Bibliometric and Social Network Analysis of Civil Engineering Sustainability Research from 2015 to 2019

Round 1

Reviewer 1 Report

It is an interesting paper. The scope and approach used is similar to a recently published paper, which has a much higher number of articles included in two databases.  

Luisa F. Cabeza, Marta Chàfer, and Érika Mata, 2020. “Comparative Analysis of Web of Science and Scopus on the Energy Efficiency and Climate Impact of Buildings” in Energies, Jan. 2020.

Some suggestions for improvement:

1. Provide the definition of “bibliometric analysis” and “Social Network Analysis” in the “Introduction” section.
2. Provide details on how the “Bibliometric analysis” and SNA was carried out. What programs or tools are used for the analysis, commercially available or in-house program? What level of automation is included in the analysis given the amount of information to process?
3. The current literature review is focused only on research that has been carried out in Civil Engineering Sustainability field. A review about “bibliometric analysis” and SNA analysis applied in this field will be useful to support the knowledge gap identified and justify the need of this paper.
4. P4 line 155: “In the civil engineering sustainability research, there are 65 different research directions from 2015 to 2019 (the distribution of research directions is shown in Figure 2).”. Please explain how the 65 research directions were determined.
5. Please elaborate a bit more on the importance of this paper and its contribution. The authors stated that “The purpose of this study is to conduct a comprehensive analysis of civil engineering sustainability research to clarify future needs and directions through integration of international literature published during the past five years (2015-2019).” May emphasize more on the future research needs and direction identified. These two aspects are a bit weak in the conclusions.

Author Response

Response to Reviewer 1 Comments

Point 1: Provide the definition of “bibliometric analysis” and “Social Network Analysis” in the “Introduction” section.


Response 1: Thank you for the comment and suggestion.

Based on the research of the basic theory of bibliometric analysis and social network analysis, the definitions of the two methods are presented in the revised manuscript which are expressed in red font, please see below

Bibliometrics is a quantitative analysis method of literature by applying mathematical and statistical methods [49], it can extract valuable information from massive literature data by statistical analysis of research fields, publications, countries, institutions, etc., and provide crucial support for subsequent research. As to SNA, it is a quantitative and visual analysis method developed by sociologists based on mathematics and graph theory which has been widely used in engineering construction [50], international trade [51] and knowledge management [52]. The SNA can use centrality analysis to study the nodes and connections of networks from a new perspective through the establishment of actors, ties and boundaries [53].

Point 2: Provide details on how the “Bibliometric analysis” and SNA was carried out. What programs or tools are used for the analysis, commercially available or in-house program? What level of automation is included in the analysis given the amount of information to process.

Response 2: Thank you for the suggestion.

According to your suggestion, we have carried on an in-depth explanation of relevant contents in the introduction. In this part, the details of the application, process and software of the two methods are provided in the revised manuscript, please see below.

In the process shown in Figure 1, some information needed for bibliometrics can be preliminarily obtained through the export of SCI and SSCI journal literature data related to civil engineering sustainability. After artificial adjustment and research of existing data, the bibliometric analysis can be carried out to determine the statistical results of research fields, publications, source countries and institutions. According to the preliminary statistical database, the co-occurrence relationship matrices of keywords and authors can be constructed based on the common occurrence frequency of keywords and authors in different literature. Then this research imports the above matrices into Gephi to construct research network and cooperation network to calculate the centrality, eigenvector centrality and betweenness centrality of the networks.

Point 3: The current literature review is focused only on research that has been carried out in Civil Engineering Sustainability field. A review about “bibliometric analysis” and SNA analysis applied in this field will be useful to support the knowledge gap identified and justify the need of this paper.

Response 3: Thank you for the comment and suggestion.

In order to illustrate the effectiveness of the two methods in literature research of civil engineering, some articles with similar methods are introduced in the last paragraph of the Introduction including the article you suggested. Then the application of these two methods in civil engineering literature research is described in the revised manuscript, please see below.

Bibliometrics is a quantitative analysis method of literature by applying mathematical and statistical methods [49], it can extract valuable information from massive literature data by statistical analysis of research fields, publications, countries, institutions, etc., and provide crucial support for subsequent research. As to the SNA, it is a quantitative and visual analysis method developed by sociologists based on mathematics and graph theory which has been widely used in engineering construction [50], international trade [51] and knowledge management [52]. The SNA can use centrality analysis to study the nodes and connections of networks from a new perspective through the establishment of actors, ties and boundaries [53].

