scholarly journals The use of simplified methods for designing according to EC6 and safety of masonry structures

2013 ◽  
Vol 12 (3) ◽  
pp. 013-020
Author(s):  
Wojciech Chruściel ◽  
Paweł Sulik
Keyword(s):  
Calculation Method ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Calculation Methods ◽  
Simplified Method

The article describes the calculation method of masonry walls loaded vertically according to PN-EN 1996-1-1 and PN-EN 1996-3. The Calculation method is given and the differences between Eurocode 6 and "old Polish standard" are indicated. Additionally, the differences between calculations according to exact and simplified method described in Eurocode 6 that show adverse consequences of the use of simplified method. The places (formulas and assumptions), which causes the discrepancies in calculation methods are pointed out in the study.

scholarly journals Influence of sunspaces on the heating demand in rooms – comparison of ISO 13790 calculation methods

2021 ◽  
Vol 20 (2) ◽  
pp. 069-082
Author(s):  
Magdalena Grudzińska
Keyword(s):  
Solar Radiation ◽  
Calculation Method ◽  
Energy Demand ◽  
Calculation Methods ◽  
Research Project ◽  
Solar Systems ◽  
Basic Assumptions ◽  
Radiation Distribution ◽  
Simplified Method ◽  
High Degree

The calculation method presented in ISO 13790 was developed during the research project PASSYS. It aimed to work out the way of estimating energy demand while taking into account different passive solar systems. The standard includes two calculation methods for sunspaces – a full and simplified method. They differ in terms of basic assumptions and the treatment of solar gains in the sunspace and conditioned rooms. There are some doubts about the interpretation of equations presented in the standard, especially when it comes to modelling the solar radiation distribution within the solar space. The paper presents a discussion on the basic hypotheses applied in full and simplified methods, together with the author’s suggestions regarding modifications to the ISO 13790 calculation methods. The modified methods allowed to satisfactorily predict the functioning of the exemplary sunspaces with a smaller area of glazed partitions and higher radiation absorptivity of the casing, that is spaces similar in terms of solar radiation utilisation to traditional living spaces. The phenomena typical for sunspaces with a high degree of glazing, such as the retransmission of reflected radiation, were not sufficiently taken into account in the calculation methods of the standard.

Multifunctional Textiles for Protection against Natural Hazards

2008 ◽  
Vol 56 ◽  
pp. 601-608 ◽  
Author(s):  
Donato Zangani
Keyword(s):  
Health Monitoring ◽  
Structural Damage ◽  
Monitoring Systems ◽  
Masonry Walls ◽  
Historic Buildings ◽  
Masonry Structures ◽  
Strong Earthquakes ◽  
Soil Structures ◽  
Earthquake Protection ◽  
Heavy Rainfalls

Textile structures are extensively used in construction in forms of geotextiles. The retrofitting of existing masonry walls and soil structures is particularly important for earthquake protection of historic buildings and protection of earthworks against landslides. Unreinforced masonry structures are highly vulnerable because being originally designed mainly for gravity loads they often cannot withstand the dynamic horizontal loads in case of strong earthquakes. Soil structures, such as embankments, are subjected to landslides after heavy rainfalls or during earthquakes. Hence the necessity to develop efficient methods for the retrofitting of existing masonry buildings and earthworks and of related monitoring systems to possibly prevent the structural damage. To solve the above issues new multifunctional textile structures are being developed for application in construction for the retrofitting of masonry structures and earthworks, integrating a combination of different functions, including structural health monitoring.

scholarly journals COMPARISON OF THREE CALCULATION METHODS OF ENERGY PERFORMANCE CERTIFICATES IN SLOVENIA

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Wadie Kidess
Keyword(s):  
Numerical Calculation ◽  
Energy Performance ◽  
Heat Losses ◽  
Calculation Methods ◽  
The Third ◽  
Simplified Method ◽  
Calculation Results ◽  
Thermal Bridges ◽  
Simplified Calculation ◽  
Family House

In order to get the authorization for issuing energy performance certificates in Slovenia, the expert candidate has to attend the prescribed course and pass the exam. The simplified method for heat losses calculation that is taught at this course neglects the thermal bridges, raising concerns whether the calculation results are reliable. In this paper we have compared three methods for calculation of thermal losses for a “typical” family house. The first is the above mentioned simplified calculation using a correctional factor; the second takes into account the thermal bridges, using linear thermal transmittances obtained by numerical calculation, and the third takes into account the thermal bridges, using default values for linear thermal transmittances. Noting that the second method returns the most exact values, we have found that the first method results are too large, yet still smaller than the third method results.

