Shield tunneling construction technology is widely used in urban rail transit construction due to its advantages of high excavation efficiency and high safety. The large-diameter shield tunneling of intercity railways have long excavation distances and deep burial depths. During the construction process, strong and rich water as well as extremely fragmented strata may be encountered, which will lead to difficulties such as drainage failure, low construction efficiency, and slow ground reinforcement effect. This paper summarizes and generalizes the engineering difficulties and construction processes encountered by the earth pressure shield tunneling of an intercity project in Shenzhen successfully crossing extremely fractured and water rich rock formations with large burial depths. The construction measures for the large-diameter earth pressure balance shield tunneling machine crossing the surrounding rock areas with large burial depths and water rich fractures are obtained. This area with a burial depth of up to 80 meters and a length of about 150 meters. During the construction process, the shield tunneling machine frequently encountered jamming and gushing, making it extremely difficult to excavate. Various methods were tried, and finally, ground reinforcement was adopted, thick slurry assisted excavation was used, and a combination of drainage and blocking was used to successfully cross the three extreme conditions. Due to the long excavation distance, it is inevitable to carry out excavation operations and replace cutting tools. It is extremely difficult to replace cutting tools in such extreme formations. A combination of ground grouting and grouting in the tunnel to fill the silo was attempted, and finally, atmospheric pressure excavation and tool replacement were successfully achieved. The research content and shield tunneling measures in this article can provide guidance for shield tunneling construction under similar extreme conditions such as long-distance crossing of strong water rich and extremely fractured strata.

With the development of urban construction, when engineering construction is carried out in the central area of the city, different construction projects often affect each other and operational conflict occurs. The side wall of a foundation pit that has been excavated and constructed has become the new normal as the tunnel starting hole. This paper takes the formation of the starting hole door of the mining tunnel of the sidewall cut-off support pile of a foundation pit pile supporting system in Guangzhou as the background. The method of finite element numerical simulation and actual measured data comparison and analysis is used to study the influence of the instantaneous and subsequent construction of the pile supporting system on the stress and strain of the foundation pit support structure. The research results show that the moment of the foundation pit pile cut-off has a significant impact on the foundation pit support structure within a range of 1 times the hole diameter, especially the foundation pit support structure close to the hole opening. The stress-strain distribution in the subsequent foundation pit excavation process evenly allocates the impact of the pile cut-off construction on the local foundation pit support structure. The moment the foundation pit support pile is cut-off, the foundation pit support structure within the range of 1 times the hole diameter from the entrance of the pile cut-off, especially the foundation pit support structure close to the entrance of the pile cut-off shows obvious steep displacement change and stress concentration. The displacement and stress changes of the support structure outside the distance from the entrance of the pile cut-off are relatively small. As the foundation pit continues to be excavated, the foundation pit support structure outside the range of 1 times the hole diameter from the entrance of the pile cut-off gradually begins to share the impact of the pile cut-off on the foundation pit support structure, and the final displacement trend and internal force distribution of the foundation pit support structure show obvious structural integrity and spatial ductility.

With the rapid development of information technology, the survey and design industry is undergoing digital transformation, and Building Information Modeling (BIM) technology provides a 3D digital solution for the entire life cycle of engineering projects. Survey BIM achievements integrate data such as geological models, geographic information, and underground pipe networks, providing an accurate data foundation for engineering construction. However, their value has not been fully exploited in practical applications.Taking the Longhua District Maternal and Child Health Hospital Project in Shenzhen as the research object, this paper addresses the application bottlenecks of survey BIM achievements in the construction phase, such as software barriers and viewing convenience, and proposes a solution combining lightweight processing and mobile terminal query technology. Specifically, model lightweighting is achieved through triangulation-based geometric optimization and on-demand loading of attribute data, while operational fluency is enhanced by integrating visibility preprocessing and component reuse technologies. Based on the lightweight model, a mobile application is developed to realize real-time query of geological conditions, intelligent review of pipelines, and dynamic guidance for pile foundation construction.The research shows that this solution can effectively break through the limitations of traditional applications, improve the intelligent application level of survey BIM achievements in the construction phase, and provide efficient data support for engineering construction.

