Engineering Construction Research Articles

Research on Teaching Reform of Smoke Control and Exhaust Course under the Background of New Engineering

A large number of fire cases have proven that smoke is the main cause of casualties in fires, with over 80% of victims dying directly or indirectly due to smoke. Scientific and rational design of smoke control systems is crucial for slowing down the spread of fires and ensuring safe evacuation time. At present, the process of smoke exhaust in fire scenes is still the main way of fire rescue utilization, and industries related to smoke exhaust are also one of the main employment areas for undergraduate students majoring in fire engineering. However, traditional smoke exhaust engineering courses have outdated teaching content, teaching methods, and assessment methods, which cannot meet the demand for cultivating technical talents in energy engineering majors under the background of new engineering construction. This study first starts from the characteristics of smoke control engineering courses and the problems existing in teaching. Using advanced online teaching platforms, advanced teaching aids, mature commercial software, and computer programming language design environments, the teaching content of smoke control engineering courses is upgraded and transformed towards modular computing, intelligent design, and other directions. In the context of new engineering disciplines, students' learning interests are enhanced, and their practical, innovative, and comprehensive computing abilities are exercised.

Changes in the Properties of Two Typical Plant Species and Their Rhizosphere Bacteria in Eco‐Restoration of Engineered Slopes on the Qinghai–Tibet Plateau

ABSTRACTSlopes that are created by extensive engineering construction projects accelerate the degradation of the ecologically fragile Qinghai–Tibetan Plateau. This adverse impact can be mitigated by implementing ecologically sound restoration programs in these degraded sites. This study investigated the changes in the physiology of two typical plant species and their rhizosphere bacteria on four different engineered slopes subjected to eco‐restoration on the Qinghai–Tibet Plateau. The findings showed that the shear strength, nutrition, and enzymatic activity of the plant rhizosphere improved significantly, and these were positively associated with the restoration effect on vegetation. The growth and development of plants in the frame beam group and the shotcrete group were optimized. The microbial diversity in the plant rhizosphere soil in the restoration areas exhibited a comparable degree of change to the control soil, characterized by a decrease in the relative abundance of microbial phyla and alterations in the indicator species at the order level. However, the community stability in the restoration areas was notably higher than that in the control group. This study offers significant implications and practical value for the eco‐restoration of engineered slopes in alpine regions, which provides a sustainable development framework for protecting fragile ecosystems.

Geostress-Adaptive Charge Structure Design and Field Validation for Machinery Room Excavation

The application of blasting in modern engineering construction is prized for its speed, efficiency, and cost-effectiveness. However, the resultant vibrations can have significant adverse effects on surrounding buildings and residents. The challenge of optimizing blasting procedures to satisfy excavation needs while minimizing vibration impacts is a critical concern in blasting excavation. This research addresses this challenge through the development of a 3D simulation and analysis model for an underground pumped storage power plant in East China, utilizing the LS-DYNA finite element analysis software. To explore the influence of charging structures on rock fragmentation and vibration propagation, three distinct blasting programs were formulated, each featuring varied configurations within the machinery room. The analysis revealed that the adoption of an optimized charging structure can significantly decrease damage to the protective layer by approximately 40%, while also reducing the impact on the upstream and downstream side walls by 27.25% and 12.03%, respectively, without compromising the efficacy of the main blast zone. Moreover, the vibration velocities at the remote measurement point were found to be reduced across multiple directions, indicating effective control of the vibration effects. The post-implementation of the optimized blasting strategy at the site, the assessment of the retained surrounding rock integrity, and the impact on protected structures demonstrated that the proposed solution met satisfactory outcomes. This study underscores the potential of simulation-based optimization in managing vibration risks during blasting operations, offering a valuable tool for engineers and practitioners in the field of underground construction.

Culturing 3D chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds in a dynamic environment enhances osteochondral reconstruction.

