Effect of Rock Mass Condition on the Earth Pressure Against an Excavation Wall in Rock Mass: Numerical Investigation

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(1)한국지반공학회논문집 제33권 11호 2017년 11월 pp. 83 ～ 95 JOURNAL OF THE KOREAN GEOTECHNICAL SOCIETY Vol.33, No.11, November 2017 pp. 83 ～ 95. ISSN 1229-2427 (Print) ISSN 2288-646X (Online) https://doi.org/10.7843/kgs.2017.33.11.83. 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사 Effect of Rock Mass Condition on the Earth Pressure Against an Excavation Wall in Rock Mass: Numerical Investigation 손 무 락. 1. Son, Moorak 2. Adedokun, Solomon. Abstract This study examined the magnitude and distribution of earth pressure on the excavation wall in jointed rock mass by considering different groundwater conditions under various rock types, joint inclination angles, and earth pressure coefficients. Based on a physical model test (Son and Park, 2014), extended studies were conducted considering rock-structure interactions based on the discrete element method, which can consider the joints characteristics of rock mass. The results showed that the earth pressure was highly influenced by the groundwater condition as well as the rock type, joint inclination angle, and earth pressure coefficient. The results were also compared with Peck’s earth pressure for soil ground, and clearly showed that the earth pressure in jointed rock mass can be greatly different from that in soil ground.. 요. 지. 본 연구는 절리가 형성된 암반지층에서 암석종류, 절리경사각, 토압계수 및 지하수조건을 달리할 때 굴착벽체에 발생하는 토압의 크기 및 분포에 대해서 조사하였다. 모형실험(Son and Park, 2014)에 근거하여 확장연구를 수행하였 으며, 이 때 암반-구조 상호작용과 암반의 절리특성을 고려하기 위하여 개별요소법을 이용한 수치해석을 수행하였다. 본 연구로부터 굴착벽체에 작용하는 토압은 암석종류, 절리경사각 및 토압계수 뿐만 아니라 지하수조건에 의해서 크게 영향을 받는다는 것을 파악하였다. 이와 더불어 본 연구로부터 조사된 토압을 토사지반에 적용되는 Peck의 경험 토압과 비교하였으며, 이를 통해 절리형성 암반지층 굴착벽체에 발생하는 토압은 토사지반에서 발생하는 토압과 크게 다를 수 있다는 것을 확인하였다. Keywords : Rock excavation, Excavation wall, Earth pressure, Groundwater, Earth pressure coefficient, Rock type, Joint inclination angle, Rock-structure interaction. 1 정회원, Member, Prof., Dept. of Civil Engrg., Daegu Univ., Tel: +82-53-850-6527, [email protected], Corresponding author, 교신저자 2 비회원, Former Graduate Student, Dept. of Civil Engrg., Daegu Univ. * 본 논문에 대한 토의를 원하는 회원은 2018년 5월 31일까지 그 내용을 학회로 보내주시기 바랍니다. 저자의 검토 내용과 함께 논문집에 게재하여 드립니다.. Copyright © 2017 by the Korean Geotechnical Society This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.. 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 83.

