Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-95-113
N. Perminov, R. Mangushev
Long-term operation in difficult engineering-geological conditions of unique underground sewage facilities creates the danger of violating their structural safety. A long-term study of the dynamics of changes in a technical state of large pumping stations and deep sewage tunnels made it possible to establish patterns of influence of intensive anthropogenic and dynamic actions on this process. The developed discrete and continuous diagnostic models of defect development in tunnel structures allow identifying potentially hazardous areas subjected to manifestation of critical failures and methods of their localization. On the basis of numerical modeling the boundaries of defect-free joint operation of the system “source of impact – geo-mass – sewage underground structure” have been determined. The geotechnical and structural calculations are used to simulate the interaction of the facilities with the soil environment and predict adaptive stress-strain control system parameters. With increasing external anthropogenic and dynamic impacts, modeling zones of urban areas with potentially dangerous sections of underground sewage facilities constitute the basis for development of regulatory documents on monitoring methods and safe development of the geotechnical infrastructure of a megacity.
{"title":"MODELING AND MONITORING OF STRUCTURAL SAFETY OF LONG-OPERATING UNDERGROUND STRUCTURES OF THE SEWAGE SYSTEM IN THE CONDITIONS OF INCREASING ANTHROPOGENIC ACTIONS IN ORDER TO PROVIDE SUSTAINABLE LIFECYCLE OF ENGINEERING INFRASTRUCTURE OF THE MEGACITY (THE EXPERIENCE OF ST. PETERSBURG)","authors":"N. Perminov, R. Mangushev","doi":"10.22337/2587-9618-2022-18-3-95-113","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-95-113","url":null,"abstract":"Long-term operation in difficult engineering-geological conditions of unique underground sewage facilities creates the danger of violating their structural safety. A long-term study of the dynamics of changes in a technical state of large pumping stations and deep sewage tunnels made it possible to establish patterns of influence of intensive anthropogenic and dynamic actions on this process. The developed discrete and continuous diagnostic models of defect development in tunnel structures allow identifying potentially hazardous areas subjected to manifestation of critical failures and methods of their localization. On the basis of numerical modeling the boundaries of defect-free joint operation of the system “source of impact – geo-mass – sewage underground structure” have been determined. The geotechnical and structural calculations are used to simulate the interaction of the facilities with the soil environment and predict adaptive stress-strain control system parameters. With increasing external anthropogenic and dynamic impacts, modeling zones of urban areas with potentially dangerous sections of underground sewage facilities constitute the basis for development of regulatory documents on monitoring methods and safe development of the geotechnical infrastructure of a megacity.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77634540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-86-94
L. Kuzmina, Y. Osipov, M. Astakhov
During the construction of ground and underground structures, filtration of a liquid grout in loose soil makes it possible to strengthen the foundation and create underground waterproof partitions. A one-dimensional problem of filtering a bidisperse suspension in a homogeneous porous medium with size-exclusion particle capture mechanism is considered. The article is devoted to the calculation of the exact solution of the problem given as the upper limit of the integral with a singularity. The proposed bitwise search method for calculating integrals makes it possible to smooth out fluctuations of the solution near the singularity. Partial and total retention profiles are analyzed.
{"title":"ANALYSIS OF THE FILTRATION PROBLEM BY BITWISE SEARCH METHOD","authors":"L. Kuzmina, Y. Osipov, M. Astakhov","doi":"10.22337/2587-9618-2022-18-3-86-94","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-86-94","url":null,"abstract":"During the construction of ground and underground structures, filtration of a liquid grout in loose soil makes it possible to strengthen the foundation and create underground waterproof partitions. A one-dimensional problem of filtering a bidisperse suspension in a homogeneous porous medium with size-exclusion particle capture mechanism is considered. The article is devoted to the calculation of the exact solution of the problem given as the upper limit of the integral with a singularity. The proposed bitwise search method for calculating integrals makes it possible to smooth out fluctuations of the solution near the singularity. Partial and total retention profiles are analyzed.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"22 8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88558287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-78-85
V. Sidorov, Elena Detina, E. Badina
The article presents numerical methods for controlling the parameters of temporal nonlocality of computer models of rod structures made of composite materials. The finite element method is the most widely used numerical method for solving practical problems of the analysis of mechanical systems. A nonlocal in time internal damping model is integrated into the algorithm of this method. The one-dimensional model of the Euler-Bernoulli beam is presented in the article. The equilibrium equation of a moving mechanical system is solved numerically using an implicit scheme. In the article the damping matrix obtained from the condition of stationarity of the total deformation energy was used. The article presents the study of non-local in time damping model properties. The model is integrated into the finite element method. The non-local model is algorithmized and programmed in the MATLAB software package.
