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21.
A three‐dimensional displacement approach for analysis of laterally loaded piles in nonhomogeneous soil 
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下载免费PDF全文 Hiroyoshi Hirai 《国际地质力学数值与分析法杂志》2017,41(16):1605-1635
An analytical approach using the three‐dimensional displacement of a soil is investigated to provide analytical solutions of the horizontal response of a circular pile subjected to lateral loads in nonhomogeneous soil. The rocking stiffness coefficient of the pile shaft in homogeneous soil is derived from the analytical solution taking into account the three‐dimensional displacement represented in terms of scalar potentials in the elastic three‐dimensional analysis. The lateral stiffness coefficient of the pile shaft in nonhomogeneous soil is derived from the rocking stiffness coefficient taking into account the rocking rotation of a rigid pile shaft. The relationship between horizontal displacement, rotation, moment, and shear force of a pile subjected to horizontal loads in nonhomogeneous soil is obtainable in the form of the recurrence equation. The formulation of the lateral displacement and rotation of the pile base subjected to lateral loads in nonhomogeneous soils is presented by taking into account Mindlin's equation and the equivalent thickness for soil layers in the equivalent elastic method. There is little difference between lateral, rocking, and couple stiffness coefficients each obtained from both the two‐dimensional and three‐dimensional methods except for the case of Poisson's ratio near 0.5. The comparison of results calculated by the current method for a pile subjected to lateral loads in homogeneous and nonhomogeneous soils has shown good agreement with those obtained from analytical and numerical methods. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
22.
In analyses of compositional data, it is important to select a suitable unchanging component as a reference to detect the
behavior of a single variable in isolation. This paper introduces two tests for detecting the unchanging component, based
on a new approach that utilizes the coefficient of variation of component ratios. That is, the coefficient of variation of
a compositional ratio is subject to change when the unchanging component is switched between the denominator and numerator,
and the coefficient of variation tends to be small when the unchanging component occurs as the denominator against any arbitrary
components (Test 1). In addition, the ratio of the component pair that gives the lowest coefficient of variation is most likely
to represent the two unchanging components (Test 2). However, Tests 1 and 2 are not necessary and sufficient conditions for
uniquely finding the unchanging component. To verify the effectiveness of the tests, 500 artificial datasets were analyzed
and the results suggest that the tests are able to identify the unchanging component, although Test 1 underperforms when the
dataset includes a component with skewness greater than 0.5, and Test 2 fails when the dataset includes components with a
correlation coefficient greater than 0.75. These defects can be overcome by interpreting the two test results in a complementary
manner. The proposed tests provide powerful yet simple criteria for identifying the unchanging component in compositional
data; however, the reliability of this approach needs to be assessed in further studies. 相似文献
23.
Shigeko Togashi Teruo Shirahase Shiro Tamanyu 《Journal of Volcanology and Geothermal Research》1985,24(3-4)
The volcanic rocks from the Hachimantai geothermal area, Northeast Japan, are divided into the following five groups: (1) rhyolite of the Tamagawa Welded Tuffs (about 500 km3, 2.0–1.4 Ma); (2) andesite related to the Tamagawa Welded Tuffs (about 10 km3, 1.5 Ma); (3) andesite of the Matsukawa Andesite (about 100 km3, 1.8-1.2 Ma); (4) dacite of the Kashinai Formation (about 100 km3, 1.1 Ma); and (5) andesite of the Young Volcanics (about 300 km3, younger than 1 Ma).
ratios of less-altered samples of the five groups range from 0.7038 to 0.7046. There is no significant difference in ratios among the five groups in spite of differences in age and chemical composition. Therefore, fusion of or contamination by old acidic crust can be ruled out for the genesis of the voluminous acidic magma which produced the rhyolite of the Tamagawa Welded Tuffs and the dacite of the Kashinai Formation.The low
ratios and the chemistry suggest two possibilities for the genesis of the acidic rocks. One is a low degree of partial melting of the basic crust, which has a low
ratio, under high temperature. Another is a high degree of fractional crystallization from basic magma derived from the mantle. 相似文献
24.
Further Characterisation of the 91500 Zircon Crystal 总被引：28，自引：2，他引：28
Michael Wiedenbeck John M. Hanchar William H. Peck Paul Sylvester John Valley Martin Whitehouse reas Kronz Yuichi Morishita Lutz Nasdala J. Fiebig I. Franchi J.-P. Girard R.C. Greenwood R. Hinton N. Kita P.R.D. Mason M. Norman M. Ogasawara P.M. Piccoli D. Rhede H. Satoh B. Schulz-Dobrick O. Skår MJ. Spicuzza K. Terada A. Tindle S. Togashi T. Vennemann Q. Xie Y.-F. Zheng 《Geostandards and Geoanalytical Research》2004,28(1):9-39
This paper reports the results from a second characterisation of the 91500 zircon, including data from electron probe microanalysis, laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS), secondary ion mass spectrometry (SIMS) and laser fluorination analyses. The focus of this initiative was to establish the suitability of this large single zircon crystal for calibrating in situ analyses of the rare earth elements and oxygen isotopes, as well as to provide working values for key geochemical systems. In addition to extensive testing of the chemical and structural homogeneity of this sample, the occurrence of banding in 91500 in both backscattered electron and cathodoluminescence images is described in detail. Blind intercomparison data reported by both LA-ICP-MS and SIMS laboratories indicate that only small systematic differences exist between the data sets provided by these two techniques. Furthermore, the use of NIST SRM 610 glass as the calibrant for SIMS analyses was found to introduce little or no systematic error into the results for zircon. Based on both laser fluorination and SIMS data, zircon 91500 seems to be very well suited for calibrating in situ oxygen isotopic analyses. 相似文献
25.
