• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.113-132
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• 1999

Recently in Korea, application of the soil nailing is gradually extended to the sites of excavations and slopes having various ground conditions and field characteristics. Design of the soil nailing is generally carried out in two steps, The First step is to examine the minimum safety factor against a sliding of the reinforced nailed-soil mass based on the limit equilibrium approach, and the second step is to check the maximum displacement expected to occur at facing using the numerical analysis technique. However, design parameters related to the soil nailing system are so various that a reliable design method considering interrelationships between these design parameters is continuously necessary. Additionally, taking into account the anisotropic characteristics of in-situ grounds, disturbances in collecting the soil samples and errors in measurements, a systematic analysis of the field measurement data as well as a rational technique of the optimum design is required to improve with respect to economical efficiency. As a part of these purposes, in the present study, a procedure for the optimum design of a soil nailing excavation wall system is proposed. Focusing on a minimization of the expenses in construction, the optimum design procedure is formulated based on the genetic algorithm. Neural network theory is further adopted in predicting the maximum horizontal displacement at a shotcrete facing. Using the proposed procedure, various effects of relevant design parameters are also analyzed. Finally, an optimized design section is compared with the existing design section at the excavation site being constructed, in order to verify a validity of the proposed procedure.

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.31-49
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• 2002

The purpose of this study was to investigate discomforts and sexual life and to identify the relation between the discomforts and sexual life with low back pain. The data were collected from March 2 through July 31, 2001. Four hundred forty-two questionnaires were returned (response rate=88.0%). Analysis of the data was done with SPSS PC+ and use descriptive statistics, $x^2$-test, t-test, ANOVA. regression. The statistics shows that over than 80% of the adults experienced lumbago at least one time in their life, and Back pain is known as one of the most common complaints made by the patients of all ages in the general hospital or local medical clinics throughout. However, in certain case it leads to a chronic condition which can cause a great deal of problems in management and in financial burden to individuals and society. The result of this study was summarized as follows: 1) It appeared that regarding the distribution of gender, male was the higher(63.6%) then that of female, the portion of forties was 28.5%. Sitting for long time was 23.1% in men and 21.7% in women. Unknown reason including sexual behaviour was 12.9% in men and 15.5% in women. Patients treated medicine and physical therapy were 36.4%. In level of educational background, the rate of high school was 31.0%, technical college was 28.5%. The highest proportion by occupation was 18.3% of office workers, occupation posture was 41.9% of sitting. 2) Men(26.0%) and most of women(34.8%) were not satisfied in the explanation satisfaction rate of sex life concerned disease. 23.8% in men and 23.6% in women considered flexibility of waist good. Man(33.3%) and most of woman(35.0%) considered that Health education is necessary. 32.7% in men and 27.3% in women did't mind educator is whoever. Preventing of lower back pain(LBP) and proper Health education of sex life are demanded in daily life. 3) 58.0% of man and 64.0% of woman mostly had a posture which is man over woman. 28.5% in men and 27.8% in women considered that proper information finding of LBP and sex life was very few and few. 37.7% in men and 42.7% in women have acquired information about sex life flung their friends. 4) The number of sex life was decreased from 2.96 0.98 to 2.61 1.63 and also the time of sex life was decreased from 3.65 1.89 to 226 1.64. The satisfaction rate of sex life changed from 3.60 0.86 to 2.77 1.10. In the number of sex life, The non correct group was 2.62 1.91 and the correct group was higher in 2.68 1.65. In the time of sex life, The non correct group was 2.02 1.47 and the correct group was higher in 229 1.65. The satisfaction rate of sex life was 2.76 0.86 in non correct group and 2.88 1.10 in correct group. So there was a difference. 5) In the satisfaction rate of sex life, Men who have a lower back pain were higher than women and no attack group was higher than attack group. As they had many sex life, the satisfaction rate was higher significantly in statistics. As the time of sex life was short, the satisfaction rate was lower significantly in statistics. As the age was low, the demand rate of Health education was high and as means of patient who had a lower back pain was high, the demand rate of Health education was high. As the patient who had a lower back pain had a long married life, the demand rate of Health education was high and as education level was high, the demand rate of Health education was high. It is necessary to provide patients with conservative treatment, educational teaching, and training to prevent further injuries in the future. In general, it is important to educate the public how to prevent back injuries and how to treat themselves in an onset period to prevent further injuries sliding into a chronic state. Sexuality is an integral part of normal and healthy relationships, but patients are unable to enjoy sex because they are riot able to get into a comfortable position due to back pain. Many conditions of the spine can make certain positions uncomfortable. Health educator should make the education program of the discomforts and the sexual pattern for low back pain in workplace and/or hospital. Further study Is needed on how to integrate the educational program on sexuality into the total rehabilitation program.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.05a
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• pp.35-81
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• 1998

