• Title/Summary/Keyword: 횡방향변위

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Lateral Displacement Analysis of Concrete Electric Pole Foundation Grounds (배전용 콘크리트전주 기초지반의 횡방향변위 분석)

  • Ahn, Tae-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.5
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    • pp.42-49
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    • 2009
  • The effects of various forces acting on concrete pole are analyzed using finite element method how the forces affect on ground displacement. The soil types, wind load location of anchor block embedded depth of pole, and distance between poles are varied to find out effects on lateral displacement. Anchor block is effective when it is located at 1/4 of embedded depth The displacement is decreases as elastic modulus increases. Concrete reinforcement for loosened ground is necessary for double poles because double poles cause large excavation. When embedded depth ratio decrease, lateral displacement increase as closer to ground surface. Large embedded depth is effective to reduce lateral displacement, and the distance between poles is not much large factor.

The Optimum Installation Angle of Reticulated Root Piles under Lateral Loads (횡방.향하중을 받는 그물식 뿌리말뚝의 최적 타설경사각)

  • 이승현;김명모
    • Geotechnical Engineering
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    • v.13 no.4
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    • pp.55-66
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    • 1997
  • In order to investigate the influence of installation angle of reticulated root piles(RRP) on their lateral load capacities, model tests of lateral loads on RRP with various installation angles $0^{\circ}\;, 5^{\circ}\;, 10^{\circ}\;, 15^{\circ}\;, 20^{\circ}\;,and 25^{\circ}$ are carried out. One set of RRP consists of 12 piles which are installed in circular patterns forming two concentric circles, each of which has 6 piles. Each pile made of a steel bar of 5mm in diameter and 350mm in length, is coated with sand until the bar has the diameter of 6.5mm. According to the test results, RRP's response is travily influenced by the displacement level. At low displacement level(1m), lateral load capacity increases as the installation angle is increased. However, the value of the optimum installation angle decreases as the displacement level is increased. In fact, it is found to be $17.5^{\circ}$ at 6mm lateral displacement. The ratios of the lateral resistances for the optimum installation angles to those for the vertical RRP decrease as the lateral displacements are increased. Thus the effect of slant ins angle of RRP is expected to be reduced at higher level of lateral displacement.

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Reliability Evaluation of Lateral Spring Constant Applied in Design of Pile Foundation for Bridge Abutment (교대 말뚝기초 설계 시 적용되는 횡방향 스프링정수의 신뢰성 평가)

  • Do, Jongnam;Kim, Nagyoung;Lee, Hyunseong
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.5
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    • pp.13-21
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    • 2020
  • In this study, the reliability of the lateral spring constant (k1) applied during design of pile foundation for bridge abutment was evaluated. To do this, the reliability of the factors related to the prediction of the lateral displacement of the abutment pile foundation, which was designed based on the displacement method proposed by Chang (1937), was analyzed. The data used for analysis were the design statements of ◯◯ bridge and ◯◯ IC2 bridge. Then, it was derived by comparing with the numerical analysis (p-y analysis) based on the basic data.

Presume of Longitudinal Vibration using Transverse Vibration of the String subject to Parametric Oscillation (매개변수가진에 종속되는 현의 횡방향진동을 이용한 종방향진동의 추정)

  • 김도균;김광준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1993.10a
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    • pp.21-27
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    • 1993
  • 매개변수가진에 종속되는 현의 횡방향진동을 시간영역에서 필터작업, 힐버트 변환과 순간주파수 개념을 도입하여 해석함으로서 종방향의 순간진동변위를 추정하는 방법이 제시되었다. 그리고, 실험을 통하여 이론의 타당성을 검증 하였다. 또한, 모의 실험의 결과 일반적인 현구동계에 있어서는 넓은 적용변 수의 선\ulcorner영역에서 종변위가 횡변위와 분리(decoupling) 되어서 공간적으로 길이에 따르는 선형적인 증가성과 시간적으로 조화적인 주기성을 가진다는 것을 확인함으로서 임의의 위치에서의 종변위를 파악함이 가능하였다.

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Evaluation of Permanent Lateral Displacement of a Cyclic Laterally Loaded Pile in Sandy Soil (모래지반에서 횡방향 반복하중을 받는 말뚝의 영구수평변위 평가)

  • Baek, Sung-Ha;Kim, Joon-Young;Lee, Seung-Hwan;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.33 no.2
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    • pp.17-26
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    • 2017
  • Pile foundations that support offshore structures or transmission towers are dominantly subjected to cyclic lateral loads due to wind and waves, causing permanent displacement which can severely affect stability of the structures. In this study, a series of cyclic lateral load tests were conducted on a pre-installed aluminum flexible pile in sandy soil with three different relative densities (40%, 70% and 90%) in order to evaluate the permanent displacement of a cyclic laterally loaded pile. Test results showed that the cyclic lateral loads accumulated the irreversible lateral displacement, so-called permanent displacement. As the number of cyclic lateral load increased, accumulated permanent displacement increased, but the permanent displacement due to one loading cycle gradually decreased. In addition, the permanent displacement of a pile increased with decrement of relative density and decreased by soil saturation. From the test results, the normalized permanent displacement defined as the cumulative permanent displacement to the initial permanent displacement ratio was investigated, and empirical equations for predicting the normalized permanent displacement was developed in terms of relative density of the soil and the number of cyclic lateral load.