Hiroyoshi Hirai 《Marine Georesources & Geotechnology》2018,36(7):805-817
An investigation was made to present analytical solutions of cyclic response to suction caisson subjected to inclined cyclic loadings in clay using a three-dimensional displacement approach. A model representing the relationship between vertical load and vertical displacement and that between lateral load and lateral displacement along the skirt of suction caisson subjected to cyclic loadings is proposed for overconsolidated clay. For the effect of vertical load on cyclic load capacity of suction caisson, using the Mindlin solution in the case of a vertical point load, the vertical stress of soil under the base of suction caisson is presented. For the stress state of soil beneath the base of suction caisson subjected to cyclic loading, the Mohr–Coulomb failure line and critical state line are presented and the relationship between total stress, effective mean principal stress, stress difference, and pore-pressure is elucidated. The comparison of results predicted by the present method for a suction caisson subjected to cyclic loadings in clay has shown good agreement with those obtained from field tests. Cyclic behavior of clay up to failure is made clear from the relationship between cyclic tensile load, vertical and lateral displacements, and rotation and that between depth, vertical, and lateral pressures. 相似文献
26.
Hiroyoshi Hirai 《国际地质力学数值与分析法杂志》2008,32(5):523-557
The investigation of equivalent elastic method is made to predict settlements and stresses of multi‐layered grounds and improved grounds. Analytical models to represent the heterogeneous elastic properties of layers in vertical and horizontal directions for multi‐layered grounds and improved grounds are proposed in taking into account the equivalent elastic modulus and the equivalent thickness. By introducing the equivalent thickness derived from Terzaghi's formula of the vertical stress, the equivalent elastic method of using the equivalent elastic modulus and the equivalent thickness is applied to the formulations concerning immediate settlements and vertical stresses in multi‐layered grounds and improved grounds. Comparison is performed between rigorous solutions and simulations for immediate settlements and vertical stresses in multi‐layered grounds and improved grounds. It is found that the proposed method is able to describe properly the characteristics of distributions for settlements and vertical stresses in multi‐layered grounds and improved grounds. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
27.
Hiroyasu Ando Takeshi Noguchi Masao Nakagiri Akihiko Miyashita Yasumasa Yamashita Kyoji Nariai Hiroyoshi Tanabe 《Astrophysics and Space Science》1989,160(1-2):183-189
Two steps have been taken to decide at what place and altitude to set up the JNLT on Mauna Kea. First, the wind tunnel experiment has been made in collaboration with the Institute of Meteorology using the two models of summit area with the reduced scales of 1/1000 and 1/5000. This study tells us that the north-west cone is suitable for JNLT. Secondly, we have done the measurement of the microthermal activities in this area with a 30 m tower, which was continued for about 4 months in collaboration with the University of Hawaii. This experiment has given the mean vertical profile ofC
T
2
over 4 months and its scale height in the boundayr layer on our site. By use of these measurements, the contribution of the boundary layer to seeing is estimated. The behaviour ofC
T
2
under strong winds can be explained very well by topographic effects, which is in fairly good agreement with the results of our wind tunnel experiment.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988. 相似文献
28.
A nonlinear numerical model has been formulated to study the propagation of a monochromatic surface wave. The model is formulated through the vertical integration of the continuity equation and the equations of motion. This model is investigated for wave propagation, velocity distribution, energy propagation and varying Courant, Friedrichs and Lewy's (CFL) condition. The applicability of this model for both shallow- and deep-water wave is also examined. The results and analyses are shown in details. The results obtained from the model are compared with the Stokes third-order wave theory and with the relevant experimental data. 相似文献
29.
Natural and wave-induced oscillations in Nagasaki Bay, a coupled bay—river system, are numerically studied. Formulation of the problem is based on the mild slope wave equation with modeled dissipation. Computations are performed by the finite element method originated from the classical variational principle. The numerical results show that the bay at the mean tidal level has natural modes of periods of 30.60 minutes, 17.28 minutes, 10.08 minutes, 7.67 minutes, etc. The 30.60-minute mode of the bay is characterized by a monotonic increase of the amplitude of oscillation from the bay entrance to the Urakami River mouth, whereas the 17.28-minute mode and the 10.08-minute mode attain maximum near Fukahori. It is also demonstrated that the 30.60-minute mode, the 17.28-minute mode and the 10.08-minute mode can be most severely resonated when the bay is subjected to oscillations in the open sea with periods of about 33.2 minutes, 17.9 minutes, and 10.1 minutes, respectively. The existence of the Urakami River seems to have an effect on mitigating the resonant bay oscillations, particularly if the relevant mode is of relatively low frequency and maximizes near the river mouth. 相似文献
30.
The present study describes a procedure for quantitatively analyzing satellite telemetry data to identify interspecific land use differences among four threatened crane species. The inherent inaccuracy of satellite telemetry data points, the temporal autocorrelation of those points, and the resolution of two land‐cover imagery products from the IGBP‐DISCover Global Land‐Cover Characterization Project (derived from AVHRR data) were assessed and integrated in a GIS. Satellite telemetry is a system where animals are tracked using battery‐operated transmitters and locations are calculated using triangulation from satellites. Using the variable spatial inaccuracy of the telemetry locations, each point was buffered using a radius based on the accuracy of the point, and then intersected with the land cover imagery. The research concluded that the methodology is valuable for studies of birds at a regional scale, with interspecific differences clearly evident, but that diurnal and nocturnal differences were not discernable due to the coarse resolution of both satellite telemetry and land‐cover data. 相似文献