scholarly journals Optimal ratio of spans of continuous bridges

2021 ◽  
Vol 263 ◽  
pp. 03001
Author(s):  
Aleksander Makarov ◽  
Sergey Kalinovsky ◽  
Natalia Ermilova ◽  
Alexey Churakov
Keyword(s):  
Building Materials ◽  
Bending Moments ◽  
Construction Work ◽  
Load Bearing Capacity ◽  
Reinforced Concrete Bridge ◽  
Bridge Span ◽  
Effective Efficiency ◽  
Bridge Spans ◽  
Cost Of Construction ◽  
Continuous Metal

The article deals with the creation of continuous metal and monolithic reinforced concrete bridge spans, which are the most effective. Efficiency is achieved by finding opportunities for the unification of structures with the most successful options for providing them with the required load-bearing capacity with the lowest cost of building materials. The bending moments that occur in the sections of a continuous structure are distributed more evenly and take on smaller values in the span than in a split structure. However, the efficiency of continuous structures can be further improved by introducing a certain coefficient of the length of the extreme spans of the bridge relative to the average ones. This allows you to achieve equality of the reference or span bending moments. As a result, the design will work in such a way that it will be possible to build the bridge span as if from three types of unified blocks, which will reduce the complexity and cost of construction work. As an example, in this case, the ratio of spans and the corresponding division into blocks for four-span continuous bridges are determined.

scholarly journals Unification in the design of four-span continuous bridges

2021 ◽  
Vol 18 (3) ◽  
pp. 120-126
Author(s):  
A. V. Makarov ◽  
◽  
S. A. Kalinovsky ◽  
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Concrete Bridge ◽  
Construction Work ◽  
Load Bearing Capacity ◽  
Reinforced Concrete Bridge ◽  
Bridge Span ◽  
The Cost ◽  
Cost Of Construction ◽  
Continuous Metal

The article deals with the creation of continuous metal and monolithic reinforced concrete bridge span structures, which are the most efficient. Efficiency is achieved by searching for opportunities to unify structures with the most successful options for providing them with the required load-bearing capacity with the lowest cost of building materials. If a certain coefficient of the length of the extreme relative to the average is introduced, there can be achieved the equality of the transverse moments of spans. Such performance of the structure will allow building the bridge span as if combined from three types of unified blocks, which would reduce the labor complexity and the cost of construction work.

scholarly journals Influence of natural and climatic factors on the organization of construction

2020 ◽  
Vol 164 ◽  
pp. 08006
Author(s):  
Marat Kuzhin ◽  
Ekaterina Chepik ◽  
Angelina Baranova
Keyword(s):  
Climatic Factors ◽  
Climatic Conditions ◽  
Technical Documentation ◽  
Construction Work ◽  
Natural Conditions ◽  
Factors Affecting ◽  
The Cost ◽  
Monolithic Structures ◽  
Cost Of Construction

In this research the influence of natural and climatic conditions on the organization of construction production are examined. Our purpose was to identify the nature of the dependence of the duration of construction work on natural and climatic factors. The analysis of normative and technical documentation in terms of accounting for the influence of natural and climatic factors was made. The system of estimation of influence of natural conditions on preparatory, ground, facade, roofing works, and also the appliance of monolithic structures, installation of prefabricated ferroconcrete items, and on works – implementation of internal finishing is offered. It was estimated, that the norms of construction production take into account a certain number of natural and climatic factors affecting the performance of work, but most of these factors have not yet been given in the normative and technical documentation. It is necessary to study this issue more comprehensively and to establish exact dependences on natural and climatic conditions, which will allow to quantify these factors already while calculating. This is necessary to compile more accurate calendar plans and schedules of production of works, as close as possible to real conditions. The study of this issue is one of the most important issues in the design of construction production. With insufficient consideration of these factors, the final actual figures are very different from the projected ones, which also lead to an increase in the cost of construction and installation work and the duration of their implementation. Taking into consideration the influence of natural and climatic factors will allow planning construction production more accurate.

scholarly journals Premature destruction of two-span RC beams exposed to high temperature caused by a redistribution of shear forces

2016 ◽  
Vol 23 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Robert KOWALSKI ◽  
Michał GŁOWACKI ◽  
Marian ABRAMOWICZ
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Bending Moment ◽  
Middle Part ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Bending Moments ◽  
Rc Beams ◽  
Shear Forces ◽  
Load Bearing Capacity

When multi-span RC elements are exposed to fire one usually observes a yielding of span cross-sections while a safety reserve of support cross-sections is still significant. Due to this phenomenon a redistribution of bending moments occurs and the values of sagging moment in span cross-sections decrease while the values of hogging moment in support cross-sections increase. This paper shows the results of tests conducted on two-span RC beams in a situation when only one span has been exposed to high temperature from the bottom. The beams were 12×16 cm in their cross-section. The length of the span was 165 cm. The load has been applied by two forces put on each span. The beams were made of C25/30 concrete with siliceous aggregate. As a result of significant stiffness decrease of the heated span, redistribution of shear forces and bending moment occurs. Due to this redistribution the tested beams were prematurely damaged due to exhaust of the shear load bearing capacity in the middle part of the beam span where there was no transverse reinforcement.

