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Number of results: 118
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Abstract

The aim of this study is to find the cost design of RC tension with varying conditions using the Artificial Neural Network. Design constraints were used to cover all reliable design parameters, such as limiting cross sectional dimensions and; their reinforcement ratio and even the beahviour of optimally designed sections. The design of the RC tension members were made using Indian and European standard specifications which were discussed. The designed tension members according to both codes satisfy the strength and serviceability criteria. While no literature is available on the optimal design of RC tension members, the cross-sectional dimensions of the tension membersfor different grades of concrete and steel, and area of formwork are considered as the variables in the present optimum design model. A design example is explained and the results are presented. It is concluded that the proposed optimum design model yields rational, reliable, and practical designs.

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Authors and Affiliations

N. Karthiga Shenbagam
N. Arunachalam
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Abstract

This work deals with the analysis of elasto-plastic post-buckling state of rectangular laminated plates subjected to combined loads, such as uniform compression and shear. The plates are built of specially orthotropic symmetrical layers. The analysis is carried out on the basis of nonlinear theory of orthotropic plates involving plasticity. The solution can be obtained in the analytical-numerical way using Prandtl-Reuss equations. The preliminary results of numerical calculations are also presented in figures.
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Authors and Affiliations

Ryszard Grądzki
Katarzyna Kowal-Michalska
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Abstract

The effect of air humidity on transonic flow around an NACA0012 airfoil at flow conditions, characteristic for buffet phenomenon, was investigated experimentally. Airfoil angles of attack in the range from 6° up to 10° were used, whereas values of initial relative air humidity were kept constant at four values 12%, 40%, 60% and 80%. Reconstructed time depending airfoil pressure distributions, time histories of normal aerodynamic force coefficient C, as well values of C0 pulsation are shown on the basis of surface pressure measurements at various humidity levels. The influence of the air humidity on the buffet origin is presented.
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Authors and Affiliations

Z. Nosal
W.C. Selerowicz
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Abstract

The assessment of a rock’s behaviour around excavations and the effectiveness of its reinforcement in underground ore mines is dependent on the performance of the rock-bolt and rock-mass interaction, which can be estimated on the basis of appropriately designed measurements. Based on the background of various measurements solutions described in the literature, concerning rock bolt monitoring methods, the authors proposed a new, original device for mass measurements in mine conditions. After examining the advantages and disadvantages of existing constructions, the article presents the essence, principle of operation and method of measuring anchor load in an underground excavation with the a instrument, indicator WK-2/8. The prototype has been carefully researched and successfully tested in a full-scale laboratory environment. This instrument, also referred to as a load indicator or force pad, does not require electrical power and allows for relatively accurate (with a resolution of 10-14kN, up to about 90kN loading capacity) and a remote reading of the axle loading of the anchor (AGH patent) by any person present in the specified area. The device can be installed in mining excavations under loading conditions. The relatively low cost of a measuring instrument, practically used as an additional washer, as well as an easy assembly method, makes it universally applicable in mines where anchoring is used as a means of strengthening the rock.

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Authors and Affiliations

Waldemar Korzeniowski
Krzysztof Skrzypkowski
Łukasz Herezy
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Abstract

A flow around an NACA00 12 airfoil at special transonic flow conditions, characterised by damped oscillations of the main flow velocity, was investigated experimentally. On the basic of pressure measurements and flow visualisation, the time depending airfoil loading was reconstructed. Results, presented for a wide range of angle of attack ( a =Q-;-10°), show that during the excitation the normal aerodynamic force behaviour significantly differs from that of quasi- steady conditions. The pressure distributions on the airfoil surface depend on Mach number of the main flow as well on the phase of oscillation (deceleration or acceleration of the main flow velocity). The influence of the air humidity on the pressure distribution, normal aerodynamic force and centre of pressure is also considered.
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Authors and Affiliations

Witold C. Selerowicz
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Abstract

