Pipe–soil interaction for segmented buried pipelines subjected to dip faults          下载免费PDF全文

Mohammad Hossein Erami  Masakatsu Miyajima  Shogo Kaneko  Toshio Toshima  Shozo Kishi 《地震工程与结构动力学》2015,44(3):403-417

This paper describes an investigation of pipe–soil interaction equations suggested by currently used pipeline seismic design codes and the applicability of these equations to segmented pipelines. The results of computer‐aided analyses were compared to results obtained in full‐scale experiments on a segmented ductile iron pipeline 93 mm in diameter and 15 m in length. The pipeline was installed 600 mm below the ground surface in a sandy soil compacted to two different subgrade reaction values. The type of fault considered was a reverse fault with an intersection angle of 60° with the pipeline, and the fault movement was a total of 350 mm in three same steps in the fault trace direction. The findings of this study demonstrate the necessity of considering the nature of soil behavior in pipe–soil interaction equations and the effects of connection joints on the integrated response of pipelines to fault‐induced ground deformations. A new combination of equations constituting a direction‐wise selection from among the equations proposed by currently used guidelines is introduced as a new series to describe pipe–soil interaction for segmented pipelines and is verified using the results of full‐scale experiments. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

East Asian summer monsoon simulation by a 20-km mesh AGCM   总被引：1，自引：0，他引：1  

Akio Kitoh  Shoji Kusunoki 《Climate Dynamics》2008,31(4):389-401

East Asian summer monsoon climate simulated by a global 20-km mesh atmospheric general circulation model (AGCM) forced by the global sea surface temperature during the period 1979–1998 is investigated. In comparison with a lower resolution (180-km mesh) model experiment, it is revealed that the 20-km mesh AGCM shows the superiority in simulating orographic rainfall not only its location but also its amount. The Baiu frontal structure is also better simulated in the higher resolution model, which leads to stronger Baiu rainfall. The 20-km model also shows more intense extremes in precipitation. Interannual variability of June–August mean precipitation and seasonal march of the monsoon rain band are also investigated. This paper is a contribution to the AMIP-CMIP Diagnostic Sub-project on General Circulation Model Simulation of the East Asian Climate, coordinated by W.-C. Wang.  相似文献   

A fast topographic characterization of seismic station locations in Iran through integrated use of digital elevation models and GIS     

Sadra Karimzadeh  Masakatsu Miyajima  Batoul Kamel  Vera Pessina 《Journal of Seismology》2015,19(4):949-967

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Preliminary investigation of some large landslides triggered by the 2008 Wenchuan earthquake, Sichuan Province, China   总被引：14，自引：5，他引：9  

Fawu Wang  Qiangong Cheng  Lynn Highland  Masakatsu Miyajima  Huabin Wang  Changgen Yan 《Landslides》2009,6(1):47-54

The M _s 8.0 Wenchuan earthquake or “Great Sichuan Earthquake” occurred at 14:28 p.m. local time on 12 May 2008 in Sichuan Province, China. Damage by earthquake-induced landslides was an important part of the total earthquake damage. This report presents preliminary observations on the Hongyan Resort slide located southwest of the main epicenter, shallow mountain surface failures in Xuankou village of Yingxiu Town, the Jiufengchun slide near Longmenshan Town, the Hongsong Hydro-power Station slide near Hongbai Town, the Xiaojiaqiao slide in Chaping Town, two landslides in Beichuan County-town which destroyed a large part of the town, and the Donghekou and Shibangou slides in Qingchuan County which formed the second biggest landslide lake formed in this earthquake. The influences of seismic, topographic, geologic, and hydro-geologic conditions are discussed.  相似文献   

Determination of Lithium Contents in Silicates by Isotope Dilution ICP-MS and its Evaluation by Isotope Dilution Thermal Ionisation Mass Spectrometry   总被引：2，自引：0，他引：2  

Takuya Moriguti  Akio Makishima  Eizo Nakamura 《Geostandards and Geoanalytical Research》2004,28(3):371-382

A precise and simple method for the determination of lithium concentrations in small amounts of silicate sample was developed by applying isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS). Samples plus a Li spike were digested with HF-HClO₄, dried and diluted with HNO₃, and measured by ICP-MS. No matrix effects were observed for ⁷Li/⁶Li in rock solutions with a dilution factor (DF) of 97 at an ICP power of 1.7 kW. By this method, the determination of 0.5 μg g^-1 Li in a silicate sample of 1 mg can be made with a blank correction of < 1%. Lithium contents of ultrabasic to acidic silicate reference materials (JP-1, JB-2, JB-3, JA-1, JA-2, JA-3, JR-1 and JR-2 from the Geological Survey of Japan, and PCC-1 from the US Geological Survey) and chondrites (three different Allende and one Murchison sample) of 8 to 81 mg were determined. The relative standard deviation (RSD) was typically < 1.7%. Lithium contents of these samples were further determined by isotope dilution-thermal ionisation mass spectrometry (ID-TIMS). The relative differences between ID-ICP-MS and ID-TIMS were typically < 2%, indicating the high accuracy of ID-ICP-MS developed in this study.  相似文献   

Change in seismic activity in the Tokai region related to weakening and strengthening of the interplate coupling     

Akio Yoshida  Kohji Hososno  Toshimitsu Tsukakoshi  Akio Kobayashi  Hiromi Takayama  Stefan Wiemer 《Tectonophysics》2006,417(1-2):17

