scholarly journals MODEL TESTS ON COLLAPSE BEHAVIOR OF MASONRY WALLS, "TSUKIISHIBU", UNDER LONG-TERM LOAD

2007 ◽  
Vol 72 (619) ◽  
pp. 89-95 ◽  
Author(s):  
Takeshi MASUI ◽  
Shintaro YAO
Keyword(s):  
Model Tests ◽  
Masonry Walls ◽  
Collapse Behavior

Model Tests on the Long-Term Dynamic Performance of Offshore Wind Turbines Founded on Monopiles in Sand

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Zhen Guo ◽  
Luqing Yu ◽  
Lizhong Wang ◽  
S. Bhattacharya ◽  
G. Nikitas ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbines ◽  
Model Tests ◽  
Offshore Wind ◽  
Frequency Change ◽  
Test Results ◽  
Scaled Model ◽  
Structural Dynamic ◽  
Offshore Wind Turbines

The dynamic response of the supporting structure is critical for the in-service stability and safety of offshore wind turbines (OWTs). The aim of this paper is to first illustrate the complexity of environmental loads acting on an OWT and reveal the significance of its structural dynamic response for the OWT safety. Second, it is aimed to investigate the long-term performance of the OWT founded on a monopile in dense sand. Therefore, a series of well-scaled model tests have been carried out, in which an innovative balance gear system was proposed and used to apply different types of dynamic loadings on a model OWT. Test results indicated that the natural frequency of the OWT in sand would increase as the number of applied cyclic loading went up, but the increasing rate of the frequency gradually decreases with the strain accumulation of soil around the monopile. This kind of the frequency change of OWT is thought to be dependent on the way how the OWT is cyclically loaded and the shear strain level of soil in the area adjacent to the pile foundation. In this paper, all test results were plotted in a nondimensional manner in order to be scaled up to predict the consequences for prototype OWT in sandy seabed.

scholarly journals Discrete Model for the Collapse Behavior of Unreinforced Random Masonry Walls

2017 ◽  
Vol 747 ◽  
pp. 3-10 ◽  
Author(s):  
Daniele Baraldi ◽  
Antonella Cecchi
Keyword(s):  
Discrete Model ◽  
Yield Criterion ◽  
Elastic Field ◽  
Perturbation Parameter ◽  
Material Nonlinearity ◽  
Masonry Walls ◽  
Joint Level ◽  
Random Texture ◽  
Local Arrangement ◽  
Collapse Behavior

A discrete model with rigid blocks and elastic-plastic interfaces is adopted for studying the collapse behavior of in-plane loaded masonry panels with random texture. An existing random discrete model, originally developed in the elastic field, is here extended to the field of material nonlinearity by adopting a Mohr-Coulomb yield criterion for restraining actions at joint level. The resulting model turns out to be simple and effective in determining collapse loads and mechanisms of rectangular masonry panels, also accounting for a further perturbation parameter able to vary the height of each course of blocks into the masonry panel. The collapse loads turn out to be slightly smaller than those typical of regular assemblages, whereas mechanisms turn out to be influenced by local arrangement and size of blocks.

scholarly journals Long term in situ measurements of hygrothermal conditions at critical points in four cases of internally insulated historic solid masonry walls

2018 ◽  
Vol 172 ◽  
pp. 235-248 ◽  
Author(s):  
Tessa Kvist Hansen ◽  
Søren Peter Bjarløv ◽  
Ruut Hannele Peuhkuri ◽  
Maria Harrestrup
Keyword(s):  
Critical Points ◽  
In Situ Measurements ◽  
Masonry Walls

Creep Behaviour of Reinforced Masonry Walls by CFRP Sheets and Structural Mortar

2010 ◽  
Vol 452-453 ◽  
pp. 125-128
Author(s):  
Paola Antonaci ◽  
Pietro G. Bocca ◽  
Davide Masera
Keyword(s):  
Ad Hoc ◽  
Creep Behaviour ◽  
Masonry Walls ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Reinforced Masonry ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
Non Destructive

An experimental analysis on a set of strengthened masonry walls has been carried out by means of cyclic loading tests in order to simulate the creep effects. Laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino: ad hoc brickwork specimens were manufactured and reinforced by FRP and strengthening mortar. The main goal of this experimental work is to demonstrate that in the choice of the masonry reinforcement is important to value not only the increment of the ultimate strength of the material reinforced, but also its response and durability in term of long-term action, called as creep phenomenon.

