| 1. |
- Almusaed, Amjad, 1967-, et al.
(författare)
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An Innovative School Design Based on a Biophilic Approach Using the Appreciative Inquiry Model : Case Study Scandinavia
- 2022
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; Volume 2022, s. 1-18
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Forskningsöversikt (refereegranskat)abstract
- To understand the school’s role in society and its works, it became essential to reevaluate its functions and importance for society after the aggressive attack of the COVID-19 pandemic. Thus, a new educational space design represents a powerful and required tool for stimulating creativity and increasing concentration, motivation, and assimilation of knowledge for future generations. The article will use appreciative inquiry as a method that works with perspective ideas readings doted by high positive human sensitivity. It also represents a powerful tool for the students’ opinions about the teaching spaces and environments. To improve the performance of educational institutions and schools, considering the sustainability concepts and biophilic designs has become an urgent necessity within the Scandinavian countries and in the world in general. The scientific research and theoretical analysis within the biophilic theory have been conducted to see how the designer can integrate the nature components holistically in the educational environment based on spatial, visual, and ecological integration concepts. The study aims to develop knowledge about applying biophilia as a phenomenon in educational institutes of Scandinavia where the students among others are the main decision-maker. The article’s main finding is that students dream of free open teaching spaces integrated with nature, where the biophilic theory frameworks are suitable to form this sustainable model that enables educational institutions and schools to improve their performance within different stages of the study.
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| 2. |
- AlOmar, Mohamed Khalid, et al.
(författare)
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Data-Driven Model for the Prediction of Total Dissolved Gas : Robust Artificial Intelligence Approach
- 2020
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Ingår i: Advances in Civil Engineering / Hindawi. - London : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2020
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Tidskriftsartikel (refereegranskat)abstract
- Saturated total dissolved gas (TDG) is recently considered as a serious issue in the environmental engineering field since it standsbehind the reasons for increasing the mortality rates of fish and aquatic organisms. +e accurate and more reliable prediction ofTDG has a very significant role in preserving the diversity of aquatic organisms and reducing the phenomenon of fish deaths.Herein, two machine learning approaches called support vector regression (SVR) and extreme learning machine (ELM) have beenapplied to predict the saturated TDG% at USGS 14150000 and USGS 14181500 stations which are located in the USA. For theUSGS 14150000 station, the recorded samples from 13 October 2016 to 14 March 2019 (75%) were used for training set, and therest from 15 March 2019 to 13 October 2019 (25%) were used for testing requirements. Similarly, for USGS 14181500 station, thehourly data samples which covered the period from 9 June 2017 till 11 March 2019 were used for calibrating the models and from12 March 2019 until 9 October 2019 were used for testing the predictive models. Eight input combinations based on differentparameters have been established as well as nine statistical performance measures have been used for evaluating the accuracy ofadopted models, for instance, not limited, correlation of determination (R2), mean absolute relative error (MAE), and uncertaintyat 95% (U95). +e obtained results of the study for both stations revealed that the ELM managed efficiently to estimate the TDG incomparison to SVR technique. For USGS 14181500 station, the statistical measures for ELM (SVR) were, respectively, reported asR2 of 0.986 (0.986), MAE of 0.316 (0.441), and U95 of 3.592 (3.869). Lastly, for USGS 14181500 station, the statistical measures forELM (SVR) were, respectively, reported as R2 of 0.991 (0.991), MAE of 0.338 (0.396), and U95 of 0.832 (0.837). In addition, ELM’straining process computational time is stated to be much shorter than that of SVM. +e results also showed that the temperatureparameter was the most significant variable that influenced TDG relative to the other parameters. Overall, the proposed model(ELM) proved to be an appropriate and efficient computer-assisted technology for saturated TDG modeling that will contribute tothe basic knowledge of environmental considerations.
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| 3. |
- Altaee, Mohammed J., et al.
(författare)
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Evaluation of Existing Bond-Slip Relations for CFRP-Steel Joints and New Model for Linear and Nonlinear Adhesives
- 2022
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2022
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Tidskriftsartikel (refereegranskat)abstract
- Existing bond-slip (τ-s) relations for fibre-reinforced polymer (FRP)-steel joints employ different shapes and mathematical expressions, inferring that their predictions of failure load and mode, and other interface properties, might be inconsistent or inaccurate. In this study, predictions of four widely used τ-s relations are evaluated using a large experimental database of 78 double-lap FRP-steel specimens. To facilitate the evaluation process, a robust finite element (FE) model is developed for each test, implementing data from either of the existing τ-s relations to define the FRP-steel interface. Comparisons between test and FE results indicated that the existing τ-s models were unable of predicting the ultimate load (Pu) and effective bond length (Leff) of FRP-steel joints, or the relation between Pu and bond length and that between Leff and FRP modulus (Ef). A new τ-s model is developed based on an inverse FE simulation, comparison with experimental results, and regression analysis. It considers the effects of Ef, the type of FRP reinforcement (sheet or plate), and applies to both linear and nonlinear adhesives. The model predictions were validated by comparing with results from small bond tests and large FRP-strengthened steel beams tested under bending, yielding excellent results for Pu, failure mode, and all other interfacial properties.
