Semantic segmentation-based framework for concrete pouring progress monitoring by using multiple surveillance cameras

Traditional construction progress monitoring methods face challenges in real-time monitoring of concrete pouring due to performance limitations and issues with registration and occlusion. This study proposes a framework based on multi-camera semantic fusion for monitoring the progress of concrete pouring. The construction site images are first segmented into semantic probabilities by a deep neural network. Dempster-Shafer evidence theory is then applied for semantic fusion, providing a comprehensive depiction of the progress. To reduce registration errors with the Building Information Model (BIM), a real-time perspective transformation algorithm is proposed to compensate for slight camera movements. Finally, a semantic inference method based on fully-connected Conditional Random Fields (CRFs) is employed to address occlusion by leveraging semantic context and the BIM floor plan. Comparative analysis confirmed these modules’ performance, with a remarkable reduction in relative error from 9.60% to 0.26%, enabling great potential for the continuous real-time monitoring of concrete pouring progress

Parameter Analysis of Wall Thickness of Cured-in-Place Pipe Linings for Semistructured Rehabilitation of Concrete Drainage Pipe

Frequent accidents caused by underground pipeline damage are a widespread societal concern. Trenchless rehabilitation methods, particularly cured-in-place pipe (CIPP) lining, are increasingly used for pipeline repair with great success. Existing research is mainly concerned with practical improvements in rehabilitation and evaluating the performance of rehabilitation. In this study, the model of corroded buried concrete pipeline that had been rehabilitated with CIPP was established using numerical methods, and the Mesh-based parallel-Code Coupling Interface (MpCCI) was used to investigate multifield coupling effects of soil pressure, traffic load, and fluid-structure interactions. Moreover, the influences of corrosion depth, corrosion width, traffic load, cover depth, and water quantity on CIPP wall thickness were compared and analyzed. The result shows that maximum principal stress and vertical displacement of pipeline markedly decreased after CIPP rehabilitation, and thus the new CIPP can carry loads in a deteriorated pipe. Stress and displacement of the composite pipe liner were positively correlated with corrosion depth and negatively correlated with corrosion width. Increase in traffic load rapidly increases von Mises stress of CIPP, and increase in cover depth rapidly increases maximum principal stress of pipeline. Water flow has little effect on the pipe liner, and flow capacity increases slightly after CIPP rehabilitation. CIPP wall thickness was positively correlated with corrosion depth, traffic load, cover depth, and water quantity and negatively correlated with corrosion width

Computer Vision-Based Construction Process Sensing for Cyber–Physical Systems: A Review

Cyber–physical systems (CPSs) are generally considered to be the next generation of engineered systems. However, the actual application of CPSs in the Architecture, Engineering and Construction (AEC) industry is still at a low level. The sensing method in the construction process plays a very important role in the establishment of CPSs. Therefore, the purpose of this paper is to discuss the application potential of computer vision-based sensing methods and provide practical suggestions through a literature review. This paper provides a review of the current application of CPSs in the AEC industry, summarizes the current knowledge gaps, and discusses the problems with the current construction site sensing approach. Considering the unique advantages of the computer vision (CV) method at the construction site, the application of CV for different construction entities was reviewed and summarized to achieve a CV-based construction site sensing approach for construction process CPSs. The potential of CPS can be further stimulated by providing rich information from on-site sensing using CV methods. According to the review, this approach has unique advantages in the specific environment of the construction site. Based on the current knowledge gap identified in the literature review, this paper proposes a novel concept of visual-based construction site sensing method for CPS application, and an architecture for CV-based CPS is proposed as an implementation of this concept. The main contribution of this paper is to propose a CPS architecture using computer vision as the main information acquisition method based on the literature review. This architecture innovatively introduces computer vision as a sensing method of construction sites, and realizes low-cost and non-invasive information acquisition in complex construction scenarios. This method can be used as an important supplement to on-site sensing to further promote the automation and intelligence of the construction process

IFC-Based 4D Construction Management Information Model of Prefabricated Buildings and Its Application in Graph Database

