• Structural Engineering and Mechanics
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• v.87 no.4
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• pp.317-332
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• 2023

Understanding and analysing the behaviour and response of historical structures in the face of climate changes and environmental conditions is of utmost significance for their preservation. There are several structural hazards associated with climate and hydrology changes in the region, including the settlement of piers, the rotation of piers, and temperature changes. The present study investigates the experimental and numerical structural behaviour of skewed and non-skewed Persian brick masonry barrel vaults under various conditions. The external loading conditions included pier rotation in five modes, settlement, and temperature variations in four states. Initially, the experiments extracted the mechanical properties of the scaled materials. Then, three semi-circular brick barrel vaults were tested with gravitational loads. The outcomes were used to develop and validate the finite element model. Following the development of the finite element model, numerical and parametric studies were conducted on the effect of the aforementioned structural hazards on the response of brick masonry barrel vaults with various Persian geometries (semi-circular, drop pointed, and four-centred), angles of skew (0, 15, 30, and 45 degrees), and dimensional ratios. According to the findings, the fragility of masonry materials makes historical structures susceptible to failure under different loading. A brick barrel vault fails in the presence of minor rotation and settlement of the piers. The four-centred geometric shape has the lowest performance among the seven Persian geometries; therefore, its health monitoring and retrofitting should be prioritised. In Isfahan, Iran, temperature variations, particularly during the warm seasons, cause critical conditions in such structures.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.113-120
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• 1999

Deep excavation,1 in the urban areas may cause terrible damages to the adjacent structures. Most damages are due to the settlement of ground during excavation work. This article introduces two actual examples of structure damage in subway construction projects. A through of attempts to find out the factors that are affecting to the settlement of ground was made through site investigations and analyses of measurement data. Some suggestions are given to prevent the repeat of trial and error in deep excavation projects. This kind of attempts are eccentrical to the development and improvement of information-oriented construction method.

• Journal of Ocean Engineering and Technology
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• v.21 no.5
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• pp.25-32
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• 2007

The piled-raft foundation, a new design concept, is one of the most effective kinds of foundation for reducing settlement of structures. An alternative piled-raft system with disconnection cap and a sand cushion between the pile and raft was also investigated to compare the influence of ultimate bearing capacity and settlement. Load-settlement relation curves were used to evaluate the ultimate bearing capacity. In the numerical analyses, a plane strain elasto-plastic finite element model (Mohr-Coulomb model) was used to present the response of the piled-raft foundation.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.1-8
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• 2003

The development of environmentally nontoxic or non-polluting antifouling additives that can be formulated in practical coating requires assay involving target organisms. Described here are the simple laboratory assays that have been developed using the barnacle, Balanus amphitrite, a common fouling organism found throughout temperate and tropical seas. One of the assays depends on synchronous year-round mass culture, the procedure for which is described, of nauplii larvae and cyprids larvae. The laboratory assays provided quantitative estimates of toxicity and settlement inhibition of the test compounds. Laurinterol (1), isolaurinterol (2), alpysinal (3), and aplysin (4) have been isolated from the Korean red alga Laurencia okamurae. Their structures were identified by spectral data in comparison with the literature data. Compounds 1-4 inhibited larval settlement of the barnacle B. amphitrite with EC$_{50}$ values of 0.18- 36 $\mu\textrm{g}$/ml. Com-pounds 2-4 showed larval toxicity against nauplii of the barnacle B. amphitrite with 5-10 $\mu\textrm{g}$/ml, while laurinterol (1) exhibited no toxicity at even 100 $\mu\textrm{g}$/ml. Therefore, laurinterol was expected as a promising natural antifoulant.t.

• SUVANNABHUMI
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• v.7 no.1
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• pp.157-186
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• 2015

