• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.87-92
• /
• 2000

The real situation of an underground reinforced concrete(RC) structure with the surrounding soil medium subjected to seismic load is quite difficult to be simulated through an expensive work and, even if it is possible to arrange such an experiment, it will be too expensive. So development of analytical method can be applied usefully to seismic design and seismic retrofit through an analysis of seismic behavior and seismic performance evaluation. A path-dependent constitutive model for soil that can estimate the response of soil layer is indispensible for dealing with kinematic interaction of RC/soil entire system under seismic loads. And interface model which deals with the dynamic interaction of RC/soil entire system is also necessary. In this study, finite element analysis program that can consider path-dependent behavior of RC and soil, and interfacial behavior between RC and soil is developed for rational seismic analysis of RC/soil entire system. Using this program, nonlinear behavior of interface between RC and soil is analyzed, and the effect of interfacial behavior to entire system is investigated.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.6
• /
• pp.727-733
• /
• 2009

This study was performed to investigate the physical characteristics like compressive strength, permeability, porosity and the water quality removal characteristics of permeable concrete pavement filled with microbial-soil sheet to remove SS, organic matter and nutrients in artificial rainfall. As a result, it can show the removal efficiency is SS 90~95%, COD 85~93%, BOD 80~83%, T-N 61~75%, T-P 71~78% on WAPS I(W1) and WAPS II(W2). Therefore, permeable concrete pavement filled with microbial-soil sheet shows higher removal efficiency(SS 10%, organic matter and nutrients 30%) than a conventional porous concrete(W3). By filling microbial-soil sheet to permeable concrete pavement, we confirm that the function and efficiency are improved significantly and that a naturally-friendly facility can be developed and applied to treat non-point sources.

• Computers and Concrete
• /
• v.6 no.1
• /
• pp.79-93
• /
• 2009

In the present paper, a methodology has been presented for the reliability assessment of concrete barriers that lie at a certain depth in the soil, and a missile (a rigid projectile) impacts the top of the soil cover normally, and subsequently after penetrating the soil cover completely it hits the barrier with certain striking velocity. For this purpose, using expressions available in the literature, striking velocity of missile at any depth of soil has been derived and then expressions for the depths of penetration in crater and tunnel region of concrete barrier have been deduced. These depths of penetration have been employed for the derivation of limit state functions. Using the derived limit state functions reliability assessment of underground concrete barrier has then been carried out through First Order Reliability Method (FORM). To study the influence of various random variables on barrier reliability, sensitivity analysis has also been carried out. In addition, a number of parametric studies is conducted to obtain the results of practical interest.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.601-606
• /
• 2002

This study explored physical properties of a hardened cement and a concrete specimen using a high performance cement type solidification consisting of a weathered granite soil and a yellow soil mainly. Also the development of high performance cement type solidification was purposed for an intensity improvement and a long-term durability. As the experimental results, a mortar used by the weathered granite soil shows positive result, however using the yellow soil as a mortar Shows less positive result at the compressive strength. Also the dynamic modulus of elasticity measurement result, the concrete specimens used by the weathered granite and the yellow soil reached above 90%, so it seems to have the durability of freezing and thawing.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.537-540
• /
• 2004

Recently, for industrial development period, concrete structures in domestics have been increased. They were deteriorated by attack of carbonation, freeze-thaw and corrosion etc. In hence they were demolished and reconstructed, resulted in waste concrete particles. In this paper, waste concrete particles (WCP) by product from different crushing and selecting process were used in soil cement-based pavement in the various recycling. For using WCP in soil cement-based pavement, the Qualities, physical and chemical properties, of WCP should be researched. In the first step, the specified compressive strength of mortar for two types of clay sand soil and clay soil respectively was experimented to be 15 Mpa and then optimum mixing ratio of chemical solidification agent were decided in the range of $1.5\~3.0\%$ in the replacement with cement weight content. In the second step, based on the prior experimental results, recycling possibility of WCP in soil cement-based pavement was studied. In the result of experiment the mixing ratio of WCP were 5, 10, 15 and $20\%$ in the replacement with soil weight and the compressive strength of mortar was somewhat decreased according to the increase of the mixing ratio of WCP.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.4
• /
• pp.23-36
• /
• 2008

