Deformations Of Fastenings Of Slopes Of Retaining Structures At Technological Purpose Reservoirs

2020 ◽  
pp. 62-72
Keyword(s):  
Reinforced Concrete ◽  
Land Reclamation ◽  
Factor Model ◽  
The Body ◽  
Water Bodies ◽  
Shore Protection ◽  
Retaining Structures ◽  
Reinforced Concrete Slabs ◽  
Equilibrium Profile ◽  
Protection Structures

The article presents the data of field, laboratory and theoretical studies, which made it possible to determine that processing, abrasion destruction of natural shores and loose upstream slopes of dams and enclosing structures, takes place on technological water bodies of Belarus - regardless of their economic use - technical, drinking water supply, regulation of runoff, energy, land reclamation, etc. The period of development of the processing process and the formation of the equilibrium profile is divided into a number of time periods (stages). Three stages are distinguished for the conditions of water bodies in Belarus: initial, intense dynamics and attenuation (equilibrium). Based on the data of field surveys of shore protection structures, the current state of various types of fasteners is assessed with the identification of the causes of their destruction and the extent of deformations. It has been established that the most common shore and slope fastenings are fastenings in the form of reinforced concrete monolithic or prefabricated plates. It is determined that the most widespread are the deformations of the fastenings in the form of the disclosure of inter-tile construction, temperature and settlement joints. As a result of opening the joints of the plates, the destruction and washing out of the sand and gravel bed, the formation of hollows and niches in the body of the slope with its subsequent processing, deformation and destruction of the fastening take place. It should be noted that the destruction of the fastening also occurs in stages, and the stages of the destruction of the fastening coincide with the staging of the processing of loose ground slopes. Based on the data of full-scale and experimental laboratory studies, scientifically substantiated criteria for assessing the stability of soil slopes and slopes with fastening by reinforced concrete slabs are proposed, which can be used to predict the state of designed and operated shore protection structures and fastening slopes. An enlarged methodology has been developed for assessing the risks abrasion of coasts and slopes of retaining structures based on the proposed territorial coefficient of abrasion risk, a mathematical factor model of risk based on the fault tree, and also an experimental electronic map of the risks of abrasion for the conditions of water bodies in the Minsk region of Belarus are developed.

Shore protection structures of water bodies. Part 1

2018 ◽  
Keyword(s):  
Water Bodies ◽  
Shore Protection ◽  
Protection Structures

В учебном пособии изложены основные сведения по берегоукрепительным сооружениям водных объектов. В нем содержатся рекомендации по конструированию отдельных элементов берегоукрепления, при этом основной акцент сделан на использование природных и природоприближенных материалов, гибких откосных конструкций с приоритетом экологических требований. Даны краткие рекомендации по методам расчета параметров берегоукрепления разных типов и оценки их стоимостных показателей. Учебное пособие содержит сведения, необходимые для формирования профессиональных компетенций при подготовке бакалавров по направлению 20.03.02 «Природообустройство и водопользование» и рекомендуется Научно-методическим советом по природообустройству и водопользованию для использования в учебном процессе. Учебное пособие может быть использовано студентами при выполнении курсовых и дипломных проектов, курсовых и выпускных работ бакалаврами и магистрами других направлений подготовки и специальностей факультетов РГАУ-МСХА, студентами сельскохозяйственных и строительных вузов, выполняющих домашние задания и расчетно-графические работы.

scholarly journals Deformations of upper soil slopes of retaining structures and shores with violated reinforced concrete fastening in riverbed reservoirs in Belarus

2021 ◽  
Vol 21 (1) ◽  
pp. 29-41
Author(s):  
Viktor Levkevich ◽  
Aleksandr Buzuk ◽  
Ivan Kirvel ◽  
Sergey Parfomuk
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Equilibrium ◽  
Wind Waves ◽  
Retaining Structures ◽  
Field Surveys ◽  
Water Currents ◽  
Soil Slopes ◽  
Equilibrium Profile ◽  
The Stability ◽  
Engineering Protection

Abstract The conditions of wind waves influence on the ground upper soil slopes of retaining structures and natural shores that are fixed in the form of reinforced concrete fastening with deformations are considered. The results of modeling the regime of intra-water currents and field surveys of artificial water bodies are shown. A criterion for assessing the stability of ground slopes and coastal slopes with reinforced concrete fastening with a broken structure is proposed and the conditions for its applicability are determined. Measures for engineering protection of the reservoir shores are proposed via using a criterion for the stability of fixed slopes Пк. It is assumed that at Пк ≥ 1 the slope profile with fastening plates deformed during operation acquires the contour of the dynamic equilibrium profile adopted for the calculated type of soil as a result of the destruction of the slope by waves.