Sittaung-Thanlwin region in Lower Myanmar is an ecological niche for human settlement. Evidences of human activities in the region are seen through various archaeological sites or settlements along the coastal area between the rivers Sittaung and Thanlwin (Salween). In Lower Myanmar, scholar, U Aung Myint, discovered one major site Kyaikkatha and other small scale sites, namely, Sittaung, Kawhtin, Kadaikgyi, Kadaikkalay, Katkadit, Kelatha (little Zothoke), Ayetthama, Winka, Zothoke (big Zothoke), Lagonbyi (Sampannago), Wagaru, Laming and Ye in present day Mon State. In 1980, U Aung Myint undertook an exploration program at Kyaikkatha. After the exploration, an excavation team conducted systematic digging at Kyaikkatha in March 1986. Excavation continued occasionally at Kyaikkatha throughout the years between 1995 and 2000. It is known that Kyaikkatha, the old city, reveals a kind of monumental civilization exposing four religious structures (a stupa and three monasteries). This essay looks into the distribution of features within Kyaikkatha and infers on its social, political, and religious organization. This essay is also about a new discovery of an early urban settlement located at the apex of the Gulf of Muttama (Martaban) where a lost city of Suvannahumi flourished in the ancient days. By means of aerial photographic observations, the site had been noticed recently, which was by followed some excavations. More systematic and detail surveying may be needed to know more about the site and its features for comparison to other similar settlements of through-out mainland South East Asia.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.485-492
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• 2000

Current design practice for the prediction of tunnelling-induced ground movements depends on empirical methods, which are based on many assumptions and simplification of the modeling. Some discrepancies between the predictions and the measurements of ground movements regarding adjacent structures are inevitable. In order to investigate tunnel-induced ground movements affect on the settlement of existing structures as well as existing structures affect tunnel-induced ground movement, 2-D elasto-plastic finite element analysis are performed. The following influencing factors such as load of the structures, the width of structures, its bending and axial stiffness, its position relative to the tunnel are considered in the numerical analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.558-561
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• 2006

In many case, reinforced concrete structures are deteriorated by construction errors, design errors, settlement and movement, and weathering. The diagnose and repair of concrete deterioration is important for effective management of concrete structures. This manual is to provides guideline on evaluating the deterioration of the concrete in a structure and selecting an appropriate repair material and method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.217-226
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• 1993

This study is related to the surface subsidence due to the collapse of a underground void during earthquakes. The amount of the settlement due to the collapse of a underground void will depend on the depth of the void, the initial condition of unit weight of sand, the size and type of foundation, the strength of earthquake, the size of a void, etc. The purpose of the paper is to estimate the amount of the subsidence, analyse the factors affecting the subsidence, and develop a program determining the probability of the damages to structures in terms of absolute and differential settlement and rotational settlement. On the base of the results obtained in this study, when the depth of a void is constant and the width of the void increases, the change of the subsidence factor due to the angle of internal friction and the actual effective factor of the void become smaller than that due to the unit weight of sand deposits. In the same condition, the probabilities of damages due to the absolute and differential settlement increase, and those due to the rotational settlement decrease.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.29-40
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• 2019

Mechanized constructions have been frequently increased in soft ground below sea bed or river bed, for urban tunnel construction, and for underpinning the lower part of major structures in order to construct a safer tunnel considering various risk factors during the tunnel construction. However, it is difficult to estimate the subsidence behavior of the ground surface due to excavation and needs to be easily predicted. Thus, in this study, when a twin tunnel is constructed in the soft ground, it is proposed a simpler equation relating to the settlement behavior and a corrected formula applicable to soft ground and large diameter shield tunnels based on the previously proposed theory by Peck (1969). For this purpose, it was analyzed to long-term measurement values such as the amount of maximum settlement, the subsidence range by ground conditions, and interference volume loss due to the parallel construction, etc. As a result, a equation was suggested to predict the amount of maximum settlement in the soft sediment clay ground where is located at the upper part of the excavation site. It is turned out that the proposed equation is more suitable for measurement data in Korea than Peck (1969)'s.

• Journal of the Korean Geotechnical Society
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• v.37 no.8
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• pp.15-24
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• 2021

Recently, cases for inevitable adjacent construction are increasing due to the limited spaces in urban area. When a new structure is constructed near an existing structure, interference effects induced by the pre-existing structure should be considered. Thus, numbers of studies have been conducted to investigate the effects of adjacent construction, while laboratory scales studies are not well reported. In this study, laboratory scale experiments have been conducted to investigate the bearing capacity and settlement variations with different adjacent construction cases. Results show an optimistic ground bearing capacity increase of the new foundation structure due to the existing foundation structure, while concerns on the increased settlement of the pre-existing structure. Thus, both bearing capacity of the new foundation structure and subsequent settlement of the existing foundation structure have to be considered when assessing the technical applicability of adjacent structure construction on site.