(2) including rocks (Chae and Moon, 1994; Jeong and Kim,. 1. Introduction. 1997; Yoo and Kim, 2000). These studies only compare The impact of deep excavation works on the surround-. the earth pressure measured in multi-layered soils with. ing environment has become a major concern. To minimize. Peck’s earth pressure and the effect of groundwater and. excavation-related problems such as wall collapse and to. earth pressure coefficient as well as joint condition (joint. maximize economic efficiency for support design, it is. inclination angle and joint shear strength) were not. necessary to clearly understand the behavioral characteristics. examined. Few studies have examined the earth pressure. of the ground and excavation walls and to have a clear. in rock strata by considering ground-wall interactions. understanding of ground-wall interactions.. and joint characteristics, which are important factors. The earth pressure on the excavation walls caused by deep. influencing the magnitude and distribution of the earth. excavation works have been studied by many researchers. pressure in jointed rock mass. This might be due to the. through field measurements and physical model tests.. general misunderstanding that rock strata represent a better. Fig. 1 shows apparent earth pressure envelopes suggested. condition than soil ground. Recently, to better understand. by Peck (1969) and Tschebotarioff (1973), which are. the earth pressure on an excavation wall in jointed rock. frequently used in practice for designing excavation walls. mass, Son (2013), Son and Park (2014), and Son and. soil ground. However, the existing studies were mainly. Adedokun (2015) presented physical and numerical study. carried out on sandy and clayey soils though ground is. results of the earth pressures in jointed rock mass, con-. made up of not only soils but also rocks. Nevertheless,. sidering various rock, joint, and support conditions. The. there are also some studies which measured the earth. results clearly showed that the earth pressure can be. pressure on the excavation walls in multi-layered ground,. higher for rock strata than soil ground when the rock. (a) Apparent earth pressure (Peck, 1969). (b) Apparent earth pressure (Tschebotarioff, 1973) Fig. 1. Apparent earth pressure for soils. 84. 한국지반공학회논문집 제33권 제11호.

(3) and joint characteristics are under unfavorable conditions,. are expected to provide a better understanding of the. such as a joint condition that induces sliding and a. earth pressure on the excavation wall in a jointed rock. weathered joint and rock condition. On the other hand,. mass that can experience different rock mass coditions.. the earth pressure might be much lower than the soil ground when the rock and joint conditions are favorable. This study extended the previous study (Son et al.,. 2. Numerical Approach and Extended Parametric Study. 2015), focusing on the effect of groundwater condition under different rock type, joint inclination angle, and. The applied numerical approach in this study is similar. earth pressure coefficient. Extended numerical parametric. to the previous study (Son and Park, 2014), and the. studies were conducted by varying the groundwater con-. following gives a brief description. The approach was. dition together with the rock type, joint inclination angle,. verified by the numerical simulation of a physical model. and earth pressure coefficient. The results from this study. test (Figs. 2 and 3). The numerical approach was extended. Fig. 2. Test preparation for physical model (Son and Park, 2014). Fig. 3. Comparison between physical model test and numerical simulation (Son and Park, 2014). 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 85.

(4) Table 1. Controlled parameters for numerical analyses Parameters Rock type. Groundwater condition. Joint inclination angle (°). Joint shear condition. Earth pressure coefficient. Hard. NG*, GWIW**. 30, 60. Good. 0.5, 1, 2, 3. Slightly weathered. NG, GWIW. 30, 60. Fair. 0.5, 1, 2, 3. Moderately weathered. NG, GWIW. 30, 60. Poor. 0.5, 1, 2, 3. *: No groundwater, **: Groundwater with impermeable wall. to this parametric study, which considered the effect of different groundwater condition (no groundwater and groundwater with an impermeable wall) and earth pressure coefficient as well as rock types and joint inclination angles on the magnitude and distribution of earth pressure against the excavation wall in jointed rock masses. Table 1 summarizes the consider conditions in this study. The (a) No groundwater condition. groundwater table was assumed to be at the ground surface. To assess the characteristics of rock masses governed by joints, this study adopted 2-D Universal Distinct Element Code (UDEC, 2004), which allows for large displacements between blocks. The rock blocks, wall and struts were simulated as separate elastic elements. The joints between the rock blocks and the interfaces between walls and rocks were modeled using the Coulomb slip model in which when the contact shear stress exceeds. (b) Groundwater condition Fig. 4. Numerical modeling (a case of joint inclination angle of 60°). the contact shear strength the contact loses strength and sliding occurred. A fully coupled mechanical-hydraulic. shown below.. analysis was performed, in which joint porewater pressures affected the mechanical computations. The coupled behavior was examined using the method of fluid flow in joints. Strut sti f fness . EA. cos   L × Space. provided by the DEM code. The analysis model was 68.8 m × 31.5 m and the. where A is the cross sectional area of the strut, E is. excavation wall was installed at the depth of 20.5 m. the elastic modulus of the strut, L is the half of the. (Fig. 4). The excavation width was assumed to be 20. strut length, Space is the strut horizontal spacing, θ is. m and the final excavation depth was 19 m. A strut-. the installation angle of the strut (zero in horizontal. supported system was used because the apparent earth. installation).. pressure (Peck, 1969), which was compared with this. The joint inclination angle was measured in the anti-. paper’s results, was obtained from many sets of compre-. clockwise direction from the horizontal plane, and the. hensive measurements of the strut load in strut-supported. joint spacing was assumed to be 1 m. For each of the. excavation walls for soil ground.. cases, the analysis was carried out using soldier pile and. The strut stiffness (80 MN/m/m), which is a typical. timber lagging wall. In order to reflect the general exca-. struct stiffness of the vertical spacing of 3 m, was. vation procedures in the field, eight excavation stages. determined from the properties of the strut member as. were conducted to obtain the distribution and magnitude. 86. 한국지반공학회논문집 제33권 제11호.