The effect of air humidity on oscillatory flow around the NACA 0012 airfoil was investigated experimentally at Mach number M=0.71 and airfoil angle of attack a=8.5''. The background tlow oscillations were produced by a rotating rectangular plate placed downstream of the airfoil. The generated oscillation frequencies were in the range from 0.5 up to 1.5 of the buffet frequency. The presented results shown that the normal aerodynamic force variations strongly depend on the excitation frequency and reach a maximum value at frequencies typical to the buffet. The increase of the air humidity leads to considerable diminishing of the aerodynamic force variation.
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Authors and Affiliations

Witold C. Selerowicz
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Abstract

Green mine construction is the main melody of mining development and problems such as safe production, energy saving and consumption reduction need to be solved urgently. The working conditions of the mill are complex in the process of grinding. Aiming at the problems existing in the feature extraction and load prediction of the mill, a signal-processing method based on adaptive chirp mode decomposition (ACMD) and a standardized variable distance classifier (SVD) is proposed. Firstly, the recursive framework of the ACMD method is used to obtain the initial frequency of mill vibration signals. Secondly, the initial frequency is used to reconstruct the high-resolution component of the mill vibration signal through the iterative frame in the ACMD method. The frequency corresponding to the frequency domain peak of the reconstructed signal is then selected as the mill load feature vector. Finally, with consideration to the influence of standard deviation and standardized variable factors on the feature vectors, a standardized variable distance classifier is proposed. The feature vectors of the mill load are input into the SVD model for training, and the state types of the mill load are obtained. The method is applied to the grinding experiment and the results show that the frequency-domain features obtained by the mill vibration signal-processing method based on ACMD-SVD are obvious, which has high accuracy in the identification of mill load types, and provides a new idea for the extraction of mill load features and prediction of the mill load.
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Authors and Affiliations

Wencong Tang
1
Fangwei Zhang
1
Xiaoyan Luo
1
ORCID: ORCID
Junliang Wan
1
Tao Deng
1

  1. Jiangxi University of Science and Technology, China
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Abstract

The research was conducted in a relatively small (26.8 ha) but quite deep (17.3 m) Lake Długie in Olsztyn, Poland. For over 20 years the lake was collecting sewage which eventually caused its complete degradation. In 1987-2000 the lake was restored using the artificial aeration method with destratification of water. The results showed that the artificial aeration effectively limited the internal loading. Application of this restoration method resulted in reduction of phosphorus compounds concentrations in the analyzed water strata. The decrease of TP in bottom sediments (to the level of 3-4 mg P g·' DW) was probably associated with the fact that a new layer of sediments was created, reflecting a change in the aquatic conditions caused by the restoration. The investigations conducted in the reference years showed that the changes were not permanent. A high concentration of phosphorus compounds in bottom sediments, low sorptivc capacity and a tendency to oxygen deficiency, indicate that further possibility to decrease the amount of phosphorus compounds in the lake by this restoration method is limited.
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Authors and Affiliations

Renata Brzozowska
Helena Gawrońska
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Abstract

In order to keep the WWTP performance under control and to make decisions of minimizing the potential influence of wastewater components on the stable and proper WWTP operation, the devices for on-line control of oxygen uptake rate were designed and manufactured. The devices were used for three aims: controlling the presence of harmful substances for microorganisms in raw wastewater (Toximctcr), assessment of the real physiological condition of activated sludge in the aeration chamber (Activmcter), determining of the effects of activated sludge settling properties deterioration and its influence on the secondary clarificrs operation as well as microorganisms presence in treated wastewater (Sedimctcr). The results confirmed that the devices arc helpful for the WWTP operators as an early warning system and enable optimal decisions making.
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Authors and Affiliations

Korneliusz Miksch
Joanna Surmacz-Górska
Piotr Ostrowski
Katarzyna Przybyła
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Abstract

This article presents the results of experimental studies aimed at identifying the forces and acceleration during the riding and braking action of a suspended monorail. The tests were conducted under in situ conditions, in a dip-heading “B” ZG SILTECH in Zabrze. The paper also discusses a test stand, a metering system, and presents the impact of changes in speed on forces in slings of the suspended route. The measurements of selected parameters were performed for three variants: the route, the emergency haulage braking and the braking trolley set braking. The results include waveforms of forces in route slings, and acceleration values acting on the operator and transported load.