Development of Concretes with Resistance to High Temperatures in the Czech Republic and Surrounding European Countries

2013 ◽  
Vol 651 ◽  
pp. 120-125 ◽  
Author(s):  
Lenka Bodnárová ◽  
Jiri Zach ◽  
Jitka Hroudová ◽  
Jaroslav Válek
Keyword(s):  
Czech Republic ◽  
High Temperatures ◽  
Nuclear Power ◽  
Power Plants ◽  
Building Materials ◽  
European Countries ◽  
Terrorist Attacks ◽  
Load Bearing Capacity ◽  
The Czech Republic ◽  
The Stability

The resistance of concrete constructions to high temperatures at present is a much monitored issue for many scientific teams and experts in the stated area. This fact is mainly caused by fatal consequences originating in the case when concrete constructions are loaded by the effect of fire and consequent loss of their load-bearing capacity, for the population and the environment of our planet, in which we live in. The development of society goes hand in hand with the development of new building materials and as a consequence the requirements for building constructions increase which bring about extraordinary strict regulations in the area of fire safety. So, many high, non-traditional or specific constructions originate, e.g. nuclear power plants due to permanently higher demand for transport linkage and many tunnels have originated between European countries as a result. Unfortunately, in this relation the threat of terrorist attacks increases and unexpected natural disasters which also threaten the stability of the mentioned constructions. The objective of the article is to familiarize readers with the results of research concerning the improvement of the resistance of the concrete to high temperatures originated during fire instances.

scholarly journals The Future and Prospects of Periwinkle Composites in Reinforced Concretes: A Review

2021 ◽  
pp. 49-67
Author(s):  
Nkwoada Amarachi ◽  
Onyedika Gerald ◽  
Oguzie Emeka ◽  
Ogwuegbu Martin
Keyword(s):  
Building Materials ◽  
Construction Materials ◽  
Cementitious Materials ◽  
Economic Benefits ◽  
Concrete Technology ◽  
Naturally Occurring ◽  
Cost Of Construction ◽  
Shell Powder ◽  
Periwinkle Shell ◽  
Curing Age

The choice of building materials and the rising cost of construction materials have continued to plaque the building and construction industry without an immediate solution. Industrialists and scholars are investigating several naturally occurring materials for concrete composite reinforcements. The article chronologically reviewed the growth and development of periwinkle shell powder (PSP) and periwinkle ash powder (PSA) as composite materials in concretes. Findings showed that 28 days of curing age are required for lightweight concretes reinforced with PSP or PAP at 10-30% optimum. Produced lightweight concretes were susceptible to acidic medium and induce lower compressive strength which eventually leads to concrete/structure disintegrate and collapse. Research challenges and funding hamper the application of PSP/PAP in the concrete formulation and are unable to drive innovations and economic benefits as a composite. Advances in concrete technology showed that PSP/PSA mollusk shells achieve pillar strength grade and weight/load bearing status for the improvement of PSP/PSA blended concretes. Also, the composite potential showed that the functionalization of PSP/PSA, sustainability, and nano modification of cementitious materials and concretes are promising. Future studies are required to develop periwinkle reinforced concrete silos, sewers, and smart concrete materials with improved mechanical, thermal, and aesthetic properties.

scholarly journals Development of a cost controlling system for an investment and construction project

2021 ◽  
Vol 263 ◽  
pp. 05048
Author(s):  
Maria Bovsunovskaya
Keyword(s):  
Construction Projects ◽  
Building Materials ◽  
Construction Project ◽  
Banking System ◽  
Cost Controlling ◽  
Controlling System ◽  
General Contractors ◽  
The Russian Federation ◽  
The Cost ◽  
Cost Of Construction

The study is devoted to substantiating the need to develop a cost controlling system in order to improve the efficiency of investors, developers, customers, general contractors, as well as representatives of the banking system who are directly involved in the implementation of investment and construction projects. The paper summarizes the innovations of the Ministry of Construction, Housing and Utilities of the Russian Federation in the field of determining the cost of construction at the stages of the life cycle of an investment and construction project, and suggests their adaptation to the activities of commercial customers. The factors of the rise in the cost of construction in the modern conditions of the investment and construction sphere are systematized, including topical issues of the rise in cost due to the increase in prices of building materials. The main risks arising from the implementation of the project associated with an increase in cost are highlighted. As the results of the study, stages of construction cost control with a description of their content and a system of cost controlling of an investment and construction project are proposed.

scholarly journals Quality consideration of building and renovation works while forensic structural inspections to determine the volume and cost of construction

2021 ◽  
Vol 23 (1) ◽  
pp. 236-245
Author(s):  
T. Dudnyk ◽  
L. Chintea
Keyword(s):  
Building Codes ◽  
Construction Work ◽  
Field Surveys ◽  
Quality Of Work ◽  
Physical Volume ◽  
The Cost ◽  
Cost Of Construction ◽  
Construction Works

