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1.
1INTRODUCTIONReservoirsedimentationisrecognizedasoneofthemainproblemsafectingtheeconomicsofmanywaterresourcesprojects.Manmad...  相似文献   

2.
长江三峡工程周边地区的采矿诱发地震   总被引:6,自引:2,他引:6       下载免费PDF全文
胡毓良  杨清源 《地震地质》1998,20(4):62-360
地震观测和实地调查表明,长江三峡工程周缘广泛存在采矿诱发地震。采矿诱发地震主要是由于矿山采空区的出现使浅部地壳差应力增大岩体失稳而产生的,它们不同于天然地震。水库蓄水前应对这些地震的背景进行详细研究。在进行区域地震震情分析和预报、区域应力场及活动断裂研究时应严格加以区别  相似文献   

3.
天山地区中强地震预报判据及方案   总被引:1,自引:1,他引:1  
对新疆6级地震成组活动与7级地震的相关性进行了总结。结合天山地区不同构造环境,开展中强地震孕育阶段不同区域地震活动图像演化和强震短期前兆异常综合特征研究,在总结天山地区中短期异常特征及预报判据基础上,提出中短期阶段预报方案。预报方案:①时间预测。南天山在地震平静背景下,局部地区出现较明显的地震增强现象;北天山3~4级地震出现增强-平静-显著地震过程;大范围前兆观测出现同步异常变化等。②地点预测。地震活动增强区、空区周围、条带端部或空段、显著事件周围,定点前兆短期异常相对集中区域等,可做为地震发生的预测地点。③强度预测。预测区周围历史地震强度、新疆5级地震平静持续时间、震前地震活动强度等可做为强度预测的参考。  相似文献   

4.
IINTRODUCTIONTheYellowRiverisfamousforitsheaVysedimentloadandcompledpluvialprocessesobviousadvanceshavebeenmadeinthetwo-dimensionalsedimentmathematicalmodel.Amongtile1llodelscreatedbeforethemechanismofsedimenttransportandrelatedphysicalparametel's,suchassedimentvelocity,sedimentcan'yingcapacityandriverfi.ictionetc.arenotyetundel.stoodvery\veil.Thesynchronousobserveddataoftheflowwithsediment,especiallyathyperconcentration,arenotenougllforthemodelcalibration.Thereforethedevelopmentoftwo-di…  相似文献   

5.
工程VSP技术在三峡坝区中的应用   总被引:2,自引:0,他引:2       下载免费PDF全文
通过对长江三峡枢纽工程坝区白岩尖1井的工程VSP测试,在采用四分量采集、双子波监控和复杂波场的波形识别等技术的基础上,提出反映岩石特性的多种动弹模量,综合解释井口周围复杂的花岗岩岩体内部风化带分布和裂隙及岩脉充填分布.  相似文献   

6.
小浪底水利枢纽位于河南省洛阳市以北约40km的黄河干流上,上距三门峡水库130km,下距郑州市京广铁路大桥115km。工程位于黄河中游最后一段峡谷的出口,处于承上启下、控制黄河水沙的关键部位。它是一座以防洪、防凌、减淤为主,兼顾供水、灌溉、发电、除害兴利综合利用的枢纽工程,是“治黄”的关键工程,亦是国家“八五”期间的重点大型工程。结合黄河小浪底水利枢纽工程的实际需要,我们在地下厂房区做了两组地震跨  相似文献   

7.
8.
小浪底水利枢纽位于河南省洛阳市以北约40km的黄河干流上,上距三门峡水库130km,下距郑州市京广铁路大桥115km。工程位于黄河中游最后一段峡谷的出口,处于承上启下、控制黄河水沙的关键部位。它是一座以防洪、防凌、减淤为主,兼顾供水、灌溉、发电、除害兴利综合利用的枢纽工程,是“治黄”的关键工程,亦是国家“八五”期间的重点大型工程。结合黄河小浪底水利枢纽工程的实际需要,我们在地下厂房区做了两组地震跨  相似文献   