{"title":"СONTROL OF A NONLOCAL IN TIME FINITE ELEMENT MODEL OF THE DYNAMIC BEHAVIOR OF A COMPOSITE BEAM BASED ON THE RESULTS OF A NUMERICAL EXPERIMENT","authors":"V. Sidorov, Elena Detina, E. Badina","doi":"10.22337/2587-9618-2022-18-3-78-85","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-78-85","url":null,"abstract":"The article presents numerical methods for controlling the parameters of temporal nonlocality of computer models of rod structures made of composite materials. The finite element method is the most widely used numerical method for solving practical problems of the analysis of mechanical systems. A nonlocal in time internal damping model is integrated into the algorithm of this method. The one-dimensional model of the Euler-Bernoulli beam is presented in the article. The equilibrium equation of a moving mechanical system is solved numerically using an implicit scheme. In the article the damping matrix obtained from the condition of stationarity of the total deformation energy was used. The article presents the study of non-local in time damping model properties. The model is integrated into the finite element method. The non-local model is algorithmized and programmed in the MATLAB software package.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"1211 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85232968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-126-136
A. Chepurnenko, G. Nesvetaev, Yuliya Koryanova, B. Yazyev
The article proposes the simplified method for determining stresses in massive monolithic foundation slabs arising from the heat release of concrete during the hardening process. The proposed technique makes it possible to reduce a three-dimensional problem to a one-dimensional one based on the features of the distribution of stresses and strains in the structures under consideration, identified during finite element modeling in a three-dimensional setting. The resulting resolving equations take into account the creep and shrinkage of concrete, the coefficient of reinforcement of the structure. The strength and deformation characteristics of concrete are assumed as functions of the degree of maturity of the concrete, which in turn is determined by the time and temperature of curing. Approbation of the developed model is carried out by comparison with the calculation in a three-dimensional setting in the ANSYS software package. The influence of creep and contraction shrinkage of concrete, the degree of concrete maturity and the coefficient of reinforcement on the stress-strain state of structures is investigated.
{"title":"SIMPLIFIED MODEL FOR DETERMINING THE STRESS-STRAIN STATE IN MASSIVE MONOLITHIC FOUNDATION SLABS DURING CONSTRUCTION","authors":"A. Chepurnenko, G. Nesvetaev, Yuliya Koryanova, B. Yazyev","doi":"10.22337/2587-9618-2022-18-3-126-136","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-126-136","url":null,"abstract":"The article proposes the simplified method for determining stresses in massive monolithic foundation slabs arising from the heat release of concrete during the hardening process. The proposed technique makes it possible to reduce a three-dimensional problem to a one-dimensional one based on the features of the distribution of stresses and strains in the structures under consideration, identified during finite element modeling in a three-dimensional setting. The resulting resolving equations take into account the creep and shrinkage of concrete, the coefficient of reinforcement of the structure. The strength and deformation characteristics of concrete are assumed as functions of the degree of maturity of the concrete, which in turn is determined by the time and temperature of curing. Approbation of the developed model is carried out by comparison with the calculation in a three-dimensional setting in the ANSYS software package. The influence of creep and contraction shrinkage of concrete, the degree of concrete maturity and the coefficient of reinforcement on the stress-strain state of structures is investigated.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86749614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-65-77
V. Galishnikova, T. Gebre
Thin-walled structures are widely used in various structural engineering applications due to their advantage of high bearing strength when compared to self-weight and used in a complex loading situation where subjected to combined loadings. When a thin-walled section is subjected to a combined load with restrained torsion, they are ineffective at resisting, resulting in a reduction in beam capacity due to torsion and additional warping stresses. A finite element calculation can be used to analyze a 3D bar of thin-walled structural sections. Different commercial software and studies commonly consider six degrees of freedom at each node of a member for a space frame without considering the effect of warping restraint at the member's ends. This paper presents a finite element calculation for thin-walled sections with restrained torsion using the 14x14 member stiffness matrix, which includes warping as an additional degree of freedom and is commonly used for open thin-walled sections. In this study, we considered two different methods for including the additional degree of freedom for the stiffness matrix, which are very close to each other for small values of characteristics number.
