Gravity-caisson wharves have been widely constructed in coastal and island regions, which are threaten by potential underwater explosions. This work aims to study the dynamic behaviors and propose a damage evaluation ...Gravity-caisson wharves have been widely constructed in coastal and island regions, which are threaten by potential underwater explosions. This work aims to study the dynamic behaviors and propose a damage evaluation approach of caisson wharf against underwater explosion. Firstly, based on both the underwater explosion loading test and underwater explosion test on the reduced-scale caisson specimen, a high-fidelity finite element analysis approach for numerically reproduce the dynamic behaviors of prototype caisson wharves against underwater explosions was proposed and verified. Secondly, the underwater explosion loadings and dynamic behaviors of prototype caisson wharf (14.9 m×8.1 m×10.95 m) against sequential blast wave and bubble pulsation of typical torpedo with a charge weight of 200 kg were studied. The influences of the seabed and cabin infill materials, as well as the explosion standoff distances of 3.4–10.2 m and depths of burst between 1/4 and 3/4 of water depth, on the blast resistance of caisson wharf were further examined through deflection distributions of exterior wall, damage evolution, and overall displacement of caisson wharf. Finally, a performance evaluation approach for prototype caisson wharves against underwater explosions was proposed by comprehensively considering the bearing, storage, and berthing capabilities. The corresponding protective measures and design recommendations were further provided. It indicates that: (i) under the explosion of a typical torpedo, the damage modes of prototype caisson wharf mainly involve the overall vibration, spalling and cracking of the exterior wall, collapse of the upper operating platform and cracking of the top plate;(ii) the blast wave and cavitation zone generated between the bubble and the exterior wall are the two primary causes of damage to caisson wharf;(iii) compared to the saturated calcareous sand seabed, the assumption of rigid seabed underestimates the spalling on the exterior wall, which is not recommended for scenarios where cavitation zones may generate;(iv) rock rubble is the most effective infill material in improving the blast resistance of caisson wharf among four types of infill configurations, i.e., fully filled and half-filled saturated calcareous sand, rock rubble and pure water;(v) the standoff distance of 10.2 m is regarded as a secure protective range in the scenarios discussed currently. As the standoff distance decreases and the depth of burst increases, the spalling of the exterior wall induced by the cavitation intensifies, posing a great threat to the functionality of caisson wharf.展开更多
Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not w...Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not without consequences for the countries concerned. Benin, a country in the Gulf of Guinea, is no exception to this phenomenon because, due to its maritime history, it has a heritage of port structures. These structures, built on its coastline, cause a wide variety of environmental problems such as silting and erosion on either side of them. The general objective of this article is to contribute to the proper functionality of port facilities while minimizing environmental problems that may arise. It aims to provide managers with a tool allowing them to fully understand the state of their assets in order to rationalize maintenance actions. In order to achieve this objective, an assessment of the state of the structure, and then a structural diagnosis are necessary and recommendations can be established to restore the level of service of the latter. As a result, two examples were presented: the wharf of the Sèmè-Podji pipeline project and the maritime piles project of the Wasco de Gama bridge (control project), and recommendations adapted to this objective were established. The comparative analysis of the two examples, both maritime works, revealed an under-sizing at the level of the spans of the wharf bridge of the Sèmè-Podji pipeline project (spans of 7 m in length), while these spans vary on average by 45 m to 62 m for the Wasco da Gama bridge. Bringing the piles closer together at the Sèmè-Podji wharf reduces the energy of the current which promotes the accumulation of sediment. The structure no longer experiences a flow capable of setting in motion the sands accumulated since at least 2022. This element appears to be a fundamental characteristic explaining the erosion observed to the east of the structure.展开更多
This paper presents a new type of steel pipe pile wharf connection node.The steel pipe and concrete are connected by ultra-high performance concrete(UHPC)grouting to improve the bonding performance between the concret...This paper presents a new type of steel pipe pile wharf connection node.The steel pipe and concrete are connected by ultra-high performance concrete(UHPC)grouting to improve the bonding performance between the concrete and steel pipe and enhance the mechanical performance of the specimen under earthquake action.A bond test between the steel tube and the concrete was carried out.Considering the interaction between materials,the proposed concrete constitutive model was proposed.The finite element analysis method was used to simulate the structural response of the UHPC grouting connection concrete-filled steel tube(UCFST)beam-pile joint and the normal strength concretefilled steel tube(NCFST)beam-pile joint under earthquake action.The results indicate that the bond performance between the UHPC and the steel tube is stronger.The UCFST specimen has a relatively high bearing capacity and stiffness.When the ratio of the UHPC grouting layer to the component diameter is 0.5,the bearing capacity is the highest.When the ratio is 0.37,the ductility is the highest.When the ratio is 0.25,it combines the advantages of the two situations mentioned above.UCFST specimens have better energy dissipation capacity and damage,which can effectively improve the seismic performance of components.展开更多
