강우시 불포화 토사사면의 간극수압 변화 특성

심태섭,김선학,신태욱,이광모 朝鮮大學校 建設技術硏究所 2004 建設技術硏究 Vol.24 No.2

This study manufactured model slope in soil. When it is rainfall. It experimented weathered granite soil to be distributed in korea mostly as dividing into two soil sample SP, SM, Moreover, inclination of slope(1:1~1:2) and rainfall strength (50~150mm/hr) divided into five step and it observed seepage behavior of slope according to inclination of slope and rainfall strength. It has manufactured six pore water pressure cells in the lower end of model soil box for measuring pore water pressure to be most important factor of slope failure and analyzed change of pore water pressure according to location of slope when rainfall is continued. Change of saturation depth according to experiment condition is measured through the whole soil box by eyes. In result, in case of being in different rainfall strength in sample inclination. The higher rainfall strength rises, The faster seepage of rain progresses. If angle become gentle from 1:1 to 1:2, The seepage velocity increase, too. If compared theoretical number to calculate by ◁수식 삽입▷ (원문을 참조하세요), that Lumb propose with seepage depth to be measured through indoor model test. As a result, Seepage velocity to measure actually is faster than seepage velocity by formula for Lumb to propose If angle become steep, If shows a tendency for pore water pressure to increase in slope angle from 1:22 to 1:1.5. But in angle from 1:1.5 to 1:1, If angle become steep, It shows a tendency for pore water pressure to decrease gradually as standardizing slope angle 1:1.5, According to rainfall strength increases from 50mm/hr to 150mm/hr. Pore water pressure increases in proportion to rainfall strength.es with the much increase of the pore water pressure.

集中降雨時 無限斜面의 剪斷强度特性에 關한 實驗的 硏究

심태섭,김선학,신태욱,최용준 朝鮮大學校 建設技術硏究所 2004 建設技術硏究 Vol.24 No.2

Granite weathered soil obtained from the cutting slope is divided into two sample materials of SM and SP on the basis of the Unified Soil Classification System (USCS), manufactured the model slope consisting of these, and the pore water pressure and the depth of seepage according to the inclination of the slope and the precipitation strength are measured. From the result of the experiment, the pore water pressure is increased in proportion to the precipitation strength, which is proportionally increased to the inclination of the slope and tends to be decreased when it meets the steep slope of more than 1:1.5. The speed of seepage to the slope in accordance with the precipitation is turned out fast when the inclination of the slope is gentle; according to the result of the Lumbs suggested formula, the actual speed of seepage is faster than the theoretical speed. The shear strength within the slope is decreased as the precipitation strength increases, and since it shows the minimum value at the inclination of the slope in 1:1.5, it can be said that the shear strength declines due to the' increase of the pore water pressure within the slope. Also the slope consisting of SP is faster in the seepage compared to that of SM: and the likelihood of the slope failure is a lot bigger as the shear strength greatly declines with the much increase of the pore water pressure.

다짐도에 따른 화강풍화토의 역학적 특성

심태섭,기완서,주승완,김선학 朝鮮大學校 建設技術硏究所 2002 建設技術硏究 Vol.22 No.1

In this study do we collect the Wethered Granite Soil of Gwang-ju Pung -am district and Youm-ju-dong Gwang-ju world cup stadium construction field and identify physical character according to basic physical test and summerged the sample of 85% degree of compaction in the dry side and wet side in a water tank for ten days on the basis of the sample of 80%, 85%, 90% degree of compaction and Optimum Moisture Ratio in the Optimum Moisture Ratio state in order to exam permeability and compression character of the Weathered Granite Soil according to the compaction state of retaining wall, abutment bankfill banking. We perform falling head permeability test and them standard compaction test and calculate coefficient of permeability and consolidation constant according to the test result. We have a mind to clear permeability and compression character of the Weathered Granite Soil of this study area according to relation curve of the calculated coefficient of permeability, consolidation constant and void ratio, degree of compaction. Therefore compression constant, according to the compaction energy of Optimum Moisture Ratio, is in inverse proportion linearally in the Weathered Granite Soil of WGS-1 and WGS-2 and coefficient of permeability increase directly in a range of void ratio e=0.627∼0.779. e=0.6.57∼0.800.

성토재하에 따른 연약지반의 거동양상

심태섭,김선학,신태욱,성경화 朝鮮大學校 建設技術硏究所 2003 建設技術硏究 Vol.23 No.1

In this study, the behavior analysis of the soft ground is carried out by CRISP 4.02, finite element program using Modified Cam-Clay Model. The used values of the initial parameters were assumed rationally to represent the initial conditions of the ground. In order to analyze the behavior aspect of the soft ground, theory formula, field measure data, and finite element analysis were respectively compared. The result of the present finite element analysis were overestimated in comparison with field measure data. However, field measure data was overestimated in comparison with FEM concerning excess pore water pressure because of the efficiency degree of drain materials and decrease of permeability in the process of consolidation. Both the results of FEM and estimated values by hyperbolic mode1 were overestimated in comparison with field measure, data concerning settlement after three step embankment, but the results of FEM in comparison with estimated values by hyperbolic model were closer field measure data. Therefore, FEM under the careful laboratory tests is recommended as a future research concerning behavior aspect soft ground.