(5) Fig. 5. Excavation stages in numerical modeling (a case of joint inclination angle of 60°). of earth pressure. Before the first excavation was carried out, the initial equilibrium was obtained with the at-rest earth pressure coefficient. At this stage, the boundary condition was a roller at each end of the two vertical boundaries and at the bottom boundary. After ensuring the initial equilibrium condition, all displacements were reset to zero and the wall was installed at a depth of 20.5 m. The first excavation was conducted up to 1.0. Fig. 6. Transformed section in numerical modeling. the equivalent flexural stiffness of the wall (see Fig. 6) using the method as shown below.. m, followed by the installation of the first strut at 0.5.  ×    ×   . m over the excavation line. After the first excavation, there was additional excavation work every 3 m, which. where Ep is the elastic modulus of the soldier pile, El. was followed by the strut installation at every 3 m interval. is the elastic modulus of the timber lagging, Et is the. (which is 0.5 m above each excavation line). Wall stabili-. elastic modulus of the transformed section, Ip is the. zation was ensured after each excavation stage. The. second moment inertia of the soldier pile, Il is the. final excavation was conducted up to 19.0 m, and no. second moment inertia of the timber lagging, It is the. strut was installed in the final stage (see Fig. 5). Other. second moment inertia of the transformed section, Np. analyses were also carried out for different groundwater. is the number of the soldier pile per unit meter, and. conditions and earth pressure coefficients using the same. Nl is unity.. procedures discussed above.. Table 2 shows the properties of the wall, rocks, joints,. The shape of typical excavation wall (i.e. soldier pile. and interfaces used in numerical analysis. The assessment. and timber lagging wall) might have little effect on the. of the properties was discussed in detail by Son and. earth pressure and wall displacement in the field as long. Yoon (2011).. as the flexural stiffness of the wall is equivalent. However, in a numerical analysis the shape may have a considerable. 3. Effect of Rock Mass Conditions. influence on the results because of a stress concentration in modeling. To address this issue, this study transformed. Figs. 7 and 8 compare the distributions of the apparent. the excavation wall into a simple section to represent. earth pressures induced on the excavation walls for hard. 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 87.

