Determination of partial factor for model uncertainty for unreinforced masonry shear walls

Mauerwerk ◽  
2018 ◽  
Vol 22 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Hamidreza Salehi
Keyword(s):  
Model Uncertainty ◽  
Shear Walls ◽  
Unreinforced Masonry ◽  
Partial Factor

scholarly journals Evaluation of seismic displacement demand for unreinforced masonry shear walls

2018 ◽  
Vol 5 (1) ◽  
pp. 1480189 ◽  
Author(s):  
Jayaprakash Vemuri ◽  
Syed Ehteshamuddin ◽  
Subramaniam V. L. Kolluru ◽  
Antonio Formisano
Keyword(s):  
Shear Walls ◽  
Unreinforced Masonry ◽  
Seismic Displacement ◽  
Displacement Demand

scholarly journals Reliability Verification of Unreinforced Masonry Wall

2016 ◽  
Vol 10 (6) ◽  
pp. 159
Author(s):  
Mahdi Montazerolghaem ◽  
Wolfram Jäger
Keyword(s):  
Reliability Analysis ◽  
Building Materials ◽  
Residential Buildings ◽  
Limit State ◽  
Shear Walls ◽  
Unreinforced Masonry ◽  
Major Influence ◽  
Reliability Level ◽  
Verification Methods ◽  
Reliability Verification

Unreinforced masonry (URM) is known as sustainable building material and is on the top of worldwide building materials consumed in residential buildings. The reliability level of a designed URM shear walls (URMW) has major influence on safety and cost of masonry constructions. Assessing the reliability level of different URMW is the purpose of this paper.The verification methods for combination of in-plane shear and compression according to the latest version of German National Annex of Eurocode 6are presented. The design models available in the code are rephrased and direct deterministic equations are introduced to predict the capacity. Limit State and Reliability Verification of URM Wall.On this base, several limit state are established and reliability analysis using crude Monte Carlo method are run. The effect of uncertainty on assessed reliability is highlighted. The distinction between linear and non-linear application of partial safety factors are assessed. The result of reliability analysis, based on the available probabilistic information on material with uncertainty models for designed URMW is presented in the article.The principal results are the actual reliability level found in the study regarding various masonry walls designed according to the latest German National Annex code DIN EN 1996-1-1 /NA: 2012-05 on different load situation. A review on the common target reliability index for structures according to different codes is done and the assessed reliability is compared with the target value.

scholarly journals Shear walls of limited ductility

1980 ◽  
Vol 13 (2) ◽  
pp. 144-161
Author(s):  
L. M. Robinson
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Design Method ◽  
Shear Walls ◽  
Strength Design ◽  
Earthquake Resistant ◽  
Heavy Damage ◽  
Suggested Classification ◽  
Classification And Treatment

The design and detailing of earthquake resistant reinforced concrete shear walls of limited ductility designed by a modified strength design method are discussed. Suitable methods for the evaluation of actions and the determination of internal actions
are advanced, having regard to energy dissipation and the consequences of heavy damage or of collapse. Discussion is not restricted to uniform walls, but is extended to walls with openings, for which a suggested classification and treatment is presented, thus allowing for suitable design techniques for walls transitional between uniform walls and frames to be determined. Applications 
of the proposals are illustrated in an Appendix.

Cell Network-Based Formulas for Fast Determination of Flexural Stiffness Reduction of U-Shaped Core Shear Walls

2018 ◽  
Vol 34 (2) ◽  
pp. 867-891
Author(s):  
Yicheng Yang ◽  
Sai Yemmaleni ◽  
Ikkyun Song ◽  
In Ho Cho
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Flexural Stiffness ◽  
Finite Element Analyses ◽  
Efficient Tool ◽  
Fast Determination ◽  
Cell Network ◽  
Stiffness Reduction ◽  
Unit Cells

