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1.
K. Onder Cetin T. Leslie Youd Raymond B. Seed Jonathan D. Bray Rodolfo Sancio W. Lettis M. Tolga Yilmaz H. Turan Durgunoglu 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):1083-1092
This paper presents a study of liquefaction-induced ground deformations at the Hotel Sapanca site during the 1999 Kocaeli (Izmit)—Turkey earthquake. The paper discusses: (1) observed ground deformations and displacements after the earthquake, (2) the results of field investigations by means of borings and in situ index tests including standard penetration tests (SPT), static cone penetration tests (CPT) and piezocone (CPTU) tests, (3) analyses of observed ground settlements and lateral deformations by a suite of methods, and (4) comparisons of observed and calculated ground movements. 相似文献
2.
Characterization of liquefaction resistance in gravelly soil: large hammer penetration test and shear wave velocity approach 总被引：2，自引：0，他引：2
Ping-Sien Lin Chi-Wen Chang Wen-Jong Chang 《Soil Dynamics and Earthquake Engineering》2004,24(9-10):675
Gravelly soil is generally recognized to have no liquefaction potential. However, liquefaction cases were reported in central Taiwan in the 1999 Chi-Chi Taiwan earthquake and in the 1988 Armenia earthquake. Thus, further studies on the liquefaction potential of gravelly soil are warranted. Because large particles can impede the penetration of both standard penetration test and cone penetration test, shear wave velocity-based correlations and large hammer penetration tests (LPT) are employed to evaluate the liquefaction resistance of gravelly soils. A liquefied gravelly deposit site during the Chi-Chi earthquake was selected for this research. In situ physical properties of soil deposits were collected from exploratory trenches. Instrumented LPT and shear wave velocity (Vs) measurements were performed to evaluate the liquefaction resistance. In addition, large-scale cyclic triaxial tests on remolded gravelly soil samples (15 cm in diameter, 30 cm in height) were conducted to verify and improve LPT-based and Vs-based correlations. The results show that the LPT and shear wave velocity methods are reasonably suitable for liquefaction assessment of gravelly soils. 相似文献
3.
During the 1999 Chi-Chi, Taiwan earthquake, many sand boiling phenomena were observed in central Taiwan, which caused severe ground settlement and structure damages. According to the installed accelerograms, the peak ground surface horizontal accelerations in the liquefaction-affected areas range from 774.42 to 121.3 gal. The writers carried out an extensive investigation of soil liquefaction in this earthquake. In this paper, we present results of the CPT exploration and post-earthquake liquefaction analysis. Two hundred and seventy five (275) cone penetration test data were collected from the liquefaction-affected areas, and 46 liquefaction case histories and 88 non-liquefaction case histories were derived that can be used to evaluate the accuracy of existing liquefaction evaluation models. In addition, the strength of the liquefied soils after earthquake and the implication of its liquefaction potential in the future event are discussed. 相似文献
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桩靴贯入阻力的准确预测是自升式钻井平台安全作业的前提。通过小比尺模型试验,研究饱和砂土中桩靴贯入速度对筒型桩靴插桩性能的影响,并基于地基承载力理论提出筒型桩靴贯入阻力的计算方法,进而采用CEL有限元方法模拟筒型桩靴的贯入过程,并与试验结果进行比较。研究发现:当模型试验中桩靴贯入速度在0.1～0.3mm/s时,桩靴的贯入可看作是准静态过程,此时贯入阻力变化不大,采用基于地基承载力理论中的Hansen公式和Vesic公式可较为准确地计算出对应某一深度的贯入阻力;CEL有限元方法可有效模拟筒型桩靴的贯入过程,当桩靴的贯入速度为0.1～0.3mm/s时,数值模拟结果与试验结果吻合较好。 相似文献
6.
汶川大地震触发了多处高速远程滑坡,导致了大量的人员伤亡及财产损失。其中,东河口滑坡是这次地震触发的最为典型的高速远程滑坡之一,同时也是目前备受关注、争论颇多的滑坡之一。野外调研结果表明,该滑坡的成因和动力特征主要包括震裂溃屈、水平抛射、碎屑流化和振动液化等4个方面。为了对该滑坡滑动过程中的振动液化这一动力特征进行模拟再现,在东河口滑坡体上采集了具有代表性的滑带土作为试验样品,并以该地震时的实测地震波作为动力输入,利用目前国际上最先进的DPRI环剪试验机,对滑坡滑动过程中的振动液化现象进行了一系列环剪试验研究。结果表明,地震作用过程中,发生在滑坡潜在滑面上的振动液化现象是导致高速远程滑坡产生的一个重要因素;伴随着振动液化过程,滑体的剪切强度迅速降低并产生逐渐增大的剪切位移,为高速远程滑坡的形成提供了条件 相似文献
7.
