土木学会論文集
Online ISSN : 1882-7187
Print ISSN : 0289-7806
ISSN-L : 0289-7806
1988 巻, 398 号
選択された号の論文の46件中1~46を表示しています
  • 川島 一彦
    1988 年 1988 巻 398 号 p. 1-12
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
  • 構造工学委員会 構造力学小委員会 離散化解析分科会
    1988 年 1988 巻 398 号 p. 13-20
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
  • Taweep CHAISOMPHOB, 長谷川 彰夫, 西野 文雄
    1988 年 1988 巻 398 号 p. 21-29
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    An ultimate strength analysis of the steel towers of the long-span suspension bridges is presented within the framework of an inelastic finite displacement theory of planar and spatial structures. The combined tower-cable system is employed to study the nonlinear effect of cables on the behaviour of huge towers. The Akashi-Kaikyo Bridge now under the first stage of construction for its seabed is selected in this study for investigations of ultimate strength behaviour of its steel towers subjected to the vertical dead and live loads. The current design practice of the Akashi towers is examined based on the present numerical results.
  • 三木 千壽, 坂野 昌弘, 村越 潤
    1988 年 1988 巻 398 号 p. 31-39
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Fatigue design curves of steel highway bridges were analyzed parametrically under computer simulated variable amplitude stresses. Crack propagation life of 4 types of welded joints was estimated by applying the constant amplitude da/dNK relationship and the liner cumulative damage rule. The configuration of fatigue life curves under variable amplitude stresses varied with the traffic constitution and the beam span particularly in the longer life region. The fatigue limit under variable amplitude stresses for each joint could be defined by using estimated fatigue life curves and Miner's rule.
  • Jae-Chul SHIN, Hyo-Nam CHO, Dong-Il CHANG
    1988 年 1988 巻 398 号 p. 41-50
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This study is directed for the evolution of rational approaches to the systematic evaluation of the load carrying capacity of bridges based on the practical and advanced second moment reliability methods. Raliability-based rating criteria in the form of load and resistance factor rating (LRFR) code are presented in order to show the direction of the development of rating codes. Furthermore, an approach using the reliability index as a measure of rating of an existing bridge is suggested.
  • 志村 正幸, 川原 睦人
    1988 年 1988 巻 398 号 p. 51-59
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    In this paper, a finite element method based on the velocity correction method is presented. However there arise difficulties about the boundary conditions which have been used for the solution of the pressure Poisson equation. For example, in the calculations of the conventional analysis, uniform pressure (P=O) or normal gradient of pressure equal to zero (∂P/∂n=0) has been adopted especially on the open boundary which is artificially introduced as the limitation of the calculation domain for the sake of analysis convenience. However, these boundary conditions are false because the pressure on the boundary can not be prescribed in general for the time-dependent problems. In order to improve these boundary conditions, a new approximation method is proposed in which the boundary pressure Poisson equation is solved for each time step.
    The method presented in this paper employes the linear interpolation functions based on the quardrilateral isoparametric elements.
  • 中村 俊一, T. A. WYATT
    1988 年 1988 巻 398 号 p. 61-69
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Cable-stayed bridges with multi-stays have been recently planned and constructed in many countries probably because of aesthetic and economical superiority. It would be generally possible that the girder could become much slender by properly controlled cable prestresses. The system has been designed in this paper by mainly BS 5400, one of the few codes which have introduced the limit states design. The consistently optimised designs have been achieved by Linear Programming in order to compare the various bridge configuration. A simple method has been proposed to estimate the buckling capacity of the girder. The girder stiffness obtained is substantially lower than that of existing bridges. The bridge with multi-cables could have much slender girders than that with few-cables.
  • 大津 政康
    1988 年 1988 巻 398 号 p. 71-79
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Based on a generalized theory of acoustic emission which we previously proposed, an inverse procedure for the source characterization of AE is discussed. To determine the source kinematics (crack type and crack orientation), a moment tensor representation is introduced. It is clarified that the eigenvalue analysis of the moment tensor can afford essential information on the kinematics of crack movement. Then, an deconvolution analysis provides the kinetics of crack motion as a source-time function. To confirm the applicability of the source inversion procedure, numerical experiments are performed on the surface observation of AE. By employing simulated AE waveforms, source characteristics are inversely solved and determined. Results demonstrate a great promise of the proposed procedure for the source characterization of AE.