Bioreactor can provide a dynamic culture environment for the in vitro construction of osteochondral tissue engineering. They facilitate more efficient exchange of nutrients and provide mechanical and other beneficial stimulation. Previous findings demonstrated that rotary flask (RF) bioreactor, rotary cell culture system (RCCS), or electromagnetic field (EMF) mediated scaffold culture could create a favorable dynamic environment for osteochondral tissue engineering. However, it is still unclear whether there is an optimal bioreactor or if bioreactors under multi-parameter coupling conditions are conducive to osteochondral tissue engineering. Based on this, the application of static T-flask (TF), RF, RCCS, and coupling environment of RCCS and EMF for osteochondral tissue engineering were systematically compared. The results showed that the RCCS/EMF culture system achieved the highest level of cellular proliferation and directed differentiation. Compared with the static culture group, the expression levels of chondrogenic factors of Sox9, Col II, and ACAN and osteogenic factors of Runx2, OCN, and Col I in RCCS/EMF culture system were 2.90±0.10, 3.53±0.05, 3.15±0.08, 7.16±0.15, 5.01±0.21 and 3.99±0.17 folds, respectively. The 'Active osteochondral' constructs (The construct is composed of chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds) were prepared under different culture modes in vitro and implanted into the femoral condylar defect of New Zealand rabbits. After 12weeks, all culture modes could effectively promote the repair of osteochondral defects, in which the RCCS/EMF intervention had the best effect on the in vivo in-situ repair of osteochondral tissues. Furthermore, the fabricated cartilage and subchondral bone in the RCCS/EMF treatment group were most similar to the surrounding natural tissues, providing a new therapeutic idea for osteochondral tissue engineering.

Intelligent Monitoring System for Roller-Compacted Earth-Rock Dam Construction Process

Abstract The conventional quality control method of earth-rock dam is insufficient to meet the requirements of intelligent and fine management of dam filling construction in the new stage. With the expansion of construction scale and the overall improvement in information technology level, the traditional compaction quality control methods no longer meet the demands of modern mechanized rapid construction or provide real-time compaction information for engineering contractors. In response to the current conventional design and construction schemes for earth-rock dams, an intelligent real-time monitoring system established in this paper for compaction construction of earth-rock dams. This system utilizes advanced Beidou high-precision positioning and navigation technology, vibration-sensing IoT technology, real-time processing of massive construction information, and BIM technology. It achieves real-time intelligent monitoring of key compaction processes in dam construction and refined management of unit engineering. The intelligent system established provides crucial technical support for the safe and reliable operation of water conservancy and hydropower projects. Simultaneously, it enables real-time, remote, and intelligent monitoring of dam construction processes, significantly enhancing the technological content and informatization level of water conservancy engineering construction.

Triaxial test on load-bear capacity of the vibro-compaction coral sand foundation in the South China Sea

Vibro-compaction is the main improvement method for hydraulic reclamation coral sand sites. Currently, the load-bearing characteristics of coral sand composite foundation reinforced by vibro-compaction have not been clarified. This paper investigates strength characteristics of coral sand composite samples (core and shell) by artificially preparing radial variable-density coral sand composite samples and performing consolidated drained triaxial tests under different area replacement rates, core-shell density ratios, and confining pressures. The results of the study show that the contribution of the core gradually increases with the increasing area replacement rate. The peak strength and peak friction angle of samples also increase gradually, but the growth tendency gradually slows down. The stress concentration coefficient of sample core is variable and follows a development pattern of first increasing and then decreasing. The secant Young's modulus of composite samples increases in a power function type with the increase of area replacement rate. The particle breakage of samples is mainly the rupture and abrasion of the 0.5-1 mm and 0.1-0.25 mm particle groups that serve as fillers. The research results can provide technical support for coral reef engineering construction.

Capital budgeting for electrical engineering projects: A practical methodology

The paper presents the capital budgeting process and identifies key elements in the process. A standardized approach in capital budgeting by application of information technology resources for both proposal submission and documentation becomes key to success in handling large volumes. An electrical engineering distribution system design project involves the application of engineering codes and standards to stay compliant and provide safe design and construction. A model starting with proposals acceptance to evaluation and approval of capital projects was presented. The proposal stage was decoded further into assessments of the existing electrical infrastructure based on aging and engineering standards. Upon review of the standards, the proposals were accepted for evaluation and approval. For business professionals, there is a gap when working in an electrical engineering construction industry when it comes to knowing applicable engineering standards and their application. This research filled that gap by enlisting the intent of the standards review process. Although the focus was on understanding a holistic approach to electrical engineering projects, a detailed analysis of specific tasks may be designed based on the model presented in this paper. Additionally, the transmission side of projects will have a similar application of capital budgeting.