We investigate the relationship between changes in seismicity and crustal deformations in the Tokai region. We describe how seismicity in the subducted slab increased remarkably in the fall of 2000 and decreased in the fall of 2001, while in contrast, the crust seismicity decreased in the fall of 2000 and increased in the fall of 2001. We note that the trend of horizontal displacement at GPS stations changed coincidentally and we propose interpreting the increase and decrease in seismic activities and the changes in crustal deformations in a unified way based on changes in the state of the interplate coupling, i.e., the back-slip rate was reduced in the fall of 2000 and was partially restored in the fall of 2001. We explain why reduction of the back-slip rate increases seismogenic stress in the slab and decreases stress in the crust. We also describe the substantial positive dilatation observed in the region around Mt. Fuji in the fall of 2000 and suggest that the remarkable increase of low-frequency earthquakes beneath Mt. Fuji in October 2000 may have been caused by deceleration of the converging motion of the Izu micro-plate with the Eurasian plate. The decrease of the subduction velocity of the Izu micro-plate on the Suruga Trough in late 2000 would also have contributed to weakening of the interplate coupling beneath the Tokai region, since reduction of the relative velocity between overriding and subducting plates produces the same effect on the plate interface as a diminishing back-slip rate. However, subduction of the Izu micro-plate on the Suruga Trough was accelerated in early 2003, which may have caused increases in both slab and crust seismicities in that period.  相似文献   

Variability of Indian monsoon-ENSO relationship in a 1000-year MRI-CGCM2.2 simulation     

Akio Kitoh 《Natural Hazards》2007,42(2):261-272

There is a close relationship between interannual variability of the Indian summer monsoon rainfall and the El Niño/Southern Oscillation (ENSO) (drought conditions over India accompany warm ENSO events and vice versa). However, recent observations suggest a weakening of this ENSO-monsoon relationship that may be linked to global warming. We report here an analysis of the ENSO-monsoon relationship within the framework of a 1000-year control simulation of the MRI-coupled general circulation model (GCM), MRI-CGCM2.2. An overall correlation between the June-July-August (JJA) Nino3.4 sea surface temperature and the JJA Indian monsoon rainfall is –0.39, with reasonable circulation characteristics associated with the modeled ENSO. The simulated ENSO-monsoon relationship reveals long-term variations, from –0.71 to +0.07, in moving 31-year windows. This modulation in the ENSO-monsoon relationship is associated with decadal variability of the climate system.  相似文献   

Paleolimnological investigation of recent acidity changes in Sawanoike Pond, Kyoto, Japan     

Shunnichi Yoshikawa  Shigeo Yamaguchi  Akio Hata 《Journal of Paleolimnology》2000,23(3):285-304

Sawanoike Pond, an artificial reservoir constructed ca. 150 yrs. ago, lies in an area geologically sensitive to acidification and contains water that is presently weakly acidic (pH 5.5; alkalinity 15 eq 1^-1). Sediments from a core obtained from the northern part and a core from the central part of the pond were analyzed for organic matter, total organic carbon, total nitrogen, natural and artificial radionuclides, pollen, diatoms, metals and spheroidal carbonaceous particles. A peaty silt layer at the bottom of the central core was replaced by a silt layer initially rich in humic substances, but became more mineral-rich near the surface. Although most of the dominant diatoms throughout the cores were acidophilous taxa, some acidobiontic species increased moderately in abundance after the middle 1960's. Diatom-inferred pH values for the northern core are relatively low before about 1930, then increase, reaching a maximum level between the 1930's and the late 1940's. They then decrease to the surface and reach minimum level during the middle 1980's. Diatom-inferred pH declined by 0.4-0.5 units in the northern core and 0.2-0.3 units in the central core since ca. 1910, when vegetation around the shore changed to a community similar to that of recent years. An increase in labile Pb, Zn, Cd and spheroidal carbonaceous particles, indicative of atmospheric deposition of fossil fuel combustion by-products, preceded the decline in inferred pH. The inferred pH decline of the pond could be an acidification due to acidic precipitation caused by fossil fuel combustion.  相似文献   

Topographic characterization of seismic networks using topographic position index and Voronoi tiles: a case of the Hokuriku region,Japan     

Sadra Karimzadeh  Masakatsu Miyajima  Toshikazu Ikemoto 《Arabian Journal of Geosciences》2018,11(5):99

Usually, seismic record stations are established in various topographic slope positions, from valleys to ridges. In most previous studies, topographic amplification factor (TAF) is proposed as one of the indicators of earthquake wave amplification which can lead to overestimation of earthquake magnitudes in seismic networks. This paper uses an indicator called the “Topographic Position Index” for topographic characterization of seismic stations in the Hokuriku region, Japan, and deals with a seismic individuation method through Voronoi tessellation, which is a spatial approach, to propose suitable sites for topographically unbiased or less-biased seismic stations.  相似文献   

Experimental study on countermeasure against liquefaction-induced flotation of manhole using recycled materials packed in sandbags     

Masaho Yoshida  Masaru Tonoo  Masakatsu Miyajima  Masaru Kitaura 《世界地质(英文版)》2006,9(2)

The 2004 Niigata-ken Chuetsu earthquake in Japan caused serious damage to sewage facilities such as uplift of manholes and settlement of pavement above backfill soil for pipes. This paper deals with shake table tests in a 1 g gravity field on application of recycled materials for ground improvement to mitigation of liquefaction-induced flotation of manhole during earthquakes. The recycled materials used in tests were tire chips made of waste tires and crushed gravels made of waste reinforced concrete, and they were packed in sandbags. From the test results, it was confirmed that the recycled materials packed in sandbags could be treated as one of the countermeasures to restrain the flotation of manholes and settlement of ground surrounded by sandbags.  相似文献