  • 川谷 充郎, 小松 定夫
    1988 年 1988 巻 398 号 p. 81-88
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Taking account of the roughness of roadway surface, the authors have theoretically investigated nonstationary random responses of highway bridges to moving vehicles. On the basis of the assumption that a sequence of the surface roughness is a stationary random process, the simultaneous nonstationary random vibrations of both bridge and moving vehicles have been analysed by means of the theory of random vibration. It can be considered that the two-degree-of-freedom sprung-mass system with both front and rear axles is a more realistic model of each heavy dump truck than the one-degree-of-freedom system usually used. The effect of some important factors in the whole system on the root mean square of the random responses of highway bridges are discussed.
  • 奥村 勇
    1988 年 1988 巻 398 号 p. 89-98
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    A solution to a state of plane stress and a solution to a state of generalized plane stress of transversely isotropic, moderately thick plates in cylindrical coordinates are proposed. The solutions are derived from a generalized Elliott's solution which includes five potential functions. Expressions for components of displacement and stress in the solutions are presented in referring to non-axially symmetric problems of transversely isotropic, moderately thick circular or annular plates. As an application of the solutions, an axi-symmetric bending of a transversely isotropic, moderately thick circular plate subjected to a partial load is analyzed.
  • 山口 宏樹, 藤野 陽三
    1988 年 1988 巻 398 号 p. 99-107
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Effects of support flexibility on the modal damping of flexural oscillation of cables are examined in relation to the dynamic characteristics of cables. The modal damping is experimentally measured using elastically-supported cable model. Finite element method is employed in order to calculate natural frequencies, normal modes and additional dynamic strains. It is found that the flexibility of support has significant effects upon the modal damping of only symmetric modes in the region of modal transition. The experiment indicates that the energy dissipation from support is one of the major sources of damping and that this must be further studied.
  • 山崎 文雄, 篠塚 正宣
    1988 年 1988 巻 398 号 p. 109-119
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Probabilistic safety analysis methods for structural systems involving spatially variable material properties are studied. For the cases to which the first-order second-moment methods cannot be applied well, two different Monte Carlo methods are employed in conjunction with the finite element technique. “Monte Carlo simulation”, which is based on the stochastic field simulation technique and the safety judgment for each trial, is recommended because its accuracy is guaranteed irrespective of the number of random variables. On the contrary, the accuracy of “Monte Carlo integration”, where a numerical integration of the joint density function of the random variables is carried out by means of sample-mean Monte Carlo method, goes down dramatically as the number of random variables getting large. Numerical examples verify the above argument and reveal the effects of correlation parameters on the local and system limit state probabilities.
  • 由井 洋三, 廣瀬 進, 栗林 栄一
    1988 年 1988 巻 398 号 p. 121-128
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This paper presents the use of the past seismic data to predict seismic motion intensity for short duration. The factors that affect this predicted value are studied, and application to a selected site of the straits of Akashi is presented. The study using a areal source model with assumed seismicity in each divided zone showed that earthquake of relatively small magnitude in the site plays an important role for estimating expected seismic load of the site. For structures under construction, an attempt to estimate the expected value of restoration cost for a three-span suspension bridge by probabilistic approach is also presented.
  • 垂水 祐二, 伯野 元彦
    1988 年 1988 巻 398 号 p. 129-138
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Various liquefaction analyses have been made. No numerical liquefaction analysis in which sand is considered a non-continuous material, however, has yet been reported. In 1971, the Distinct Element Method (DEM) was introduced by Cundall. This method is a numerical simulation by which rock behavior is analyzed based on the assumption that individual rock elements satisfy the equation of motion. We developed a modified DEM that takes into account pore water pressure based on Darcy's law. We analyzed the liquefaction of saturated sand under seismic excitation. Excessive pore water pressure in the numerical results rose gradually due to the effect of shaking. This result agrees with results of past laboratory tests.
  • 川島 一彦, 小山 達彦
    1988 年 1988 巻 398 号 p. 139-146
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    A series of dynamic loading tests with use of large-scale reinforced concrete bridge piers were conducted to investigate an effect of loading hysteresis under displacement control load reversal tests. The specimens were subjected to three loading hysteresis which idealized sequence of loading displacement developed during earthquakes, i. e., in Type 1 loading, displacement was monotonically increased with increasing number of load reversals, and Type 2 used a hysteresis in the reversal order of the Type 1. Type 3 loading used a combination of Type 1 and Type 2 loading.
