• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.17.2-25
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• 1995

한계상태설계법이 지반공학에 도입되었다. 하중과 지지계력수법 그리고 우로코드로 되어있는 본 설계법에서 신뢰성이론을 토대로 한 전자는 북미지역에서, 반통계론적인 후자는 최근에 통합된 유럽연합에서 오래동안 연구 후 채택하였다. 본 논문은 이러한 설계법을 방법론적으로 검토접근하며 다른 선진국의 연구활동을 알아봤으며, 하중과 지지력계수설계법에서 관입말뚝에 대한 지지력계수를 결정하는 합리적인 방법론을 제시하는데 있다.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.07a
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• pp.65-91
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• 1999

말뚝기초의 지지력예측방법 중 신뢰도가 가장 높은 것은 말뚝정재하 시험방법이므로 말뚝기초의 경제적이고 신뢰성있는 설계를 위하여 하중전이의 측정이 수반된 말뚝재하시험을 실시하여야 할 것이다. 따라서, 말뚝재하시험 방법들에 대하여 고찰하고, 시험결과의 해석사례를 설명하였다. 또한, 신뢰성있는 말뚝재하시험 수행을 위하여 고려해야 할 점들도 설명하였다. 또한, 하중전이측정실험에 대한 기본개념을 고찰하였으며, 이 결과의 활용방안에 대한 설명도 부가하였다.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.5-16
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• 2011

This paper presents the results of a three-dimensional finite element analysis on load supporting mechanism of pile constructed above underground cavity in limestone rock formation. Considering a wide range of cavity conditions, the behavior of pile was studied using the bearing capacity, rock yielding pattern, stress distribution and deformation of pile head and the cavity. The results indicate that the load transfer mechanism of pile, rock yielding pattern and the reduction of bearing capacity of pile significantly vary with the location, size and length of cavity. Based on the results, graphical solutions defining the reduction of the bearing capacity with specific cavity conditions were suggested.

• Geotechnical Engineering
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• v.11 no.4
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• pp.5-12
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• 1995

Although the pile Load test provides various informations to predict the bearing capacity of a pile, it has a considerable difficulty of requiring a large amount of weight to enable the test pile to be loaded sufficiently until the yielding or ultimate load is obtained. Many graphical and mathematical methods have been attempted to estimate the bearing capacity from the result of a vertical load test without loading to failure. In the previous work an analytical method to estimate the failure load using the maxi mum curvature which was based on the Southwell's theory was presented by the author. The failure load, as proposed by Crowther, should be defined as the load at which the predefined that criteria are exceeded. The allowable loads by Davisson's method and DIN 4014 were compared with the loads of piles using the maximum curvature, and this paper proposed the allowable load in which the safety factor of the maximum curvature was 2.5. As a result of study, it was reasonable to conclude that the allowable load determined by the maximum curvature method could estimate the vertical bearing capacity from the pile load test without loading to failure.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.33-45
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• 2004

In the present study, more systematic laboratory model tests under various conditions are carried out to investigate load-sharing characteristics among the granular pile and adjacent soils and bearing capacity characteristics with different pile lengths. Further to evaluate effects of both a loading area and a spacing of pile installation on the bearing capacity and bearing capacity characteristics of each pile in group, model test results are also analyzed for the purpose of an efficient design of granular compaction piles. From the analysis of the model test results, it is found that the ultimate capacity of granular compaction group piles increases with a decrease in the installation distance among granular piles. It is also found that the dominant failure mode of the granular compaction piles is bulging failure. It is further realized that the length of a granular pile could not significantly affect on the ultimate granular pile capacity.

