• Title, Summary, Keyword: 토압

Search Result 484, Processing Time 0.041 seconds

Estimation of Earth Pressures Acting on Box Structures Buried in Ground (지중에 매설된 박스구조물에 작용하는 토압 산정)

  • Hong, Won-Pyo;Yun, Jung-Mann;Song, Young-Suk
    • Journal of the Korean Geosynthetics Society
    • /
    • v.14 no.2
    • /
    • pp.23-33
    • /
    • 2015
  • The earth pressure acting on underground structure was measured by application of the instrumentation system in the subway construction site constructed by the method of cut-and-cover tunnel. The measured earth pressure was compared with the earth pressure obtained from the existed theoretical equation, and the actual earth pressure diagram acting on the underground structure was investigated. As a result of investigation, the vertical earth pressure is mainly affected by the embankment height, and the lateral earth pressure is significantly affected by whether the existence of earth retaining structures or not. The measured vertical earth pressure is very similar to the theoretical earth pressure proposed by Bierbaumer. The measured lateral earth pressure is closed to the active earth pressure proposed by Rankine rather than the earth pressure at rest. The coefficient of earth pressure in soil deposit layer is about 0.35, and the coefficient in soft rock deposit layer is about 0.21. For design and construction the underground structures, therefore, it is reasonable estimation that the lateral earth pressure acting on structures installed in soil deposit layers is an average value between active earth pressure and earth pressure at rest. In rock deposit layers, the lateral earth pressure acting on structure is an active earth pressure only.

Earth Pressuroes of Tieback Walls in Sand (사질토에 시공된 앵커토류벽의 토압분포에 관한 연구)

  • 김낙경
    • Geotechnical Engineering
    • /
    • v.14 no.5
    • /
    • pp.17-28
    • /
    • 1998
  • The design of a ground anchor wall calculating the design anchor force and anchored walls depends primarily on the earth pressure acting on anchored w deflection of the wall, the wall stiffness, distribution exists for anchored walls. In the apparent earth pressure envelope design of anchored walls. In this study, full scale anchored w pressure distribution was obtained from function. Earth pressures obtained from pressure and with the apparent earth pre the anchored wall in sand. It is conclude is appropriate for the anchored wall design.

  • PDF

Earth Pressure Acting on Rigid Retaining Wall due to the Dynamic Load (동하중에 의한 강성벽체에 작용하는 토압)

  • 박종덕;전용백
    • Journal of the Korean Geotechnical Society
    • /
    • v.16 no.5
    • /
    • pp.157-168
    • /
    • 2000
  • 토류구조물의 안정문제로는 장단기적으로 정적인 경우와 동적인 경우, 그리고 지반의 동적 거동특성, 흙의 강도저하 등을 미리 파악하여 기술적인 대처를 할 필요가 있을 것이다. 본 연구에서는 실내 모형 실험을 통하여 구조물의 배면에 토성이 다른 일반모래, 표준모래, 점성토를 뒷채움하여 다짐없이 강사만 하고, 룰러다짐, 진동다짐을 하여 토피의 수평 진동거리를 길게, 짧게 그리고 중간으로 하여 강성벽체에 작요?는 수평토압에 대한 정적, 동적 특성을 규명하는 것이다. 모형 실험장치로는 실험대, 토조, 토압측정장치, 진동하중 발생장치, 진동측정장치, 강사기, 롤러 등을 설치하여 거리에 따른 병진운동으로 가속도와 수평토압, 수평토압계수, 전체토압, 토압의 작용점, 지진토압증분 증을 구하여, 실험결과와 기존 이론결과, 그리고 유한요소 해석결과와 비교 고찰하였다.

  • PDF

A rational estimating method of the earth pressure on a shaft wall considering the shape ratio (벽체형상비의 영향을 합리적으로 고려한 원형수직구 벽체에 작용하는 토압산정방법)

  • Shin, Young-Wan;SaGong, Myung
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.9 no.2
    • /
    • pp.143-155
    • /
    • 2007
  • The earth pressure acting on a circular shaft wall is smaller than that acting on the wall in plane strain condition due to the three dimensional axi-symmetric arching effect. Accurate estimation of the earth pressure is required for the design of the shaft wall. In this study, the stress model considering the decrease of earth pressure due to the horizontal and vertical arching effect and the influence of shape ratio (shaft height/radius) is proposed. In addition, model test on the sandy soil is conducted and a comparison is made between the stress model and the test results. The comparison shows that the proposed stress model is in agreement with test results; decrease of shape ratio (increase of radius) leads to stress state equal to the plane strain condition and approximate stress distribution is found between stress model and model test results.

  • PDF

The Lateral Earth Pressure on Rigid Retaining Wall Due to the Various Modes of Wall Movement (벽체변위에 따른 기류벽에 작용하는 토압)

  • Chae, Yeong-Su;Im, Byeong-Ju;Baek, Yeong-Sik
    • Geotechnical Engineering
    • /
    • v.1 no.1
    • /
    • pp.21-30
    • /
    • 1985
  • The reasonable static and dynamic earth pressure equations were developed by applying the Dubrova's theory and Chang's method to the following cases of wall movements; (1) Active case rotating about the top (2) Active case rotating about the bottom (3) Passive case rotating about the top (4) Passive case rotating about the bottom The equations are presented in accordance with particular wall displacements for the sand and cohesive back-fill, respectively. The results computed by the proposed equations are compared with the conventional theoretical values.