Geng et al. [54] analyzed the articles of building life cycle assessment from 2000 to 2014 based on bibliometric analysis. The research of Yin et al. [55] shows that bibliometric analysis and knowledge network could effectively discuss the literature about building information modelling (BIM) and off-site construction. Cabeza et al. [56] carried out comparative analysis between the database: Web of Science (WoS) and Scopus in the energy efficiency and climate impacts of buildings through bibliometric. Oraee et al. [57] studied BIM-based Construction Networks as an example to quantitatively evaluate different research contents by the network analysis and bibliometric. Through the scientometric study of 501 off-site construction documents, Hosseini et al. [58] found the complement of existing research and indicated the importance of operation and management. Li et al. [59] made a bibliometric analysis of 1,874 BIM articles and determined the corresponding crucial research areas and clusters. Ganbat et al. [60] concentrated on the BIM risk management by reviewing 526 articles based on a database, Citespace, with the bibliometric method. Udomsap and Hallinger [61] selected 2,877 Scopus-indexed documents to study the hotspots of sustainable construction through bibliometric review and network analysis. In recent years, bibliometrics was employed to analyze the evolution of prefabricated building policies by Wang et al. [62].

Through the analysis of relevant research, it is found that the bibliometric analysis has been applied in the literature research of civil engineering especially in the research of BIM. Due to the development of library management, bibliometric analysis has been integrated into different databases such as WoS and Scopus. This phenomenon makes it possible to carry out important statistics and citation analysis in civil engineering literature research, and conduct further study through the Citespace.

However, the SNA is still in the development stage in the analysis of civil engineering literature, and current applications mainly based on three different softwares: (1) The direct visualization analysis method of articles in different databases based on VOSviewer; (2) Literature data analysis method based on traditional network analysis tools such as the Pajek; (3) Network visualization analysis of literature based on Gephi (An open source free cross-platform network analysis software based on java virtual machine) and text-processing. After comparing the three methods, it is found that Gephi has been widely adopted due to its advantages of visualization and data analysis.

Point 4: P4 line 155: “In the civil engineering sustainability research, there are 65 different research directions from 2015 to 2019 (the distribution of research directions is shown in Figure 2).”. Please explain how the 65 research directions were determined.

Response 4: Thank you for the suggestion.

In the process of deriving the articles from the WoS, we can make preliminary statistics about the selected articles. In the database of the WoS, the research direction of an article is determined according to the information when the article is uploaded. When some articles are selected as the analysis objects, the WoS can automatically make statistics according to the direction of the articles. The 65 research directions are determined in this way. In the revised manuscript, this situation is also described, please see below.

In civil engineering sustainability research, there are 65 different research directions provided by the basic statistics in the WoS from 2015 to 2019 (the distribution of research directions is shown in Figure 2). The four research directions of “Engineering”, “Environmental Science Ecology”, “Science Technology-Other Topics” and “Construction Building Technology” are relatively more focused than others, exceeding 10% of the overall articles. It can be seen that over a quarter of the research is engineering-related.

Point 5: Please elaborate a bit more on the importance of this paper and its contribution. The authors stated that “The purpose of this study is to conduct a comprehensive analysis of civil engineering sustainability research to clarify future needs and directions through integration of international literature published during the past five years (2015-2019).” May emphasize more on the future research needs and direction identified. These two aspects are a bit weak in the conclusions.

Response 5: Thank you for the suggestion.

We are sorry that the expression of this sentence in the manuscript is not clear enough. The purpose of this analysis is to find out the hotspots and shortcomings of existing research through the overall analysis of civil engineering sustainability, so as to provide reference for future research. In the revised manuscript, we rewrote the sentences, please see below.

The purpose of this study is to conduct a comprehensive analysis of civil engineering sustainability research to identify the hotspots and shortcomings of existing research, providing reference for future needs and directions through integration of international literature published during the past five years (2015-2019). The research process mainly includes three parts: (1) determination of the basic data source of published literature; (2) establishment and preliminary statistics of the network model of the published articles; (3) systematic analysis of the established network. Figure 1 shows the main roadmap of the analysis process of the paper.

