• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.1
• /
• pp.83-97
• /
• 2018

Tunnels are widely used for special purposes including roads, railways and culvert for power transmission, etc. Its cross-section shape is determined by uses, ground condition, environmental or economic factor. Many papers with respect to behaviours of adjacent ground and existing structure tunnelling-induced have been published by many researchers, but tunnel cross-section have rarely been considered. A collapse of tunnel causes vaster human and property damage than structures on the ground. Thus, it is very important to understand and analyse the relationship between behavoiurs of ground and cross-section type of tunnel. In this study, the behaviour of ground due to tunnel excavation for underground station below the grouped pile supported existing structure was analysed through laboratory model test using a trap-door device. Not only two cross-section types, 2-arch and box, as station for tunnel, but also, offset between tunnel and grouped pile centre (0.1B, 0.25B, 0.4B) are considered as variable of this study. In order to measure underground deformation tunnelling-induced, Close Range Photogrammetry technique was applied with laboratory model test, and results are compared to numerical analysis.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.59-76
• /
• 2020

As a continuous increase in demand for the transportation infrastructure in the metropolitan area, the renovation of existing metropolitan and urban railway lines for the rapid transport system requires the construction of sidetrack that can operate local and express trains simultaneously. However, the construction of sidetrack after stopping the operation of the existing subway line causes a lot of economic losses, therefore it is essential to study the tunnel enlargement scheme during the operation of the existing subway tunnel. Accordingly, in this paper, basic research on the enlargement plan of the existing subway tunnel was carried out for the renovation of the existing subway line. In order to investigate the method for the sidetrack construction, the Government Complex Gwacheon station on the Gwacheon line of subway line 4 was selected as a virtual research station. Subsequently, four construction plans including tunnel cross-sectional plan for each section were reviewed and constructability and economic feasibility were compared. Finally, the stability assessment was conducted for the selected construction plan which was considered to be relatively unstable by 3-D full numerical analysis considering the sidetrack construction process.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.107-120
• /
• 2020

In a performance-based evaluation of structures in use, the current performance is assessed by summing up the weighting of the evaluation indices for each performance. In this study, to suggest a performance-based evaluation technique for NATM tunnels in use, the performance evaluation indices were derived by examining the characteristics and similarities of each index developed from previous study. The weighting of the evaluation indices was derived by calculating the relative importance of each evaluation indices from the AHP analysis. In order to develop a quantitative evaluation model, grading criteria for each performance index was derived through literature review, and performance evaluation tables for road and railway tunnels were presented. In order to verify the significance of the proposed performance evaluation model, the correlation analysis was performed between each evaluation index and the final evaluation result. In the correlation analysis, the survey data measured through precision safety diagnosis in the tunnel in use was applied. It may be said that the proposed evaluation indices, weighting, criteria and evaluation models for tunnels in use can be applied to the performance-based maintenance system of tunnels.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.22 no.1
• /
• pp.1-21
• /
• 2020

The domestic abandoned mines are generating subsidence and it is difficult to predict this subsidence and evaluate the risk. The study of the subsidence risk evaluation using the existing numerical analysis only applies the integrative property to the geological structure and ground condition, and analyzes the goaf peripheral plastic domain. Also, there is a realistic limit that only restricted materials can be apprehended in securing the input information, which leads to the low reliability of the numerical analysis result. In this study, 2-dimensional modeling was performed by applying the field geological structure and ground information targeting abandoned mine where the subsidence occurred. Also, the analysis model was revised by repeating the numerical analysis for the difference between the real subsidence ground information and the analysis result to be minimized by modifying the ground property. This revision was automated by applying the optimization technique and the gradational optimal design method dividing multiple ground properties was developed.