  • PDF

Study on Earth Pressure Acting Against Caisson Structure with the Heel (뒷굽이 있는 케이슨 안벽에 작용하는 토압에 대한 연구)

  • Yoo, Kun-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.29 no.2
    • /
    • pp.67-76
    • /
    • 2017
  • In this study, the effect of caisson heel on the active earth pressure is investigated. Using limit analysis method, inclinations of slip surface developed above the heel with different lengths are analyzed. The shorter the heel length, the larger those of inside slip surface, however those of outside slip surface are not changed. According to the relative heel length, relationships of internal friction angle of backfill material - wall friction angle between caisson structure and backfill - friction angle acting on virtual section at the end of heel are presented. Earth pressures acting against caisson structure with relatively short heel are smaller than Rankine earth pressure but always greater than Coulomb earth pressure which does not consider the heel length.

Load Transfer to the Adjacent Ground Induced by the 3-Dimensional Active Displacement (3차원 주동변위에 따른 인접지반으로의 하중전이)

  • Park, Byung Suk;Lee, Sang Duk
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.10
    • /
    • pp.49-60
    • /
    • 2015
  • Since previous studies on the 3-dimensional earth pressure have been conducted focusing on the stability of wall, it is very difficult to find a study on the load transfer to the adjacent ground induced by the 3-dimensional active displacement. Therefore, in this study, we tried to find out the load transfer to the adjacent ground induced by the 3-dimensional active displacement depending on the size of rectangular wall which was defined by the aspect ratio, that is, the ratio of the height to the width of the wall. 3-dimensional model tests were performed in order to measure the distribution and the magnitude of load transfer to surrounding grounds. The transferred load was 17.9~30.6% less than the difference between the 3-dimensional active earth pressure and earth pressure at rest. The transferred load of both vertical and horizontal was maximum at the boundary of the active wall. The load transfer range depended on the normalized height of the active wall, and it was 0.67~1.29w in horizontal direction and 1.0~3.0h in vertical direction. The transferred load in horizontal was maximum at the height of the wall. As the aspect ratio increases the location of the maximum transferred load points becomes higher. The ratio of the transferred load area of 56~79% at 0.25w in horizontal direction and 50~58% at 1.0~1.5 in vertical direction. Diagrams showing the distribution and the magnitude of the transferred load depending on the aspect ratio were suggested.

Nonlinearly Distributed Active Earth Pressure on a Translating Rigid Retaining Wall : II. Application (평행이동하는 강성옹벽에 작용하는 비선형 주동토압 : II. 적용성)

  • 백규호
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.1
    • /
    • pp.191-199
    • /
    • 2003
  • It is known that the distribution of the active earth pressure against a rigid wall is not triangular, but nonlinear, due to arching effects in the backfill. In the farmer paper, a new formulation was proposed for the nonlinear distribution of active earth pressure on a translating rigid retaining wall considering arching effects. In this paper, parametric study is performed to investigate the effect of ${\phi}, {\delta}$ and wall height on the magnitude and distribution of active earth pressure calculated from the proposed equations. In order to check the accuracy of the proposed formulation, the predictions from the equation are compared with both existing full-scale test results and values from existing equations. The comparisons between calculated and measured values show that the proposed equations satisfactorily predict both the earth pressure distribution and the lateral active earth force on the translating wall. Simplified design charts are also proposed for the modified active earth pressure coefficient and fur the height of application of the lateral active force in order to facilitate the use of the proposed equation.

A study on eccentric load acted on cut and cover tunnel by numerical approach (복개 터널구조물에 작용하는 편토압 고려를 위한 수치해석적 연구)

  • Bae, Gyu-Jin;Chung, Hyung-Sik;Lee, Gyu-Phil
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.5 no.3
    • /
    • pp.227-239
    • /
    • 2003
  • For environment-friendly construction, cut-and-cover tunnels have been constructed, thereby leading to embankment slopes with a number of steps. The slopes cause eccentric load on concrete lining of the tunnel. Nevertheless, uniform vertical and horizontal earth pressures, which are determined by considering a self-weight of embankment and $K_0$, are routinely used in structural calculation. Distribution of the earth pressures applied to the lining will lead to a biased calculation far from the actual behavior of the lining. In this study, basic study, therefore, was performed to consider the eccentric load properly in design and analysis of a cut-and-cover tunnel. A method capable of considering the eccentric load in design was proposed and its applicability was numerically examined through a number of examples.

  • PDF

Reduction of Horizontal Earth Pressure on Retaining Structures by a Synthetic Compressible Inclusion (압축성재료를 이용한 콘크리트 옹벽의 수평토압 저감방안에 대한 연구)

  • Yoo, Ki-Cheong;Paik, Young-Shik;Kim, Ho-Bi;Kim, Khi-Woong
    • Journal of the Korean Geoenvironmental Society
    • /
    • v.4 no.1
    • /
    • pp.19-28
    • /
    • 2003
  • Current methods for lateral thrust calculations are based on the classical formulations of Rankine or Coulomb. However, the previous studies indicate that lateral earth pressures acting on the wall stem, which is the function of deformation parameters of the backfill, are close to the active condition only in the top half of the wall stem and in the lower half of the wall stem, the lateral earth pressures are significantly in excess of the active pressures. This paper presents the compressible inclusion function of EPS which can results in reduction of static earth pressure by accomodating the movement of retained soil. A series of model tests were conducted to evaluate the reduction of static earth pressure using EPS inclusion and determine the optimum stiffness of EPS. Also, field test was conducted to evaluate the reduction of static earth pressure using EPS inclusion. Based on field test it is found that the magnitude of static earth pressure can be reduced about 20% compared with classical active earth pressure.

  • PDF