    It was understood from the study that energy dissipation capabilities depend on the loading hysteresis. First large displacement progresses deterioration of energy absorbing capability. It was also found that skelton curve of the hysteresis loop shows significant differences in accordance with loading path.
  • 飯田 昌弘
    1988 年 1988 巻 398 号 p. 147-155
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The ability of Japanese strong-motion arrays for inferring earthquake source processes is investigated using a source inversion method previously developed on the basis of the Wolberg's prediction analysis. The ability of the whole array and the contribution of individual array stations are estimated for three array networks existing in Japan. They are for the 1984 Naganoken-seibu earthquake, the 1978 Miyagiken-oki earthquake, and the anticipated Tokai earthquake.
    The results indicate that two different kinds of stations are simultaneously required to infer detailed source processes. One is near-source stations, and the other is stations surrounding the earthquake fault with good azimuthal coverage.
  • 山田 善一, 河野 健二, 家村 浩和, K. VENKATARAMANA
    1988 年 1988 巻 398 号 p. 157-166
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Dynamic response of offshore structures to random sea waves and strong earthquake motions is investigated. Sea waves are modelled by Bretschneider's wave energy spectrum and ground motions are represented by Kanai's power spectrum. Governing equation of motion is obtained by the substructure method. Response analysis is carried out using frequency-domain random vibration approach. Wave responses are found to be generally larger whereas seismic responses are smaller when soil-structure interaction effects are considered. Reliability studies show that earthquake loadings provide comparable results to those of wave loadings, but the latter have more significant effects on response evaluations because of the longer duration time.
  • 杉山 俊幸, 藤野 陽三
    1988 年 1988 巻 398 号 p. 167-175
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The optimal allocation of safety factors is discussed for long-span suspension bridge. Not only statistical uncertainties but also uncertainties due to unknown factors or gross errors such as human errors are taken into account. The optimal allocation of the safety factors for cables and girder in suspension bridge has been obtained by the simple reliability optimization of structural system. The results suggest to increase the safety factor of girders for wind load and to decrease the safety factor of cables for dead load. The current code appears to be not balanced and revision is suggested.
  • 藤野 陽三, Benito M. PACHECO, Piyawat CHAISERI, 孫 利民
    1988 年 1988 巻 398 号 p. 177-187
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    A new kind of damper, Tuned Liquid Damper (TLD) relying on motion of shallow liquid in a rigid cylinder, is experimentally studied. Prototype-sized circular containers with diameters 40cm and 60cm and partially filled with water, are attached to a single-degree-of-freedom structural model with natural period of 2sec. The damper effect is measured in terms of the increase in the logarithmic rate of decrement of free oscillation of the main structure. The structural displacements range from 8cm down to 0.25cm. It is seen that, for large damping effect at small amplitude of structural vibration, it is necessary to tune the fundamental sloshing period of the liquid to the natural period of structure; hence the name Tuned Liquid Damper. Breaking of surface waves, which is dependent on structural vibration amplitude, appears to be a major mechanism of energy dissipation in the range of displacements considered. Also investigated are the effects of: ratio of liquid frequency to structure frequency; liquid viscosity; container bottom roughness; container roof height; ratio of liquid mass to structure mass; and container diameter.
  • 竹名 興英, 伊藤 文夫, 西野 文雄, 三木 千寿
    1988 年 1988 巻 398 号 p. 189-192
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    It is said that fatigue strength decreases according as thickness increases. In the Honshu-Shikoku Bridges, a material which is by far thicker than the one for former bridges is used. The effect of thickness of main plate and diaphragm was analyzed by the fracture mechanics method. The results of this reseach were used for fatigue design of the Honshu-Shikoku Bridges.
  • Phoonsak PHEINSUSOM, 藤野 陽三
    1988 年 1988 巻 398 号 p. 193-196
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Effect of turbulent wind on modal interaction in galloping of structure with two closely-spaced natural frequencies is studied. Numerical simulation indicates that the presence of certain intensity of turbulence causes the modal interaction, i. e. the dominant vibration mode alternately changes from one mode to the other in time domain. The modal responses seemingly are the combination of galloping response with time-varying amplitude and the random buffeting responses. This is also confirmed by wind tunnel observations.