• Women's Health Nursing
• /
• v.5 no.2
• /
• pp.222-229
• /
• 1999

These days, as the society has been in the trends of highly industrialized and the family has been downsized, there is remarkably increasing number of women who follow occupation. These changes have made it more difficult for the family to help post-partum mother, which had been performed in side of house. By the help of social believe that during at least 1 month after childbirth professional nursing program is indispensable for both maternity protection and physical-mental recuperation, now many post-partum care centers for post-partum mother have been in operation. Although these post-partum care center have in use for a long time, no study was performed before this study on the same subject. Data were analyzed using by SAS. The results of study are as follow : 1. The general features of the user of the post-partum care center. The predominant band of user's age is extended from 26 to 30. The users are mainly housewives and they are in higher level of incomes and educations. As for the feature of delivery methods, they performed the normal spontaneous vaginal delivery method by 58.0% and the Caesarean operation method by 42.0%. As for the sexuality for babies, 59.3% of infants are male, and 40.7% are female. The highest delivery order of users is first and admission after 1-3days delivery is highest. 2. The results for the investigation into the actual condition of the post-partum care center are as follow : About the main reason for entrance of the post-partum care center was found to be the needs for the better nursing programs for recuperation after childbirth. This demands are also supported by their husbands. The average length of stay in the post-partum care center is 17.6 days and the besides promised expense ; powdered milk, milk-suckers, disposable dippers, skin cares, body shape cares, entrophics, injections. The post-partum have private rooms for mother and infants. Over the half of average expense is 229 million won. They are paying accessory fees the post-partum care center have similar step organization : the nurses, the skin carers, the cleaners. Mostly both ways of feeding powdered milk and breast feeding are in use, and mother's milk is preserved in the night time to be given to infant by nurse in charge. 3. The results of the investigation on users' nursing demand to the post-partum care center and satisfaction are as follow : The ranking order of nursing demand of mothers who used the is that ; infant care demands, environmental demands, emotional and mental care demands, education and training demands. As much as 70% of the respondents have dissatisfaction in nursing program, The ranking order of service satisfaction of mothers who used appears to be higher following order ; satisfaction in infant care demand, satisfaction in physical nursing demand, satisfaction in emotional and mental nursing demand, satisfaction in education and training demand, satisfaction in environment nursing demand. The results of pearson correlation. between nursing demand and service satisfaction of mothers who used are found to be relative noticeable in the level of 0.05. only infant care. The 61.7% of the women who used the post-partum care center. are responding that they will reuse the same post-partum care center again.

• Women's Health Nursing
• /
• v.5 no.2
• /
• pp.262-277
• /
• 1999

The purpose of this study is to define the effects of the roles played by the Doulas : one group educated on the conventional Lamaze method known to have effects on birth pang during delivery process and the other group educated both on Lamaze and therapeutic touch. On the various factors of delivery, and thereby, provide for some basic data to develop an effective nursing intervention to relieve women of their birth pang. 136 mothers who were hospitalized in a general hospital from June 13, 1998 to May 13, 1998 to May 13, 1999 to deliver their first babies were sampled to be divided into control group, test group I and test group II and thus be subject to interviews and observations. As for the tool of study, melzack's(1975) 'pain scale', McCaffery's(1972) and Mcrachlan's(1974) 'pain expression scales' and Spielberger's (1975) 'anxiety scale' were used. The preparatory educational programs consisted of 5week Lamaze method and therapeutic touch. The research, design was quasi-experimental, non equivalent, posttest only control group design. The collected data were processed using the SPSS/PC statistics software for frequencies, means and one-way Anova as well as Tukey HSD and Scheffe test as post hoc for individual comparison. Moreover, chi-square test was used to test the differences between groups, while Pearson's correlation coefficients were analyzed to determine the correlations between anxiety and variables. The findings are as follows ; 1. The birth pain of the mothers delivering first babies scored in a subjective and objective pain scale; 1) There was a significant difference of subjective birth pain at 8~10cm opening of cervix between control group and two test groups. 2) There was no significant difference of objective birth pain as per opening of cervex among three groups in terms of sweating, facial movement, bodily posture and vocal changes. 2. There was no significant difference of trait anxiety among three groups. however, there was a significant difference of state anxiety during labor process between control group and two test groups. On the other hand, all the three groups showed a significantly lower level of anxiety during labor process than when they were carried to the hospital. 3. There was a significant difference of the time of total and first-stage labor among three groups, while there was a significant but small difference of the time elapsed from 8~10cm cervix open to the full among three groups. 4. Two test groups showed a higher frequency of natural deliveries than the control group. 5. Two test groups were subject to these drugs than the control group. In conclusion, it was found that the test group I and II showed a shorter delivery time than the control group, a higher frequency of natural delivery and a lesser use of anodyne or epidural. In particular, this study is significant to develop a nursing intervention service or a therapeutic touch which the nursing administrators can apply to their hospitals in marketing programs.