Crack width calculation methods for large-scale concrete structures for the Ferry-Free E39

2018 ◽  
Author(s):  
Reignard Tan ◽  
Terje Kanstad ◽  
Mette R. Geiker ◽  
Max A. N. Hendriks
Keyword(s):  
Cross Sections ◽  
Calculation Method ◽  
Crack Width ◽  
Large Scale ◽  
Concrete Structures ◽  
Calculation Methods ◽  
Empirical Formulas ◽  
Eurocode 2 ◽  
Semi Empirical

<p>Motivated by the establishment of a Ferry-Free E39 coastal highway route, crack width calculation methods for design of large-scale concrete structures are discussed. It is argued that the current semi-empirical formulas recommended by Eurocode 2 is inconsistent and overly conservative for cross sections with large bar diameters and covers. A suggestion to formulating a more consistent crack width calculation method is given.</p>

Solving Decommissioning and Abandonment Problems When Planning to Shear 9 5/8-inch Casing in a 13 5/8-inch × 10k RAM BOP

2021 ◽  
Author(s):  
David Earl Cain ◽  
Keith Albert Klopfenstein ◽  
James Robert McMullan
Keyword(s):  
Calculation Method ◽  
Shear Force ◽  
Statistical Treatment ◽  
The Novel ◽  
Test Results ◽  
Calculation Methods ◽  
Working Pressure ◽  
Lower Shear ◽  
Validation Testing ◽  
Force Pressure

Abstract A decommissioning and abandonment requirement to shear 9 5/8-inch casing in certain circumstances with a 13 5/8-inch × 10,000 psi rated working pressure, RWP, Shear RAM type blowout preventer, BOP, resulted in a need to develop a novel casing shear device and shear calculation method. Results of shear testing, future engineering planning guidance, the new shear calculation method, and comparison to legacy technology are included in this paper. Interaction with the end user to understand requirements, a five-step problem solving procedure, a basis of design process, materials justification, verification analysis, validation testing, and describing an improved shear operator force/pressure calculation are all described. Shear larger casing in the required and restrictive RAM BOP and well bore presented a problematic challenge. Equally, tubular fish size was required to support fishing extraction operations following shear. Validation test results exceeded requirements and resulted in the need for a new approach to the shear calculation method. The novel shear RAM geometry was developed utilizing shear calculation methods which were based on legacy considerations. API 16A shear validation procedures and two legacy shear calculation methods where employed. Shear calculations are used to anticipate the RAM BOP operator pressures required to shear a specific tubular. The larger than historically allowed casing size to be sheared in a 13 5/8-inch × 10,000 psi RAM BOP meant higher operator pressures were anticipated for each operator option. A Novel shear RAM geometry was developed as a design intent to lower shear force/pressure. There was an observation during validation testing that the geometry exceeded expectations to lower shear pressure significantly. This observation led to a conclusion that an improved shear calculation method was required for this application. This novel calculation method description / statistical treatment, test results, RAM design methods, and tabular shear engineering planning information are included in this paper. One additional requirement of the shear RAM geometry was to provide an upper and lower fish deformed surface which could be easily retrieved thru the 13 5/8-inch BOP bore. An additional observation was that the fish width requirement was achieved. The novel shear calculation method allows an engineer to precisely plan for bonnet actuation pressures when larger casing is sheared. The precise calculation of shear force/pressure also assists with BOP operator size and type selection. The engineer will gain casing size versus shear pressure for specific operator options in tabular format. Planners will gain insight into tubular fish deformation estimation allowing mitigation of tubular extraction risk during operations planning.