Buildings: Special Issue on Advancement in Research on Structural Dynamics and Health Monitoring

The rapid development of engineering materials, construction technologies, and analytical approaches has made it possible to design and build more slender structures, with longer spans and taller heights [...]

Research on the Construction Path of New Engineering + Curriculum Ideology and Politics

With the rapid development of science and technology and the transformation and upgrading of industry, new engineering construction has become the important direction of higher engineering education reform in our country. This research focuses on the “new engineering + curriculum ideological and political new form course construction path,” in order to meet the new requirements of talent training put forward by the development of new engineering. This paper analyzes the educational value and current situation of curriculum ideology and politics under the background of new engineering, and improves the ability of curriculum ideology and politics from the perspective of strengthening the teacher training system; optimizing curriculum ideological and political design, skillfully integrating into the ideological and political elements; and strengthening the cooperation between schools, enterprises, and family associations to enrich curriculum ideological and political resources. To build a collaborative education mechanism and form an all-round education pattern, the four aspects of the new engineering + curriculum ideological and political of the new form course construction path have been preliminarily explored, hoping to provide some references and guidance.

Increases in vegetation cover increase response more to climate change than to human activities in the Baiyangdian watershed

Abstract Baiyangdian watershed is located in the upstream of Xiongan New Area, and as an important ecological source of the new area, its vegetation cover status has an important impact on the environmental quality and ecological health of the new area. By analysing the spatial and temporal characteristics of vegetation cover in the Baiyangdian watershed, we investigated the response of climate change and human activities to vegetation cover, and revealed the evolution patterns and driving mechanisms of vegetation cover under changing environments. Utilizing the Google Earth Engine (GEE) and Landsat remote sensing images, the normalized difference vegetation index (NDVI) of the Baiyangdian watershed from 1992 to 2022 was extracted. The temporal and spatial characteristics of vegetation cover were determined using Theil-Sen Median and Mann-Kendall analysis, while factors influencing the spatiotemporal changes in vegetation cover in Baiyangdian were explored through correlation and residual analyses reveal the following: (1) Vegetation cover in the study area showed an increasing trend over time, with a spatial increase from northwest to southeast, revealing the recovery of the ecological environment; (2) Vegetation cover was positively correlated with precipitation and temperature, and the effect of temperature on Baiyangdian was greater than that of precipitation; (3) Residual analyses showed that human activities and climate change had an increasing role in contributing to vegetation cover, and that the dominant factor had changed from human activities to climate changes. The residual analysis shows that human activities and climate change are increasing the vegetation cover, and the dominant factor is changing from human activities to climate change. This study provides a scientific basis for the ecological management of Baiyangdian and the construction of forestry engineering.

Influence of Particle Rotation on the Shear Characteristics of Calcareous-Sand and Silica-Bead Granular Materials

The shear strength and resistance of granular materials are critical indicators in geotechnical engineering and infrastructure construction. Both sliding and rotation influence the energy evolution of soil granular motion during shear. To examine the effects of particle rotation on shear damage and energy evolution in granular systems, we first describe the transformation of irregularly shaped particles into regular shapes via geometrical parameters, ensuring the invariance of energy density and density. We then analyze the impact of particle rotation on shear-stress variation and energy dissipation through a shear energy evolution equation. Additionally, we establish the relationship between the shear-stress ratio and normal stress, considering particle rotation. Finally, we verify the influence of particle rotation on energy evolution and shear damage through shear tests on irregular calcareous sand and regular silica-bead particles. The results indicate that granular materials do not fully comply with the Coulomb strength criterion. In the initial shear stage, most of the external work is converted into granular rotational-shear energy, whereas in the later stage, it primarily shifts to granular sliding-shear energy. Notably, the sensitivity of the granular rotational energy to a vertical load is significantly greater than that of the granular sliding energy.