  • 宇佐美 勉, 寺尾 圭史
    1988 年 1988 巻 398 号 p. 197-206
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    A numerical study is presented on the strength of unbraced steel framed structures with local buckling. A finite element program has been developed to trace up to collapse the inelastic behavior of steel framed structures by using moment-thrust-curvature curves of locally buckled stub-columns computed by the authors. The numerical results are compared with the design formulas considering the decrease in the strength due to local buckling. An examination is also made on the influence of the modifications of the effective length factor K and the equivalent moment ratio Cm. As a result, a better design formula has been obtained.
  • 阿部 和久
    1988 年 1988 巻 398 号 p. 207-216
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The author consider the accuracy of boundary element solutions in the neighborhood of a boundary in two dimensional elastic problems. A solution of boundary element method requires integrations on the boundary. It is known that a solution which is evaluated by numerical integration reduces the accuracy in the neighborhood of the boundary. This is by the reason that the integrand shows singurality on the boundary near the internal observation point. A method is presented for the estimation of the error on Gauss quatrature. By this method it is made sure that errors with displacements and stresses are to be expressed in simple forms. And it is possible to prognosticate the range in which the solution be incorrect. Application is made to evaluate stresses on the surface.
  • 林 正, 坂田 敦, 西谷 雅弘
    1988 年 1988 巻 398 号 p. 217-225
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Finite strip method has not been used for the analysis of structures having irregular geometry and its applications are considerably restricted. Then, sub-parametric strip elements are presented on the bending analysis of thin plates in arbitrary shape. In the formulation of the strips, the following techniques are adopted: the element shape is defined by nodal coordinates and the mapping procedure used in the ordinary finite element approach; the parent elements of the strips are thick strips having an internal nodal line and a bubble mode; the series used in the displacement functions are given by polynomials instead of the commonly used eigenfunctions; and the sub-parametric strips are formulated by the help of the discrete Kirchhoff constraint conditions and a procedure of condensation. Finally, the versatility and accuracy are illustrated through several numerical examples.
  • 大久保 禎二, 藤脇 敏夫
    1988 年 1988 巻 398 号 p. 227-236
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    A new analysis method for straight and continuous beam structures with nonlinear materials is proposed on the basis of the principle of minimum complementary energy and mathematical programming algorithm.
    The bending moment distribution of a continuous beam structure is expressed in terms of the unknown redundant bending moments acting at the supports and the analysis problem is formulated as an unconstrained total complementary energy minimization problem, Then the redundant bending moments are determined by solving the energy minimization problem with the aid of a sequential quadratic approximation algorithm. In the process of the energy minimization, pre-arranged bending moment-complementary energy relations for the cross-sections of beam elements made of given nonlinear materials are used very effectively for calculations of the total complementary energy and the sensitivities of beam structure.
    The problem formulation and analysis algorithm of the proposed method are quite simple and applicable for any types of linear and nonlinear material beam problems. The reliability and efficiency of the method are confirmed by comparing the results obtained with those by the finite element method for several statically indeterminate continuous beams with linear and three types of nonlinear materials.
  • 佐藤 泰生, 佐藤 吉彦, 三浦 重
    1988 年 1988 巻 398 号 p. 237-244
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The guard rail existing in railway turnout receives a large lateral guiding force from running wheels. This force is one of the important factors limiting the running speed of trains at turnouts. The paper describes: (1) The results of a series of running tests on Kosei line, which clarify the actual condition inducing the force; (2) A theoretical study performed by a simulation method using a dynamic rolling stock model; and (3) The countermeasures to suppress the force at the guard rail.
  • 園田 恵一郎, 沖野 真, 林 秀侃, 喜田 浩
    1988 年 1988 巻 398 号 p. 245-254
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Epoxy bonded Steel Plate Method is a reinforcement method for repairing cracked and damaged RC slabs of bridge. In the method, a steel skin plate is adhered to the bottom surface of damaged concrete slab with epoxy resin.
    The aim of this paper is to examine the reliability of this method. Model slabs were tested under the repetition of truck wheel loading in both the states before and after repairs. From various observations on deflection-growth, cracking in concrete, and strain-increase in steel bar and skin plate, it is concluded that the method is fairly reliable even if the repair is done at the stage of so severe damage as to cause diagonal tension (shear) cracks in the concrete section of slab.