This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-s...This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-source software Open FOAM~?, a two-dimensional viscous-flow numerical wave flume was developed to simulate the fluid resonant motions induced by transient focused wave groups with different spectral peak periods and wave amplitudes. The results indicate that for all the incident focused wave amplitudes considered, the amplitudes of the free surface elevation in the gap, horizontal wave force and moment all exhibit a bimodal variation trend with increasing spectral peak period. The peak values of the above amplitude-period curve appear near the resonant period of the first and second harmonic components of the free surface elevation. However, the variation in the vertical wave force versus the spectral peak period presents different patterns. In addition, the first-to fourth-order harmonic components in the wave surface and forces are further examined via the four-phase combination method. The results show that the first-to secondorder harmonic components play a dominant role in the overall amplitude.展开更多
High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate l...High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate large tonnage vessels, wharves should be eorrstructed in deep water gradually. However, conventional high-pile and beam-slab structares are hard to meet the requirements of large deep-water wharf. According to arch＇ s stress characteristics, a new type of wharf with catenary arched longitudinal beams is presented in this paper. The new wharf structure can make full use of arch＇s overhead crossing and reinforced concrete compression resistance, improve the interval between transverse bents greatly, and decrease underwater construction quantity. Thus, the construction cost cab be reduced. Take the third phase project of the Yangshan Deep-water Port for example, comparative analysis on catenary arched longitudinal beams and conventional longitudinal beams has been made. The result shows that with the same wharf length and width, the same loads and same longitudinal beam moment, catenary arch structure can improve the interval between bents up to 28 m, decrease the nmnber of piles and underwater construction quantity.展开更多
All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static ...All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method （FEM） and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the ＇plastic hinge＇. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom （SDOF） system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions.展开更多
As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage detection methods are greatly limited in thei...As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage detection methods are greatly limited in their application to pile foundation in service. In the present study, a new method for pile foundation damage detection is developed based on the curve shape of the curvature mode difference(CMD) before and after damage. In the method, the influence at each node on the overall CMD curve shape is analyzed through a data deletion model, statistical characteristic indexes are established to reflect the difference between damaged and undamaged units, and structural damage is accurately detected. The effectiveness and robustness of the method are verified by a finite element model(FEM) of high-pile wharf under different damage conditions and different intensities of Gaussian white noise. The applicability of the method is then experimentally validated by a physical model of high-pile wharf. Both the FEM and the experimental results show that the method is capable of detecting pile foundation damage in noisy curvature mode and has strong application potential.展开更多
In the present study,the formula calculating ship impact forces on light wharf structures is presented when the elastic deformation of the hull and the pier structures as well as the nonlinear deformation of the fende...In the present study,the formula calculating ship impact forces on light wharf structures is presented when the elastic deformation of the hull and the pier structures as well as the nonlinear deformation of the fender are taken into account. The ship impact forces are statistically analyzed with the Monte-Carlo method according to the known probability distribution types of random variables.Based on the simulated results, the distribution of ship impact forces which is characterized by bimodal distribution can be expressed as the combining probability density function of beta distribution and normal distribution. The corresponding parameters of the probability density function can be estimated with the maximum likelihood method. The results show that ship impact forces on light wharf structures follow the distribution of type I extreme value.The mean coefficient and variation coefficient are 1.11 and 0.008 respectively during 50 years of design reference period.展开更多
There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly aff...There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications.展开更多
Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily dam...Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily damaged.Once the structure of high-pile wharf destroyed,it is bound to be a great threat to the safety of various facilities and personnel in the port.Given all of that,the multi-level comprehensive evaluation method based on the extension theory is proposed in this paper.Using this method to assess the safety of high-pile wharf structure,the reasonable advice on its maintenance and reinforcement can be given in time.What’s more,the method is simple and can give more objective result of the evaluation.展开更多
A bold innovation was carried out for the structural type of wharves in line with local conditions in Chiwan Port, in which a group of wharves with novel structures have been built in this port during the past ten years.