(6) Table 2. Properties of the wall, rocks, joints and interfaces used in the analysis Rock type. Moderately weathered. Rock. EtIt Er (MPa.m4) (MPa). Hard Slightly weathered. Rock and joint. Wall. 23.20. υ. Rock-Wall interface. Joint γr Joint c,σt (MN/m3) condition (MPa). . r. (°). (°). kn ks (MPa/m) (MPa/m). a (m). ares (m). μ c,σt (Pa.sec) (MPa). δ (°). ks ks (MPa/m) (MPa/m). 1.0x105 0.2 2.7x10-2. Good. 0. 50. 35. 2.33x105 0.96x105 3x10-4 2x10-4. 10-3. 0. 33. 2.33x105 0.96x105. 1.0x104 0.22 2.6x10-2. Fair. 0. 40. 32. 2.33x104 0.96x104 3x10-4 2x10-4. 10-3. 0. 27. 2.33x104 0.96x104. 1.0x103 0.25 2.5x10-2. Poor. 0. 35 31.5 2.33x103 0.96x103 3x10-4 2x10-4. 10-3. 0. 23. 2.33x103 0.96x103. EtIt = Wall bending stiffness of transformed section; Er = Intact rock elastic modulus; υ = Poisson’s ratio; γr = Unit weight of intact rock; c = Joint or interface cohesion; σt =Joint or interface tensile strength;  = Joint friction angle;  r = Joint residual friction angle; δ = Interface friction angle; kn = Joint or interface normal stiffness; ks = Joint or interface shear stiffness; a = Joint aperture; ares = Joint residual aperture; μ = Dynamic viscosity of water. rock at the joint inclination angles of 30° and 60° respec-. envelope) of the induced earth pressures from numerical. tively under different groundwater conditions and at-rest. analysis with that from Peck’s empirical earth pressure. earth pressure coefficients. In the figures, the induced. for the sand ground varying joint inclination angle.. earth pressures were represented in terms of apparent. For a joint inclination angle of 30°, the apparent earth. earth pressures in which the magnitude and distribution. pressure ratio was the highest at the top part of the. of earth pressures on the excavation wall were inferred. excavation wall and decreased along depth under no. from the strut axial loads in the same way as Peck (1969).. groundwater condition regardless of the at-rest earth. In addition, the induced apparent earth pressures in jointed. pressure coefficient. The total earth pressure ratios ranged. rock masses were compared with Peck’s apparent earth. from 0.02 to 0.11. In contrast, the earth pressures of. pressure for sand ground with a friction angle of  =. the groundwater condition with an impermeable wall. 35°. The medium dense sand ground with a friction angle. increased significantly and proportionately to the at-rest. of  = 35° was simply chosen because the empirical earth. earth pressure coefficient. The increase in earth pressure. pressure envelope by Peck for the ground is relatively. under the condition with groundwater can be attributed. simple and can be compared directly and easily with. to the increase in joint shear stress due to the joint. the results of numerical parametric studies for jointed. inclination and the decrease in joint shear strength due. rock masses. The apparent earth pressure ratio in the. to the pore water pressure induced by the groundwater. figures represents the ratio of the induced earth pressure. table at the ground surface. The earth pressure was also. for jointed rock mass to Peck’s earth pressure for the. higher at the upper part of the wall under the ground-. sand ground. It is quite meaningful to compare the results. water condition and it decreased along depth. The total. of the earth pressures in this study with a specific soil. earth pressure ratios ranged from 0.4 for an earth pressure. ground because a practitioner can obtain useful and. coefficient of 0.5 to 0.92 for an earth pressure coefficient. intuitive information of the earth pressures in jointed. of 3.0.. rock masses by simply comparing with the soil earth. These results suggest that the earth pressure in a jointed. pressure. A practitioner can easily estimate the earth. rock mass is strongly dependent on the groundwater. pressure in a jointed rock mass using the normalized. condition, at-rest earth pressure coefficient, and joint. earth pressure ratios between the jointed rock masses. inclination angle.. and the sand ground with a friction angle of 35°. Fig.. For a joint inclination angle of 60°, where joint sliding. 9 compares the total earth pressure ratios (the area of. was induced, the apparent earth pressures under no ground-. an induced apparent earth pressure distribution envelope. water condition were significantly higher than those of the. divided by the area of Peck’s apparent earth pressure. joint inclination angle of 30° under the same condition.. 88. 한국지반공학회논문집 제33권 제11호.

(7) Fig. 7. Comparison of the apparent earth pressures for hard rock (joint inclination angle: 30°). Fig. 8. Comparison of the apparent earth pressures for hard rock (joint inclination angle: 60°). 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 89.

