Bibliometric analysis of stone column research trends: A Web of Science perspective

1.1 Research focus

With the rapid growth of research in this field, it becomes crucial to map the landscape of stone column literature and identify the key contributors, emerging trends, and potential future directions. Bibliometric analysis, a quantitative approach to studying scientific literature, offers a powerful tool for achieving this objective. This study aims to conduct a comprehensive bibliometric analysis of scholarly research on stone columns, utilizing data from the Web of Science (WoS) database, a renowned source for scientific publications. By analyzing publication trends, influential journals, key research institutions and authors, geographical distributions, and thematic patterns, this study seeks to provide a comprehensive understanding of the stone column research domain within geotechnical engineering. The vast body of research on stone columns will be examined, and important studies, innovations in technology, and trends will be noted through bibliometric analysis using the WoS database. As illustrated in Figure 2, our goal is to find the answers through this analysis.

Figure 2

Research mapping for stone column studies: Key inquiry areas.

2.1 Data source

The WoS database was selected as the primary data source for this study due to its extensive coverage of high-quality scientific literature across various disciplines, including geotechnical engineering. The WoS database is renowned for its comprehensive indexing of peer-reviewed journals, conference proceedings, and other scholarly publications, making it a reliable and authoritative source for bibliometric analysis.

2.2 Search strategy

A comprehensive search string was formulated to retrieve relevant publications related to stone columns. The search string was designed to capture variations in terminology and ensure a comprehensive collection of relevant literature. The search string used in this study is shown below:

TS = (((“stone column*” OR “gravel column*” OR “vibro stone column*” OR “vibro-stone column*” OR “geosynthetic encased stone column*” OR “granular column*”) AND (“soft soil*” OR “soft ground*” OR “clay*” OR “silt*” OR “mud” OR “peat” OR “organic soil*”)) OR ((“stone column*” OR “gravel column*” OR “vibro stone column*” OR “vibro-stone column*” OR “geosynthetic encased stone column*” OR “granular column*”) AND (“geotechnical engineering” OR “soil improvement” OR “ground improvement” OR “soil stabilization” OR “soil reinforcement”)) OR ((“stone column*” OR “gravel column*” OR “vibro stone column*” OR “vibro-stone column*” OR “geosynthetic encased stone column*” OR “granular column*”) AND (“development*” OR “innovation*” OR “advancement*” OR “performance*” OR “efficacy” OR “optimization” OR “numerical modeling” OR “experimental study” OR “case study” OR “field study” OR “design criteria” OR “sustainability”))).

This search string utilizes the “Topic Search” field in the WoS database, which searches for the specified terms in the title, abstract, author keywords, and Keywords Plus^® fields. The use of Boolean operators (OR, AND, NOT) and wildcard characters (*) ensured the inclusion of publications containing variations of the term “stone column” while excluding irrelevant content. The data of each manuscript were thoroughly examined for specific details such as author affiliations, publishing language, journal titles, publication year, publishers, geographical regions, keywords, and citation counts [48–50]. It should be noted that citations and publication counts may exhibit modest variations due to the fact that the data was gathered on a specified date, namely September 27, 2023. Any modifications made to the database after this date may result in inconsistencies.

2.3 Data extraction and curation

Publications from 1975 to 2023 were retrieved from the WoS database using the defined search string. The extracted data underwent a rigorous curation process to eliminate duplicates, correct inconsistencies, and ensure the relevance of each publication to the study’s objective. This process involved the following steps:

1. Removal of duplicate entries based on unique identifiers such as digital object identifiers or accession numbers.

2. Verification and correction of metadata fields, including author names, publication years, journal titles, and other bibliographic information.

3. Manual inspection of titles, abstracts, and keywords to exclude publications that were not directly related to stone column research.

4. The curation process was essential to ensure the reliability and accuracy of the dataset, as well as to facilitate meaningful analysis and interpretation of the results.

2.4 Data analysis

The curated dataset was analyzed using Excel and VOSviewer software. VOSviewer is a popular tool for bibliometric analysis, allowing for the visualization and exploration of bibliometric networks and trends. The analysis techniques employed in this study included:

3.1 Document and language type

The bibliometric study of publications on stone columns identified a wide variety of document types as shown in Figure 4. Of these, articles made up the majority (477 publications), indicating the depth of study and scholarly discussion in this area. There were 9 publications consisting of editorial materials that provided insights and overviews. This indicates a modest but important addition to the field. Significantly, there were 10 publications categorized as “Article; Early Access,” which underscores the continuous and emerging research patterns. As detailed in Table 1, five reviews indicate a convergence of current knowledge, providing detailed summaries of the subject. Furthermore, four publications were found to be “Article; Proceedings Paper,” suggesting that there were lively discussions and information sharing at scholarly conferences. The distribution of research in geotechnical engineering, specifically focused on stone columns, highlights the diverse and ever-changing nature of this discipline. It demonstrates a balanced combination of ongoing research, expert viewpoints, and comprehensive evaluations.