Earthquake investigations have shown that near-fault pulse-like(NF-P)ground motions have unique characteristics compared to near-fault non-pulse-like(NF-NP)and far-field(FF)ground motions.It is necessary to study the ...Earthquake investigations have shown that near-fault pulse-like(NF-P)ground motions have unique characteristics compared to near-fault non-pulse-like(NF-NP)and far-field(FF)ground motions.It is necessary to study the seismic response of pile-supported wharf(PSW)structures under NF-P ground motions.In this study,a three-dimensional finite element numerical model is created to simulate a PSW.By imparting three types of ground motion,the engineering demand parameters(EDPs)of PSW under NF-P ground motions were analyzed and compared,in which EDPs are the maximum displacement and bending moment of the piles.Twenty intensity measures(IMs)were selected to characterize the properties of ground motions.The correlation between IMs and EDPs was explored.The results show that the piles present larger displacement and bending moment under NF-P ground motions compared to NF-NP and FF ground motions.None of the IMs have a high correlation with EDPs under NF-P ground motions,and these IMs are more applicable to FF ground motions.The correlation coefficients between EDPs and IMs under three types of ground motion were obtained,which will provide a valuable reference for the seismic design of PSWs.展开更多
In the process of rapid development of urbanization and constant adjustment of urban space,urban characteristics are faced with many challenges.Taking Taiping Bay wharf area of Yantai City as an example,the paper sort...In the process of rapid development of urbanization and constant adjustment of urban space,urban characteristics are faced with many challenges.Taking Taiping Bay wharf area of Yantai City as an example,the paper sorts out the spatial construction problems from the aspects of historical development,urban texture and cultural characteristics by exploring the research process and methods of regional urban design,and put forward optimization strategies from the perspectives of urban structure optimization,street image design,industrial building transformation and cultural space establishment based on the characteristic resources of the area,thus providing experiences for future regional urban design.展开更多
Occupational health management of liquid chemical transport wharf is still in its infancy,to grasp the occupational health status of employees in the industry and improve the occupational health management level of em...Occupational health management of liquid chemical transport wharf is still in its infancy,to grasp the occupational health status of employees in the industry and improve the occupational health management level of employees,taking the liquid chemical transport wharf of an enterprise as the investigation object,according to the relevant domestic occupations.Hygiene standards,using the combination of on-site occupational hygiene survey and workplace occupational hazard factors detection,identify the occupational hazard factors of the wharf and detect the degree of hazard.The survey results show that the overall occupational health of the wharf is basically good,but the noise index is slightly exceeded.It is suggested to further improve the occupational health management level of the wharf by improving the protection technology and strengthening the administrative management.展开更多
This paper introduces the main construction types of inner fiver whar~ analyses the developing trend of the construction types of wharf in mountainous areas, point out that suspended vertical wharf is the main constru...This paper introduces the main construction types of inner fiver whar~ analyses the developing trend of the construction types of wharf in mountainous areas, point out that suspended vertical wharf is the main construction type for deep-water, huge water fluctuation river terminals. Opentype wharf on pilcs is also a new- type wharf structure in mountainous areas with great water fluctuation.展开更多
foundation settlement is one of the common problems in the construction and use of gravity wharf. Causes gravity type wharf foundation settlement reason is very complex. Based on the full understanding of the concept ...foundation settlement is one of the common problems in the construction and use of gravity wharf. Causes gravity type wharf foundation settlement reason is very complex. Based on the full understanding of the concept of gravity quay wall, this paper analyzes the reasons of the foundation settlement of gravity wharf. And Put forward the corresponding prevention and countermeasures.展开更多