(8) (a) Joint inclination angle: 30°. (b) Joint inclination angle: 60°. Fig. 9. Comparison of the total earth pressure ratios between the numerical tests and Peck’s empirical method (Hard rock). The effects of the earth pressure coefficient were not. pressure ratio was also the highest at the top part of the. significant when joint sliding was induced (see Figs. 8. excavation wall and decreased along depth under no. and 9). In addition, the apparent earth pressure ratio was. groundwater condition regardless of the at-rest earth. the highest at the top part of the excavation wall under. pressure coefficient. But the apparent earth pressures for. no groundwater condition and decreased along depth but. all the earth pressure coefficients were significantly higher. it tended to increase along depth under the groundwater. when compared to those of hard rock with a joint in-. condition with an impermeable wall. The total earth. clination angle of 30°. The total earth pressure ratios. pressure ratios ranged from 0.74 for an earth pressure. of the no groundwater ranged from 0.13 for an earth. coefficient of 0.5 to 0.75 for an earth pressure coefficient. pressure coefficient of 0.5 to 0.83 for an earth pressure. of 3.0. The earth pressures of the groundwater condition. coefficient of 3.0. For the groundwater condition with. with an impermeable wall increased significantly, but they. an impermeable wall, the earth pressure distribution was. were irrelevant to the at-rest earth pressure coefficient. similar to hard rock in shape, but the magnitude of the. due to the effect of joint sliding. The total earth pressure. induced earth pressure was much higher and the total. ratios ranged from 1.78 for an earth pressure coefficient. earth pressure ratios ranged from 0.88 to 1.21.. of 0.5 to 1.80 for an earth pressure coefficient of 3.0.. The results suggested that the effects of groundwater. These results suggested that joint sliding increased. on the earth pressure decreased with increasing at-rest. the earth pressure significantly but it decreased the effects. earth pressure coefficient, Ko. This is different from hard. of the earth pressure coefficient.. rock, where the effect was opposite. In other words, the. Figs. 10 and 11 compare the distributions of the apparent earth pressures induced on the excavation walls for slightly. effects of groundwater on earth pressure are influenced by the rock and joint conditions.. weathered rock at the joint inclination angles of 30° and. For a joint inclination angle of 60°, where joint sliding. 60° respectively under different groundwater conditions. was induced, the apparent earth pressures under the no. and at-rest earth pressure coefficients. In addition, the. groundwater condition were higher than those of the. apparent earth pressures were compared with Peck’s. joint inclination angles of 30° under the same condition.. apparent earth pressure for sand ground with a friction. A more significant increase took place at lower earth. angle of  = 35°. Fig. 12 compares the total earth pressure. pressure coefficients (see Figs. 11 and 12). The effects. ratios of the induced earth pressures from numerical. of the earth pressure coefficient were less significant when. analysis with that from Peck’s empirical earth pressure. joint sliding was induced. In addition, the apparent earth. for the sand ground varying joint inclination angle.. pressure ratio was highest at the top part of the exca-. For a joint inclination angle of 30°, the apparent earth. 90. 한국지반공학회논문집 제33권 제11호. vation wall under no groundwater condition and decreased.

(9) Fig. 10. Comparison of the apparent earth pressures for slightly weathered rock (joint inclination angle: 30°). Fig. 11. Comparison of the apparent earth pressures for slightly weathered rock (joint inclination angle: 60°). 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 91.

