In the convergence–confinement method, the longitudinal deformation profile (LDP) serves as a graphical representation of the actual tunnel convergence (both ahead of and behind the face); therefore, it is considered important for determining the distance of support installation from the face or the timing after excavation in this method. The LDP is a function of the rock mass quality, excavation size, and state of in situ stresses; thus, obtaining the LDP according to the rock mass conditions is essential for analyzing the complete behavior of convergence during tunnel excavation. The famous LDP shows that the best fit for the measured values of tunnel internal displacement reported simply expresses the ratio of the preceding displacement as approximately 0.3. This can lead to an error when predicting the ratio of the preceding displacement while neglecting the rock conditions; consequently, a complete tunnel behavior analysis cannot be realized. To avoid such error, the finite difference method software FLAC 3D is used to develop an expanded longitudinal deformation profile (ELDP) according to the rock mass conditions. The ELDP is represented by graphs featuring different shapes according to the rock mass rating (RMR), and the empirical formula of the LDP best fitted for the tunnel convergence measurement values is expanded. This expanded LDP formula is proposed in a generalized form, including the parameters α and β from the empirical equation. These parameters α and β are expressed as functions of the RMR and initial stress. Statistical analysis results of the 3D numerical analysis of 35 cases were analyzed in the ranges of α = 0.898–2.416 and β = 1.361–2.851; this result is based on the empirical formula of Hoek (1999) (α = 1.1, β = 1.7), which was expanded in the current study according to the rock quality and initial stress conditions.
Department of Nursing Science, International University of Korea²Department of Physical Therapy, International University of Korea(Received March 10, 2013: Revised April 2, 2013: Accepted March 2, 2013)AbstractPurpose. The purpose of this study was to contribute to the development of the sexual education program by examining status of Sexual Violence Consciousness and Cognition of Sexual Violence of University studentsMethods. The subjects were 240 University students located in J-city. Data were collected during the period from Nov. 12, 2012 to Nov. 13, 2012. For the data analysis, SPSS 12.0 K program was utilized to get frequency number, percentage, average, standard deviation and t-test. Results. The results present different degrees of man and women's cause of sexual violence cognition and consciousness were as following ; The several scores of women higher more than man parts were ‘Think of the woman as a sexual target(t=3.86, p<0.001)’,‘Men's sexual urges(t=3.98, p<0.001)’, ‘The low status of women in society (t=3.85, p<0.001)’, ‘Male-dominated society and culture(t=5.62, p<0.001)’, ‘Acceptance of men aggression and activism(t=5.19, p<0.001)’,‘Weak punishment (t=7.25, p<0.001)’and Man higher more than women parts were ‘overexposure of women(t=3.88, p<0.001)’.Conclusion. Results suggest that sexual education program should strategies to increase a positive Consciousness and Cognition of Sexual Violence in their education programs in order to improve Consciousness and Cognition of Sexual Violence in University students.
Rock fragments obtained by excavation can provide information for evaluating the excavation efficiency, for which the coarseness index (CI) and particle size parameters (d50, dMPS, and d′) are used. However, CI depends on the number and size of the sieves used, and the particle size parameters require mathematical calculations. In this study, the maximum diameter (dmax) of rock fragments was used as an indicator of the excavation efficiency. Linear cutting tests were performed and the rock fragments were sieved to obtain the CI and dmax. The relationship between dmax and CI was similar to that between other particle parameters and CI. dmax and CI increased with increasing penetration depth and spacing, but dmax followed a linear relationship, and CI demonstrated a power relationship. Both dmax and CI reached their maximum values at a specific ratio of spacing to penetration depth (s/p ratio) and were not affected by subsequent increases in s/p. The cutting force and volume had positive relationships with dmax and CI, linear with dmax and exponential with CI, whereas the specific energy (SE) had an inverse relationship, showing exponential and linear relationships with dmax and CI, respectively. When dmax was larger than a certain value, SE converged to a constant value. This study confirmed that dmax has an advantage over CI in determining excavation efficiency.
During underground construction, the behavior of the ground is influenced by characteristics of the rock mass with situ stresses and ground water, cross section of the excavation area, excavation method, and the rate of excavation. These fundamental features are considered to ensure the support and stability of underground excavations and achieve long-term successful operation. However, the ground composition of the Himalayas hinders tunnel excavation, especially in case of mechanized tunneling; this causes time and cost overruns. This study has reviewed the recently completed Neelum–Jhelum Hydroelectric Project; the project complexities, geological environments involving significant overburden and tectonic stresses, and effects of the excavation method on tunnel stability were analyzed. The major challenges that were encountered during construction are discussed herein along with their countermeasures. An analysis of project-related data reveals that latest techniques and approaches considering rock mechanics were used to complete the project; the existing approaches and methods were accordingly verified and extended. Apart from ground composition, the excavation methods used play an important role in the occurrence of severe rock bursts. Thus, the findings of this study are expected to be helpful for future tunneling projects in the Himalayas.
