• Journal of the Korean GEO-environmental Society
• /
• v.4 no.4
• /
• pp.61-71
• /
• 2003

On the soft soil consisted of silty clay, the compulsion replacement method is useful for revetment and its safety is very much affected by compulsion replacement depth. Usual method calculating the compulsion replacement depth on silty clay is considered the bearing capacity of soft soil with undrained shear strength increase from ground surface and weight of revetment. But according to soil deposit, there are some cases of soft soil with inter sand layer or clayed silt, which affect the compulsion replacement depth. In this paper, the compulsion replacement depth on soft soil with inter sand layer is analyzed by layered weighted average bearing capacity considering influence effect of Perloff et al.(1967) and compared with numerical method(FLAC). In the result, the calculated depth from numerical method is nearest to layered weighted average bearing capacity in case that contact width under revetment is $0.2B_o$(soft soil with inter sand layer), $0.5B_o$(only soft soil) and the effect of contact width under revetment is less than undrained shear strength, thickness and location of inter sand layer. Also the compulsion replacement depth is as much as the inter sand thickness($d_2/B_o$) is thinner, the inter sand layer location($d_1/B_o$) is farther, and undrained shear strength is less.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.5C
• /
• pp.283-292
• /
• 2008

In this research, finite difference (FD) scheme for the interface of the layer between different soil characteristics was suggested. Based on the suggested scheme, FD analysis program for the consolidation analysis of the multi-layered and smeared soil was developed. And the applicability of the program was investigated by the FD analysis conducted for the various soil conditions. Analysis results showed that the permeability near the drainage boundary had a dominant effect on the consolidation rate. And the consolidation rate of the soil with the constant permeability in smeared area was retarded more than the soil with the linear variation of permeability in smeared area. Simple assumption of the constant variation of permeability in smeared area could be used when the decreasing rate of permeability in smeared area was relatively low. But exact assumption of the permeability variation in smeared area should be considered when the decreasing rate of permeability in smeared area was relatively high. Finally, based on the analysis result on Busan area, the analysis considering multi-layered soil should be needed to exactly evaluate time for the completion of consolidation.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1994.09a
• /
• pp.129-138
• /
• 1994

It is well recognized that accurate analysis of lateral earth pressure is very signficant factor which determines the design amount of braced cut walls and braced systems. Many researchers, Peck, Terzaghi-Peck and so on, make a study about lateral earth pressure to act on the flexible walls. But these studies trouble accurate to multy layered systems like inland areas in Korea. This study is compared with the field messurement data to estimate the earth pressure distributions in multy layered areas and the empirical earth pressure distributions. The conclusions are as follows : At final excavation depth, the lateral earth pressure which messured by field instrument is smaller than the empirical earth pressure. (About 1.85~5.32 times). In the case of considering the soft rock layer to the final excavation depth, the messured earth pressure is safe to be compared with empirical earth pressure. The messured earth pressure distributions are like that the upper soil layer is small the middle soil layer is large, the rock mass layer is very small.

• Geotechnical Engineering
• /
• v.14 no.3
• /
• pp.63-72
• /
• 1998

Laboratory model test results for ultimate uplift capacity of horizontal circular anchors embedded in soft clay overlain by dense sand are presented. The effect of the critical embedment ratio on the thickness of the clay layer was evalyated. An approximate preocedure for estimating the net ultimate capacity is presented.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.10a
• /
• pp.417-424
• /
• 2005

Observed field behaviors are frequently different from the behaviors predicted in the design state due to several uncertainties involved in soil properties, numerical modelling, and error of measuring system even though a sophisticated numerical analysis technique is applied to solve the consolidation behavior of drainage-installed soft deposits. In this study, genetic algorithms are applied to back-analyze the soil properties using the observed behavior of soft clay deposit composed of multi layers that shows complex consolidation characteristics. Utilizing the program, one might be able to appropriately predict the subsequent consolidation behavior from the measured data in an early stage of consolidation of multi layered soft deposits. Example analyses for drainage-installed multi-layered soft deposits are performed to examine the applicability of proposed back-analysis method.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.10a
• /
• pp.304-311
• /
• 2004

In this paper, three dimensional dynamic infinite elements are developed for the soil-structure interaction analysis in multi-layered halfspace. For the efficient discretization of 3-D for field regions, five types of dynamic infinite elements are developed. They are the horizontal, vertical, upper horizontal conner, lower vertical conner and conner of conner infinite elements. The shape functions of the infinite elements are based on the approximate expressions of the analytical solutions of the propagating waves in the infinite region. Numerical example analyses are presented for demonstrating the effectiveness of the proposed infinite elements.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.10a
• /
• pp.79-86
• /
• 2003

In this paper, three dimensional dynamic infinite elements are developed for the soil-structure interaction analysis in multi-layered halfspace. For the efficient discretization of 3-D for field regions, five types of dynamic infinite elements are developed, they are the horizontal, vertical, upper horizontal conner, lower vertical conner and conner of conner infinite elements. The shape functions of the infinite elements are based on the approximate expressions of the analytical solutions of the propagation wave in the infinite region. Numerical example analyses are presented for demonstrating the effectiveness of the proposed infinite elements.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.23 no.3
• /
• pp.191-199
• /
• 2019

To calculate proper seismic design load and seismic design category, the exact site class for construction site is required. At present, the average shear-wave velocity for multi-layer soil deposits is calculated by the sum of shear-wave velocities without considering of vertical relationship of the strata. In this study, the transfer function for the multi-layered soil deposits was reviewed on the basis of the wave propagation theory. Also, the transfer function was accurately verified by the finite element model and the eigenvalue analysis. Three methods for site period estimation were evaluated. The sum of shear-wave velocities underestimated the average shear-wave velocities of 526 strata with large deviations. The equation of Mexican code overestimated the average shear-wave velocities. The equation of Japanese code well estimated the average shear-wave velocities with small deviation.

• Journal of the Korean Professional Engineers Association
• /
• v.24 no.1
• /
• pp.33-56
• /
• 1991

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2006.06a
• /
• pp.158-159
• /
• 2006