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.1-13
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• 2013

This paper presents the results of a laboratory investigation of the porous pavement substructure effect when reinforced with geocell. In order to analyze load carrying capacity of Geocell, a series of 9 reduced-scale laboratory tests was performed, changing the type, thickness, diameter of Geocell. The results of the analyses indicated that the bearing capacity of the reinforced Geocell increases much more than the non-reinforced Geocell and load carrying capacity was considered to be insignificant according to the type of Geocell. It was also found that the most supportive effects appeared as 30 cm in diameter and 1.8mm in thickness.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.37-46
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• 2001

Pile load tests were carried out to investigate the contribution of the pile cap to the carrying capacity of a pile group and load transfer characteristics of piles in the group. A group of 24 piles$(4 \times6 array)$ of 92.5mm diameter steel pipe were installed to the depth of 3m fron the ground surface, the top of weathered rock. A maximum load of 320ton was applied to the pile cap, $1.5\times2.3m$, in contact with the ground surface. At the maximum load of 320ton, the pile cap has carried 22% of the total load. Average ultimate capacity of pile in the pile group was estimated to be 16.4ton, substantially higher than that of single pile, installed at the corner and tested before pile cap construction. For the same magnitude of settlement, the pile in the center carried less load than the pile at the perimeter due to strain superposition effect. Piles in the group showed almost constant contribution(approx. 60%) of side friction to the total capacity for all of the loading stages, while that of single pile decreased from 82% to 65%.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.61-73
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• 2023

Suction buckets are feasible options for offshore foundations to support subsea structures in deep water, enabling suction-induced installation by pumps. Recently, hybrid suction bucket foundations that combine single or multiple suction buckets with a mat foundation have been considered. The foundations effectively increase the load capacity while reducing construction costs. However, there is still insufficient experimental validation of hybrid suction bucket foundations regarding their bearing capacity. Furthermore, research on the horizontal load capacity under low vertical and moment loads is inadequate. In this study, we investigate the feasibility of using a hybrid suction bucket foundation for subsea installations in clay. We considered two types of hybrid suction bucket foundations: a circular mat with a single suction bucket and a square mat with multiple buckets. Centrifuge tests were performed to understand the hybrid suction bucket foundation characteristics under horizontal loads and their corresponding bearing capacity. Particularly, we verified the effect of the mat foundation and bucket embedment depth on the horizontal bearing mechanism and capacities. Results confirmed that the hybrid suction bucket foundation outperforms the single suction bucket.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.198-208
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• 2011

When a structure which has relatively low load constructs on soft clay, the bearing capacity of the ground will be improved by sand overlying clay. In this condition, verifying the bearing capacity is difficult from the P.B.T etcetera in the in-situ. So, it is needed to estimate precise bearing capacity in the design process. In this study, 2-dimensional chamber tests and FEM analyses are conducted to evaluate behavior of bearing capacity for shallow foundations on a sand overlying clay. Because depth ratio H/B and bearing capacity ratio $q_c/q_s$ are selected as main factors, height of a sand, undrained shear strength of a clay and width of a loading are designated as variables. Results from chamber tests are very similar with those of FEM analyses. And it shows that punching shear mechanism is more suitable than the equation of Okamura et al.(1998). To make continual application of load spread mechanism, the equivalent load spread angle is proposed for H/B and $q_c/q_s$. Also, the linear regression equation of critical depth ratio Hf is suggested for $q_c/q_s$.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.81-89
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• 2008

Shear test procedure for concrete-dowel interaction was proposed along with determination of dowel support reaction factor or shear spring stiffness constant using the spreadsheet example. For this task, three AASHTO-type standard specimens were prepared to simulate behavior of the jointed concrete pavement. A side support system was adopted to minimize twisting of the test specimen which had been observed in a preliminary test. A typical elastic behavior of the dowel-concrete interaction was observed from several test loops of loading, unloading and reloading procedures. However load versus slab displacement represents to be nonlinear. Test results show that the dowel support reaction factor ranges from 550-880 GN/m3, which is 1.4-2.2 times greater than 407GN/m3 proposed by Yoder and Witczak. This is because less torsional distraction was occurred with the help of a side support system adopted in this experiment. The dowel support reaction factor or shear spring stiffness constant obtained from the procedures proposed in this paper may be used as a reference data for the structural analysis of jointed concrete pavement.