{"title":"FINITE ELEMENT ANALYSIS FOR THIN-WALLED MEMBER SUBJECTED TO COMBINED LOADING","authors":"V. Galishnikova, T. Gebre","doi":"10.22337/2587-9618-2022-18-3-65-77","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-65-77","url":null,"abstract":"Thin-walled structures are widely used in various structural engineering applications due to their advantage of high bearing strength when compared to self-weight and used in a complex loading situation where subjected to combined loadings. When a thin-walled section is subjected to a combined load with restrained torsion, they are ineffective at resisting, resulting in a reduction in beam capacity due to torsion and additional warping stresses. A finite element calculation can be used to analyze a 3D bar of thin-walled structural sections. Different commercial software and studies commonly consider six degrees of freedom at each node of a member for a space frame without considering the effect of warping restraint at the member's ends. This paper presents a finite element calculation for thin-walled sections with restrained torsion using the 14x14 member stiffness matrix, which includes warping as an additional degree of freedom and is commonly used for open thin-walled sections. In this study, we considered two different methods for including the additional degree of freedom for the stiffness matrix, which are very close to each other for small values of characteristics number.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76534209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.22337/2587-9618-2022-18-3-14-24
P. Gaydzhurov, N. Tsaritova, A. Kurbanov, Anastasia Kurbanova, E. Iskhakova
The process of forming new architectural solutions in the field of regular frame-rod systems necessitates the development of the concept of creating original spatial structures through the directed transformation of kinematically changeable truss-type objects. The article presents a numerical study of kinematic parameters during the gradual shaping of a rod system, which in its initial state is a flat hinge-rod network of repeating fragments in the form of equilateral triangles. The controlled kinematic effect on the object was modeled using actuators that were placed on the peripheral sections of the studied grids. The wide variability of the hinge-rod forms, the economical installation process using the principle of "self-extension" allow us to speak about the relevance of research in this direction.
{"title":"NUMERICAL SIMULATION OF THE PROCESS OF DIRECTED TRANSFORMATION OF A REGULAR HINGE-ROD SYSTEM","authors":"P. Gaydzhurov, N. Tsaritova, A. Kurbanov, Anastasia Kurbanova, E. Iskhakova","doi":"10.22337/2587-9618-2022-18-3-14-24","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-3-14-24","url":null,"abstract":"The process of forming new architectural solutions in the field of regular frame-rod systems necessitates the development of the concept of creating original spatial structures through the directed transformation of kinematically changeable truss-type objects. The article presents a numerical study of kinematic parameters during the gradual shaping of a rod system, which in its initial state is a flat hinge-rod network of repeating fragments in the form of equilateral triangles. The controlled kinematic effect on the object was modeled using actuators that were placed on the peripheral sections of the studied grids. The wide variability of the hinge-rod forms, the economical installation process using the principle of \"self-extension\" allow us to speak about the relevance of research in this direction.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83163792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-131-142
A. Alekseytsev, Al Ali Mohamad
An approach to solving the urgent problem of optimizing the load-bearing structures of buildings and structures based on adapted genetic algorithms is presented. As a tool for finding a solution, iterative schemes are used, in which, in the classical approach to evolutionary modeling, a system of constraints is used that forms the operational requirements for reinforced concrete, steel and other structures. In this case, the value of the risk of material losses is used as one of the measures of the design optimality. This value is used to assess the feasibility of increasing the initial costs of manufacturing structures, taking into account the degree of their mechanical safety in case of emergency impacts. Groups of scenarios are considered as such impacts, including local damage to one or more load-bearing elements. A limitation is formed on the resistance to progressive collapse of the structure, which is interpreted as preventing large displacements and limiting deformations of certain parts or the structure as a whole. The magnitude of the risk is determined by a relative index determined as the ratio of the likely cost for damage from material loss to the initial cost of manufacturing the structure. The block diagrams that implement such iterative processes, information about the developed software and an example of optimization of the reinforced concrete supporting structure of the frame of an administrative multi-storey building are considered.