During the 2003 Sanriku‐Minami earthquake, Japan, a flowslide was triggered on a slope of about 13.5º. The displaced landslide mass developed into a flowslide and deposited on a horizontal rice paddy after traveling approximately 130 m. To study the trigger and movement mechanisms of this landslide, field investigation and laboratory ring‐shear tests were performed. Field investigation revealed that the landslide originated from a fill slope, where a gully was buried for cultivation some decades ago, and shallow ground water was present. Undrained monotonic and cyclic ring‐shear tests on a sample (pyroclastic deposits) taken from the source area revealed that the soil is highly liquefiable, and its steady‐state shear strength can be little affected by overconsolidation. Using the seismic records of the earthquake, probable seismic loadings on the sliding surface were synthesized and applied to the samples in ring‐shear tests, which were performed under undrained or partially drained conditions. The undrained and partially drained tests revealed that shear failure can be triggered by the introduction of seismic loading and formation of excess pore‐water pressure. The generation of excess pore‐water pressure along with increase of shear displacement and the inhibited dissipation of excess pore‐water pressure due to the thickness of the saturated soil layer above the sliding surface probably enabled the continued post‐failure landsliding. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
8.
Pijush Samui 《地震工程与工程振动(英文版)》2007,6(4):331-336
Determining the liquefaction potential of soil is important in earthquake engineering. This study proposes the use of the Relevance Vector Machine (RVM) to determine the liquefaction potential of soil by using actual cone penetration test (CPT) data. RVM is based on a Bayesian formulation of a linear model with an appropriate prior that results in a sparse representation. The results are compared with a widely used artifi cial neural network (ANN) model. Overall, the RVM shows good performance and is proven to be more accurate than the ANN model. It also provides probabilistic output. The model provides a viable tool for earthquake engineers to assess seismic conditions for sites that are susceptible to liquefaction. 相似文献
9.
C. Hsein Juang Susan Hui Yang Haiming Yuan Eng Hui Khor 《Soil Dynamics and Earthquake Engineering》2004,24(9-10):771
As the profession moves toward the performance-based earthquake engineering design, it becomes more important and pressing to examine the uncertainty of the limit state model used for liquefaction potential evaluation. In this paper, the uncertainty of the Robertson and Wride model, a simplified model for liquefaction resistance and potential evaluation based on cone penetration test, is investigated in detail for its model uncertainty in the framework of first-order reliability analysis. The uncertainties of the parameters used in the Robertson and Wride model are also examined. The model uncertainty is estimated by calibration with a fairly large set of case histories. The results show that the uncertainty of the Robertson and Wride model may be characterized with a mean-to-nominal of 0.94 and a coefficient of variation of 0.15 based on the case histories examined. 相似文献
10.
伊兹米特地震的强地震动和地震灾害 总被引：3，自引：0，他引：3
介绍了１９９９年８月１７日土耳其伊兹米特７．４级地震的强地震动和地震灾害,包括：伊兹米特级地震的强地面运动、地震烈度分布、地震震害以及地震破坏原因浅析。 相似文献
11.
Seismic piezocone (SCPTu) data compiled from 86 sites in the greater Christchurch, New Zealand area are used to evaluate several existing empirical correlations for predicting shear wave velocity from cone penetration test (CPT) data. It is shown that all the considered prediction models are biased towards overestimation of the shear wave velocity of the Christchurch soil deposits, demonstrating the need for a Christchurch-specific shear wave velocity prediction model (McGann et al., 2014) [1]. It is hypothesized that the unique depositional environment of the considered soils and the potential loss of soil ageing effects brought about by the 2010–2011 Canterbury earthquake sequence are the primary source of the observed prediction bias. 相似文献
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地震诱发滑坡的危险性分析与预测 总被引：1，自引：0，他引：1
结合地震滑坡的特点和相关文献研究,介绍了地震力的分析方法、地震滑坡的机理、地震危险性分析的方法、地震活动性参数的确定方法以及场点地震危险性概率计算原则。将两种地震诱发滑坡预测结果进行对比,分析结果表明,地震滑坡危险区主要集中在中国西部地区（川、滇、甘、陕、新疆等省区）及中国台湾地区,随预测年限的增加场地的地震滑坡危险性也随之增高,地震崩塌滑坡的危险区域明显加大。 相似文献
13.
