• Journal of the Korean Geotechnical Society
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• v.33 no.7
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• pp.5-16
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• 2017

Soil nailing is the most general method to reinforce the slope by taking pullout and shear resistance force of the nail for stabilizing the slope. Domestic soil nailing design method considers only pullout resistance and does not consider the shear resistance sufficiently. In case of nail, the effect of tensile stress is dominant, but it is desirable to design by considering shear stress as well as tensile stress in case of slope where circle failures occur. Recently, studies on the shear resistance effect of nails have been carried out in the geotechnical field. However, many researches on the shear reinforcement effect of soil nailing have not been conducted until now. Most of the studies are about increasing pullout resistance by improving material, shape and construction method of nail. Therefore, it is necessary to the study on shear resistance of soil nailing and development of new methods to increase the shear force. In this study, large shear test and limit equilibrium analysis have been performed for a new soil nailing method to increase the shear resistance by forming protrusions through pressurized grouting after installing a packer on the outside of deformed bar. The study results showed that shear resistance of protrusion type soil nailing increased compared to soil nailing and it is more effective when applied to the ground with large strength parameters.

• Geotechnical Engineering
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• v.12 no.3
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• pp.63-72
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• 1996

Plate anchors are often used for various types of offshore construction and maintenance works. When the plates are embedded in soft clay and subjected to sustanined allowable loads, creep may develop. This paper presents some results from laboratory model test designed to study the creep effect that develops with time for a shallow circular anchor subjected to sustained net loads that are less than the net ultimate uplift capacity. Based on the model test results, relationships among the net load, the rate of strain, and time are developed.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.167-174
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• 1999

A Land slide in Granitic Gneiss weathered soil was stabilized successfully with soil nailing using 929mm steel bar. To understand the behavior of load transfer between soil and nail, in-situ pdl-out tests were carried out. The strains of steel bars were measured using strain gauges during pull-out tests. Forces-strain data from laboratory tension tests on steel bar and grouted steel bar were examined to compare with those of the pull-out tests. Comparisons were made between the pull-out test results and laboratory test result to understand load transfer mechanism.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.137-144
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• 1999

Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study removable soil nails are developed and field pull-out tests are carried out 16 times in order to analysis pull-out characteristics of the removable soil nail. For the spacing and the installed position of fixed socket, the length of the soil nail, and W/C ratio of cement grout in the removable soil nail, pull-out characteristics of pull-out tests are analyzed. From the pull-out characteristics of removable soil nails, it is found that the spacing of fixed socket and W/C ratio of cement grout are important design parameters.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.639-642
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• 1999

Pullout test known as Lok test among the test methods to evaluate concrete strength strength is a test method which is used to decide the form removal time by assessing the early strength of concrete in a new construction, or to control the quality of newly placed concrete. This method has inconvenience to place inserts on the form work in advance, however, the placing work is quite simple and it has advantage that the strength can be measured at field as long as the inserts are placed. In this study, the first step is to investigate the properties of test method itself, by performing the laboratory test which covers deviation of the method and factors affecting the results, etc. The second step is to correlate the result with cylinder strength and other NDT methods such as rebound hammer, ultrasonic method, etc. And that, the results are compared with foreign results to find the differences between the two. In this research, new factors such as moisture content, area of aggregate failure cross section and area of aggregate separation cross section, etc as well as wate-cement ratio and age are investigated.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.819-824
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• 2005

Anchor system is widely used in construction works to support retaining structures. The compression anchor is characterized by excellent mechanism of pullout resistance, as well as less probability of progressive failure than a tension anchor. This paper presents the mechanical characteristics of a newly developed compression anchor(JR-2000). Field tests were performed to investigate characteristics of the pullout resistance of compression anchor.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.342-347
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• 2004

Excavation nearby the existing structures is being performed vigorously to get the greatest use of land along with fast economic growth in the downtown area. The application of soil nailing system gradually increases because of an advantage of soil nailing system adjacently constructed in the existing structures. In this study, friction resistance by pull-out is considered as main resistance except resistance formed by flexural rigidity of nail observing that resistance of flexural rigidity is about $0{\sim}15\;%$ of whole safety factor according to degree of flexural rigidity in general soil nail wall and application of geosynthetic fiber soil nailing system is evaluated through laboratory tensile strength test and field pull-out test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1433-1438
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• 1994

Laboratory model test results for uplift capacity of a circular plate anchors embedded in saturated clayey soils have been presented. Clayey soils used in this study are kaolinite and montmorillonite. Suction effects on the ultimate uplift capacity of plate anchors with respect to various embedment depths of anchor have been considered.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.211-215
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• 1996

This paper presents comparisons of pullout load of concrete with compressive strength of cylinders and cores, pulse velocity, and rebound number. A pullout test, which is a relatively new nondestructive technique, measures with a special tension ram the force required to pullout a specially shaped steel rod whose enlarged end has been cast into a concrete block. In this study 3 concrete mixes(normal strength, high-strength & super-high-strength) were made. From each mix, one 100$\times$70$\times$20 concrete block, 24 cylinders$(\phi10mm)$were casted. Each tests were performed on the concrete blocks at 3, 7, 28, and 91days. The test data shows that the pullout test is superior to the rebond hammer and the pulse velocity measurements on the evaluation of concrete strength. The pullout test is satisfactory for estimating the strength of in situ concrete at both early and late age, and its results can be reproduced with an acceptable degree of accuracy.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.119-126
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• 2004

Behaviour of soil nailed walls in Korea has been analysed based on a number of field measurements. The investigation has included interface shear strength development at the nail-soil interface from pull-out tests, lateral ground displacements, tensile force distributions along soil nails and mobilised interface shear stress distributions. Insights into the soil nailed wall behaviour based on the shear transfer mechanism at the soil-nail interface and partial mobilisations of the interface shear strength, governed by relative shear displacement, are reported and discussed. It is expected that results from the current research can provide relevant parameters required for preliminary design of soil nailed walls in Korea.