{"title":"OPTIMIZATION OF BEARING STRUCTURES SUBJECT TO MECHANICAL SAFETY: AN EVOLUTIONARY APPROACH AND SOFTWARE","authors":"A. Alekseytsev, Al Ali Mohamad","doi":"10.22337/2587-9618-2022-18-2-131-142","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-131-142","url":null,"abstract":"An approach to solving the urgent problem of optimizing the load-bearing structures of buildings and structures based on adapted genetic algorithms is presented. As a tool for finding a solution, iterative schemes are used, in which, in the classical approach to evolutionary modeling, a system of constraints is used that forms the operational requirements for reinforced concrete, steel and other structures. In this case, the value of the risk of material losses is used as one of the measures of the design optimality. This value is used to assess the feasibility of increasing the initial costs of manufacturing structures, taking into account the degree of their mechanical safety in case of emergency impacts. Groups of scenarios are considered as such impacts, including local damage to one or more load-bearing elements. A limitation is formed on the resistance to progressive collapse of the structure, which is interpreted as preventing large displacements and limiting deformations of certain parts or the structure as a whole. The magnitude of the risk is determined by a relative index determined as the ratio of the likely cost for damage from material loss to the initial cost of manufacturing the structure. The block diagrams that implement such iterative processes, information about the developed software and an example of optimization of the reinforced concrete supporting structure of the frame of an administrative multi-storey building are considered.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86813143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-163-174
A. Tamrazyan, Andrey Lapshinov
The article discusses the relevance of developing techniques for confined elements with FRP reinforcement. The method for calculating centrally confined concrete columns with non-metallic GFRP reinforcement (without regard to its compression work) is proposed for the first time in the Russian Federation. The strength model was developed based on the well-known theoretical model of confined concrete. The article considers the effect of strengthening the concrete core of the columns, which is obtained due to the more frequent placement of both transverse and longitudinal reinforcement. The dependence of the bearing capacity of concrete columns on the strength of the transverse reinforcement material is shown. It was proved that with a decrease in the spacing of the longitudinal reinforcement, the area of the effectively confined concrete core inside the reinforcement cage increases. It was shown that, due to the low compressive modulus of elasticity of the FRP reinforcement, the stress in it will be comparable to the concrete stress. Therefore, the compressive strength of the FRP reinforcement can be neglected in the case of determining the bearing capacity of centrally confined concrete elements. As a result, a strength model for calculating confined concrete elements with FRP reinforcement was proposed, considering the spacing of transverse reinforcement, the longitudinal and transverse reinforcement ratio, and the strength of the material of transverse reinforcement. The developed strength model can be applied not only for square, but also for columns of round and rectangular sections.