Graeme H.McVerry 《地震工程与工程振动(英文版)》2010,9(2):177-187
A landslide displacement (DLL) attenuation model has been developed using spectral intensity and a ratio of critical acceleration coefficient to ground acceleration coefficient. In the development of the model,a New Zealand earthquake record data set with magnitudes ranging from 5.0 to 7.2 within a source distance of 175 km is used. The model can be used to carry out deterministic landslide displacement analysis,and readily extended to carry out probabilistic seismic landslide displacement analysis. DLL attenuation models have also been developed by using earthquake source terms,such as magnitude and source distance,that account for the effects of earthquake faulttype,source type,and site conditions. Sensitivity analyses show that the predicted DLL values from the new models are close to those from the Romeo model that was developed from an Italian earthquake record data set. The proposed models are also applied to an analysis of landslide displacements in the Wenchuan earthquake,and a comparison between the predicted and the observed results shows that the proposed models are reliable,and can be confidently used in mapping landslide potential. 相似文献
14.
Field investigations following the 2008 Ms8.0 Wenchuan earthquake identified 118 liquefaction sites, most of which are underlain by gravelly sediment in the Chengdu Plain and adjacent Mianyang area, in the Sichuan Province. Gravel sediment in the Sichuan province is widely distributed; hence it is necessary to develop a method for prediction and evaluation of gravel liquefaction behavior. Based on liquefaction investigation data and in-situ testing, and with reference to existing procedures for sandy soil liquefaction evaluation, a fundamental procedure for gravel liquefaction evaluation using dynamic penetration tests (DPT) is proposed along with a corresponding model and calculation formula. The procedure contains two stages, i.e., pre-determination and re-determination. Pre-determination excludes impossible liquefiable or non-liquefiable soils, and re-determination explores a DPT-based critical N120 blows calculation model. Pre-determination includes three criteria, i.e., geological age, gravel contents, gravel sediment depths and water tables. The re-determination model consists of five parameters, i.e., DPT reference values, gravel contents, gravel sediment depths, water tables and seismic intensities. A normalization method is used for DPT reference values and an optimization method is used for the gravel sediment depth coefficient and water table coefficient. The gravel liquefaction evaluation method proposed herein is simple and takes most influencing factors on gravel sediment liquefaction into account. 相似文献
15.
1976年唐山大地震引发了范围广、灾害重的液化震害。铁道部科学研究院等单位于1977、1978年对液化场地进行了单桥静力触探测试。但单桥静力触探在数据指标方面存在缺陷,与国际标准不接轨。中国地震局工程力学研究所与东南大学等单位于2007年对上述唐山地区部分测点再次进行了孔压静力触探（CPTU）测试。本文通过对比2次静力触探数据,利用Robertson土质分类图,进行新孔压静力触探数据土类分层检验,将土类检验结果与单桥静力触探测试时钻孔柱状图进行对比,发现大部分测点土层土类均能较好对应,现场测试力学指标沿深度变化趋势较相符,仅剔除了错误点T2、T3。对所有测点选定液化层,分别建立基于单桥静力触探测试比贯入阻力ps和基于孔压静力触探测试锥尖阻力qc的液化数据库。利用基于静力触探测试（CPT）的我国规范液化判别方法检验了2个数据库,发现对单桥静力触探测试的数据库液化判别效果好,而对孔压静力触探测试的数据库液化判别效果较差,说明经过30年的时间,土层液化可能已发生较大改变。因此,基于孔压静力触探测试的液化数据库可靠性较低,基于该数据库对液化判别方法进行改进意义较小。 相似文献
16.