Long Term Analysis for Estimation of Wave Slamming Pressures for Spar Design

2015 ◽  
Author(s):  
Ho-Joon Lim ◽  
Gunnar Lian ◽  
Sverre Haver ◽  
Oddgeir Dalane ◽  
Bonjun Koo ◽  
...  
Keyword(s):  
Model Tests ◽  
Design Parameters ◽  
Exceedance Probability ◽  
Extreme Wave ◽  
Short Term ◽  
Sea State ◽  
Norwegian Sea ◽  
Wave Slamming ◽  
Term Analysis

A long term analysis was performed to determine extreme wave slamming loads on the Aasta Hansteen Spar, the first production and storage Spar to be installed in the Norwegian Sea. The Spar will experience high slamming pressures on the hull due to harsh environments in the field. Extensive model tests were performed to measure the wave slamming pressure which is one of challenging design parameters. The slamming loads were measured with a 3×3 array of force transducer panels attached to the Spar hull. The extreme slamming loads were estimated from 3-hour simulations of the 100-yr and 10000-yr wave environments at the Aasta Hansteen field in the Norwegian Sea. The wave simulations included fourteen sea states, and each sea state was represented by as many as 20 realizations. Based on model test data, short term analysis of 3-hour extreme pressure at each tested sea state was performed using the Gumbel distribution. Due to high variability of 3-hour maximum pressures, a long term analysis was required to investigate the proper percentile level to be used in the design. The paper presents a long term statistical methodology for extreme wave slamming loads that is used to calculate long term slamming pressures corresponding to a specified annual exceedance probability of q (e.g., q = 10−2 and q = 10−4). The paper also derives the appropriate non-exceedance probability for a short term wave environment that reproduces the long term pressures of a specified annual exceedance probability, q. Various sensitivity analyses (e.g., on the two Gumbel parameters, number of realizations, etc.) were performed to validate the short term target percentiles and associated extreme pressures derived from this approach. Details of the model tests and methodology to define the design pressure profile above mean water level (MWL) are presented in a companion paper of this Conference.

scholarly journals Development of an Outdoor Wave Basin to Conduct Long-Term Model Tests with Real Vegetation for Green Coastal Infrastructures

2019 ◽  
Vol 7 (1) ◽  
pp. 18 ◽  
Author(s):  
Jochen Michalzik ◽  
Sven Liebisch ◽  
Torsten Schlurmann
Keyword(s):  
Ecosystem Services ◽  
Current Trend ◽  
Model Tests ◽  
Water Levels ◽  
Growth Stages ◽  
Wave Load ◽  
Ecological Value ◽  
Wave Basin ◽  
Sea Dikes

The demand for physical model tests with real vegetation is increasing due to the current trend to elucidate the performance and durability of green coastal infrastructures to ensure and promote ecosystem services. To address this demand, a new outdoor wave basin (OWB) was built in August 2017 at the Ludwig-Franzius-Institute in Hannover, Germany. This paper reviews the general characteristics and the ongoing development of the new OWB. First insights into the long-term development of the ecosystem services of different grass revetments are discussed in terms of their ecological value and safety standards of sea dikes. Focus is placed on the resistance and ecological value of different grass mixtures that are typically applied on sea dikes situated along the North Sea. Further research concepts are briefly described to highlight how experiments in the new OWB may contribute to the current understanding and design recommendations of green coastal infrastructures. The operation of the OWB enables the performance of long-term experiments over seasonal growth stages of coastal vegetation using either fresh or seawater with wave load stresses and varying sea water levels. The first conducted experiments with different grass revetment combinations mimic typical storm surge conditions with a constant wave load (with a duration of up to 10 hours every second week) on a natural dike.

EVALUATION OF APPLIED REMEDIATION WORKS ON HISTORICAL MASONRY WALL EXPOSED TO LONG-TERM DETERIORATION

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Jan Fořt ◽  
Zbyšek Pavlík ◽  
Lukáš Balík ◽  
Robert Černý
Keyword(s):  
Relative Humidity ◽  
Masonry Wall ◽  
Climatic Conditions ◽  
Time Domain Reflectometry ◽  
Masonry Walls ◽  
Moisture Movement ◽  
Historical Masonry ◽  
Residential House ◽  
Indoor And Outdoor

The exposure of massive historical masonry walls to varying climatic conditions represents a crucial factor for long-term damage related to moisture and soluble salts increase. Moisture movement in the porous structure of massive historical masonry wall driven by capillary forces is usually connected with transport of salt solutions, which can be responsible for a severe damage. Because of missing damp-proof insulation layers, the moisture ingress carrying soluble salt from the ground especially during winter periods is not prevented from. This study is aimed on the evaluation of the effect of commonly used restoration works on the conservation of an exposed building. The influence of applied precautions was continuously monitored by time-domain reflectometry probes in various depths and heights of the studied masonry wall located in the basement of a residential house in Prague, Czech Republic. Based on the obtained results, taking into account also the influence of indoor and outdoor temperature and relative humidity variations monitored by combined temperature/relative humidity sensors, the wall drying process and the success of applied methods is analyzed.

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