Figure 4

Analysis of document types in academic publishing.

The bibliometric study reveals a significant language distribution in the publications, as depicted in Figure 5 and summarized in Table 2. The bibliometric study reveals that 502 out of the 505 total publications are in English, indicating a majority of English in the publications. This emphasizes how widely used and accepted English is as the main language of research worldwide, particularly in the subject matter being studied. There are very few publications in Spanish and German – just two and one, respectively. This distribution points out the linguistic focus of research distribution and raises the possibility of linguistic obstacles in the sharing of knowledge in this field.

Figure 5

Analyzing and comparing publications based on language.

3.2 Publication year trends

The analysis of publication trends over the years revealed a steady increase in the number of publications related to stone columns, with notable spikes in certain years (Figure 6). These spikes may be attributed to significant developments, landmark studies, or dedicated conferences and symposiums focused on stone column research. The upward trend in publication output reflects the growing interest and importance of stone column research within the geotechnical engineering community. The spikes in specific years could be indicators of breakthroughs or advancements that attracted heightened attention and sparked further research efforts. The bibliometric examination of articles on stone columns from 1975 to 2023, as illustrated in Figure 4, shows significant trends in research and citations. The data depicted in this figure clearly indicate the evolution and growing interest in this area over time. In its early stages, the discipline experienced limited activity, with only four publications from 1975 to 1985. However, these papers received significant citations, suggesting that they laid the groundwork for future research. During the 1990s, there was a steady increase in interest, with a significant rise in citations in 1995 and 1996, indicating important research conducted during this time. In the early 2000s, there was a consistent rise in the number of published works. However, in 2004, there was a significant spike, with seven papers receiving a total of 536 citations. This period was characterized by a series of notable research projects. In 2007, there were eight articles that received a notable 975 citations, demonstrating significant progress in the discipline. An evident increase in research activity was noted starting in 2011, reaching its highest point in 2018, with a total of 40 publications. Despite the continued high number of publications in the following years, there was an apparent decrease in citation counts, which may have been due to the recentness of the publications. In 2021, there was a notable increase in the number of publications, reaching a peak of 56. However, the citation rate was comparatively lower, indicating the presence of growing research fields that have not yet gained widespread attention.

Figure 6

Patterns of publishes and impact citations over the year.

Despite being incomplete, the data from 2023 already indicate 47 articles, indicating a sustained high level of interest in the topic. In general, the rising quantity of published works over time demonstrates the increasing significance and changing characteristics of research on stone columns in the field of geotechnical engineering.

3.3 Top journals

The analysis identified several influential journals that have been instrumental in disseminating research on stone columns (Figure 7). These journals span the broader geotechnical engineering domain as well as niche areas related to ground improvement techniques. The dominance of certain journals underscores their pivotal role in shaping the discourse and serving as primary sources of knowledge for researchers and practitioners.

Figure 7

Evaluation of journals on the basis of publication volume for stone column research.

Prominent journals such as Geotextiles and Geomembranes, International Journal of Geomechanics, Computers and Geotechnics, and Journal of Geotechnical and Geoenvironmental Engineering have published a significant number of articles on stone column research. These journals cover a wide range of topics within geotechnical engineering, reflecting the multidisciplinary nature of the field and the diverse applications of stone columns.

Table 3, which provides a detailed breakdown of journals like Geosynthetics International, Soil Dynamics and Earthquake Engineering, and Transportation Geotechnics have also contributed significantly to the dissemination of stone column research. These journals focus on specific aspects of geotechnical engineering, such as geosynthetics, seismic behavior, and transportation infrastructure, highlighting the relevance of stone columns in addressing various challenges within these domains.

The dominance of certain journals in this list underscores their pivotal role in shaping the discourse around stone columns. For researchers, these journals can serve as primary sources of cutting-edge knowledge and also as potential outlets for publishing their work.