Accurate prediction of long-term settlements, particularly post-construction settlements, of soft clayey soil has also been a challenge in geotechnical engineering. Terzaghi's one dimensional consolidation theory does not consider soil creep, hence it fails to accurately predict the long-term settlement. There is currently no consensus on how to account for soil creep when calculating settlements of soft soil. Some scholars advocate that there is no need to consider the influnce of soil creep during the primary consolidation and there exists a unique relationship between the end-of-the-primary-consolidation (EOP) void ratio and vertical effective stress (Hypothesis A). While other scholars believe that soil creep does occur during and after primary consolidation, and the EOP void ratio depends on the primary consolidation duration (Hypothesis B). Recently, more and more scholars have proven the rationality of Hypothesis B, and settlement calculation methods based on Hypothesis B have also been adopted by Canadian and European codes. However, most codes of practice involving settlement calculations in China are still based on Hypothesis A. This paper selects Mesri's settlement/compression calculation model, Yin-Graham elastic viscoplastic model and Soft Soil Creep model, MIT-SR model, to compare and analyze their elaboration, theoretical framework and main formulas. We hope to take this opportunity to enlighten the thinking of geotechnical practitioners on the time effect and settlement calculation of soft soil. At the end of the paper, Yin's Simplified Hypothesis B method for settlement calculation is introduced along with its application, further demonstrating its validity.

Under the geological conditions influenced by the interaction between water-rich sand layers and the Pearl River system, seepage in the retaining structures of deep foundation pits adjacent to the river frequently occurs, leading to incidents such as ground collapse, pipeline subsidence, and fractures. These issues severely hinder project development progress and jeopardize the safety of the surrounding environment. This paper analyzes the causes of localized leakage in a deep excavation supported by secant pile walls under the water-rich sandy stratum conditions adjacent to the Pearl River in Tianhe District, Guangzhou, using practical case studies. Based on factors such as excavation depth and available working space at the top of the pit, a series of leakage control measures were implemented. These included vertical surface grouting, local excavation, inter-pile oblique grouting consolidation, steel plate sealing, enhanced shotcreting with mesh reinforcement, and rapid bottom sealing. These measures ensured the successful completion of the underground construction phase and can serve as an engineering reference for other similar projects.

Conducting shallow structure tomography in Hong Kong is of great significance for engineering construction, urban underground space utilization, and geological disaster prevention. In this study, we deployed a linear array of 48 node seismometers at a construction site in northern Hong Kong and collected ambient noise data for about 2 days. The effects of different stacking durations and stacking methods on the Noise Cross-correlation Function (NCF) were tested, indicating that the signal-to-noise ratio of NCF can be effectively improved by considering weighted methods during short-time stacking. We used the passive source-based Multi-channel Analysis of Surface Wave (MASW) method to extract the Rayleigh wave dispersion curve and inverted it to obtain the two-dimensional S-wave profile of the test site. Our results demonstrate that shallow S-wave tomography based on ambient noise data can quickly, safely and non-invasively constrain shallow structures, showing great potential for underground engineering applications.

Based on the dual-system theory, this study explores distinct categories of adolescent self-control and their relationship with smartphone addiction. A random sampling method was used to survey 2 203 middle school students on self-control and smartphone addiction. Latent profile analysis (LPA) was employed to classify self-control types and examine their associations with smartphone addiction. Adolescent self-control was categorized into three groups: Low Control-Low Impulse Group (6.49%): scored lowest on problem-solving, future time perspective, impulsivity, distractibility, and low delay of gratification;High Control-Low Impulse Group (40.22%): scored highest on problem-solving and future time perspective, with low impulsivity, distractibility, and delay issues; Moderate Control-High Impulse Group (53.29%): scored intermediately in problem-solving and future time perspective, but highest in impulsivity, distractibility, and low delay of gratification. This group exhibited significantly higher smartphone addiction scores compared to the others, reaching clinically addictive levels. Distinct self-control profiles are critically linked to smartphone addiction, with high impulsivity and insufficient self-control significantly increasing addiction risk.