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Authors and Affiliations

Jarosław Andrzej Tokarczyk
Marek Rotkegel
ORCID: ORCID
Andrzej Pytlik
Andrzej Niedworok
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Abstract

The Convolutional Neural Network (CNN) model is one of the most effective models for load forecasting with hyperparameters which can be used not only to determine the CNN structure and but also to train the CNN model. This paper proposes a framework for Grid Search hyperparameters of the CNN model. In a training process, the optimal models will specify conditions that satisfy requirement for minimum of accuracy scores of Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE) and Mean Absolute Error (MAE). In the testing process, these optimal models will be used to evaluate the results along with all other ones. The results indicated that the optimal models have accuracy scores near the minimum values. Load demand data of Queensland (Australia) and Ho Chi Minh City (Vietnam) were utilized to verify the accuracy and reliability of the Grid Search framework.
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Bibliography

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[9] Yang J.,Wang Q., A Deep Learning Load Forecasting Method Based on Load Type Recognition, 2018 International Conference on Machine Learning and Cybernetics (ICMLC), Chengdu, pp. 173–177 (2018).
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[18] Jojo Moolayil, Learn Keras for Deep Neural Networks: A Fast-Track Approach to Modern Deep Learning with Python, Apress (2018).
[19] Xishuang Dong, Lijun Qian, Lei Huang, Short-term load forecasting in smart grid: A combined CNN and K-means clustering approach, IEEE Int. Conf. Big Data Smart Comput., pp. 119–125 (2017).
[20] Dong X., Qian L., Huang L., A CNN based bagging learning approach to short-term load forecasting in smart grid, 2017 SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI, San Francisco, CA, 2017, pp. 1–6 (2017).
[21] Voß M., Bender-Saebelkampf C., Albayrak S., Residential Short-Term Load Forecasting Using Convolutional Neural Networks, 2018 IEEE International Conference on Communications, Control, and Computing Technologies for Smart Grids (SmartGridComm), Aalborg, 2018, pp. 1–6 (2018).
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[27] Wang Y., Ma X., Wang F., Hou X., Sun H., Zheng K., Dynamic electric vehicles charging load allocation strategy for residential area, Archives of Electrical Engineering, vol. 67, no. 3, pp. 641–654 (2018).
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Authors and Affiliations

Thanh Ngoc Tran
1

  1. Faculty of Electrical Engineering Technology, Industrial University of Ho Chi Minh City, 12 Nguyen Van Bao, Ward 4, Go Vap District, Ho Chi Minh City, Vietnam
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Abstract

The paper presents the assumptions and methodology for investigating equivalent heat load testing of hot aircraft engine components. The basic heat loads occurring in an aircraft engine during aircraft flight are characterised. Diagrams of the proposed heat loads are presented, together with the number of cycles, and a test bench is characterised and shown to enable equivalent heat load testing of aircraft engine components.
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Bibliography

[1] Hejwowski, T., Weroński, A. (2000). Manufacture of wear-resistant coatings. Lublin: Politechnika Lubelska. (in Polish).
[2] Research stand in WSK PZL Rzeszów.
[3] Chaur, - Jeng Wang, & Jiaun, - Sheng Lin (2002). The oxidation of MAR M247 superalloy with Na2SO4 coating. Materials Chemistry and Physics. 76, 123-129. DOI: 10.1016/S0254-0584(01)00527-2.
[4] Goebel, J.A., Petit, F.S. & Howard, G.W. (1973). Mechanism for the hot corrosion of nickel base alloys. Metallurgical Transactions. 4, 261-270. https://doi.org/10.1007/BF02649626.
[5] Su, C.Y., Lih, W.C., Chou, C.P. & Tsai, H.C. (2001). Activated diffusion brased repair for IN 738 hot section components of gas turbine. Journal of Materials Processing Technology. 115(3), 326-332.