PBT에 의한 얕은기초의 지지력 및 침하량 산정연구

심태섭,기완서,주승완,김선학 朝鮮大學校 建設技術硏究所 2002 建設技術硏究 Vol.22 No.1

A stable and economical bearing force estmate and the upper load condition and foundation ground characteristics are very important in a case of designing shallow foundation. A typicial field test method which get the coefficient of subgrade reaction to estmate bearing capacity of the earthand sand ground foundation and settlement of the soil and rock foundation with most direct method of the field test methods to estimate bearing capacity, is plate bearing test(PBT). So this study refer's to the calculation characteristics of the bearing capacity and settlement according to plate bearing method of the A field and B field which is practiced in the soil of weathered gneiss and soil reclamation ground, and refers to the reasonable settlement calculation method and bearing capacity estmate and safety examination method suitable to the soil of wethered rock and soil reclamation ground according to the plate bearing test result when we examine the structure safety of same design term by awllowable bearing capacity calculation in the point of view of bearing capacity and settlement. Therefore in the methods to determine yield bearing capacity that is applied to allowable bearing capacity calculation when we design shallow foundation and examine safety by plate bearing test, P-S analysis, logP-logS analysis and logP-S analysis are proper methods and it is proper to examine safety by the point of bearing capacity in the soilground to be able t o find the yield point in the Load-Settlement behavior curve.

강우시 불포화 성토사면의 안정해석

심태섭,기완서,김선학,최순범 朝鮮大學校 建設技術硏究所 2005 建設技術硏究 Vol.25 No.1

This study conducted the indoor slope model test which reproduces the rainfall after building up the artificial slope by considering the construction condition of the actual slope in order to understand the characteristics of the change of the quantitative value such as the pore water pressure, dangerous rainfall volume etc, in accordance with the superior seepage of the unsaturated banking slope in the time of rainfall. With this result. the change of the pore water pressure caused by the rainfall seepage, the estimation of time for the slope degradation and of the dangerous rainfall volume, the change of the seepage line, the characteristics of the change in safety rate by using the simplified Janbu's method (1968) have been analyzed and studied. The abstract for this study is as follows: 1. Since the soil within the slope is in the unsaturated state in the early period after the rainfall started, it is started at the pore water pressure of the negative value(-) in the measuring point around the outer layer and of the positive value(+) in the deep area. As the rainfall permeates into the slope, it become saturated, therefore, the pore water pressure also increases which lead to the degradation. After that, it tends to be gradually diminished. The pore water pressure had shown relatively considerable increase right before the degradation, and 50~150 minutes before the slope degradation happens, it had shown sharp increase. 2. The safety rate is sharply decreased when reached the slope layer after being started its activity at the slope line area; the time to the complete degradation of the slope layer by being the 1.0 for the safety rate after the degradation at the slope line area started is displayed short as the rainfall intensity strengthens, and longer as the slope inclination becomes gentler. Likewise, the time to the complete degradation from the slope line to the slope layer is relatively short for the slope built by the 8M than by the one built by the SW.

연약지반에 시공된 보강토 옹벽의 거동해석에 관한 연구

심태섭,최순범,김선학 朝鮮大學校 建設技術硏究所 2007 建設技術硏究 Vol.27 No.1

It was found that the factor of behavior in the retaining wall of reinforced earth on poor subsoil was influenced by load increment, consolidation time and pore-water pressure. Finite element analysis was conducted by using SAGECRISP program for the behavior analysis of poor subsoil and the retaining wall of reinforced earth in this theory. Firstly, the validity of replacement method was examined for the improvement of excessive displacement of the retaining wall of reinforced earth. Secondly, the influence in the ground behavior of the vertical space of reinforced materials on the back of retaining wall was analyzed. Lastly, the width and the depth of appropriate replacement in appling replacement method were suggested. As the result of this study, following conclusion was got. Replacement method take effect on the behavior improvement of the retaining wall of reinforced earth because the case of replacement method(width: 8m, depth: 5m) in the retaining wall of reinforced earth on poor subsoil shows that improvement effect of vertical displacement is 2 ~ 3cm in the upper direction. 7.5 ~ 26.2cm in the lower direction, 11.6 ~ 26.4cm in the vertical displacement on the back of retaing wall and 7.1 ~ 8.6% in shearing strain. The improvement of horizontal displacement was not great because △h_(h)/H maintained similar value despite the increase of replacement width.

