• Earthquakes and Structures
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• v.8 no.3
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• pp.555-572
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• 2015

This paper presents an experimental study of three two-dimensional (2D/planar) steel reinforced concrete (SRC) T-shaped column-RC beam hybrid joints and six 3D SRC T-shaped column-steel beam hybrid joints under low cyclic reversed loads. Considering different categories of steel configuration types in column cross section and horizontal loading angles for the specimens were selected, and a reliable structural testing system for the spatial loading was employed in the tests. The load-displacement curves, carrying capacity, energy dissipation capacity, ductility and deformation characteristics of the test subassemblies were analyzed. Especially, the seismic performance discrepancies between planar hybrid joints and 3D hybrid joints were intensively compared. The failure modes for planar loading and spatial loading observed in the tests showed that the shear-diagonal compressive failure was the dominating failure mode for all the specimens. In addition, the 3D hybrid joints illustrated plumper hysteretic loops for the columns configured with solid-web steel, but a little more pinched hysteretic loops for the columns configured with T-shaped steel or channel-shaped steel, better energy dissipation capacity & ductility, and larger interlayer deformation capacity than those of the planar hybrid joints. Furthermore, it was revealed that the hysteretic loops for the specimens under $45^{\circ}$ loading angle are generally plumper than those for the specimens under $30^{\circ}$ loading angle. Finally, the effects of steel configuration type and loading angle on the seismic damage for the specimens were analyzed by means of the Park-Ang model.

• Journal of the Korean Society for Railway
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• v.3 no.2
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• pp.84-91
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• 2000

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. With the test results, the bearing capacity ratio, elastic rebound ratio, subgrade modulus and the strain of geogrids under loading were investigated. Based on these plate load tests, laboratory model tests under cyclic loading were conducted to estimate 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 the Korean Geotechnical Society
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• v.27 no.11
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• pp.27-37
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• 2011

A series of centrifuge model tests to investigate the suction pile pullout loading capacity in sand have been performed. The main parameters that affect the pullout loading capacity of a suction pile include the mooring line inclination angle and the padeye position of the suction pile. With respect to the padeye position, the maximum pullout loading capacity is obtained when the padeye position is near 75% of the pile length from the top. The direction of the pile rotation changes when the padeye position reaches somewhere near 50~75% for all mooring line inclination angles. The translation displacement of suction pile to develop the time of maximum pullout loading capacity decreased as the mooring line inclination angle increased. In addition, the vertical displacements of the center of a suction piles for all cases appeared to develop toward the ground surface.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.223-235
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• 2022

Bearing capacity of shallow foundations is often determined for either dry or saturated soils. In some occasions, foundations may be subjected to external loading which is inclined and/or eccentric. In this study, the ultimate bearing capacity of shallow foundations resting on partially saturated coarse-grained cohesionless and fine-grained cohesive soils subjected to a wide range of combined vertical (V) - horizontal (H) - moment (M) loadings is rigorously evaluated using the well-established limit equilibrium method. The unified effective stress approach as well as the suction stress concept is effectively adopted so as to simulate the behaviour of the underlying unsaturated soil medium. In order to obtain the bearing capacity, four equilibrium equations are solved by adopting Coulomb failure mechanism and Bishop effective stress concept and also considering a linear variation of the induced matric suction beneath the foundation. The general failure loci of the shallow foundations resting on unsaturated soils at different hydraulic conditions are presented in V - H - M spaces. The results indicate that the matric suction has a marked influence on the bearing capacity of shallow foundations. In addition, the effect of induced suction on the ultimate bearing capacity of obliquely-loaded foundations is more pronounced than that of the eccentrically-loaded footings.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1526-1531
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• 2008

The objective of this study is to evaluate the loading capacity of lattice girder according to loading position. 3-point flexible strength tests were performed on three types of lattice girder, such as LG-$50{\times}20{\times}30$, LG-$70{\times}20{\times}30$, and LG-$95{\times}22{\times}32$, mainly used in Korea. Two types of loading position for each flexible strength test were used to analyze the behavior of load-deformation. In 3-point flexible strength test, the difference of the average of maximum flexible strength according to loading position had the range from 10% to 33%.

• International journal of steel structures
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• v.18 no.5
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• pp.1801-1817
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• 2018

This paper presents the numerical parametric analysis on the loading capacity of Channel purlins with screw-fastened sheeting, in which the effects of anti-sag bar and corrugated steel sheet on the ultimate capacity are studied. Results show that the setup of anti-sag bars can reduce the deformations and improve the ultimate capacity of C purlins. The traditional method of setting the anti-sag bars in the middle of the web is favorable. The changing of sheeting type, sheeting thickness and rib spacing has significant effects on the ultimate capacity of C purlins without anti-sag bars, compared with those with anti-sag bars. The proposed design formulas are relatively consistent with the calculations of EN 1993-1-3:2006, which is different from those of GB 50018-2002.