Author Response File: Author Response.pdf

Reviewer 2 Report

Review comments are attached.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer 2 Comments

Point 1: First of all, the manuscript requires significant English improvement. Please revise it entirely by a native English editor and resubmit.

Response 1: Thank you for the suggestion. We have asked an English expert to check and revise the whole manuscript again carefully, especially for the English expression tried to avoid potential errors.

Point 2: L 68: Du et al. [31] used 8 bridges to analyze → type numbers smaller than 10. Therefore, instead of 8, you should type “eight”.

Response 2: Thank you for the suggestion. In the revised manuscript, we have changed the expression, please see below.

Du et al. [27] used eight bridges to analyze the different environmental impacts between concrete bridges and soil-steel composite bridges.

Point 3: L 73: bridges were proposed by [34] and [35]. → name the authors and then cite them. [34] and [35] are reference numbers not the authors.

Response 3: Thank you for the suggestion. In the revised manuscript, we have listed the authors according to your suggestion, please see below.

The methods to assess the sustainability of bridges were proposed by Arya et al. [30] and Yadollahi et al. [31].

Point 4: Page 2: summarize the main points in a table.

Response 4: Thank you for the suggestion.

In Page 2 of the manuscript, this part expounded the research of civil engineering sustainability from the aspects of buildings, bridges, roads and materials. Then the importance of applying bibliometrics and social network analysis in the research of civil engineering sustainability was presented.

In order to make the main line of this research much clearer, the definition, application and general analysis of the two methods were added in the revised manuscript, please see below.

Through the review of current research on sustainability of civil engineering, it can be found that existing research has covered the whole fields of civil engineering. However, the existing articles of literature review represent that the reviewers could only focus on part research area due to the limitations of the existing methods, which makes it difficult for researchers to grasp the overall view and link their research with the whole trend of civil engineering sustainability research, resulting in repeat and lag research. While, the research of the articles in Environmental Impact Assessment Review [46], sustainable decision-making [47] and green building [48] proved that the bibliometric analysis and the social network analysis (SNA) are effective methods to comprehensively analyze the existing research by constructing the literature relationship map from the perspective of the basic statistics and mutual relations of the literature research contents even if there are a lot of relevant articles in this research filed.

Bibliometrics is a quantitative analysis method of literature by applying mathematical and statistical methods [49], it can extract valuable information from massive literature data by statistical analysis of research fields, publications, countries, institutions, etc., and provide crucial support for subsequent research. As to the SNA, it is a quantitative and visual analysis method developed by sociologists based on mathematics and graph theory which has been widely used in engineering construction [50], international trade [51] and knowledge management [52]. The SNA can use centrality analysis to study the nodes and connections of networks from a new perspective through the establishment of actors, ties and boundaries [53].

Geng et al. [54] analyzed the articles of building life cycle assessment from 2000 to 2014 based on bibliometric analysis. The research of Yin et al. [55] shows that bibliometric analysis and knowledge network could effectively discuss the literature about building information modelling (BIM) and off-site construction. Cabeza et al. [56] carried out comparative analysis between the database: Web of Science (WoS) and Scopus in the energy efficiency and climate impacts of buildings through bibliometric. Oraee et al. [57] studied BIM-based Construction Networks as an example to quantitatively evaluate different research contents by the network analysis and bibliometric. Through the scientometric study of 501 off-site construction documents, Hosseini et al. [58] found the complement of existing research and indicated the importance of operation and management. Li et al. [59] made a bibliometric analysis of 1,874 BIM articles and determined the corresponding crucial research areas and clusters. Ganbat et al. [60] concentrated on the BIM risk management by reviewing 526 articles based on a database, Citespace, with the bibliometric method. Udomsap and Hallinger [61] selected 2,877 Scopus-indexed documents to study the hotspots of sustainable construction through bibliometric review and network analysis. In recent years, bibliometrics was employed to analyze the evolution of prefabricated building policies by Wang et al. [62].

Through the analysis of relevant research, it is found that the bibliometric analysis has been applied in the literature research of civil engineering especially in the research of BIM. Due to the development of library management, bibliometric analysis has been integrated into different databases such as WoS and Scopus. This phenomenon makes it possible to carry out important statistics and citation analysis in civil engineering literature research, and conduct further study through the Citespace.