Study on Static Design Methods of Plain Steel Plate-Light Weight Concrete Hollow Composite Decks

2012 ◽  
Vol 166-169 ◽  
pp. 610-615
Author(s):  
Yong Yang ◽  
Kang An ◽  
Su Sheng Zeng ◽  
Jian Yang Xue
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Steel Plate ◽  
Flexural Rigidity ◽  
Design Methods ◽  
Light Weight ◽  
Calculation Methods ◽  
Direction Parallel ◽  
Light Weight Concrete ◽  
Calculation Results

Based on the experiment results of five plain steel plate-light weight concrete hollow deck specimens, the design methods of the composite decks which mainly including the calculation method of the bearing capacity and calculation method of the flexural rigidity were introduced. In the paper, the bearing capacity and flexural rigidity of the composite at two orthogonal directions, which including the direction parallel to the pipes and the direction perpendicular to the pipes, were both introduced. The calculation results of the bearing capacity and middle-span deflection were in good agreement with those of the experimental results, and in the return calculation methods were verified. Therefore, the design methods and calculation methods were useful to the design of this new type composite deck.

The Effects of Strengthening the AAC Walls Using Glass Mesh Arranged in Different Configurations

2019 ◽  
Vol 817 ◽  
pp. 442-449
Author(s):  
Marta Kałuża ◽  
Jan Kubica
Keyword(s):  
Residential Buildings ◽  
Natural Material ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Effective Solution ◽  
Modes Of Failure ◽  
Diagonal Compression ◽  
External Strengthening ◽  
Concrete Blocks ◽  
Aerated Concrete

The usage of AAC (Autoclaved Aerated Concrete) blocks for the construction of new masonry structures, particularly low-rise residential buildings, has become very popular in Poland. It provides an uncomplicated erecting method, which is characterized by thin bed joints and unfilled head joins, but at the same time, makes these walls very sensitive to any internal tensile stresses, causing damage with varying intensity. To avoid premature cracking, leading to a brittle failure of existing walls, an external strengthening can be an acceptable and effective solution. Taking into account that AAC units are a natural material, the application of a FRCM system (instead of FRP) is more suitable here. This system uses a mineral-based matrix that provides congenial compatibility with a masonry substrate.This study presents an analysis of the influence of superficial strengthening on the behaviour and deformability of masonry walls made of AAC blocks. A typical glass mesh (most often used in thin external plastering) and mineral mortar dedicated to renovation works are used as strengthening materials. The specimens are strengthened unilaterally (two types) or bilaterally and are subjected to diagonal compression according to the RILEM 76-LUM standard. The consecutive work stages, shear strains and modes of failure are described and discussed.

Seismic strengthening of masonry walls using bamboo components

2019 ◽  
Vol 22 (14) ◽  
pp. 2982-2997 ◽  
Author(s):  
Qingfeng Xu ◽  
Xi Chen ◽  
Jian-Fei Chen ◽  
Kent A Harries ◽  
Lingzhu Chen ◽  
...  
Keyword(s):  
Construction Industry ◽  
Cement Mortar ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Limit States ◽  
Green Material ◽  
Remote Areas ◽  
Externally Bonded ◽  
Reinforced Cement ◽  
Energy Dissipation Capacity

Bamboo is a sustainable green material and has been gradually applied in the construction industry; however, little research on strengthening masonry structures with bamboo has been carried out. In this article, strengthening methods using bamboo were developed including bamboo grid reinforced cement mortar layer, externally bonded bamboo mats, additional confining horizontal bamboo reinforced concrete band beams, and bamboo strips placed in mortar joints. Ten masonry walls were designed including two reference walls. Experimental results showed that all the strengthening methods can improve certain aspects of the seismic performance of masonry walls. The shear strength, deformability, and energy dissipation capacity of masonry walls strengthened with bamboo grid reinforced cement mortar and externally bonded bamboo mats were the most improved. The limit states of tested walls were discussed. Strengthened masonry structures with bamboo components are promising methods and can be used especially in remote areas.

scholarly journals Acoustic Emission Health Monitoring of Historical Masonry to Evaluate Structural Integrity under Incremental Cyclic Loading