Reinforced concrete (RC) core shear wall is one of the most widely used earthquake-resisting systems. Degradation of a core wall's flexural stiffness is vital for understanding the natural frequency shift of the damaged building. But it is hard to capture, often necessitating complex finite element analyses (FEAs). This study seeks to provide an efficient tool to quickly determine the remaining flexural stiffness of U-shaped core walls. Importantly, the tool is designed to require only the easy-to-collect observational damage information. Of primary novelty is a network of microscopic unit cells, each consisting of nonlinear concrete and steel springs along with a compression-only gap. Validations with three U-shaped walls tested under complex and multidirectional loading paths show that the proposed formulas appear promising in quickly determining the trend of degrading flexural stiffness compared with a high-precision multiscale FEA program. All the formulas written in Matlab codes are made publicly available. Using the portable formulas running on a laptop, practicing engineers and researchers will be able to swiftly diagnose core U-shaped walls after quick on-site or laboratory observations.

scholarly journals Experimental shear testing of timber-masonry dry connections for the seismic retrofit of unreinforced masonry shear walls

2019 ◽  
Vol 211 ◽  
pp. 52-72 ◽  
Author(s):  
Daniele Riccadonna ◽  
Ivan Giongo ◽  
Gianni Schiro ◽  
Ermes Rizzi ◽  
Maria Adelaide Parisi
Keyword(s):  
Shear Walls ◽  
Seismic Retrofit ◽  
Unreinforced Masonry ◽  
Shear Testing

Costs and Benefits of Seismic Upgrading of Some Buildings in the Boston Area

1985 ◽  
Vol 1 (4) ◽  
pp. 721-740 ◽  
Author(s):  
M. Elisabeth Paté-Cornell
Keyword(s):  
Reinforced Concrete ◽  
Advisory Committee ◽  
Shear Walls ◽  
Unreinforced Masonry ◽  
Building Codes ◽  
Masonry Buildings ◽  
Existing Buildings ◽  
Costs And Benefits ◽  
Market Effects ◽  
Additional Costs

We examine here the costs and benefits of reinforcing some existing buildings in Boston at the time of remodelling with significant change of use. The buildings of interest are the unreinforced masonry warehouses and the reinforced concrete manufacturing buildings that are remodelled into apartment or office buildings. Given some estimates of the Boston seismicity and of the performance of these buildings in earthquakes with and without additional reinforcement, we evaluate three possible levels of reinforcement that the Masssachusetts Seismic Advisory Committee could recommend as part of the building codes. For the unreinforced masonry buildings, the first upgrading level is the addition of floor and roof diaphragms, and the two subsequent levels involve addition of internal walls and reinforcement of the existing ones. For the reinforced concrete buildings, the first level involves increase of the shear walls' size, and higher upgrading levels involve addition of shear walls and increase of the columns' size. We introduce in our study the market effects of the additional costs. We conclude that only the first levels of reinforcement that we considered could be adopted as regulations, and that higher standards should be left to the choice of the buildings' occupants.

Model Uncertainties of FEM Nonlinear Analyses of Concrete Structures

2016 ◽  
Vol 249 ◽  
pp. 197-202 ◽  
Author(s):  
Lukáš Kadlec ◽  
Vladimir Červenka
Keyword(s):  
Numerical Simulations ◽  
Model Uncertainty ◽  
Structural Reliability ◽  
Constitutive Relations ◽  
Nonlinear Analyses ◽  
Model Uncertainties ◽  
Flexural Failure ◽  
Literary Sources ◽  
Near Future

Advanced numerical simulations are more often used due to the increasing possibilities of computer technology. For material descriptions, generally nonlinear constitutive relations are employed. It is expected that in the near future the reliability of structures will be assessed by use of these sophisticated calculations. For this purpose, it is firstly necessary to evaluate the model uncertainty of the numerical model, because the structural reliability is directly affected by the model uncertainty. Recommended values of model uncertainties differ in individual scientific literary sources. In standard codes the partial safety factor for model uncertainty is set by relatively low value. This value was assessed by empirical way and it seems that such value is valid only for flexural failure. Contemporary numerical simulations indicate larger model uncertainties. Moreover, the value of model uncertainty should be related to particular failure mode. This paper presents a comprehensive procedure for the determination of model uncertainties of nonlinear analyses. In the second part, the value of model uncertainties is derived for punching of slabs.

Sign in / Sign up

Export Citation Format

Share Document