• Coupled systems mechanics
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• v.3 no.2
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• pp.213-232
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• 2014

Pounding is a major cause of bridge damage during earthquakes. In an extreme situation, it can even contribute to the unseating of bridge girders. Long-span bridges will inevitably experience spatially varying ground motions. Soil-structure interaction (SSI) may play a significant role in the structural response of these structures. The objective of this research is to experimentally investigate the effect of spatially varying ground motions on the response of a three-segment bridge considering SSI and pounding. To incorporate SSI, the model was placed on sand contained in sandboxes. The sandboxes were fabricated using soft rubber in order to minimise the rigid wall effect. The spatially varying ground motion inputs were simulated based on the New Zealand design spectra for soft soil, shallow soil and strong rock conditions, using an empirical coherency loss function. The results show that with pounding, SSI can amplify the pier bending moments and the relative opening displacements.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.91-98
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• 2011

In this thesis, from the results of settlement measurement performed at the site where embankment earthwork was carried out on the ground consisting of highly plastic and silty soft soils interlayered with organic deposits, various methods of predicting the embankment settlement such as Hoshino's method, Asaoka's method, hyperbolic method, ${\sqrt{s}}$ method and Monden's method were used to investigate their applicability and the inverse method of finding the soil parameter related to consolidation was used to predict the consolidation behavior in the future. It was confirmed that reliable prediction of consolidation behavior under various conditions could be done to estimate soil parameter related to consolidation such as the consolidation index and consolidation coefficient by the inverse method of comparing the measured settlement with the predicted value by the settlement prediction methods.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1764-1773
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• 2011

This study is about how to handle very soft grounds consisted of coal and household garbage(organic soil), clay, silt and so on, through examining Seoul-Busan High-Speed railway 6-2nd section. The soft soil might induce long term settlement and lead to structure's differential settlement eventually. So, we performed the boring test for characteristic of railway ground, laboratory test and field survey for mechanical property. And we also collected the engineering data of ground and the data for the establishment arrangement. These data were examined thoroughly considering residual settlement and strength by high-speed railway design standard. As a result of this study, we can say high-speed railway ground must have enough bearing capacity and be settled under allowable residual settlement(10cm). And also it needs to replace soft ground with high quality sand for the fundamental solution. With the application of replacement method on this study, we expect enough condition to construct stable high-speed railway.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.365-372
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• 1998

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.801-813
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• 2017

Passive force acting on the kicker block used to support a raker is different dependent on soil's type. The passive force incorporating a factor of safety is considered for design of the retaining wall. However, an actual passive force developing on the kicker block is overestimated and it may lead to an unsafe design. In this study, the actual passive forces acting on the kicker block in soil ground are evaluated using 3-D Finite Element Program, PLAXIS. Soft and weathered soils are selected as a soil ground. The relation curves between horizontal displacement and actual passive force of the kicker block for each soil ground are obtained through numerical analyses. From the curves, the actual passive forces are determined as a yielding point, which are about 55.5% and 66% of Rankine's passive forces in soft and weathered soils, respectively.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.415-422
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• 1999

The general concept of reinforced roadbed in the high-speed railway is to cope with the soft ground for the bearing capacity and settlement of foundation soil. The cyclic plate load tests were performed to determine the behavior of reinforced ground with multiple layers of geogrid underlying by soft soil. Five series of test were conducted with varying the soil profile conditions including the ground level, type of soil, and the thickness of each soil layer. Based on these plate load tests, laboratory model tests under cyclic loading were conducted to know the effect of geogrid reinforcement in particular for the high-speed rail roadbed. The permanent settlement and the behavior of earth pressure in reinforced roadbed subjected to a combination of static and dynamic loading are presented.

• Journal of Coastal Disaster Prevention
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• v.5 no.4
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• pp.163-172
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• 2018

To propose the design technique and the execution manual of the LWFS(Lightweight Foamed Soil) method using dredged soil, the operation system for the test-bed integrated management, and to establish an amendment for the domestic quantity per unit and specifications, and a strategy for its internationalization. In order to utilize the dredged soil from the coastal area as a construction material, we constructed the embankment with LWFS on soft ground and monitored its behavior. As a result, it can be expected that the use of LWFS as an embankment material on the soft ground can improve the economic efficiency by reducing the depth and period of soil improvement as well as the uses of nearby dredged soil. To verify the utilization of the dredged soil as a material for light-weighted roadbed, soft ground and foundation ground, and surface processing, perform an experimental construction for practical structures and analyze the behavior. It is expected to be able to improve the soft ground with dredged soil and develop technique codes and manuals of the dredged soil reclamation by constructing a test-bed in the same size of the fields, and establish the criteria and manual of effective dredged soil reclamation for practical use. The application technology of the dredged soil reclamation during harbor constructions and dredged soil reclamation constructions can be reflected during the working design stage. By using the materials immediately that occur from the reclamation during harbor and background land developments, the development time will decrease and an increase of economic feasibility will happen. It is expected to be able to apply the improved soil at dredged soil reclamation, harbor and shore protection construction, dredged soil purification projects etc. Future-work for develop the design criteria and guideline for the technology of field application of dredged soil reclamation is that review the proposed test-bed sites, consult with the institutions relevant with the test-bed, establish the space planning of the test-bed, licensing from the institutions relevant with the test-bed, select a test-bed for the dredged soil disposal area.

• The Journal of Engineering Geology
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• v.7 no.3
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• pp.217-227
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• 1997

The purpose of this study is to analyze the correlation of soil properties in coastal soft ground. For the purpose of this study, several coastal soft ground areas were selected. Many large scale construction works are being executed and will increase continuously in these soft ground areas. So, soil property in these areas is very important. The grounds forming coastal areas are affected by seawater movement. So, most of these areas consist of alluvium stratum. Therefore, soil properties of eastern and southern coastal areas are very complex. Many laboratory tests were executed with disturbed and undisturbed soil samples. Undisturbed samples were taken by using thin walled tubes and transported into the laboratory with caution, so as not to disturb the sample. The consistent rate of fine-grained content in these areas is over 90%. Also, these areas contain higher water content and clay content. Therefore, knowing these soil properties, it is possible to safely design fabrics and constructions.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.67-73
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• 2005

In this research, centrifuge model experiments and numerical approach of finite element method to analyze experimental results were performed to investigate the behavior of improved ground with sand compaction piles. One of typical clay minerals, kaolinite powder, were prepared for soft ground in model tests. Jumunjin standard sand was used to sand compaction pile installed in the soft soil. In order to investigate the characteristics of mechanical behavior of sand compaction piles with low replacement ratios, centrifuge model experiments with the replacement ratio of 40%, changing the width of improved area with respect to testing results the width of surcharge loads, were carried out to obtain of bearing capacity, characteristics of load-settlement, vertical stresses acting on the sand pile and the soft soil failure mechanism in improved ground.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.271-278
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• 2002

Soft ground has complex features in mechanic character of ground. Some problems about the settlement and transformation occur if the ground strength is comparatively weak and the depth is large. Therefore, we should consider physical and mechanical characters for safe, economical design and management. As the result of the course, we can compare them with those of field then solve the limitations which were came from the complex character of the soft ground. I have considered the soil's physical character (specific gravity of soil particles, moisture content, grain-size analysis etc) and mechanical character (direct shear test, consolidation, triaxial shear test etc), and then make out a linear interpolation by regression using the two, those and connection of the depth