Soil nailing system can be mentioned to a method of supporting as the shear strength of in-situ soils is increased by passive inclusions. In the general soil nailing system, facing walls are used in two kind of a lattice concrete block or a cast in placed concrete wall. A case of lattice concrete blocks is used in slow slopes greater than 1(V):0.7(H). Also, a case of a cast in placed concrete wall is used in steep slopes less than 1(V):0.5(H). The cast in placed concrete walls are constructed to 30 cm thick together with a shotcrete facing. In this study, the assembling soil nailing method as a new soil nailing system will be proposed. This method is assembly construction using precast concrete panels with 20 cm thick. So, the ability of construction and the quality of facings can be improved more than a conventional soil nailing system. This method can be obtained the effects that a global slope stability increase, as precast concrete panels are immediately put on cutting face after excavating a slope. In this study, confining effects of concrete panels using the assembling soil nailing system were found out by large scaled load tests. In the tests, the load-settlement relationship to an assembling soil nailing system due to the stiff facings as concrete panels appeared to be better than a typical soil nailing system with shotcrete facings.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.73-74
• /
• 2023

In this paper, the characteristics of soil concrete were examined using industrial waste red mud and construction waste circulating aggregate, and if unit cement of 250 kg/m³, it can be used as a soil packaging material by meeting the compressive strength standards for parking lots of SPS-KSCICO-001-2006:2020.

• KIEAE Journal
• /
• v.8 no.1
• /
• pp.81-86
• /
• 2008

Due to the recent environmental problems, lots of studies on the solutions to reduce the environmental pollutions are on the way. In the field of construction, concrete that we are currently consuming approximately 1 ton each year is the most common and cheap building material. We must cut down on this preoccupied use of this material and develop an alternative material as recommended by the late environmental standards. In this regard, this study propose the 'yellow soil' as the main substance that composes the final state, 'yellow soil concrete'. This study also aims to analyze the physical and chemical performances of this concrete mixed with the yellow soil by comparing it with the cement and assesses the possibility of its application to the cement. The results of the experiment shows that, assuming the solidity of the cement concrete to be around $210kg/cm^2$ (20.58MPa), the solidity of the yellow soil combined material may be around 45%~55% in terms of the range of W/B use, 200 to 400 in the per unit fission amount and less than 2% in the addition proportion of admixing agents. But the scope of the optimal concoction amount of the yellow soil concrete should better be limited as following. 40% to 50% in W/B, 300 to 400 in the per unit fission amount and less than 2% in the addition of admixing agents.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.12
• /
• pp.65-72
• /
• 2016

There are numerous factors that affect stress distribution in a buried pipe, such as the shape, size, and stiffness of the pipe, its burial depth, and the stiffness of the surrounding soil. In addition, the pipe can benefit from the soil arching effect to some extent, through which the overburden and surcharge pressure at the crown can be carried by the adjacent soil. As a result, the buried pipe needs to support only a portion of the load that is not transferred to the adjacent soil. This paper presents numerical efforts to investigate the stress distribution in the buried concrete pipe under various environmental conditions. To that end, a nonlinear elasto-plastic model for backfill materials was implemented into finite element software by a user-defined subroutine (user material, or UMAT) to more precisely analyze the soil behavior surrounding a buried concrete pipe subjected to surface loading. In addition, three different backfill materials with a native soil were selected to examine the material-specific stress distribution in pipe. The environmental conditions considering in this study the loading effect and void effects were investigated using finite element method. The simulation results provide information on how the pressures are redistributed, and how the buried concrete pipe behaves under various environmental conditions.

• Geomechanics and Engineering
• /
• v.12 no.6
• /
• pp.899-917
• /
• 2017

Sixty four tests were performed in a steel tank to investigate the axial responses of piles driven into organic soil prepared at two different densities using a drop hammer. Four different pile materials were used: wood, steel, smooth concrete, and rough concrete, with different length to diameter ratios. The results of the load tests showed that the shaft load capacity of rough concrete piles continuously increased with pile settlement. In contrast, the others pile types reached the ultimate shaft resistance at a settlement equal to about 10% of the pile diameter. The ratios of base to shaft capacities of the piles were found to vary with the length to diameter ratio, surface roughness, and the density of the organic soil. The ultimate unit shaft resistance of the rough concrete pile was always greater than that of other piles irrespective of soil condition and pile length. However, the ultimate base resistance of all piles was approximately close to each other.