Influence of fiber type on the mechanical performance and fracture mechanism of fiber reinforced concrete under coupled static-dynamic compression

As a high-performance building material, fiber-reinforced concrete (FRC) has attracted garnered significant interest in practical engineering construction. However, the effect of coupled static-dynamic loading on the dynamic response of FRC remains far from understood, which seriously limits its wide application. In this study, a series of coupled static-dynamic loading tests are conducted on four types of FRC specimens using the modified split Hopkinson pressure bar (SHPB) system, and the influences of static pre-stress and strain rate on the mechanical performance of FRC under coupled static-dynamic loading are systematically analyzed. The experimental results indicate that static pre-stress generally reduces the dynamic strength and energy dissipation density, but increases the total strength and fragmentation degree of FRC. As the pre-stress ratio increases from 0 to 0.6, the dynamic strength of FRC decreases ranging from 12 to 25 %, and the total strength increases ranging from 12 to 34 %. The failure features of FRC specimens changes from tensile failure mechanism to tensile-shear mixed mechanism with increasing the static pre-stress. Combining the scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) techniques, the microscopic structure and fracture mechanisms of FRC specimens are revealed, and the underlying influencing mechanisms of the static pre-stress, strain rate and fibers are further discussed. The axial pre-stress exerts a dual effect on FRC: enhancement by compacting primary voids as well as attenuation by stimulating secondary microcracks. The strain rate dominates the mechanical performance of FRC under coupled static-dynamic loading, and the influence of pre-stress is diminished by higher strain rates. In addition, the fiber incorporation strengthens the concrete pore structure by bridging action and crack inhibition, resulting in superior mechanical performance compared to normal concrete under coupled static-dynamic loading conditions.

Finite Element Analysis of the Structural Behavior of a Corroded Pipe Culvert

The stress analysis of buried pipe culverts is a complex task, and accurately characterizing the deterioration of mechanical properties caused by corrosion poses significant challenges. In this study, the finite element analysis software PLAXIS 3D was employed to construct a numerical simulation model of a pipe culvert. By varying the stiffness and thickness of either the entire structure or specific sections, different degrees of corrosion were simulated to investigate the influence of various cross-sectional shapes on corrosion effects. Multiple experimental controls were set to analyze both the bearing capacity and deformation characteristics under different conditions. The findings reveal that different levels of corrosion have distinct impacts on the deformation behavior of pipe culverts. Overall corrosion has the most significant effect on the overall deformation, while crown and middle corrosion show a similar effect on stiffness-related deformations. In contrast, invert corrosion has minimal impact on the stiffness-related deformation. Corrosion affects circular and elliptical pipe culverts similarly. However, the circular pipe culvert is evidently influenced by overall corrosion more significantly than the elliptical ones due to the combined effects from overall and local corrosion in their deformations. Through finite element numerical simulation, it can be used as a reference for practical engineering design and construction.

Prevalence of hearing loss among noise-exposed U.S. workers within the Construction sector, 2010–2019

Background: The purpose of this cross-sectional study is to estimate the prevalence of hearing loss among noise-exposed U.S. workers during 2010–2019 within the Construction sector. Methods: Audiograms for 26,653 workers at 833 Construction companies (and for 1.3 million other workers) were examined. Period prevalence and adjusted risk for hearing loss as compared with a reference industry (Couriers and Messengers) were estimated for the Construction sector and sub-sectors, and all industries combined. Results: The prevalence of hearing loss within the Construction sector was 23% compared to 20% for all industries combined. Several sub-sectors exceeded the overall prevalence and all but two had adjusted risks significantly higher than the reference industry. The sub-sectors with the highest prevalences for hearing loss were: Highway, Street, and Bridge Construction (28%), Site Preparation Contractors (26%), New Single-Family Housing Construction (except Operative Builders) (25%), Oil and Gas Pipeline and Related Structures Construction (25%), and Other Building Finishing Contractors (25%). The sub-sectors with the highest adjusted risks were Industrial Building Construction; Other Heavy and Civil Engineering Construction; Oil and Gas Pipeline and Related Structures Construction; Finish Carpentry Contractors; and Site Preparation Contractors; with risks 62%, 61%, 60%, 59% and 58% higher than the reference industry, respectively. Conclusions: Hearing loss continues to be a significant issue within Construction. Reducing noise exposure is critical, including buying quieter equipment, keeping moving parts oiled and well-maintained, enclosing noise sources, and employing administrative controls to reduce the number of workers in noisy areas. Barriers to workers consistently and correctly wearing their hearing protection also need to be addressed. Practical Applications: Within Construction, hazardous noise is common and the risk of hearing loss is high. This study identified the Construction sub-sectors with the highest prevalences and risks to guide interventions toward workers most in need of prevention and described strategies for reducing exposures.

