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In shield tunneling projects, human, shield machine and underground environment are tightly coupled and interacted. Accidents often occur under dysfunctional interactions among them. Therefore, this paper aims to develop a multi-agent based safety computational experiment system (SCES) and use it to identify the main influential factors of various aspects of human, shield machine and underground environment.

The methods mainly comprised computational experiments and multi-agent technologies. First, a safety model with human-machine-environment interaction consideration is developed through the multi-agent technologies. On this basis, SCES is implemented. Then computational experiments are designed and performed on SCES for analyzing safety performance and identifying the main influential factors.

The main influential factors of two common accidents are identified. For surface settlement, the main influential factors are ranked as experience, soil density, soil cohesion, screw conveyor speed and thrust force in descending order of influence levels; for mud cake on cutter, they are ranked as soil cohesion, experience, cutter speed and screw conveyor speed. These results are consistent with intuition and previous studies and demonstrate the applicability of SCES.

The proposed SCES provides comprehensive risk factor identification for shield tunneling projects and also insights to support informed decisions for safety management.

A safety model with human-machine-environment interaction consideration is developed and computational experiments are used to analyze the safety performance. The novel method and model could contribute to system-based safety research and promote systematic understanding of the safety performance of shield tunneling projects.

The shield tunnels closely constructed near the foundations have an inevitable influence on the structures, even results in the large settlement or uplift of the structures.

The comparison of structural deformation of three different foundations is presented based on the field monitoring data.

Shield tunnelling parameters vary for the different types of foundations. For the long pile foundations, the recommended speed is 3 to 4 cm/min, the grouting pressure is about 0.3 MPa and the grouting rate ranges from 150 to 180.

The study based on the field monitoring data is rarely reported, especially the topic about the structural deformation of different types of the foundations.

Under the repeated action of the construction load, opening deformation and disturbed deformation occurred at the precast box culvert joints of the shield tunnel. The objective of this paper is to investigate the effect of construction vehicle loading on the mechanical deformation characteristics of the internal structure of a large-diameter shield tunnel during the entire construction period.

The structural response of the prefabricated internal structure under heavy construction vehicle loads at four different construction stages (prefabricated box culvert installation, curved lining cast-in-place, lane slab installation and pavement structure casting) was analyzed through field tests and ABAQUS (finite element analysis software) numerical simulation.

Heavy construction vehicles can cause significant mechanical impacts on the internal structure, as the construction phase progresses, the integrity of the internal structure with the tunnel section increases. The vertical and horizontal deformation of the internal structure is significantly reduced, and the overall stress level of the internal structure is reduced. The bolts connecting the precast box culvert have the maximum stress at the initial stage of construction, as the construction proceeds the stress distribution among the bolts gradually becomes uniform.

This study can provide a reference for the design model, theoretical analysis and construction technology of the internal structure during the construction of large-diameter tunnel projects.

On shield tunnel construction (STC) site, human error is widely recognized as essential to accident. It is necessary to explain which factors lead to human error and how these factors can influence human performance. Human reliability analysis supports such necessity through modeling the performance shaping factors (PSFs). The purpose of this paper is to establish and validate a PSF taxonomy for the STC context.

The approach taken in this study mainly consists of three steps. First, a description of the STC context is proposed through the analysis of the STC context. Second, the literature which stretch across the PSF methodologies, cognitive psychology and human factors of STC and other construction industries are reviewed to develop an initial set of PSFs. Finally, a final PSF set is modified and validated based on STC task analysis and STC accidents cases.

The PSF taxonomy constituted by 4 main components, 4 hierarchies and 85 PSFs is established for human behavior modeling and simulation under the STC context. Furthermore, by comparing and evaluating the performance of STC PSF and existing PSF studies, the proposed PSF taxonomy meets the requirement for qualitative and quantitative analysis.

The PSF taxonomy can provide a basis and support for human behavior modeling and simulation under the STC context. Integrating PSFs into a behavior simulation model provides a more realistic and integrated assessment of human error by manifesting the influence of each PSFs on the cognitive processes. The simulation results can suggest concrete points for the improvement of STC safety management.

This paper develops a taxonomy of PSFs that addresses the various unique influences of the STC context on human behaviors. The harsh underground working conditions and diverse resources of system information are identified as key characteristics of the STC context. Furthermore, the PSF taxonomy can be integrated into a human cognitive behavior model to predict the worker’s behavior on STC site in future work.