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 508 ◽  
Author(s):  
Georgios Livitsanos ◽  
Naveen Shetty ◽  
Els Verstrynge ◽  
Martine Wevers ◽  
Danny Van Hemelrijck ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Velocity Distribution ◽  
Health Monitoring ◽  
Source Location ◽  
Pulse Velocity ◽  
In Situ Monitoring ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Velocity Measurements ◽  
Historical Masonry

Historical masonry structures during the decades, were composed with a variety of brick and mortar types according to materials availability of each region and the desirable mechanical properties in each specific case. Different composition of mortars leads to another masonry behavior, and each one is suited for different structural purposes. A crucial aspect in damage evaluation of masonry structures is the analysis of long-term behavior which has a great influence on safety assessment of these structures. In this study, cement, hybrid lime cement, hydraulic lime and lime hydrate mortars were assembled with solid red clay bricks to compose four masonry walls of dimensions 515 × 376 × 90 mm. They were tested under cyclic compression loading. Acoustic Emission (AE) allowed in situ monitoring of damage progression. AE is a powerful non-destructive technique applied to identify micro and macro-defects and their temporal evolution in several materials. This technique permits to estimate a variety of characteristics during fracture propagation to obtain information on the criticality of the ongoing process. Specifically, analyzing and comparing AE parameters among the loading cycles of each wall specimen and among the different masonry compositions, an integrity assessment can be achieved. Furthermore, in each loading and unloading step, pulse velocity measurements were conducted using the AE apparatus in order to gain a velocity distribution mapping among the sensors. Each sensor was pulsed in turn, with all other sensors acting as receivers, generating a velocity matrix from one sensor to another. This provided an insight into the damage severity of masonry walls with the increasing number of loading cycles. This measurement was also necessary for refining AE source location accuracy by using either the horizontal or the vertical velocity. Two different cases were investigated. The use of one uniform velocity for the whole masonry wall and the assumption that the velocity differs in the two vertical directions due to the heterogeneity of the structure. These two cases result in differences in the quantity and the position of the localized events. Furthermore, applying direct ultrasonic pulse velocity measurements, in the direction of the width of masonry walls, another integrity investigation was feasible. The presented results further demonstrate the relationships between AE parameter-based analysis, velocity distribution and source location during cyclic compressive loading in masonry specimens. The identification of the nature of damage through the entire dataset of all sensor arrays provides a promising example for structural health monitoring applications on larger scale masonry specimens. As a conclusion, AE activity analysis proved to be a very efficient approach to evaluate fracture progress in masonry.

Confidence assessment and interval prediction for multi-input model via grey system theory

2018 ◽  
Vol 8 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Haoliang Wang ◽  
Xiwang Dong ◽  
Qingdong Li ◽  
Zhang Ren
Keyword(s):  
Confidence Interval ◽  
Correlation Coefficient ◽  
Calculation Method ◽  
Reference Sample ◽  
Prediction Method ◽  
Calculation Methods ◽  
Content Type ◽  
Interval Prediction ◽  
Confidence Value ◽  
Reference Samples

Purpose By using small reference samples, the calculation method of confidence value and prediction method of confidence interval for multi-input system are investigated. The purpose of this paper is to offer effective assessing methods of confidence value and confidence interval for the simulation models used in establishing guidance and control systems. Design/methodology/approach In this paper, first, an improved cluster estimation method is proposed to guide the selection of the small reference samples. Then, based on analytic hierarchy process method, the new calculation method of the weight of each reference sample is derived. By using the grey relation analysis method, new calculation methods of the correlation coefficient and confidence value are presented. Moreover, the confidence interval of the sample awaiting assessment is defined. A new prediction method is derived to obtain the confidence interval of the sample awaiting assessment which has no reference sample. Subsequently, by using the prediction method and original small reference samples, Bootstrap resampling method is used to obtain more correlation coefficients for the sample to reduce the probability of abandoning the true. Findings The grey relational analysis is used in assessing the confidence value and interval prediction. The numerical simulations are presented to demonstrate the effectiveness of the theoretical results. Originality/value Based on the selected small reference samples, new calculation methods of the correlation coefficient and confidence value are presented to assess the confidence value of model awaiting assessment. The calculation methods of maximum confidence interval, expected confidence interval and other required confidence intervals are presented, which can be used in assessing the validities of controller and guidance system obtained from the model awaiting assessment.

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