a whole.The concrete out the zone is compensating shrinkage,and the concrete in the expansion reinforcing zone and post-casting zone is filling compensation shrinkage concrete.It can solve the problem about anti-crack and anti-leakage of concrete,reduce the construction time,and bring better economy benefit.

Abstract:During excavation of the foundation pit,due to the excessive lateral soil pressure,foundation pit deformation easily occurs,which leads to the instability of the support system.Therefore,selecting a reasonable way to reduce the lateral earth pressure is effective for improving the stability of the foundation pit support.For the soil with high consolidation and low water content in Hengqin area of Zhuhai,LXK method pile is used to support the foundation pit.After the soil outside the foundation pit is treated by the LXK method pile,the consolidation degree of the soil body improves obviously,and the lateral earth pressure decreases.Meanwhile,the sidewall of the foundation pit and the rear soil form a stable whole,which is not easily disturbed by external changes,so the difficulty of foundation pit support in soft soil is solved effectively.

Abstract:The water stopping effect is the key point of the project on the construction of deep foundation pit in highly permeable stratum,and the water-stopping method has a great impact on the safety,progress and cost of the project.Based on the study & comparison of foundation pit’s water-stopping construction methods of the foundation pit of the coal-containing sewage treatment pond in SG-03 section of Jinzhou Port coal terminal phase I project,we know that the bored interlocking pile has obvious advantage in construction progress,quality control,economy,etc.on the construction of the deep foundation pit in coastal highly permeable stratum such as bored interlocking pile,high-pressure jet grouting wall,plastic concrete cutoff wall and clay core wall,etc.Based on the discussion of the adaptability and construction control points of the bored interlocking pile,we point out the problems occur possibly in actual operation and propose treatment measures.The result shows that the bored interlocking pile achieves a perfect effect on the construction of deep foundation pit in highly permeable stratum.

Abstract:In soft foundation treatment by blasting silt extrusion,there are many external factors affecting its implementation effect and the external environments of different construction areas are quite different,so it is difficult to apply the previous construction experience directly.For achieving the best effect of blasting silt squeezing,combining with the reclamation project of Dalian Airborne Industrial Park,we study the influence of external factors such as working environment,stone filling and charge distribution on the effect of blasting silt squeezing by means of field comparative test.The test results show that the effect of silt extrusion is better when using better graded and smaller-sized stones in blasting construction at high tide level.At the same time,the effect of silt extrusion by blasting can be fully guaranteed by the method of pressing charge distribution,which is easier to ensure the quality of charge distribution than that by vibration charge distribution.By formulating a reasonable construction plan,the blasting silt squeezing construction is successfully completed,and the quality of the cofferdam meets the design requirements.