2007, 29(1):3-11.
Abstract:Taking Lanzhou city as an example, the characteristics of groung motion parameter microzoning in cities which are located in the yellow river valley in northweastern China are studied. The importance of input data for calculating the parameter during strong earthquakes is demonstrated, the relationships between the ground motion parameter microzoning and the local cite conditions, the essences of soil layers, the geomorphological condition are analysed. According to the site conditions and calculating results the urban part of Lanzhou city is divided into 3 regions, and the parameters of each region for aseismic design are also illustrated.
YUAN?Zhong-xia , WANG?Lan-min , WANG?Jun
2007, 29(1):12-17,39.
Abstract:In this paper, the internals factors of loess water collapse are discussed from the microstructure point of view. Then, based on laboratory test, the most determinant factors on loess water collapse are found and the mechanism of water collapse of loess is revealed based on the known facts and theories. Through study from the two aspects, the problem of water collapse of loess and its nature are better explained.
LIU?Lu-bo , CHEN?Xiao-fei , WANG?Yan-bin
2007, 29(1):18-25.
Abstract:The pseudospectral methods, especial Fourier method and Chebyshev method are introduced first. Then the first order 2-D elastodynamic seismic wavefield equation based on velocity-stress by the Chebyshev pseudospectral method is solved, and in the compatation the Lame problem, the problem of demolition source in center of homogeneous media, the velocity anomaly intermedia, and the more important problem, headwave propagation in multi-layered media are simulated. At last, we try to get a similar pseudospectral method to Chebyshev method.
YANG?Yan , QI?Ji-lin , SONG?Chun?xia , LI?Ning
2007, 29(1):26-29.
Abstract:According to the recent advancements in quantitative study on soil structure, two sensitivities, of clay in conventional soil mechanics, stress sensitivity and strain sensitivity, are explicitly defined in this paper. Taking Xi'an loess as the study subject, both undisturbed and reconstituted saturated samples from different depths are prepared for 1-D consolidation testing. Through the trial calculations, two sensitivities are obtained from the e-logP coordinates which are have relatively stable changing tendency. Contrasting with the stress sensitivity, the strain sensitivity has obvious advantages from the points of view of calculation and changing tendency.
WANG?De-li , YONG?Yun-dong , HAN?Li-guo , LIAN?Yu-guang
2007, 29(1):30-34.
Abstract:When finite difference (FD) method is used in modeling the propagation of seismic wave in 3-D viscoelastic complex media, it consumes vast quantities of computational resources. So on single PC or workstation, 3-D calculations are still limited to small grid sizes and short seismic wave traveltimes. In this paper, the parallel FD algorithm which based on a message passing interface(MPI) is introduced to solve above problem properly. Using PCCluster we can calculate the wavefield of the large 3-D viscoelastic complex models, furthermore predict and understand the kinematic and dynamic properties of seismic waves propagating through the models of the crust. It helps us in every stage of a seismic investigation.
2007, 29(1):35-39.
Abstract:For the complexity and uncertainty of landslide system, the fuzzy synthetic judgment model of landslide stability assessment is set up using fuzzy mathematics method, which is composed of 5 aspects (lithology, geologic structure, landform, groundwater, and rainfall)in 2 levels with 9 factors. The grading standard of each factor, as well as the proportion, is put forward. As the examples, 6 main landslides along G212 highway in Longnan, Gansu province, are assessed. The results of assessment show that the worst one is at Qinyu, the next are Feng'anshan and Shi'ezi, and the relatively better ones are Qingshuizi, Gushuizi and Lubanya.
MAO?Yu-kun , LIU?Feng-yin , LI?Ning , QI?Chang-jun
2007, 29(1):40-44.
Abstract:The history and present situating of the cone penetration test (CPT) in China are introduced. Using different theories related to CPT the main factors affecting the penetration capability, and the dimitations and complexity of CPT in practice are analyzed. Meanwhile a new way is put forward to improve the capability of penetration, in order to solve the problems the CPT met in hard loess, frozen earth and soft rock areas in west part of China. By means of the lab test we take effort to establish the relationship of the parameters of the soils with the measured data from gyration penetration process.
XU?Hao-ming , WANG?Jia-ding , ZHANG?Yu-qing
2007, 29(1):45-48,57.
Abstract:Using survey grid method the structural plane in rocky slope alongside the Qingyuan-Lianzhou Highway in Guangdong province are measured. The survey parameters are counted and analyzed by thr "structural equator proiection data analysis package", and simulated by the 2-D network simulation program. Based on this works the characteristics and combination relationship of the structural planes, as well as their influence on the slopes’stability, are researched. The result shows that the influence of the combination relationship on the slopes" stability is obvious.
QIU?Ren-dong , SHI?Yu-cheng , XU?Shun-hua , HU?Ming-qing
2007, 29(1):49-53.
Abstract:Based on the characteristic of the grotto rock reinforced by prestress anchor cable, taking three typical engineering sections in Yulin grotto in Anxi county Gansu province, as exampies, the simultating computation for the displacement field and stress field of the grotto rock under seismic load is done using dynamic finite element method, the change regularity and dynamical response of the grotto rock are concluded. Meanwhile through analyzing the characteristic of the frequency spectrum of real seismic load, the influence of sismic load's feature period on dynamic response result of the grotto rock is revealed.
LIAO?Sheng-xiu , CHENG?Ju-hong
2007, 29(1):54-57.
Abstract:It’s possible that liquefaction and seismic collapse could occur during earthquake in high-humidity loess, which has been proved to be true both in laboratory dynamic test and investigation of paleo-earthquakes. At present, the code of engineering doesn't put the predictive judgment for the liquefaction of loess into consideration. In this paper, some cases of loess ground treatment are introduced, in which the treated saturated loess liquefied, thus the ground sank, caused by mechanical shaking or impact. It is meaningful to research on the liquefaction mechanization, liquefaction discrimination, harmfulness judgment and engineering precautionary measure for loess.