Gravity wharfis a kind of wharf which is widely used. At the dock construction, usually meet various such as trench back silt, rear edge backfill, rail displacement settlement of a series of; control of these problems...Gravity wharfis a kind of wharf which is widely used. At the dock construction, usually meet various such as trench back silt, rear edge backfill, rail displacement settlement of a series of; control of these problems and solve for the construction quality of the pier is very heavy. Based on some experiences in the construction of wharf, this paper puts forward some methods to solve and control some of the above problems.展开更多
As the stiffness discontinuous of large diameter steel tube and concrete combined pile, the complicated stress state is caused by the combination of the pile foundation and the base rock, the steel casing and the bedr...As the stiffness discontinuous of large diameter steel tube and concrete combined pile, the complicated stress state is caused by the combination of the pile foundation and the base rock, the steel casing and the bedrock structure. It is needed to put forward a scientific basis to determine the pile foundation effective depth of embedded. For this purpose, the physical model and the numerical model of single pile with large diameter steel tube and reinforced concrete combined force are established. Through numerical simulation and contrast test of a large number of variable parameters, the various factors that affect the lateral bearing capacity of the embedded piles are discussed in detail, the mechanical properties of the foundation under the action of the steel tube and the pile foundation are obtained.展开更多
Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by AB...Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by ABAQUS sot＇cware to study the impact of cross section type, the pile spacing and soil properties on soil arching effect. We find that cross section type of the pile has a certain influence on soil stress distribution in front of the barrier piles by comparing circular cross section and rectangular cross section. We also find that clear distance between the barrier piles and cohesive force of the soil have a great influence on that impact. We can increase clear distance between the barrier piles appropriately to improve the efficiency of construction and reduce the proiect cost.展开更多
基金supported by National Natural Science Foundations of China(Grant No.52308522).
文摘Gravity-caisson wharves have been widely constructed in coastal and island regions, which are threaten by potential underwater explosions. This work aims to study the dynamic behaviors and propose a damage evaluation approach of caisson wharf against underwater explosion. Firstly, based on both the underwater explosion loading test and underwater explosion test on the reduced-scale caisson specimen, a high-fidelity finite element analysis approach for numerically reproduce the dynamic behaviors of prototype caisson wharves against underwater explosions was proposed and verified. Secondly, the underwater explosion loadings and dynamic behaviors of prototype caisson wharf (14.9 m×8.1 m×10.95 m) against sequential blast wave and bubble pulsation of typical torpedo with a charge weight of 200 kg were studied. The influences of the seabed and cabin infill materials, as well as the explosion standoff distances of 3.4–10.2 m and depths of burst between 1/4 and 3/4 of water depth, on the blast resistance of caisson wharf were further examined through deflection distributions of exterior wall, damage evolution, and overall displacement of caisson wharf. Finally, a performance evaluation approach for prototype caisson wharves against underwater explosions was proposed by comprehensively considering the bearing, storage, and berthing capabilities. The corresponding protective measures and design recommendations were further provided. It indicates that: (i) under the explosion of a typical torpedo, the damage modes of prototype caisson wharf mainly involve the overall vibration, spalling and cracking of the exterior wall, collapse of the upper operating platform and cracking of the top plate;(ii) the blast wave and cavitation zone generated between the bubble and the exterior wall are the two primary causes of damage to caisson wharf;(iii) compared to the saturated calcareous sand seabed, the assumption of rigid seabed underestimates the spalling on the exterior wall, which is not recommended for scenarios where cavitation zones may generate;(iv) rock rubble is the most effective infill material in improving the blast resistance of caisson wharf among four types of infill configurations, i.e., fully filled and half-filled saturated calcareous sand, rock rubble and pure water;(v) the standoff distance of 10.2 m is regarded as a secure protective range in the scenarios discussed currently. As the standoff distance decreases and the depth of burst increases, the spalling of the exterior wall induced by the cavitation intensifies, posing a great threat to the functionality of caisson wharf.