서울시는 도심지 교통체증을 해결하기 위해 최근 경부고속도로의 일부 구간을 복층터널로 계획하는 방안을 검토하고 있다. 도심지에 복층터널을 건설할 경우, 교통난 해소뿐만 아니라 말레이시아 스마트 터널과 같이 홍수 시 침수방지를 위한 저류시설로도 활용할 수 있을 것으로 본다. 그러나 도로터널을 복층터널로 계획할 경우에는 각 지역을 연결하는 분기터널이 필요하며, 분기터널은 토피가 낮은 구간에 편평율이 큰 대단면 또는 복잡한 터널 단면형상으로 이루어지게 된다. 이때 토피가 낮은 지역에서는 지하 공동구나 건물 기초 등에 인접하여 위치하게 되며 터널 건설로 인해 지장물에 미치는 영향에 대해 반드시 검토해야 한다. 본 연구에서는 복층터널에서 분기되는 터널 굴착 시, 지하 공동구에 미치는 영향을 수치해석을 통해 분석하였다. 변위조절모델(Displacement Controlled Model)을 이용하여 터널 주변의 지반손실률을 1.0%, 3.0%, 그리고 5.0%까지 모사하였다. 복층터널에서 분기되는 각도를 $45^{\circ}$와 $36^{\circ}$로 다르게 설정하여 공동구 측면 및 하부로의 접근을 고려할 수 있도록 하였다. 그 결과, 일반적으로 분기터널이 공동구에 근접할수록 그리고 지반손실률이 클수록 변위, 각변위 그리고 안정성에 미치는 영향이 큰 것으로 타나났다. 공동구 바닥부의 침하와 공동구 부재의 안정성에는 이격거리 보다는 공동구의 하부에 근접하여 큰 변위와 부등침하를 유발할 수 있는 각도 $36^{\circ}$, 이격거리 10 m가 가장 취약한 것으로 나타났다. 본 연구를 통해 근접시공 시 구조물의 안정성 평가를 위한 각변위-거리/직경 관계를 제시하였으며, 지하 공동구 안정성에 영향을 미치는 한계 임계 지반손실률을 산정하였다. Government plans to construct a double-deck tunnel under a portion of Gyeongbu Expressway that will solve traffic problems and could also be used as a flood storage facility. Divergence tunnels connect the main tunnel to the urban areas and their construction effects on adjacent structures at shallow depth need to be analyzed. This study primarily includes the numerical analysis of construction effects of divergence tunnels on utility tunnels. The utility tunnel was analyzed for three cases of volume loss applied to the divergence tunnel and two cases of the angle between main tunnel and divergence tunnel ($36^{\circ}$ and $45^{\circ}$). The results show that the more the volume loss was applied and the shorter the distance was between utility tunnel and divergence tunnel, the more the utility tunnel was affected in terms of induced displacements, angular displacement and stability. The worst scenario was found out to be the one where the angle between main tunnel and divergence tunnel was $36^{\circ}$ and the distance between divergence tunnel and utility tunnel was 10 m, resulting in the largest displacement and differential settlement at the bottom of the utility tunnel. A relationship between the angular displacement and the distance to diameter ratio was also established.
Owing to several advantages, mechanical pre-cutting techniques were first introduced in the United States and subsequently used in Europe for tunneling. Pre-cutting machines perform mechanical excavation tunneling using cutting tools such as tunnel boring machines (TBMs) and roadheaders. Linear cutting tests are reliable and widely used to predict the performance of TBMs and roadheaders. In this study, the effect of the cutting tool shape of a pre-cutting machine was analyzed using linear cutting tests. Assuming the basic shape of the tool, the clearance and rake angles of the tool were designated as variables that determine the shape. The experimental results for samples with different mechanical properties were analyzed considering the cutting force, cutting volume, and specific energy, which were inversely related to the clearance angle. Initially, the force decreased significantly as the clearance angle increased from 0° to 5°, and then converged at angles of 10° and higher. However, the cutting volume decreased linearly with angles. The specific energy behaved similarly to the force. Compared with the clearance angle, the rake angle slightly affected the cutting force, volume, and specific energy. When the rake angle increased from 0° to 5°, the cutting force and volume decreased slightly; however, both increased after 5°. The specific energy exhibited a similar trend.
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