YUAN?Dao-yang , LEI?Zhong-sheng , GE?Wei-peng , LIU?Xing-wang , LIU?Bai-chi , ZHANG?Jun-ling
2007, 29(1):58-63.
Abstract:According to the textual analysis of historical references, the earthquake of west Gangu in 143 A.D. can be divided into two main earthquakes. One earthquake feeling area include Longxi, Hanyang(now Gangu county) and Wudu counties is called south area. Another earthquake feeling area include Zhangye, Wuwei and Beidi(now Wuzhong city) counties is called north area. The earthquake epicenter of the south area is located at west of Gangu county, where con- sistence with the initial epicenter from by the earthquake catalogs, so the event can be called west Gangu earthquake. It's magnitude is about 71/4, and the intensity is about nine to ten, the causative structure is the middle segment of north margin active fault zone of Western Qinling. The ep- icenter of the north area is located at east of Wuwei, near the edge of Tenggeli desert. It's magnitude is about 71/2, the intensity is about ten, and the causative structure may be one of main fault zones in the east segment of Qilianshan-Hexi Corridor active fault system.
MA?Er-man , SHI?Yu-cheng , GAO?Xiao-ming , HE?Wen-gui
2007, 29(1):64-68.
Abstract:On October 25, 2003, two destructive earthquakes with Ms6.1 and Ms5.8 occurred one after the other on the boundary between Minle and Shandan counties in Gansu province, which caused 10 persons killed, 46 people injured and about fifty thousands persons lost their homes. The events also caused serious damage to village buildings, communal establishments of water conservancy, lifeline engineering, schools and hospitals. Immediately after the earthquakes, according to the national criterions and regulations, using the methods of spot check, single item check and fill table check, abundant practical data were gained. On this base of data, the disaster area is divided into three assessment sections, the break ratio, the loss ratio and fundamental data of every type building in each assessment section are established. Through statistic analysis on ten items and the professional calculation, a practical assessment of economic loss is figured out.
SHI?Yu-cheng , WANG?Lan-min , MA?Er-man , CHEN?Yong-ming
2007, 29(1):69-74.
Abstract:Based on the field survey of 2003 Minle--Shandan Ms6. 1,5. 8 Twin earthquakes, aspects such as the macroscopic pre-earthquake anomaly, human reaction, life loss, capacity of governmental decision-making, public seismic prevention awareness, social relief effort, implementation of emergency response plan and earthquake rumors are investigated and analyzed, and through it lessons on protecting against and mitigating earthquake disaster are drawn and importance of social factors during seismic disaster relief is emphasized. The study in this paper can provided useful information and insight for earthquake emergency response and relief.
2007, 29(1):75-78,83.
Abstract:The house collapse caused by earthquakes is main earthquake disaster and direct reason of people death in China rural area. In this paper, based on the investigation result of rural building in Gansu province. The houses in rural area are classified according to the structure types, and the seismic destroying mechanism for every type of house are discussed. The result is significant to reconstructing of old houses and design of new buildings in future.
2007, 29(1):79-83.
Abstract:Many large-scale landslides and slide dammed lakes were formed during Haiyuan M8.5 earthquake in 1920 in Lannihe valley of Xiji county, Ningxia province. In this paper, the basic characteristics and the using situation of the slide landforms are expatiated, and the potential environment disaster caused by the landslides is analyzed also. Meanwhile how to explorate and use this landslides landform based on lacal condition, and how to mitigate the disaster are discussed.
2007, 29(1):84-87,93.
Abstract:Based on the field work data of fault plane scratch on Northern Margion Fault of Xinglongshan, Baiyangshugou fault and Xiwan-Leizhuang fault, the tectonic stress field is obtained. With other data related to the contemporary tectonic stress field, the characteristics of tectonic stress field in Lanzhou region are summarized: (1)The direction of the principal stress along the fault zone mainly varies with NNE-NEE. (2)The contemporary tectonic stress field inherites the one in Late Pleistocene. (3)The stress field on surface is concordant with that in depth. (4)The contemporary regional stress field mainly is in a horizontal compression way.
2007, 29(1):88-93.
Abstract:The special soils, which includes loess, frozen soil, soft soil, and swelling soil, distribut widely in China, and are easy to cause disasters. For their particular microstructure, during dynamic loading the responses of special soils are unique and complicate. In recent yeas the dynamic problems of special soils have been the focal points in the field of special soils engineering. In this paper, the history and recent advance of special soil dynamics are reviewed. On this basis the future development strategy of the field is discussed, some study problems are put forward.
2007, 29(1):94-95.
Abstract:The countrywide situation of soil dynamics field in China is given briefly, the important changes occurred in recent years, the shortcomings existed in the field and the directional problems needed to be researched are analyzed in this paper.
2007, 29(1):96-98.
Abstract:Some views and improvement opinions for stipulations ralate to loess in "Code for seismic design of buildings"( GB50011-2001) are put forward. The unfavorable effects of earthquake action to engineering (such as seismic subsidence of loess, liquefaction, negation friction of pile, and so on) are analyzed, and some relative engineering suggestions are given. For special emphasis, the water-bearing state of collapsible loess must be considered when dealing with the effects of earthquake action to engineering.
2007, 29(1):99-103.
Abstract:Some limitations of several current codes when is used in loess area is discussed. As a consequence, the factors influencing the anti-seismic parameters, e.g. field condition and field classification, are expressed. The result reveals the necessity of making the local code. The future research efforts in this field are expected.
Sopyright:China Earthquake Engineering Journal