Tadahiro Fukusumi Hitodhi Ozaki Masao Koba 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):893-899
During the 1995 Hyogoken Nambu earthquake in Kobe, the ground motion at the filled man-made islands in the Kobe harbor was not as severe as that at the mainland. The building damage was also less compared to that on the mainland. It was found by comparative study of earthquake records that the magnitude of acceleration response on the ground surface decreases at the islands as opposed to the mainland. One dimensional effective stress analysis is adopted in this study. Input data has been generated from test results, e.g. the SPT N-value by standard penetration test and shear wave velocity Vs by PS logging. Results obtained by the analyses showed good agreement with the observed records, which is an indication of the suitability of the adopted analysis procedure. From this study, the followings are concluded. By the increase of SPT N-value of the filled layers, liquefaction near ground surface is restrained and damage modes such as ejection of water and soil can be prevented. Since the ground profile at the islands is that considerably soft filled layer and marine clay layers, etc. are present and the thickness of the surface layer is large, the initial natural period of the ground is above 1 s and the natural period is elongated further under the earthquake excitation, which is deemed to be the principal reason for the reduction of the earthquake motion at the ground surface. 相似文献
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S. Bernardie E. Foerster H. Modaressi 《Soil Dynamics and Earthquake Engineering》2006,26(11):1038-1048
The destructive 1999 Chi–Chi earthquake (Mw 7.5) was the largest inland earthquake in Taiwan in the 20th century. Several observations witness the non-linear seismic soil response in sediments during the earthquake. In fact, large settlements as well as evidence of liquefaction attested by sand boils and unusual wet ground surface were observed at some sites. In this paper, we present a seismic response simulation performed with CyberQuake software on a site located within the Chang-Hwa Coastal Industrial Park during the 1999 Chi–Chi earthquake in Taiwan. A non-linear multi-kinematic dynamic constitutive model is implemented in the software. Computed NS, EW and UP ground accelerations obtained with this model under undrained and two-phase assumptions, are in good agreement with the corresponding accelerations recorded at seismic station TCU117, either for peak location, amplitudes or frequency content. In these simulations, liquefaction occurs between depths 1.3 and 11.3 m, which correspond to the observed range attested by in place penetration tests and other liquefaction analyses. Moreover, the computed shear wave velocity profile is very close to post-earthquake shear wave velocity profile derived from correlations with CPT and SPT data. Finally, it is shown that in non-linear computations, even though a 1D geometry is considered, it is necessary to take into account the three components of the input motion. 相似文献
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C. Hsein Juang Haiming Yuan Der-Her Lee Chih-Sheng Ku 《Soil Dynamics and Earthquake Engineering》2002,22(3)
In the early morning (1:47 Taiwan time) of September 21, 1999, the largest earthquake of the century in Taiwan (Mw=7.6, ML=7.3) struck this island country. The earthquake killed more than 2400 people and caused great destruction to buildings, bridges, dams, highways, and railways. One of the causes for heavy damages to the structures is soil liquefaction and ground settlement during the earthquake. In this paper, investigation of soil liquefaction and case histories of liquefaction are presented. Three CPT-based simplified methods, the Robertson method, the Olsen method, and the Juang method, are examined using the case histories derived from the Chi-Chi earthquake. The results of the comparison show that the Juang method is more accurate than the two methods in predicting liquefaction potential of soils based on the cases derived from the Chi-Chi earthquake, although all three methods are quite comparable in accuracy. 相似文献
19.
通过二维离散元模拟斜坡地基静力触探试验,研究试验过程中锥尖阻力的变化以及斜坡地基的宏微观力学响应。结果表明:归一化锥尖阻力峰值在坡角较小时无明显提升,在坡角足够大时提升明显,稳定值随着坡角增大略微减小,说明斜坡边界对表层土力学性能影响明显,而对深层土影响较弱;锥尖贯入过程中,斜坡地基探杆两侧土体变形不对称,坡上一侧膨胀,坡下一侧压缩,不对称性随着坡角增大而增大;贯入到表层时,探杆两侧微观接触力链不对称,坡上一侧具有更大应力,但当贯入到深层时力链趋向于对称,其临界深度随着坡角增大而增大,与坡角呈近似线性关系。 相似文献
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2010年4月14日青海省玉树县发生了MS7.1地震.文中基于现场考察与遥感影像目视解译的方法,对玉树地震滑坡进行分析,并制作了玉树地震滑坡空间分布图.结果表明,该地震触发了约2 036处滑坡灾害,总面积约1.194km2;地震滑坡分布受主地表破裂控制作用强烈;滑坡类型多样,但以崩塌型滑坡为主;滑坡有5种成因机制:人工开挖坡脚型、地表水入渗致坡体震动滑动型、断裂错断震动型、震动型、后期冰雪融化或降雨入渗型;除地震主地表破裂外,还有许多坡体裂缝,主要分布在主地表破裂带SE端的SW盘,该部位在地震中受到了强烈的挤压作用. 相似文献