However, the SNA is still in the development stage in the analysis of civil engineering literature, and current applications mainly based on three different softwares: (1) The direct visualization analysis method of articles in different databases based on VOSviewer; (2) Literature data analysis method based on traditional network analysis tools such as the Pajek; (3) Network visualization analysis of literature based on Gephi (An open source free cross-platform network analysis software based on java virtual machine) and text-processing. After comparing the three methods, it is found that Gephi has been widely adopted due to its advantages of visualization and data analysis.

Therefore, this paper will conduct an in-depth quantitative analysis in the research of civil engineering sustainability from 2015 to 2019 based on the SNA (applying Gephi) and bibliometric analysis. According to the statistical result of articles, this paper firstly discusses the research directions, source publications, source countries and institutions. Then two network models of research contents and teams are constructed separately based on the co-occurrence frequency relationship among different keywords and authors. The quantitative results of the influences about different research contents and researchers are calculated through the SNA. At last, the research hot points, methods, deficiencies and the relationship among authors of existing research are presented.

Point 5: Page 3: Add a flow chart to show your study’s procedure.

Response 5: Thank you for the comment and suggestion.

In the revised manuscript, the main process of this research is described in Figure 1, and the flow of bibliometric analysis and social network analysis is elaborated, please see below.

The purpose of this study is to conduct a comprehensive analysis of civil engineering sustainability research to identify the hotspots and shortcomings of existing research, providing reference for future needs and directions through integration of international literature published during the past five years (2015-2019). The research process mainly includes three parts: (1) determination of the basic data source of published literature; (2) establishment and preliminary statistics of the network model of the published articles; (3) systematic analysis of the established network. Figure 1 shows the main roadmap of the analysis process of the paper.

Figure 1. Analyzing roadmap of civil engineering sustainability research based on the SNA.

In the process shown in Figure 1, some information needed for bibliometrics can be preliminarily obtained through the export of SCI and SSCI journal literature data related to civil engineering sustainability. After artificial adjustment and research of existing data, the bibliometric analysis can be carried out to determine the statistical results of research fields, publications, source countries and institutions. According to the preliminary statistical database, the co-occurrence relationship matrices of keywords and authors can be constructed based on the common occurrence frequency of keywords and authors in different literature. Then this research imports the above matrices into Gephi to construct research network and cooperation network to calculate the centrality, eigenvector centrality and betweenness centrality of the networks.

Point 6: L 104: literature about BIM (building information model) and OSC (off-site construction). → for acronyms, first you should mention the full form and then abbreviate it.

Response 6: Thank you for the reminder. In the revised manuscript, we modified the expression, please see below.

The research of Yin et al. [55] shows that bibliometric analysis and knowledge network could effectively discuss the literature about building information modelling (BIM) and off-site construction.

Point 7: L 200: Institutions that published → use past tense

Response 7: Thank you for the reminder. In the revised manuscript, this expression has been modified, please see below.

Figure 4. Institutions that published over 1% of the selected articles.

Point 8: L 231: Font size is very small in the figure

Response 8: Thank you for the reminder.

In the revised manuscript, the figure has been changed. In order to make the calculated results more intuitive, the size of the node names in the figure is determined based on the calculated results of degree. Therefore, there is no excessive adjustment in the relative size of node names, the clarity of the figure the focus.

Figure 5. The social network model of civil engineering sustainability（Gephi, Nodes=7,315, Edges=225,741）

Point 9: L 251: Font size is very small in the figure

Response 9: Thank you for the reminder. In the revised manuscript, the figure has been changed, please see below.

Figure 6. The network model of civil engineering sustainability with frequency of keywords more than or equal to 20（Gephi, Nodes=151, Edges=11,882）

Point 10: L 255: The sentence is incomplete 

Response 10: Thank you for the suggestion. In the revised manuscript, the sentence has been corrected, please see below.

The SNA of the authors can clearly reveal the cooperation relationship among authors, building a concrete data foundation for the subsequent research work.

Point 11: L 267: Font size is very small in the figure

Response 11: Thank you for the reminder. In the revised manuscript, the figure has been changed, please see below.

Figure 7. The cooperation network model of civil engineering sustainability from 2015 to 2019（Gephi, Nodes=145, Edges=574）

Point 12: L 335: ranking 32th → ranking 32^nd.