文摘Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not without consequences for the countries concerned. Benin, a country in the Gulf of Guinea, is no exception to this phenomenon because, due to its maritime history, it has a heritage of port structures. These structures, built on its coastline, cause a wide variety of environmental problems such as silting and erosion on either side of them. The general objective of this article is to contribute to the proper functionality of port facilities while minimizing environmental problems that may arise. It aims to provide managers with a tool allowing them to fully understand the state of their assets in order to rationalize maintenance actions. In order to achieve this objective, an assessment of the state of the structure, and then a structural diagnosis are necessary and recommendations can be established to restore the level of service of the latter. As a result, two examples were presented: the wharf of the Sèmè-Podji pipeline project and the maritime piles project of the Wasco de Gama bridge (control project), and recommendations adapted to this objective were established. The comparative analysis of the two examples, both maritime works, revealed an under-sizing at the level of the spans of the wharf bridge of the Sèmè-Podji pipeline project (spans of 7 m in length), while these spans vary on average by 45 m to 62 m for the Wasco da Gama bridge. Bringing the piles closer together at the Sèmè-Podji wharf reduces the energy of the current which promotes the accumulation of sediment. The structure no longer experiences a flow capable of setting in motion the sands accumulated since at least 2022. This element appears to be a fundamental characteristic explaining the erosion observed to the east of the structure.
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFC3102305)the Taishan Scholar Program of Shandong Province(Grant No.tsqn202211049)the Key Engineering Innovation Project of Shandong Province(Grant No.2019JZZY010301).
文摘This paper presents a new type of steel pipe pile wharf connection node.The steel pipe and concrete are connected by ultra-high performance concrete(UHPC)grouting to improve the bonding performance between the concrete and steel pipe and enhance the mechanical performance of the specimen under earthquake action.A bond test between the steel tube and the concrete was carried out.Considering the interaction between materials,the proposed concrete constitutive model was proposed.The finite element analysis method was used to simulate the structural response of the UHPC grouting connection concrete-filled steel tube(UCFST)beam-pile joint and the normal strength concretefilled steel tube(NCFST)beam-pile joint under earthquake action.The results indicate that the bond performance between the UHPC and the steel tube is stronger.The UCFST specimen has a relatively high bearing capacity and stiffness.When the ratio of the UHPC grouting layer to the component diameter is 0.5,the bearing capacity is the highest.When the ratio is 0.37,the ductility is the highest.When the ratio is 0.25,it combines the advantages of the two situations mentioned above.UCFST specimens have better energy dissipation capacity and damage,which can effectively improve the seismic performance of components.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52371277)the State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation (Tianjin University)(Grant No. HESS-2323)+2 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province (Grant No. KYCX24_4071)the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515010890)the Open foundation of Key Laboratory of Port.Waterway&Sedimentation Engineering (Grant No. Yk224001-1)。
文摘This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-source software Open FOAM~?, a two-dimensional viscous-flow numerical wave flume was developed to simulate the fluid resonant motions induced by transient focused wave groups with different spectral peak periods and wave amplitudes. The results indicate that for all the incident focused wave amplitudes considered, the amplitudes of the free surface elevation in the gap, horizontal wave force and moment all exhibit a bimodal variation trend with increasing spectral peak period. The peak values of the above amplitude-period curve appear near the resonant period of the first and second harmonic components of the free surface elevation. However, the variation in the vertical wave force versus the spectral peak period presents different patterns. In addition, the first-to fourth-order harmonic components in the wave surface and forces are further examined via the four-phase combination method. The results show that the first-to secondorder harmonic components play a dominant role in the overall amplitude.
