This study investigated the thermal environment and comfort in elevated subway stations in Wuhan, determined passenger thermal comfort ranges, and examined the impact of station architectural forms on passenger comfort during typical summer days at five representative stations. The research combined instrumental measurements with subjective surveys. Linear fits were applied to the standard effective temperature (SET*) and mean thermal sensation vote (MTS) at two stations, and these were compared with the predicted thermal sensation (PTS) to determine passengers' thermal sensation ranges. The results indicated that the stations tended to fail to meet the requirements of the "Code for design code (GB 501572013)". Additionally, indoor air temperatures were frequently too high, relative humidity largely met the standard, and air velocities in most stations were low. Survey data suggest that station design significantly affects passenger thermal comfort, revealing a preference for open platforms during summer. Moreover, the PTS curve remained consistently higher than the SET*MTS curve, indicating that passengers' summer thermal adaptations exceeded expectations. Finally, common shading, ventilation, and thermal environment improvement measures for regions with hot summers and cold winters were proposed alongside theoretical insights for enhancing thermal comfort and supporting green transitions in elevated subway stations in Wuhan.

To predict the vibration response of buildings along subway lines quickly and reasonably, a building structural system is decomposed into two parts, namely, a propagation structure and a response structure, based on the theory of mechanical mobility. The bearing structure is assumed to be a beam element model, and the slab structure is considered a plate element model. The mobility formula and the corresponding matrix expressions for each unit system are derived, and a traininduced structural vibration response model is constructed. The reliability and accuracy of the model are validated through onsite testing, showing that the predicted structural responses align well with measured vibrations in both time and frequency domains. In the frequency domain, the maximum error of the center frequencies of each 1/3 octave band does not exceed 5 dB, indicating that the proposed traininduced structural vibration response model can quickly and effectively predict the structural vibration response and that the outcomes can provide theoretical support for vibration prediction along subway lines.

This study examines the impact of shield tunneling excavation speed and slurry solidification time on the buoyancy of tunnel segments, focusing on the section between Tongyuan Road Station and Xinggang Street Station on Suzhou Metro Line 5. A threedimensional finite element model of shield tunnel segments was developed using Winkler elastic foundation beams, considering the dynamic and static buoyancy effects generated by synchronous and secondary grouting on the pipe segments. The analysis assessed how excavation speed and grouting solidification time influence the uplift and misalignment of the segments. Results showed that both uplift and misalignment increased with higher tunneling speeds. The upward floating problem mainly occurs at the bottom of the pipe segment in the nonsolidified section of the slurry, whereas the misalignment mainly occurs at the junction between the nonsolidified section and the shield tail section, as well as between the nonsolidified section and the solidified section of the slurry. To avoid floating and misalignment of the pipe segments from exceeding the specification requirements, the excavation speed of the shield machine should not exceed 10 rings per day. Furthermore, it was observed that as the solidification time of the slurry increased, the amount of floating and misalignment of the tunnel segments gradually increased. Therefore, the use of a fastsetting and early strength dual liquid slurry is beneficial for controlling the floating of shield tunnels.

In response to the increasing speed and strict requirements for bridge smoothness in the design of railelevated bridges, this study is based on the design of the elevated bridge of Beijing Metro Line 22 at a speed of 160 km/h. A new type of adjustable height device is developed and designed based on a lowmeltingpoint alloy as the height adjustment medium. A series of experimental studies are conducted, including the structural design of the device, indoor temperature and pressure tests, fullscale pressure adjustment performance tests of the compression shear machine, and onsite beam erection tests. The findings indicate that the new adjustable height device enables stepless bidirectional height adjustment with a rapid adjustment speed, completing height changes within 30 s. The device achieves millimeterlevel accuracy, and the alloy demonstrates excellent stepless adjustment performance and compression stability once cooled and solidified. The accuracy and stability of this adjustable height device not only ensure the smoothness of elevated bridge beams but also offer valuable guidance for engineering applications, such as replacing deteriorated bearings and adjusting for differential settlement in bridges.

When a shortcircuit fault occurs between the positive pole of a highvoltage DC circuit for a train and its carbody inside the station in a straddle seat monorail DC traction system, this causes the carbody grounding relay (GR) of all trains inside the station to actuate and the circuit breakers of the train to trip. Meanwhile, this also triggers multiple 64D grounding protection actions and trips the circuit breaker of the DC feeder. The fault results in a loss of power to the DC traction system. It is necessary to identify the faulty train and restore the normal power supply of the DC traction system as soon as possible to reduce the impact of the accident. First, the study analyzed characteristic differences in the amplitude of the grounding current and negative receiving electricity current for a faulty train compared to a normal train when a shortcircuit occurred between the positive circuit and the carbody based on the equivalence model of the DC traction bipolar power supply system for straddle monorail transportation. Second, an identification method for a faulty train is proposed based on a comparison of the grounding current and negative current amplitude. The identification procedure is activated when the grounding current exceeds a predetermined threshold. If the grounding current amplitude is greater than the negative current, the train is identified as faulty; otherwise, it is considered to be in a normal state. The accuracy and effectiveness of this method were validated through MATLAB simulations and field tests. The proposed approach is simple, practical, and highly reliable, providing a strong safeguard for the safe operation of straddleseat monorail systems.