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Authors and Affiliations

Marek Mróz
ORCID: ORCID
A.W. Orłowicz
1
ORCID: ORCID
M. Tupaj
1
ORCID: ORCID
M. Lenik
1
ORCID: ORCID

  1. Rzeszow University of Technology, Al. Powstańców Warszawy 12, 35-959 Rzeszów, Poland
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Abstract

The article is a continuation of a study on the synthesis of matching multi-terminal networks, also known as compensators. The reactive four-terminal-network compensators for linear loads were introduced in previous publications, but it appeared that they operate effectively with nonlinear loads too. The methods to create a compensator for a mono-harmonic source, which allows complete independence of input from output waveforms, ensuring optimal operating conditions for the source, are presented herein. The work for the first time presents the optimal four-terminal-network compensator applied to a nonlinear load.

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Authors and Affiliations

M. Jaraczewski
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Abstract

Slender systems are mostly studied when Euler’s load or follower load is considered. The use of those types of external loads results in well-known divergence or flutter shape of the characteristic curve. In this study, one takes into account the specific load which allows one to obtain an interesting divergence – pseudo flutter shape of characteristic curves on the external load–vibration frequency plane. The curves can change inclination angle as well as one can observe the change in vibration modes along them. The shape of those curves depends not only on the parameters of the slender system but also on loading heads that induce the specific load. In this study, one considers the slender multimember system in which cracks are present and weaken the host structure. The results of theoretical as well as numerical simulations are focused on the influence of the parameters of the loading heads on vibrations, stability, and loading capacity of the investigated system as well as on the possibility of partial reduction of unwanted crack effect.
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Authors and Affiliations

Krzysztof Sokół
1
ORCID: ORCID
Krzysztof Kuliński
2

  1. Department of Mechanics and Machine Design Foundations, Czestochowa University of Technology, Czestochowa, Poland
  2. Department of Civil Engineering, Czestochowa University of Technology, Czestochowa, Poland
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Abstract

Balconies are elements of some multi-storey buildings. Thermo-insulated fasteners are components that connect balcony slabs with the building structure. Their main task is the transfer of loads in connections of balcony slabs with the building while also minimizing thermal bridges. The article presents analytical calculations performed to develop the new type of thermal insulated fasteners and to determine their load-bearing capacity. The aim of this article is to demonstrate that analytical calculations based on commonly utilized principles of reinforced concrete and steel structure operation along enable the development of the effective design algorithm of insulated fasteners and allow for a quick analysis of various geometric variants of these fasteners. The article presents the adaptation of typical algorithms for calculation of steel and reinforced concrete structures for the analysis of non-typical load-bearing capacity states that occur during the calculation of insulated fasteners. The load-bearing capacities of individual fasteners are shown in M-V interaction diagrams (bending moment – shearing force).
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Authors and Affiliations

Tomasz Janiak
1
ORCID: ORCID

  1. Bydgoszcz University of Science and Technology, Faculty of Civil and Environmental Engineering and Architecture, Al. prof. S. Kaliskiego 7, 85-796 Bydgoszcz, Poland
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Abstract

Results and low-cycle fatigue tests analysis of 45 steel in conditions of block programmed loading with a different sequence of levels were presented in the paper. During tests four types of programs were applied: gradually increasing, gradually decreasing, gradually increasing and decreasing, and irregular. The sequence of levels in the block loading program was the parameter, which diversified the applied programs. The results of tests were analysed in the aspect of influence of loading program character on the course of the stabilization process. The analysis of the stabilization process was performed by comparing the stress loading amplitude for the chosen levels of the program in the following blocks. The hardening index was proposed as a description of the stabilization process. The comparative analysis showed similarity of the stabilization processes both under the programmed and the constant - amplitude loading.
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Authors and Affiliations

Stanisław Mroziński
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Abstract

The paper contains a comparison of the results of calculation and experiment for the IOHNAP alloy steel. Specimens made of this steel were subjected to uniaxial constant-amplitude and random loading with both zero and non-zero mean values of loading. For determination of the steel fatigue life, the energy parameter including the mean value of loading was proposed. Under random loading, cycles were counted with the rain flow algorithm, and fatigue damage was accumulated with the Palmgren-Miner hypothesis. For the registered stress histories, elastic-plastic strains were calculated with the kinematic hardening model proposed by Mróz.
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Authors and Affiliations