Bank protection structures of the cascade of water reservoirs of the Vilia-Minsk water system

2019 ◽  
pp. 48-58
Keyword(s):  
Wind Waves ◽  
Water System ◽  
Field Studies ◽  
The Body ◽  
Coastal Protection ◽  
Field Observations ◽  
Shore Protection ◽  
Current State ◽  
National University ◽  
Protection Structures

The data of field studies of shore protection structures in the reservoirs of the Vilia-Minsk water system are given, the current state of various types of fastenings is assessed with the reasons for their destruction and the extent of deformation. The article presents the results of field observations of coastal shelter-type structures. It is shown that the most common anchorages of banks and slopes is to protect the surface of slopes in the form of reinforced monolithic or precast slabs. It is determined that the deformations of the slope anchorages are most often represented by the opening of inter-tile construction, temperature and sedimentary seams (the opening width is registered to 0.35 m) which develop under the complex influence of wind waves, fluctuations in levels and other factors. Subsequently, the deformation of the exposed seams lead to the destruction of the attachment. Experimentally, on the basis of physical modeling of deformations of slopes made in the hydrotechnical laboratory of the Belarusian National University on models of soil supporting structures protected by reinforced concrete fastening, it was established that as a result of opening the seams of the plates, the sand-gravel preparation and the formation of sinuses and niches in the body of the support structure occur , which leads to significant processing of the ground slope. The coastal protection structures of the active type in the form of laid and beach slopes are considered. The dependencies on the calculation of slope deformations are obtained on the basis of a generalization of the data of field observations.

Shore protection structures of water bodies. Part 2

2018 ◽  
Keyword(s):  
Water Bodies ◽  
Shore Protection ◽  
Protection Structures

В учебном пособии изложены основные сведения по берегоукрепительным сооружениям водных объектов. В нем содержатся рекомендации по конструированию отдельных элементов берегоукрепления, при этом основной акцент сделан на использование природных и природоприближённых материалов, гибких откосных конструкций с приоритетом экологических требований. Даны краткие рекомендации по методам расчёта параметров берегоукрепления разных типов и оценки их стоимостных показателей. Учебное пособие содержит сведения, необходимые для формирования профессиональных компетенций при подготовке бакалавров по направлению 20.03.02 «Природообустройство и водопользование» и рекомендуется Научно-методическим советом по природообустройству и водопользованию для использования в учебном процессе. Учебное пособие может быть использовано студентами при выполнении курсовых и дипломных проектов, курсовых и выпускных работ бакалаврами и магистрами других направлений подготовки и специальностей факультетов РГАУ-МСХА, студентами сельскохозяйственных и строительных вузов, выполняющих домашние задания и расчётно-графические работы.

scholarly journals Slope Protection Structures at Water Reservoirs in Belarus and Causes of their Deformations

2018 ◽  
Vol 17 (6) ◽  
pp. 478-488
Author(s):  
V. E. Levkevich
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Equilibrium ◽  
Wind Waves ◽  
Coastal Protection ◽  
Water Reservoirs ◽  
Retaining Structures ◽  
Site Investigations ◽  
Bank Stabilization ◽  
Opening Width ◽  
Protection Structures

Assessment of the current state in respect of various bank stabilization with identification of causes of their destruction and deformation scale has been carried out on the basis of the survey pertaining to coastal protection structures in more than 100 reservoirs of the country. The paper presents results of field observations on bank slope protection structures which are used at water reservoirs in Belarus. It has been established that the most common protection of banks and slopes is strengthening in the form of reinforced concrete monolithic or prefabricated slabs. It has been determined that deformations of slope protection are represented by opening of tile-to-tile construction, temperature and settlement joints (it has been recorded opening width of 0.35 m) which develop under a complex impact of wind waves, fluctuations in levels and other factors. Subsequently deformations of exposed joints lead to destruction of the protection. Value of slope deformations reaches in some cases rather significant extent: linear processing (destruction) of slopes – up to 24.20 m; volume of erosion – up to 4.25 m3/m running. Physical modeling of slope deformations carried out at a hydro-technical laboratory of the Belarusian National Technical University while using models of ground retaining structures protected by reinforced concrete strengthening with various opening width of joints has allowed to determine dynamics and scope of slope deformations due to the influence of wave and level regimes having various parameters. Data of on-site investigations on protection have made it possible to assess the state of slope paving for various operational periods of retaining structures. The paper presents reasons and factors that affect the protection stability. The results of on-site and laboratory investigations on protection stability have permitted to determine that the following reasons influence on the development of deformations: presence of objective inaccuracies and assumptions in the accepted calculated design schemes and dependencies for determination of protection parameters; lack of completeness in registration of conditions for wave formation and level regime of reservoirs; initial data and survey materials do not always provide true information about ground conditions for construction of bank protection facility; technological deviations while constructing structures and their protection. It has been ascertained that one of the characteristics determining a dynamic stability of banks and slopes in structures under conditions of the reservoirs in Belarus along with the above reasons is a composition of the eroded soil characterized, in particular, by a inhomogeneity coefficient of loose soil. A self-pavement effect identified during the study of protection stability and formed during destruction of a bank composed of loose soils with increased heterogeneity has made it possible to propose a method for protecting slopes and banks. On-site investigations and laboratory experiments have permitted to obtain empirical relationships for calculation of dynamic equilibrium profile with self-pavement of two types. The paper provides a calculation for combined slope protection consisting of rockfill and synthetic filter materials of increased strength.

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Crack ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Crack Theory ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

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