• Women's Health Nursing
• /
• v.2 no.2
• /
• pp.230-252
• /
• 1996

Over one million cases of the induced abortion have been conducted annually in Korea. Among those cases, most of all were illegally done, but this has not been addressed in the literature. While Korean Nurse Association Code of Ethics presents the respect for life as one of the basic ideology, it was not dealt enough in nursing education. The purposes of the study were to activate the debate on the issues related to an induced abortion ; to introduce the related ethical theories ; and to seek the solution of the ethical problems, which will eventually result in establishing the morality of nursing practice. The ethical theories of an induced abortion have traditionally addressed two extreme perspectives ; the conservatives who emphasize the sanctity of human life and the right of life that will never ethically allow the killing fetus ; and the liberalists who insist the right to choice for women to control their body. Since these extreme theories has not been helpful to solve the ethical problems, the recent trend is leading to the modified theories both from conservative and liberal perspectives. The examples of the theories are the potentiality of fetus(Singer, 1993), the obligation of women to serve their body to fetus(Held, 1987), the Replacement theory (Callahan, 1987), and the Principle of Caring (Gilligan, 1982). The study conducted the indepth interviews with 17 women who experienced the induced abortion and the 6 cases were selected to be analyzed. The cases were analyzed and interpreted by using an integrated case method which was combined of the New Casuisty(Jonsen & Toulmin, 1988 ; Jonsen, 1991) and the Specified Principlism (Richardson, 1990 ; Degrazia, 1992). The result of analysis revealed three types of ethical problems ; (1) the responsibility of taking care of the baby to be born (2) the fear for the condition of the fetus, and (3) the choice of induced abortion as the method of birth control. The findings also revealed the related ethical principles for various situations ; the principle of caring was used for choosing an induced abortion by the subjects ; the principles of the potentiality of fetus and the obligation of women to serve their body were for the consideration for the life of fetus ; and the principle of replacement was utilized for the right to choice for women. The ethical principles related to an induced abortion introduced in the study provided the way to solve the moral problems by applying to the clinical situations for nurses. The study also revealed the possibility of modifying the current ethical theories from the method of applying the principles to the various situation in the study. The modified theories would be more useful to guide the clinical practice with similar ethical problems.

• Women's Health Nursing
• /
• v.2 no.2
• /
• pp.253-269
• /
• 1996

This descriptive study was done to investigate the proportion of mothers breast feeding and identify factors which influence breast feeding. The subjects were 320 mother who child under five years of age, living in WonJu and their children who numbered 530. Data collection was conducted at various places in the WonJu area using survey questionnaire. The results were as follows : 1. The proportion of children receiving breast feeding was 23.3%, mixed feeding 31.7%, milk feeding 45.1%. The most frequent duration for breast feeding was one month, the mean duration was six months. 2. The major reasons for breast feeding were for the health of the child 52.5%, for emotional attachment with the child 34.2%, and as the expected way of feeding 29.5%. 3. The major reasons for interrupting breast feeding were jobs 26.1%, illness of the child or mother 16.1% abnormality of the breast of nipple 12.7% others 31%. 4. The major reasons for quitting breast feeding were insufficient breast milk 34.5%, job 19.6%, diarrhea in the child 9.9%. 5. The factors influencing breast feeding were educational status and the presence of a job. 6. The husband's attitude to breast feeding was very positive 82.3% and the subjects were supported by their mothers and husbands. But the major information sources about breast feeding were the mass media 30.4% and relatives 22.0%. 7. The breast feeding mother reported experiencing positive and satisfactory feelings, but the milk feeding mother reported experiencing negative and guilt feelings. Also the breast feeding mothers perceived their children as very healthy with a stable emotional status. The results showed the breast feeding ratio in WonJu to be very low and problematic and the subject mothers strongly need information about breast feeding and support while breast feeding. Therefore it is recommended that an education program for community women and other people, like husbands, and grandmothers, be developed along with an education program for university students and other young people to provide them with preparatory information as they begin to think about marriage and families.