  • 吉浪 康行, 大村 裕
    1988 年 1988 巻 398 号 p. 255-264
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Ultimate compressive strength and welding residual stress of high-tension steel stiffened plate was investigated experimentally by comparing with mild steel stiffened plate. As for residual compressive stress which was considered to have important effect on the ultimate compressive strength, residual stress in high-tension steel was less 0.10-0.15 σy than that in mild steel. From this difference, ultimate compressive strength of hightension steel should be expected to be higher than that of mild steel theoretically, but 12 test results of ultimate compressive strength showed no clear advantage of hightension steel. From these experimental results, this positive factor of residual stress should be considered to have not so much important effect on the ultimate strength.
  • 坂井 藤一, 磯江 暁, 平川 長, 面谷 幸男
    1988 年 1988 巻 398 号 p. 265-273
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    In 1985 the authors carried out a series of static tilt tests with a very big tank model in order to study the aseismic safety of large-scaled cylindrical liquid storage tanks. The model has about 10 meter diameter and 8 meter height and is made of aluminum alloy, satisfying the similitude requirements to actual large-scaled LNG, LPG and oil tanks. Prior to the static tilt tests, several cases of water-filling test of the model tank were conducted. It is very important from the point of view of tank design to grasp the tank behaviors in these conditions correctly. This paper is dealing with the water-filling behaviors of the tank which has not been clarified so far. The behaviors are discussed in relation with the initial deflections of tank shell and base plate and from comparison with the finite element analysis.
  • 星谷 勝, 永田 茂
    1988 年 1988 巻 398 号 p. 275-284
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This paper proposes an effective method for evaluating system failure probability for plane frame structures in which loads and material strength as well as geometrical properties are random variables. This method makes possible easy calculation of system failure probability for large structures by integrating the concept of the probabilistic network evaluation technique (PNET method) into identification procedure of stochastically dominant failure modes. Then, numerical examples of plane frame structures are demonstrated to show the effectiveness of the proposed method.
  • 久保 雅邦, 亀田 弘行
    1988 年 1988 巻 398 号 p. 285-294
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Probabilistic analysis of live load for highway bridges is made by applying vehicle load models measured on an urban expressway. In the analysis, the probability distribution of lifetime maximum response is estimated numerically by convolution integral based on combination of target vehicle on viewed point and train of congested vehicles. Additionally, the stochastic properties of live load are examined theoretically by using truncated exponential distributions for each vehicle load, and results show that upper bounds of vehicle loads especially of large size trucks and trailers are dominant to the lifetime maximum response and that the extrapolating mutiplication of powered probability distribution can not be sufficiently applied to estimate it.
  • 上杉 真平, 大津 政康
    1988 年 1988 巻 398 号 p. 295-301
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    As a numerical technique, the Finite Element Method (FEM) is versatile for evaluating problems with complex geometries and materials. It is, however, not efficiently applicable to problems of wave scattering in an infinite domain. The Boundary Element Method (BEM) has been used very effectively in elastic wave problems with a homogeneous infinite domain. Therefore, it is reasonable to couple the FEM with the BEM in order to provide a single methodology for analyzing problems including non-homogeneous materials in an infinite domain. In the present paper, a method to couple a BEM domain with a FEM domain is proposed on the basis of the variational principle. To demonstrate the usefulness of the proposed method, P, SV and SH wave fields were investigated. From the results, applicability of the proposed method is discussed.
  • 川谷 充郎, 嶋田 玲志
    1988 年 1988 巻 398 号 p. 303-309
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Dynamic responses of highway bridges to moving vehicles are taken into consideration of impact, that is, multiplying static live load by impact coefficient in design codes of bridges. Recently, the effect of road surface roughness on the dynamic response of bridges to moving loads has been paid attention by researchers. The nonstationary random response of bridges to a series of loads is analyzed by means of the theory of random vibration, taking account of the road surface roughness. The effects of natural frequency of bridges and headway between vehicles on the root mean square of random responses of simple girder bridges and continuous ones are discussed. Impact coefficients of girder bridges are proposed on the basis of the analytical results.