(10) (a) Joint inclination angle: 30°. (b) Joint inclination angle: 60°. Fig. 12. Comparison of the total earth pressure ratios between the numerical tests and Peck’s empirical method (Slightly weathered rock). along depth, which was also observed in hard rock, but. The effects of groundwater on the earth pressure were. it was similar along depth under the groundwater condition. much lower than those of hard and slightly weathered. with an impermeable wall. For no groundwater condition. rocks and there was no groundwater effect at the high. the total earth pressure ratios ranged from 0.81 for earth. earth pressure coefficients of 2.0 and 3.0. The apparent. pressure coefficients of 0.5 to 1.1 for an earth pressure. earth pressure ratio was the highest at the middle part. coefficient of 3.0. The earth pressures of the groundwater. of the excavation wall regardless of the earth pressure. condition with an impermeable wall were much high. coefficient and groundwater conditions. The total earth. and the total earth pressure ratios ranged from 1.7 to. pressure ratios between the induced earth pressure and. 1.8, which were similar to those of hard rock for the. Peck’s earth pressure ranged from 0.65 (1.31 for the. groundwater condition with an impermeable wall.. groundwater condition with an impermeable wall) for. Figs. 13 and 14 compare the distributions of the. an earth pressure coefficient of 0.5 to 3.93 (3.93 for. apparent earth pressures induced on the excavation walls. the groundwater condition with an impermeable wall). for moderately weathered rock at the joint inclination. for the earth pressure coefficient of 3.0.. angles of 30° and 60° respectively under different ground-. For a joint inclination angle of 60°, although joint. water conditions, wall permeability conditions, and at-rest. sliding was induced and more evident increase occurred. earth pressure coefficients. In addition, the apparent earth. at lower earth pressure coefficients (see Figs. 14 and. pressures were compared with Peck’s apparent earth. 15), the apparent earth pressures were relatively similar. pressure for sand ground with a friction angle of  =. to those of the other joint inclination angles, which was. 35°. Fig. 15 compares the total earth pressure ratios of. different from the hard and slightly weathered rocks.. the induced earth pressures from numerical analysis with. These results suggest that the effects of joint sliding. that from Peck’s empirical earth pressure for the sand. decreased as the rock and joint conditions deteriorated.. ground varying joint inclination angle.. The effects of groundwater on the earth pressure were. For a joint inclination angle of 30°, the induced earth. similar to those of the joint inclination angle of 60°. For. pressures for all the earth pressure coefficients were signi-. no groundwater condition, the apparent earth pressure. ficantly higher than those of hard and slightly weathered. ratio tended to be high at the middle part of the excavation. rocks due to the higher tendency of block displacement. wall regardless of the earth pressure coefficient and. in moderately weathered rock. The results showed that. groundwater conditions, but it depended on the earth. earth pressures increased constantly with the increase. pressure coefficient under the groundwater condition with. of the earth pressure coefficient and the increase rate. an impermeable wall. The total earth pressure ratios. was much higher than that in slightly weathered rock.. between the induced earth pressure and Peck’s earth. 92. 한국지반공학회논문집 제33권 제11호.

(11) Fig. 13. Comparison of the apparent earth pressures for moderately weathered rock (joint inclination angle: 30°). Fig. 14. Comparison of the apparent earth pressures for moderately weathered rock (joint inclination angle: 60°). 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 93.

