The publisher of Geotechnical Research wishes to retract the article Lin D, Lin R, Zhou S, Wang H, Xiao Y, Bao J and Fei L (2025), “Effectiveness of anchor pile protection for metro tunnels under construction disturbances”. Geotechnical Research, Vol. 12 No. 3 pp. 141-154, doi: Link to the cited article.It has been brought to our attention by the authors that a large portion of this article is taken, without full and proper attribution, from an earlier work by Wang, H., Lin, M., Li, J. et al. Effects of construction disturbances on tunnel displacement and the protective role of soil reinforcement in metro tunnels. Sci Rep 15, 19780 (2025). Link to the cited article.The decision to retract has been informed by COPE’s guidelines on retractions and Emerald’s publishing ethics. Emerald’s editorial and originality policy guidelines make it clear that work submitted should be original, not infringe any existing copyright, or be currently under considered for publication by any other journal or publication.The authors cooperated fully with this investigation, and they also wish to acknowledge that the funding information featured in the article was not accurate due to a clerical oversight; the correct details are as follows: the authors would like to express their sincere gratitude to the Zhejiang Province Construction Research Foundation (Grant No. 2023K225) for the financial support of this study.The authors of this article would like to note that they agree with the content of this notice.The authors and publisher of the journal sincerely apologize to the readers.

The flocculation and sedimentation of suspended clay particles in marine environments are an important process to form natural marine clays. In this study, the process of flocculation and sedimentation is simulated using appropriate flocculating agents in the laboratory. A series of laboratory sedimentation tests are carried out on various floc samples prepared with different concentrations of flocculating agents, and the size and density of flocs are measured and are found to serve as good parameters to characterise the development of flocculation. Multiple series of undrained triaxial compression tests under normal consolidation, as well as under over-consolidation, are then carried out on a slightly flocculated sample and a largely flocculated sample, as well as an ordinary remoulded sample. The values of the undrained shear strength of the flocculated samples are compared with those of the ordinary remoulded sample. The largely flocculated sample exhibits a higher undrained shear strength under normal consolidation as well as under over-consolidation. A comparison with past studies on natural marine clays also indicates that the highly variable values of the undrained shear strength of marine clays can be attributed to the different levels of development of flocculated structures in clays.

Analysis and calculation of lateral pile load capacities using appropriate methods is a challenging task for geotechnical engineers. Primarily, piles in Dubai, UAE, are rock fully socketed with top strata of medium dense to dense silty sand or sedimentary rock resisting lateral loads. In this study, the results of two field pile lateral load tests were chosen for examining different methods used by local geotechnical engineers, where ground lithology constitutes fragile sandstone up to ∼8 m below ground level overlying extremely weak conglomerate/siltstone. Assessing the efficacy of design parameters and analysis methodology is a pivotal aspect in preliminary evaluation of the lateral load capacity of piles. In this research, two commonly adopted approaches (non-linear p–y analysis using the LPile software and finite-element analysis using the Plaxis 3D software) were assessed by comparing them with field test results to predict the lateral load capacity precisely. Design parameters were based on borehole data and laboratory tests near the test location. Even though finite-element analysis predicted better than non-linear p–y analysis, lateral load capacities were underestimated in both piles analysed, which was related to assessment of input parameters. In addition, finite-element analysis was used to back-calculate the elastic modulus of rock that yields lateral deflections of piles close to field test results.

The Harbor Bay Isle residential project in Alameda, CA, USA, comprises some 600 acres (243 ha) reclaimed from the margin of San Francisco Bay underlain by very soft (C c ∼ 1), high-water-content clay (e 0 > 2): San Francisco Bay Mud. Settlements of as much as 2.5 m developed from about 7 m (varying across the site) of sandfill surcharge, with records over some 43 years extending through primary consolidation and into secondary consolidation (creep). Iterative numerical modelling using large-strain theory (implemented in the Microsoft Excel software program), constrained by in situ void ratios and oedometer trends, achieved close matches with settlement histories over the full 43 years for the three locations considered, each of which displayed a markedly different history from the others. The presence or absence of a dried ‘crust’ was found unimportant; instead, the proportion of subunits within the Bay Mud controlled the evolution of settlements. Subunits within Bay Mud, evident in modern cone penetration test soundings (which were not available during the reclamation works), exist across the region and have systematically different states and properties. Further, while ageing is a factor, depositional conditions of the Bay Mud have produced a residual fabric that presents as a component of the pre-consolidation pressure.