Aleksander Karolczuk
Krzysztof Kluger
Tadeusz Łagoda
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Abstract

The author presents an algorithm of slewing motion control in telescopic crane mounted on a chassis of a truck (mobile crane). The control algorithm allows the crane to carry load to a selected point, and it also ensures suppression of swing at the endpoint of the motion. The attention was focussed mainly on the control of slewing motion of the crane body in the case of non-planar distribution of forces acting on the load during its motion.
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Authors and Affiliations

Jacek Kłosiński
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Abstract

Bridge crane is exposed to dynamic loads during its non-stationary operations (acceleration and braking). Analyzing these operations, one can determine unknown impacts on the dynamic behavior of bridge crane. These impacts are taken into consideration using selected coefficients inside the dynamic model. Dynamic modelling of a bridge crane in vertical plane is performed in the operation of the hoist mechanism. The dynamic model is obtained using data from a real bridge crane system. Two cases have been analyzed: acceleration of a load freely suspended on the rope when it is lifted and acceleration of a load during the lowering process. Physical quantities that are most important for this research are the values of stress and deformation of main girders. Size of deformation at the middle point of the main crane girder is monitored and analyzed for the above-mentioned two cases. Using the values of maximum deformation, one also obtains maximum stress values in the supporting construction of the crane.
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Bibliography

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[4] D. Cekus, P. Kwiatoń, and T. Geisler. The dynamic analysis of load motion during the interaction of wind pressure. Meccanica, 56:785–796, 2021. doi: 10.1007/s11012-020-01234-x.
[5] J. Yuan, C. Schwingshackl, C. Wong, and L. Salles. On an improved adaptive reduced-order model for the computation of steady-state vibrations in large-scale non-conservative systems with friction joints. Nonlinear Dynamics, 103:3283–3300, 2021. doi: 10.1007/s11071-020-05890-2.
[6] H. Zhu, J. Li, W. Tian, S. Weng, Y. Peng, Z. Zhang, and Z. Chen. An enhanced substructure-based response sensitivity method for finite element model updating of large-scale structures. Mechanical Systems and Signal Processing, 154:107359, 2021. doi: 10.1016/j.ymssp.2020.107359.
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[21] D. Ostric, A. Brkic, and N. Zrnic. The analysis of bridge cranes dynamic behaviour during the work of hoisting mechanism. Proceedings of XIV IcoMHaW, Faculty of Mechanical Engineering, Belgrade, 1996.
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Authors and Affiliations

Mirsad Čolić
1
Nedim Pervan
1
ORCID: ORCID
Muamer Delić
1
ORCID: ORCID
Adis J. Muminović
1
ORCID: ORCID
Senad Odžak
2
ORCID: ORCID
Vahidin Hadžiabdić
1
ORCID: ORCID

  1. Faculty of Mechanical Engineering, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
  2. Faculty of Science, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
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Abstract

The paper presents an analysis of a 100-meter wind measurement guyed mast located in the north-western part of the United States, in the state of Oregon. Using the RFEM software [1], the influence of the wind on the mast was analyzed according to the guidelines of two standards: American TIA-222-H [2] and European EN 1993-3-1 [3]. The purpose of this work is to show the differences between the results of static computations of the mast in terms of the considered standards. Due to the limited content of the work, the icing load on the structure was ignored in the analysis and the focus was on determining the response of the mast only in terms of wind action. The author tried to describe the differences in this respect between the standard guidelines [2] and [3]. The comments and conclusions regarding the analysis of guyed masts presented in the article have some practical aspects and can be used in design practice.
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Authors and Affiliations

Renata Pigoń
1
ORCID: ORCID

  1. Koszalin University of Technology, Faculty of Civil Engineering, Environmental and Geodesy, ul. Sniadeckich 2, 75-453 Koszalin, Poland
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Abstract