The current study examined parent-child interactions and positive youth development (PYD) among 703 rural left-behind children (grades 3~6) in Meizhou City using self-report questionnaires. Latent profile analysis (LPA) was employed to explore the subcategories of parent-child interaction and their predictive effects on positive development. The results revealed that: ① left-behind children could be classified into three distinct subgroups based on parent-child interactions: the “low parent-child interaction group” (28.59%), the “moderate parent-child interaction group” (49.64%), and the “high parent-child interaction group” (21.76%); ② children in the “high parent-child interaction group” scored significantly higher on the overall PYD score and its five dimensions compared to the other groups. These findings not only validate the applicability of latent profile analysis in this study but also highlight the differential impact of varying levels of parent-child interactions on the positive development of left-behind children. The results provide important insights into the latent profile specificity of parent-child interactions among rural left-behind children and lay a theoretical foundation for developing differentiated intervention strategies. This study has significant academic value and practical implications for advancing research on the mental health of left-behind children and promoting relevant interventions.

To address the low material handling efficiency of Automated Guided Vehicle Systems (AGVS) in hot pressing workshop, a simulation model based on a unidirectional guided network layout was developed, using an automotive brake friction material enterprise A as a case study. First, task allocation was carried out under the original AGVS scheduling strategy, and offline path planning was performed using the A star algorithm. Results showed that the average transport distance per AGV task was reduced by 23.64% compared with pre-planning, thereby verifying the effectiveness of path optimization. On this basis, the AGVS scheduling strategy was further optimized by dynamically assigning tasks according to the distance between AGV locations and task origins, adopting task-by-task cyclic assignment and the Hungarian algorithm for concurrent tasks, and redefining the rules for AGV return after unloading. Simulation results indicate that the optimized strategy effectively reduces the average transport distance and task completion time per AGV, while lowering production costs. This study provides valuable insights for improving AGVS transport efficiency and advancing scheduling optimization in intelligent manufacturing workshops.

Geological hazard susceptibility assessment is an important foundation and effective means for identifying high-risk areas and disaster prevention and reduction. Using the Analytic Hierarchy Process and GIS spatial analysis methods, the vulnerability of geological hazards in Zhangjiakou was evaluated by constructing an evaluation index system and calculating the weight of indicator factors, and the risk level was classified. At the same time, the comparison and verification were conducted based on the historical disaster point data and assessment results that have occurred. Research shows that: ① Using the analytic hierarchy process, the evaluation index system and evaluation results of Zhangjiakou's geological hazard vulnerability based on three indicators and their factors of topography, ecology, and geological landforms are scientifically credible; ② The overall risk of geological disasters in Zhangjiakou is relatively high, with the proportion of areas in the four risk zones from high to low being 38.59%,27.79%,19.21%, and 14.40%, respectively; ③ By comparing the data of historical disaster points, it was confirmed that nearly 60% of historical disasters occurred in areas with high or above risk levels, and the risk classification results are highly consistent with the actual historical situation; ④ The causes of major geological disasters in Zhangjiakou are highly related to regional topography, climate, rivers, geological tectonic zones, and human activities.

Under innovation-driven development strategy, the relationship between informal connections and the innovation performance of enterprises has increasingly become a hot topic of common concern for scholars and the government in recent years. Based on the CiteSpace econometric analysis of the WOS and CNKI databases, 36 377 domestic and foreign literatures on the two themes of “informal connection” and “innovation performance” over the past four decades from 1985 to 2024 were selected for econometric analysis. The results show that: The research contents and focuses of domestic and foreign scholars on these two topics are highly related to the institutional environment, economic development level and enterprise innovation ability of the country and region. Research on the influence mechanism of informal connections on enterprise innovation performance focuses on three aspects: internal enterprise, inter-enterprise communication, and the interaction effect between enterprises and other subjects. However, the mechanism exploration of how informal connections affect enterprise innovation at a deeper level remains to be explored. In the future, further discussions can be carried out from entry points such as quantitative measurement of informal connections, dynamic analysis, and the interaction between formal and informal connections.