基金supported bythe National Natural Science Foundation of China(Grant No.40776053)
文摘High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate large tonnage vessels, wharves should be eorrstructed in deep water gradually. However, conventional high-pile and beam-slab structares are hard to meet the requirements of large deep-water wharf. According to arch＇ s stress characteristics, a new type of wharf with catenary arched longitudinal beams is presented in this paper. The new wharf structure can make full use of arch＇s overhead crossing and reinforced concrete compression resistance, improve the interval between transverse bents greatly, and decrease underwater construction quantity. Thus, the construction cost cab be reduced. Take the third phase project of the Yangshan Deep-water Port for example, comparative analysis on catenary arched longitudinal beams and conventional longitudinal beams has been made. The result shows that with the same wharf length and width, the same loads and same longitudinal beam moment, catenary arch structure can improve the interval between bents up to 28 m, decrease the nmnber of piles and underwater construction quantity.
基金financially supported by the Education Commission Fund of Chongqing(Grant No.KJ1500518)the Science Commission Fund of Chongqing(Grant No.cstc2016jcyjA0123)the Open Fund of Key Laboratory of Regulation Technology for Inland Waterway in Transportation Industry of Chongqing Jiaotong University(Grant No.NHHD-201506)
文摘All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method （FEM） and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the ＇plastic hinge＇. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom （SDOF） system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51709093 and 51679081)Fujian Provincial Department of Transportation Science and Technology Development Project (Grant No. 201708)Hohai University Student Innovation and Entrepreneurship Training Project (Grant No. 201910294014Z)。
文摘As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage detection methods are greatly limited in their application to pile foundation in service. In the present study, a new method for pile foundation damage detection is developed based on the curve shape of the curvature mode difference(CMD) before and after damage. In the method, the influence at each node on the overall CMD curve shape is analyzed through a data deletion model, statistical characteristic indexes are established to reflect the difference between damaged and undamaged units, and structural damage is accurately detected. The effectiveness and robustness of the method are verified by a finite element model(FEM) of high-pile wharf under different damage conditions and different intensities of Gaussian white noise. The applicability of the method is then experimentally validated by a physical model of high-pile wharf. Both the FEM and the experimental results show that the method is capable of detecting pile foundation damage in noisy curvature mode and has strong application potential.
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2007AA11Z130)
文摘In the present study,the formula calculating ship impact forces on light wharf structures is presented when the elastic deformation of the hull and the pier structures as well as the nonlinear deformation of the fender are taken into account. The ship impact forces are statistically analyzed with the Monte-Carlo method according to the known probability distribution types of random variables.Based on the simulated results, the distribution of ship impact forces which is characterized by bimodal distribution can be expressed as the combining probability density function of beta distribution and normal distribution. The corresponding parameters of the probability density function can be estimated with the maximum likelihood method. The results show that ship impact forces on light wharf structures follow the distribution of type I extreme value.The mean coefficient and variation coefficient are 1.11 and 0.008 respectively during 50 years of design reference period.
基金financially supported by the Major Science and Technology Project of MOT,China(Grant Nos.2013 328 224 070 and 2014 328 224 040)the National Natural Science Foundation of China(Grant No.51409134)
文摘There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications.
文摘Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily damaged.Once the structure of high-pile wharf destroyed,it is bound to be a great threat to the safety of various facilities and personnel in the port.Given all of that,the multi-level comprehensive evaluation method based on the extension theory is proposed in this paper.Using this method to assess the safety of high-pile wharf structure,the reasonable advice on its maintenance and reinforcement can be given in time.What’s more,the method is simple and can give more objective result of the evaluation.
文摘A bold innovation was carried out for the structural type of wharves in line with local conditions in Chiwan Port, in which a group of wharves with novel structures have been built in this port during the past ten years.
基金National Natural Science Foundation of China under Grant Nos.42072310 and 51808307。
文摘Earthquake investigations have shown that near-fault pulse-like(NF-P)ground motions have unique characteristics compared to near-fault non-pulse-like(NF-NP)and far-field(FF)ground motions.It is necessary to study the seismic response of pile-supported wharf(PSW)structures under NF-P ground motions.In this study,a three-dimensional finite element numerical model is created to simulate a PSW.By imparting three types of ground motion,the engineering demand parameters(EDPs)of PSW under NF-P ground motions were analyzed and compared,in which EDPs are the maximum displacement and bending moment of the piles.Twenty intensity measures(IMs)were selected to characterize the properties of ground motions.The correlation between IMs and EDPs was explored.The results show that the piles present larger displacement and bending moment under NF-P ground motions compared to NF-NP and FF ground motions.None of the IMs have a high correlation with EDPs under NF-P ground motions,and these IMs are more applicable to FF ground motions.The correlation coefficients between EDPs and IMs under three types of ground motion were obtained,which will provide a valuable reference for the seismic design of PSWs.