Prediction of propagation time of corrosion is a key element in evaluating the service life of corroded reinforced concrete (RC) structures. Corroded steel products often expand in volume and thus generate tensile stress in the concrete cover. When this tensile stress exceeds the tensile strength of the concrete, cracking occurs. The tensile stresses in concrete due to corrosion are usually perpendicular to the longitudinal axis of the reinforcement. In the reinforced concrete beams, tensile stresses in concrete due to bending is perpendicular to the longitudinal direction of stirrups. In the reinforced concrete slabs, the tensile stresses in concrete due to bending is also perpendicular to the axis of longitudinal reinforcement subjected to bending in the other direction. In such cases, the tensile stresses in concrete due to corrosion of reinforcement has the same direction as the tensile stress caused by bending. When the load-induced stress in the concrete has the same direction as that of the corrosion-induced stress, cracks will likely appear more quickly and vice versa. The main objective of this paper is to build a predictive model of corrosion propagation time taking into account: (1) the effect of stresses due to load; (2) the change of corrosion current density. The model was implemented on Matlab software. The results show the influence of the load, and other parameters on the corrosion propagation stage, when considering the end of this corrosion propagation stage is cracking of concrete cover.
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Authors and Affiliations

Dao Van Dinh
1
ORCID: ORCID
Tran Viet Hung
1
ORCID: ORCID

  1. Structural Engineering Section – University of Transport and Communications Add: No.3 Cau Giay Street, Lang Thuong ward, Dong Da District, Hanoi, Vietnam
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Abstract

The intensive agricultural use of the land affects both quantity and quality of river water in the catchment area. Such impact is visible also in the Szreniawa River catchment in the Małopolskie Voivodeship. The combination of intensive plowing and soil susceptibility to water erosion are the main causes of soil and nutrients depletion during the heavy rainfall. The aim of the study is to determine changes in the water quality in the Szreniawa River catchment compared to the agri-culture use and precipitation level.

The quality of surface water has been analysed in the river catchment area in three sampling points. The concentration of the total suspended soils in the samples collected after heavy rainfall in August 2017 reached a value of 837 mg·dm–3. The average concentrations of N-NO3 in the years of 2016–2019 ranged from 0.16 to 13.46 mg·dm–3, with the highest val-ues in the summer (up to 13.46 mg·dm–3). The concentration of N-NH4 and P-PO4 in the Szreniawa water was affected by precipitation. The highest value of average concentration of N-NH4 3.00 mg·dm–3 was recorded in the autumn of 2019 in the middle section of the river. The highest value of P-PO4 0.90 mg·dm–3 was recorded in the autumn of 2019 mostly due to water erosion of the loess areas. Erosion has been caused by the short-term heavy rainfall. As a result, suspended solids, soluble and insoluble phosphorus compounds leaked to the river.

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Authors and Affiliations

Agnieszka W. Kowalczyk
ORCID: ORCID
Marek Kopacz
ORCID: ORCID
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Abstract

A theoretical formula for large-diameter rock-socket depth is developed to support pail embedding in a large bridge pile foundation project. There is a horizontal additional stress concentration at the place where the soil around the rock-socketed pile meets the soil layer under the horizontal load. When the rock-socketed tip stress and bending moment of the pile are relatively small, the pile shows favourable embedment effect and the pile foundation can be considered safe. The function curve of soil resistance around the pile under the action of horizontal force was obtained by finite element analysis. The force characteristics reveal the depth of the largediameter rock-socketed pile under the horizontal load. As the rock-socketed pile rotates under the action of horizontal force, the rock mass resistance around the pile changes according to the cosine. The distribution of pileside soil resistance is proportional to the displacement and distributed according to the sine. A comprehensive correction coefficient of pile shaft resistance beta is introduced to deduce the theoretical formula of the depth r h of the large-diameter rock-socketed pile embedded in the bedrock. It is verified through both experiments and numerical analysis.
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Authors and Affiliations

Yanfeng F. Li
ORCID: ORCID
Jihe Zhao
1
ORCID: ORCID
Ying Xiong
1
ORCID: ORCID
Qinghe Wang
2
ORCID: ORCID

  1. DSc., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China
  2. Prof., PhD., School of Transportation Engineering, Shenyang Jianzhu University, Shenyang 110168, China

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