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| 4. |
- Beza, Abebe Dress, et al.
(författare)
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How PTV Vissim Has Been Calibrated for the Simulation of Automated Vehicles in Literature?
- 2022
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Limited. - 1687-8086 .- 1687-8094. ; 2022
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Forskningsöversikt (refereegranskat)abstract
- Recently, in the literature, microscopic simulation is one of the most attractive methods in impact assessment of automated vehicles (AVs) on traffic flow. AVs can be divided into different categories, each having different driving characteristics. Hence, calibrating microscopic simulators for different AV categories could be challenging in AVs' impact assessment. The PTV Vissim microscopic traffic simulation software has been calibrated for simulating diverse types of AVs in a large body of literature. There are two main streams of studies in literature adapting AVs' driving behaviors in Vissim following either internal (i.e., adjusting the parameters of the Vissim's default driving behavior models) or external (i.e., adapting AVs' behavior through external VISSIM interfaces) modeling approaches. The current paper investigates how the PTV Vissim has been internally calibrated for the simulation of different types of AVs and compares the calibrated values in the literature with default values introduced in the recent version of PTV Vissim. In the present paper, the reviewed studies are partitioned into two main categories according to the characteristics of the studied AVs, the studies focused on autonomous automated vehicles (AAVs) and the ones focused on cooperative automated vehicles (CAVs). Our findings indicate that the literature expects a lower value for parameters including standstill distance (CC0), headway time (CC1), following variation (CC2), the threshold for entering "following" (CC3), negative/positive following thresholds (CC4/CC5), speed dependency of oscillation (CC6), oscillation acceleration (CC7), safety distance reduction factor (SDRF), and minimum headway front/rear (MinHW) for AVs than conventional vehicles (CVs). Besides, the literature expects higher values for parameters including standstill acceleration (CC8), acceleration at 80 km/h (CC9), looking distances, and maximum deceleration for cooperative braking (MaxDCB) for AVs. When cautious AVs are introduced, deterring effects are expected in the literature (e.g., higher CC0). Moreover, CAVs can have higher looking distance values compared with AAVs.
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| 5. |
- Bohling, Daniel, et al.
(författare)
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Bond Strength between Glass Fiber Fabrics and Low Water-to-Binder Ratio Mortar : Experimental Characterization
- 2018
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2018
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Tidskriftsartikel (refereegranskat)abstract
- Full utilization of mechanical properties of glass fiber fabric-reinforced cement composites is very limited due to a low bond strength between fibers and the binder matrix. An experimental setup was developed and evaluated to correlate the mortar penetration depth with several key parameters. The studied parameters included fresh mortar properties, compressive and flexural strengths of mortar, the fabric/mortar bond strength, fabric pullout strength, and a single-lap shear strength. Results showed that an average penetration of mortar did not exceed 100 µm even at a higher water-to-binder ratio. The maximum particle size of the used fillers should be below an average spacing of single glass fibers, which in this case was less than 20 µm to avoid the sieving effect, preventing effective penetration. The pullout strength was strongly affected by the penetration depth, while the single-lap shear strength was also additionally affected by the mechanical properties of the mortar.
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| 6. |
- Chen, Guangfu, et al.
(författare)
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Pile-Spacing Calculation of Anti-Slide Pile Based on Soil Arching Effect
- 2020
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Limited. - 1687-8086 .- 1687-8094. ; 2020
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Tidskriftsartikel (refereegranskat)abstract
- Anti-slide pile is one of the most frequently used measures in landslide control globally. Pile-spacing has always been determined by the load capacity of single piles or according to engineering empirical experience. Many engineering practices and laboratory experiments show that the soil arching effect exists in landslide control with anti-slide piles. In this study, we aim to calculate pile-spacing in terms of the soil arching effect. We investigated the pile-soil interaction mechanism and propose that, at the limit, the pile-back soil arch resists landslide thrust only. According to Mohr-Coulomb strength theory and limit equilibrium theories, we derived a new pile-spacing calculation equation. We verified the derived pile-spacing calculation equation with real projects. The calculated results are similar to those of practical engineering designs, in which the difference is within 10%. The equation can be used in anti-slide pile preliminary design. This study can be a reference for pile-spacing calculation based on the soil arching effect.
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| 7. |
- Dam, Nguyen Duc, et al.