{"title":"STRENGTH MODEL FOR CALCULATING CENTRALLY COMPRESSED CONCRETE ELEMENTS WITH COMPOSITE REINFORCEMENT, TAKING INTO ACCOUNT THE SPACING OF STIRRUPS","authors":"A. Tamrazyan, Andrey Lapshinov","doi":"10.22337/2587-9618-2022-18-2-163-174","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-163-174","url":null,"abstract":"The article discusses the relevance of developing techniques for confined elements with FRP reinforcement. The method for calculating centrally confined concrete columns with non-metallic GFRP reinforcement (without regard to its compression work) is proposed for the first time in the Russian Federation. The strength model was developed based on the well-known theoretical model of confined concrete. The article considers the effect of strengthening the concrete core of the columns, which is obtained due to the more frequent placement of both transverse and longitudinal reinforcement. The dependence of the bearing capacity of concrete columns on the strength of the transverse reinforcement material is shown. It was proved that with a decrease in the spacing of the longitudinal reinforcement, the area of the effectively confined concrete core inside the reinforcement cage increases. It was shown that, due to the low compressive modulus of elasticity of the FRP reinforcement, the stress in it will be comparable to the concrete stress. Therefore, the compressive strength of the FRP reinforcement can be neglected in the case of determining the bearing capacity of centrally confined concrete elements. As a result, a strength model for calculating confined concrete elements with FRP reinforcement was proposed, considering the spacing of transverse reinforcement, the longitudinal and transverse reinforcement ratio, and the strength of the material of transverse reinforcement. The developed strength model can be applied not only for square, but also for columns of round and rectangular sections.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88973733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-143-155
K. Sharafutdinov, K. Saraykina, G. Kashevarova, V. Erofeev
Experimental studies of the resistance of cement stone and concrete to the influence of mold fungi have been carried out. The effectiveness of the use of nanomodified calcium carbonate and the PHMG biocide as bactericidal additives for concrete has been investigated. The influence of Glenium and C-3 plasticizers on the effectiveness of the action of bactericidal additives has been investigated. Both investigated biocidal additives showed a fungicidal effect on concrete specimens. The use of nanomodified calcium carbonate as a bactericidal additive for concrete is effective as the use of PHMG biocide. The introduction of this bactericidal additives does not reduce the strength of the hardened concrete.
{"title":"THE USE OF COPPER NANOMODIFIED CALCIUM CARBONATE AS A BACTERICIDAL ADDITIVE FOR CONCRETE","authors":"K. Sharafutdinov, K. Saraykina, G. Kashevarova, V. Erofeev","doi":"10.22337/2587-9618-2022-18-2-143-155","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-143-155","url":null,"abstract":"Experimental studies of the resistance of cement stone and concrete to the influence of mold fungi have been carried out. The effectiveness of the use of nanomodified calcium carbonate and the PHMG biocide as bactericidal additives for concrete has been investigated. The influence of Glenium and C-3 plasticizers on the effectiveness of the action of bactericidal additives has been investigated. Both investigated biocidal additives showed a fungicidal effect on concrete specimens. The use of nanomodified calcium carbonate as a bactericidal additive for concrete is effective as the use of PHMG biocide. The introduction of this bactericidal additives does not reduce the strength of the hardened concrete.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90751685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-85-97
V. Selyaev, Sergey Gryaznov, D. Babushkina
The article solves the problem of determining the deflections of a beam made of a nonlinearly deformable material - a polyester composite held in water using the numerical methods of Ritz-Timoshenko and finite differences. The influence of the aggressive environment on the material of the structure was taken into account by introducing the degradation function of the stiffness of the element cross-sections into the calculation algorithms of the above methods. The problem of determining the time and conditions for the onset of the limiting state of the structure in the second group in accordance with the current norms and rules has been solved.
{"title":"DETERMINATION OF BENDING OF A BEAM FROM A NONLINEAR DEFORMABLE MATERIAL BY RITZ-TIMOSHENKO METHODS AND FINITE DIFFERENCES TAKING INTO ACCOUNT DEGRADATION FUNCTIONS OF CROSS SECTION RIGIDITY","authors":"V. Selyaev, Sergey Gryaznov, D. Babushkina","doi":"10.22337/2587-9618-2022-18-2-85-97","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-85-97","url":null,"abstract":"The article solves the problem of determining the deflections of a beam made of a nonlinearly deformable material - a polyester composite held in water using the numerical methods of Ritz-Timoshenko and finite differences. The influence of the aggressive environment on the material of the structure was taken into account by introducing the degradation function of the stiffness of the element cross-sections into the calculation algorithms of the above methods. The problem of determining the time and conditions for the onset of the limiting state of the structure in the second group in accordance with the current norms and rules has been solved.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87804685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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