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Many high-piled wharves were built in the last century, and some wharf members have been damaged over decades of operation. It is important to use effective means to evaluate the safety status and durability of these high-piled wharf structures and guide reinforcement efforts. At present, the most common safety status evaluation methods for high-piled wharves are site inspections, crack detection, and concrete strength tests. However, it is difficult to provide quantitative safety indicators using these methods. In this paper, a disturbing-energy method is proposed for the safety assessment of high-piled wharves based on the variational principle and minimum potential energy principle. The geometric nonlinear effect is introduced, and formulations are derived for calculating the disturbing energy. A concentric compression bar example is presented to validate the proposed method through a comparison analysis between the Euler method and disturbing-energy method. Through several cases involving different loads applied to the same high-piled wharf structure, the same load applied to different structures, overall stiffness degradation, and member damage, the disturbing-energy method is shown to reflect very well the safety condition or damage condition of the high-piled wharf structure. The disturbing-energy method can also be used to identify the failure path of the structure and optimize the form of the wharf structure. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of open gaps caused by differential settlement in the process of constructing sluice buildings in soft soil beach areas, combined with the construction of sluice and supporting facilities in a reclamation project. First, the change rules for the shear strength and compression modulus of soft soil under different consolidation degrees are studied by theoretical analysis. Then, an interaction model for soft soil and pile soil is established using the geotechnical finite element analysis software MIDAS/GTS NX. The change rules for the vertical and horizontal ultimate bearing capacities of a single pile with the degree of soil consolidation are studied. On this basis, a three-dimensional numerical analysis model of drainage sluice, seawall, cofferdam, and foundation soil is established, and the relationship between the degree of soil consolidation and the development of structural gaps caused by differential settlement is obtained. The research results show that the bearing capacity of a single pile increases greatly with the consolidation of soil around the pile and that the gap width between the structures in the project decreases with increasing consolidation. This paper provides a theoretical basis for the prediction of pile bearing capacity in the preliminary design stage and the evaluation and calculation of differential settlement of intersecting buildings in soft soil beach areas. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of heterogeneity on mechanical and acoustic emission (AE) behaviours of stratified rock specimens under uniaxial compression using a digital image processing (DIP)-based finite difference method (FDM). In the DIP, a developed image segmentation algorithm based on seeded region growing (SRG) is proposed to fully acquire the mesostructure of stratified rock specimens, instead of the traditional threshold value method. To sufficiently capture the heterogeneity of stratified rock, Weibull statistical manner is adopted to describe mechanical properties of each material component. Three schemes are adopted to study the effect of heterogeneity with different homogeneity index and different mesostructure under two compression loading conditions. The results show that heterogeneity has a great influence on the mechanical and AE behaviours of stratified rock. As the homogeneity of material components increases, the peak strength and brittleness of rocks increase, and the macro elastic modulus improves as well. Simultaneously, the AE modes change from swarm shock to main shock. Under the same component content, the macro-property is better while the component distribution is concentrative relatively, especially to the property of strength. For the coupling effect of mesostructure and heterogeneity arising from material components, mesostructure is considered to cause the visible increase of AE counts. And the numerical results agree well with the previously numerical results and experimental data. [ABSTRACT FROM AUTHOR]

The disturbance of the soil behind the reaction wall of an open caisson can affect the efficiency and safety of jacking operation and control. This study focuses on the deformation of the soil mass behind the reaction wall used to support the jack. The stress-strain relationship of the soil behind the reaction wall was analysed, providing a theoretical basis for determining the most unfavourable combination of reactive forces using a computational model. A three-dimensional finite element model for this problem was developed, and a simple loading scenario was implemented. In addition, the mechanism of the deformation of the soil induced by horizontal parallel pipe jacking was also analysed. The results showed that for the soil behind the reaction wall of the open caisson, the uplift deformation of the soil surface increased initially and later gradually decreased, eventually achieving stability. The reaction force had a relatively obvious effect on the deformation of the soil within the range of the reaction wall burial depth and the horizontal displacement of the soil along the length of the reaction wall. The maximum displacement occurred near the axis of symmetry of the reaction wall. In addition, to consider the cyclic characteristics of the reaction force, the shakedown theorem is introduced to the deformation analysis of the soil and compared with the results obtained from simple loading. It was shown that the two deformation analysis methods have certain scopes of application, depending on the individual engineering requirements. [ABSTRACT FROM AUTHOR]

Summary: Health monitoring, detection, and safety assessment of high‐piled wharf structures are key problems to be solved urgently in the field of maritime transport engineering. An optimal method for placing accelerometers for monitoring a high‐piled wharf structure is presented in this paper. In this method, a partitioned genetic algorithm strategy is proposed based on the frequency and vibration modes of the high‐piled wharf obtained by a modal analysis using the finite element method. The modal assurance criterion matrix is used as an evaluation index of sensor placement results. Subsequently, the sensor placement scheme obtained by the proposed method is applied to a reduced‐scale model of a high‐piled wharf to validate the method. The results demonstrate that the proposed sensor optimal placement method reduces the number of accelerometers and improves the calculation efficiency by ensuring relatively complete information on the high‐piled wharf structure. [ABSTRACT FROM AUTHOR]