9.
This article addresses sediment research carried out for the Three Gorges Project since 1993, when the construction of the project was formally started. Emphasis of the research has been placed on the solution of relevant problems arising from design and construction of various structures, including sedimentation problems in the Chongqing reach; layout of the upper lock approach channel and ways and means to mitigate its deposition; increasing reservoir capacity by optimizing reservoir operation; compensating depth of flow required by navigation below the Gezhouba Project caused by scouring; mitigation of adverse effects of erosion on the reach from Zhicheng to Jiangkou; and evaluating scour of the Jinjiang reach caused by releasing flows of low concentrations from the TGP. In addition, reduction of the sediment load entering into the reservoir area of the TGP in the recent years as well as that expected of the projected construction of large hydropower stations on the Jinsha River upstream of the TGP reservoir is also noted and discussed.  相似文献   

10.
彭亮  吴彬  沈军  唐丽华  陈建波 《内陆地震》2008,22(3):234-242
利用地震危险性概率分析方法对大(Ⅰ)型一等工程-某大型水利枢纽工程所在的场址进行地震危险性分析;该拟建工程场址所在的西昆仑地震带是新疆境内地震活动强度最高、频度最大的地震带,拟建工程坝高库大,为了进行准确的地震危险性分析研究。本研究根据区域地震活动性及地震构造研究成果,确定了地震活动性参数,按照构造类比、历史地震重演原则划分了潜在震源区;在分析了区域地震活动环境和地震构造等因素后,综合评价其对场地地震危险性的影响;根据确定的地震动衰减关系及地震带、潜在震源区的地震活动性参数,应用概率方法计算得出了场地不同概率水平的水平向基岩峰值加速度。其结果做为适合该水库的工程场地地震危险性分析结论,用于指导工程选址、设计、抗震设防。  相似文献   

11.
选取1970年至1997年时间段内发生在山西地区的逐年最大震级,采用门限自回归原理进行建模,经过反复对比,选取最佳模型,预测得知该区未来3年(至2000年)发生强震(Ms>6.0)的可能性不大。  相似文献   

12.
China is the country with the challenge of severe earthquake disaster. In order to mitigate the disaster and save lives, emergency response and rescue work after an earthquake are deployed and led by the Chinese governments at all level, the effectiveness of which has been proved. In such work, how to quickly evaluate the seismic intensity in meizoseismal area is a crucial issue at the early period after the earthquake. It is the foundation to estimate the disaster losses and decide the scale of rescue teams and materials. However, at the early period only a few physical parameters of the earthquake can be acquired and some of them may even be inaccurate. An evaluation model of seismic intensity in meizoseismal area is investigated and presented by statistic method in this study. After an earthquake there are four authoritative parameters officially released by China Earthquake Administration generally within ten minutes:earthquake magnitude (MS), focal depth, latitude and longitude position, and the occurrence time. They are good candidate input parameters of the evaluation model. We collect the information of 215 historical earthquake occurring in China from 1966 to 2013, including:The four parameters and the seismic intensity in meizoseismal area. Through statistical analysis we find the seismic intensity in meizoseismal area has high correlation with the earthquake magnitude (MS) and the focal depth and then select them as the formal input parameters. After further investigation a generalized linear model is built to fit the relationship between the seismic intensity in meizoseismal area, earthquake magnitude (MS) and the focal depth. The effectiveness of the model is validated by the Sig value and F value from theoretic perspective. The validation also includes the application of the model in real earthquakes occurring from 2014 to 2017. After the earthquakes, the seismic intensities in meizoseismal area have been quickly estimated and used in the command of national earthquake disaster emergency relief. The applications in real earthquakes get good results. Finally, the robustness of the model is analyzed. We respectively verify the influences of the earthquake magnitude (MS) and the focal depth and find the seismic intensity in meizoseismal area is more sensitive to the earthquake magnitude. Under the condition of the same focal depth, when the change of the earthquake magnitude is up to 0.5, the change of the seismic intensity will reach to 1. However, in order to cause same change of the seismic intensity, the difference of the focal depth will be 10 kilometers. Basically, these changes derived from the model meet the situation of historical earthquakes.  相似文献   

13.
朱守彪  石耀霖 《地震学报》2002,24(2):162-168
应力释放模型过去主要用于研究大范围历史大地震活动规律.本文对应力释放模型进行了改进,对其能否运用于区域更小、时段更短、震级更低的情况进行了探讨;以台湾地区近百年6级以上地震为例的研究结果表明,应力释放模型仍然适用.在回溯性的地震预测检验中,用改进的应力释放模型计算出台湾地区地震发生的条件概率强度,并用其预测6级以上地震的发震时刻.结果表明,其预测精度优于泊松模型.   相似文献   