  • 西村 宣男, 吉田 信博
    1988 年 1988 巻 398 号 p. 311-318
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The coupled buckling behaviors of steel H-section columns are investigated by the FEM analysis including both geometrical and material nonlinearities. The FEM model is consisted of two regions, one is plated assembly to evaluate the local plate deformation and another is the beam element substructure. It is made clear that the reduction from the column strength or the local buckling strength caused by the coupling effect is affected by the cross-sectional profile. And a design formula for the coupled buckling strength that contains the cross-sectional parameter is presented. The accuracy of the formula is examined by the comparison with the experimental data and the theoretical results.
  • 志波 由紀夫, 川島 一彦, 大日方 尚巳, 加納 尚史
    1988 年 1988 巻 398 号 p. 319-327
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This paper presents a practical method to evaluate the longitudinal stiffness of shield tunnel linings which is of great importance in the seismic response analyses of shield tunnels. Linings of shield tunnels are constructed assembling a number of segments and joints, and have structural discontinuity in the longitudinal direction. In this paper, relationships between stress and deformation of segments-joints system, both for axial force and for bending moment, are formulated into the form of “equivalent stiffness”, i. e., the stiffness of uniform beam having the same stress-deformation relation as that of segments-joints system.
    Modeling the lining into a uniform beam with the equivalent stiffness, it makes possible to analyze behavior of shield tunnels by means of seismic deformation method as well as other pipe-like underground structures. Parameters which have influence on the equivalent stiffness are also discussed.
  • 榊 信昭, 長岡 弘明, 岡本 隆, 小山 和夫
    1988 年 1988 巻 398 号 p. 329-337
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This paper deals with the practical applicability of a calculation method which can be used to predict liquid-surface displacement during an earthquake. We took measurements of the sloshing of huge cylindrical tanks and then compared our calculated values with actual earthquake records. This calculation method is based on the linear potential theory. The earthquake records of LNG or petroleum storage tanks are used for the comparison. When the liquid-surface displacements are small, the calculated natural periods and liquid-surface displacements agree with the recorded figures. But as the liquid-surface displacements become larger, the recorded values become larger than the calculated ones by reason of a non-linear response. The recorded values become 0.84 to 1.12 times as large as the calculated ones.
  • 中村 晋, 末富 岩雄, 秋山 伸一, 吉田 望
    1988 年 1988 巻 398 号 p. 339-348
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Source mechanism and characteristics of the horizontally propagating waves generated around a dipping basement due to the incident SH wave are investigated. A new analitical method which combines boundary elements, finite elements and energy transmitting boundary is proposed. Two layered media, the upper layer of which has semi-infinite boundary in one side and a dipping interface in the other side, is used in the analysis. It is found that the incident SH wave is mostly transformed into Love wave whose period is close to Airy phase at the horizontal part of the surface layer in the case that both the ratio of wave impedance and the inclination of basement are small; all reflected SH wave is predominant in the other case.
  • 小坪 清真, 井嶋 克志, 後藤 茂夫
    1988 年 1988 巻 398 号 p. 349-357
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This paper presents effects of vibrations of transmission insulators on towers and lines subjected to earthquake. Free vibration analyses of transmission line and insulators are made by using the method of modal analysis, which adopts individual modes of a suspended line and suspended insulators. The theoretical results agree well with the experimental ones of dynamic tensions in a transmission line and insulators model excited by periodic longitudinal displacements at one end. Finally, as a result of seismic response calculations of towers, lines and insulators systems in two cases, it is shown that they are about equal or larger than the seismic responses of lines and towers considering the insulators as an added mass, but smaller than those of a single tower.
  • 桝田 秀芳, 翠川 三郎, 三木 千寿, 大町 達夫
    1988 年 1988 巻 398 号 p. 359-365
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    As earthquake preparedness is one of the indispensable factors for disaster mitigation, a questionnaire survey was made on consciousness of earthquake preparedness of junior high school students. The formative process of the consiousness consists of three steps; the first is motivation caused by disaster mitigation activities or impression of disastrous earthquakes, the second is accumulation of interest and knowledge induced by the motivation, and the third is the action for earthquake preparedness. Based on this formative process, a fuzzy reasoning procedure was applied to grading of consciousness of earthquake preparedness. By this procedure, effects of earthquake education could be evaluated quantitatively, and promotion of desirable education systems might be possible.