To minimize disturbances to an existing metro station during shield tunneling in a waterrich soft stratum, this study focuses on the construction of a Ttype transfer station where shield tunneling passes through an operational station. The study examines the cutter configuration and tunneling parameters for shield tunneling through a diaphragm wall without glass fiber reinforcement using theoretical analysis and field measurements. Key risk control measures for shield tunneling through the operational station are also proposed. The results indicate that the shield can safely cut through the diaphragm wall by using highstrength shell cutters with varying heights, reducing the tunneling speed and shield thrust, and increasing the cutter head torque. Disturbances to the station floor can be reduced by considering the interaction force between the station floor and the surrounding stratum as an additional load during the underpass construction. Setting the chamber pressure at 1.2 times the static soil pressure at the shield's center further minimizes floor disturbance. Effective settlement control of the existing structure is achieved by filling the gap between the shield shell and the surrounding stratum with clay shock and using a combination of synchronous grouting, secondary grouting, and radial grouting to fill gaps behind the segments. The primary deformation caused by tunneling beneath the operational station is settlement, while shield cutting through the diaphragm wall leads mainly to horizontal displacement, accounting for over 75% of the total horizontal movement.

To address the challenges of high risk and extended construction periods associated with conventional methods for building longdistance connection channels, this study introduces a mechanical method in the composite formations of South China for the first time. Research focused on the overall project plan, selection of construction methods, equipment choices, and segment structure design, which led to the successful implementation of the project based on these findings. The following conclusions can be drawn: the mechanical method of connecting channels can solve engineering problems with long distances, large angles, and large inclinations and is applicable to composite formations in South China; it is feasible to change the assembly method of pipe segments from radial insertion to longitudinal insertion followed by radial insertion, by modifying the pipe segment design scheme.

To address issues related to the size effect of deep circular shaft excavation for rail transit, this study analyzes the stress and deformation characteristics of a circular excavation enclosure structure using the foundation pit project of the ShenzhenDaya Bay Intercity circular working shaft as a case study. The loadstructure method is employed to systematically examine these characteristics under various diameter conditions. The study compares the calculation results from both a 3D spatial structure model and a 2D elastic foundation beam model, discussing the impact of excavation size on the performance of the circular enclosure structure. The findings reveal that the circular diaphragm wall behaves as a quasicircular structure, generating a vertical bending moment due to soil and water pressure, which indicates a multidirectional stress state. It is feasible to utilize a simplified 2D equivalent model for designing a circularfoundation pitretaining structure, as its calculation results are more conservative than those of the 3D model. Furthermore, the spatial dimension significantly influences the performance of the circular enclosure structure, with noticeable circumferential effects observed when the diameter of the deep circular working shaft is less than 30 m.

This paper proposes a combined support system comprising retaining piles, tensioned anchor rods, and inclined anchor cables with grouting to solve the problems associated with constructing supporting structures for deep excavations near obstacles on one side. The study utilized Midas software for modeling, and singlefactor optimization analysis schemes were designed considering four aspects: spacing and diameter of tensioned anchor rods and number and length of segments for inclined tensioned anchor cables. The rationality of this scheme was validated using engineering examples. The results showed a match between the simulated trends of the horizontal and vertical displacements of the slopeprotection pile tops and the monitoring results. The vertical displacement exhibited a parabolic trend, and the horizontal displacement exhibited an arched shape. The maximum horizontal displacement of the pile tops decreased as the spacing of the tensioned anchor rods decreased and increased as their diameters and the number and length of segments of inclined tensioned anchor cables decreased. During construction, the deformation of subway ancillary structures was wellcontrolled and significantly less than that of the adjacent deep excavation. The top settlement showed a fluctuating upward trend, whereas the deep horizontal displacement had a middlehigh and endlow pattern at different excavation stages. As the excavation depth increased, the subway structures' maximum horizontal deformation shifted downward along the shaft wall.

This study explores the applicability of oblique bolt joints in smalldiameter shield tunnel beam melting (TBM) tunnels, clarifying their mechanical properties and damage mechanisms. A segment structure with an external diameter of 6.2 m and a thickness of 350 mm was utilized as a prototype for conducting bending performance tests on steel fiber concrete segments with oblique bolted joints under four different horizontal axial force conditions. The analysis focused on the deformation characteristics and flexural performance of the segment joints across varying axial force levels, as well as the failure processes and mechanical properties under failure conditions. The results showed that the higher the axial force on the segment joints, the higher the joint stiffness, requiring larger bending moments to open the joint. In other words, the joint axial force can be actively increased by increasing the bolt preload or by applying annular prestressing to improve the joint stiffness. Compression of the sealing gasket under joint axial force results in stress concentrations within the sealing groove. Therefore, selecting an appropriate sealing gasket or optimizing the sealing groove structure is essential in the design process. The study also found that enhancing the compressive strength of the top concrete and reducing the insertion angle of the oblique bolt significantly improve joint bearing capacity. These findings provide valuable guidance for the design of segment joints.