• Women's Health Nursing
• /
• v.2 no.2
• /
• pp.182-201
• /
• 1996

The purpose of this study is to examine a married nurse's experience of child rearing through being applied to phenomenological research method. By exchanging their experiences, helping and understanding one another, married nurses can work with delight considering their own present job as their lifelong job. In addition this study can help single nurses overcome the female crises such as marriage, childbirth, and child rearing they will experience in the future. The subjects of this research was 26 married nurses who work for a university hospital in affiliation in Seoul and have children. The period of materials collection was from Feb. 1st to Mar. 3, 1995. The method of materials collection was primarily to write down a questionary with openhearted contents. In collecting it, the respondents were allowed to say at their pleasure through further interview. The materials were analyzed by Giorgi's phenomenological analysis method. The findings of this study are as follows ; 1) The responses of married nurses' experience of child rearing-[pleasure] [family solidarity] [maternal-infant attachment] [understanding] [toilsome]-were induced. That is, at once affirmative experience and hard experience coexisted. 2) The method of married nurses' child rearing-[rearing politely] [raising understanding] [having the sense of family community] [rearing with praying the heart] [careless]-were induced. 3) The support system of married nurses' child rearing-[having help family] [having help from others]-were induced. According to the above findings, the married nursed showed affirmative responses about their experience of child rearing, but at the same time they expressed painful when stayed apart from their children on account of their job or when their children were sick. In the method of child rearing, they tried to grow their children polite because there was much time for them to stay apart from their children. And they tried to give a better explanation in order that their children can have an independence spirit. They tended to compensate through frequent physical touch with their children. As the support system of married nurses' child rearing, they asked their parents or their parents-in-law to take care of their children, hired a nursery governess in their houses, or used a children's home, if they can't afford to. That is, the only one who has a firm sense of her profession, tries to inspire her accomplishment, and is receiving her husband' love and understanding is considered to perform two things simultaneously with harmony, having an recognition of lifelong job. Suggestions 1. The method to solve mental troubles on child rearing should be groped. 2. Their economical burden should be reduced by establishing children's home in their working places, and the increase of maternal-infant interaction should be contrived. 3. The chance of education should be offered in order that married nurses themselves might inspire self-conceit and professionalism on clinical nursing. 4. The familiar mood should be created through planning the programs to be accompanied with children as an annual event in hospital. 5. The part-time nurse system should be suggested to utilize. 6. The system of circulation working should be converted into the system of fixing working according to the characteristic of each department. 7. Programs for special activities such as learning foreign languages and computer should be supported positively.

• Steel and Composite Structures
• /
• v.35 no.6
• /
• pp.799-813
• /
• 2020

Fatigue cracks of rib-to-deck (RD) joints have been frequently observed in the orthotropic steel decks (OSD) using conventional U-ribs (CU). Thickened edge U-rib (TEU) is proposed to enhance the fatigue strength of RD joints, and its effectiveness has been proved through fatigue tests. In-depth full-scale tests are further carried out to investigate both the fatigue strength and fractography of RD joints. Based on the test result, the mean fatigue strength of TEU specimens is 21% and 17% higher than that of CU specimens in terms of nominal and hot spot stress, respectively. Meanwhile, the development of fatigue cracks has been measured using the strain gauges installed along the welded joint. It is found that such the crack remains almost in semi-elliptical shape during the initiation and propagation. For the further application of TEUs, the design curve under the specific survival rate is required for the RD joints using TEUs. Since the fatigue strength of welded joints is highly scattered, the design curves derived by using the limited test data only are not reliable enough to be used as the reference. On this ground, an experiment-numerical hybrid approach is employed. Basing on the fatigue test, a probabilistic assessment model has been established to predict the fatigue strength of RD joints. In the model, the randomness in material properties, initial flaws and local geometries has been taken into consideration. The multiple-site initiation and coalescence of fatigue cracks are also considered to improve the accuracy. Validation of the model has been rigorously conducted using the test data. By extending the validated model, large-scale databases of fatigue life could be generated in a short period. Through the regression analysis on the generated database, design curves of the RD joint have been derived under the 95% survival rate. As the result, FAT 85 and FAT 110 curves with the power index m of 2.89 are recommended in the fatigue evaluation on the RD joint using TEUs in terms of nominal stress and hot spot stress respectively. Meanwhile, FAT 70 and FAT 90 curves with m of 2.92 are suggested in the evaluation on the RD joint using CUs in terms of nominal stress and hot spot stress, respectively.