基金Sponsored by General Project of Natural Science Foundation of Beijing (8212009)Tip-top Young Talents Training Program of High-level Teacher Team Construction Support Plan in Universities Affiliated to Beijing Municipality in 2019 (CIT&TCD201904010)Key Projects of Science and Technology Winter Olympics of National Key Research and Development Program (2020YFF0304900)。
文摘In the process of rapid development of urbanization and constant adjustment of urban space,urban characteristics are faced with many challenges.Taking Taiping Bay wharf area of Yantai City as an example,the paper sorts out the spatial construction problems from the aspects of historical development,urban texture and cultural characteristics by exploring the research process and methods of regional urban design,and put forward optimization strategies from the perspectives of urban structure optimization,street image design,industrial building transformation and cultural space establishment based on the characteristic resources of the area,thus providing experiences for future regional urban design.
文摘Occupational health management of liquid chemical transport wharf is still in its infancy,to grasp the occupational health status of employees in the industry and improve the occupational health management level of employees,taking the liquid chemical transport wharf of an enterprise as the investigation object,according to the relevant domestic occupations.Hygiene standards,using the combination of on-site occupational hygiene survey and workplace occupational hazard factors detection,identify the occupational hazard factors of the wharf and detect the degree of hazard.The survey results show that the overall occupational health of the wharf is basically good,but the noise index is slightly exceeded.It is suggested to further improve the occupational health management level of the wharf by improving the protection technology and strengthening the administrative management.
文摘This paper introduces the main construction types of inner fiver whar~ analyses the developing trend of the construction types of wharf in mountainous areas, point out that suspended vertical wharf is the main construction type for deep-water, huge water fluctuation river terminals. Opentype wharf on pilcs is also a new- type wharf structure in mountainous areas with great water fluctuation.
文摘foundation settlement is one of the common problems in the construction and use of gravity wharf. Causes gravity type wharf foundation settlement reason is very complex. Based on the full understanding of the concept of gravity quay wall, this paper analyzes the reasons of the foundation settlement of gravity wharf. And Put forward the corresponding prevention and countermeasures.
文摘Gravity wharfis a kind of wharf which is widely used. At the dock construction, usually meet various such as trench back silt, rear edge backfill, rail displacement settlement of a series of; control of these problems and solve for the construction quality of the pier is very heavy. Based on some experiences in the construction of wharf, this paper puts forward some methods to solve and control some of the above problems.
文摘As the stiffness discontinuous of large diameter steel tube and concrete combined pile, the complicated stress state is caused by the combination of the pile foundation and the base rock, the steel casing and the bedrock structure. It is needed to put forward a scientific basis to determine the pile foundation effective depth of embedded. For this purpose, the physical model and the numerical model of single pile with large diameter steel tube and reinforced concrete combined force are established. Through numerical simulation and contrast test of a large number of variable parameters, the various factors that affect the lateral bearing capacity of the embedded piles are discussed in detail, the mechanical properties of the foundation under the action of the steel tube and the pile foundation are obtained.
文摘Combined with practical engineering, based on the introduction of soil arching theory, we explore the impact of barrier piles in blind sheet-pile bank connecting structure. Besides, we build a plane strain model by ABAQUS sot＇cware to study the impact of cross section type, the pile spacing and soil properties on soil arching effect. We find that cross section type of the pile has a certain influence on soil stress distribution in front of the barrier piles by comparing circular cross section and rectangular cross section. We also find that clear distance between the barrier piles and cohesive force of the soil have a great influence on that impact. We can increase clear distance between the barrier piles appropriately to improve the efficiency of construction and reduce the proiect cost.