3.4 Key research institutions

The study highlighted the leading research institutions and authors contributing to the field of stone column research (Figure 8). These institutions and authors serve as hubs of expertise, driving advancements through their consistent contributions and collaborations. Their work not only reflects the historical context but also provides insights into potential future trajectories. Among the top research institutions identified in the analysis are Islamic Azad University, Tongji University, Hunan University, Hohai University, and the University of California, San Diego, as seen in Table 4. These institutions have produced a significant number of publications and received substantial citations, indicating their influential role in shaping the stone column research domain.

Figure 8

Comparative evaluation of top 20 institutions’ citation counts and publication activity.

3.5 Top authors

The bibliometric analysis of stone columns in geotechnical engineering demonstrates significant contributions from important academics in the field. Figure 9 illustrates the distribution and impact of publications by these key authors, offering a visual representation of their academic influence. With 20 and 18 publications, respectively, and a high citation count, Kousik Deb and Jorge Castro stand out as prominent figures in the field. The h-index of 25 for both authors indicates a consistent level of impact and quality in their study. Table 5 provides a detailed breakdown of the publication metrics, including h-index and i10-index for these authors. With only 10 articles, Buddhima Indraratna stands out for having an impressive h-index of 85 and an i10-index of 415, indicating that his work is exceptionally significant and widely cited. Cholachat Rujikiatkamjorn and Jie Han both have a high h-index and i10-index, highlighting their significant contributions to the field. They also have a lot of influence with nine and eight publications, respectively. With an h-index of 33, V. Sivakumar’s contribution is remarkable, even if he only has eight publications.

Figure 9

Productivity and impact of top ten authors: publications and citations analysis.

With eight publications, Wu Chosen, Chen Jianfeng, Gangqiang Kong, and Hong Yungshan are recognized for their contributions in the analysis. Comparing themselves to the top contributors, their lower h-index and i10-index indicate that they are gaining traction in the field. The authors’ varying levels of impact and engagement within the scientific community are indicated by the differences in their h-index, i10-index, and number of citations. This variation highlights both established and up-and-coming researchers in the field, underscoring the dynamic character of geotechnical engineering research in general and the study of stone columns in particular.

3.6 Geographical distribution

The geographical distribution of research output revealed the global interest and regional strengths in stone column studies. Countries with significant contributions often align with regions facing specific geotechnical challenges or those with a rich tradition of geotechnical research. This distribution highlights potential research hubs and opportunities for international collaborations. The data from the bibliometric analysis focusing on stone column studies, as illustrated in Figure 10 and detailed in Table 6, reveals a distinct global distribution. The People’s Republic of China leads with 140 publications and 1,942 citations, demonstrating its importance in promoting this topic. India comes in second with 103 articles, but tops China in citations with 2,966, demonstrating that its research has had a significant influence. The United States ranks third, with 79 publications and a significant 2,495 citations, showing the country’s influential research presence.

Figure 10

Scholarly publications distribution worldwide by country (a) and (b).

Iran, Australia, and the United Kingdom appear to be significant contributors. Iran’s 54 articles, despite being smaller in number, have received 774 citations, demonstrating their importance. Australia has a significant influence, with 1,282 citations despite having 38 publications. England’s 37 publications, which are nearly identical to Australia’s, have 1,152 citations.

Spain, Canada, and Turkey have shown notable interest in this region. Spain’s 26 articles have received 607 citations, Canada’s 20 publications have received 640 citations, and Turkey has received 328 citations, suggesting an increasing interest in and contribution to the topic. Malaysia, with 15 papers and 164 citations, closes out the top ten, indicating an expanding presence in stone column research. Overall, these numbers show not just the geographical diversity of this topic but also the differing degrees of influence and research production between nations.

3.7 Research themes and emerging areas

The frequency of keyword occurrences in stone column studies bibliometric analysis, as illustrated in Figure 11 and summarized in Table 7, provides important insights into the field’s main areas and emerging trends. The most common keyword, stone column, appeared 107 times, closely followed by its plural form, stone columns, with 93 occurrences, emphasizing the study’s major focus. Geosynthetics and ground improvement, with 70 mentions each, highlight the significance of these materials and procedures in improving soil stability. The keyword consolidation appeared 50 times, demonstrating its importance in soil mechanics and stone column application.

Figure 11

Co-occurrence network of keywords in stone column studies (a) and (b).