Evolution of the Yigong river channel on the Eastern edge of the Qinghai-Tibet Plateau: insights from hydrodynamic geological hazards shaping topography

Geological action is one of the main forces in the formation of topography, especially in the southeastern part of the Qinghai-Tibet Plateau. Collapse, landslide, mud-rock flow and other geological actions are the main factors affecting the evolution of river valley landforms. However, existing inference methods primarily rely on theoretical calculations and multi-temporal remote sensing image interpretation, lacking direct analysis and validation through geological exploration techniques. In response, this study employed geological engineering and geotechnical exploration techniques to investigate the impact of debris flows, landslides, and collapses on the evolution of topography and geomorphology in a 5.0 km section of the Yigong Zangbo Basin. Through drilling and geophysical exploration, 6 geological profiles were constructed, identifying the distribution range and development characteristics of the geological phenomena within this section of the river valley, revealing the distribution positions of both the new and old river channels, and inferring the evolution of the river bedrock based on the original topography. The study found that when geological phenomena occur, substantial material is transported into the river channel, altering its original shape and influencing the river’s erosion process. Additionally, the occurrence of geological phenomena is closely correlated with the evolution of river valley morphology. When the river valley is wide, material accumulation on one side causes the river to flow along a lower position on the opposite side, primarily resulting in the river’s bending on the plane. In contrast, in narrow river valleys, material accumulation on the sides can fill the entire river channel, leading to a rise in the riverbed. These research findings provide a critical theoretical basis for understanding river valley morphological evolution and informing basin engineering construction.

Mechanical properties and damage characterization of cracked granite after cyclic temperature action

Due to the unique geographical environment of the plateau, large-scale damage and destruction of fractured surrounding rock often occur during geotechnical engineering construction as a result of high-temperature cycles. Therefore, this study aims to investigate the mechanical properties and damage characteristics of fractured granite under the influence of cyclic temperature, uniaxial compression tests were conducted on granite specimens with pre-existing fractures at cyclic temperatures of 30 °C, 50 °C, 70 °C, 100 °C, and 130 °C. The study integrated analyses of characteristic stress, acoustic emission parameters, damage variables, fractal dimensions, and SEM to explore the mechanical properties and damage features of granite. The results indicated that at a 45° fracture inclination and a temperature of 70 °C, granite exhibited a distinct turning point in mechanical properties and damage characteristics. At the same cyclic temperature, granite with a 45° pre-existing fracture showed significant decreases in peak stress, elastic modulus, and σci/σm ratios, with the AE b-value drop point noticeably earlier, and both cumulative AE ring count and total energy reduced. The damage variable quickly reached its maximum, and the development of internal microcracks in the specimen is highly orderly. At the same fracture inclination, peak stress, elastic modulus, and σci/σm slightly increased at 70 °C, while AE ring counts and total energy were lower, indicating the degree of internal thermal damage in the specimen has significantly decreased, and the development of internal microcracks in the specimen has shown a marked reduction in orderliness. These findings provide theoretical insight into the meso-damage and failure mechanisms of granite influenced by different cyclic temperatures and fracture inclinations.

Matini-Net: Versatile Material Informatics Research Framework for Feature Engineering and Deep Neural Network Design.