This paper aims to investigate the responses of single piles and pile groups due to tunneling-induced ground movements in a two-layered soil system. The analyses mainly focus on the additional single pile responses in terms of bending moment, lateral deflection, axial force, shaft resistance and pile settlement. Subsequently, a series of parametric studies were carried out to better understand the responses of single piles induced by tunneling. To give further understanding regarding the pile groups, a 2 × 2 pile group with two different pile head conditions, namely, free and capped, was considered.

Using the PLAXIS three-dimensional (3D) software, a full 3D numerical modeling is performed to investigate the effects of ground movements caused by tunneling on adjacent pile foundations. The numerical model was validated using centrifuge test data found in the literature. The relevance of the 3D model is also judged by comparison with the 2D plane strain model using the PLAXIS 2D code.

The numerical test results reveal that tunneling induces significant displacements and internal forces in nearby piles. The magnitude and distribution of internal forces depend mainly on the position of the pile toe relative to the tunnel depth and the distance between the pile and the vertical axis of the tunnel. As the volume loss increases from 1% to 3%, the apparent loss of pile capacity increases from 11% to 20%. By increasing the pile length from 0.5 to 1.5 times, the tunnel depth, the maximum pile settlement and lateral deflection decrease by about 63% and 18%, respectively. On the other hand, the maximum bending moment and axial load increase by about 7 and 13 times, respectively. When the pile is located at a distance of 2.5 times the tunnel diameter (Dt), the additional pile responses become insignificant. It was found that an increase in tunnel depth from 1.5Dt to 2.5Dt (with a pile length of 3Dt) increases the maximum lateral deflection by about 420%. Regarding the interaction between tunneling and group of piles, a positive group effect was observed with a significant reduction of the internal forces in rear piles. The maximum bending moment of the front piles was found to be higher than that of the rear piles by about 47%.

Soil is a complex material that shows differently in primary loading, unloading and reloading with stress-dependent stiffness. This general behavior was not possibly being accounted for in simple elastic perfectly plastic Mohr–Coulomb model which is often used to predict the behavior of soils. Thus, in the present study, the more advanced hardening soil model with small-strain stiffness (HSsmall) is used to model the non-linear stress–strain soil behavior. Moreover, unlike previous studies THAT are usually based on the assumption that the soil is homogeneous and using numerical methods by decoupled loadings under plane strain conditions; in this study, the pile responses have been exhaustively investigated in a two-layered soil system using a fully coupled 3D numerical analysis that takes into account the real interactions between tunneling and pile foundations. The paper presents a distinctive set of findings and insights that provide valuable guidance for the design and construction of shield tunnels passing through pile foundations.

This paper aims to analyse the effect of soft soil grouting on the deformation of the closed shield tunnel with the measured data.

Combining the measured data of vertical, horizontal and convergence deformation of the adjacent tunnel during the grouting construction in foundation pit engineering, the influence of grouting on metro tunnel in soft soil area is analyzed.

The researches indicate that early grouting has the main effect on the horizontal displacement of the tunnel; Due to the disturbing effect of the uninterrupted grouting construction on the soil and the transfer pressure of the rheological soil to the bottom of the tunnel, the tunnel is obviously lifted; And the convergence deformation of the tunnel increases caused by the overburden pressure in the vertical direction, so that the tunnel appears the phenomenon of staggered seam, large opening of bolted joint, damaged segment even leakage of water.

The study based on the field monitoring data is rarely reported, especially the topic about inadvertent grouting in soft soil area is likely to cause severe deformation of adjacent metro tunnel.

Prefabricated technology is gradually being applied to the construction of subway stations due to its characteristic of mechanization. However, the prefabricated subway station in China is in the initial stage of development, which is prone to construction safety issues. This study aims to evaluate the construction safety risks of prefabricated subway stations in China and formulate corresponding countermeasures to ensure construction safety.

A construction safety risk evaluation index system for the prefabricated subway station was established through literature research and the Delphi method. Furthermore, based on the structure entropy weight method, matter-element theory and evidence theory, a hybrid evaluation model is developed to evaluate the construction safety risks of prefabricated subway stations. The basic probability assignment (BPA) function is obtained using the matter-element theory, the index weight is calculated using the structure entropy weight method to modify the BPA function and the risk evaluation level is determined using the evidence theory. Finally, the reliability and applicability of the evaluation model are verified with a case study of a prefabricated subway station project in China.