Currently, forensic methods and regulations in the field of construction do not explain how quality of work affects the procedure of forensic examinations and research related to determining the work scope. While carrying out building and renovation services, it is possible to control provided construction and renovation services,  establish their physical volume and quality. While research, forensic expert can identify violations of building codes, as well as determine the cost of refurbishment or elimination of defects made providing services. The scoop of performed works is determined by geometric parameters of construction elements, established during field surveys using design and as-built documentation. While carrying out field surveys, it is necessary (along with the determination of service scope) to pay attention to the compliance of the work performed with the requirements of building codes. The article outlines problematic issues and provides a list of basic indicators determining the scoop and quality of the construction works carried out, indicated in the reporting documentation drawn up by contractors based on results of activities in the field of construction. Actual issue arising in the establishment of the scoop and cost of construction work is considered  that quality does not meet the requirements of regulatory documents in the field of construction. It is explained how the quality of the work performed affects the results of research related to the determination of the actually completed volumes of repair, building and renovation and construction work.

scholarly journals PREVENTION OF METAL BRIDGE SPANS FROM FATIGUE CRACKING

2019 ◽  
Vol 21 (4) ◽  
pp. 181-193
Author(s):  
S. A. Bokarev ◽  
A. M. Usoltsev ◽  
A. I. Sluzhaev
Keyword(s):  
Fatigue Cracking ◽  
Crack Mouth ◽  
Railway Network ◽  
Residual Welding Stress ◽  
Welding Stress ◽  
Bridge Span ◽  
Metal Plates ◽  
Cracking Process ◽  
Bridge Spans ◽  
Further Development

At present, more than four thousand metal bridge spans are in operation all over the Russian railway network. Through the years of operation, about thirty types of fatigue cracking were identified. The dynamics of the types Т-9 and Т-10 cracks formation has increased significantly in recent years. The formation and growth of fatigue cracking is influenced by such factors as residual welding stress, stress-strain state of the bridge structure, defects, damages, and non-observing the operation and maintenance standards, bridge location and bridge span structure. At present, neither measures nor repair are performed to prevent fatigue cracking not exceeding 20 mm in length. Only when a creak reaches a certain length, the regulatory documents require to drill a hole at a crack mouth in order to prevent its further development. The hole diameter should be equal approximately to the doubled wall thickness. In order to prevent further crack growth and cover the hole, a high-tensile bearing type bolt is fixed into it, creating a volume stress. As a rule, such a repair is not enough to stop the cracking process. The article suggests a number of measures based on induction heating that allows to prevent cracking (including forging reducing gaps between connecting plates and horizontal sheets in a truss), to carry out repair (crack mouth soldering) and reinforcement (fixing metal plates onto a wall with a hole).

Probabilistic Assessment of Historic Reinforced Concrete Bridge

2016 ◽  
Vol 821 ◽  
pp. 767-773
Author(s):  
Jan Krejsa ◽  
Miroslav Sýkora ◽  
Michal Drahorád
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Probabilistic Method ◽  
Concrete Bridge ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Concrete Bridge ◽  
Factor Method ◽  
Partial Factor Method ◽  
Partial Factor

This paper is aimed at the reliability analysis of an existing reinforced concrete bridge from 1908. The load bearing capacity is assessed in accordance with valid standards using the partial factor method and probabilistic approach. Load bearing capacities obtained by these methods are critically compared. The application of probabilistic method leads to 40 % higher load bearing capacity then the partial factor method used for structural design.

scholarly journals Research on Intelligent Evaluation System of Load-bearing Capacity of Existing Reinforced Concrete Bridge

2020 ◽  
Vol 165 ◽  
pp. 04056
Author(s):  
An Zhao ◽  
Qiang Xu ◽  
Jianyong Song
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Evaluation System ◽  
Limit State ◽  
Concrete Bridge ◽  
Parametric Modelling ◽  
Limit States ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Concrete Bridge

The intelligent evaluation system of existing reinforced concrete bridge “BLP” is a special software for the load-bearing capacity rapid analysis and evaluation of the existing reinforced concrete bridge, which was developed by the Highway Research Institute of the Ministry of Transport. Based on the parametric modelling method, it can quickly and easily establish the finite element plane model of the bridge structure for the static analysis of ultimate bearing capacity limit states and serviceability limit state, under variety norms. And it can easily and quickly build variable-section beams and rebars, with the special module. According to the comprehensive modification method of the load-bearing capacity evaluation, it can automatically recommend checking sections, and automatically calculate partial modification coefficient of resistance effect, and conveniently judge the safety coefficient of the sections, and quickly get the results of bridge load-bearing capacity. In summary, this system can significantly improve the work efficiency and accuracy of load-bearing capacity for exiting reinforced concrete bridge. This paper introduces in detail the characteristics of the intelligent analysis technology, calculation principle and real bridge application examples of the system.

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