Seismic response and correlation analysis of a pile-supported wharf to near-fault pulse-like ground motions

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.

Study on Structure of Arched Longitudinal Beams of Deep-Water Wharf

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.

Simplified Calculation Methods for All-Vertical-Piled Wharf in Offshore Deep Water

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.

A Method for the Damage Detection of Pile Foundation in High-Pile Wharf Based on A Curvature Mode Deletion Model

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.

Dynamic Characteristics and Simplified Numerical Methods of An All-Vertical-Piled Wharf in Offshore Deep Water

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.

Statistical Analysis of Ship Impact Forces on Light Wharf Structures

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.

BIM技术在高桩码头桩基施工中的应用

BIM技术在水运工程中应用尚属于起步阶段。依托国内某高桩梁板码头项目,对基于BIM技术的桩基碰撞检验和沉桩过程模拟应用进行研究,提前消除交叉和碰桩问题,保障桩基顺利施工,可为同类型应用场景提供参考。

The Research on Safety Evaluation of High-pile Wharf Structure

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.

New Types of Wharf Structures in Chiwan Port

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.

Urban Space Reshaping Based on Regional Urban Design:A Case Study of Urban Design of Taiping Bay Wharf Area in Yantai City

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.

Investigation of Occupational Hazards in Transport Wharf of Liquid Chemicals

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.

The construction types of inner river wharf with huge water fluctuation and their development

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.

Causes and prevention measures of foundation settlement of gravity type wharf

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.

Research on construction technology of gravity wharf

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.

Study on the Embedded Mode of Large Diameter Steel Tube and Concrete Combined Pile

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.

Analysis of Soil arching effect for Blind sheet-pile wharf based on ABAQUS

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.