The terms soft clay (49 occurrences) and soft soil (45 occurrences) reflect the primary challenges addressed by stone columns, whereas settlement (44 occurrences) and bearing capacity (36 occurrences) highlight the key benefits of using stone columns in geotechnical engineering. Liquefaction and embankment, with 30 and 28 citations each, indicate an emphasis on specialized applications of stone columns in seismic areas and for supporting structures. Less common but significant terms like granular column, soil enhancement, and numerical analysis imply specialized study sub-areas. Using terms such as discrete element method, geosynthetic, geotextile, model testing, analytical solution, and finite element analysis demonstrates the variety of methodologies and theoretical approaches used in this discipline. Overall, our keyword analysis depicts a broad and complex research environment that emphasizes both practical applications and theoretical advances in the study of stone columns.

3.8 Highly cited publications

In the results section of our bibliometric analysis focusing on stone columns in geotechnical engineering, the analysis of citations from the WoS Core Collection reveals significant insights. The most-cited article, with 276 citations, explores the behavior of stone columns through experimental and FEM analysis [16], highlighting the importance of combined practical and theoretical approaches in this field. A study that uses a two-dimensional Navier-Stokes model to understand granular column collapse comes in second with 255 citations [51]. This shows how important advanced modeling techniques are in geotechnical analysis.

Articles on the design of vibro replacement [52] and numerical evaluations of geosynthetic-encased stone columns [53], both vital for practical applications in soft soil improvement, follow closely in terms of citations, indicating the industry’s focus on enhancing foundation stability and soil reinforcement techniques. Several of the top 10 studies, with citation counts between 226 and 179, look at consolidation rates [54], improvement methods that use geogrids [55], and how single and group geosynthetic encased stone columns behave [56–58]. This suggests a growing research interest in optimizing stone column techniques and understanding their group dynamics. Additionally, articles exploring the application of stone columns as a countermeasure against soil liquefaction in non-plastic silty soils and their role in enhancing the bearing capacity of soft soils also feature prominently [25,59,60–62]. This reflects an increasing trend toward addressing soil liquefaction and foundation stability challenges, particularly in seismically active zones.

Figure 12 depicts this diversity by illustrating the range of topics showing the consistent presence of highly cited publications related to experimental investigations, numerical modeling, design methodologies, and performance evaluations underscoring the multidisciplinary nature of stone column research. These influential works have likely laid the foundation for further advancements and served as catalysts for subsequent research endeavors. Table 8 supplements this viewpoint by providing a detailed analysis of the specific study foci, emphasizing their importance in current geotechnical engineering.

Figure 12

Studies on stone columns: The most influential publications based on citations.

3.9 Research evolution and future directions

The bibliometric analysis of stone column research not only provides a snapshot of the current landscape but also offers insights into the evolution of the field and potential future directions. By examining the publication trends, keyword dynamics, and emerging themes, researchers can identify the trajectories and trajectories that the field might take. One notable observation from the analysis is the shift in research focus from static loading to dynamic loading conditions. While early studies concentrated on the performance of stone columns under vertical and horizontal static loads, more recent publications have explored their behavior under dynamic and seismic loading scenarios. This shift aligns with the increasing demand for resilient infrastructure and the need to address challenges posed by seismic activities in various regions. Additionally, the analysis revealed an emerging emphasis on sustainable structures and the integration of AI techniques. As the construction industry moves towards more environmentally conscious practices, researchers have likely directed their efforts toward exploring sustainable materials and construction methods for stone columns. Furthermore, the application of AI and advanced computational techniques holds the potential to optimize the design and performance of stone column systems, leading to more efficient and cost-effective solutions.

The identification of these emerging areas not only reflects the adaptability of the stone column research community but also points toward potential future research directions. Researchers may focus on developing innovative sustainable materials for stone columns, such as recycled or bio-based materials, and assessing their performance under various loading conditions. Additionally, the integration of AI techniques, such as machine learning algorithms and optimization methods, could lead to improved design methodologies and predictive models for stone column behavior. Furthermore, the bibliometric analysis highlighted potential research gaps or underexplored areas within the stone column domain. Topics such as slope stability in stone columns, performance in loose sand conditions, factor of safety considerations, and liquefaction mitigation strategies appeared to receive relatively less attention. Addressing these gaps could contribute to a more comprehensive understanding of stone column behavior and enhance their applicability in diverse geotechnical scenarios. Overall, the research evolution and future directions identified through this bibliometric analysis underscore the dynamic and responsive nature of the stone column research community. By adapting to emerging challenges, embracing sustainable practices, and leveraging advanced technologies, researchers can continue to drive innovation and develop effective ground improvement solutions for a wide range of geotechnical engineering applications.