(12) (a) Joint inclination angle: 30°. (b) Joint inclination angle: 60°. Fig. 15. Comparison of the total earth pressure ratios between the numerical tests and Peck’s empirical method (Moderately weathered rock). pressure ranged from 0.94 (1.79 for the groundwater. was more significant in hard rock and the effect was. condition with an impermeable wall) for an earth pressure. relatively small in moderately weathered rock. In. coefficient of 0.5 to 4.38 (4.38 for the groundwater. moderately weathered rock, the high deformability of. condition with an impermeable wall) for an earth pressure. the rock and joint decreased the effect of joint. coefficient of 3.0. For moderately weathered rock the. inclination angle and groundwater.. highest apparent earth pressure ratio was observed at. (4) When the joint inclination angle was 30° in hard. the middle part of the wall regardless of groundwater. rock and good joint conditions, the induced earth. and joint sling conditions.. pressure under groundwater condition increased significantly with the increase of earth pressure coefficient,. 4. Conclusions. but the effect of earth pressure coefficient on the induced earth pressure was very small when joint. The magnitude and distribution of the earth pressure. sliding was induced. On the other hand, when the. on the excavation wall in jointed rock masses were investi-. rock and joint conditions were moderately weathered,. gated. The controlled parameters included groundwater. the effect of groundwater on the induced earth pressure. condition, rock type, joint condition, and earth pressure. was only evident at a lower earth pressure coefficient. coefficient. The following conclusions were made:. regardless of the joint inclination angle. (5) Apparent earth pressure ratio was higher at the upper. (1) The magnitude and distribution of the earth pressure. part of the excavation wall for hard and slightly. on an excavation wall in a jointed rock mass are. weathered rocks regardless of groundwater condition. highly affected by the groundwater condition and. but the feature disappeared when joint sliding was. earth pressure coefficient, together with the joint. induced at the joint inclination angle of 60°. For. inclination angle and rock type. In addition, the. moderately weathered rock the highest apparent earth. induced earth pressure in a jointed rock mass can. pressure ratio was observed at the middle part of. be significantly different from that in soil ground.. the wall regardless of groundwater and joint sling. (2) As the rock and joint conditions were weathered more,. conditions.. the induced earth pressure increased, the effect of groundwater decreased, the effects of earth pressure. References. coefficient increased, and the effects of joint inclination angles decreased. (3) When joint sliding was induced, the sliding effect 94. 한국지반공학회논문집 제33권 제11호. 1. Chae, Y. S. and Moon, I. (1994), “Earth Pressure on Retaining Wall by Considering Local Soil Condition”, Korean Geotechnical Society, ’94 Fall conference paper, pp.129-138..

(13) 2. Jeong, E. T. and Kim, S. G. (1997), “Case Study of Earth Pressure Distribution on Excavation Wall of Multi-layered Soil”, Korean Geotechnical Society, ’97 spring conference paper, pp. 78-80.. Simulation of Excavation Wall in Jointed Rock Mass”, Canadian Geotech. Journal, Vol.51, No.5, pp.554-569. 8. Son, M. and Yoon, C. (2011), “Characteristics of the Earth Pressure Magnitude and Distribution in a Jointed Rockmass”, Journal of. 3. Peck, R.B. (1969), “Deep Excavations and Tunneling in Soft Ground. State-of-the-Art report”, Proceedings of the 7th International Conference on Soil Mechanics and Foundation Engineering, Mexico City, State-of-the Art Volume, pp.225-290.. Korean Society of Civil Engineers, Vol.31, No.6, pp.203-212. 9. Tschebotarioff, G. P. (1973), Foundations, Retaining and Earth Structures. 2nd Ed., MGH. 10. Universal Distinct Element Code, UDEC (2004), User’s Manual,. 4. Son, M. (2013), “Earth Pressure on the Support System in Jointed. Itasca Consulting Group, Inc., Minneapolis, Minnesota, U.S.A. Rock Mass”, Canadian Geotech. Journal, Vol.50, No.5, pp.493-502.. 11. Yoo, C. S. and Kim, Y. J. (2000), “Deep Excavation in Soil,. 5. Son, M. and Adedokun, S. (2015), “Effect of Support Characteristics. Including Rock with Layers on Retaining Wall and Apparent. on the Earth Pressure in a Jointed Rock Mass”, Canadian Geotech.. Horizontal Displacement of Earth Pressure”, Journal of Korean. Journal, Vol.52, pp.1-12.. Geotechnical Society, Vol.16, No.4, pp.43-50.. 6. Son, M., Adedokun, S., and Hwang, Y. (2015), “Effect of the Earth Pressure Coefficient on the Support System in Jointed Rock. Received : September 27th, 2017. Mass”, Journal of the Korean-Geoenvironmental Society, Vol.. Revised : November 13th, 2017. 16, No.2, pp.33-43.. Accepted : November 14th, 2017. 7. Son, M. and Park, J. (2014), “Physical Model Test and Numerical. 암반지층 굴착벽체 작용토압에 대한 암반조건의 영향: 수치해석적 조사. 95.

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