Seismic response of flexible cantilever retaining walls with dry backfill     

《Geomechanics and Geoengineering》2013,8(4):275-289

Failure of retaining walls during earthquakes has occurred many times in the past. Although significant progress has been made in analysing the seismic response of rigid gravity type retaining walls, considerable difficulties still exist in the seismic-resistant design of the flexible cantilever type of retaining walls because of the complex nature of the dynamic soil–structure interaction. In this paper the seismic response of cantilever retaining walls with dry backfill is simulated using centrifuge modelling and numerical modelling. It is found that bending moments on the wall increased significantly during an earthquake. After the end of base shaking, the residual moment on the wall was significantly higher than the moment under static loading. The numerical simulation is able to model quite accurately the main characteristics of acceleration, bending moment, and displacement recorded in the centrifuge test.  相似文献   

Reliability analysis of strength of cement treated soils     

《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2013,7(3-4):157-162

The design strength of cement treated soils and its variability are influenced by various contributing factors such as inherent variability of the soft ground as well as variations in the quantities of the additives used for improvement. To consider these variations, geotechnical designs use the factor of safety approach. This paper shows that the reliability-based analysis enables a rational choice of a design strength value for the cement-stabilised soft soil, considering the variations in the influencing input parameters in an appropriate manner. An approach for identifying the important variables governing the strength behaviour of improved soft soils is also illustrated.  相似文献   

浅谈海洋风电勘察安全风险控制          下载免费PDF全文

许启云  周光辉  洪炉  牛美峰 《探矿工程》2013,40(1):81-84

海洋风电勘察不同于陆地,钻探要依靠水上平台,为了确保海洋勘察施工的安全,应考虑各种危险有害因素,及有效评估安全风险,再通过编制一系列的安全措施予以防范,以确保海洋勘察施工的需要。  相似文献   

安徽水稻土中镉元素生态安全评价标准探讨     

贾十军 《安徽地质》2013,(2):132-136

土壤中镉元素稳定的残渣态所占比例在重金属中为最低,其赋存形态以离子态为主,易被植物吸收的活性态较高,生态危害较大。稻米镉元素与土壤镉元素具有显著的正相关性。根据区域土壤镉元素与稻米镉元素含量及稻米镉超标率关系,将水稻种植土壤分为生态安全土壤、具生态安全风险土壤及生态安全高风险土壤,提出了土壤镉元素生态安全定量分级标准。  相似文献   

门源6.4级、共和7.0级地震前后波速比变化特征   总被引：2，自引：0，他引：2  

都昌庭  徐兰芬  冀金梅 《高原地震》1997,(2)

通过来用门源台、湟源台所记录的地震资料，对1986年门源6．4级地震、1990年共和7．0级地震前后进行波速比-时空分析，发现两次地震前后其时间分布形态为持续低值-恢复-发震的现象，空间分布为圆形、椭圆形的异常区，震后异常区消失。  相似文献   

准噶尔盆地陆东-五彩湾地区石炭系火山岩电性与地震响应特征   总被引：3，自引：1，他引：3       下载免费PDF全文

吴晓智  李建忠  杨迪生  张丛侦  侯连华  郑曼 《地球物理学报》2011,54(2):481-490

勘探实践证实,准噶尔盆地石炭系已成为一套现实勘探层系;陆东-五彩湾地区石炭系火山岩体规模大、分布广,是重要的天然气储集体;火山岩储层有效性主要受不整合、岩性、岩相控制,识别火山结构、火山岩岩性、岩相成为判别储层有效性的关键.由于主要目的层巴塔玛依内山组特殊的三段式火山岩组合层序结构,为通过测井、地震物探手段识别火山岩岩...  相似文献   

地震火山地层学及其在我国火山岩盆地中的应用   总被引：9，自引：3，他引：9       下载免费PDF全文

王璞珺  张功成  蒙启安  鲁宝亮  朱德丰  孙晓猛 《地球物理学报》2011,54(2):597-610

火山地层,物源来自于地下,搬运和分散方式有岩浆流、碎屑流、空落堆积及它们的再搬运,是不同于所有沉积地层的"异化地层".与层序地层学研究沉积地层类似,火山地层学着重研究火山岩系的层序界面和内部充填样式,通过地震层序分析刻画成因地层单元和地层对比关系.应用地震火山地层学在南海北部陆缘带识别出向海倾斜反射(SDR)、向陆流、...  相似文献   

Electromagnetic Abnormity Observed at Sujiatun Seismic Station and Its Relation to Earthquake     

Li Mei 《中国地震研究》2006,20(3):295-304

INTRODUCTIONShort-termearthquake prediction is one of the most challenging targets in earth science today.Manyrecent reports have presented examples fromseveral regions of the world by which associationsbetween possible electromagnetic precursors and earthquakes become more and more plausible(Eftaxias ,et al .,2003) . At the same time ,electromagnetic abnormity,as one of the short-termearthquake precursors ,is recognized by more and more experts in some countries . Pre-earthquakeelectroma…  相似文献   

Assessment of liquefaction potential based on peak ground motion parameters   总被引：1，自引：0，他引：1  

Rolando P. Orense   《Soil Dynamics and Earthquake Engineering》2005,25(3):225-240

Conventionally, evaluation of liquefaction potential of loose saturated cohesionless deposits as specified in Japanese design codes employs peak ground acceleration (PGA). However, recent large-scale earthquakes in Japan revealed that liquefaction at some sites did not occur even though large PGAs were recorded at or near these sites. As an alternative approach, an evaluation procedure based on peak ground motion parameters, i.e. incorporating both PGA and the peak ground velocity (PGV), is proposed. By performing parametric studies using one-dimensional seismic response analysis and formulating regression models, seismic-induced shear stresses within the deposit are expressed in terms of peak ground motion parameters at the surface, and these are used to calculate the factor of safety against liquefaction. Application to case histories in Japan indicates that the proposed two-parameter equation can adequately account for the occurrence and non-occurrence of liquefaction at various sites as compared to the conventional PGA-based approach. Moreover, analyses of several strong motion records at various sites show that liquefaction may occur when PGA≥150 gal and PGV≥20 kine, indicating that these values can serve as thresholds in assessing the possible occurrence of liquefaction.  相似文献   

1987年寻乌地震前的地震活动性异常特征及其相关讨论     

吕坚  高建华  刘吉夫  黄双凤 《华南地震》2002,22(4):28-33

利用“八五”，“九五”地震预报攻关研究的成果。对1987年寻乌Ms5.5级地震前的地震活动性异常特征进行了再研究。结果表明，此次地震前出现小震活动空区，地震活动“增强-平静”，前兆性震群活动等多项明显的地震活动性异常。这些异常还表现出一些中期向短期过渡的特征。对将来主震的中短期预测具有一定的参考价值。  相似文献