The results indicate that the level of construction safety risks in the prefabricated subway station project is relatively low. Man risk, machine risk and method risk are the key factors affecting the overall risk of the project. The evaluation results of the first-level indexes are discussed, and targeted countermeasures are proposed. Therefore, management personnel can deeply understand the construction safety risks of prefabricated subway stations.

This research fills the research gap in the field of construction safety risk assessment of prefabricated subway stations. The methods for construction safety risk assessment are summarized to establish a reliable hybrid evaluation model, laying the foundation for future research. Moreover, the construction safety risk evaluation index system for prefabricated subway stations is proposed, which can be adopted to guide construction safety management.

The image of the construction industry in China, as in many other countries, is tarnished by its poor safety record. With the rapid development of subway systems in Chinese urban areas, construction workers are being exposed to new risks which are poorly understood and managed. Subway construction projects are large scale and scattered over many construction sites, and involve numerous stakeholders and sophisticated technologies in challenging underground environments. Accident rates are high and have significant economic and social consequences for the firms and people involved. Addressing the gap in research about the safety risk in these projects, the purpose of this paper is to advance understanding of the factors influencing the safety of Chinese subway construction projects with the overall objective of reducing accident rates.

A survey was conducted with 399 subway construction professionals across five stakeholder groups. Follow-up interviews were also conducted with five experienced experts in safety management on subway projects to validate the results.

It was found that the eight most critical factors perceived by stakeholders to influence safety risks on Chinese subway projects are: project management team; contractor-related factors; site underground environment; safety protection during the use of machines; safety management investment; site construction monitoring and measurement; hazard identification and communication; and use of machines in all stages. This indicates that in allocating limited project resources to improve the safety of subway projects, managers should focus on: developing safety knowledge and positive attitudes in leadership teams; formulating effective risk management systems to identify, assess, mitigate, measure and monitor safety risks on site; improving communications with stakeholders about these risks and effectively managing plant, equipment and machinery.

This research contributes a new multi-stakeholder perspective to the lack of safety research in Chinese subway construction projects. The research findings provide important new insights for policymakers and managers in improving safety outcomes on these major projects, producing potentially significant social and economic benefits for society and the construction industry.

The purpose of this study is to investigate the effect of presence of buried flexible pipe on the bearing capacity of shallow footing. First, a model study is performed where shallow footing model is tested for its load settlement behavior, with and without the existence of buried PVC pipe lying vertically below the base of the footing.

The experimental set-up consisted of a steel box filled with sand at two different relative density values [RD = 50 per cent (medium dense) and RD = 80 per cent (dense sand)] and vertical load was applied on the model footing through hydraulic jack and reaction frame arrangement connected with a proving ring. Test results are verified numerically using commercially available finite element code PLAXIS 2D. With due verification, a parametric study has been conducted, numerically, by varying the range of input parameters, such as unit weight, angle of internal friction, diameter of buried conduit and the Elastic modulus of the soil to assess the pre cent reduction in the capacity of the foundation soil because of the presence of underlying buried flexible pipe.

Results show that for each footing, there exists a critical depth below which the presence of the buried conduit has negligible influence on the footing performance. When the conduit is located above the critical depth, the bearing capacity of the footing varies with various factors, such as geotechnical parameters of soil and location and diameter of the buried conduit.

It is an original paper performed to assess the presence of buried flexible pipe on the bearing capacity of the shallow footing.

When integrating smart elements offered by emergent technologies, libraries are facing the challenges of technological renovation and maintaining their operation using emerging technology. Given the importance of smart library, new technologies are needed in building new libraries or renovation of existing libraries. The purpose of this paper is to propose a risk warning system for library construction or renovation in the aspect of risk management.

The proposed Internet of Things (IoT)-based system consists of sensors that automatically monitor the status of materials, equipment and construction activities in real time. AI techniques including case-based reasoning and fuzzy sets are applied.

The proposed system can easily track material flow and visualize construction processes. The experiment shows that the proposed system can effectively detect, monitor and manage risks in construction projects including library construction.

Compared with existing risk warning systems, the proposed IoT-based system requires less data for making dynamic predictions. The proposed system can be applied to new builds and renovation of libraries.