Bio-cementation is a new sustainable approach that has gained popularity due to its low energy and carbon dioxide footprint compared with those of existing technologies for geotechnical and geoenvironmental engineering applications. Bio-cementation is a soil improvement technique that involves binding the pore space of soil particles with calcium carbonate minerals by microbially induced carbonate precipitation (MICP) and filling the soil pore space. The purpose of this paper is to present the current state of the art and a comprehensive discussion on the development of bio-cementation for soil improvement/reinforcement. Premixing, injection, immersing and surface percolation are identified as four distinct bio-cementation treatment techniques. Furthermore, scholars have reported employing ureolytic bacteria such as Sporosarcina pasteurii, Bacillus sphaericus and Lysinibacillus sphaericus isolated from corals, limestone caves, soils, waste materials, seawater and other sources to accomplish effective bio-cementation. Some of the major issues (bacterial cultivation costs and ammonium production) that impede its industrial potential and promising remedial techniques are also discussed. This state-of-the-art review also discusses the benefits and drawbacks of bio-cementation compared with traditional approaches. The significance of enzyme-induced carbonate precipitation as a soil bio-cementation alternative to MICP is also highlighted. Finally, the sustainable procedure, bio-cementation principles and future implications are discussed.

In this study, the dynamic response and instability of a low-permeability deformable caisson-type quay wall (CQW) with backfill soil exposed to standing waves is evaluated. The focus is on the dynamic response and instantaneous liquefaction of seabed and backfill around the CQW. This study aims at closing the knowledge gap about the wave-induced CQW–seabed response without the presence of a breakwater, as the bulk of the prior research has been done on CQWs considering earthquakes as the primary loading source. Finite elements are used, and numerical results are obtained in terms of displacements, pore-pressure and shear stress variations in temporal and spatial domains. Wave-induced instantaneous liquefaction is analysed, and analyses are performed to determine the effect of soil/wave properties on dynamic response and liquefaction. Results indicate that there is considerable liquefaction potential in both seabed and backfill that may play a key role in the stability of the CQW. While such a response is dependent upon the induced wave energy and the CQW motion, seabed parameters alter the instantaneous liquefaction occurrence as well. A slight decrease in the seabed degree of saturation causes a contraction behaviour under the wave-induced motion of the CQW, which, in turn, affects the mechanism of response and the initiation of instability in the seabed.

Many highways have been built on the eastern coast of China in the past decades. Recently, some engineering problems have emerged after long-term operation. Due to the different properties between the underlying soil and bridge pile foundations, the problem of bumping at the bridge head is inevitable. To study the potential causes and provide insight for future improvement, the settlement of typical highways in the Hangzhou Bay area, which had been open to traffic for more than 10 years, was investigated. After an analytical calculation with the verification of the numerical method and field data, it was indicated that long-term deformation was mainly caused by the poor properties of the lower of the two layers that make up the underlying soil. The trend of the variation of the lower layer keeps increasing at a slow rate during the construction period, resulting in sustained and rapid changes during the following years. Different kinds of ground improvement such as lightweight materials and soil–cement columns generated by deep mixing or jet grouting methods are discussed. The improvement of the lower layer will be more effective. With the analytical method, it is convenient and efficient to calculate and analyse the settlement at different periods, which is significant for design.

Finite-element analyses using critical state theory proved necessary to understand the development of static liquefaction during three recent large tailing dam failures at Fundao (in Brazil), Cadia (in Australia) and Brumadinho (in Brazil). However, the complexity of these events prevents these analyses being viewed as a complete validation of the methodology. Here the authors evaluate a far simpler case of static liquefaction: the 1974 Tar Island slump (in Canada). This upstream slump involved a rapid drop of 5 m during construction of a 12.5 m high upstream raise over loose tailings. While not a dam stability issue, the event has the attraction for validation of being load-induced, with simple geometry, and with known material properties and in situ state. The computed liquefaction develops from a prior drained condition before propagating rapidly undrained – there are similarities to the video record at Brumadinho (an animation is provided as online supplementary material to illustrate this). A range of scenarios are explored, with the base case of taking reported conditions at face value giving deformations close to those measured. An important aspect was using elastic shear moduli determined by geophysical methods. The analyses were carried out with commercial software (Plaxis) and used critical state theory with largely familiar soil properties measured by standard methods.