The lining rings of a shield tunnel are connected by steel bolts, which play an important role in longitudinal structural deformation during long-term operation. In recent decades, there have been increasing numbers of tunnel-crossing projects. In order to better understand the impact of undercrossing excavations on existing tunnels and to provide a quick and effective tool for evaluating the behaviors of existing tunnels before construction, a simplified analytical method is proposed. In the proposed model, a tunnel was simplified into a series of short beams connected by shear, tensile, and compressive springs, and the Pasternak two-parameter foundation model was used to describe the tunnel–soil interaction. The tunnel model not only considers the shear effect between the linings but also the rotation effect of the lining ring. The field data from two cases were used to compare with the calculated results, and the predictions were found to be in good agreement with the measured data, thus verifying the effectiveness of the method.

As an effective way of completing technically complex buildings or large‐scale infrastructure projects, a joint venture contracting approach has recently been widely used in the construction industry. However, numerous unfavorable results can occur in practice when undertaking construction joint ventures (CJVs). The contribution of this paper is its exploration of the potential obstacles to CJV practices and identification of the root causes of failure. First, through a literature review, semistructured interviews, and a questionnaire survey, seventeen variables were identified; the top three obstacle variables were (1) inconsistent management styles, (2) incompatible organizational cultures, and (3) organizational policy differences. Second, four grouped factors were extracted: (1) unfair and noneffective management; (2) lack of communication, understanding, and mutual trust; (3) policy, management style, and organizational cultural differences; and (4) potential conflicts beyond the CJV partnership. Finally, several strategies were proposed. The research findings could not only contribute to knowledge of CJVs but also provide valuable insights into promoting broader, better applications of CJV projects and contributing to their success.

Steel formworks are widely used in prefabricated buildings thanks to their good characteristics. With the rapid development of engineering construction in China, steel formwork concrete structures, characterized by convenient construction, good seismic performance, and high strength, are expected to be more extensively applied in engineering practice. However, the bearing capacity of different forms of steel formwork concrete is still unclear. Two prefabricated columns with different internal diaphragm styles were set up for axial compression tests to investigate the performance of steel formwork columns. This study conducts monotonic static loading tests on six prefabricated steel tube column specimens and performs finite element analysis by taking steel tube thickness, rebar diameter, and internal diaphragm style as the influencing parameters. The results show that the prefabricated specimens can work in the test process, and the ultimate bearing capacity is consistent between the tests and numerical simulation. Moreover, the nephograms obtained from numerical simulation also conformed to the failure mode of the specimens in the test process. Therefore, the finite element model proposed in this study can accurately predict the stress performance of steel formwork concrete stub columns. These results offer guidance for future engineering practices.

Multiple unusual vibrations occurred in SEG Plaza from May 18 to 20, 2021. To investigate the causes of these vibrations, a rigidity compression wind tunnel test was applied to study the wind-induced response of the main structure, and acceleration sensitivity analysis was conducted with parameters such as wind speed, structural period and damping ratio included. Additionally, the mast vortex-induced resonance equivalent force of reaction in the bottom was exerted on the top of the structure to obtain the acceleration response of the main structure with mast. Based on the evaluation of the vibration response of the structure before and after considering the mast as per the current specifications, it is indicated that the base overturning moment of the structure is much smaller than the specification value excluding the factor of mast, and the acceleration response varies significantly with wind pressure, structural frequency and damping ratio, but the centroid acceleration and the angular acceleration meet the comfort requirements. This indicates that the wind load on the main structure is not the dominant cause of the structural vibration. With the mast taken into account, the acceleration response of the structure exceeds the limits of the comfort level to varying degrees. For a mast damping ratio of 0.3%, the maximum angular acceleration exceeds the H-90 limit and the comfort level is poor. These findings provide considerable evidence that the dominant cause of vibration in the SEG Plaza was the vortex resonance of the top mast inducing higher mode resonance in the main structure.