  • 榊 信昭, 鈴木 操, 長岡 弘明, 小山 和夫
    1988 年 1988 巻 398 号 p. 367-376
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The earthquake observation has been carried out on the large-scale in-ground LNG storage tank made of reinforced concrete. The strains of the side wall and the accelerations were recorded. The strain response characteristics investigated by the records and FEM analyses are as follows: (1) The circumferential component strain caused by the axial force is predominant in all earthquakes. (2) The circumferential distribution modes of the circumferential component strains are predominant in the following two modes, i. e., the axisymmetric mode or the sine mode which is caused by the ring deformation mode. (3) The SH body wave causes the sine mode. One of the earthquake ground motion components which causes the axisymmetric mode is the Rayleigh wave.
  • 山田 健太郎, 左高 茂樹
    1988 年 1988 巻 398 号 p. 377-384
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    Fatigue crack growth rates of SM50A, SM58, and HT80 steels in air and in 3% salt water were measured. Crack growth rates in salt water were 1 to 1.5 times faster than that in air, when subjected to loading speed of 1Hz. Bending fatigue tests were also carried out for non-load carrying fillet welded specimens. Fatigue cracks were initiated at weld toes and propagated in semi-elliptical shape. Fatigue life in salt water seemed to be about one quarter of that in air, despite of a few failed data in air. Fatigue crack propagation life of stiffener detail was estimated using fracture mechanics technique and the analytical results were in good agreement with the test data.
  • 本田 秀行, 小堀 為雄
    1988 年 1988 巻 398 号 p. 385-394
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    In this paper, the numerical data base (BINS) on roadway roughness of highway bridges is presented. The BINS is composed of the data bases (BINS 1 and BINS 2) of two kinds on longitudinal roughness and roughness of expansion joint point based on the roughness data measured by the authors. The BINS is supported by IBM computer 370/3090, and is made by EXEC I/O procedure using REXX language. IBM computer VM/SP above re-lease 4 is possible to use the system of the BINS.
    The applied examples of the BINS are presented to quantitatively investigate the characteristics of roadway roughness, and to give the technical data using the vibration problems of highway bridges under moving vehicles.
  • 深沢 誠, 大畦 久雄, 加藤 昌彦, 三木 千寿
    1988 年 1988 巻 398 号 p. 395-404
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This study summarized non-destructive methods and evaluates their reliability and adaptability for the detection of fatigue cracks in painted steel bridge members. On the painting, it was possible to detect small cracks up to 5mm length with oxide formation by visual examination. And cracks with length longer than 5mm were detected by the eddy current examination with the suitable coil and frequency of the current. However, these were poor in the estimation of crack length. A combination of these examination over the paint and the close examination after removing the paint would be a superior detection method. For the estimation of the crack length, the magnetic particle examination was found exellent, allowing the detection of cracks with length longer than 2mm with accuracy of better than 1mm provided the paint was removed.
  • 三上 市藏, 出口 恒宣
    1988 年 1988 巻 398 号 p. 405-408
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The energy method is used to analyze accurately the elastic buckling of the plate girder webs with the longitudinal and/or transverse stiffeners for shear loading. The requirements of the rigidity for the longitudinal and transverse stiffeners of plate girder subjected to shear are discussed.
  • 島田 忠幸, 西村 昭
    1988 年 1988 巻 398 号 p. 409-412
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    The estimating method of tension imposed on bridge cables by measuring their natural frequency, so-called vibration method, is very convenient on the construction site of structures with cables. However, there still exist several problems concerning the flexural rigidity of cables that have to be overcomed so as to get reliable and accurate estimation as follows:
    (1) The flexural rigidity of the cable is needed to be obtained beforehand, but few data have been reported in regard to the property.
    (2) The accuracy of estimated cable tension, affected by the flexural rigidity in particular, is necessary has to be analysed theoretically.
    (3) A simple method of estimating the flexural rigidity of cables on the construction site is desired.
    In this paper, the above mentioned problems are theoretically and experimentally studied.
  • 延藤 遵, 藤野 陽三, 伊藤 学
    1988 年 1988 巻 398 号 p. 413-416
    発行日: 1988/10/20
    公開日: 2010/08/24
    ジャーナル フリー
    This technical note presents an analytical and experimental study on the effectiveness of tuned mass damper (TMD) to suppress a wind-induced coupled flutter of bridge deck. In the analysis, Theodorsen's aerodynamic forces are assumed to act on a bridge deck model. Parametric calculations indicate that critical velocity of the coupled flutter can be increased appreciably by TMD. Wind tunnel test is also performed and confirmed the effectiveness of TMD.
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