In this study, we introduced Matini-Net, which is a versatile framework for feature engineering and automated architecture design for materials informatics research using deep neural networks. Matini-Net provides the flexibility to design feature-based, graph-based, and combinations of these models, accommodating both single- and multimodal model architectures. For validation, we performed a performance evaluation on the MatBench benchmarking dataset of five properties, targeting five types of regression architectures that can be designed using Matini-Net. When applied to each of the five material property datasets, the best model performance for the various architectures exhibited R2 > 0.84. This highlights the usefulness and flexibility of Matini-Net for accelerating materials discovery. Specifically, this framework was developed for researchers with limited experience in deep learning to easily apply it to research through automated feature engineering, hyperparameter tuning, and network construction. Moreover, Matini-Net improves the model interpretability by performing an importance analysis of the selected features. We believe that by employing Matini-Net, machine and deep learning can be applied more easily and effectively in various types of materials research.

Confined Truths and Cognitive Ecologies: When the Social Pursuit of Questioning Becomes Unreliable

AbstractThe capacity to distinguish reliable or rationally believable claims from a huge pool of views available within the public arena has never been as critical an issue as it is today. We live in a world full of bizarre, unwarranted beliefs and conspiracy theories, some of which may seem, at least on the face of it, quite well justified. Moreover, some of them may even turn out to be true. This poses a significant social-epistemological as well as practical problem. Here I propose to single out a group of beliefs known as confined truths. These are true beliefs belonging to a pathological question-answer system. The paper first provisionally articulates this idea and then makes the case for an ecological account of questioning and answering, thought of as social pursuits made possible by the capacity for problematization. The latter shall be characterized as part of cognitive engineering or niche construction. In the final part of the paper, various possible dysfunctionalities of the social/ecological pursuit of problematization are elicited and suitable examples thereof are briefly discussed.

Effect of High-Stress Levels on the Shear Behavior of Geosynthetic-Reinforced Marine Coral Sands

As an important construction material, the mechanical and deformation properties of marine coral sand determine the safety and stability of related island and coastal engineering construction. The porous and easily broken characteristics of coral sand often make it difficult to meet engineering construction needs. In particular, coral sand undergoes a large amount of particle breakage under high-stress conditions, which in turn negatively affects its mechanical and deformation properties. In this study, the macro- and micro-mechanical behavior of geosynthetic-reinforced coral sand under high confining pressure was investigated and compared with unreinforced cases using the three-dimensional discrete element method (DEM), which was verified by indoor triaxial tests. The results showed that the stress–strain responses of unreinforced and reinforced coral sand under high confining pressure showed completely different trends, i.e., the hardening tendency shown in the reinforced case. Geosynthetic reinforcement can significantly inhibit the stress–strain softening and bulging deformation of coral sand under high confining pressure, thus improving the shear mechanical performance of the reinforced sample. At the microscopic scale, high confining pressure and reinforcement affected the contact force distribution pattern and stress level between particles, determining the macroscopic mechanical and deformation performance. In addition, the breakage of particles under high confining pressure was mainly affected by shear strain and reinforcement. The particle fragment distribution, particle gradation, and relative breakage index exhibited different trends at different confining pressure levels. These breakage characteristics were closely related to the deformation and stress levels of unreinforced and reinforced samples.

Design, perspectives, and challenges of modification strategies for alkali metal anodes

Abstract. The alkali metal anode has emerged as a focal point of research due to its extremely low oxidation-reduction potential and high theoretical specific capacity. However, challenges such as unstable solid electrolyte interphase (SEI), infinite volume expansion, and uncontrollable dendrite growth result in low coulombic efficiency and irreversible losses during the deposition and stripping processes. To address these issues, various effective strategies have been proposed to protect the alkali metal anode and achieve dendrite-free growth. In this review, we summarize recent advancements in enhancement strategies for alkali metal anodes, including the construction of three-dimensional current collectors and interface engineering. Specifically, we delve into the development of carbon-based current collectors with various dimensions and structures and the application of interface engineering techniques to tackle the challenges of unstable SEI, volume changes, and dendrite growth. Furthermore, we explore advanced characterization techniques that provide deeper insights into the reaction mechanisms and behavior of these enhancement strategies. Finally, we discuss the current limitations and future research directions in protecting alkali metal anodes, aiming to provide valuable insights into the study of dendrite growth and the development of effective protection strategies for alkali metal anodes.