(författare)
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Evaluation of Shannon Entropy and Weights of Evidence Models in Landslide Susceptibility Mapping for the Pithoragarh District of Uttarakhand State, India
- 2022
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2022
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Tidskriftsartikel (refereegranskat)abstract
- Landslide susceptibility mapping is considered a useful tool for planning, disaster management, and natural hazard mitigation of a region. Although there are different methods for predicting landslide susceptibility, the bivariate statistical analysis method is considered to be simple and popular. In this study, the main aim is to evaluate the performance of Shannon entropy (SE) and weights of evidence (WOE) statistical models in landslide susceptibility mapping of Pithoragarh district of Uttarakhand state, India. For this purpose, ten landslide affecting factors, namely, slope degree, aspect, curvature, elevation, land cover, slope forming materials, geomorphology (landforms), distance to rivers, distance to roads, and overburden depth were used for the development of landslide susceptibility maps using the SE and WOE methods. Data extracted from the Google Earth images, Aster Digital Elevation Model, and Geological Survey of India report were used for the construction and evaluation of landslide susceptibility models and maps. The landslide data of 91 locations were randomly divided into two parts in the ratio of 70 : 30 using GIS software that is 70% data was used for training the models and 30% data was used for testing and validating the models. Performance of the applied models was evaluated using area under the AUC (area under the curve) ROC (receiver operating characteristics) curve. Results indicated that the WOE model is having better accuracy (AUCWOE = 68.75%) than the SE model (AUCSE = 52.17%) in the development of landslide susceptibility maps. Hence, WOE model can be used for the development of accurate landslide susceptibility maps which can provide useful information to decision maker and policy planner in better development of landslide prone areas.
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| 8. |
- Girhammar, Ulf Arne, et al.
(författare)
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Tests and Analyses of Slotted-In Steel-Plate Connections in Composite Timber Shear Wall Panels
- 2017
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2017
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Tidskriftsartikel (refereegranskat)abstract
- The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.
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| 9. |
- Hameed, Mohammed Majeed, et al.
(författare)
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Predicting Compressive Strength of Concrete Containing Industrial Waste Materials: Novel and Hybrid Machine Learning Model
- 2022
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Publishing Corporation. - 1687-8086 .- 1687-8094. ; 2022
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Tidskriftsartikel (refereegranskat)abstract
- In the construction and cement manufacturing sectors, the development of artificial intelligence models has received remarkable progress and attention. This paper investigates the capacity of hybrid models conducted for predicting the compressive strength (CS) of concrete where the cement was partially replaced with ground granulated blast-furnace slag (FS) and fly ash (FA) materials. Accurate estimation of CS can reduce the cost and laboratory tests. Since the traditional method of calculation CS is complicated and requires lots of effort, this article presents new predictive models called SVR-PSO and SVR-GA, that are a hybridization of support vector regression (SVR) with improved particle swarm algorithm (PSO) and genetic algorithm (GA). Furthermore, the hybrid models (i.e., SVR-PSO and SVR-GA) were used for the first time to predict CS of concrete where the cement component is partially replaced. The improved PSO and GA are given essential roles in tuning the hyperparameters of the SVR model, which have a significant influence on model accuracy. The suggested models are evaluated against extreme learning machine (ELM) via quantitative and visual evaluations. The models are evaluated using eight statistical parameters, and then the SVR-PSO has provided the highest accuracy than comparative models. For instance, the SVR-PSO during the testing phase provided fewer root mean square error RMSE with 1.386 MPa, a higher Nash-Sutcliffe model efficiency coefficient (NE) of 0.972, and lower uncertainty at 95% (U95) with 28.776%. On the other hand, the SVR-GA and ELM models provide lower accuracy with RMSE of 2.826 MPa and 2.180, NE with 0.883 and 0.930, and U95 with 518.686 183.182, respectively. Sensitivity analysis is carried out to select the influential parameters that significantly affect CS. Overall, the proposed model showed a good prediction of CS of concrete where cement is partially replaced and outperformed 14 models developed in the previous studies.
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| 10. |
- Jensen, Jörgen L., et al.
(författare)
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Fracture Mechanics Models for Brittle Failure of Bottom Rails due to Uplift in Timber Frame Shear Walls
- 2016
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Ingår i: Advances in Civil Engineering / Hindawi. - : Hindawi Limited. - 1687-8086 .- 1687-8094.
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Tidskriftsartikel (refereegranskat)abstract
- In partially anchored timber frame shear walls, hold-down devices are not provided; hence the uplift forces are transferred by the fasteners of the sheathing-to-framing joints into the bottom rail and via anchor bolts from the bottom rail into the foundation. Since the force in the anchor bolts and the sheathing-to-framing joints do not act in the same vertical plane, the bottom rail is subjected to tensile stresses perpendicular to the grain and splitting of the bottom rail may occur. This paper presents simple analytical models based on fracture mechanics for the analysis of such bottom rails. An existing model is reviewed and several alternative models are derived and compared qualitatively and with experimental data. It is concluded that several of the fracture mechanics models lead to failure load predictions which seem in sufficiently good agreement with the experimental results to justify their application in practical design.
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