• Earthquakes and Structures
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• v.22 no.6
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• pp.597-608
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• 2022

One of the most important parameters affecting nonlinearsoil-structure interaction, especially rocking foundation, is the vertical factor of safety (F.S_v). In this research, the effect of F.S_v on the behavior of rocking foundations was experimentally investigated. A set of slow, cyclic, horizontal loading tests was conducted on elastic SDOF structures with different shallow foundations. Vertical bearing capacity tests also were conducted to determine the F.S_v more precisely. Furthermore, 10% silt was mixed with the dry sand at a 5% moisture content to reach the minimum apparent cohesion. The results of the vertical bearing capacity tests showed that the bearing capacity coefficients (N_c and N_γ) were influenced by the scaling effect. The results of horizontal cyclic loading tests showed that the trend of increase in capacity was substantially related to the source of nonlinearity and it varied by changing F.S_v. Stiffness degradation was found to occur in the final cycles of loading. The results indicated that the moment capacity and damping ratio of the system in models with lower F.S_v values depended on soil specifications such cohesiveness or non-cohesiveness and were not just a function of F.S_v.

• Geomechanics and Engineering
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• v.6 no.3
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• pp.249-262
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• 2014

Tire chips and tire chips-soil mixtures can be used as alternative fill material in many civil engineering applications. In this study, the potential benefits of using tire chips as lightweight material to improve the bearing capacity and the settlement behavior of sand slope was investigated experimentally. For this aim, a series of direct shear and model loading tests were conducted. In direct shear tests, the effect of contents of the tire chips on the shear strength parameters of sand was investigated. Different mixing ratios of 0, 5, 10, 15 and 20% by volume were used and the optimum mixing ratio was obtained. Then, laboratory model tests were performed on a model strip footing on sand slope reinforced with randomly distributed tire chips. The loading tests were carried out on sand slope with relative density of 65% and the slope angle of $30^{\circ}C$. In the loading tests the percentage of tire chips to sand was taken as same as in direct shear tests. The results indicated that at the same loading level the settlement of strip footing on sand-tire chips mixture was about 30% less than in the case of pure sand. Addition of tire chips to sand increases BCR (bearing capacity ratio) from 1.17 to 1.88 with respect to tire chips content. The maximum BCR is attained at tire chips content of 10%.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.148-154
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• 2001

The uplift capacity of a pile for improving the wind resistance of the 1-2 W type plastic film pipe on greenhouses was tested using the plane and corrugated piles with various shapes and diameters. First, the resistant uplift capacity was measured by using the uplift loading on plane piles. As the uplift loading on plane piles increased, the resistant uplift capacity also increased until the loading was reached to ultimate uplift capacity. After ultimate uplift capacity was appeared the uplift displacement, the uplift capacity was decreased gradually. Secondly, the resistant uplift capacity was measured by using the uplift loading on corrugated piles. After the uplift capacity was reached the uplift displacement, the uplift capacity was continually increased or decreased. In general, the ultimate uplift capacity was independent of pile shapes, pile diameter length, and embedded pipe depth. However, the ultimate uplift capacity of a corrugated pile was twice more than that of a plane pile without regard to its diameter and embedded depth. The ultimate uplift capacity per unit pile area was increasing in deeper embedded depth. However, the longer a pile diameter was, the less ultimate uplift capacity. The uplift capacity of a plane pile, used in conjunction with the design wind velocity (26.9m.s$^{-1}$ ) of the project area, was unsatisfiable without regard to diameters and embedded depths of piles, while most of corrugated piles were well appeared uplift capacity under various experimental conditions.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.2
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• pp.31-37
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• 1997

Structural details of the three-bay-straw-roof house which was the most common form of residence as a commoner's house during ancient period are suggested. Wooden frames are used in the house. The typical form of joint used is Sagaemachum. The static lateral loading capacity of the frames is evaluated through the test on full scale models. The effects of joint type at the column head and wooden lattice on the lateral loading capacity and the failure modes of frames are analyzed. The ultimate lateral loading capacity and displacement of the ordinary frame at failure are 1.090 N and 400 mm(1/6rad), respectively. These values for the frame with high column are 4,160 N and 250 mm(1/9.6rad), respectively. The behavior of joint at column head controls the overall lateral loading capacity of the frame and shows very large nonlinearity. The general failure modes of joint for an ordinary frame and a frame with high column are shear and bending failure at the branches of Sagaemachum, respectively.