Response 12: Thank you for the suggestion. In the revised manuscript, this expression been changed, please see below.

The eigenvector centrality result of China is 0.047 ranking 32^nd.

Point 13: L 376: Please use a different term than “are the most important authors”

Response 13: Thank you for the suggestion. In the revised manuscript, this term has been changed by “influential” in line 422, please see below.

R.Y.Jin and J.Zuo are the most influential authors in connecting different groups.

Point 14: L 390: Incomplete sentence.

Response 14: Thank you for the reminder. In the revised manuscript, the sentence has been changed, please see below.

Today civil engineering is facing the severe challenge of sustainable development.

Point 15: L 420: Four authors comes → Four authors come 

Response 15: Thank you for the reminder. In the revised manuscript, the sentence has been corrected, please see below.

Among the 10 authors in the center, there are four authors come from the countries between the Tropics of Cancer and Capricorn.

Point 16: L 427: Use past tense.

Response 16: Thank you for the reminder. In the revised manuscript, the sentence has been fixed, please see below.

In the betweenness analysis, the important authors who played the role of communication among different research teams were identified.

Point 17: L 430: Use past tense throughout the conclusion section.

Response 17: Thank you for the reminder. In the revised manuscript, the conclusion section has been changed, please see below.

This paper analyzed 1,846 published articles on the theme of civil engineering sustainability based on the bibliometric and SNA. Through the study of the keyword co-occurrence and research teams, the research cores, research contents, source publications, countries and institutions of existing civil engineering sustainability research were analyzed. The quantitative assessment of influences on different contents was carried out. The main conclusions were as follows. (1)The existing research of civil engineering sustainability took engineering as the main subject to study through technology, and the coupling of environmental science and engineering technology was sufficient; (2)The main contents were to conduct technological innovations and evaluations of environmental impacts on construction technology, energy consumption, material preparation and design; (3)The existing researches mainly focused on the environmental dimension of sustainability, but lack sufficient attention to the economic and social dimensions; (4)In the research object, many researches took the engineering cases of China as examples, making China and Hong Kong appear as keywords in many articles; (5)In the source publications, the average IF of journals is 4.19, 24.11% articles were published in the journals with IF being greater than 5. Journal of Cleaner Production and Sustainability are the two most frequently published journals; (6)In the source counties and institutions, USA and China are the counties with the largest number of relevant researches in the world, and the HKPU is the institution with the largest number of published articles; (7)In the researchers, Professor J.Zuo of the University of Adelaide is the researcher who published most articles in civil engineering sustainability, and researchers such as H.Y.Li, C.Mao, J.Wang, W.Y.Szeto are the bridges among different researchers or research groups.

From the analysis of this paper, we can recognize that the bibliometric and SNA are the effective methods to evaluate and quantify the researches and examine publication characteristics such as research contents and teams, institutions and journals. The two methods provide a quantitative perspective to understand the characteristics associated with civil engineering sustainability research. Based on these two methods, the hotspot of research and the main hub of research teams were identified, presenting useful references for researchers to select the field and direction of future research about civil engineering sustainability. Moreover, the relationship of different research teams was revealed. This could be a direct basis for communications among researchers.

Point 18: L 480: The acknowledgement section is left as was in the template.

Response 18: Thank you for the reminder. In the revised manuscript, the acknowledgement has been deleted.

Author Response File: Author Response.pdf

Reviewer 3 Report

This study deals with bibliometric and social network analysis of civil engineering sustainability research from 2015 to 4 2019. The quality and quantity of the work are excellent. The analysis is comprehensive. It certainly has good contribution to the civil engineering research. The paper is recommended to be accepted by the journal 

Author Response

Response to Reviewer 3 Comments

Point 1: This study deals with bibliometric and social network analysis of civil engineering sustainability research from 2015 to 4 2019. The quality and quantity of the work are excellent. The analysis is comprehensive. It certainly has good contribution to the civil engineering research. The paper is recommended to be accepted by the journal

Response 1: Thank you for the approval.

Round 2

Reviewer 2 Report

The manuscript can be accepted now.

Author Response

Response to Reviewer 2 Comments

Point 1: The manuscript can be accepted now.

Response 1: Thank you for the approval.