일정변형률압밀시험에 의한 연약점토의 압밀특성에 관한 연구

심태섭,김선학,김승철 朝鮮大學校 建設技術硏究所 2001 建設技術硏究 Vol.21 No.1

There is the important labortary test for clays on characteristics of consolidation. This frequently used testing method was developed on the theory of Terzaghi, K.(1936). However, the standard incremental loading consolidation test(IL-consolidation test) has shortcomings, which are long testing time and limited drainage condition, in spite of its importance. So many researchers have been proposing new consolidation tests. For the purpose of decreasing test time, rapid consolidation tests were suggested and advanced testing machine for expanding of drainage conditions. Especially in rapid consolidation tests, due to simplicity and easy equipment of test device, the constant rate of strain (CRS) consolidation test has been the widely used test method and the alternative of IL-consolidation test recentely. This paper is to evaluate consolidational coefficient of soft clay by performing the strain controlled test of Constant Rate of Strain Consolidation(CRS). Compared with the conventional consolidation tests, this technique has an advantage of obtaining the coefficient within a short period of times A series of conventional tests and ORS consolition tests with different rates of strain were performed to investigate the consolidation tests with different rates of strain were performed to investigate the consolidation characteristcs of maraine clay. Preconcolidation pressures were evaluated by applying previously proposed methods for both the conventional tests and CRs tests results in order to check the legitimacy of these methods. The effects of strain rate on effective consolidation stress-strain relationship, porewater pressure, and preconsolidation pressure were also discussed. It was found that the preconsolidation pressure could define from chinnging point of the excess pore pressure. And also the maximum pore pressure was affected by the straine rate. The porewater pressure ratios during CRS tests were in range from 5% to 18%. The strain - vertical effective stress curve could apply for getting coefficient of consolidation better than the void ratio - vertical effective stress curve because of initial void ratio effect.

강우시 침투영향을 고려한 사면안정해석

심태섭,기완서,김선학,최순범 朝鮮大學校 建設技術硏究所 2007 建設技術硏究 Vol.27 No.2

Most of current slope safety analyses consider only the effect of the rise of underground water level. However, because the infiltration of surface water into the ground is believed to have significant effects on slope stability, the present study performed slope safety analysis in case of the rise of underground water level, the infiltration of surface water, and both resulting from rainfall, and examined their effects. For this study, we selected Slope A and B, at which slope failure had happened due to rainfall, and made slope safety analysis in consideration of the fall of wetting front and the rise of underground water level resulting from rainfall. Based on the results of the analysis, we made comparative analysis on the relation between the effect of infiltration on rainfall and the stability of the slopes and proposed a desirable slope safety analysis method. The conclusions of this study are as follows. 1. In slope safety analysis in consideration of the effect of infiltration resulting from rainfall, the variation of safety factor was different depending on whether to consider the fall of wetting front, the rise of underground water level. or both. 2. The decrease of the slope safety factor caused by the fall of wetting front on rainfall was somewhat faster than that caused by the rise of underground water level. This suggests that slope failure caused by rainfall is affected more by the fall of wetting front than by the rise of underground water level. 3. When both the fall of wetting front and the rise of underground water level were considered at the same time, the slope safety factor decreased faster than when either the fall of wetting front or the rise of underground water level was considered. Accordingly, it is considered desirable to consider both the fall of wetting front and the rise of underground water level in slope safety analysis that takes into account the effect of infiltration resulting from rainfall.

한의진단명과 진단요건의 표준화 연구 III : 3차년도 연구결과 보고

최선미,양기상,최승훈,박경모,박종현,심범상,김성우,노석선,이인선,정진홍,이진용,김달래,임형호,김윤범,박성식,송태원,김종우,이승기,최윤정,신순식 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

The diagnostic requirements were suggested and explained regarding the systems of differentiation of symptoms and signs in the third year study of standardization and unification of the terms and conditions used for diagnosis in oriental medicine. The systems were as follows : - analyzing and differentiating of epidemic febrile disease - analyzing and differentiating in accordance with the Sasang constitution medicine based on four-type recognition - differentiation of disease according to pathological changes of Chong and Ren channels - standards for diagnosis of women's disease - standards for diagnosis of children's disease - standards for diagnosis of motor and sensor disturbance (-muscle. born, joint, etc.) - standards for diagnosis of neuropsychiatric disease - standards for diagnosis of five sense organ disease - standards for diagnosis of external disease The indivisual diagnosis pattern was arranged by the diagnostic requirements in the following order : another name, notion of diagnosis pattern, index of differentiation of symptoms and signs, the main point of diagnosis, analysis of diagnosis pattern, discrimination of diagnosis pattern, prognosis, a way of curing a disease, prescription, herbs in common use, disease appearing the diagnosis pattern, documents. The standards for diagnosis of each disease was arranged by the diagnostic requirements in the following order : another name, notion of disease, the main point of diagnosis, analyzing and differentiating of disease, analysis of disease, discrimination of disease, prognosis, a way of curing and prescription of disease, disease in western medicine appearing the disease in oriental medicine, documents.