Distinct Element Method(DEM) has a great advantage to model the discontinuous behaviour of jointed rock masses such as rotation, sliding, and separation of rock blocks. Geometrical data of joints by a field monitoring is not enough to model the jointed rock mass though the results of DE analysis for the jointed rock mass is most sensitive to the distributional properties of joints. Also, it is important to use a properly joint law in evaluating the stability of a jointed rock mass because the joint is considered as the contact between blocks in DEM. In this study, a stochastic modelling technique is developed and the dilatant rock joint is numerically modelled in order to consider th geometrical and mechanical properties of joints in DE analysis. The stochastic modelling technique provides a assemblage of rock blocks by reproducing the joint distribution from insufficient joint data. Numerical Modelling of joint dilatancy in a edge-edge contact of DEM enable to consider not only mechanical properties but also various boundary conditions of joint. Preprocess Procedure for a stochastic DE model is composed of a statistical process of raw data of joints, a joint generation, and a block boundary generation. This stochastic DE model is used to analyze the effect of deviations of geometrical joint parameters on .the behaviour of jointed rock masses. This modelling method may be one tool for the consistency of DE analysis because it keeps the objectivity of the numerical model. In the joint constitutive law with a dilatancy, the normal and shear behaviour of a joint are fully coupled due to dilatation. It is easy to quantify the input Parameters used in the joint law from laboratory tests. The boundary effect on the behaviour of a joint is verified from shear tests under CNL and CNS using the numerical model of a single joint. The numerical model developed is applied to jointed rock masses to evaluate the effect of joint dilation on tunnel stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.331-337
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• 2016

Several foundation soil conditions below a homogeneous sand slope were assumed and slope stability analyses were conducted to determine the soil condition, in which a stabilizing pile can be used to increase the factor of safety against sliding. The assumed heights of the sand slope were 5m and 10m. For a 5m slope height, a stabilizing pile can be used in the foundation soil with a $15^{\circ}$ internal friction angle and a cohesion of 10kPa. For a 10m slope height, a stabilizing pile can be used in the foundation soil with a $20^{\circ}$ internal friction angle and a cohesion of 10kPa and a stabilizing pile can be used in the foundation soil with a $0^{\circ}$ internal friction angle and 40kPa, 45kPa and 50kPa of cohesion. According to the analysis results of stabilizing pile-reinforced foundation soil, the length of the stabilizing pile and magnitude of the maximum bending moment were strongly affected by the internal friction angle of the foundation soil. The lengths of stabilizing pile, for an internal friction angle of $0^{\circ}$ were 4.6, 8.0 times greater than those with an internal friction angle of $5^{\circ}$. The magnitude of the maximum bending moment of the stabilizing pile for an internal friction angle of $0^{\circ}$ was 24.6 times greater than that for an internal friction angle of $5^{\circ}$. Practically, a stabilizing pile cannot be used for foundation soil with an internal friction angle of $0^{\circ}$. Considering the results derived from this study, the effects of a stabilizing pile can be maximized for soft foundation soil that is embanked with a slow construction speed.