Effective data interoperability and schedule analysis play a significant role in improving the management of prefabricated buildings. However, there is a lack of efficient strategies and comprehensive approaches for data interoperability and data-based automated schedule analysis. This paper intends to promote prefabricated buildings’ management by solving these two problems via developing an IFC-based framework consisting of three parts. Firstly, this framework proposed a mechanism to establish an IFC-based 4D construction management information model of prefabricated buildings. Furthermore, a non-relational database—graph database—is introduced to twin this model into a task-centered network to realize the interoperation of construction information among different participants. Finally, graph database-based strategies to update data, automatically analyze construction schedules and visualize the 4D construction management information model are described. The proposed framework is validated in a prefabricated engineering case. In this case, an IFC-based and graph database-based 4D construction management information model is established through IFC standard’s extension. The graph database-based analysis of the model automatically recognizes the engineering case’s critical path information, delay analysis information, and schedule network analysis information. It is illustrated that this framework can successfully establish a unified IFC-based information model of prefabricated buildings’ construction management to prompt effective data interoperability. In addition, the application of this IFC-based information model in graph database can automatically analyze the construction schedules to prevent possible delays in advance. In short, the significance of this paper is to innovatively propose an IFC-based and graph data-based information model to solve the difficulties of ineffective data interoperation and unautomated schedule analysis in prefabricated buildings’ construction management. This study can be the digital foundation of further IFC-based digital twin

Effect of Nitrogen and Phosphorus Distribution in Overlying Water and Sediment of Major Rivers in Changchun City on Water Quality

To explore the existing characteristics of nitrogen and phosphorus in the main rivers of Changchun City, the overlying water and sediment were sampled and tested. The results showed that the spatial distribution of nitrogen and phosphorus contents in overlying water and sediment was diverse. In overlying water, nitrogen and phosphorus contents in the north and west of Changchun were high, while their contents in the south were low. In the sediment, their contents were high in the south and west and low in the north. The pollution of nitrogen and phosphorus was serious in most rivers. Xinkai River, Chuan Lake, and West Lake had the acutest pollution of ammonia, total nitrogen, and total phosphorus, and their contamination degree in Yongchun River was the lowest. In terms of time, with the government actively carrying out river management, the pollution control of ammonia and phosphorus has achieved remarkable results. The pollution of nitrogen and phosphorus was closely related to the quality of the water environment, and the phosphorus content in overlying water and sediment had the strongest correlation with other water quality parameters. Moreover, the change in chemical oxygen demand could be predicted by the partial least squares method on the basis of its high correlation with nitrogen and phosphorus in overlying water. This study provides a scientific reference for the investigation and treatment of nitrogen and phosphorus pollution in surface water of typical old industrial cities in China

Effect of Nitrogen and Phosphorus Distribution in Overlying Water and Sediment of Major Rivers in Changchun City on Water Quality

To explore the existing characteristics of nitrogen and phosphorus in the main rivers of Changchun City, the overlying water and sediment were sampled and tested. The results showed that the spatial distribution of nitrogen and phosphorus contents in overlying water and sediment was diverse. In overlying water, nitrogen and phosphorus contents in the north and west of Changchun were high, while their contents in the south were low. In the sediment, their contents were high in the south and west and low in the north. The pollution of nitrogen and phosphorus was serious in most rivers. Xinkai River, Chuan Lake, and West Lake had the acutest pollution of ammonia, total nitrogen, and total phosphorus, and their contamination degree in Yongchun River was the lowest. In terms of time, with the government actively carrying out river management, the pollution control of ammonia and phosphorus has achieved remarkable results. The pollution of nitrogen and phosphorus was closely related to the quality of the water environment, and the phosphorus content in overlying water and sediment had the strongest correlation with other water quality parameters. Moreover, the change in chemical oxygen demand could be predicted by the partial least squares method on the basis of its high correlation with nitrogen and phosphorus in overlying water. This study provides a scientific reference for the investigation and treatment of nitrogen and phosphorus pollution in surface water of typical old industrial cities in China

World-class Xincheng gold deposit: An example from the giant Jiaodong gold province