On the Modification of a Classical Higher-order Shear Deformation Theory to Improve the Stress Prediction of Laminated Composite Plates (적층평판의 응력해석 향상을 위한 고전적 고차전단변형이론의 개선)

  • Kim, Jun-Sik;Han, Jang-Woo;Cho, Maeng-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.249-257
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    • 2011
  • In this paper, an systematic approach is presented, in which the mixed variational theorem is employed to incorporate independent transverse shear stresses into a classical higher-order shear deformation theory(HSDT). The HSDT displacement field is taken to amplify the benefits of using a classical shear deformation theory such as simple and straightforward calculation and numerical efficiency. Those independent transverse shear stresses are taken from the fifth-order polynomial-based zig-zag theory where the fourth-order transverse shear strains can be obtained. The classical displacement field and independent transverse shear stresses are systematically blended via the mixed variational theorem. Resulting strain energy expressions are named as an enhanced higher-order shear deformation theory via mixed variational theorem(EHSDTM). The EHSDTM possess the same computational advantage as the classical HSDT while allowing for improved through-the-thickness stress and displacement variations via the post-processing procedure. Displacement and stress distributions obtained herein are compared to those of the classical HSDT, three-dimensional elasticity, and available data in literature.

Development of Device to Resist Horizontal Displacement of Asphalt Concrete Track (아스팔트콘크리트 궤도용 궤도변위 저항 장치 개발)

  • Lee, Seonghyeok;Yoon, Wooyong;Bae, Younghoon
    • Journal of the Korean Society for Railway
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    • v.19 no.6
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    • pp.744-754
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    • 2016
  • Asphalt concrete track (ACT) is a track system connecting wide sleepers and concrete panels on top of an asphalt concrete layer; such a system requires adequate resistance force against various longitudinal and lateral external loads. In this study, a series of experiments were carried out to assess the longitudinal and lateral resistance force of a wide sleeper and concrete panel type ACT. The required shear resistance force of the horizontal displacement restraint device (HDRD) was evaluated. Furthermore, a concrete block type anchor and a steel pipe type anchor were developed as HDRDs. The shear resistance force was decided based on the experimental results of horizontal shear tests for each anchor system. In addition, proper numbers and arrangement design guidelines for the HDRDs were suggested considering the shear resisting capacity and economics for HDRDs applied to ACT.

Efficient Thermal Stress Analysis of Laminated Composite Plates using Enhanced First-order Shear Deformation Theory (일차전단변형이론을 이용한 복합재료 적층평판의 효율적 열응력 해석)

  • Han, Jang-Woo;Kim, Jun-Sik;Cho, Maenghyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.6
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    • pp.505-512
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    • 2012
  • In this paper, an efficient yet accurate method for the thermal stress analysis using a first order shear deformation theory(FSDT) is presented. The main objective herein is to systematically modify transverse shear strain energy through the mixed variational theorem(MVT). In the mixed formulation, independent transverse shear stresses are taken from the efficient higher-order zigzag plate theory, and the in-plane displacements are assumed to be those of the FSDT. Moreover, a smooth parabolic distribution through the thickness is assumed in the transverse normal displacement field in order to consider a transverse normal deformation. The resulting strain energy expression is referred to as an enhanced first order shear deformation theory, which is obtained via the mixed variational theorem with transverse normal deformation effect(EFSDTM_TN). The EFSDTM_TN has the same computational advantage as the FSDT_TN(FSDT with transverse normal deformation effect) does, which allows us to improve the through-the-thickness distributions of displacements and stresses via the recovery procedure. The thermal stresses obtained by the present theory are compared with those of the FSDT_TN and three-dimensional elasticity.

A Study on Piled Raft Constructed on Soft Ground through Numerical Analysis (수치해석을 통한 연약지반 상 시공된 Piled Raft 기초의 거동 연구)

  • Kim, Jeonghoon;Kim, Sunkon;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.3
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    • pp.29-34
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    • 2013
  • In this paper, numerical analyses were conducted on piled raft foundation settlement and pile bearing characteristics in soft ground. Results obviously showed longer and larger piles developed end bearing capacity values, but also showed the load of the central pile is larger than the surrounding piles in a group formation. Additionally, after pile yielding, the load carrying capacity exists as a raft. Moreover, results showed no transverse displacement according to embedment depth for the single pile case, but larger transverse displacements for deeper embedment depths.