14.
岩浆岩的模拟实验,由于其实验条件的可控性,能够较好地研究岩浆岩的影响因素及其机理.本文实验表明,岩浆岩的磁组构除与成岩时的流动有关外,还受地磁场及重力场的影响,当流动较强时,岩浆岩的磁线理与流动方向有很好的一致性;当流动较弱时,地磁场方向的影响更大.另外,由于岩浆岩较弱的磁各向异性,以及成岩后期各种因素的影响,使其机理呈现复杂性,主轴方位具有分散性.  相似文献   

15.
岩浆岩的模拟实验,由于其实验条件的可控性,能够较好地研究岩浆岩的影响因素及其机理.本文实验表明,岩浆岩的磁组构除与成岩时的流动有关外,还受地磁场及重力场的影响,当流动较强时,岩浆岩的磁线理与流动方向有很好的一致性;当流动较弱时,地磁场方向的影响更大.另外,由于岩浆岩较弱的磁各向异性,以及成岩后期各种因素的影响,使其机理呈现复杂性,主轴方位具有分散性.  相似文献   

16.
利用较大岩石样品,实验研究了加载时同时向样品内注水过程中穿过样品超声波波速和尾波Qc值的变化特征。结果表明,在压力作用下,岩石破坏前通过岩石的尾波Qc值下降,如果有压力水进入,则岩石的尾波值Qc会大幅下降。因此,我们可以认为,地壳岩石破坏发生地震前的尾波下降的物理机制是岩石在压力产生扩容裂隙及流体进入裂隙双重作用的结果。  相似文献   

17.
50°S以南海域的感热潜热通量的模式计算   总被引:1,自引:0,他引:1       下载免费PDF全文
应用美国宇航局Goddard地球观测系统(GoddardEarthObservingSystem简称GEOS)四维资料同化系统(DataAssimilationSystem简称DAS),计算和分析了50°S以南海域夏季的感热、潜热通量.结果表明,在50°S以南海域潜热通量都为正值,感热通量在大部分海域亦为正值,但在有些海域可出现负值.感热和潜热通量随纬向呈高值区和低值区交替分布,通量低值区与海表温度低值槽区往往相符.  相似文献   

18.
LABRIEFINTRODUCTIONOFRANDUNIRRIGATIONDISTRICTYellowRiverisoneofthemainWaterresourcesinNOrthChina.SincethefiftiesirrigationbydivertingwaterfromtheYellowforerdevelOPssteadily.AstheYdlowforerisaheavilysacmentsladenone,sedimentisdiVertedsimultaneouslywhenwaterisdiverted.HOwtoproperlytreatthedivertedsedimentboomesoneOfthekeyproblemsrestrichngthesustainingdevelOPmentofthCwaterresourcesinthatarea.LongchStanceconvopngsedimentisoneofthemainmeasuresfordealingwiththediVertedsedim…  相似文献   

19.
白超英 《内陆地震》1989,3(4):308-313
本文将新疆境内分成六个地震活动区,以马氏模型为基础,论述了Ms≥6.0级地震的区域迁移概率分布,所得结果表明,由1900—1988年资料所得模型的内符精度较高,合格率为85.7%,但由1900—1979年资料所得模型外推1980—1988年状态出现的概率分布时,符合程度有所降低。结合Ms≥6.0级地震年发生概率分布,则Ms≥6.0级地震的区域迁移概率分布可作为中期预报方法应用。  相似文献   

20.
西宁市活断层地震构造模型初步研究   总被引:1,自引:0,他引:1  
在西宁市城市活断层探测的基础上,对城市活断层与地层褶皱变形的关系进行了研究,认为湟水河断层和NW向的湟水河北岸断层为背斜顶部张性断层,南川河断层为褶皱不均匀变形形成的横向撕裂断层,北川河东岸断层为向斜核部或翼部发育的挤压断层。并根据褶皱变形平衡剖面和重力资料反演,推测了褶皱变形滑脱面深度,初步建立了西宁市城市活断层的地震构造模型。依据地震构造模型,对城市活断层的发震能力进行了讨论  相似文献   

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