The Jiaodong gold deposits are currently the most important gold resources (with Au reserves of >4000 t) in China, and the leading gold-producing country globally (with Au production of ∼428 t in 2013). Jiaodong is also considered as perhaps the only world-class to giant gold accumulation on the planet where relatively young gold ores (ca. 130–120 Ma) were deposited in rocks that are 2 Ga older. The Xincheng world-class high-grade gold deposit, with a proven reserve of >200 t gold, is one of the largest deposits in the giant gold province of the Jiaodong Peninsula. It is located in the northwestern part of the Jiaobei Uplift, and hosted by ca. 132–123 Ma Xincheng quartz monzonites and monzogranites. Ore zones are structurally controlled by the NE-trending and NW-dipping Jiaojia Fault and subsidiary faults, and are mainly restricted to the footwall of the fault. The dominant disseminated- and stockwork-style ores are associated with strong sericitization, silicification, sulfidation and K-feldspathization, and minor carbonate wallrock alteration halos. The four mineralization stages are pyrite–quartz–sericite (stage 1), quartz–pyrite (stage 2), quartz–polysulfide (stage 3) and quartz–carbonate (stage 4). Gold occurs dominantly as electrum, with lesser amounts of sulfide-hosted native gold and rare native silver and argentite, normally associated with pyrite, chalcopyrite, galena and sphalerite: the latter with proven resources of about 105 t Ag, 713 t Cu, and 5100 t S. There are three types of ore-related fluid inclusions: type 1 aqueous-carbonate (H2O–CO2), type 2 aqueous (liquid H2O + vapor H2O), and type 3 CO2 (liquid CO2 and vapor CO2) inclusions. Homogenization temperatures range from 221 to 304 °C for type 1 inclusions, with salinities of 2.4–13.3 wt.% NaCl eq., and bulk densities of 0.858–1.022 g/cm3. The δ34SCDT values of hydrothermal sulfides are 4.3–10.6‰ and δ18O values of hydrothermal quartz have a median value of 13.0‰. δD values of fluid inclusions in hydrothermal quartz have a median value of −75‰. Calculated δ18Owater has a median value of 5.2‰. The timing of gold mineralization at the Xincheng gold deposit is younger than 123 ± 1 Ma, and likely between 120.9 and 119.9 Ma. A minerals system genetic model for the probable epizonal orogenic Xincheng deposit suggests an initial medium temperature, CO2-rich, and low salinity H2O–CO2 deeply sourced metamorphic ore fluid associated with dehydration and decarbonization of subducting Paleo-Pacific lithosphere. The Jiaojia Fault constrained the migration of ore-forming fluids and metals at the brittle–ductile transition. Fluid immiscibility, caused by episodic pressure drops, led to significant high-grade gold deposition in the giant Xincheng gold deposit

Adsorption of Pb, Cu and Cd from Water on Coal Fly Ash-Red Mud Modified Composite Material: Characterization and Mechanism

The rational utilization of solid waste has always been a worldwide concern. In this study, coal fly ash (CFA) and red mud (RM) were used in combination to synthesize efficient heavy metal adsorbents. A new way of resource recycling was provided with the collaborative reuse of CFA and RM. To obtain the modified composite materials, CFA and RM were mixed and melted in three ratios. After modification, these materials were then utilized to adsorb Pb, Cu, and Cd in water in both single and ternary systems. The physicochemical properties of CFA, RM, and three modified composite materials were measured by X-ray diffraction analysis, energy dispersive X-ray spectroscopy, scanning electron microscope, Fourier transform infrared spectroscopy, vibrating sample magnetometer, surface area analyzer, and porosity analyzer. In the single and ternary systems, the effects of the modified composite material dosage, solution pH, initial concentration of heavy metals, and adsorption time were discussed, and the results were better fitted with the Langmuir isotherm and the pseudo-second-order kinetic. It was discovered that the modified composite materials had a greater specific surface area (63.83 m2/g) than CFA and RM alone, as well as superior adsorption capacity and magnetic characteristics. The adsorption capacities of C1R4 for Pb, Cu, and Cd were 149.81 mg/g, 135.96 mg/g, and 127.82 mg/g in the single system, while those of Cu and Cd decreased slightly in the ternary system, and the preferential adsorption order of the modified composite materials for heavy metal ions was Pb > Cu > Cd. Among the three modified composite materials, C1R4 had the best adsorption capacity

Enhancement of the mariculture wastewater treatment based on the bacterial-microalgal consortium

Though bacterial-microalgal consortium (BM) system showed significant advantages for the mariculture wastewater treatment, how the high saline to the degradation of nitrogen, phosphorus and organic component shift need to be further investigated. In this study, three systems including the microalgae system (MA), activated sludge system (AS) and BM were parallel operated. The mariculture wastewater treatment performance and the shifts of soluble microbial products (SMPs) components were compared among the above systems. The result showed that the highest removals of NH4+-N (92.78%), PO43−-P (79.47%) and total organic carbon (TOC) (81.67%) were obtained in the BM system. This result demonstrated that the confederate effect between bacteria and microalgae showed satisfying mariculture wastewater treatment performance compared to the individual MA or AS system. In terms of the SMP production, the high salinity resulted in much SMP accumulation (178.89 mg/L of protein and 71.35 chancinmg/L of carbohydrate) in the MA system. Fortunately, the high salinity inhibition effect was dramatic reduction with less SMP accumulation in the BM system. The EEM result showed amounts of macromolecular organics of protein (aromatic-like substances and tryptophan-like substances) were the main components in the MA system, which were much higher than that in the AS and BM system. This indicated the macromolecular protein-like matters could not be removed absolutely based the individual MA system. Comparatively, the composition of SMP was shifted by the bacterial-microalgal consortium with less humic-like matters and tryptophan-like matters production in the BM system. The less SMP release had advantage to the stable operation of the bacterial-microalgal consortium. Hence, the bacterial-microalgal consortium contributed to a much stable micro-ecological environment formation for enhancing the high salinity mariculture wastewater treatment performanc