This paper describes recent advances in the effect of soil creep on the time-dependent deformation of deep braced excavation. The effect of soil creep is generally investigated using the observational method and the plain-strain numerical simulation method. The observational method is more applicable for deep braced excavations in soft clays constructed using the top-down method. The plain-strain numerical simulation method can be conveniently used for parametric analysis, but it is unable to capture the spatial characteristics of soil creep effect on lateral wall deflections and ground movements. The additional lateral wall deflections and ground movements that are generated due to the soil creep effect can account for as large as 30% of the total displacements, which highlights the importance of considering the effect of soil creep in deep braced excavations through soft clays. The magnitude of the displacements due to soil creep depends on various factors, such as excavation depth, elapsed period, unsupported length, and strut stiffness. Parametric analyses have indicated several effective measures that can be taken in practice to mitigate the detrimental effect of soil creep on the deformation of deep braced excavation. Based on the literature review, potential directions of the related future research work are discussed. This paper should be beneficial for both researchers and engineers focusing on mitigating the adverse effect of soil creep on the stability of deep braced excavations.

Reviewing literature revealed that the studies on the bearing characteristics of pile foundations mainly focuses on clay, ordinary sand, loess, saline soil, and other areas. However, few studies on the bearing characteristics of the pile foundation in calcareous sand were conducted. Besides, existing traditional studies ignored the variation of soil compression modulus with depth, and the effect of void ratio on the transverse bearing characteristics of the pile foundation in a calcareous sand area were not well understood. In response of these problems, this study conducted a theoretical investigation on the transverse bearing characteristics of the pile foundation in a calcareous sand area. The transverse bearing characteristics of the pile foundation were derived based on the Pasternak foundation model and the Winkler foundation model, incorporating the heterogeneous distribution of compressive modulus with buried depth. The calculation results of the Pasternak foundation model are closer to the observed results than the Winkler foundation model. Therefore, the following research on the transverse bearing characteristics of the pile foundation in the calcareous sand area adopts the Pasternak foundation model. Then, the effects of the pile length, pile diameter, pile elastic modulus, horizontal load, bending moment, and void ratio on the transverse bearing characteristics of the pile foundation in a calcareous sand area were thoroughly analyzed. Furthermore, the difference between the transverse bearing characteristics of the pile foundation in a calcareous sand area and a quartz sand area was discussed. Results show that the horizontal displacement of the pile top in a calcareous sand area is greater than the quartz sand area under the same conditions.

The existence of flaws in brittle rocks or rock‐like materials has an obvious influence on the material mechanical properties and cracking behavior of civil engineering projects. In this work, the two‐dimensional particle flow code PFC^2D was used to study the deformation and strength properties, failure processes, and acoustic emission (AE) characteristics of mudstone with a single preexisting flaw. First, the procedure to construct a parallel bond model is introduced. The Weibull distribution is used to reflect the mechanical heterogeneity of rocks. Then, the microscopic parameters used in PFC^2D are calibrated to the macroproperties of mudstone obtained from laboratory tests under the uniaxial compression. The results indicate that the increases of the flaw inclination lead to the increasing uniaxial compressive strength and elastic modulus. In terms of microcrack evolution, the initiation, propagation, and coalescence of microcracks are closely related to the force chain. Specifically, an “X” shaped tension force chain concentrated area around the preexisting flaw is founded, which is the most prone area for microcracks to initiate. With an increase in flaw inclination, the b value of AE also shows an increasing trend. By incorporating the AE event numbers into a damage variable, this paper derives a constitutive model, which is verified by numerical results on brittle rocks with a single preexisting flaw under uniaxial compression.

Highway tunnel plays an increasingly prominent role in the development of high‐grade highway traffic in mountainous countries or regions. Therefore, it is necessary to explore the deformation characteristics of the surrounding rock of a six‐lane multiarch tunnel under different excavation conditions. Using the three‐dimensional indoor model test and finite element analysis, this paper studies the dynamic mechanical behavior of a six‐lane construction, reveals the whole process of the surrounding rock deformation process of class II surrounding rock under different excavation conditions, and puts forward the best construction and excavation method. The results show that the maximum displacement rate of excavation scheme III is the largest, and the maximum displacement rate of excavation scheme I is basically the same as that of excavation scheme II. Therefore, in terms of controlling the displacement rate of the surrounding rock, the effect of excavation scheme I is basically the same as that of excavation scheme II, while that of excavation scheme III is poor. In terms of construction technology, scheme II is simpler than scheme I and can ensure the integrity of the secondary lining. Therefore, in class II surrounding rock of the supporting project, it is recommended to adopt scheme II for construction.

Rapid connectors for shield tunnels represent a critical advancement in underground engineering construction. This study proposes a novel auto-lock connector, detailing its structure and working principle. The flexural behavior of the auto-lock joint is investigated through theoretical analysis and numerical simulation, with a comprehensive evaluation of influencing factors. The results indicate that joint opening increases with reduced axial force, peaking at 24.1 mm under negative bending under a 100 kN axial load. The ultimate bending moment demonstrates a nonlinear variation with axial force. At low axial forces, increasing material strength or dimensions enhances joint flexural capacity, with more pronounced improvements under lower loads. This research establishes a theoretical foundation for the practical application of auto-lock connectors.